1
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Kelly SD, Allas MJ, Goodridge LD, Lowary TL, Whitfield C. Structure, biosynthesis and regulation of the T1 antigen, a phase-variable surface polysaccharide conserved in many Salmonella serovars. Nat Commun 2024; 15:6504. [PMID: 39090110 PMCID: PMC11294581 DOI: 10.1038/s41467-024-50957-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Accepted: 07/22/2024] [Indexed: 08/04/2024] Open
Abstract
The bacterial genus Salmonella includes diverse isolates with multiple variations in the structure of the main polysaccharide component (O antigen) of membrane lipopolysaccharides. In addition, some isolates produce a transient (T) antigen, such as the T1 polysaccharide identified in the 1960s in an isolate of Salmonella enterica Paratyphi B. The structure and biosynthesis of the T1 antigen have remained enigmatic. Here, we use biophysical, biochemical and genetic methods to show that the T1 antigen is a complex linear glycan containing tandem homopolymeric domains of galactofuranose and ribofuranose, linked to lipid A-core, like a typical O antigen. T1 is a phase-variable antigen, regulated by recombinational inversion of the promoter upstream of the T1 genetic locus through a mechanism not observed for other bacterial O antigens. The T1 locus is conserved across many Salmonella isolates, but is mutated or absent in most typhoidal serovars and in serovar Enteritidis.
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Affiliation(s)
- Steven D Kelly
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada
| | - Mikel Jason Allas
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
- Institute of Biological Chemistry, Academia Sinica, Nangang, Taipei, Taiwan
| | | | - Todd L Lowary
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada.
- Institute of Biological Chemistry, Academia Sinica, Nangang, Taipei, Taiwan.
- Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan.
| | - Chris Whitfield
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada.
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2
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Ravikumaran KS, Armiento S, De Castro C, Molinaro A, Wilson JC, Grice ID, Peak IR. Characterisation of a capsular polysaccharide from Moraxella nonliquefaciens CCUG 348T. Carbohydr Res 2024; 538:109095. [PMID: 38507941 DOI: 10.1016/j.carres.2024.109095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 02/22/2024] [Accepted: 03/14/2024] [Indexed: 03/22/2024]
Abstract
Moraxella nonliquefaciens is a commensal of the human upper respiratory tract (URT) but on rare occasions is recovered in cases of ocular, septic and pulmonary infections. Hence there is interest in the pathogenic determinants of M. nonliquefaciens, of which outer membrane (OM) structures such as fimbriae and two capsular polysaccharide (CPS) structures, →3)-β-D-GalpNAc-(1→5)-β-Kdop-(2→ and →8)-α-NeuAc-(2→, have been reported in the literature. To further characterise its surface virulence factors, we isolated a novel CPS from M. nonliquefaciens type strain CCUG 348T. This structure was elucidated using NMR data obtained from CPS samples that were subjected to various degrees of mild acid hydrolysis. Together with GLC-MS data, the structure was resolved as a linear polymer composed of two GalfNAc residues consecutively added to Kdo, →3)-β-D-GalfNAc-(1→3)-α-D-GalfNAc-(1→5)-α-(8-OAc)Kdop-(2→. Supporting evidence for this material being CPS was drawn from the proposed CPS biosynthetic locus which encoded a potential GalfNAc transferase, a UDP-GalpNAc mutase for UDP-GalfNAc production and a putative CPS polymerase with predicted GalfNAc and Kdo transferase domains. This study describes a unique CPS composition reported in Moraxella spp. and offers genetic insights into the synthesis and expression of GalfNAc residues, which are rare in bacterial OM glycans.
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Affiliation(s)
- Kosala S Ravikumaran
- School of Pharmacy and Medical Science, Griffith University, Gold Coast Campus, Queensland, 4222, Australia
| | - Samantha Armiento
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126, Napoli, Italy
| | - Cristina De Castro
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126, Napoli, Italy
| | - Antonio Molinaro
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126, Napoli, Italy
| | - Jennifer C Wilson
- School of Pharmacy and Medical Science, Griffith University, Gold Coast Campus, Queensland, 4222, Australia
| | - I Darren Grice
- School of Pharmacy and Medical Science, Griffith University, Gold Coast Campus, Queensland, 4222, Australia; Institute for Glycomics, Griffith University, Gold Coast Campus, Queensland, 4222, Australia.
| | - Ian R Peak
- School of Pharmacy and Medical Science, Griffith University, Gold Coast Campus, Queensland, 4222, Australia; Institute for Glycomics, Griffith University, Gold Coast Campus, Queensland, 4222, Australia.
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3
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Savková K, Danchenko M, Fabianová V, Bellová J, Bencúrová M, Huszár S, Korduláková J, Siváková B, Baráth P, Mikušová K. Compartmentalization of galactan biosynthesis in mycobacteria. J Biol Chem 2024; 300:105768. [PMID: 38367664 PMCID: PMC10951656 DOI: 10.1016/j.jbc.2024.105768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 01/31/2024] [Accepted: 02/12/2024] [Indexed: 02/19/2024] Open
Abstract
Galactan polymer is a prominent component of the mycobacterial cell wall core. Its biogenesis starts at the cytoplasmic side of the plasma membrane by a build-up of the linker disaccharide [rhamnosyl (Rha) - N-acetyl-glucosaminyl (GlcNAc) phosphate] on the decaprenyl-phosphate carrier. This decaprenyl-P-P-GlcNAc-Rha intermediate is extended by two bifunctional galactosyl transferases, GlfT1 and GlfT2, and then it is translocated to the periplasmic space by an ABC transporter Wzm-Wzt. The cell wall core synthesis is finalized by the action of an array of arabinosyl transferases, mycolyl transferases, and ligases that catalyze an attachment of the arabinogalactan polymer to peptidoglycan through the linker region. Based on visualization of the GlfT2 enzyme fused with fluorescent tags it was proposed that galactan polymerization takes place in a specific compartment of the mycobacterial cell envelope, the intracellular membrane domain, representing pure plasma membrane free of cell wall components (previously denoted as the "PMf" domain), which localizes to the polar region of mycobacteria. In this work, we examined the activity of the galactan-producing cellular machine in the cell-wall containing cell envelope fraction and in the cell wall-free plasma membrane fraction prepared from Mycobacterium smegmatis by the enzyme assays using radioactively labeled substrate UDP-[14C]-galactose as a tracer. We found that despite a high abundance of GlfT2 in both of these fractions as confirmed by their thorough proteomic analyses, galactan is produced only in the reaction mixtures containing the cell wall components. Our findings open the discussion about the distribution of GlfT2 and the regulation of its activity in mycobacteria.
