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Vicente JB, Guerreiro ACL, Felgueiras B, Chapla D, Tehrani D, Moremen KW, Costa J. Glycosyltransferase 8 domain-containing protein 1 (GLT8D1) is a UDP-dependent galactosyltransferase. Sci Rep 2023; 13:21684. [PMID: 38066107 PMCID: PMC10709319 DOI: 10.1038/s41598-023-48605-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 11/28/2023] [Indexed: 12/18/2023] Open
Abstract
Glycosyltransferases (GTs) are enzymes that catalyze the formation of glycosidic bonds and hundreds of GTs have been identified so far in humans. Glycosyltransferase 8 domain-containing protein 1 (GLT8D1) has been associated with central nervous system diseases and cancer. However, evidence on its enzymatic properties, including its substrates, has been scarcely described. In this paper, we have produced and purified recombinant secretory GLT8D1. The enzyme was found to be N-glycosylated. Differential scanning fluorimetry was employed to analyze the stabilization of GLT8D1 by Mn2+ and nucleotides, revealing UDP as the most stabilizing nucleotide scaffold. GLT8D1 displayed glycosyltransferase activity from UDP-galactose onto N-acetylgalactosamine but with a low efficiency. Modeling of the structure revealed similarities with other GT-A fold enzymes in CAZy family GT8 and glycosyltransferases in other families with galactosyl-, glucosyl-, and xylosyltransferase activities, each with retaining catalytic mechanisms. Our study provides novel structural and functional insights into the properties of GLT8D1 with implications in pathological processes.
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Affiliation(s)
- João B Vicente
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157, Oeiras, Portugal
| | - Ana Catarina L Guerreiro
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157, Oeiras, Portugal
- iBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal
| | - Beatriz Felgueiras
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157, Oeiras, Portugal
| | - Digantkumar Chapla
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Daniel Tehrani
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Kelley W Moremen
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Júlia Costa
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157, Oeiras, Portugal.
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2
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Tvaroška I, Selvaraj C, Koča J. Selectins-The Two Dr. Jekyll and Mr. Hyde Faces of Adhesion Molecules-A Review. Molecules 2020; 25:molecules25122835. [PMID: 32575485 PMCID: PMC7355470 DOI: 10.3390/molecules25122835] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 05/27/2020] [Accepted: 06/17/2020] [Indexed: 02/06/2023] Open
Abstract
Selectins belong to a group of adhesion molecules that fulfill an essential role in immune and inflammatory responses and tissue healing. Selectins are glycoproteins that decode the information carried by glycan structures, and non-covalent interactions of selectins with these glycan structures mediate biological processes. The sialylated and fucosylated tetrasaccharide sLex is an essential glycan recognized by selectins. Several glycosyltransferases are responsible for the biosynthesis of the sLex tetrasaccharide. Selectins are involved in a sequence of interactions of circulated leukocytes with endothelial cells in the blood called the adhesion cascade. Recently, it has become evident that cancer cells utilize a similar adhesion cascade to promote metastases. However, like Dr. Jekyll and Mr. Hyde’s two faces, selectins also contribute to tissue destruction during some infections and inflammatory diseases. The most prominent function of selectins is associated with the initial stage of the leukocyte adhesion cascade, in which selectin binding enables tethering and rolling. The first adhesive event occurs through specific non-covalent interactions between selectins and their ligands, with glycans functioning as an interface between leukocytes or cancer cells and the endothelium. Targeting these interactions remains a principal strategy aimed at developing new therapies for the treatment of immune and inflammatory disorders and cancer. In this review, we will survey the significant contributions to and the current status of the understanding of the structure of selectins and the role of selectins in various biological processes. The potential of selectins and their ligands as therapeutic targets in chronic and acute inflammatory diseases and cancer will also be discussed. We will emphasize the structural characteristic of selectins and the catalytic mechanisms of glycosyltransferases involved in the biosynthesis of glycan recognition determinants. Furthermore, recent achievements in the synthesis of selectin inhibitors will be reviewed with a focus on the various strategies used for the development of glycosyltransferase inhibitors, including substrate analog inhibitors and transition state analog inhibitors, which are based on knowledge of the catalytic mechanism.
