Biochemistry, Genetics and Molecular Biology › Molecular Biology

Glycosylation and Glycoproteins Research

Works Count: 121567

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Description

This cluster of papers explores the diverse roles of glycosylation in health and disease, with a focus on its implications in cancer, immune system function, and therapeutic development. It covers topics such as the biological functions of glycans, protein glycosylation, sialic acids, mucins, and the interplay between glycosylation and various cellular mechanisms.

Keywords

Glycosylation; Glycans; Cancer; Immune System; Mucins; Protein Glycosylation; Sialic Acids; Lectins; O-GlcNAc; Therapeutics

Glycosylation in cancer: mechanisms and clinical implications

2015-08-20

Salomé S. Pinho , Celso A. Reis

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Cloning and expression of a cell surface receptor for advanced glycosylation end products of proteins.

1992-07-01

Michael P. Neeper , Ann Marie Schmidt , J Brett +6 more

Advanced glycosylation end products of proteins (AGEs) are nonenzymatically glycosylated proteins which accumulate in vascular tissue in aging and at an accelerated rate in diabetes. A approximately 35-kDa polypeptide with … Advanced glycosylation end products of proteins (AGEs) are nonenzymatically glycosylated proteins which accumulate in vascular tissue in aging and at an accelerated rate in diabetes. A approximately 35-kDa polypeptide with a unique NH2-terminal sequence has been isolated from bovine lung and found to be present on the surface of endothelial cells where it mediates the binding of AGEs (receptor for advanced glycosylation end product or RAGE). Using an oligonucleotide probe based on the amino-terminal sequence of RAGE, an apparently full-length cDNA of 1.5 kilobases was isolated from a bovine lung cDNA library. This cDNA encoded a 394 amino acid mature protein comprised of the following putative domains: an extracellular domain of 332 amino acids, a single hydrophobic membrane spanning domain of 19 amino acids, and a carboxyl-terminal domain of 43 amino acids. A partial clone encoding the human counterpart of RAGE, isolated from a human lung library, was found to be approximately 90% homologous to the bovine molecule. Based on computer analysis of the amino acid sequence of RAGE and comparison with databases, RAGE is a new member of the immunoglobulin superfamily of cell surface molecules and shares significant homology with MUC 18, NCAM, and the cytoplasmic domain of CD20. Expression of the RAGE cDNA in 293 cells allowed them to bind 125I-AGE-albumin in a saturable and dose-dependent manner (Kd approximately 100 nM), blocked by antibody to RAGE. Western blots of 293 cells transfected with RAGE cDNA probed with anti-RAGE IgG demonstrated expression of immunoreactive protein compared to its absence in mock-transfected cells. These results suggest that RAGE functions as a cell surface receptor for AGEs, which could potentially mediate cellular effects of this class of glycosylated proteins.

The Lectins: Carbohydrate-Binding Proteins of Plants and Animals

1978-01-01

Irwin Goldstein , Colleen E. Hayes

Methods for the quantitative estimation of N-acetylneuraminic acid and their application to hydrolysates of sialomucoids

1961-11-01

David Aminoff

Research Article| November 01 1961 Methods for the quantitative estimation of N-acetylneuraminic acid and their application to hydrolysates of sialomucoids D AMINOFF D AMINOFF Search for other works by this … Research Article| November 01 1961 Methods for the quantitative estimation of N-acetylneuraminic acid and their application to hydrolysates of sialomucoids D AMINOFF D AMINOFF Search for other works by this author on: This Site PubMed Google Scholar Biochem J (1961) 81 (2): 384–392. https://doi.org/10.1042/bj0810384 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Cite Icon Cite Get Permissions Citation D AMINOFF; Methods for the quantitative estimation of N-acetylneuraminic acid and their application to hydrolysates of sialomucoids. Biochem J 1 November 1961; 81 (2): 384–392. doi: https://doi.org/10.1042/bj0810384 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsBiochemical Journal Search Advanced Search This content is only available as a PDF. © 1961 The Biochemical Society1961 Article PDF first page preview Close Modal You do not currently have access to this content.

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PROTEIN MEASUREMENT WITH THE FOLIN PHENOL REAGENT

1951-11-01

OliverH. Lowry , NiraJ. Rosebrough , A. Farr +1 more

Since 1922 when Wu proposed the use of the Folin phenol reagent for the measurement of proteins (l), a number of modified analytical procedures ut.ilizing this reagent have been reported … Since 1922 when Wu proposed the use of the Folin phenol reagent for the measurement of proteins (l), a number of modified analytical procedures ut.ilizing this reagent have been reported for the determination of proteins in serum (2-G), in antigen-antibody precipitates (7-9), and in insulin (10).Although the reagent would seem to be recommended by its great sensitivity and the simplicity of procedure possible with its use, it has not found great favor for general biochemical purposes.In the belief that this reagent, nevertheless, has considerable merit for certain application, but that its peculiarities and limitations need to be understood for its fullest exploitation, it has been studied with regard t.o effects of variations in pH, time of reaction, and concentration of reactants, permissible levels of reagents commonly used in handling proteins, and interfering subst.ances.Procedures are described for measuring protein in solution or after precipitation wit,h acids or other agents, and for the determination of as little as 0.2 y of protein. MethodReagents-Reagent A, 2 per cent N&OX in 0.10 N NaOH.Reagent B, 0.5 per cent CuS04.5Hz0 in 1 per cent sodium or potassium tartrabe.Reagent C, alkaline copper solution.Mix 50 ml. of Reagent A with 1 ml. of Reagent B. Discard after 1 day.Reagent D, carbonate-copper solution, is the same as Reagent C except for omission of NaOH.Reagent E, diluted Folin reagent.Titrate Folin-Ciocalteu phenol reagent ((II), Eimer and Amend, Fisher Scientific Company, New York) with NaOH t.o a phenolphthalein end-point.On the basis of this titration dilute the Folin reagent (about 2-fold) to make it 1 N in acid.Working standards may be prepared from human serum diluted IOO-to lOOO-fold (approximately 700 to 70 y per ml.).These in turn may be checked against a standard solution of crystalline bovine albumin (Armour and

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Morphological heterogeneity among Salmonella lipopolysaccharide chemotypes in silver-stained polyacrylamide gels

1983-04-01

P J Hitchcock , Teresa M. Brown

The morphological heterogeneity of lipopolysaccharides (LPSs) among salmonella mutants with different LPS chemotypes was analyzed in silver-stained polyacrylamide gels. The biochemical differences in the LPS chemotypes were reflected in the … The morphological heterogeneity of lipopolysaccharides (LPSs) among salmonella mutants with different LPS chemotypes was analyzed in silver-stained polyacrylamide gels. The biochemical differences in the LPS chemotypes were reflected in the unique profiles of the purified LPSs. The LPS profiles in the whole-cell lysates were also unique for each chemotype. (Whole-cell lysates were assessed by a method which preferentially silver stains LPS and by a proteinase K digest of whole-cell lysates. The silver-stained LPS profiles of proteinase K-digested lysates were similar to the homologous purified LPS and could be used to preliminarily characterize the LPS chemotype before purification.) In summary, biochemical variation in LPS composition can be detected in silver-stained polyacrylamide gels.

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Siglecs and their roles in the immune system

2007-03-23

Paul R. Crocker , James C. Paulson , Ajit Varki

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Isolation of pure IgG1, IgG2a and IgG2b immunoglobulins from mouse serum using protein A-Sepharose

1978-07-01

Peter L. Ey , Stephen J. Prowse , C. R. Jenkin

Further improvements in the plaque technique for detecting single antibody-forming cells.

1968-04-01

Alastair J. Cunningham , A Szenberg

A simple technique for detecting plaque-forming cells is described. It combines the sensitivity and improved optical conditions of the previously reported monolayer technique with the screening power and ease of … A simple technique for detecting plaque-forming cells is described. It combines the sensitivity and improved optical conditions of the previously reported monolayer technique with the screening power and ease of quantification of the original agar-plate method.

A new variant of glycoprotein CD44 confers metastatic potential to rat carcinoma cells

1991-04-01

Ursula Günthert , Martin Hofmann‐Apitius , W. Rudy +7 more

Carbohydrate-binding modules: fine-tuning polysaccharide recognition

2004-09-07

A.B. Boraston , David N. Bolam , Harry J. Gilbert +1 more

The enzymic degradation of insoluble polysaccharides is one of the most important reactions on earth. Despite this, glycoside hydrolases attack such polysaccharides relatively inefficiently as their target glycosidic bonds are … The enzymic degradation of insoluble polysaccharides is one of the most important reactions on earth. Despite this, glycoside hydrolases attack such polysaccharides relatively inefficiently as their target glycosidic bonds are often inaccessible to the active site of the appropriate enzymes. In order to overcome these problems, many of the glycoside hydrolases that utilize insoluble substrates are modular, comprising catalytic modules appended to one or more non-catalytic CBMs (carbohydrate-binding modules). CBMs promote the association of the enzyme with the substrate. In view of the central role that CBMs play in the enzymic hydrolysis of plant structural and storage polysaccharides, the ligand specificity displayed by these protein modules and the mechanism by which they recognize their target carbohydrates have received considerable attention since their discovery almost 20 years ago. In the last few years, CBM research has harnessed structural, functional and bioinformatic approaches to elucidate the molecular determinants that drive CBM–carbohydrate recognition. The present review summarizes the impact structural biology has had on our understanding of the mechanisms by which CBMs bind to their target ligands.

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Über die Extraktion von Bakterien mit Phenol/Wasser

1952-03-01

Otto Westphal , O. Lüderitz , Fritz Bister

Es werden zwei einfache Verfahren zur Extraktion von Bakterien mit Phenol/Wasser angegeben. Nach Behandlung von gramnegativen Bakterien mit Phenol/Wasser-Emulsionen in der Kälte während weniger Minuten erhält man in der wäßrigen … Es werden zwei einfache Verfahren zur Extraktion von Bakterien mit Phenol/Wasser angegeben. Nach Behandlung von gramnegativen Bakterien mit Phenol/Wasser-Emulsionen in der Kälte während weniger Minuten erhält man in der wäßrigen Phase die somatischen Glykoproteide der Bakterien (hauptsächlich 0-Antigene) in praktisch quantitativer Ausbeute. Nach Extraktion der Bakterien mit erwärmten, homogenen Phenol/Wasser-Mischungen und Trennen der Phasen in der Kälte finden sich in der wäßrigen Phase die proteinfreien Polysaccharide neben Nucleinsäuren. Einige chemische und immunologische Eigenschaften der nach den beiden Verfahren dargestellten Glykoproteide und Polysaccharide werden beschrieben.

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Quantitative estimation of proteins by electrophoresis in agarose gel containing antibodies

1966-04-01

Carl‐Bertil Laurell

Glycosylation and the Immune System

2001-03-23

Pauline M. Rudd , Tim Elliott , Peter Cresswell +2 more

Almost all of the key molecules involved in the innate and adaptive immune response are glycoproteins. In the cellular immune system, specific glycoforms are involved in the folding, quality control, … Almost all of the key molecules involved in the innate and adaptive immune response are glycoproteins. In the cellular immune system, specific glycoforms are involved in the folding, quality control, and assembly of peptide-loaded major histocompatibility complex (MHC) antigens and the T cell receptor complex. Although some glycopeptide antigens are presented by the MHC, the generation of peptide antigens from glycoproteins may require enzymatic removal of sugars before the protein can be cleaved. Oligosaccharides attached to glycoproteins in the junction between T cells and antigen-presenting cells help to orient binding faces, provide protease protection, and restrict nonspecific lateral protein-protein interactions. In the humoral immune system, all of the immunoglobulins and most of the complement components are glycosylated. Although a major function for sugars is to contribute to the stability of the proteins to which they are attached, specific glycoforms are involved in recognition events. For example, in rheumatoid arthritis, an autoimmune disease, agalactosylated glycoforms of aggregated immunoglobulin G may induce association with the mannose-binding lectin and contribute to the pathology.