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Affiliation(s)
- Karin Savková
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Bratislava, Slovakia
| | - Maksym Danchenko
- Institute of Chemistry, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Viktória Fabianová
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Bratislava, Slovakia
| | - Jana Bellová
- Institute of Chemistry, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Mária Bencúrová
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Bratislava, Slovakia
| | - Stanislav Huszár
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Bratislava, Slovakia
| | - Jana Korduláková
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Bratislava, Slovakia
| | - Barbara Siváková
- Institute of Chemistry, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Peter Baráth
- Institute of Chemistry, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Katarína Mikušová
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Bratislava, Slovakia.
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4
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Primo LMDG, Roque-Borda CA, Carnero Canales CS, Caruso IP, de Lourenço IO, Colturato VMM, Sábio RM, de Melo FA, Vicente EF, Chorilli M, da Silva Barud H, Barbugli PA, Franzyk H, Hansen PR, Pavan FR. Antimicrobial peptides grafted onto the surface of N-acetylcysteine-chitosan nanoparticles can revitalize drugs against clinical isolates of Mycobacterium tuberculosis. Carbohydr Polym 2024; 323:121449. [PMID: 37940311 DOI: 10.1016/j.carbpol.2023.121449] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 09/21/2023] [Accepted: 09/28/2023] [Indexed: 11/10/2023]
Abstract
Tuberculosis is caused by Mycobacterium tuberculosis (MTB) and is the leading cause of death from infectious diseases in the World. The search for new antituberculosis drugs is a high priority, since several drug-resistant TB-strains have emerged. Many nanotechnology strategies are being explored to repurpose or revive drugs. An interesting approach is to graft antimicrobial peptides (AMPs) to antibiotic-loaded nanoparticles. The objective of the present work was to determine the anti-MTB activity of rifampicin-loaded N-acetylcysteine-chitosan-based nanoparticles (NPs), conjugated with the AMP Ctx(Ile21)-Ha; against clinical isolates (multi- and extensively-drug resistant) and the H37Rv strain. The modified chitosan and drug-loaded NPs were characterized with respect to their physicochemical stability and their antimycobacterial profile, which showed potent inhibition (MIC values <0.977 μg/mL) by the latter. Furthermore, their accumulation within macrophages and cytotoxicity were determined. To understand the possible mechanisms of action, an in silico study of the peptide against MTB membrane receptors was performed. The results presented herein demonstrate that antibiotic-loaded NPs grafted with an AMP can be a powerful tool for revitalizing drugs against multidrug-resistant M. tuberculosis strains, by launching multiple attacks against MTB. This approach could potentially serve as a novel treatment strategy for various long-term diseases requiring extended treatment periods.
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Affiliation(s)
- Laura Maria Duran Gleriani Primo
- São Paulo State University (UNESP), Tuberculosis Research Laboratory, School of Pharmaceutical Sciences, Araraquara, São Paulo, Brazil
| | - Cesar Augusto Roque-Borda
- São Paulo State University (UNESP), Tuberculosis Research Laboratory, School of Pharmaceutical Sciences, Araraquara, São Paulo, Brazil; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Christian Shleider Carnero Canales
- Vicerrectorado de Investigación, Facultad de Ciencias Farmacéuticas bioquímicas y biotecnológicas, Universidad Católica de Santa María, Arequipa, Peru
| | - Icaro Putinhon Caruso
- Department of Physics - Institute of Biosciences, Humanities and Exact Sciences (IBILCE), São Paulo State University (UNESP), 15054-000 São José do Rio Preto, São Paulo, Brazil
| | - Isabella Ottenio de Lourenço
- Department of Physics - Institute of Biosciences, Humanities and Exact Sciences (IBILCE), São Paulo State University (UNESP), 15054-000 São José do Rio Preto, São Paulo, Brazil
| | - Vitória Maria Medalha Colturato
- Department of Biotechnology, Laboratory of Polymers and Biomaterials, University of Araraquara (UNIARA), Araraquara, São Paulo, Brazil
| | - Rafael Miguel Sábio
- São Paulo State University (UNESP), Department of Drug and Medicines, School of Pharmaceutical Sciences, Araraquara, São Paulo, Brazil
| | - Fernando Alves de Melo
- Department of Physics - Institute of Biosciences, Humanities and Exact Sciences (IBILCE), São Paulo State University (UNESP), 15054-000 São José do Rio Preto, São Paulo, Brazil
| | - Eduardo Festozo Vicente
- School of Sciences and Engineering, São Paulo State University (UNESP), Tupã, São Paulo, Brazil
| | - Marlus Chorilli
- São Paulo State University (UNESP), Department of Drug and Medicines, School of Pharmaceutical Sciences, Araraquara, São Paulo, Brazil
| | - Hernane da Silva Barud
- Department of Biotechnology, Laboratory of Polymers and Biomaterials, University of Araraquara (UNIARA), Araraquara, São Paulo, Brazil
| | - Paula Aboud Barbugli
- Department of Dental Materials and Prosthodontics, School of Dentistry, Sao Paulo State University (UNESP), Araraquara, São Paulo, Brazil
| | - Henrik Franzyk
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Paul Robert Hansen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Fernando Rogério Pavan
- São Paulo State University (UNESP), Tuberculosis Research Laboratory, School of Pharmaceutical Sciences, Araraquara, São Paulo, Brazil.