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Affiliation(s)
- Igor Tvaroška
- Central European Institute of Technology (CEITEC), Masaryk University, 62500 Brno, Czech Republic
- Institute of Chemistry, Slovak Academy of Sciences, 84538 Bratislava, Slovak Republic
- Correspondence: (I.T.); (J.K.); Tel.: +421-948-535-601 (I.T.); +420-731-682-606 (J.K.)
| | - Chandrabose Selvaraj
- Central European Institute of Technology (CEITEC), Masaryk University, 62500 Brno, Czech Republic
| | - Jaroslav Koča
- Central European Institute of Technology (CEITEC), Masaryk University, 62500 Brno, Czech Republic
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, 62500 Brno, Czech Republic
- Correspondence: (I.T.); (J.K.); Tel.: +421-948-535-601 (I.T.); +420-731-682-606 (J.K.)
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3
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Ming SA, Cottman-Thomas E, Black NC, Chen Y, Veeramachineni V, Peterson DC, Chen X, Tedaldi LM, Wagner GK, Cai C, Linhardt RJ, Vann WF. Interaction of Neisseria meningitidis Group X N-acetylglucosamine-1-phosphotransferase with its donor substrate. Glycobiology 2018; 28:100-107. [PMID: 29228283 DOI: 10.1093/glycob/cwx100] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 12/05/2017] [Indexed: 12/16/2022] Open
Abstract
Neisseria meningitidis Group X is an emerging cause of bacterial meningitis in Sub-Saharan Africa. The capsular polysaccharide of Group X is a homopolymer of N-acetylglucosamine α(1-4) phosphate and is a vaccine target for prevention of disease associated with this meningococcal serogroup. We have demonstrated previously that the formation of the polymer is catalyzed by a phosphotransferase which transfers N-acetylglucosamine-1-phosphate from UDP-N-acetylglucosamine to the 4-hydroxyl of the N-acetylglucosamine on the nonreducing end of the growing chain. In this study, we use substrate analogs of UDP-GlcNAc to define the enzyme/donor substrate interactions critical for catalysis. Our kinetic analysis of the phosphotransferase reaction is consistent with a sequential mechanism of substrate addition and product release. The use of novel uracil modified analogs designed by Wagner et al. enabled us to assess whether the CsxA-catalyzed reaction is consistent with a donor dependent conformational change. As expected with this model for glycosyltransferases, UDP-GlcNAc analogs with bulky uracil modifications are not substrates but are inhibitors. An analog with a smaller iodo uracil substitution is a substrate and a less potent inhibitor. Moreover, our survey of analogs with modifications on the N-acetylglucosamine residue of the sugar nucleotide donor highlights the importance of substituents at C2 and C4 of the sugar residue. The hydroxyl group at C4 and the structure of the acyl group at C2 are very important for specificity and substrate interactions during the polymerization reaction. While most analogs modified at C2 were inhibitors, acetamido analogs were also substrates suggesting the importance of the carbonyl group.
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Affiliation(s)
- Shonoi A Ming
- Laboratory of Bacterial Polysaccharides, FDA, Silver Spring, MD 20993, USA
| | | | - Natalee C Black
- Laboratory of Bacterial Polysaccharides, FDA, Silver Spring, MD 20993, USA
| | - Yi Chen
- Department of Chemistry, University of California, Davis, CA 95616, USA
| | | | - Dwight C Peterson
- Laboratory of Bacterial Polysaccharides, FDA, Silver Spring, MD 20993, USA
| | - Xi Chen
- Department of Chemistry, University of California, Davis, CA 95616, USA
| | | | - Gerd K Wagner
- Department of Chemistry, King's College, London SE 11DB, UK
| | - Chao Cai
- Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Robert J Linhardt
- Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Willie F Vann
- Laboratory of Bacterial Polysaccharides, FDA, Silver Spring, MD 20993, USA
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4
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Grimm LL, Weissbach S, Flügge F, Begemann N, Palcic MM, Peters T. Protein NMR Studies of Substrate Binding to Human Blood Group A and B Glycosyltransferases. Chembiochem 2017; 18:1260-1269. [PMID: 28256109 DOI: 10.1002/cbic.201700025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Indexed: 12/31/2022]
Abstract