GEFs and GAPs: Critical Elements in the Control of Small G Proteins

2007-06-01

Johannes L. Bos , Holger Rehmann , Alfred Wittinghofer

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Cycling of O-linked β-N-acetylglucosamine on nucleocytoplasmic proteins

2007-04-01

Gerald W. Hart , Michael P. Housley , Chad Slawson

DEMONSTRATION OF TUMOR-SPECIFIC ANTIGENS IN HUMAN COLONIC CARCINOMATA BY IMMUNOLOGICAL TOLERANCE AND ABSORPTION TECHNIQUES

1965-03-01

Phil Gold , Samuel O. Freedman

Two methods were used to demonstrate the presence of tumor-specific antigens in adenocarcinomata of the human colon: (a) rabbits were immunized with extracts of pooled colonic carcinomata, and the antitumor … Two methods were used to demonstrate the presence of tumor-specific antigens in adenocarcinomata of the human colon: (a) rabbits were immunized with extracts of pooled colonic carcinomata, and the antitumor antisera thus produced were absorbed with a pooled extract of normal human colon and with human blood components; (b) newborn rabbits were made immunologically tolerant to normal colonic tissue at birth, and were then immunized with pooled tumor material in adult life. Normal and tumor tissues were obtained from the same human donors in order to avoid misinterpretation of results due to individual-specific antigenic differences. The antisera prepared by both methods were tested against normal and tumor antigens by the techniques of agar gel diffusion, immunoelectrophoresis, hemagglutination, PCA, and immunofluorescence. Distinct antibody activity directed against at least two qualitatively tumor-specific antigens, or antigenic determinants, was detected in the antisera prepared by both methods and at least two additional tumor antigens were detected exclusively in antisera prepared by the tolerance technique. Whether these additional antigens were qualitatively different from normal tissue antigens, or merely present in tumor tissue in higher concentrations than in normal tissue has not as yet been determined. Furthermore, it was shown that the tumor-specific antibodies were not directed against bacterial contaminants or against the unusually high concentrations of fibrin found in many neoplastic tissues. It was concluded from these results that the pooled tumor extracts contained tumor-specific antigens not present in normal colonic tissue. Identical tumor-specific antigens were also demonstrated in a number of individual colonic carcinomata obtained from different human donors.

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On the frequency of protein glycosylation, as deduced from analysis of the SWISS-PROT database

1999-12-17

Rolf Apweiler

Vertebrate protein glycosylation: diversity, synthesis and function

2012-06-22

Kelley W. Moremen , Michael Tiemeyer , Alison V. Nairn

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STUDIES ON ANTIBODY PRODUCTION

1955-07-01

Albert H. Coons , Elizabeth H. Leduc , Jeanne M. Connolly

A method for the specific histochemical demonstration of antibody in cells and parts of cells is described. It consists of carrying out a two stage immunological reaction on frozen sections … A method for the specific histochemical demonstration of antibody in cells and parts of cells is described. It consists of carrying out a two stage immunological reaction on frozen sections of tissues: (a) allowing reaction between antibody in the tissue and dilute antigen applied in vitro, and (b) the detection of those areas where this antigen has been specifically absorbed by means of a precipitin reaction carried out with fluorescein-labelled antibody. Examination under the fluorescence microscope reveals the yellow-green fluorescence of fluorescein over those areas where a precipitate has formed. A study of the hyperimmune rabbit on the first few days after the last of a series of intravenous antigen injections reveals that antibody against human gamma-globulin or ovalbumin is present in groups of plasma cells in the red pulp of the spleen, the medullary areas of lymph nodes, the submucosa of the ileum, and the portal connective tissue of the liver. Because of extensive non-specific reactions, the bone marrow could not be examined. Small amounts of antibody were occasionally visible in cells in the lymphoid follicles of the spleen and lymph nodes, so that a minor contribution by lymphocytes to antibody synthesis cannot be excluded.

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Glycosylation in Cellular Mechanisms of Health and Disease

2006-09-01

Kazuaki Ohtsubo , Jamey D. Marth

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Intracellular Functions of N-Linked Glycans

2001-03-23

Ari Helenius , and Markus Aebi

N-linked oligosaccharides arise when blocks of 14 sugars are added cotranslationally to newly synthesized polypeptides in the endoplasmic reticulum (ER). These glycans are then subjected to extensive modification as the … N-linked oligosaccharides arise when blocks of 14 sugars are added cotranslationally to newly synthesized polypeptides in the endoplasmic reticulum (ER). These glycans are then subjected to extensive modification as the glycoproteins mature and move through the ER via the Golgi complex to their final destinations inside and outside the cell. In the ER and in the early secretory pathway, where the repertoire of oligosaccharide structures is still rather small, the glycans play a pivotal role in protein folding, oligomerization, quality control, sorting, and transport. They are used as universal “tags” that allow specific lectins and modifying enzymes to establish order among the diversity of maturing glycoproteins. In the Golgi complex, the glycans acquire more complex structures and a new set of functions. The division of synthesis and processing between the ER and the Golgi complex represents an evolutionary adaptation that allows efficient exploitation of the potential of oligosaccharides.

Continuous cultures of fused cells secreting antibody of predefined specificity

1975-08-01

Georges Köhler , César Milstein

Carbohydrate analysis by a phenol–sulfuric acid method in microplate format

2004-12-30

Tatsuya Masuko , Akio Minami , Norimasa Iwasaki +3 more

Lectins: Carbohydrate-Specific Proteins That Mediate Cellular Recognition

1998-03-19

Halina Lis , Nathan Sharon

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTLectins: Carbohydrate-Specific Proteins That Mediate Cellular Recognition†Halina Lis and Nathan SharonView Author Information Department of Membrane Research and Biophysics, The Weizmann Institute of Science, Rehovot 76100, Israel … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTLectins: Carbohydrate-Specific Proteins That Mediate Cellular Recognition†Halina Lis and Nathan SharonView Author Information Department of Membrane Research and Biophysics, The Weizmann Institute of Science, Rehovot 76100, Israel Cite this: Chem. Rev. 1998, 98, 2, 637–674Publication Date (Web):March 19, 1998Publication History Received25 July 1997Revised20 January 1998Published online19 March 1998Published inissue 1 April 1998https://pubs.acs.org/doi/10.1021/cr940413ghttps://doi.org/10.1021/cr940413gresearch-articleACS PublicationsCopyright © 1998 American Chemical SocietyRequest reuse permissionsArticle Views8096Altmetric-Citations1460LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Carbohydrates,Ligands,Monomers,Oligosaccharides,Peptides and proteins Get e-Alerts

Lectins: Cell-Agglutinating and Sugar-Specific Proteins

1972-09-15

Nathan Sharon , Halina Lis

Precision mapping of the human O-GalNAc glycoproteome through SimpleCell technology

2013-04-12

Catharina Steentoft , Sergey Y. Vakhrushev , Hiren J. Joshi +7 more

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Glycans in cancer and inflammation — potential for therapeutics and diagnostics

2005-06-01

Danielle H. Dube , Carolyn R. Bertozzi

Early lymphocyte expansion is severely impaired in interleukin 7 receptor-deficient mice.

1994-11-01

Jacques J. Peschon , Philip Morrissey , Kenneth H. Grabstein +7 more

Interleukin 7 (IL-7) stimulates the proliferation of B cell progenitors, thymocytes, and mature T cells through an interaction with a high affinity receptor (IL-7R) belonging to the hematopoietin receptor superfamily. … Interleukin 7 (IL-7) stimulates the proliferation of B cell progenitors, thymocytes, and mature T cells through an interaction with a high affinity receptor (IL-7R) belonging to the hematopoietin receptor superfamily. We have further addressed the role of IL-7 and its receptor during B and T cell development by generating mice genetically deficient in IL-7R. Mutant mice display a profound reduction in thymic and peripheral lymphoid cellularity. Analyses of lymphoid progenitor populations in IL-7R-deficient mice define precisely those developmental stages affected by the mutation and reveal a critical role for IL-7R during early lymphoid development. Significantly, these studies indicate that the phase of thymocyte expansion occurring before the onset of T cell receptor gene rearrangement is critically dependent upon, and mediated by the high affinity receptor for IL-7.

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The Carbohydrate-Active EnZymes database (CAZy): an expert resource for Glycogenomics

2008-10-06

Brandi L. Cantarel , P. M. Coutinho , Corinne Rancurel +3 more

The Carbohydrate-Active Enzyme (CAZy) database is a knowledge-based resource specialized in the enzymes that build and breakdown complex carbohydrates and glycoconjugates.As of September 2008, the database describes the present knowledge … The Carbohydrate-Active Enzyme (CAZy) database is a knowledge-based resource specialized in the enzymes that build and breakdown complex carbohydrates and glycoconjugates.As of September 2008, the database describes the present knowledge on 113 glycoside hydrolase, 91 glycosyltransferase, 19 polysaccharide lyase, 15 carbohydrate esterase and 52 carbohydrate-binding module families.These families are created based on experimentally characterized proteins and are populated by sequences from public databases with significant similarity.Protein biochemical information is continuously curated based on the available literature and structural information.Over 6400 proteins have assigned EC numbers and 700 proteins have a PDB structure.The classification (i) reflects the structural features of these enzymes better than their sole substrate specificity, (ii) helps to reveal the evolutionary relationships between these enzymes and (iii) provides a convenient framework to understand mechanistic properties.This resource has been available for over 10 years to the scientific community, contributing to information dissemination and providing a transversal nomenclature to glycobiologists.More recently, this resource has been used to improve the quality of functional predictions of a number genome projects by providing expert annotation.

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Comparison of the predicted and observed secondary structure of T4 phage lysozyme

1975-10-01

Brian W. Matthews

Glycosyltransferases: Structures, Functions, and Mechanisms

2007-02-09

Luke L. Lairson , Bernard Henrissat , G.J. Davies +1 more

Glycosyltransferases catalyze glycosidic bond formation using sugar donors containing a nucleoside phosphate or a lipid phosphate leaving group. Only two structural folds, GT-A and GT-B, have been identified for the … Glycosyltransferases catalyze glycosidic bond formation using sugar donors containing a nucleoside phosphate or a lipid phosphate leaving group. Only two structural folds, GT-A and GT-B, have been identified for the nucleotide sugar-dependent enzymes, but other folds are now appearing for the soluble domains of lipid phosphosugar-dependent glycosyl transferases. Structural and kinetic studies have provided new insights. Inverting glycosyltransferases utilize a direct displacement S(N)2-like mechanism involving an enzymatic base catalyst. Leaving group departure in GT-A fold enzymes is typically facilitated via a coordinated divalent cation, whereas GT-B fold enzymes instead use positively charged side chains and/or hydroxyls and helix dipoles. The mechanism of retaining glycosyltransferases is less clear. The expected two-step double-displacement mechanism is rendered less likely by the lack of conserved architecture in the region where a catalytic nucleophile would be expected. A mechanism involving a short-lived oxocarbenium ion intermediate now seems the most likely, with the leaving phosphate serving as the base.

Glycosphingolipids in Cellular Interaction, Differentiation, and Oncogenesis

1981-06-01

Sen‐itiroh Hakomori

The Hippo pathway was initially discovered in Drosophila melanogaster as a key regulator of tissue growth. It is an evolutionarily conserved signaling cascade regulating numerous biological processes, including cell growth … The Hippo pathway was initially discovered in Drosophila melanogaster as a key regulator of tissue growth. It is an evolutionarily conserved signaling cascade regulating numerous biological processes, including cell growth and fate decision, organ size ...Read More

Protein glycosylation: nature, distribution, enzymatic formation, and disease implications of glycopeptide bonds

2002-04-01

Robert G. Spiro

Formation of the sugar–amino acid linkage is a crucial event in the biosynthesis of the carbohydrate units of glycoproteins. It sets into motion a complex series of posttranslational enzymatic steps … Formation of the sugar–amino acid linkage is a crucial event in the biosynthesis of the carbohydrate units of glycoproteins. It sets into motion a complex series of posttranslational enzymatic steps that lead to the formation of a host of protein-bound oligosaccharides with diverse biological functions. These reactions occur throughout the entire phylogenetic spectrum, ranging from archaea and eubacteria to eukaryotes. It is the aim of this review to describe the glycopeptide linkages that have been found to date and specify their presence on well-characterized glycoproteins. A survey is also made of the enzymes involved in the formation of the various glycopeptide bonds as well as the site of their intracellular action and their affinity for particular peptide domains is evaluated. This examination indicates that 13 different monosaccharides and 8 amino acids are involved in glycoprotein linkages leading to a total of at least 41 bonds, if the anomeric configurations, the phosphoglycosyl linkages, as well as the GPI (glycophosphatidylinositol) phosphoethanolamine bridge are also considered. These bonds represent the products of N- and O-glycosylation, C-mannosylation, phosphoglycation, and glypiation. Currently at least 16 enzymes involved in their formation have been identified and in many cases cloned. Their intracellular site of action varies and includes the endoplasmic reticulum, Golgi apparatus, cytosol, and nucleus. With the exception of the Asn-linked carbohydrate and the GPI anchor, which are transferred to the polypeptide en bloc, the sugar–amino acid linkages are formed by the enzymatic transfer of an activated monosaccharide directly to the protein. This review also deals briefly with glycosidases, which are involved in physiologically important cleavages of glycopeptide bonds in higher organisms, and with a number of human disease states in which defects in enzymatic transfer of saccharides to protein have been implicated.