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5
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Taylor KI, Ho JS, Trial HO, Carter AW, Kiessling LL. Assessing Squarates as Amine-Reactive Probes. J Am Chem Soc 2023; 145:25056-25060. [PMID: 37938802 PMCID: PMC10935565 DOI: 10.1021/jacs.2c05691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2023]
Abstract
Probes that covalently label protein targets facilitate the identification of ligand-binding sites. Lysine residues are prevalent in the proteome, making them attractive substrates for covalent probes. However, identifying electrophiles that undergo amine-specific, regioselective reactions with binding site lysine residues is challenging. Squarates can engage in two sequential conjugate addition-elimination reactions with amines. Nitrogen donation reduces the second reaction rate, making the mono squaramide a mild electrophile. We postulated that this mild electrophilicity would demand a longer residence time near the amine, affording higher selectivity for binding site lysines. Therefore, we compared the kinetics of squarate and monosquaramide amine substitution to alternative amine bioconjugation handles. The data revealed that N-hydroxy succinimidyl esters react 4 orders of magnitude faster, consistent with their labeling promiscuity. Squarate reactivity can be tuned by a substitution pattern. Electron-withdrawing groups on the vinylogous ester or amide increase reaction rates. Dithionosquarates react more rapidly than squarates, while vinylogous thioester analogs, dithiosquarates, react more slowly. We assessed squarate selectively using the UDP-sugar processing enzyme GlfT2 from Mycobacterium tuberculosis, which possesses 21 surface-exposed lysines. The reaction predominately modified one lysine proximal to a binding site to afford covalent inhibition. These findings demonstrate the selectivity of squaric esters and squaramides, which is a critical feature for affinity-based chemoproteomic probes.
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Affiliation(s)
- Katherine I. Taylor
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, United States
| | - Jordan S. Ho
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, United States
| | - Hallie O. Trial
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, United States
| | - Alan W. Carter
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, United States
| | - Laura L. Kiessling
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, United States
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6
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Du X, Chu X, Liu N, Jia X, Peng H, Xiao Y, Liu L, Yu H, Li F, He C. Structures of the NDP-pyranose mutase belonging to glycosyltransferase family 75 reveal residues important for Mn 2+ coordination and substrate binding. J Biol Chem 2023; 299:102903. [PMID: 36642179 PMCID: PMC9937993 DOI: 10.1016/j.jbc.2023.102903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 12/29/2022] [Accepted: 01/02/2023] [Indexed: 01/15/2023] Open
Abstract
Members of glycosyltransferase family 75 (GT75) not only reversibly catalyze the autoglycosylation of a conserved arginine residue with specific NDP-sugars but also exhibit NDP-pyranose mutase activity that reversibly converts specific NDP-pyranose to NDP-furanose. The latter activity provides valuable NDP-furanosyl donors for glycosyltransferases and requires a divalent cation as a cofactor instead of FAD used by UDP-D-galactopyranose mutase. However, details of the mechanism for NDP-pyranose mutase activity are not clear. Here we report the first crystal structures of GT75 family NDP-pyranose mutases. The novel structures of GT75 member MtdL in complex with Mn2+ and GDP, GDP-D-glucopyranose, GDP-L-fucopyranose, GDP-L-fucofuranose, respectively, combined with site-directed mutagenesis studies, reveal key residues involved in Mn2+ coordination, substrate binding, and catalytic reactions. We also provide a possible catalytic mechanism for this unique type of NDP-pyranose mutase. Taken together, our results highlight key elements of an enzyme family important for furanose biosynthesis.
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Affiliation(s)
- Xueqing Du
- Anhui Key Laboratory of Modern Biomanufacturing and School of Life Sciences, Anhui University, Hefei, Anhui, China
| | - Xuan Chu
- Anhui Key Laboratory of Modern Biomanufacturing and School of Life Sciences, Anhui University, Hefei, Anhui, China
| | - Ning Liu
- Anhui Key Laboratory of Modern Biomanufacturing and School of Life Sciences, Anhui University, Hefei, Anhui, China
| | - Xiaoyu Jia
- Anhui Key Laboratory of Modern Biomanufacturing and School of Life Sciences, Anhui University, Hefei, Anhui, China
| | - Hui Peng
- Anhui Key Laboratory of Modern Biomanufacturing and School of Life Sciences, Anhui University, Hefei, Anhui, China
| | - Yazhong Xiao
- Anhui Key Laboratory of Modern Biomanufacturing and School of Life Sciences, Anhui University, Hefei, Anhui, China
| | - Lin Liu
- Anhui Key Laboratory of Modern Biomanufacturing and School of Life Sciences, Anhui University, Hefei, Anhui, China
| | - Haizhu Yu
- Department of Chemistry and Centre for Atomic Engineering of Advanced Materials, Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials, Anhui University, Hefei, China
| | - Fudong Li
- MOE Key Laboratory for Cellular Dynamics, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Chao He
- Anhui Key Laboratory of Modern Biomanufacturing and School of Life Sciences, Anhui University, Hefei, Anhui, China.
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7
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Chi C, Xu R, Chen Q, Zhang X, Shi X, Jin H, Yin F, Jia H, Zhang L, Yang D, Ju J, Li Q, Ma M. Structural Insight into a Metal-Dependent Mutase Revealing an Arginine Residue-Covalently Mediated Interconversion between Nucleotide-Based Pyranose and Furanose. ACS Catal 2023. [DOI: 10.1021/acscatal.2c04907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Changbiao Chi
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Haidian District, Beijing 100191, China
| | - Run Xu
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China
| | - Qianqian Chen
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Haidian District, Beijing 100191, China
| | - Xiaohui Zhang
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Haidian District, Beijing 100191, China
| | - Xiaomeng Shi
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Haidian District, Beijing 100191, China
| | - Hongwei Jin
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Haidian District, Beijing 100191, China
| | - Fuling Yin
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Haidian District, Beijing 100191, China
| | - Hongli Jia
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Haidian District, Beijing 100191, China
| | - Liangren Zhang
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Haidian District, Beijing 100191, China
| | - Donghui Yang
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Haidian District, Beijing 100191, China
| | - Jianhua Ju
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China
| | - Qinglian Li
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China
| | - Ming Ma
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Haidian District, Beijing 100191, China
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8
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Fittolani G, Tyrikos-Ergas T, Vargová D, Chaube MA, Delbianco M. Progress and challenges in the synthesis of sequence controlled polysaccharides. Beilstein J Org Chem 2021; 17:1981-2025. [PMID: 34386106 PMCID: PMC8353590 DOI: 10.3762/bjoc.17.129] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 07/22/2021] [Indexed: 01/15/2023] Open
Abstract
The sequence, length and substitution of a polysaccharide influence its physical and biological properties. Thus, sequence controlled polysaccharides are important targets to establish structure-properties correlations. Polymerization techniques and enzymatic methods have been optimized to obtain samples with well-defined substitution patterns and narrow molecular weight distribution. Chemical synthesis has granted access to polysaccharides with full control over the length. Here, we review the progress towards the synthesis of well-defined polysaccharides. For each class of polysaccharides, we discuss the available synthetic approaches and their current limitations.