Donor and acceptor substrate binding to human blood group A and B glycosyltransferases (GTA, GTB) has been studied by a variety of protein NMR experiments. Prior crystallographic studies had shown these enzymes to adopt an open conformation in the absence of substrates. Binding either of the donor substrate UDP-Gal or of UDP induces a semiclosed conformation. In the presence of both donor and acceptor substrates, the enzymes shift towards a closed conformation with ordering of an internal loop and the C-terminal residues, which then completely cover the donor-binding pocket. Chemical-shift titrations of uniformly 2 H,15 N-labeled GTA or GTB with UDP affected about 20 % of all crosspeaks in 1 H,15 N TROSY-HSQC spectra, reflecting substantial plasticity of the enzymes. On the other hand, it is this conformational flexibility that impedes NH backbone assignments. Chemical-shift-perturbation experiments with δ1-[13 C]methyl-Ile-labeled samples revealed two Ile residues-Ile123 at the bottom of the UDP binding pocket, and Ile192 as part of the internal loop-that were significantly disturbed upon stepwise addition of UDP and H-disaccharide, also revealing long-range perturbations. Finally, methyl TROSY-based relaxation dispersion experiments do not reveal micro- to millisecond timescale motions. Although this study reveals substantial conformational plasticity of GTA and GTB, the matter of how binding of substrates shifts the enzymes into catalytically competent states remains enigmatic.
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Affiliation(s)
- Lena Lisbeth Grimm
- Institute of Chemistry, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany
| | - Sophie Weissbach
- Institute of Chemistry, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany
| | - Friedemann Flügge
- Institute of Chemistry, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany
| | - Nora Begemann
- Institute of Chemistry, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany
| | - Monica M Palcic
- Department of Biochemistry and Microbiology, University of Victoria, P. O. Box 3800, STN CSC, Victoria, BC, V8W 3P6, Canada
| | - Thomas Peters
- Institute of Chemistry, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany
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5
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Kanabar V, Tedaldi L, Jiang J, Nie X, Panina I, Descroix K, Man F, Pitchford SC, Page CP, Wagner GK. Base-modified UDP-sugars reduce cell surface levels of P-selectin glycoprotein 1 (PSGL-1) on IL-1β-stimulated human monocytes. Glycobiology 2016; 26:1059-1071. [PMID: 27233805 PMCID: PMC5072147 DOI: 10.1093/glycob/cww053] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Revised: 04/07/2016] [Accepted: 04/22/2016] [Indexed: 12/26/2022] Open
Abstract
P-selectin glycoprotein ligand-1 (PSGL-1, CD162) is a cell-surface glycoprotein that is expressed, either constitutively or inducibly, on all myeloid and lymphoid cell lineages. PSGL-1 is implicated in cell-cell interactions between platelets, leukocytes and endothelial cells, and a key mediator of inflammatory cell recruitment and transmigration into tissues. Here, we have investigated the effects of the β-1,4-galactosyltransferase inhibitor 5-(5-formylthien-2-yl) UDP-Gal (5-FT UDP-Gal, compound 1: ) and two close derivatives on the cell surface levels of PSGL-1 on human peripheral blood mononuclear cells (hPBMCs). PSGL-1 levels were studied both under basal conditions, and upon stimulation of hPBMCs with interleukin-1β (IL-1β). Between 1 and 24 hours after IL-1β stimulation, we observed initial PSGL-1 shedding, followed by an increase in PSGL-1 levels on the cell surface, with a maximal window between IL-1β-induced and basal levels after 72 h. All three inhibitors reduce PSGL-1 levels on IL-1β-stimulated cells in a concentration-dependent manner, but show no such effect in resting cells. Compound 1: also affects the cell surface levels of adhesion molecule CD11b in IL-1β-stimulated hPBMCs, but not of glycoproteins CD14 and CCR2. This activity profile may be linked to the inhibition of global Sialyl Lewis presentation on hPBMCs by compound 1: , which we have also observed. Although this mechanistic explanation remains hypothetical at present, our results show, for the first time, that small molecules can discriminate between IL-1β-induced and basal levels of cell surface PSGL-1. These findings open new avenues for intervention with PSGL-1 presentation on the cell surface of primed hPBMCs and may have implications for anti-inflammatory drug development.
