1
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Baráth M, Jakubčinová J, Konyariková Z, Kozmon S, Mikušová K, Bella M. Synthesis, docking study and biological evaluation of ᴅ-fructofuranosyl and ᴅ-tagatofuranosyl sulfones as potential inhibitors of the mycobacterial galactan synthesis targeting the galactofuranosyltransferase GlfT2. Beilstein J Org Chem 2020; 16:1853-1862. [PMID: 32802202 PMCID: PMC7404141 DOI: 10.3762/bjoc.16.152] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 07/09/2020] [Indexed: 12/02/2022] Open
Abstract
A series of ten novel ᴅ-fructofuranosyl and ᴅ-tagatofuranosyl sulfones bearing a 1-O-phosphono moiety and three different substituents at C-2 has been prepared. Due to the structural similarities of these scaffolds to the native substrate of mycobacterial galactofuranosyltransferase GlfT2 in the transition state, we evaluated these compounds by computational methods, as well as in an enzyme assay for the possible inhibition of the mycobacterial galactan biosynthesis. Our data show that despite favorable docking scores to the active site of GlfT2, none of these compounds serve as efficient inhibitors of the enzymes involved in the mycobacterial galactan biosynthesis.
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Affiliation(s)
- Marek Baráth
- Institute of Chemistry Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 38 Bratislava, Slovakia
| | - Jana Jakubčinová
- Institute of Chemistry Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 38 Bratislava, Slovakia
| | - Zuzana Konyariková
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, SK-842 15 Bratislava, Slovakia
| | - Stanislav Kozmon
- Institute of Chemistry Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 38 Bratislava, Slovakia
| | - Katarína Mikušová
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, SK-842 15 Bratislava, Slovakia
| | - Maroš Bella
- Institute of Chemistry Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 38 Bratislava, Slovakia
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2
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Seničar M, Lafite P, Eliseeva SV, Petoud S, Landemarre L, Daniellou R. Galactofuranose-Related Enzymes: Challenges and Hopes. Int J Mol Sci 2020; 21:ijms21103465. [PMID: 32423053 PMCID: PMC7278926 DOI: 10.3390/ijms21103465] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 05/08/2020] [Accepted: 05/11/2020] [Indexed: 12/22/2022] Open
Abstract
Galactofuranose is a rare form of the well-known galactose sugar, and its occurrence in numerous pathogenic micro-organisms makes the enzymes responsible for its biosynthesis interesting targets. Herein, we review the role of these carbohydrate-related proteins with a special emphasis on the galactofuranosidases we recently characterized as an efficient recombinant biocatalyst.
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Affiliation(s)
- Mateja Seničar
- Institut de Chimie Organique et Analytique, CNRS UMR 7311, Université d’Orléans, Rue de Chartres, BP 6759, CEDEX 2, 45067 Orléans, France; (M.S.); (P.L.)
- Centre de Biophysique Moléculaire, CNRS UPR 4301, Rue Charles Sadron CS 8005, 45071 Orléans, France; (S.V.E.); (S.P.)
| | - Pierre Lafite
- Institut de Chimie Organique et Analytique, CNRS UMR 7311, Université d’Orléans, Rue de Chartres, BP 6759, CEDEX 2, 45067 Orléans, France; (M.S.); (P.L.)
| | - Svetlana V. Eliseeva
- Centre de Biophysique Moléculaire, CNRS UPR 4301, Rue Charles Sadron CS 8005, 45071 Orléans, France; (S.V.E.); (S.P.)
| | - Stéphane Petoud
- Centre de Biophysique Moléculaire, CNRS UPR 4301, Rue Charles Sadron CS 8005, 45071 Orléans, France; (S.V.E.); (S.P.)
| | | | - Richard Daniellou
- Institut de Chimie Organique et Analytique, CNRS UMR 7311, Université d’Orléans, Rue de Chartres, BP 6759, CEDEX 2, 45067 Orléans, France; (M.S.); (P.L.)
- Correspondence: ; Tel.: +33-238-494-978
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3
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Ahmadipour S, Pergolizzi G, Rejzek M, Field RA, Miller GJ. Chemoenzymatic Synthesis of C6-Modified Sugar Nucleotides To Probe the GDP-d-Mannose Dehydrogenase from Pseudomonas aeruginosa. Org Lett 2019; 21:4415-4419. [PMID: 31144821 DOI: 10.1021/acs.orglett.9b00967] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The chemoenzymatic synthesis of a series of C6-modified GDP-d-Man sugar nucleotides is described. This provides the first structure-function tools for the GDP-d-ManA producing GDP-d-mannose dehydrogenase (GMD) from Pseudomonas aeruginosa. Using a common C6 aldehyde functionalization strategy, chemical synthesis introduces deuterium enrichment, alongside one-carbon homologation at C6 for a series of mannose 1-phosphates. These materials are shown to be substrates for the GDP-mannose pyrophosphorylase from Salmonella enterica, delivering the required toolbox of modified GDP-d-Mans. C6-CH3 modified sugar-nucleotides are capable of reversibly preventing GDP-ManA production by GMD. The ketone product from oxidation of a C6-CH3 modified analogue is identified by high-resolution mass spectrometry.