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Affiliation(s)
- Giulio Fittolani
- Department of Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476 Potsdam, Germany
- Department of Chemistry and Biochemistry, Freie Universität Berlin, Arnimallee 22, 14195 Berlin, Germany
| | - Theodore Tyrikos-Ergas
- Department of Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476 Potsdam, Germany
- Department of Chemistry and Biochemistry, Freie Universität Berlin, Arnimallee 22, 14195 Berlin, Germany
| | - Denisa Vargová
- Department of Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Manishkumar A Chaube
- Department of Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Martina Delbianco
- Department of Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476 Potsdam, Germany
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9
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Abstract
Iminosugars are naturally occurring carbohydrate analogues known since 1967. These natural compounds and hundreds of their synthetic derivatives prepared over five decades have been mainly exploited to inhibit the glycosidases, the enzymes catalysing the glycosidic bond cleavage, in order to find new drugs for the treatment of type 2 diabetes and other diseases. However, iminosugars are also inhibitors of glycosyltransferases, the enzymes responsible for the synthesis of oligosaccharides and glycoconjugates. The selective inhibition of specific glycosyltransferases involved in cancer or bacterial infections could lead to innovative therapeutic agents. The synthesis and biological properties of all the iminosugars assayed to date as glycosyltransferase inhibitors are reviewed in the present article.
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Affiliation(s)
- Irene Conforti
- Institut des Biomolécules Max Mousseron (IBMM), UMR 5247, CNRS, Université de Montpellier, Ecole Nationale Supérieure de Chimie de Montpellier, 8 Rue de l'Ecole Normale, 34296 Montpellier cedex 5, France.
| | - Alberto Marra
- Institut des Biomolécules Max Mousseron (IBMM), UMR 5247, CNRS, Université de Montpellier, Ecole Nationale Supérieure de Chimie de Montpellier, 8 Rue de l'Ecole Normale, 34296 Montpellier cedex 5, France.
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10
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An ABC transporter Wzm-Wzt catalyzes translocation of lipid-linked galactan across the plasma membrane in mycobacteria. Proc Natl Acad Sci U S A 2021; 118:2023663118. [PMID: 33879617 DOI: 10.1073/pnas.2023663118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Mycobacterium tuberculosis, one of the deadliest pathogens in human history, is distinguished by a unique, multilayered cell wall, which offers the bacterium a high level of protection from the attacks of the host immune system. The primary structure of the cell wall core, composed of covalently linked peptidoglycan, branched heteropolysaccharide arabinogalactan, and mycolic acids, is well known, and numerous enzymes involved in the biosynthesis of its components are characterized. The cell wall biogenesis takes place at both cytoplasmic and periplasmic faces of the plasma membrane, and only recently some of the specific transport systems translocating the metabolic intermediates between these two compartments have been characterized [M. Jackson, C. M. Stevens, L. Zhang, H. I. Zgurskaya, M. Niederweis, Chem. Rev., 10.1021/acs.chemrev.0c00869 (2020)]. In this work, we use CRISPR interference methodology in Mycobacterium smegmatis to functionally characterize an ATP-binding cassette (ABC) transporter involved in the translocation of galactan precursors across the plasma membrane. We show that genetic knockdown of the transmembrane subunit of the transporter results in severe morphological changes and the accumulation of an aberrantly long galactan precursor. Based on similarities with structures and functions of specific O-antigen ABC transporters of gram-negative bacteria [C. Whitfield, D. M. Williams, S. D. Kelly, J. Biol. Chem. 295, 10593-10609 (2020)], we propose a model for coupled synthesis and export of the galactan polymer precursor in mycobacteria.
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11
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Involvement of a multifunctional rhamnosyltransferase in the synthesis of three related Acinetobacter baumannii capsular polysaccharides, K55, K74 and K85. Int J Biol Macromol 2020; 166:1230-1237. [PMID: 33159946 DOI: 10.1016/j.ijbiomac.2020.11.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 07/22/2020] [Accepted: 11/02/2020] [Indexed: 12/17/2022]
Abstract
KL55, KL74, and KL85 capsular polysaccharide (CPS) biosynthesis loci in Acinetobacter baumannii BAL_204, BAL_309, and LUH5543 genomes, respectively, are related and each contains genes for l-Rhap and d-GlcpA synthesis. The CPSs were isolated and studied by sugar analysis, Smith degradation, and 1H and 13C NMR spectroscopy. The K55 and K74 CPSs are built up of branched octasaccharide repeats (K units) containing one residue each of d-GlcpA and d-GlcpNAc and six residues of l-Rhap. The K55 unit differs from the K74 unit in the linkage between D-GlcpA and an l-Rhap residue in the K unit (1 → 3 versus 1 → 2) and linkage between K units. However, most K units in the isolated K74 CPS were modified by β-elimination of a side-chain α-l-Rhap-(1 → 3)-α-l-Rhap disaccharide from position 4 of GlcA to give 4-deoxy-l-threo-hex-4-enuronic acid (1:~3 ratio of intact and modified units). The K85 CPS has a branched heptasaccharide K unit similar to the K74 unit but with one fewer α-l-Rhap residue in the side chain. In contrast to previous findings on A. baumannii CPSs, each K locus includes fewer glycosyltransferase (Gtr) genes than the number required to form all linkages in the K units. Hence, one Gtr appears to be multifunctional catalysing formation of two 1 → 2 and one 1 → 3 linkages between the l-Rha residues.