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Essentials of glycobiology

2009-09-01

G. Ya. Wiederschain

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Interleukin 4 potently enhances murine macrophage mannose receptor activity: a marker of alternative immunologic macrophage activation.

1992-07-01

Michael Stein , Satish Keshav , Nicholas Harris +1 more

Expression of the macrophage mannose receptor is inhibited by interferon gamma (IFN-gamma), a T helper type 1 (Th-1)-derived lymphokine. Interleukin 4 (IL-4), a Th-2 lymphocyte product, upregulates major histocompatibility class … Expression of the macrophage mannose receptor is inhibited by interferon gamma (IFN-gamma), a T helper type 1 (Th-1)-derived lymphokine. Interleukin 4 (IL-4), a Th-2 lymphocyte product, upregulates major histocompatibility class II antigen expression but inhibits inflammatory cytokine production by macrophages. We have studied the effect of IL-4 on expression of the macrophage mannose receptor (MMR) by elicited peritoneal macrophages. We found that recombinant murine IL-4 enhances MMR surface expression (10-fold) and activity (15-fold), as measured by the respective binding and degradation of 125I-mannose-bovine serum albumin. Polymerase chain reaction analysis of cDNAs from purified primary macrophage populations revealed that MMR, but not lysozyme or tumor necrosis factor alpha, mRNA levels were markedly increased by IL-4. The above effects were associated with morphologic changes. These data establish IL-4 as a potent and selective enhancer of murine MMR activity in vitro. IL-4 induces inflammatory macrophages to adopt an alternative activation phenotype, distinct from that induced by IFN-gamma, characterized by a high capacity for endocytic clearance of mannosylated ligands, enhanced (albeit restricted) MHC class II antigen expression, and reduced proinflammatory cytokine secretion.

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Identification and quantification of N-linked glycoproteins using hydrazide chemistry, stable isotope labeling and mass spectrometry

2003-05-16

Hui Zhang , Xiaojun Li , Daniel Martin +1 more

Biological roles of oligosaccharides: all of the theories are correct

1993-04-01

Ajit Varki

Many different theories have been advanced concerning the biological roles of the oligosaccharide units of individual classes of glycoconjugates. Analysis of the evidence indicates that while all of these theories … Many different theories have been advanced concerning the biological roles of the oligosaccharide units of individual classes of glycoconjugates. Analysis of the evidence indicates that while all of these theories are correct, exceptions to each can also be found. The biological roles of oligosaccharides appear to span the spectrum from those that are trivial, to those that are crucial for the development, growth, function or survival of an organism. Some general principles emerge. First, it is difficult to predict a priori the functions a given oligosaccharide on a given glycoconjugate might be mediating, or their relative importance to the organism. Second, the same oligosaccharide sequence may mediate different functions at different locations within the same organism, or at different times in its ontogeny or life cycle. Third, the more specific and crucial biological roles of oligosaccharides are often mediated by unusual oligosaccharide sequences, unusual presentations of common terminal sequences, or by further modifications of the sugars themselves. However, such oligosaccharide sequences are also more likely to be targets for recognition by pathogenic toxins and microorganisms. As such, they are subject to more intra- and inter-species variation because of ongoing host—pathogen interactions during evolution. In the final analysis, the only common features of the varied functions of oligosaccharides are that they either mediate ‘specific recognition’ events or that they provide ‘modulation’ of biological processes. In so doing, they generate much of the functional diversity required for the development and differentiation of complex organisms, and for their interactions with other organisms in the environment.

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Large-scale characterization of HeLa cell nuclear phosphoproteins

2004-08-09

Sean A. Beausoleil , Mark P. Jedrychowski , Daniel Schwartz +6 more

Determining the site of a regulatory phosphorylation event is often essential for elucidating specific kinase–substrate relationships, providing a handle for understanding essential signaling pathways and ultimately allowing insights into numerous … Determining the site of a regulatory phosphorylation event is often essential for elucidating specific kinase–substrate relationships, providing a handle for understanding essential signaling pathways and ultimately allowing insights into numerous disease pathologies. Despite intense research efforts to elucidate mechanisms of protein phosphorylation regulation, efficient, large-scale identification and characterization of phosphorylation sites remains an unsolved problem. In this report we describe an application of existing technology for the isolation and identification of phosphorylation sites. By using a strategy based on strong cation exchange chromatography, phosphopeptides were enriched from the nuclear fraction of HeLa cell lysate. From 967 proteins, 2,002 phosphorylation sites were determined by tandem MS. This unprecedented large collection of sites permitted a detailed accounting of known and unknown kinase motifs and substrates.

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Lack of Fucose on Human IgG1 N-Linked Oligosaccharide Improves Binding to Human FcγRIII and Antibody-dependent Cellular Toxicity

2002-07-01

Robert L. Shields , Jadine Lai , Rodney G. Keck +5 more

Lec13 cells, a variant Chinese hamster ovary cell line, were used to produce human IgG1 that were deficient in fucose attached to the Asn297-linked carbohydrate but were otherwise similar to … Lec13 cells, a variant Chinese hamster ovary cell line, were used to produce human IgG1 that were deficient in fucose attached to the Asn297-linked carbohydrate but were otherwise similar to that found in IgG1 produced in normal Chinese hamster ovary cell lines and from human serum. Lack of fucose on the IgG1 had no effect on binding to human FcγRI, C1q, or the neonatal Fc receptor. Although no change in affinity was found for the His131 polymorphic form of human FcγRIIA, a slight improvement in binding was evident for FcγRIIB and the Arg131 FcγRIIA polymorphic form. In contrast, binding of the fucose-deficient IgG1 to human FcγRIIIA was improved up to 50-fold. Antibody-dependent cellular cytotoxicity assays using purified peripheral blood monocytes or natural killer cells from several donors showed enhanced cytotoxicity, especially evident at lower antibody concentrations. When combined with an IgG1 Fc protein variant that exhibited enhanced antibody-dependent cellular cytotoxicity, the lack of fucose was synergistic.

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Plaque Formation in Agar by Single Antibody-Producing Cells

1963-04-26

N. K. Jerne , Albert A. Nordin

Distinct plaques, each of which is due to the release of hemolysin by a single antibody-forming cell, are revealed by complement after incubation, in an agar layer, of a mixture … Distinct plaques, each of which is due to the release of hemolysin by a single antibody-forming cell, are revealed by complement after incubation, in an agar layer, of a mixture of sheep red cells and lymphoid cells from a rabbit immunized with sheep red cells.

Roles of N-Linked Glycans in the Endoplasmic Reticulum

2004-06-01

Ari Helenius , Markus Aebi

▪ Abstract From a process involved in cell wall synthesis in archaea and some bacteria, N-linked glycosylation has evolved into the most common covalent protein modification in eukaryotic cells. The … ▪ Abstract From a process involved in cell wall synthesis in archaea and some bacteria, N-linked glycosylation has evolved into the most common covalent protein modification in eukaryotic cells. The sugars are added to nascent proteins as a core oligosaccharide unit, which is then extensively modified by removal and addition of sugar residues in the endoplasmic reticulum (ER) and the Golgi complex. It has become evident that the modifications that take place in the ER reflect a spectrum of functions related to glycoprotein folding, quality control, sorting, degradation, and secretion. The glycans not only promote folding directly by stabilizing polypeptide structures but also indirectly by serving as recognition “tags” that allow glycoproteins to interact with a variety of lectins, glycosidases, and glycosyltranferases. Some of these (such as glucosidases I and II, calnexin, and calreticulin) have a central role in folding and retention, while others (such as α-mannosidases and EDEM) target unsalvageable glycoproteins for ER-associated degradation. Each residue in the core oligosaccharide and each step in the modification program have significance for the fate of newly synthesized glycoproteins.

Mucins in cancer: protection and control of the cell surface

2003-12-18

Michael A. Hollingsworth , Benjamin Swanson

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Protein structure alignment by incremental combinatorial extension (CE) of the optimal path

1998-09-01

Ilya N. Shindyalov , Philip E. Bourne

A new algorithm is reported which builds an alignment between two protein structures. The algorithm involves a combinatorial extension (CE) of an alignment path defined by aligned fragment pairs (AFPs) … A new algorithm is reported which builds an alignment between two protein structures. The algorithm involves a combinatorial extension (CE) of an alignment path defined by aligned fragment pairs (AFPs) rather than the more conventional techniques using dynamic programming and Monte Carlo optimization. AFPs, as the name suggests, are pairs of fragments, one from each protein, which confer structure similarity. AFPs are based on local geometry, rather than global features such as orientation of secondary structures and overall topology. Combinations of AFPs that represent possible continuous alignment paths are selectively extended or discarded thereby leading to a single optimal alignment. The algorithm is fast and accurate in finding an optimal structure alignment and hence suitable for database scanning and detailed analysis of large protein families. The method has been tested and compared with results from Dali and VAST using a representative sample of similar structures. Several new structural similarities not detected by these other methods are reported. Specific one-on-one alignments and searches against all structures as found in the Protein Data Bank (PDB) can be performed via the Web at http://cl.sdsc.edu/ce.html.

Glycobiology: Toward Understanding the Function of Sugars

1996-01-01

Raymond A. Dwek

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTGlycobiology: Toward Understanding the Function of SugarsRaymond A. DwekView Author Information The Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTGlycobiology: Toward Understanding the Function of SugarsRaymond A. DwekView Author Information The Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK Cite this: Chem. Rev. 1996, 96, 2, 683–720Publication Date (Web):March 28, 1996Publication History Received20 July 1995Revised28 October 1995Published online28 March 1996Published inissue 1 January 1996https://pubs.acs.org/doi/10.1021/cr940283bhttps://doi.org/10.1021/cr940283bresearch-articleACS PublicationsRequest reuse permissionsArticle Views12859Altmetric-Citations2459LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Carbohydrates,Chemical biology,Oligosaccharides,Peptides and proteins,Post-translational modification Get e-Alerts

10 Years of GWAS Discovery: Biology, Function, and Translation

2017-07-01

Peter M. Visscher , Naomi R. Wray , Qian Zhang +4 more

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dbCAN2: a meta server for automated carbohydrate-active enzyme annotation

2018-05-04

Han Zhang , Tanner Yohe , Le Huang +6 more

Complex carbohydrates of plants are the main food sources of animals and microbes, and serve as promising renewable feedstock for biofuel and biomaterial production. Carbohydrate active enzymes (CAZymes) are the … Complex carbohydrates of plants are the main food sources of animals and microbes, and serve as promising renewable feedstock for biofuel and biomaterial production. Carbohydrate active enzymes (CAZymes) are the most important enzymes for complex carbohydrate metabolism. With an increasing number of plant and plant-associated microbial genomes and metagenomes being sequenced, there is an urgent need of automatic tools for genomic data mining of CAZymes. We developed the dbCAN web server in 2012 to provide a public service for automated CAZyme annotation for newly sequenced genomes. Here, dbCAN2 (http://cys.bios.niu.edu/dbCAN2) is presented as an updated meta server, which integrates three state-of-the-art tools for CAZome (all CAZymes of a genome) annotation: (i) HMMER search against the dbCAN HMM (hidden Markov model) database; (ii) DIAMOND search against the CAZy pre-annotated CAZyme sequence database and (iii) Hotpep search against the conserved CAZyme short peptide database. Combining the three outputs and removing CAZymes found by only one tool can significantly improve the CAZome annotation accuracy. In addition, dbCAN2 now also accepts nucleotide sequence submission, and offers the service to predict physically linked CAZyme gene clusters (CGCs), which will be a very useful online tool for identifying putative polysaccharide utilization loci (PULs) in microbial genomes or metagenomes.