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Affiliation(s)
- Varsha Kanabar
- Sackler Institute of Pulmonary Pharmacology
- Institute of Pharmaceutical Science, King's College London, Franklin Wilkins Building, London SE1 9NH, UK
| | - Lauren Tedaldi
- Institute of Pharmaceutical Science, King's College London, Franklin Wilkins Building, London SE1 9NH, UK
- Department of Chemistry, Faculty of Natural & Mathematical Sciences, King's College London, Britannia House, 7 Trinity Street, London, SE1 1DB, UK
| | - Jingqian Jiang
- Department of Chemistry, Faculty of Natural & Mathematical Sciences, King's College London, Britannia House, 7 Trinity Street, London, SE1 1DB, UK
| | - Xiaodan Nie
- Sackler Institute of Pulmonary Pharmacology
- Institute of Pharmaceutical Science, King's College London, Franklin Wilkins Building, London SE1 9NH, UK
| | - Irina Panina
- Institute of Pharmaceutical Science, King's College London, Franklin Wilkins Building, London SE1 9NH, UK
| | - Karine Descroix
- School of Pharmacy, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Francis Man
- Sackler Institute of Pulmonary Pharmacology
- Institute of Pharmaceutical Science, King's College London, Franklin Wilkins Building, London SE1 9NH, UK
| | - Simon C Pitchford
- Sackler Institute of Pulmonary Pharmacology
- Institute of Pharmaceutical Science, King's College London, Franklin Wilkins Building, London SE1 9NH, UK
| | - Clive P Page
- Sackler Institute of Pulmonary Pharmacology
- Institute of Pharmaceutical Science, King's College London, Franklin Wilkins Building, London SE1 9NH, UK
| | - Gerd K Wagner
- Department of Chemistry, Faculty of Natural & Mathematical Sciences, King's College London, Britannia House, 7 Trinity Street, London, SE1 1DB, UK
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6
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Merino P, Delso I, Tejero T, Ghirardello M, Juste-Navarro V. Nucleoside Diphosphate Sugar Analogues that Target Glycosyltransferases. ASIAN J ORG CHEM 2016. [DOI: 10.1002/ajoc.201600396] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Pedro Merino
- Department of Synthesis and Structure of Biomolecules; Institute of Chemical Synthesis and Homogeneous Catalysis (ISQCH); University of Zaragoza, CSIC; Zaragoza, Aragón 50009 Spain
| | - Ignacio Delso
- NMR Service, Center of Chemistry and Materials of Aragon (CEQMA); University of Zaragoza, CSIC; Zaragoza, Aragón 50009 Spain
| | - Tomás Tejero
- Department of Synthesis and Structure of Biomolecules; Institute of Chemical Synthesis and Homogeneous Catalysis (ISQCH); University of Zaragoza, CSIC; Zaragoza, Aragón 50009 Spain
| | - Mattia Ghirardello
- Department of Synthesis and Structure of Biomolecules; Institute of Chemical Synthesis and Homogeneous Catalysis (ISQCH); University of Zaragoza, CSIC; Zaragoza, Aragón 50009 Spain
| | - Verónica Juste-Navarro
- Department of Synthesis and Structure of Biomolecules; Institute of Chemical Synthesis and Homogeneous Catalysis (ISQCH); University of Zaragoza, CSIC; Zaragoza, Aragón 50009 Spain
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7
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Zhan YT, Su HY, An W. Glycosyltransferases and non-alcoholic fatty liver disease. World J Gastroenterol 2016; 22:2483-2493. [PMID: 26937136 PMCID: PMC4768194 DOI: 10.3748/wjg.v22.i8.2483] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 10/22/2015] [Accepted: 11/19/2015] [Indexed: 02/06/2023] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease and its incidence is increasing worldwide. However, the underlying mechanisms leading to the development of NAFLD are still not fully understood. Glycosyltransferases (GTs) are a diverse class of enzymes involved in catalyzing the transfer of one or multiple sugar residues to a wide range of acceptor molecules. GTs mediate a wide range of functions from structure and storage to signaling, and play a key role in many fundamental biological processes. Therefore, it is anticipated that GTs have a role in the pathogenesis of NAFLD. In this article, we present an overview of the basic information on NAFLD, particularly GTs and glycosylation modification of certain molecules and their association with NAFLD pathogenesis. In addition, the effects and mechanisms of some GTs in the development of NAFLD are summarized.