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12
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Justen AM, Hodges HL, Kim LM, Sadecki PW, Porfirio S, Ultee E, Black I, Chung GS, Briegel A, Azadi P, Kiessling LL. Polysaccharide length affects mycobacterial cell shape and antibiotic susceptibility. SCIENCE ADVANCES 2020; 6:6/38/eaba4015. [PMID: 32938674 PMCID: PMC7494350 DOI: 10.1126/sciadv.aba4015] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 08/05/2020] [Indexed: 05/04/2023]
Abstract
Bacteria control the length of their polysaccharides, which can control cell viability, physiology, virulence, and immune evasion. Polysaccharide chain length affects immunomodulation, but its impact on bacterial physiology and antibiotic susceptibility was unclear. We probed the consequences of truncating the mycobacterial galactan, an essential linear polysaccharide of about 30 residues. Galactan covalently bridges cell envelope layers, with the outermost cell wall linkage point occurring at residue 12. Reducing galactan chain length by approximately half compromises fitness, alters cell morphology, and increases the potency of hydrophobic antibiotics. Systematic variation of the galactan chain length revealed that it determines periplasm size. Thus, glycan chain length can directly affect cellular physiology and antibiotic activity, and mycobacterial glycans, not proteins, regulate periplasm size.
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Affiliation(s)
- Alexander M Justen
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139, USA
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706-1544, USA
| | - Heather L Hodges
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706-1322, USA
| | - Lili M Kim
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706-1544, USA
| | - Patric W Sadecki
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706-1322, USA
| | - Sara Porfirio
- Complex Carbohydrate Research Center, 315 Riverbend Rd, Athens, GA 30602, USA
| | - Eveline Ultee
- Institute of Biology, University of Leiden, 2333 BE Leiden, Netherlands
| | - Ian Black
- Complex Carbohydrate Research Center, 315 Riverbend Rd, Athens, GA 30602, USA
| | - Grace S Chung
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706-1544, USA
| | - Ariane Briegel
- Institute of Biology, University of Leiden, 2333 BE Leiden, Netherlands
| | - Parastoo Azadi
- Complex Carbohydrate Research Center, 315 Riverbend Rd, Athens, GA 30602, USA
| | - Laura L Kiessling
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139, USA.
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706-1544, USA
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706-1322, USA
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
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13
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Janoš P, Tvaroška I, Dellago C, Koča J. Catalytic Mechanism of Processive GlfT2: Transition Path Sampling Investigation of Substrate Translocation. ACS OMEGA 2020; 5:21374-21384. [PMID: 32905330 PMCID: PMC7469130 DOI: 10.1021/acsomega.0c01434] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 07/29/2020] [Indexed: 06/11/2023]
Abstract
We applied the transition path sampling (TPS) method to study the translocation step of the catalytic mechanism of galactofuranosyl transferase 2 (GlfT2). Using TPS in the field of enzymatic reactions is still relatively rare, and we show its effectiveness on this enzymatic system. We decipher an unknown mechanism of the translocation step and, thus, provide a complete understanding of the catalytic mechanism of GlfT2 at the atomistic level. The GlfT2 enzyme is involved in the formation of the mycobacterial cell wall and transfers galactofuranose (Galf) from UDP-Galf onto a growing acceptor Galf chain. The biosynthesis of the galactan chain is accomplished in a processive manner, with the growing acceptor substrate remaining bound to GlfT2. The glycosidic bond formed by GlfT2 between the two Galf residues alternates between β-(1-6) and β-(1-5) linkages. The translocation of the growing galactan between individual additions of Galf residues is crucial for the function of GlfT2. Analysis of unbiased trajectory ensembles revealed that the translocation proceeds differently depending on the glycosidic linkage between the last two Galf residues. We also showed that the protonation state of the catalytic residue Asp372 significantly influences the translocation. Approximate transition state structures and potential energy reaction barriers of the translocation process were determined. The calculated potential reaction barriers in the range of 6-14 kcal/mol show that the translocation process is not the rate-limiting step in galactan biosynthesis.
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Affiliation(s)
- Pavel Janoš
- Central
European Institute of Technology (CEITEC), Masaryk University, Brno 601 77, Czech Republic
- Faculty
of Science, National Centre for Biomolecular Research, Masaryk University, Brno 601 77, Czech Republic
| | - Igor Tvaroška
- Central
European Institute of Technology (CEITEC), Masaryk University, Brno 601 77, Czech Republic
- Institute
of Chemistry, Slovak Academy of Sciences, Bratislava 84536, Slovak Republic
| | | | - Jaroslav Koča
- Central
European Institute of Technology (CEITEC), Masaryk University, Brno 601 77, Czech Republic
- Faculty
of Science, National Centre for Biomolecular Research, Masaryk University, Brno 601 77, Czech Republic
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14
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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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15
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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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16
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A bifunctional O-antigen polymerase structure reveals a new glycosyltransferase family. Nat Chem Biol 2020; 16:450-457. [DOI: 10.1038/s41589-020-0494-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 02/05/2020] [Indexed: 02/07/2023]
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17
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Abstract
Extracellular polysaccharides and glycoproteins of pathogenic bacteria assist in adherence, autoaggregation, biofilm formation, and host immune system evasion. As a result, considerable research in the field of glycobiology is dedicated to study the composition and function of glycans associated with virulence, as well as the enzymes involved in their biosynthesis with the aim to identify novel antibiotic targets. Especially, insights into the enzyme mechanism, substrate binding, and transition-state structures are valuable as a starting point for rational inhibitor design. An intriguing aspect of enzymes that generate or process polysaccharides and glycoproteins is the level of processivity. The existence of enzymatic processivity reflects the need for regulation of the final glycan/glycoprotein length and structure, depending on the role they perform. In this Review, we describe the currently reported examples of various processive enzymes involved in polymerization and transfer of sugar moieties, predominantly in bacterial pathogens, with a focus on the biochemical methods, to showcase the importance of studying processivity for understanding the mechanism.