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Affiliation(s)
- Sanaz Ahmadipour
- Lennard-Jones Laboratory, School of Chemical and Physical Sciences , Keele University , Keele , Staffordshire ST5 5BG , United Kingdom
| | - Giulia Pergolizzi
- Department of Biological Chemistry , John Innes Centre , Norwich Research Park , Norwich , NR4 7UH , United Kingdom
| | - Martin Rejzek
- Department of Biological Chemistry , John Innes Centre , Norwich Research Park , Norwich , NR4 7UH , United Kingdom
| | - Robert A Field
- Department of Biological Chemistry , John Innes Centre , Norwich Research Park , Norwich , NR4 7UH , United Kingdom
| | - Gavin J Miller
- Lennard-Jones Laboratory, School of Chemical and Physical Sciences , Keele University , Keele , Staffordshire ST5 5BG , United Kingdom
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4
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Ahmadipour S, Beswick L, Miller GJ. Recent advances in the enzymatic synthesis of sugar-nucleotides using nucleotidylyltransferases and glycosyltransferases. Carbohydr Res 2018; 469:38-47. [PMID: 30265902 DOI: 10.1016/j.carres.2018.09.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 09/09/2018] [Accepted: 09/10/2018] [Indexed: 11/18/2022]
Affiliation(s)
- Sanaz Ahmadipour
- Lennard-Jones Laboratory, School of Chemical and Physical Sciences, Keele University, Keele, Staffordshire, ST5 5BG, UK
| | - Laura Beswick
- Lennard-Jones Laboratory, School of Chemical and Physical Sciences, Keele University, Keele, Staffordshire, ST5 5BG, UK
| | - Gavin J Miller
- Lennard-Jones Laboratory, School of Chemical and Physical Sciences, Keele University, Keele, Staffordshire, ST5 5BG, UK.
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5
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1-C-phosphonomethyl- and 1-C-difluorophosphonomethyl-1,4-imino-l-arabinitols as Galf transferase inhibitors: A comparison. Carbohydr Res 2018; 461:45-50. [DOI: 10.1016/j.carres.2018.03.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 03/09/2018] [Accepted: 03/16/2018] [Indexed: 12/11/2022]
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6
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Janoš P, Kozmon S, Tvaroška I, Koča J. How Mycobacterium tuberculosis
Galactofuranosyl Transferase 2 (GlfT2) Generates Alternating β-(1-6) and β-(1-5) Linkages: A QM/MM Molecular Dynamics Study of the Chemical Steps. Chemistry 2018; 24:7051-7059. [DOI: 10.1002/chem.201800558] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Indexed: 11/12/2022]
Affiliation(s)
- Pavel Janoš
- Central European Institute of Technology (CEITEC); Masaryk University; Kamenice 5 625 00 Brno Czech Republic
- Faculty of Science-National Centre for Biomolecular Research; Masaryk University; Kamenice 5 625 00 Brno Czech Republic
| | - Stanislav Kozmon
- Central European Institute of Technology (CEITEC); Masaryk University; Kamenice 5 625 00 Brno Czech Republic
- Institute of Chemistry; Slovak Academy of Sciences; Dúbravská cesta 9 SK-845 38 Bratislava Slovakia
| | - Igor Tvaroška
- Central European Institute of Technology (CEITEC); Masaryk University; Kamenice 5 625 00 Brno Czech Republic
- Institute of Chemistry; Slovak Academy of Sciences; Dúbravská cesta 9 SK-845 38 Bratislava Slovakia
| | - Jaroslav Koča
- Central European Institute of Technology (CEITEC); Masaryk University; Kamenice 5 625 00 Brno Czech Republic
- Faculty of Science-National Centre for Biomolecular Research; Masaryk University; Kamenice 5 625 00 Brno Czech Republic
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7
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Cocaud C, Maujoin A, Zheng RB, Lowary TL, Rodrigues N, Percina N, Chartier A, Buron F, Routier S, Nicolas C, Martin OR. Triazole-Linked Iminosugars and Aromatic Systems as Simplified UDP-Galf
Mimics: Synthesis and Preliminary Evaluation as Galf
-Transferase Inhibitors. European J Org Chem 2017. [DOI: 10.1002/ejoc.201701283] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Chloé Cocaud