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Glycosylation in health and disease

2019-03-11

Colin Reily , Tyler J. Stewart , Matthew B. Renfrow +1 more

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The carbohydrate-active enzyme database: functions and literature

2021-10-15

Élodie Drula , Marie-Line Garron , S. Doğan +3 more

Thirty years have elapsed since the emergence of the classification of carbohydrate-active enzymes in sequence-based families that became the CAZy database over 20 years ago, freely available for browsing and … Thirty years have elapsed since the emergence of the classification of carbohydrate-active enzymes in sequence-based families that became the CAZy database over 20 years ago, freely available for browsing and download at www.cazy.org. In the era of large scale sequencing and high-throughput Biology, it is important to examine the position of this specialist database that is deeply rooted in human curation. The three primary tasks of the CAZy curators are (i) to maintain and update the family classification of this class of enzymes, (ii) to classify sequences newly released by GenBank and the Protein Data Bank and (iii) to capture and present functional information for each family. The CAZy website is updated once a month. Here we briefly summarize the increase in novel families and the annotations conducted during the last 8 years. We present several important changes that facilitate taxonomic navigation, and allow to download the entirety of the annotations. Most importantly we highlight the considerable amount of work that accompanies the analysis and report of biochemical data from the literature.

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A Compact Method Specialized for Full Analysis of the Glycan Composition of Jellyfish Mucin Using Limited Degradation Followed by High-Resolution Mass Spectrometry

2025-06-24

Shiori Kaise , Minami Sugiyama , Shinra Tanaka +3 more | Journal of the American Society for Mass Spectrometry

A compact and specialized method for analyzing the O-glycan composition of jellyfish mucin (Q-mucin) has been newly developed. Q-mucin was analyzed using high-resolution mass spectrometry (HRMS) with electrospray ionization (ESI), … A compact and specialized method for analyzing the O-glycan composition of jellyfish mucin (Q-mucin) has been newly developed. Q-mucin was analyzed using high-resolution mass spectrometry (HRMS) with electrospray ionization (ESI), combined with limited degradation (LD) by endoprotease Glu-C. Direct analysis of the solution after enzymolysis caused unwanted dissociation of glycan adducts from tandem repeats (TRs). However, the introduction of HPLC prior to ESI, utilizing a reverse-phase column with an aqueous solution of formic acid and acetonitrile as the mobile phase, successfully minimized the source dissociation of many glycan adducts from TRs. As a result, we established a rapid and cost-effective protocol for analyzing the O-glycans in Q-mucin over a wide dynamic range. Q-mucin contains two types of TRs that are commonly shared by a large number of jellyfish species. However, the residual challenge lies in understanding the O-glycan composition, which varies depending on species and ecological factors. For systematic studies across a vast number of species, the newly developed protocol, which does not rely on complex analytical algorithms, proves highly suitable. Given its superior time efficiency and accuracy compared to large-scale mass analysis programs designed for general use, we propose that the development of purpose-oriented methods holds significant value for specialized studies using mass spectrometry.

Biodistribution of a Mucin 4-Selective Monoclonal Antibody: Defining a Potential Therapeutic Agent Against Pancreatic Cancer

2025-06-24

Achyut Dahal , Jerome Schlomer , Laura Bassel +2 more | International Journal of Molecular Sciences

We have previously reported on a novel monoclonal antibody (mAb) we designated F5, which was raised against a glycopeptide derived from the tandem repeat (TR) region of Mucin-4 (MUC4), a … We have previously reported on a novel monoclonal antibody (mAb) we designated F5, which was raised against a glycopeptide derived from the tandem repeat (TR) region of Mucin-4 (MUC4), a heavily O-glycosylated protein that is overexpressed in many pancreatic cancer cells. This mAb was highly specific for the MUC4 glycopeptide antigen in glycan microarrays, ELISA and SPR assays, selectively stained tissue derived from advanced-stage tumors, and bound MUC4+ tumor cells in flow cytometry assays. The mAb was also unique in that it did not cross-react with other commercial anti-MUC4 mAbs that were raised in a similar but non-glycosylated TR sequence. Here we describe the selective conjugation of a novel near-infrared dye to this mAb and in vivo biodistribution of this labeled mAb to various MUC4-expressing tumors in mice. The labeled mAb were selectively distributed to both cell-derived xenograft (CDX) flank tumors and patient-derived xenograft (PDX) tumors that expressed MUC4 compared to those that were MUC4-negative. Organ distribution analysis showed high uptake in MUC4+ relative to MUC4− tumors. These results suggest that mAb F5 may be used to develop MUC4-targeted, passive antibody-based immunotherapies against Pancreatic Ductal Adenocarcinomas (PDACs) which are notorious for being refractory to many chemo- and radiotherapies

Common Gene Networks Orchestrate Organelle Architecture and Inter-Organelle Metabolic Flows for Mucin Production in High Endothelial and Goblet Cells

2025-06-24

Yuhan Bi , Kevin Brulois , Aiman Ayesha +7 more | bioRxiv (Cold Spring Harbor Laboratory)

High endothelial cells (HECs) and intestinal goblet cells (GCs) are highly specialized through organelle expansion and metabolism for production of sulfated mucins essential for lymphocyte homing and mucosal defense, respectively. … High endothelial cells (HECs) and intestinal goblet cells (GCs) are highly specialized through organelle expansion and metabolism for production of sulfated mucins essential for lymphocyte homing and mucosal defense, respectively. How these cells coordinate organelle architecture and biosynthetic pathways to support such demands remains poorly understood. Here, we show at single-cell resolution that HECs rely on gene regulatory networks driven by IRE1α-XBP1 and CREB3L1/2 transcription factors. These networks upregulate enzymes and transporters that control inter-organelle metabolic fluxes for the step-wise assembly of sulfated O-glycan synthesis, while scaling the endoplasmic reticulum (ER) and Golgi apparatus, reinforcing cargo trafficking and organizing sequential glycosyltransferase deployment. Genetic and pharmacological perturbations show that these transcriptional circuits sustain lymph node HEC morphology and function in lymphocyte homing, and drive ectopic induction of HEV during inflammation. Parallel transcriptional networks operate in GCs. Together, our findings define a conserved regulatory logic that integrates metabolic pathways and organelle architecture to enable committed sulfo-mucin cell specialization across distinct tissue contexts.

Harnessing magnetic cross-linked cell aggregates (CLCAs) for cost-effective preparation of Konjac mannan-oligosaccharide

2025-06-24

Baoyu Cui , Haiqiang Lu , Xue Liu +2 more | Microbial Cell Factories

Konjac mannan oligosaccharides (KMOS) are currently popular in food additives for their health benefits. However, the simple and efficient preparation of KMOS is still a challenge. In this study, A … Konjac mannan oligosaccharides (KMOS) are currently popular in food additives for their health benefits. However, the simple and efficient preparation of KMOS is still a challenge. In this study, A novel gene encoding β-mannanase (CsMan134) from Cellvibrio sp. KY-GH-1 was displayed on the surface of E. coli cells. Subsequently, E.coli cells (3 g/L) expressing the mannanase CsMan134 were immobilized using 8% (w/v) polyvinyl alcohol, 3% (w/v) sodium alginate, and 3.5% (w/v) Fe₃O₄ to construct magnetic cross-linked cell aggregates (mag-CLCAs). The mannanase CsMan134 demonstrated the highest catalytic efficiency towards konjac mannan compared to other mannans. Compared to free enzyme, the mag-CLCAs exhibited enhanced enzymatic activity across a range of temperatures and pH levels. Furthermore, the mag-CLCAs showed improved thermal stability, retaining over 80% of its initial activity after heating at 50 °C for 180 min, whereas the free enzyme retained only 50% of its residual activity. Scanning electron microscopy (SEM) and vibrating sample magnetometry (VSM) analyses indicated that the mag-CLCAs also maintained good operational stability, retaining more than 75% of their initial activity over five cycles. The mag-CLCAs were effective in converting konjac mannan into a substantial amount of oligosaccharides with a degree of polymerization (DP) of 2-4. In conclusion, the mag-CLCAs represent a valuable, efficient, and cost-effective biocatalyst for the production of KMOS for industrial applications.

Patterns of sialyl-Lewis X expression predict gastric histopathology

2025-06-23

Nancy Vargas , Andrés Quiroga , João Chaves +5 more | Diagnostic Pathology

Structure of human glycoprotein 2 reveals mechanisms underlying filament formation and adaption to proteolytic environment in the digestive tract

2025-06-23

Jianting Han , Meinai Song , Yijia Cheng +3 more | PLoS Biology

Glycoprotein 2 (GP2) and Uromodulin (UMOD) are considered as paralogs that share high sequence similarity and have similar antibacterial functions. UMOD are abundant as filaments in the urinary tract, and … Glycoprotein 2 (GP2) and Uromodulin (UMOD) are considered as paralogs that share high sequence similarity and have similar antibacterial functions. UMOD are abundant as filaments in the urinary tract, and a high-mannose N-glycosylation site located on the N-terminal region protruding from UMOD filament core (referred to as branch) acts as an adhesion antagonist against pathogenic bacterial infections. The antibacterial function of UMOD can be eliminated by proteases, as the UMOD branch is susceptible to proteolytic activity. GP2 is expressed in the pancreas and secreted into the digestive tract. Whether GP2 executes its function in filament form and how it remains functional in the protease-enriched digestive tract is unclear. In this study, we extract GP2 filaments from surgically excised human pancreas and determined their cryo-EM structure. Our structure analysis unveiled that GP2 forms filaments with its ZP modules, composing the ZPN and ZPC domains along with a linker that connects these two domains. The N-terminal region (branch) of GP2 does not constitute the filament core and appears flexible in the cryo-EM structure. Our biochemical experiments suggested that although the GP2 branch is also protease-susceptible, additional high-mannose N-glycans were identified on the protease-resistant GP2 filament core. Consequently, the branch-free GP2 filaments retain their binding ability to the bacterial adhesin FimH, ensuring GP2's antibacterial function unaffected in the proteolytic environment. Our study provides the first experimental evidence of GP2 filament formation and reveals the molecular mechanisms underlying GP2's adaptation to a different environment compared to UMOD.

A simple and highly efficient method for enriching and separating glycoproteins in complex biological samples using polyethyleneimine- and boric acid-grafted metal–organic frameworks on magnetic nanospheres

2025-06-23

Hang Gong , Ruirui Hu , Feng Chen +4 more | Microchimica Acta

Physicochemical properties of micromycetes Alternaria alternate 4 lectin

2025-06-21

Zinurov M.R , Zinurova E.E , Bagaeva T.V +1 more | GSC Advanced Research and Reviews

The physicochemical properties of the lectin of the lower fungus, micromycetes Alternaria alternate 4 have been studied. It was found that the lectin of the micromycetes Alternaria alternate 4 is … The physicochemical properties of the lectin of the lower fungus, micromycetes Alternaria alternate 4 have been studied. It was found that the lectin of the micromycetes Alternaria alternate 4 is stable over a wide range of temperatures and pH values (5-70oC and pH 6.0-9.0). The greatest activity of lectin was observed at a temperature of 5-50 °C and a pH of 6.5-8.5. The increased activity of Alternaria alternate 4 lectin was facilitated by the presence of divalent Ca2+, Mn2+, and Zn2+ ions in the reaction mixture, which indicates that Alternaria alternate 4 lectin is a metal-dependent glycoprotein. Alternaria alternate 4 lectin had the ability to bind simple carbohydrates. The activity of Alternaria alternate 4 lectin was inhibited to a greater extent by galactose, which indicates that Alternaria alternate 4 lectin belongs to the group of galactose-binding lectins.