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Affiliation(s)
- Liubov Yakovlieva
- Stratingh Institute for Chemistry, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Marthe T. C. Walvoort
- Stratingh Institute for Chemistry, University of Groningen, 9747 AG Groningen, The Netherlands
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18
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Biosynthesis of Galactan in Mycobacterium tuberculosis as a Viable TB Drug Target? Antibiotics (Basel) 2020; 9:antibiotics9010020. [PMID: 31935842 PMCID: PMC7168186 DOI: 10.3390/antibiotics9010020] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 12/27/2019] [Accepted: 01/02/2020] [Indexed: 12/21/2022] Open
Abstract
While target-based drug design has proved successful in several therapeutic areas, this approach has not yet provided compelling outcomes in the field of antibacterial agents. This statement remains especially true for the development of novel therapeutic interventions against tuberculosis, an infectious disease that is among the top ten leading causes of death globally. Mycobacterial galactan is an important component of the protective cell wall core of the tuberculosis pathogen and it could provide a promising target for the design of new drugs. In this review, we summarize the current knowledge on galactan biosynthesis in Mycobacterium tuberculosis, including landmark findings that led to the discovery and understanding of three key enzymes in this pathway: UDP-galactose mutase, and galactofuranosyl transferases GlfT1 and GlfT2. Moreover, we recapitulate the efforts aimed at their inhibition. The predicted common transition states of the three enzymes provide the lucrative possibility of multitargeting in pharmaceutical development, a favourable property in the mitigation of drug resistance. We believe that a tight interplay between target-based computational approaches and experimental methods will result in the development of original inhibitors that could serve as the basis of a new generation of drugs against tuberculosis.
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19
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Bettencourt P, Müller J, Nicastri A, Cantillon D, Madhavan M, Charles PD, Fotso CB, Wittenberg R, Bull N, Pinpathomrat N, Waddell SJ, Stylianou E, Hill AVS, Ternette N, McShane H. Identification of antigens presented by MHC for vaccines against tuberculosis. NPJ Vaccines 2020; 5:2. [PMID: 31908851 PMCID: PMC6941960 DOI: 10.1038/s41541-019-0148-y] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 11/25/2019] [Indexed: 11/09/2022] Open
Abstract
Mycobacterium tuberculosis (M.tb) is responsible for more deaths globally than any other pathogen. The only available vaccine, bacillus Calmette-Guérin (BCG), has variable efficacy throughout the world. A more effective vaccine is urgently needed. The immune response against tuberculosis relies, at least in part, on CD4+ T cells. Protective vaccines require the induction of antigen-specific CD4+ T cells via mycobacterial peptides presented by MHC class-II in infected macrophages. In order to identify mycobacterial antigens bound to MHC, we have immunoprecipitated MHC class-I and class-II complexes from THP-1 macrophages infected with BCG, purified MHC class-I and MHC class-II peptides and analysed them by liquid chromatography tandem mass spectrometry. We have successfully identified 94 mycobacterial peptides presented by MHC-II and 43 presented by MHC-I, from 76 and 41 antigens, respectively. These antigens were found to be highly expressed in infected macrophages. Gene ontology analysis suggests most of these antigens are associated with membranes and involved in lipid biosynthesis and transport. The sequences of selected peptides were confirmed by spectral match validation and immunogenicity evaluated by IFN-gamma ELISpot against peripheral blood mononuclear cell from volunteers vaccinated with BCG, M.tb latently infected subjects or patients with tuberculosis disease. Three antigens were expressed in viral vectors, and evaluated as vaccine candidates alone or in combination in a murine aerosol M.tb challenge model. When delivered in combination, the three candidate vaccines conferred significant protection in the lungs and spleen compared with BCG alone, demonstrating proof-of-concept for this unbiased approach to identifying new candidate antigens. Protective vaccines against Mycobacterium tuberculosis (M.tb), such as bacillus Calmette-Guérin (BCG), trigger strong CD4 T-cell responses specific to mycobacterium peptides, but their efficacy is variable. Paulo Bettencourt and colleagues now identify a set of mycobacterium peptides presented by BCG-infected macrophages via major compatibility complexes (MHC), and show that three of these antigens can be combined to formulate a vaccine that confers improved protection to Mtb infection in mice. After identifying 94 MHC-II-associated and 43 MHC-I-associated mycobacterium peptides, the researchers performed immunogenicity assays with peripheral blood mononuclear cells from BCG-vaccinated donors, latent Mtb-infected patients and patients with tuberculosis, and show that a set of these peptides was recognised by the immune cells, validating their potential as possible components for new Mtb vaccine formulations. These findings further support the value of immunopeptidomics for the identification of new antigens for effective vaccine alternatives.
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Affiliation(s)
| | - Julius Müller
- 1Jenner Institute, University of Oxford, Oxford, OX3 7DQ UK
| | - Annalisa Nicastri
- 2Target Discovery Institute, University of Oxford, Oxford, OX3 7FZ UK
| | - Daire Cantillon
- 3Department of Global Health and Infection, Brighton and Sussex Medical School, University of Sussex, Brighton, BN1 9PX UK
| | - Meera Madhavan
- 1Jenner Institute, University of Oxford, Oxford, OX3 7DQ UK
| | - Philip D Charles
- 2Target Discovery Institute, University of Oxford, Oxford, OX3 7FZ UK
| | - Carine B Fotso
- 1Jenner Institute, University of Oxford, Oxford, OX3 7DQ UK
| | | | - Naomi Bull
- 1Jenner Institute, University of Oxford, Oxford, OX3 7DQ UK
| | | | - Simon J Waddell
- 3Department of Global Health and Infection, Brighton and Sussex Medical School, University of Sussex, Brighton, BN1 9PX UK
| | | | | | - Nicola Ternette
- 1Jenner Institute, University of Oxford, Oxford, OX3 7DQ UK.,2Target Discovery Institute, University of Oxford, Oxford, OX3 7FZ UK
| | - Helen McShane
- 1Jenner Institute, University of Oxford, Oxford, OX3 7DQ UK
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20
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Ortiz CLD, Completo GC, Nacario RC, Nellas RB. Potential Inhibitors of Galactofuranosyltransferase 2 (GlfT2): Molecular Docking, 3D-QSAR, and In Silico ADMETox Studies. Sci Rep 2019; 9:17096. [PMID: 31745103 PMCID: PMC6863818 DOI: 10.1038/s41598-019-52764-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 10/01/2019] [Indexed: 11/08/2022] Open
Abstract
A strategy in the discovery of anti-tuberculosis (anti-TB) drug involves targeting the enzymes involved in the biosynthesis of Mycobacterium tuberculosis' (Mtb) cell wall. One of these enzymes is Galactofuranosyltransferase 2 (GlfT2) that catalyzes the elongation of the galactan chain of Mtb cell wall. Studies targeting GlfT2 have so far produced compounds showing minimal inhibitory activity. With the current challenge of designing potential GlfT2 inhibitors with high inhibition activity, computational methods such as molecular docking, receptor-ligand mapping, molecular dynamics, and Three-Dimensional-Quantitative Structure-Activity Relationship (3D-QSAR) were utilized to deduce the interactions of the reported compounds with the target enzyme and enabling the design of more potent GlfT2 inhibitors. Molecular docking studies showed that the synthesized compounds have binding energy values between -3.00 to -6.00 kcal mol-1. Two compounds, #27 and #31, have registered binding energy values of -8.32 ± 0.01, and -8.08 ± 0.01 kcal mol-1, respectively. These compounds were synthesized as UDP-Galactopyranose mutase (UGM) inhibitors and could possibly inhibit GlfT2. Interestingly, the analogs of the known disaccharide substrate, compounds #1-4, have binding energy range of -10.00 to -19.00 kcal mol-1. The synthesized and newly designed compounds were subjected to 3D-QSAR to further design compounds with effective interaction within the active site. Results showed improved binding energy from -6.00 to -8.00 kcal mol-1. A significant increase on the binding affinity was observed when modifying the aglycon part instead of the sugar moiety. Furthermore, these top hit compounds were subjected to in silico ADMETox evaluation. Compounds #31, #70, #71, #72, and #73 were found to pass the ADME evaluation and throughout the screening, only compound #31 passed the predicted toxicity evaluation. This work could pave the way in the design and synthesis of GlfT2 inhibitors through computer-aided drug design and can be used as an initial approach in identifying potential novel GlfT2 inhibitors with promising activity and low toxicity.