- Institut de Chimie Organique et Analytique; UMR CNRS 7311; Université d'Orléans; Rue de Chartres, BP 6759 45067 Orléans CEDEX 2 France
| | - Audrey Maujoin
- Institut de Chimie Organique et Analytique; UMR CNRS 7311; Université d'Orléans; Rue de Chartres, BP 6759 45067 Orléans CEDEX 2 France
| | - Ruixiang B. Zheng
- Alberta Glycomics Centre and Department of Chemistry; University of Alberta; GunningLemieux Chemistry Centre; 11227 Saskatchewan Drive T6G 2G2 Edmonton, Alberta Canada
| | - Todd L. Lowary
- Alberta Glycomics Centre and Department of Chemistry; University of Alberta; GunningLemieux Chemistry Centre; 11227 Saskatchewan Drive T6G 2G2 Edmonton, Alberta Canada
| | - Nuno Rodrigues
- Institut de Chimie Organique et Analytique; UMR CNRS 7311; Université d'Orléans; Rue de Chartres, BP 6759 45067 Orléans CEDEX 2 France
| | - Nathalie Percina
- Institut de Chimie Organique et Analytique; UMR CNRS 7311; Université d'Orléans; Rue de Chartres, BP 6759 45067 Orléans CEDEX 2 France
| | - Agnes Chartier
- Institut de Chimie Organique et Analytique; UMR CNRS 7311; Université d'Orléans; Rue de Chartres, BP 6759 45067 Orléans CEDEX 2 France
| | - Frédéric Buron
- Institut de Chimie Organique et Analytique; UMR CNRS 7311; Université d'Orléans; Rue de Chartres, BP 6759 45067 Orléans CEDEX 2 France
| | - Sylvain Routier
- Institut de Chimie Organique et Analytique; UMR CNRS 7311; Université d'Orléans; Rue de Chartres, BP 6759 45067 Orléans CEDEX 2 France
| | - Cyril Nicolas
- Institut de Chimie Organique et Analytique; UMR CNRS 7311; Université d'Orléans; Rue de Chartres, BP 6759 45067 Orléans CEDEX 2 France
| | - Olivier R. Martin
- Institut de Chimie Organique et Analytique; UMR CNRS 7311; Université d'Orléans; Rue de Chartres, BP 6759 45067 Orléans CEDEX 2 France
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8
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Harvey DJ. Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2011-2012. MASS SPECTROMETRY REVIEWS 2017; 36:255-422. [PMID: 26270629 DOI: 10.1002/mas.21471] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 01/15/2015] [Indexed: 06/04/2023]
Abstract
This review is the seventh update of the original article published in 1999 on the application of MALDI mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2012. General aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, and fragmentation are covered in the first part of the review and applications to various structural types constitute the remainder. The main groups of compound are oligo- and poly-saccharides, glycoproteins, glycolipids, glycosides, and biopharmaceuticals. Much of this material is presented in tabular form. Also discussed are medical and industrial applications of the technique, studies of enzyme reactions, and applications to chemical synthesis. © 2015 Wiley Periodicals, Inc. Mass Spec Rev 36:255-422, 2017.
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Affiliation(s)
- David J Harvey
- Department of Biochemistry, Oxford Glycobiology Institute, University of Oxford, Oxford, OX1 3QU, UK
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9
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Synthesis and biological properties of galactofuranosyl-containing fluorescent dyes. Bioorg Med Chem Lett 2017; 27:152-155. [PMID: 27956346 DOI: 10.1016/j.bmcl.2016.11.090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 11/29/2016] [Accepted: 11/30/2016] [Indexed: 11/23/2022]
Abstract
Two fluorescent galactofuranosides were synthesized and their biological activities evaluated on non-infected and Leishmania infected macrophages. Both tagged scaffolds were able to penetrate macrophages. Compared to the activity of the parent octyl galactofuranoside used as a reference, the fluorescein-conjugate showed altered biological properties while the rhodamine 6G one synergistically acted with the lipid chain to significantly increase antiparasitic activity.