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8
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Jiang J, Kanabar V, Padilla B, Man F, Pitchford SC, Page CP, Wagner GK. Uncharged nucleoside inhibitors of β-1,4-galactosyltransferase with activity in cells. Chem Commun (Camb) 2016; 52:3955-8. [DOI: 10.1039/c5cc09289b] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
5-Substituted uridine derivatives are uncharged galactosyltransferase inhibitors that reduce PSGL-1 expression in human monocytes.
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Affiliation(s)
- Jingqian Jiang
- Department of Chemistry
- King's College London
- Faculty of Natural & Mathematical Sciences
- London
- UK
| | - Varsha Kanabar
- Sackler Institute of Pulmonary Pharmacology & Institute of Pharmaceutical Science
- King's College London
- Faculty of Life Sciences & Medicine
- London
- UK
| | - Beatriz Padilla
- Sackler Institute of Pulmonary Pharmacology & Institute of Pharmaceutical Science
- King's College London
- Faculty of Life Sciences & Medicine
- London
- UK
| | - Francis Man
- Sackler Institute of Pulmonary Pharmacology & Institute of Pharmaceutical Science
- King's College London
- Faculty of Life Sciences & Medicine
- London
- UK
| | - Simon C. Pitchford
- Sackler Institute of Pulmonary Pharmacology & Institute of Pharmaceutical Science
- King's College London
- Faculty of Life Sciences & Medicine
- London
- UK
| | - Clive P. Page
- Sackler Institute of Pulmonary Pharmacology & Institute of Pharmaceutical Science
- King's College London
- Faculty of Life Sciences & Medicine
- London
- UK
| | - Gerd K. Wagner
- Department of Chemistry
- King's College London
- Faculty of Natural & Mathematical Sciences
- London
- UK
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9
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Wagner GK, Pesnot T, Palcic MM, Jørgensen R. Novel UDP-GalNAc Derivative Structures Provide Insight into the Donor Specificity of Human Blood Group Glycosyltransferase. J Biol Chem 2015; 290:31162-72. [PMID: 26527682 PMCID: PMC4692239 DOI: 10.1074/jbc.m115.681262] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Indexed: 01/17/2023] Open
Abstract
Two closely related glycosyltransferases are responsible for the final step of the biosynthesis of ABO(H) human blood group A and B antigens. The two enzymes differ by only four amino acid residues, which determine whether the enzymes transfer GalNAc from UDP-GalNAc or Gal from UDP-Gal to the H-antigen acceptor. The enzymes belong to the class of GT-A folded enzymes, grouped as GT6 in the CAZy database, and are characterized by a single domain with a metal dependent retaining reaction mechanism. However, the exact role of the four amino acid residues in the specificity of the enzymes is still unresolved. In this study, we report the first structural information of a dual specificity cis-AB blood group glycosyltransferase in complex with a synthetic UDP-GalNAc derivative. Interestingly, the GalNAc moiety adopts an unusual yet catalytically productive conformation in the binding pocket, which is different from the "tucked under" conformation previously observed for the UDP-Gal donor. In addition, we show that this UDP-GalNAc derivative in complex with the H-antigen acceptor provokes the same unusual binding pocket closure as seen for the corresponding UDP-Gal derivative. Despite this, the two derivatives show vastly different kinetic properties. Our results provide a important structural insight into the donor substrate specificity and utilization in blood group biosynthesis, which can very likely be exploited for the development of new glycosyltransferase inhibitors and probes.
