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Structure of human endo-α-1,2-mannosidase (MANEA), an antiviral host-glycosylation target. Proc Natl Acad Sci U S A 2020; 117:29595-29601. [PMID: 33154157 PMCID: PMC7703563 DOI: 10.1073/pnas.2013620117] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Mammalian protein N-linked glycosylation is critical for glycoprotein folding, quality control, trafficking, recognition, and function. N-linked glycans are synthesized from Glc3Man9GlcNAc2 precursors that are trimmed and modified in the endoplasmic reticulum (ER) and Golgi apparatus by glycoside hydrolases and glycosyltransferases. Endo-α-1,2-mannosidase (MANEA) is the sole endo-acting glycoside hydrolase involved in N-glycan trimming and is located within the Golgi, where it allows ER-escaped glycoproteins to bypass the classical N-glycosylation trimming pathway involving ER glucosidases I and II. There is considerable interest in the use of small molecules that disrupt N-linked glycosylation as therapeutic agents for diseases such as cancer and viral infection. Here we report the structure of the catalytic domain of human MANEA and complexes with substrate-derived inhibitors, which provide insight into dynamic loop movements that occur on substrate binding. We reveal structural features of the human enzyme that explain its substrate preference and the mechanistic basis for catalysis. These structures have inspired the development of new inhibitors that disrupt host protein N-glycan processing of viral glycans and reduce the infectivity of bovine viral diarrhea and dengue viruses in cellular models. These results may contribute to efforts aimed at developing broad-spectrum antiviral agents and help provide a more in-depth understanding of the biology of mammalian glycosylation.
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Fernandes PZ, Petricevic M, Sobala L, Davies GJ, Williams SJ. Exploration of Strategies for Mechanism-Based Inhibitor Design for Family GH99 endo-α-1,2-Mannanases. Chemistry 2018; 24:7464-7473. [PMID: 29508463 PMCID: PMC6001782 DOI: 10.1002/chem.201800435] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2018] [Indexed: 11/06/2022]
Abstract
endo-α-1,2-Mannosidases and -mannanases, members of glycoside hydrolase family 99 (GH99), cleave α-Glc/Man-1,3-α-Man-OR structures within mammalian N-linked glycans and fungal α-mannan, respectively. They are proposed to act through a two-step mechanism involving a 1,2-anhydrosugar "epoxide" intermediate incorporating two conserved catalytic carboxylates. In the first step, one carboxylate acts as a general base to deprotonate the 2-hydroxy group adjacent to the fissile glycosidic bond, and the other provides general acid assistance to the departure of the aglycon. We report herein the synthesis of two inhibitors designed to interact with either the general base (α-mannosyl-1,3-(2-aminodeoxymannojirimycin), Man2NH2 DMJ) or the general acid (α-mannosyl-1,3-mannoimidazole, ManManIm). Modest affinities were observed for an endo-α-1,2-mannanase from Bacteroides thetaiotaomicron. Structural studies revealed that Man2NH2 DMJ binds like other iminosugar inhibitors, which suggests that the poor inhibition shown by this compound is not a result of a failure to achieve the expected interaction with the general base, but rather the reduction in basicity of the endocyclic nitrogen caused by introduction of a vicinal, protonated amine at C2. ManManIm binds with the imidazole headgroup distorted downwards, a result of an unfavourable interaction with a conserved active site tyrosine. This study has identified important limitations associated with mechanism-inspired inhibitor design for GH99 enzymes.