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10
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Frédéric CJM, Tikad A, Fu J, Pan W, Zheng RB, Koizumi A, Xue X, Lowary TL, Vincent SP. Synthesis of Unprecedented Sulfonylated Phosphono-exo-Glycals Designed as Inhibitors of the Three Mycobacterial Galactofuranose Processing Enzymes. Chemistry 2016; 22:15913-15920. [PMID: 27628709 DOI: 10.1002/chem.201603161] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Indexed: 11/06/2022]
Abstract
This study reports a new methodology to synthesize exo-glycals bearing both a sulfone and a phosphonate. This synthetic strategy provides a way to generate exo-glycals displaying two electron-withdrawing groups and was applied to eight different carbohydrates from the furanose and pyranose series. The Z/E configurations of these tetrasubstituted enol ethers could be ascertained using NMR spectroscopic techniques. Deprotection of an exo-glycal followed by an UMP (uridine monophosphate) coupling generated two new UDP (uridine diphosphate)-galactofuranose analogues. These two Z/E isomers were evaluated as inhibitors of UGM, GlfT1, and GlfT2, the three mycobacterial galactofuranose processing enzymes. Molecule 46-(E) is the first characterized inhibitor of GlfT1 reported to date and was also found to efficiently inhibit UGM in a reversible manner. Interestingly, GlfT2 showed a better affinity for the (Z) isomer. The three enzymes studied in the present work are not only interesting because, mechanistically, they are still the topic of intense investigations, but also because they constitute very important targets for the development of novel antimycobacterial agents.
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Affiliation(s)
- Christophe J-M Frédéric
- University of Namur (UNamur), Département de Chimie, Laboratoire de Chimie Bio-Organique, rue de Bruxelles 61, 5000, Namur, Belgium
| | - Abdellatif Tikad
- University of Namur (UNamur), Département de Chimie, Laboratoire de Chimie Bio-Organique, rue de Bruxelles 61, 5000, Namur, Belgium
| | - Jian Fu
- University of Namur (UNamur), Département de Chimie, Laboratoire de Chimie Bio-Organique, rue de Bruxelles 61, 5000, Namur, Belgium
| | - Weidong Pan
- The Key Laboratory of Chemistry for Natural Products of Guizhou Province, Chinese Academy of Sciences, 202, Sha-chong South Road, Guiyang, 550002, P. R. China
| | - Ruixiang B Zheng
- Department of Chemistry and Alberta Glycomics Centre, University of Alberta, Gunning-Lemieux Chemistry Centre, 11227 Saskatchewan Drive, Edmonton, AB T6G 2G2, Canada
| | - Akihiko Koizumi
- Department of Chemistry and Alberta Glycomics Centre, University of Alberta, Gunning-Lemieux Chemistry Centre, 11227 Saskatchewan Drive, Edmonton, AB T6G 2G2, Canada
| | - Xiaochao Xue
- Department of Chemistry and Alberta Glycomics Centre, University of Alberta, Gunning-Lemieux Chemistry Centre, 11227 Saskatchewan Drive, Edmonton, AB T6G 2G2, Canada
| | - Todd L Lowary
- Department of Chemistry and Alberta Glycomics Centre, University of Alberta, Gunning-Lemieux Chemistry Centre, 11227 Saskatchewan Drive, Edmonton, AB T6G 2G2, Canada
| | - Stéphane P Vincent
- University of Namur (UNamur), Département de Chimie, Laboratoire de Chimie Bio-Organique, rue de Bruxelles 61, 5000, Namur, Belgium.
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11
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Poulin MB, Lowary TL. Chemical Insight into the Mechanism and Specificity of GlfT2, a Bifunctional Galactofuranosyltransferase from Mycobacteria. J Org Chem 2016; 81:8123-30. [PMID: 27557056 DOI: 10.1021/acs.joc.6b01501] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Mycobacteria, including the human pathogen Mycobacterium tuberculosis, produce a complex cell wall structure that is essential to survival. A key component of this structure is a glycoconjugate, the mycolyl-arabinogalactan-peptidoglycan complex, which has at its core a galactan domain composed of galactofuranose (Galf) residues linked to peptidoglycan. Because galactan biosynthesis is essential for mycobacterial viability, compounds that interfere with this process are potential therapeutic agents for treating mycobacterial diseases, including tuberculosis. Galactan biosynthesis in mycobacteria involves two glycosyltransferases, GlfT1 and GlfT2, which have been the subject of increasing interest in recent years. This Synopsis summarizes efforts to characterize the mechanism and specificity of GlfT2, which is responsible for introducing the majority of the Galf residues into mycobacterial galactan.
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Affiliation(s)
- Myles B Poulin
- Alberta Glycomics Centre and Department of Chemistry, University of Alberta , 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
| | - Todd L Lowary
- Alberta Glycomics Centre and Department of Chemistry, University of Alberta , 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
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12
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Synthesis and Evaluation of Bicyclo[3.1.0]hexane-Based UDP-Galf Analogues as Inhibitors of the Mycobacterial Galactofuranosyltransferase GlfT2. Molecules 2016; 21:molecules21081053. [PMID: 27529206 PMCID: PMC6272867 DOI: 10.3390/molecules21081053] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 08/05/2016] [Accepted: 08/06/2016] [Indexed: 11/17/2022] Open
Abstract
UDP-galactofuranose (UDP-Galf) is the donor substrate for both bifunctional galactofuranosyltransferases, GlfT1 and GlfT2, which are involved in the biosynthesis of mycobacterial galactan. In this paper, a group of UDP-Galf mimics were synthesized via reductive amination of a bicyclo[3.1.0]hexane-based amine by reacting with aromatic, linear, or uridine-containing aldehydes. These compounds were evaluated against GlfT2 using a coupled spectrophotometric assay, and were shown to be weak inhibitors of the enzyme.