Glycolipid recognition and binding by Siglec-6 hinges on interactions with the cell membrane

2025-06-21

Silvia D’Andrea , Edward N. Schmidt , Duong T. Bui +6 more | bioRxiv (Cold Spring Harbor Laboratory)

Sialic acid-binding immunoglobulin-type lectins (Siglecs) regulate immune response through interactions with sialylated glycan epitopes on glycoproteins and glycolipids. Human Siglecs count 14 unique proteins allocated to two subsets; group 1 … Sialic acid-binding immunoglobulin-type lectins (Siglecs) regulate immune response through interactions with sialylated glycan epitopes on glycoproteins and glycolipids. Human Siglecs count 14 unique proteins allocated to two subsets; group 1 includes four evolutionarily conserved proteins with clear orthologues in all mammals with low sequence similarity and group 2 includes ten rapidly evolving proteins with high sequence similarity and species specificity. In all Siglecs, the recognition and binding of the sialic acid on the glycan target involves a conserved, or canonical, Arg residue. Yet, for a subset of human Siglecs, namely MAG, Siglec-6, and Siglec-11, this Arg appears not to be essential, suggesting that a different binding mechanism may be at play. In this work, we used all-atom molecular dynamics (MD) simulations, binding assays, and mutagenesis to investigate the structural, mechanistic and energetic details of the binding of Siglec-6 to monosialylated gangliosides. Our results show that Siglec-6 relies only partially on its conserved Arg (Arg122) for recognition of membrane-bound gangliosides and that it supplements its binding free energy through interactions with the phospholipids in the membrane surrounding the target epitope. We identified residues Lys126 and Trp127 as key players in this unique membrane interaction, and we confirmed by mutagenesis assays that the loss of these residues abrogates binding. These results provide a step-change in our understanding of the diversification of human Siglecs across group 2, where different members likely evolved as molecular precision tools, to bind specific sialosides by adapting their structure to recognize not only the epitope, but also the biological environment in which it is found.

Synthesis of Azide-Labeled β-Lactosylceramide Analogs Containing Different Lipid Chains as Useful Glycosphingolipid Probes

2025-06-20

Basant Mohamed , Rajendra Rohokale , Xin Yan +4 more | Molecules

β-Lactosylceramide (β-LacCer) is not only a key intermediate in the biosynthesis of complex glycosphingolipids (GSLs) but also an important regulator of many biological processes. To facilitate the investigation of β-LacCer … β-Lactosylceramide (β-LacCer) is not only a key intermediate in the biosynthesis of complex glycosphingolipids (GSLs) but also an important regulator of many biological processes. To facilitate the investigation of β-LacCer and other GSLs, a series of β-LacCer analogs with an azido group at the 6-C-position of the D-galactose in lactose and varied forms of the ceramide moiety were synthesized from commercially available lactose in sixteen linear steps by a versatile and diversity-oriented strategy, which engaged lipid remodeling and glycan functionalization at the final stage. These azide-labeled β-LacCer analogs are flexible and universal platforms that are suitable for further functionalization with other molecular tags via straightforward and biocompatible click chemistry, thereby paving the way for their application to various biological studies.

N-acetylglucosaminyltransferase V attenuates myocardial infarction by mediating the insulin-like growth factor 1 receptor signaling pathway

2025-06-20

Tianqi Chang , Yinzi Jin , Chenyu Fan +6 more | Journal of Translational Internal Medicine

Abstract Background and Objectives N-glycosylation, a crucial post-translational modification, is well-recognized for its pivotal role in cardiovascular functions. N-acetylglucosaminyltransferase V (GnT-V) is one of the major glycosyltransferases that determine the … Abstract Background and Objectives N-glycosylation, a crucial post-translational modification, is well-recognized for its pivotal role in cardiovascular functions. N-acetylglucosaminyltransferase V (GnT-V) is one of the major glycosyltransferases that determine the complexity of N-glycans in N-glycosylation modification. This study aimed to explore the role of GnT-V in myocardial infarction (MI). Methods Proteomics and N-glycoproteomic analysis were performed on myocardial tissues for the N-glycosylation profile after MI. Adeno-associated virus (AAV) with a mouse cTnT promoter was utilized to induce overexpression of GnT-V in the heart for the role of GnT-V in MI. Echocardiography and histological analysis were used to evaluate the effect of GnT-V on MI. For the potential mechanisms of GnT-V, proteomic analysis was performed on cardiomyocytes that were subjected to GnT-V overexpression and hypoxic stress. The results were validated by western blot, lectin blot and immunoprecipitation assays, and confirmed with PNGase F and tunicamycin treatment. Results N-glycosylation of protein was significantly reduced after MI, which could be related to a decrease in the expression levels of GnT-V and its target glycans. Targeted GnT-V overexpression in the heart by using AAV improved cardiac function and reduced the infarct size after MI. Further, proteomics analysis of cardiomyocytes revealed that insulin-like growth factor-binding protein 3 (IGFBP3) was targeted by GnT-V and induced degradation through the lysosome pathway. Consequently, the insulin-like growth factor 1 receptor (IGF1R) signaling pathway was activated through overexpression of GnT-V. Conclusion Our findings suggest that promoting the IGF1R signaling cascades by regulating the N-glycosylation of certain proteins in the signaling pathway, especially through GnT-V, may act as a promising strategy for treating MI.

Profiling of Permethylated Mucin O-glycans Using Matrix-assisted Laser Desorption/Ionization Time-of-flight Mass Spectrometry

2025-06-20

Dimitrios Latousakis , Nathalie Juge | Journal of Visualized Experiments

Targeting gangliosides to treat Alzheimer’s and Parkinson’s diseases: A disruptive approach with the first-in-class peptide AmyP53

2025-06-19

Jacques Fantini , Nouara Yahi | Neural Regeneration Research

An Integrative Approach to Develop and Characterise Antibodies Against the Cancer Associated Antigen Sialyl Lewis A (CA 19-9)

2025-06-19

Anika Freitag , Sana Khan Khilji , Ruslan Nedielkov +7 more | bioRxiv (Cold Spring Harbor Laboratory)

Abstract Background Sialyl Lewis A (sLeA), or the CA 19-9 marker, is a tetrasaccharide and a tumour-associated carbohydrate antigen (TACA) overexpressed and abnormally secreted as a serum-borne marker in gastrointestinal … Abstract Background Sialyl Lewis A (sLeA), or the CA 19-9 marker, is a tetrasaccharide and a tumour-associated carbohydrate antigen (TACA) overexpressed and abnormally secreted as a serum-borne marker in gastrointestinal malignancies. CA 19-9 is the best validated and only FDA-approved serologic marker clinically used to monitor recurrence, progression, and therapy efficiency in pancreatic ductal adenocarcinoma (PDAC) patients. Due to its altered expression on cancer cells, sLeA is also an attractive target for antibody development. Although recent clinical trials have demonstrated insufficient efficacy of the fully human anti-sLeA 5B1 (MVT-5873) format as a stand-alone drug or an adjuvant therapy in PDAC [1], its safety profile and unique expression in additional malignancies keep CA 19–9 an attractive TACA. Hence, we set out to explore the use of synthetic sLeA to develop novel monoclonal antibodies (mAbs) with improved sLeA recognition and better efficacy. Methods Two mAbs targeting sLeA were generated through mice immunisation with synthetic sLeA glycoconjugates, synthetic glycan arrays, and hybridoma technology. We then compared the antigen-binding properties of the newly developed mAbs with the widely used mAb 1116-NS-19- 9 via synthetic glycan arrays, immunohistochemistry (IHC), X-ray crystallography, molecular dynamics (MD) simulation, and Saturation Transfer Difference Nuclear Magnetic Resonance (STD NMR) spectroscopy. Results The newly generated mAbs demonstrated improved affinity and specificity for both synthetic and native sLeA, surpassing the performance of the established mAb 1116-NS-19-9. First, synthetic glycan arrays, surface plasmon resonance (SPR), and isothermal titration calorimetry (ITC) assays confirmed superior antigen-binding properties to synthetic sLeA. In particular, the mAb designated GB11 demonstrated markedly enhanced binding to native sLeA ectopically expressed in B16 melanoma cells. To elucidate the structural origin of GB11’s improved antigen binding, we conducted high-resolution mapping of the molecular recognition patterns between sLeA and the different antibodies using X-ray crystallography and STD NMR. These analyses revealed subtle yet critical differences in the glycan engagement and identified key structural features underlying GB11’s enhanced recognition of sLeA. MD simulations further supported these observations, indicating distinct orientations of sLeA within the binding pockets of each mAb. Conclusion Our results suggest better recognition of the sLeA antigen by the newly generated GB11 antibody and provide a detailed high-resolution elucidation of the molecular interactions behind it. Our study may provide a novel tool with improved theranostic properties against sLeA-overexpressing malignancies.

Development of Efficiently Quantitative Analysis Targeting α-Galactosylceramide in FreeStyle 293-F Cells

2025-06-19

Kentaro Iwata , Koji Nishimura , Kanae Otsutomo +2 more | Chemical and Pharmaceutical Bulletin

α-Galactosylceramide (α-GalCer), a synthetic lipid that activates natural killer T cells, has been studied for administration as an active component of artificial adjuvant vector cells (aAVCs) for cancer therapy. A … α-Galactosylceramide (α-GalCer), a synthetic lipid that activates natural killer T cells, has been studied for administration as an active component of artificial adjuvant vector cells (aAVCs) for cancer therapy. A quantification method for α-GalCer content in the cells is essential to ensure the antitumor effect of aAVCs. In this study, a new analytical procedure was established using LC and tandem MS, with a lipid extraction method and internal standard method, and its analytical validation was performed. Furthermore, the procedure was applied to determine α-GalCer content in α-GalCer-loaded model cells, which are the original vector cells in aAVCs.

Putting the brakes on thromboinflammation: Siglec-9 and platelet sialylation as a novel regulatory axis

2025-06-19

Marco Heestermans , Hind Hamzeh‐Cognasse , Fabrice Cognasse | Journal of Thrombosis and Haemostasis

POMT-dependentO-mannosylation regulates integrin β1 maturation viaN-glycan processing

2025-06-18

Shahidul Alam , Sina Ibne Noor , Marcus Hoffmann +4 more | bioRxiv (Cold Spring Harbor Laboratory)

Abstract Protein O -mannosylation is a critical post-translational modification that plays a pivotal role in the function of glycoproteins. The current study investigates the impact of defective protein O -mannosylation, … Abstract Protein O -mannosylation is a critical post-translational modification that plays a pivotal role in the function of glycoproteins. The current study investigates the impact of defective protein O -mannosylation, as seen in POMT-deficient cells, on the maturation and function of integrin β1. We demonstrate that POMT deficiency interconnects with the N -glycosylation pathway, leading to an accumulation of immature oligomannose-type N -glycans and a corresponding decrease in complex-type N -glycan structures. This glycosylation defect is associated with a significant reduction in the mature form of integrin β1 on the cell surface, which is crucial for integrin-mediated signaling and cell adhesion. Most interestingly, the downregulation of the α-mannosidase MAN1B1 in POMT-deficient cells contributes to the impaired N -glycosylation and trafficking of integrin β1. Notably, the overexpression of MAN1B1 rescues the integrin β1 maturation defect, highlighting the interconnection between protein O -mannosylation and N -glycosylation pathways. Our findings significantly contribute to the understanding of the molecular mechanisms underlying POMT-related disorders and provide novel insights that could guide future research and therapeutic strategies.

Chemical synthesis uncovers the significant impact of natural glycosylation on islet amyloid polypeptide aggregation

2025-06-18

Yaohao Li , Wenqiang Liu , Ruihan Wang +7 more | Science Advances

Protein and peptide aggregation poses substantial challenges in disease pathology and therapeutic development. While natural glycosylation may mitigate aggregation, its efficacy and underlying mechanisms remain poorly understood due to limited … Protein and peptide aggregation poses substantial challenges in disease pathology and therapeutic development. While natural glycosylation may mitigate aggregation, its efficacy and underlying mechanisms remain poorly understood due to limited access to homogeneous samples with complex glycans. This study addresses these knowledge gaps by investigating the natural glycosylation of islet amyloid polypeptide (IAPP), a peptide with therapeutic potential for type 2 diabetes but problematic aggregation. An optimized chemical synthesis enabled preparation of diverse IAPP glycoforms with complex glycan structures, allowing systematic evaluation of their effects on aggregation, cytotoxicity, and solubility. Sialylated glycans at Thr 30 completely inhibited IAPP aggregation, eliminated cytotoxicity toward pancreatic β cells, and enhanced solubility by up to 280-fold. Replica exchange molecular dynamics simulations revealed that glycosylation impedes adoption of a four-stranded β-sheet conformation in IAPP dimers. These findings advance the understanding of the role of natural glycosylation in aggregation and highlight its potential as an evolutionarily inspired strategy to enhance the therapeutic utility of IAPP.