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Affiliation(s)
- Pearl Z. Fernandes
- School of ChemistryBio21 Molecular Science and Biotechnology InstituteUniversity of MelbourneParkvilleVic3010Australia
| | - Marija Petricevic
- School of ChemistryBio21 Molecular Science and Biotechnology InstituteUniversity of MelbourneParkvilleVic3010Australia
| | - Lukasz Sobala
- York Structural Biology LaboratoryDepartment of ChemistryUniversity of YorkHeslingtonYO10 5DDUK
| | - Gideon J. Davies
- York Structural Biology LaboratoryDepartment of ChemistryUniversity of YorkHeslingtonYO10 5DDUK
| | - Spencer J. Williams
- School of ChemistryBio21 Molecular Science and Biotechnology InstituteUniversity of MelbourneParkvilleVic3010Australia
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Alonzi DS, Kukushkin NV, Allman SA, Hakki Z, Williams SJ, Pierce L, Dwek RA, Butters TD. Glycoprotein misfolding in the endoplasmic reticulum: identification of released oligosaccharides reveals a second ER-associated degradation pathway for Golgi-retrieved proteins. Cell Mol Life Sci 2013; 70:2799-814. [PMID: 23503623 PMCID: PMC11113499 DOI: 10.1007/s00018-013-1304-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Revised: 01/31/2013] [Accepted: 02/18/2013] [Indexed: 10/27/2022]
Abstract
Endoplasmic reticulum-associated degradation (ERAD) is a key cellular process whereby misfolded proteins are removed from the endoplasmic reticulum (ER) for subsequent degradation by the ubiquitin/proteasome system. In the present work, analysis of the released, free oligosaccharides (FOS) derived from all glycoproteins undergoing ERAD, has allowed a global estimation of the mechanisms of this pathway rather than following model proteins through degradative routes. Examining the FOS produced in endomannosidase-compromised cells following α-glucosidase inhibition has revealed a mechanism for clearing Golgi-retrieved glycoproteins that have failed to enter the ER quality control cycle. The Glc3Man7GlcNAc2 FOS species has been shown to be produced in the ER lumen by a mechanism involving a peptide: N-glycanase-like activity, and its production was sensitive to disruption of Golgi-ER trafficking. The detection of this oligosaccharide was unaffected by the overexpression of EDEM1 or cytosolic mannosidase, both of which increased the production of previously characterised cytosolically localised FOS. The lumenal FOS identified are therefore distinct in their production and regulation compared to FOS produced by the conventional route of misfolded glycoproteins directly removed from the ER. The production of such lumenal FOS is indicative of a novel degradative route for cellular glycoproteins that may exist under certain conditions.
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Affiliation(s)
- Dominic S. Alonzi
- Department of Biochemistry, Oxford Glycobiology Institute, University of Oxford, South Parks Road, Oxford, OX1 3QU UK
| | - Nikolay V. Kukushkin
- Department of Biochemistry, Oxford Glycobiology Institute, University of Oxford, South Parks Road, Oxford, OX1 3QU UK
| | - Sarah A. Allman
- Department of Biochemistry, Oxford Glycobiology Institute, University of Oxford, South Parks Road, Oxford, OX1 3QU UK
| | - Zalihe Hakki
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, VIC 3010 Australia
| | - Spencer J. Williams
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, VIC 3010 Australia
| | - Lorna Pierce
- Department of Biochemistry, Oxford Glycobiology Institute, University of Oxford, South Parks Road, Oxford, OX1 3QU UK
| | - Raymond A. Dwek
- Department of Biochemistry, Oxford Glycobiology Institute, University of Oxford, South Parks Road, Oxford, OX1 3QU UK
| | - Terry D. Butters
- Department of Biochemistry, Oxford Glycobiology Institute, University of Oxford, South Parks Road, Oxford, OX1 3QU UK
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Quach T, Tsegay S, Thompson AJ, Kukushkin NV, Alonzi DS, Butters TD, Davies GJ, Williams SJ. Fleetamine (3-O-α-d-glucopyranosyl-swainsonine): the synthesis of a hypothetical inhibitor of endo-α-mannosidase. ACTA ACUST UNITED AC 2012. [DOI: 10.1016/j.tetasy.2012.06.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Structural and mechanistic insight into N-glycan processing by endo-α-mannosidase. Proc Natl Acad Sci U S A 2012; 109:781-6. [PMID: 22219371 DOI: 10.1073/pnas.1111482109] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