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13
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Abstract
![]()
The cell surface (or cell wall) of bacteria is coated with carbohydrate
(or glycan) structures that play a number of important roles. These
include providing structural integrity, serving as a permeability
barrier to extracellular compounds (e.g., drugs) and modulating the
immune system of the host. Of interest to this Account is the cell
wall structure of mycobacteria. There are a host of different mycobacterial
species, some of which cause human disease. The most well-known is Mycobacterium tuberculosis, the causative agent of tuberculosis.
The mycobacterial cell wall is characterized by the presence of unusual
carbohydrate structures that fulfill the roles described above. However,
in many cases, a molecular-level understanding of how mycobacterial
cell wall glycans mediate these processes is lacking. Inspired
by a seminar he heard as a postdoctoral fellow, the author
began his independent research program with a focus on the chemical
synthesis of mycobacterial glycans. The goals were not only to develop
synthetic approaches to these unique structures but also to provide
molecules that could be used to probe their biological function. Initial
work addressed the preparation of fragments of two key polysaccharides,
arabinogalactan and lipoarabinomannan, which contain large numbers
of sugar residues in the furanose (five-membered) ring form. At the
time these investigations began, there were few methods reported for
the synthesis of oligosaccharides containing furanose rings. Thus,
early in the program, a major area of interest was methodology development,
particularly for the preparation of 1,2-cis-furanosides.
To solve this challenge, a range of conformationally restricted donors
have been developed, both in the author’s group and others,
which provide 1,2-cis-furanosidic linkages with high
stereoselectivity. These investigations were followed by application
of the developed
methods to the synthesis of a range of target molecules containing
arabinofuranose and galactofuranose residues. These molecules have
now found application in biochemical, immunological, and structural
biology investigations, which have shed light on their biosynthesis
and how these motifs are recognized by both the innate and adaptive
immune systems. More recently, attention has been directed toward
the synthesis
of another class of immunologically active mycobacterial cell wall
glycans, the extractable glycolipids. In this case, efforts have been
primarily on phenolic glycolipids, and the compounds synthesized have
been used to evaluate their ability to modulate cytokine release.
Over the past 20 years, the use of chemical synthesis to provide increasingly
complex glycan structures has provided significant benefit to the
burgeoning field of mycobacterial glycobiology. Through the efforts
of groups from around the globe, access to these compounds is now
possible via relatively straightforward methods. As the pool of mycobacterial
glycans continues to grow, so too will our understanding of their
role in disease, which will undoubtedly lead to new strategies to
prevent or treat mycobacterial infections.
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Affiliation(s)
- Todd L. Lowary
- Alberta Glycomics Centre
and Department of Chemistry, University of Alberta, Gunning−Lemieux
Chemistry Centre, Edmonton, Alberta T6G 2G2, Canada
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14
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Abstract
The cell surface (or cell wall) of bacteria is coated with carbohydrate (or glycan) structures that play a number of important roles. These include providing structural integrity, serving as a permeability barrier to extracellular compounds (e.g., drugs) and modulating the immune system of the host. Of interest to this Account is the cell wall structure of mycobacteria. There are a host of different mycobacterial species, some of which cause human disease. The most well-known is Mycobacterium tuberculosis, the causative agent of tuberculosis. The mycobacterial cell wall is characterized by the presence of unusual carbohydrate structures that fulfill the roles described above. However, in many cases, a molecular-level understanding of how mycobacterial cell wall glycans mediate these processes is lacking. Inspired by a seminar he heard as a postdoctoral fellow, the author began his independent research program with a focus on the chemical synthesis of mycobacterial glycans. The goals were not only to develop synthetic approaches to these unique structures but also to provide molecules that could be used to probe their biological function. Initial work addressed the preparation of fragments of two key polysaccharides, arabinogalactan and lipoarabinomannan, which contain large numbers of sugar residues in the furanose (five-membered) ring form. At the time these investigations began, there were few methods reported for the synthesis of oligosaccharides containing furanose rings. Thus, early in the program, a major area of interest was methodology development, particularly for the preparation of 1,2-cis-furanosides. To solve this challenge, a range of conformationally restricted donors have been developed, both in the author's group and others, which provide 1,2-cis-furanosidic linkages with high stereoselectivity. These investigations were followed by application of the developed methods to the synthesis of a range of target molecules containing arabinofuranose and galactofuranose residues. These molecules have now found application in biochemical, immunological, and structural biology investigations, which have shed light on their biosynthesis and how these motifs are recognized by both the innate and adaptive immune systems. More recently, attention has been directed toward the synthesis of another class of immunologically active mycobacterial cell wall glycans, the extractable glycolipids. In this case, efforts have been primarily on phenolic glycolipids, and the compounds synthesized have been used to evaluate their ability to modulate cytokine release. Over the past 20 years, the use of chemical synthesis to provide increasingly complex glycan structures has provided significant benefit to the burgeoning field of mycobacterial glycobiology. Through the efforts of groups from around the globe, access to these compounds is now possible via relatively straightforward methods. As the pool of mycobacterial glycans continues to grow, so too will our understanding of their role in disease, which will undoubtedly lead to new strategies to prevent or treat mycobacterial infections.