Metabolic control of glycosylation forms for establishing glycan-dependent protein interaction networks

2025-06-18

Xingyu Liu , Li Yi , Zongtao Lin +6 more | Proceedings of the National Academy of Sciences

Protein–protein interactions (PPIs) are crucial for comprehending the molecular mechanisms and signaling pathways underlying diverse biological processes and disease progression. However, investigating PPIs involving membrane proteins is challenging due to … Protein–protein interactions (PPIs) are crucial for comprehending the molecular mechanisms and signaling pathways underlying diverse biological processes and disease progression. However, investigating PPIs involving membrane proteins is challenging due to the complexity and heterogeneity of glycosylation. To tackle this challenge, we developed an approach termed glycan-dependent affinity purification coupled with mass spectrometry (GAP–MS), specifically designed to characterize changes in glycoprotein PPIs under varying glycosylation conditions. GAP–MS integrates metabolic control of glycan profiles in cultured cells using small molecules referred to as glycan modifiers with affinity purification followed by mass spectrometry analysis (AP–MS). Here, GAP–MS was applied to characterize and compare the interaction networks under five different glycosylation states for four bait glycoproteins: BSG, CD44, EGFR, and SLC3A2. This analysis identified a network comprising 156 interactions, of which 131 were determined to be glycan dependent. Notably, the GAP–MS analysis of BSG provided distinct information regarding glycosylation-influenced interactions compared to the commonly used glycosylation site mutagenesis approach combined with AP–MS, emphasizing the unique advantages of GAP–MS. Collectively, GAP–MS presents distinct insights over existing methods in elucidating how specific glycosylation forms impact glycoprotein interactions. Additionally, the glycan-dependent interaction networks generated for these four glycoproteins serve as a valuable resource for guiding future functional investigations and therapeutic developments targeting the glycoproteins discussed in this study.

Lubricin's Mucin Domain Has Strong Polyproline Type-II Helical Character

2025-06-18

Bibo Feng , Ava Marks , Francis Kim +5 more | bioRxiv (Cold Spring Harbor Laboratory)

ABSTRACT Lubricin is a glycoprotein that is crucial for maintaining joint health by preventing joint wear by reducing joint friction in the boundary mode. Lubricin was recently observed to hinder … ABSTRACT Lubricin is a glycoprotein that is crucial for maintaining joint health by preventing joint wear by reducing joint friction in the boundary mode. Lubricin was recently observed to hinder the formation of uric acid crystals in the joint and prevent a form of gouty arthritis. However, despite lubricin’s great physiological importance, our current understanding of the molecular origins of lubricin’s beneficial properties is limited by a lack of detailed structural information regarding its central mucin domain: lubricin’s large size (227.5 kDa) and numerous glycosylations pose a substantial obstacle to conventional experimental methods for solving protein structures. In this work, we employ a combination of physics-based replica exchange molecular dynamics (REMD) simulations and circular dichroism (CD) experiments to shed light on the structure of lubricin’s central mucin domain. Using REMD, we model [KEPAPTTP] 2 , an amino acid repeat found throughout the mucin domain, and find that the mucin domain is likely to exhibit polyproline type II (PPII) helices, which are further stabilized by O-linked oligosaccharide chains. Motivated by these simulation results, we performed circular dichroism spectroscopy on fragments of the mucin domain that also show clear polyproline-II helical character, corroborating our computational findings. Altogether, this work provides strong evidence of a lubricin mucin domain with significant polyproline type II content. As polyproline helices are often also found in other glycoproteins with antifreeze properties, this work may also explain the atomistic underpinnings of their interfacial functions, including lubrication and competition with crystal formation. SIGNIFICANCE Lubricin is a mucinous glycoprotein containing a central heavily glycosylated domain that plays a crucial role in the lubrication of joints. However, little is known about the structure of this large central mucin domain, which makes the development of related therapeutics or biomedical devices challenging. In this work, we provide strong evidence that lubricin’s mucin domain possesses polyproline type II (PPII) character that is enhanced by glycosylation upon the basis of a combination of molecular dynamics simulations and circular dichroism experiments. Lubricin’s PPII character provides a molecular basis for its lubricating properties, which may provide insights into related antifreeze glycoproteins (AFGP) and the development of new biocompatible lubricants and ryo-preservatives.

SC134-deruxtecan a fucosyl-GM1 targeting ADC for small cell lung cancer therapy

2025-06-18

Bryony Heath , Bubacarr G. Kaira , Dhruma Thakker +7 more | Research Square (Research Square)

<title>Abstract</title> Background Small cell lung cancer (SCLC) remains a difficult disease to treat with poor long-term survival rates. New therapies offer modest overall survival benefit beyond that of chemotherapy alone, … <title>Abstract</title> Background Small cell lung cancer (SCLC) remains a difficult disease to treat with poor long-term survival rates. New therapies offer modest overall survival benefit beyond that of chemotherapy alone, necessitating the development of improved therapies. Fucosyl-GM1 (FucGM1) is a glycolipid highly expressed on SCLC cells, but virtually absent in normal tissues, suggesting strong potential for targeted therapy. We have developed SC134-deruxtecan, an antibody drug conjugate (ADC) targeting FucGM1 in SCLC, and characterized its preclinical activity. Methods SC134 binding specificity and affinity were tested through enzyme-linked immunosorbent assay (ELISA), surface plasmon resonance (SPR), flow cytometry against several SCLC cell lines, and immunohistochemistry (IHC) of clinical samples and animal tissues. In silico modelling supplemented the FucGM1 binding specificity. Internalization kinetics and colocalization of SC134 with the lysosomes were investigated through imaging flow cytometry. Direct cytotoxicity as well as bystander killing and antibody dependent cell cytotoxicity (ADCC) by SC134-deruxtecan were determined using in vitro cell cytotoxicity assays. SC134-deruxtecan’s efficacy was evaluated in vivo using a DMS79 xenograft model. Results SC134 specifically targets FucGM1, without GM1 cross-reactivity, with nanomolar affinity. In silico modelling of the SC134 FucGM1 binding site revealed a relatively narrow binding pocket, occupied by the terminal three glycans with multiple Fucose-engaging interactions. Robust FucGM1 expression in frozen SCLC patient tissues was evident, whilst tissue cross-reactivity analysis indicated non-human primates as well as mice as suitable toxicology models. FucGM1 binding by SC134 led to effective internalization, with a 6.9-hour half-life, lysosomal colocalization, culminating in sub-nanomolar efficiency drug delivery, across a range of payloads. Covalent deruxtecan conjugation of SC134 with a DAR8 and a cleavable linker showed effective (nanomolar) in vitro killing of SCLC cell lines such as DMS79 and DMS153, with concentration-dependent bystander killing of FucGM1-negative AGS cells. SCLC cell killing was further augmented through ADCC. Potent in vivo DMS79 xenograft killing was seen at 3mg/kg SC134-deruxtecan, which was well tolerated. Conclusions The tumour-specific nature of FucGM1, combined with the potent SCLC killing by SC134-deruxtecan underscore the development potential of SC134-deruxtecan for use as an ADC therapy against SCLC.

Development of Sucrose-Utilizing Escherichia coli Nissle 1917 for Efficient Heparosan Biosynthesis

2025-06-18

Yaozong Chen , Zhengwei Wan , Zhengjun Li | Metabolites

Background/Objectives: Heparosan is a component of the capsular polysaccharide in Escherichia coli K5 and Pasteurella multocida Type D. It shares a similar glycan structure with heparin and can be enzymatically … Background/Objectives: Heparosan is a component of the capsular polysaccharide in Escherichia coli K5 and Pasteurella multocida Type D. It shares a similar glycan structure with heparin and can be enzymatically modified to produce bioactive heparin. Methods: In this study, the probiotic strain E. coli Nissle 1917 (EcN), which naturally produces heparosan, was genetically engineered to utilize sucrose as a carbon source for growth while achieving high-yield heparosan biosynthesis. Results: By expressing the sucrose hydrolase genes sacA (from Bacillus subtilis) or spI (from Bifidobacterium adolescentis), EcN was enabled to utilize sucrose, achieving heparosan titers of 131 mg/L and 179 mg/L, respectively. Further metabolic engineering was performed to block the glycolytic and pentose phosphate pathways, thereby redirecting sucrose-derived glucose-6-phosphate and fructose-6-phosphate toward heparosan biosynthesis, while glycerol was supplemented as an auxiliary carbon source to support cell growth. Finally, the key biosynthesis genes galU, kfiD, and glmM were overexpressed, resulting in an engineered strain with a heparosan titer of 622 mg/L. Conclusions: This study represents the first successful engineering of EcN to utilize sucrose as the carbon source for growth, while achieving enhanced heparosan production through synergistic carbon source utilization. These findings establish a foundational strategy for employing this strain in the sucrose-based biosynthesis of other glycosaminoglycans.

E2F2/MUC1 Enhances Cell Stemness of Hepatocellular Carcinoma by Regulating the Notch Signaling Pathway

2025-06-18

Yao Huang , Jianxing Zeng , Teng Liu +3 more | Digestive Diseases and Sciences

Recent Progress of Small-molecule Inhibitors of O-GlcNAcase for Alzheimer’s Disease

2025-06-18

Sheng Sun , Jiafu Cao , Shujie Ji +1 more | Mini-Reviews in Medicinal Chemistry

Abstract: O-GlcNAcylation is a non-canonical form of protein glycosylation that occurs in nuclear, cytoplasmic, and mitochondrial proteins among all multicellular eukaryotes. There are only two enzymes that regulate this post-translational … Abstract: O-GlcNAcylation is a non-canonical form of protein glycosylation that occurs in nuclear, cytoplasmic, and mitochondrial proteins among all multicellular eukaryotes. There are only two enzymes that regulate this post-translational modification, one of which is O-GlcNAcase, a glycoside hydrolase that catalyzes the hydrolytic cleavage of O-GlcNAc from protein substrates. Related studies have shown that the reduction of O-GlcNAc levels is closely related to Alzheimer's disease, which is maintained by reducing the aggregation of tau via inhibiting O-GlcNAcase. Various smallmolecule O-GlcNAcase inhibitors with different chemical structures have been developed and used as chemical probes to explore the O-GlcNAc pathway. Although many reported inhibitors have shown that O-GlcNAcase activity has single-digit nmol IC50 values in binding assays, and molecules, such as LY-3372689, have entered phase II clinical studies, further exploration of novel OGlcNAcase inhibitors with higher inhibitory activity and specificity is still worthy of attention. This article reviews the pathogenesis and therapeutic role of O-GlcNAcase in Alzheimer's disease, as well as the recent progress of O-GlcNAcase small molecule inhibitors, including sugar-derived or non-sugar scaffolds, and summarizes the clinical progress and potential prospects of O-GlcNAcase inhibitors.

Preclinical Evaluation of a Near-Infrared Labelled Antibody Targeting the Tumour Associated Xenoantigen N-Glycolyl-Neuraminic Acid GM3 Ganglioside

2025-06-17

Kris Barreto , Wendy Bernhard , Dariέn Toledo +4 more | Molecular Imaging and Biology

Abstract Purpose Targeted and broadly applicable molecular targets are important for image guided surgery. Xenoantigens represent a particularly interesting class of targets. This study evaluates the xenoantigen N-glycolyl-neuraminic acid GM3 … Abstract Purpose Targeted and broadly applicable molecular targets are important for image guided surgery. Xenoantigens represent a particularly interesting class of targets. This study evaluates the xenoantigen N-glycolyl-neuraminic acid GM3 ganglioside (Neu5Gc-GM3) as a potential fluorescence-guided surgical tool. Procedures The antibody 14F7hT is conjugated to the near-infrared dye (IRDye800CW) and characterized under GLP conditions. The quality and stability of the 14F7hT-IRDye800CW probe was assessed. In vivo imaging using 14F7hT-IRDye800CW in mice with Neu5Gc GM3 positive and negative xenografts were compared to a control IgG-IRDye800CW probe targeting an epitope not present on the xenografts. Biodistribution, pharmacokinetics, and toxicity were evaluated. Results The 14F7hT-IRDye800CW probe was 98 ± 2% pure as determined by micro-capillary electrophoresis. The KDapp as determined by binding cell-lines expressing the target was unchanged after conjugation. We demonstrate a peak accumulation window of 12 – 48 h in murine xenografts with male and female CD-1 nude mice administered 0.5 nmoles of the probe (i.v.) and very low uptake in other tissues. Preclinical toxicity studies in male and female balb/c mice support a no observed adverse effect level (NOAEL) of 50 mg/kg in mice. Conclusions The 14F7hT-IRDye800CW probe was found to be safe and have low non-specific uptake in a model organism known to express the target. These data support future clinical development of the probe.