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Affiliation(s)
- Christopher Llynard D Ortiz
- Institute of Chemistry, College of Arts and Sciences, University of the Philippines Los Banos, College, Laguna, 4031, Philippines
- Institute of Chemistry, College of Science, University of the Philippines Diliman, Diliman, Quezon City, 1101, Philippines
| | - Gladys C Completo
- Institute of Chemistry, College of Arts and Sciences, University of the Philippines Los Banos, College, Laguna, 4031, Philippines
| | - Ruel C Nacario
- Institute of Chemistry, College of Arts and Sciences, University of the Philippines Los Banos, College, Laguna, 4031, Philippines
| | - Ricky B Nellas
- Institute of Chemistry, College of Science, University of the Philippines Diliman, Diliman, Quezon City, 1101, Philippines.
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21
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Breuer M, Earnest TM, Merryman C, Wise KS, Sun L, Lynott MR, Hutchison CA, Smith HO, Lapek JD, Gonzalez DJ, de Crécy-Lagard V, Haas D, Hanson AD, Labhsetwar P, Glass JI, Luthey-Schulten Z. Essential metabolism for a minimal cell. eLife 2019; 8:36842. [PMID: 30657448 PMCID: PMC6609329 DOI: 10.7554/elife.36842] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 01/17/2019] [Indexed: 11/29/2022] Open
Abstract
JCVI-syn3A, a robust minimal cell with a 543 kbp genome and 493 genes, provides a versatile platform to study the basics of life. Using the vast amount of experimental information available on its precursor, Mycoplasma mycoides capri, we assembled a near-complete metabolic network with 98% of enzymatic reactions supported by annotation or experiment. The model agrees well with genome-scale in vivo transposon mutagenesis experiments, showing a Matthews correlation coefficient of 0.59. The genes in the reconstruction have a high in vivo essentiality or quasi-essentiality of 92% (68% essential), compared to 79% in silico essentiality. This coherent model of the minimal metabolism in JCVI-syn3A at the same time also points toward specific open questions regarding the minimal genome of JCVI-syn3A, which still contains many genes of generic or completely unclear function. In particular, the model, its comparison to in vivo essentiality and proteomics data yield specific hypotheses on gene functions and metabolic capabilities; and provide suggestions for several further gene removals. In this way, the model and its accompanying data guide future investigations of the minimal cell. Finally, the identification of 30 essential genes with unclear function will motivate the search for new biological mechanisms beyond metabolism. One way that researchers can test whether they understand a biological system is to see if they can accurately recreate it as a computer model. The more they learn about living things, the more the researchers can improve their models and the closer the models become to simulating the original. In this approach, it is best to start by trying to model a simple system. Biologists have previously succeeded in creating ‘minimal bacterial cells’. These synthetic cells contain fewer genes than almost all other living things and they are believed to be among the simplest possible forms of life that can grow on their own. The minimal cells can produce all the chemicals that they need to survive – in other words, they have a metabolism. Accurately recreating one of these cells in a computer is a key first step towards simulating a complete living system. Breuer et al. have developed a computer model to simulate the network of the biochemical reactions going on inside a minimal cell with just 493 genes. By altering the parameters of their model and comparing the results to experimental data, Breuer et al. explored the accuracy of their model. Overall, the model reproduces experimental results, but it is not yet perfect. The differences between the model and the experiments suggest new questions and tests that could advance our understanding of biology. In particular, Breuer et al. identified 30 genes that are essential for life in these cells but that currently have no known purpose. Continuing to develop and expand models like these to reproduce more complex living systems provides a tool to test current knowledge of biology. These models may become so advanced that they could predict how living things will respond to changing situations. This would allow scientists to test ideas sooner and make much faster progress in understanding life on Earth. Ultimately, these models could one day help to accelerate medical and industrial processes to save lives and enhance productivity.