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Affiliation(s)
- Todd L Lowary
- Alberta Glycomics Centre and Department of Chemistry, University of Alberta , Gunning-Lemieux Chemistry Centre, Edmonton, Alberta T6G 2G2, Canada
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15
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Yamatsugu K, Splain RA, Kiessling LL. Fidelity and Promiscuity of a Mycobacterial Glycosyltransferase. J Am Chem Soc 2016; 138:9205-11. [PMID: 27302377 DOI: 10.1021/jacs.6b04481] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Members of the genus Mycobacterium cause devastating human diseases, including tuberculosis. Mycobacterium tuberculosis can resist some antibiotics because of its durable and impermeable cell envelope. This barrier is assembled from saccharide building blocks not found in mammals, including galactofuranose (Galf). Within the cell envelope, Galf residues are linked together to afford an essential polysaccharide, termed the galactan. The formation of this polymer is catalyzed by the glycosyltransferase GlfT2, a processive carbohydrate polymerase, which generates a sequence-specific polysaccharide with alternating regioisomeric β(1-5) and β(1-6) Galf linkages. GlfT2 exhibits high fidelity in linkage formation, as it will terminate polymerization rather than deviate from its linkage pattern. These findings suggest that GlfT2 would prefer an acceptor with a canonical alternating β(1-5) and β(1-6) Galf sequence. To test this hypothesis, we devised a synthetic route to assemble oligosaccharides with natural and non-natural sequences. GlfT2 could elongate each of these acceptors, even those with non-natural linkage patterns. These data indicate that the glycosyltransferase is surprisingly promiscuous in its substrate preferences. However, GlfT2 did favor some substrates: it preferentially acted on those in which the lipid-bearing Galf residue was connected to the sequence by a β(1-6) glycosidic linkage. The finding that the relative positioning of the lipid and the non-reducing end of the acceptor influences substrate selectivity is consistent with a role for the lipid in acceptor binding. The data also suggest that the fidelity of GlfT2 for generating an alternating β(1-5) and β(1-6) pattern of Galf residues arises not from preferential substrate binding but during processive elongation. These observations suggest that inhibiting the action of GlfT2 will afford changes in cell wall structure.
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Affiliation(s)
- Kenzo Yamatsugu
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Rebecca A Splain
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Laura L Kiessling
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States.,Department of Biochemistry, University of Wisconsin-Madison , 433 Babcock Drive, Madison, Wisconsin 53706, United States
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16
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Jankute M, Byng CV, Alderwick LJ, Besra GS. Elucidation of a protein-protein interaction network involved in Corynebacterium glutamicum cell wall biosynthesis as determined by bacterial two-hybrid analysis. Glycoconj J 2015; 31:475-83. [PMID: 25117516 PMCID: PMC4213368 DOI: 10.1007/s10719-014-9549-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Mycobacterium species have a highly complex and unique cell wall that consists of a large macromolecular structure termed the mycolyl-arabinogalactan-peptidoglycan (mAGP) complex. This complex is essential for growth, survival and virulence of the human pathogen Mycobacterium tuberculosis, and is the target of several anti-tubercular drugs. The closely related species Corynebacterium glutamicum has proven useful in the study of orthologous M. tuberculosis genes and proteins involved in mAGP synthesis. This study examines the construction of a protein-protein interaction network for the major cell wall component arabinogalactan in C. glutamicum based on the use of a bacterial two-hybrid system. We have identified twenty-four putative homotypic and heterotypic protein interactions in vivo. Our results demonstrate an association between glycosyltransferases, GlfT1 and AftB, and interaction between the sub-units of decaprenylphosphoribose epimerase, DprE1 and DprE2. These analyses have also shown that AftB interacts with AftA, which catalyzes the addition of the first three arabinose units onto the galactan chain. Both AftA and AftB associate with other arabinofuranosyltransferases, including Emb and AftC, that elongate and branch the arabinan domain. Moreover, a number of proteins involved in arabinogalactan biosynthesis were shown to form dimers or multimers. These findings provide a useful recourse for understanding the biosynthesis and function of the mycobacterial cell wall, as well as providing new therapeutic targets.