SARS-CoV-2 Evolved Variants Bind to Sialylated Gangliosides and Are Inhibited by a Tetravalent Sialo-Glycocluster

2025-06-17

Geetanjali Negi , V. K. PANDEY , Poojitha Sai Potharaju +4 more | ACS Infectious Diseases

The altered tropism and infection severity of the evolved SARS-CoV-2 variants indicate engagement of attachment factors other than the ACE2 receptor for the cellular attachment and entry of the virus. … The altered tropism and infection severity of the evolved SARS-CoV-2 variants indicate engagement of attachment factors other than the ACE2 receptor for the cellular attachment and entry of the virus. In this work, we report the binding of Omicron, Delta, and B.1.1.8 (A2a type) variants to gangliosides (GD1a, GM3, GM1) with terminal sialic acid (SA). The binding kinetics of intact virus particles to these ganglioside-embedded lipid membranes reveal that the affinity of Omicron for GD1a (two SA residues) is the highest, and the lowest affinity is that of B.1.1.8 for GM1 (one SA at the branched chain). Our TIRF imaging data confirm that SA and acetylated SA can inhibit the virus attachment to the bilayers but at millimolar concentration. We evaluated tetravalent glycoclusters, i.e., sialo-porphyrin, galactose-porphyrin, and glucose-porphyrin, as multivalent inhibitors of SARS-CoV-2. Our results show that membrane attachment of the variants is blocked by the micromolar concentration of sialo-porphyrin. Even the glycocluster effectively inhibits cellular infection caused by the variants.

Targeted O-GlcNAcylation of CK2α Triggers Its Ubiquitin-Proteasome Degradation and Alters Downstream Phosphorylation

2025-06-16

Tongyang Xu , Bowen Ma , Yuanpei Li +3 more | ACS Chemical Biology

O-Linked β-N-acetylglucosamine-modification (O-GlcNAcylation) is an important post-translational modification (PTM), yet dissecting its protein-specific functions has remained challenging. Here, we applied our previously reported chemical biology tool, the O-GlcNAcylation Targeting Chimera … O-Linked β-N-acetylglucosamine-modification (O-GlcNAcylation) is an important post-translational modification (PTM), yet dissecting its protein-specific functions has remained challenging. Here, we applied our previously reported chemical biology tool, the O-GlcNAcylation Targeting Chimera (OGTAC), to specifically induce O-GlcNAcylation of the casein kinase II subunit α (CK2α) at Ser347 in living cells. We found that this targeted O-GlcNAcylation destabilized CK2α through ubiquitin-proteasome degradation and enhanced its interaction with cereblon (CRBN). Overexpression and knockdown experiments also indicated CK2α as a substrate of the Cullin-RING E3 ubiquitin ligase 4-CRBN (CRL4CRBN) E3 ligase complex. Furthermore, the OGTAC-induced O-GlcNAcylation of CK2α reprogrammed phosphorylation of Akt and PFKP. These findings reveal that a single O-GlcNAc modification can serve as a molecular switch, controlling the protein stability and downstream phosphorylation of CK2α. More broadly, our results highlight the profound utility of the OGTAC-mediated O-GlcNAcylation to interrogate its cellular functions with specificity, overcoming limitations inherent to prior global perturbation methods.

Learning with Privileged Knowledge Distillation for Improved Peptide–Protein Docking

2025-06-16

Zicong Zhang , Jacob Verburgt , Yuki Kagaya +2 more | ACS Omega

Dissecting the biological impact of GBA1 mutations using multi-omics in an isogenic setting

2025-06-15

Pilar Álvarez Jerez , Peter Wild Crea , Dhairya Patel +7 more | bioRxiv (Cold Spring Harbor Laboratory)

GBA1 is a risk gene for multiple neurodegenerative diseases, including Lewy Body Dementia and Parkinsons disease, and biallelic pathogenic variants in the gene result in the lysosomal storage disorder Gaucher … GBA1 is a risk gene for multiple neurodegenerative diseases, including Lewy Body Dementia and Parkinsons disease, and biallelic pathogenic variants in the gene result in the lysosomal storage disorder Gaucher disease. GBA1 encodes the enzyme glucocerebrosidase (GCase), and alterations in the gene result in reduced enzymatic activity, which affects lysosome function downstream. Induced pluripotent stem cells (iPSCs) are a useful tool for testing the functional consequences of gene variants in an isogenic setting. Additionally, they can be used to perform multiomic studies to explore biological effects independent of disease mechanisms. Using CRISPR-edited isogenic KOLF2.1J iPSC lines containing pathogenic GBA1 variants D409H (p.D448H), D409V (p.D448V) and GBA1 knockout line generated by the iPSC Neurodegenerative Disease Initiative (iNDI), we examined potential molecular mechanisms and downstream consequences of GCase reduction. In this study, we confirm that this isogenic series behaves as expected for loss of function variants, despite the known difficulties with GBA1 editing. We identified that there are limited overlapping results across cell types suggesting potential different downstream effects caused by GBA1 variants. Additionally, we note that RNA-based quantitation may not be the best method to characterize GCase mechanisms, but protein and metabolomic analyses may be used to evaluate differences across genotypes.

Aberrations in the glycosylation of receptor tyrosine kinases: A focus on lung adenocarcinoma

2025-06-14

Anna M. Dmitrieva , Ivo Kocák , Lydia Meder | CytoJournal

Lung cancer is the leading cause of cancer-related deaths worldwide, with genetic- and protein-based diagnostics playing a crucial role in disease detection and improving patient outcomes. Glycosylation, a major post-translational … Lung cancer is the leading cause of cancer-related deaths worldwide, with genetic- and protein-based diagnostics playing a crucial role in disease detection and improving patient outcomes. Glycosylation, a major post-translational modification, has recently emerged as a factor influencing cancer progression, immune evasion, and therapeutic resistance. Aberrant glycosylation patterns, particularly among receptor tyrosine kinases (RTKs), have been shown to modulate oncogenic signaling pathways and influence tumor growth. This review provides a comprehensive overview of how glycosylation alterations affect the stability, function, and therapeutic targeting of key RTKs relevant in lung adenocarcinoma: Epidermal growth factor receptor, human epidermal growth factor receptor 2, and cellular mesenchymal-epithelial transition factor, rearranged during transfection, anaplastic lymphoma kinase, and ROS proto-oncogene 1 receptor tyrosine kinase. Despite substantial advances in targeted therapies, initial and acquired resistance remain a major challenge in the treatment of lung cancer. There is growing evidence that strategies targeting glycosylation can be combined with established treatment protocols to help overcome resistance. Finally, we propose future directions for the advancement of glycosylation-based approaches to improve precision medicine.

Mechanisms of GIP in inhibiting cancer growth: Updates and perspectives

2025-06-14

Aixin Wang , Xinyu Ye , Gerald J. Mizejewski +1 more | International Journal of Pharmaceutics

A computational analysis of the glycoprotein LRP1 structure and the role of glycans as quaternary glue

2025-06-14

Gian Marco Tuveri , Marco Basile , Silvia Acosta‐Gutiérrez +6 more | bioRxiv (Cold Spring Harbor Laboratory)

Abstract The low-density lipoprotein receptor-related protein 1 (LRP1) plays a critical role in development and transport across the blood-brain barrier (BBB), yet until now, its molecular architecture remained unresolved due … Abstract The low-density lipoprotein receptor-related protein 1 (LRP1) plays a critical role in development and transport across the blood-brain barrier (BBB), yet until now, its molecular architecture remained unresolved due to the absence of an experimentally determined structure. Using homology modeling and neural network-based structure prediction algorithms, complemented with molecular dynamics (MD) simulations, we propose a comprehensive model of LRP1 structures. We observe a natural dimerization mechanism and provide insight into the dynamic behavior of its flexible domains under physiological conditions. We investigated the stability of non-covalent interactions keeping LRP1’s α and β chains linked together, and found the energy required to break the link is 180±2 kT. The MD characterization highlights the fundamental role of glycans in the creation of LRP1’s quaternary structure, increasing the number of intra-dimeric contacts. This study opens new avenues for targeted drug design strategies, enhancing our molecular understanding of LRP1’s receptor-mediated transport in the brain and the key mediation of glycosylation in protein-protein interactions.

Development of derivatization-enhanced EIEIO-driven glycosidic linkage sequencing (DEED-GL-Seq) strategy and its application to glycogen-sourced oligosaccharides profiling

2025-06-14

Xin Zheng , Yufang Ma , Xinge Cui +7 more | Carbohydrate Polymers

Differential Leukocyte Count Responses Post Injection of Duffy-binding-like Domain-2β of PfEMP1 Recombinant Protein in Wistar Rat

2025-06-13

Zahniar Zahniar , Erma Sulistyaningsih , Sheilla Rachmania +2 more | Medical Laboratory Technology Journal

Malaria due to Plasmodium falciparum causes a high mortality rate, and vaccination is a valuable approach to control it. One malaria vaccine candidate is Plasmodium falciparum erythrocyte membrane protein-1 (PfEMP1), … Malaria due to Plasmodium falciparum causes a high mortality rate, and vaccination is a valuable approach to control it. One malaria vaccine candidate is Plasmodium falciparum erythrocyte membrane protein-1 (PfEMP1), specifically Duffy binding-like 2β (DBL2β) domain (DBL2β-PfEMP1), which has a vital role in severe malaria pathogenesis. The DBL2β-PfEMP1 recombinant protein is immunogenic. This study aimed to investigate the immune response of DBL2β-PfEMP1 protein by analyzing the differential leukocyte count. Twenty-three rats were randomly divided into control and five treatment groups. Rats were injected on days 0, 21, and 42 with a physiological solution of 0.9% NaCl, adjuvant, DBL2β-PfEMP1 protein, and each mixture of DBL2β-PfEMP1 protein with doses of 150, 300, and 450 µg/200gBW and adjuvant. Blood was collected on day 56 and prepared for differential leukocyte count examination with a visual microscopic examination by two expert observers. The results showed that DBL2β-PfEMP1 recombinant protein and adjuvant increased the eosinophils and neutrophils but decreased monocytes and lymphocytes and did not affect the basophils. Statistical analysis showed significant differences between groups for eosinophils (between control and DBL groups; Adj and DBL groups; DBL and other groups except DBL150+adj) and monocytes (between control and all doşe groups with adjuvant; DBL and all doşe groups with aduvant), but not for basophils, neutrophils, and lymphocytes. In conclusion, the serial injection of DBL2β-PfEMP1 recombinant protein showed different responses in each leukocyte cell type. Further analysis by time-series differential leukocyte count examination will be essential to determine the responses of each type of leukocyte to support the research on malaria vaccine development.

Increased O-GlcNAcylation in Leukocytes from Overweight Pediatric Subjects: A Pilot Study

2025-06-13

Alessia Remigante , Sara Spinelli , Gianluca Rizzo +5 more | International Journal of Molecular Sciences

Type II diabetes mellitus (T2D) is a metabolic disorder. Childhood overweight or obesity raises the risk for developing T2D later in life. Early identification of at-risk individuals is fundamental for … Type II diabetes mellitus (T2D) is a metabolic disorder. Childhood overweight or obesity raises the risk for developing T2D later in life. Early identification of at-risk individuals is fundamental for disease prevention and patient management. The scope of this pilot study was to explore whether leukocyte protein O-GlcNAc modification is elevated in an overweight pediatric cohort. Eight overweight and eight normal-weight children aged 3–13 years were recruited at the Papardo General Hospital (Messina, Italy). Physical exams, complete blood tests, and determination of leukocyte protein O-GlcNAcylation were carried out. Protein O-GlcNAcylation was higher in leucocytes from overweight children compared to normal-weight children, and was significantly correlated with BMI, metabolic markers (LDL-cholesterol/triglycerides), and the inflammatory marker CRP. This study suggests that leukocyte protein O-GlcNAcylation may represent a novel biomarker for the early detection of metabolic abnormalities that may lead to the development of pre-diabetes or T2D later in life.