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Affiliation(s)
- Gerd K Wagner
- From the Department of Chemistry, King's College London, Faculty of Natural & Mathematical Sciences, Britannia House, 7 Trinity Street, London SE1 1DB, United Kingdom
| | - Thomas Pesnot
- the University of East Anglia, School of Pharmacy, Norwich NR47TJ, England, and
| | - Monica M Palcic
- the Carlsberg Laboratory, Gamle Carlsberg Vej 10, DK-1799, Copenhagen V, Denmark
| | - Rene Jørgensen
- the Carlsberg Laboratory, Gamle Carlsberg Vej 10, DK-1799, Copenhagen V, Denmark
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10
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Abstract
The human blood group A and B antigens are synthesized by two highly homologous enzymes, glycosyltransferase A (GTA) and glycosyltransferase B (GTB), respectively. These enzymes catalyze the transfer of either GalNAc or Gal from their corresponding UDP-donors to αFuc1-2βGal-R terminating acceptors. GTA and GTB differ at only four of 354 amino acids (R176G, G235S, L266M, G268A), which alter the donor specificity from UDP-GalNAc to UDP-Gal. Blood type O individuals synthesize truncated or non-functional enzymes. The cloning, crystallization and X-ray structure elucidations for GTA and GTB have revealed key residues responsible for donor discrimination and acceptor binding. Structural studies suggest that numerous conformational changes occur during the catalytic cycle. Over 300 ABO alleles are tabulated in the blood group antigen mutation database (BGMUT) that provides a framework for structure-function studies. Natural mutations are found in all regions of GTA and GTB from the active site, flexible loops, stem region and surfaces remote from the active site. Our characterizations of natural mutants near a flexible loop (V175M), on a remote surface site (P156L), in the metal binding motif (M212V) and near the acceptor binding site (L232P) demonstrate the resiliency of GTA and GTB to mutagenesis.
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11
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Tvaroška I. Atomistic insight into the catalytic mechanism of glycosyltransferases by combined quantum mechanics/molecular mechanics (QM/MM) methods. Carbohydr Res 2015; 403:38-47. [DOI: 10.1016/j.carres.2014.06.017] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 06/12/2014] [Accepted: 06/16/2014] [Indexed: 01/17/2023]
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12
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Enzymatic synthesis of nucleobase-modified UDP-sugars: scope and limitations. Carbohydr Res 2014; 404:17-25. [PMID: 25662737 PMCID: PMC4340641 DOI: 10.1016/j.carres.2014.12.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 12/11/2014] [Accepted: 12/12/2014] [Indexed: 12/11/2022]
Abstract
Glucose-1-phosphate uridylyltransferase in conjunction with UDP-glucose pyrophosphorylase was found to catalyse the conversion of a range of 5-substituted UTP derivatives into the corresponding UDP-galactose derivatives in poor yield. Notably the 5-iodo derivative was not converted to UDP-sugar. In contrast, UDP-glucose pyrophosphorylase in conjunction with inorganic pyrophosphatase was particularly effective at converting 5-substituted UTP derivatives, including the iodo compound, into a range of gluco-configured 5-substituted UDP-sugar derivatives in good yields. Attempts to effect 4"-epimerization of these 5-substituted UDP-glucose with UDP-glucose 4"-epimerase from yeast were unsuccessful, while use of the corresponding enzyme from Erwinia amylovora resulted in efficient epimerization of only 5-iodo-UDP-Glc, but not the corresponding 5-aryl derivatives, to give 5-iodo-UDP-Gal. Given the established potential for Pd-mediated cross-coupling of 5-iodo-UDP-sugars, this provides convenient access to the galacto-configured 5-substituted-UDP-sugars from gluco-configured substrates and 5-iodo-UTP.
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13
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Brockhausen I. Crossroads between Bacterial and Mammalian Glycosyltransferases. Front Immunol 2014; 5:492. [PMID: 25368613 PMCID: PMC4202792 DOI: 10.3389/fimmu.2014.00492] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Accepted: 09/23/2014] [Indexed: 11/26/2022] Open
Abstract
Bacterial glycosyltransferases (GT) often synthesize the same glycan linkages as mammalian GT; yet, they usually have very little sequence identity. Nevertheless, enzymatic properties, folding, substrate specificities, and catalytic mechanisms of these enzyme proteins may have significant similarity. Thus, bacterial GT can be utilized for the enzymatic synthesis of both bacterial and mammalian types of complex glycan structures. A comparison is made here between mammalian and bacterial enzymes that synthesize epitopes found in mammalian glycoproteins, and those found in the O antigens of Gram-negative bacteria. These epitopes include Thomsen–Friedenreich (TF or T) antigen, blood group O, A, and B, type 1 and 2 chains, Lewis antigens, sialylated and fucosylated structures, and polysialic acids. Many different approaches can be taken to investigate the substrate binding and catalytic mechanisms of GT, including crystal structure analyses, mutations, comparison of amino acid sequences, NMR, and mass spectrometry. Knowledge of the protein structures and functions helps to design GT for specific glycan synthesis and to develop inhibitors. The goals are to develop new strategies to reduce bacterial virulence and to synthesize vaccines and other biologically active glycan structures.