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Affiliation(s)
- Monika Jankute
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
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17
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Eppe G, El Bkassiny S, Vincent SP. Galactofuranose Biosynthesis: Discovery, Mechanisms and Therapeutic Relevance. CARBOHYDRATES IN DRUG DESIGN AND DISCOVERY 2015. [DOI: 10.1039/9781849739993-00209] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Galactofuranose, the atypical and thermodynamically disfavored form of d-galactose, has in reality a very old history in chemistry and biochemistry. The purpose of this book chapter is to give an overview on the fundamental aspects of the galactofuranose biosynthesis, from the biological occurrence to the search of inhibitors.
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Affiliation(s)
- Guillaume Eppe
- University of Namur, Département de Chimie, Laboratoire de Chimie Bio-Organique rue de Bruxelles 61 B-5000 Namur Belgium
| | - Sandy El Bkassiny
- University of Namur, Département de Chimie, Laboratoire de Chimie Bio-Organique rue de Bruxelles 61 B-5000 Namur Belgium
| | - Stéphane P. Vincent
- University of Namur, Département de Chimie, Laboratoire de Chimie Bio-Organique rue de Bruxelles 61 B-5000 Namur Belgium
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18
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Dumitrescu L, Eppe G, Tikad A, Pan W, El Bkassiny S, Gurcha SS, Ardá A, Jiménez-Barbero J, Besra GS, Vincent SP. Selectfluor and NFSI exo-glycal fluorination strategies applied to the enhancement of the binding affinity of galactofuranosyltransferase GlfT2 inhibitors. Chemistry 2014; 20:15208-15. [PMID: 25251918 DOI: 10.1002/chem.201404180] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Indexed: 12/31/2022]
Abstract
Two complementary methods for the synthesis of fluorinated exo-glycals have been developed, for which previously no general reaction had been available. First, a Selectfluor-mediated fluorination was optimized after detailed analysis of all the reaction parameters. A dramatic effect of molecular sieves on the course of the reaction was observed. The reaction was generalized with a set of biologically relevant furanosides and pyranosides. A second direct approach involving carbanionic chemistry and the use of N-fluorobenzenesulfonimide (NFSI) was performed and this method gave better diastereoselectivities. Assignment of the Z/E configuration of all the fluorinated exo-glycals was achieved based on the results of HOESY experiments. Furthermore, fluorinated exo-glycal analogues of UDP-galactofuranose were prepared and assayed against GlfT2, which is a key enzyme involved in the cell-wall biosynthesis of major pathogens. The fluorinated exo-glycals proved to be potent inhibitors as compared with a series of C-glycosidic analogues of UDP-Galf, thus demonstrating the double beneficial effect of the exocyclic enol ether functionality and the fluorine atom.
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Affiliation(s)
- Lidia Dumitrescu
- University of Namur (UNamur), Département de Chimie, Laboratoire de Chimie Bio-Organique rue de Bruxelles 61, B-5000 Namur (Belgium), Fax: (+32) 81-72-45-17
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19
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Li J, Lowary TL. Sulfonium ions as inhibitors of the mycobacterial galactofuranosyltransferase GlfT2. MEDCHEMCOMM 2014. [DOI: 10.1039/c4md00067f] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The mycobacterial cell wall possesses a core galactan moiety composed of approximately 30 galactofuranosyl residues attached via alternating β-(1→5) and β-(1→6) linkages.
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Affiliation(s)
- Jing Li
- Alberta Glycomics Centre and Department of Chemistry
- The University of Alberta
- Gunning–Lemieux Chemistry Centre
- Edmonton
- Canada
| | - Todd L. Lowary
- Alberta Glycomics Centre and Department of Chemistry
- The University of Alberta
- Gunning–Lemieux Chemistry Centre
- Edmonton
- Canada
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20
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Snitynsky RB, Lowary TL. Synthesis of nitrogen-containing furanose sugar nucleotides for use as enzymatic probes. Org Lett 2013; 16:212-5. [PMID: 24328953 DOI: 10.1021/ol4032073] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The sugar nucleotides UDP-2-acetamido-2-deoxy-α-D-galactofuranose (UDP-GalfNAc) and UDP-2-azido-2-deoxy-α-D-galactofuranose (UDP-GalfN3) have been synthesized in preparative scale for the first time. These compounds are useful probes for studying the biosynthesis of glycans containing galactofuranose and/or 2-acetamido-2-deoxy-α-D-galactofuranose residues.