N-linked glycans play key roles in protein folding, stability, and function. Biosynthetic modification of N-linked glycans, within the endoplasmic reticulum, features sequential trimming and readornment steps. One unusual enzyme, endo-α-mannosidase, cleaves mannoside linkages internally within an N-linked glycan chain, short circuiting the classical N-glycan biosynthetic pathway. Here, using two bacterial orthologs, we present the first structural and mechanistic dissection of endo-α-mannosidase. Structures solved at resolutions 1.7-2.1 Å reveal a (β/α)(8) barrel fold in which the catalytic center is present in a long substrate-binding groove, consistent with cleavage within the N-glycan chain. Enzymatic cleavage of authentic Glc(1/3)Man(9)GlcNAc(2) yields Glc(1/3)-Man. Using the bespoke substrate α-Glc-1,3-α-Man fluoride, the enzyme was shown to act with retention of anomeric configuration. Complexes with the established endo-α-mannosidase inhibitor α-Glc-1,3-deoxymannonojirimycin and a newly developed inhibitor, α-Glc-1,3-isofagomine, and with the reducing-end product α-1,2-mannobiose structurally define the -2 to +2 subsites of the enzyme. These structural and mechanistic data provide a foundation upon which to develop new enzyme inhibitors targeting the hijacking of N-glycan synthesis in viral disease and cancer.
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Cardona F, Parmeggiani C, Faggi E, Bonaccini C, Gratteri P, Sim L, Gloster T, Roberts S, Davies G, Rose D, Goti A. Total Syntheses of Casuarine and Its 6-O-α-Glucoside: Complementary Inhibition towards Glycoside Hydrolases of the GH31 and GH37 Families. Chemistry 2009; 15:1627-36. [DOI: 10.1002/chem.200801578] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Harvey DJ. Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update covering the period 1999-2000. MASS SPECTROMETRY REVIEWS 2006; 25:595-662. [PMID: 16642463 DOI: 10.1002/mas.20080] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
This review describes the use of matrix-assisted laser desorption/ionization (MALDI) mass spectrometry for the analysis of carbohydrates and glycoconjugates and continues coverage of the field from the previous review published in 1999 (D. J. Harvey, Matrix-assisted laser desorption/ionization mass spectrometry of carbohydrates, 1999, Mass Spectrom Rev, 18:349-451) for the period 1999-2000. As MALDI mass spectrometry is acquiring the status of a mature technique in this field, there has been a greater emphasis on applications rather than to method development as opposed to the previous review. The present review covers applications to plant-derived carbohydrates, N- and O-linked glycans from glycoproteins, glycated proteins, mucins, glycosaminoglycans, bacterial glycolipids, glycosphingolipids, glycoglycerolipids and related compounds, and glycosides. Applications of MALDI mass spectrometry to the study of enzymes acting on carbohydrates (glycosyltransferases and glycosidases) and to the synthesis of carbohydrates, are also covered.
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Affiliation(s)
- David J Harvey
- Department of Biochemistry, Oxford Glycobiology Institute, University of Oxford, Oxford OX1 3QU, United Kingdom.
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Spreitz J, Stütz AE. Golgi endomannosidase inhibitor, alpha-D-glucopyranosyl-(1 --> 3)-1-deoxymannojirimycin: a five-step synthesis from maltulose and examples of N-modified derivatives. Carbohydr Res 2005; 339:1823-7. [PMID: 15220094 DOI: 10.1016/j.carres.2004.04.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2004] [Accepted: 04/22/2004] [Indexed: 10/26/2022]
Abstract
Acid-catalysed O-acetylation of D-maltulose furnished the corresponding per-O-acetylated fructopyranose derivative that, after in situ deprotection at O-2 by reaction with triphenylphosphane dibromide, gave open-chain 2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl-(1 --> 4)-1,3,5-tri-O-acetyl-6-bromo-6-deoxy-D-fructose. Standard deprotection employing sodium methoxide in methanol at -30 degrees C, followed by treatment of the resulting free 6-bromodeoxymaltulose with sodium azide in N,N-dimethylformamide, allowed access to 6-azidodeoxymaltulose. Hydrogenation over Pearlman's catalyst, accompanied by intramolecular reductive amination, yielded the desired title compound. This route allows access to preparative quantities and to a range of novel analogues with improved biostability.