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Affiliation(s)
- Inka Brockhausen
- Department of Medicine, Queen's University , Kingston, ON , Canada ; Department of Biomedical and Molecular Sciences, Queen's University , Kingston, ON , Canada
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14
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Jørgensen R, Batot G, Mannerstedt K, Imberty A, Breton C, Hindsgaul O, Royant A, Palcic MM. Structures of a human blood group glycosyltransferase in complex with a photo-activatable UDP-Gal derivative reveal two different binding conformations. ACTA CRYSTALLOGRAPHICA SECTION F-STRUCTURAL BIOLOGY COMMUNICATIONS 2014; 70:1015-21. [PMID: 25084373 DOI: 10.1107/s2053230x1401259x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 05/30/2014] [Indexed: 11/10/2022]
Abstract
Glycosyltransferases (GTs) catalyse the sequential addition of monosaccharides to specific acceptor molecules and play major roles in key biological processes. GTs are classified into two main families depending on the inverted or retained stereochemistry of the glycosidic bond formed during the reaction. While the mechanism of inverting enzymes is well characterized, the precise nature of retaining GTs is still a matter of much debate. In an attempt to clarify this issue, studies were initiated to identify reaction-intermediate states by using a crystallographic approach based on caged substrates. In this paper, two distinct structures of AA(Gly)B, a dual-specificity blood group synthase, are described in complex with a UDP-galactose derivative in which the O6'' atom is protected by a 2-nitrobenzyl group. The distinct conformations of the caged substrate in both structures of the enzyme illustrate the highly dynamic nature of its active site. An attempt was also made to photolyse the caged compound at low temperature, which unfortunately is not possible without damaging the uracil group as well. These results pave the way for kinetic crystallography experiments aiming at trapping and characterizing reaction-intermediate states in the mechanism of enzymatic glycosyl transfer.
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Affiliation(s)
- René Jørgensen
- Department of Microbiology and Infection Control, Statens Serum Institut, 5 Artillerivej, DK-2300 Copenhagen S, Denmark
| | - Gaëlle Batot
- Structural Biology Group, European Synchrotron Radiation Facility, 6 rue Jules Horowitz, F-38043 Grenoble, France
| | - Karin Mannerstedt
- Carlsberg Laboratory, Gamle Carlsberg Vej 10, DK-1799 Copenhagen V, Denmark
| | - Anne Imberty
- CERMAV-CNRS-Université Grenoble Alpes, BP 53, F-38041 Grenoble CEDEX 9, France
| | - Christelle Breton
- CERMAV-CNRS-Université Grenoble Alpes, BP 53, F-38041 Grenoble CEDEX 9, France
| | - Ole Hindsgaul
- Carlsberg Laboratory, Gamle Carlsberg Vej 10, DK-1799 Copenhagen V, Denmark
| | - Antoine Royant
- Structural Biology Group, European Synchrotron Radiation Facility, 71 Avenue des Martyrs, CS 40220, F-38043 Grenoble CEDEX 9, France
| | - Monica M Palcic
- Carlsberg Laboratory, Gamle Carlsberg Vej 10, DK-1799 Copenhagen V, Denmark
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15
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Tedaldi L, Wagner GK. Beyond substrate analogues: new inhibitor chemotypes for glycosyltransferases. MEDCHEMCOMM 2014. [DOI: 10.1039/c4md00086b] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
New inhibitor chemotypes for glycosyltransferases, which are not structurally derived from either donor or acceptor substrate, are being reviewed.
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Affiliation(s)
- Lauren Tedaldi
- Institute of Pharmaceutical Science
- School of Biomedical Sciences
- King's College London
- London
- UK
| | - Gerd K. Wagner
- Institute of Pharmaceutical Science
- School of Biomedical Sciences
- King's College London
- London
- UK
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