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Affiliation(s)
- Ryan B Snitynsky
- Alberta Glycomics Centre and Department of Chemistry, Gunning-Lemieux Chemistry Centre, University of Alberta , Edmonton, Alberta, Canada T6G 2G2
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21
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Zou L, Zheng RB, Lowary TL. Studies on the substrate specificity of a GDP-mannose pyrophosphorylase from Salmonella enterica. Beilstein J Org Chem 2012; 8:1219-26. [PMID: 23019451 PMCID: PMC3458741 DOI: 10.3762/bjoc.8.136] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Accepted: 06/29/2012] [Indexed: 12/30/2022] Open
Abstract
A series of methoxy and deoxy derivatives of mannopyranose-1-phosphate (Manp-1P) were chemically synthesized, and their ability to be converted into the corresponding guanosine diphosphate mannopyranose (GDP-Manp) analogues by a pyrophosphorylase (GDP-ManPP) from Salmonella enterica was studied. Evaluation of methoxy analogues demonstrated that GDP-ManPP is intolerant of bulky substituents at the C-2, C-3, and C-4 positions, in turn suggesting that these positions are buried inside the enzyme active site. Additionally, both the 6-methoxy and 6-deoxy Manp-1P derivatives are good or moderate substrates for GDP-ManPP, thus indicating that the C-6 hydroxy group of the Manp-1P substrate is not required for binding to the enzyme. When taken into consideration with other previously published work, it appears that this enzyme has potential utility for the chemoenzymatic synthesis of GDP-Manp analogues, which are useful probes for studying enzymes that employ this sugar nucleotide as a substrate.
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Affiliation(s)
- Lu Zou
- Alberta Glycomics Centre and Department of Chemistry, The University of Alberta, Edmonton, AB T6G 2G2, Canada
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22
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Wheatley RW, Zheng RB, Richards MR, Lowary TL, Ng KKS. Tetrameric structure of the GlfT2 galactofuranosyltransferase reveals a scaffold for the assembly of mycobacterial Arabinogalactan. J Biol Chem 2012; 287:28132-43. [PMID: 22707726 DOI: 10.1074/jbc.m112.347484] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Biosynthesis of the mycobacterial cell wall relies on the activities of many enzymes, including several glycosyltransferases (GTs). The polymerizing galactofuranosyltransferase GlfT2 (Rv3808c) synthesizes the bulk of the galactan portion of the mycolyl-arabinogalactan complex, which is the largest component of the mycobacterial cell wall. We used x-ray crystallography to determine the 2.45-Å resolution crystal structure of GlfT2, revealing an unprecedented multidomain structure in which an N-terminal β-barrel domain and two primarily α-helical C-terminal domains flank a central GT-A domain. The kidney-shaped protomers assemble into a C(4)-symmetric homotetramer with an open central core and a surface containing exposed hydrophobic and positively charged residues likely involved with membrane binding. The structure of a 3.1-Å resolution complex of GlfT2 with UDP reveals a distinctive mode of nucleotide recognition. In addition, models for the binding of UDP-galactofuranose and acceptor substrates in combination with site-directed mutagenesis and kinetic studies suggest a mechanism that explains the unique ability of GlfT2 to generate alternating β-(1→5) and β-(1→6) glycosidic linkages using a single active site. The topology imposed by docking a tetrameric assembly onto a membrane bilayer also provides novel insights into aspects of processivity and chain length regulation in this and possibly other polymerizing GTs.
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Affiliation(s)
- Robert W Wheatley
- Alberta Glycomics Centre, University of Calgary, Calgary, Alberta T2N 1N4, Canada
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23
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Brown CD, Rusek MS, Kiessling LL. Fluorosugar chain termination agents as probes of the sequence specificity of a carbohydrate polymerase. J Am Chem Soc 2012; 134:6552-5. [PMID: 22458542 PMCID: PMC3338147 DOI: 10.1021/ja301723p] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Naturally occurring carbohydrate polymers are ubiquitous. They are assembled by polymerizing glycosyltransferases, which can generate polysaccharide products with repeating sequence patterns. The fidelity of enzymes of this class is unknown. We report a method for testing the fidelity of carbohydrate polymerase pattern deposition: we synthesized fluorosugar donors and used them as chain termination agents. The requisite nucleotide fluorosugars could be produced from a single intermediate using the Jacobsen catalyst in a kinetically controlled separation of diastereomers. The resulting fluorosugar donors were used by the galactofuranosyltransferase GlfT2 from Mycobacterium tuberculosis, and the data indicate that this enzyme mediates the cell wall galactan production through a sequence-specific polymerization.
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Affiliation(s)
- Christopher D Brown
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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