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Affiliation(s)
- Josef Spreitz
- Aglycon Company, Stremayrgasse 16, A-8010 Graz, Austria
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Spirodiketopiperazines of mannofuranose: carbopeptoid α-amino acid esters at the anomeric position of mannofuranose. ACTA ACUST UNITED AC 1998. [DOI: 10.1016/s0957-4166(98)00206-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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10
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Dax K, Ebner M, Peinsipp R, Stütz AE. Synthesis of a novel α-glucoside of the powerful glucosidase inhibitor 2,5-dideoxy-2,5-imino-d-mannitol via enzymatic glucosylation of 5-azido-5-deoxy-d-fructopyranose. Tetrahedron Lett 1997. [DOI: 10.1016/s0040-4039(96)02281-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Gradnig G, Legler G, Stütz AE. A novel approach to the 1-deoxynojirimycin system: synthesis from sucrose of 2-acetamido-1, 2-dideoxynojirimycin, as well as some 2-N-modified derivatives. Carbohydr Res 1996; 287:49-57. [PMID: 8765059 DOI: 10.1016/0008-6215(96)00065-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
6-Azido-1,3,4-tri-O-benzyl-6-deoxy-D-fructofuranose can be easily obtained in two steps from the known 6,6'-diazido-6,6'-dideoxysucrose (available in two steps from sucrose) and cyclized by controlled hydrogenation and concomitant intramolecular reductive amination to give 3,4,6-tri-O-benzyl-1,5-dideoxy-1,5-imino-D-mannitol, a partially protected derivative of 1-deoxymannojirimycin. After N-protection, position 2 is regio-specifically available to modification. This novel approach was taken advantage of in a synthesis of 2-acetamido-1,2- dideoxynojirimycin and new analogues thereof. Results of inhibition studies conducted with these new compounds employing N-acetylhexosaminidases of various sources are discussed.
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Affiliation(s)
- G Gradnig
- Institut für Organische Chemie der Technischen Universität Graz, Austria
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Nash RJ, Watson AA, Asano N. Chapter Five Polyhydroxylated alkaloids that inhibit glycosidases. ACTA ACUST UNITED AC 1996. [DOI: 10.1016/s0735-8210(96)80009-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
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Brandstetter TW, Wormald MR, Dwek RA, Butters TD, Platt FM, Tsitsanou KE, Zographos SE, Oikonomakos NG, Fleet GW. A galactopyranose analogue of hydantocidin. ACTA ACUST UNITED AC 1996. [DOI: 10.1016/0957-4166(95)00432-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Arnone A, Bravo P, Donadelli A, Resnati G. Fluorinated analogues of nojirimycin and mannojirimycin from a non-carbohydrate precursor. Tetrahedron 1996. [DOI: 10.1016/0040-4020(95)00859-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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15
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Estevez JC, Ardron H, Wormald MR, Brown D, Fleet GW. Spirocyclic peptides at the anomeric position of mannofuranose. Tetrahedron Lett 1994. [DOI: 10.1016/s0040-4039(00)78526-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Estevez JC, Estevez RJ, Ardron H, Wormald MR, Brown D, Fleet GW. Tri- and tetra-peptides incorporating an α-amino acid at the anomeric position of mannofuranose. Tetrahedron Lett 1994. [DOI: 10.1016/s0040-4039(00)78525-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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