Dietary plant-derived lectins induce oxidative stress, metabolic dysfunction, apoptosis and neuroinflammation in mice brain

2025-06-13

Nikoloz Zhgenti , Otar Bibilashvili , George Burjanadze +4 more | Nutritional Neuroscience

Background: Lectins are carbohydrate-binding proteins found in plants and animals. While they serve essential biological functions, certain plant-derived lectins-especially from legumes-may exert neurotoxic effects through the gut-brain axis. The growing … Background: Lectins are carbohydrate-binding proteins found in plants and animals. While they serve essential biological functions, certain plant-derived lectins-especially from legumes-may exert neurotoxic effects through the gut-brain axis. The growing intake of raw plant-based foods, including lectin-rich sprouts, raises safety concerns.Objective: To evaluate the neurotoxic potential of a galactose-specific lectin (BS-Gal) isolated from bean sprouts, with a focus on oxidative stress, energy metabolism, and neuroinflammation in mice.Methods: Mice were chronically administered BS-Gal orally. Brain regions (substantia nigra, cerebellum, brainstem) were analyzed for oxidative markers, metabolic enzymes, apoptotic signals, and inflammatory mediators using biochemical assays and immunoblotting.Results: BS-Gal significantly increased hydrogen peroxide, nitric oxide, and malondialdehyde levels, alongside reduced antioxidant enzyme activities, indicating oxidative damage. Glycolytic and citric acid cycle enzymes were suppressed, suggesting disrupted cellular metabolism. Apoptotic analysis revealed elevated pro-apoptotic markers (Bad, Bax) and reduced anti-apoptotic proteins (Bcl-2, Bcl-xL). Neuroinflammation was evident via NF-κB activation, increased proinflammatory cytokines (TNF-α, IL-6, IL-1β), and decreased anti-inflammatory markers (IκB-α, IL-4, IL-10, TGF-β).Conclusion: Chronic oral exposure to BS-Gal induces oxidative stress, metabolic dysfunction, and neuroinflammation in key mouse brain regions. These findings suggest potential neurotoxic risks associated with dietary intake of lectin-rich plant foods like bean sprouts.

Abstract P2-06-12: MGAT1-Mediated Glycosylation Orchestrates Immune Checkpoints and Antitumor Immunity

2025-06-13

Junlong Chi | Clinical Cancer Research

Abstract Despite the widespread application of immunotherapy, treating immune-cold tumors remains a significant challenge in cancer therapy. Using multiomic spatial analyses and experimental validation, we have identified MGAT1, a glycosyltransferase, … Abstract Despite the widespread application of immunotherapy, treating immune-cold tumors remains a significant challenge in cancer therapy. Using multiomic spatial analyses and experimental validation, we have identified MGAT1, a glycosyltransferase, as a pivotal factor governing tumor immune response. Overexpression of MGAT1 leads to immune evasion due to aberrant elevation of CD73 membrane translocation, which suppresses CD8+ T cell function, especially in immune-cold triple-negative breast cancer (TNBC). Mechanistically, addition of N-acetylglucosamine to CD73 by MGAT1 enables the CD73 dimerization necessary for CD73 loading onto VAMP3, ensuring membrane fusion. We further show that THBS1 is an upstream etiological factor orchestrating the MGAT1-CD73-VAMP3-adenosine axis in suppressing CD8+ T cell antitumor activity. Spatial transcriptomic profiling reveals spatially resolved features of interacting malignant and immune cells pertaining to expression levels of MGAT1 and CD73. In preclinical models of TNBC, W-GTF01, a newly developed inhibitor, specifically blocked the MGAT1-catalyzed CD73 glycosylation, sensitizing refractory tumors to anti-PD-L1 therapy via restoring capacity to elicit a CD8+ IFNγ-producing T cell response. Collectively, our findings uncover a strategy for targeting the immunosuppressive molecule CD73 by inhibiting MGAT1. Citation Format: Junlong Chi. MGAT1-Mediated Glycosylation Orchestrates Immune Checkpoints and Antitumor Immunity [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2024; 2024 Dec 10-13; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2025;31(12 Suppl):Abstract nr P2-06-12.

Abstract P5-01-23: Linking Spatial Distribution of Core Fucosylated N-Glycans to Triple Negative Breast Cancer Outcomes

2025-06-13

Jaclyn Dunne , Laura S. Spruill , Taylor S. Hulahan +5 more | Clinical Cancer Research

Abstract Triple Negative Breast Cancer (TNBC) is an aggressive breast cancer subtype with poor prognosis, partly due to its heterogenous molecular profile. Unlike other breast cancer subtypes, targeted therapies for … Abstract Triple Negative Breast Cancer (TNBC) is an aggressive breast cancer subtype with poor prognosis, partly due to its heterogenous molecular profile. Unlike other breast cancer subtypes, targeted therapies for TNBC are lacking, highlighting an urgent need for a better understanding of the underlying biology of the disease that can be used to develop more effective, tailored therapies. In this study, changes in glycosylation of TNBC primary tumors were analyzed in order to gain better insight into the biology of the disease with the goal of pinpointing specific glycan structures that might be useful as diagnostic and prognostic biomarkers that could assist in early detection, risk assessment and creating personalized treatments. Our past work studying glycosylation in breast cancer has linked specific glycan structural classes to different tissue regions, including stromal, necrotic and tumor areas. Fucosylation, a specific form of glycosylation, influences various immune and hormonal physiological processes and is frequently expressed by tumors. Previous studies by others have linked core fucosylation to increased proliferation, metastatic potential and therapeutic resistance in a variety of cancers, including breast cancer. Further, we have reported that tumor-associated core-fucosylated polylactosamine glycans are significantly more prevalent in metastatic breast cancers compared to non-metastatic ones. The present study utilizes MALDI Imaging Mass Spectrometry to elucidate the spatial distribution of core-fucosylated N-glycans in TNBC tissues and assess their correlation with clinical outcome, tumor stage and patient survival status. Tissue samples were from female TNBC patients that self-identified as African ancestry (n=79). Tissues were previously banked for all research purposes and not specifically for this study; MUSC IRB approval as exemption #4. Clinical data includes tumor stage and grade, tumor nuclear grade, receptor status, metastatic sites, histology, surgical plan, chemotherapy status, BMI, age, and family history of cancer. Data showed that core fucosylation associated with stage of TNBC, with increases in stage III (ANOVA ≤0.001). By random forest machine learning, a set of three core fucosylated glycans were the primary differentiating factors in discriminating between stages of TNBC. We further found 9 specific core-fucosylated N-glycans that associated with survival status in the cohort (5-year survival n=39 alive; n=41 deceased; Kaplan-Meier (Log-Rank Mantel Cox test) p-value ≤0.01, Hazard ratio ≥2.5. In summary, our analysis revealed that TNBC tumors with high levels of core fucosylation were frequently associated with advanced cancer stage and poor patient outcomes, including reduced overall survival. Further studies are warranted to explore the mechanistic role of these glycans in TNBC progression. The association between increased core fucosylation and adverse clinical outcomes underscores the potential utility for targeting core fucosylation, either alone or in combination with immune-stimulating therapies, to improve outcomes for TNBC patients. Citation Format: Jaclyn Dunne, Laura Spruill, Taylor Hulahan, Graham Colditz, Anand S. Mehta, Richard R. Drake, Marvella Ford, Peggi M. Angel. Linking Spatial Distribution of Core Fucosylated N-Glycans to Triple Negative Breast Cancer Outcomes [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2024; 2024 Dec 10-13; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2025;31(12 Suppl):Abstract nr P5-01-23.

Abstract P4-01-21: The clinical significance of disialoganglioside GD2 synthases in breast cancer

2025-06-13

Niamh O'Neill , Amber Li , Kefah Mokbel +4 more | Clinical Cancer Research

Abstract Introduction: Disialoganglioside GD2 is a glycosphingolipid found in the plasma membrane, consisting of a hydrophobic ceramide linked to a hydrophilic sialic acid-containing glycan chain. Its synthesis involves sequential glycosylation … Abstract Introduction: Disialoganglioside GD2 is a glycosphingolipid found in the plasma membrane, consisting of a hydrophobic ceramide linked to a hydrophilic sialic acid-containing glycan chain. Its synthesis involves sequential glycosylation and sialylation steps facilitated by multiple enzymes. Recent studies have identified GD2 as being overexpressed in certain cancers and cancer cells, potentially influencing their survival, motility, and invasive properties. This study aimed to investigate the clinical significance of GD2 synthases in breast cancer by examining their clinical, pathological, and prognostic associations. Materials and Methods: A cohort of human breast cancer and background tissues were assessed for expression of a group of disialoganglioside GD2 synthases using q-PCR and statistically analysed using Mann Whitney U tests for comparisons, ROC, logistic regression Kaplan-Meier and Baysian methods for survival analyses. The relationship between the expression of the enzymes and patient’s responses to drug therapies were also explored. Results: We tested eight key enzymes involved in GD2 synthesis and explored them as a coherent group of synthesis regulators. Excessive expression of B4GalT5 and, notably, ST8Sia1, two enzymes involved in GD2 synthesis, significantly influenced patients' clinical outcomes (p=0.023 and p=0.006, respectively). When treatment response was assessed from the public database (TCGA), patients with high levels of B4GalNT1 in breast cancer did not respond to chemotherapies (p&lt;0.00001) but showed response to endocrine and anti-Her2 therapies. This association was more pronounced in Luminal-B subtypes patients but had little connection with ER or Her2 alone. Conversely, patients with high levels of B3GalT4 were more sensitive to endocrine therapies (p=0.001) but showed no connection with chemotherapies. Further analysis using a combination of the three synthases provided a significantly effective prognostic indicator for patient survival, identifying two distinct divisions for the synthases as favourable and non-favourable for survival (p=0.0009, HR=2.02 (95%CI 1.33-3.08), a finding further supported by Bayesian analysis. The combination indicator, when stratified by ER, Her2 and TNBC subgrouping, revealed that the signature identified from the synthases is strongly associated with hormone status and the molecular subtype. Conclusions: These data indicate that GD2 synthases have potential as a significant indicators for prognosis and therapeutic responses in human breast cancer, particularly in association with hormone receptor status. Further work is warranted to unpick the potential mechanism/s underlying this phenomenon. Citation Format: Niamh O'Neill, Amber Li, Kefah Mokbel, Jia Tong, Lin Ye, Wen G. Jiang, Tracey A. Martin. The clinical significance of disialoganglioside GD2 synthases in breast cancer [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2024; 2024 Dec 10-13; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2025;31(12 Suppl):Abstract nr P4-01-21.

An ultrasensitive and modular platform to detect Siglec ligands and control immune cell function

2025-06-12

Zeinab Jame-Chenarboo , Edward N. Schmidt , Madeline Crichton +7 more | bioRxiv (Cold Spring Harbor Laboratory)

Abstract Siglecs are immunomodulatory receptors that regulate immune cell function. A fundamental challenge in studying Siglec-ligand interactions is the low affinity of Siglecs for their ligands. Inspired by how nature … Abstract Siglecs are immunomodulatory receptors that regulate immune cell function. A fundamental challenge in studying Siglec-ligand interactions is the low affinity of Siglecs for their ligands. Inspired by how nature uses multivalency, we developed Siglec-liposomes as a highly multivalent and versatile platform for detecting Siglec glycan ligands in which recombinant Siglecs were conjugated to liposomes using the SpyCatcher-SpyTag system. Siglec-liposomes offer tunable multivalency and a modular assembly, enabling presentation of different Siglecs on the same liposome. Using Siglec-liposomes, we profiled Siglec ligands on human leukocytes, revealing new insights into Siglec ligands. Moreover, Siglec-liposomes are in vivo compatible, where we demonstrated that Siglec-7-liposomes bind to the brain vasculature in a mucin-dependent manner. Given the abundance of Siglec ligands on T cells, we investigated whether Siglec-liposomes modulate T cell function and find that Siglec-7-liposomes increase T cell proliferation in a ST3Gal1-dependent and CD43-independent manner. Taken together, Siglec-liposomes are a versatile and sensitive tool for detecting Siglec ligands and immunomodulation.

Revisiting Proteus 2.0: Two Decades of Pioneering Lectin Crystallography at BioMol-Lab in Northeast Brazil

2025-06-12

Benildo Sousa Cavada , Kyria S. Nascimento , Vinícius Jose Silva Osterne | ACS Omega