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Affiliation(s)
- Marian Breuer
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, United States
| | - Tyler M Earnest
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, United States
| | | | - Kim S Wise
- J Craig Venter Institute, La Jolla, United States
| | - Lijie Sun
- J Craig Venter Institute, La Jolla, United States
| | | | | | | | - John D Lapek
- Department of Pharmacology and School of Pharmacy, University of California at San Diego, La Jolla, United States
| | - David J Gonzalez
- Department of Pharmacology and School of Pharmacy, University of California at San Diego, La Jolla, United States
| | - Valérie de Crécy-Lagard
- Department of Microbiology and Cell Science, University of Florida, Gainesville, United States
| | - Drago Haas
- Department of Microbiology and Cell Science, University of Florida, Gainesville, United States
| | - Andrew D Hanson
- Horticultural Sciences Department, University of Florida, Gainesville, United States
| | - Piyush Labhsetwar
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, United States
| | - John I Glass
- J Craig Venter Institute, La Jolla, United States
| | - Zaida Luthey-Schulten
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, United States
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22
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Abstract
Actinobacteria is a group of diverse bacteria. Most species in this class of bacteria are filamentous aerobes found in soil, including the genus Streptomyces perhaps best known for their fascinating capabilities of producing antibiotics. These bacteria typically have a Gram-positive cell envelope, comprised of a plasma membrane and a thick peptidoglycan layer. However, there is a notable exception of the Corynebacteriales order, which has evolved a unique type of outer membrane likely as a consequence of convergent evolution. In this chapter, we will focus on the unique cell envelope of this order. This cell envelope features the peptidoglycan layer that is covalently modified by an additional layer of arabinogalactan . Furthermore, the arabinogalactan layer provides the platform for the covalent attachment of mycolic acids , some of the longest natural fatty acids that can contain ~100 carbon atoms per molecule. Mycolic acids are thought to be the main component of the outer membrane, which is composed of many additional lipids including trehalose dimycolate, also known as the cord factor. Importantly, a subset of bacteria in the Corynebacteriales order are pathogens of human and domestic animals, including Mycobacterium tuberculosis. The surface coat of these pathogens are the first point of contact with the host immune system, and we now know a number of host receptors specific to molecular patterns exposed on the pathogen's surface, highlighting the importance of understanding how the cell envelope of Actinobacteria is structured and constructed. This chapter describes the main structural and biosynthetic features of major components found in the actinobacterial cell envelopes and highlights the key differences between them.
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Affiliation(s)
- Kathryn C Rahlwes
- Department of Microbiology, University of Massachusetts, 639 North Pleasant Street, Amherst, MA, 01003, USA
| | - Ian L Sparks
- Department of Microbiology, University of Massachusetts, 639 North Pleasant Street, Amherst, MA, 01003, USA
| | - Yasu S Morita
- Department of Microbiology, University of Massachusetts, 639 North Pleasant Street, Amherst, MA, 01003, USA.
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23
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Ati J, Colas C, Lafite P, Sweeney RP, Zheng RB, Lowary TL, Daniellou R. The LPG1x family from Leishmania major is constituted of rare eukaryotic galactofuranosyltransferases with unprecedented catalytic properties. Sci Rep 2018; 8:17566. [PMID: 30514885 PMCID: PMC6279836 DOI: 10.1038/s41598-018-35847-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 11/09/2018] [Indexed: 12/15/2022] Open
Abstract
Galactofuranosyltransferases are poorly described enzymes despite their crucial role in the virulence and the pathogenicity of numerous microorganisms. These enzymes are considered as potential targets for therapeutic action. In addition to the only well-characterised prokaryotic GlfT2 from Mycobacterium tuberculosis, four putative genes in Leishmania major were previously described as potential galactofuranosyltransferases. In this study, we have cloned, over-expressed, purified and fully determined the kinetic parameters of these four eukaryotic enzymes, thus demonstrating their unique potency in catalysing the transfer of the galactofuranosyl moiety into acceptors. Their individual promiscuity revealed to be different, as some of them could efficiently use NDP-pyranoses as donor substrates in addition to the natural UDP-galactofuranose. Such results pave the way for the development of chemoenzymatic synthesis of furanosyl-containing glycoconjugates as well as the design of improved drugs against leishmaniasis.
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Affiliation(s)
- Jihen Ati
- Institut de Chimie Organique et Analytique, UMR CNRS 7311, Université d'Orléans, Rue de Chartres, BP6759, Orléans, Cedex 02, France
| | - Cyril Colas
- Institut de Chimie Organique et Analytique, UMR CNRS 7311, Université d'Orléans, Rue de Chartres, BP6759, Orléans, Cedex 02, France
| | - Pierre Lafite
- Institut de Chimie Organique et Analytique, UMR CNRS 7311, Université d'Orléans, Rue de Chartres, BP6759, Orléans, Cedex 02, France
| | - Ryan P Sweeney
- Alberta Glycomics Centre and Department of Chemistry, The University of Alberta, Edmonton, AB, T6G 2G2, Canada
| | - Ruixiang Blake Zheng
- Alberta Glycomics Centre and Department of Chemistry, The University of Alberta, Edmonton, AB, T6G 2G2, Canada
| | - Todd L Lowary
- Alberta Glycomics Centre and Department of Chemistry, The University of Alberta, Edmonton, AB, T6G 2G2, Canada
| | - Richard Daniellou
- Institut de Chimie Organique et Analytique, UMR CNRS 7311, Université d'Orléans, Rue de Chartres, BP6759, Orléans, Cedex 02, France.
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24
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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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25
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Puffal J, García-Heredia A, Rahlwes KC, Siegrist MS, Morita YS. Spatial control of cell envelope biosynthesis in mycobacteria. Pathog Dis 2018; 76:4953754. [DOI: 10.1093/femspd/fty027] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 03/25/2018] [Indexed: 11/12/2022] Open
Affiliation(s)
- Julia Puffal
- Department of Microbiology, University of Massachusetts, Amherst, MA 01003, USA
| | - Alam García-Heredia
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA 01003, USA
| | - Kathryn C Rahlwes
- Department of Microbiology, University of Massachusetts, Amherst, MA 01003, USA
| | - M Sloan Siegrist
- Department of Microbiology, University of Massachusetts, Amherst, MA 01003, USA
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA 01003, USA
| | - Yasu S Morita
- Department of Microbiology, University of Massachusetts, Amherst, MA 01003, USA
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA 01003, USA
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26
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Xue X, Zheng RB, Koizumi A, Han L, Klassen JS, Lowary TL. Synthetic polyprenol-pyrophosphate linked oligosaccharides are efficient substrates for mycobacterial galactan biosynthetic enzymes. Org Biomol Chem 2018; 16:1939-1957. [DOI: 10.1039/c8ob00316e] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Synthetic glycosyl polyprenol phosphates are substrates for enzymes required for cell wall assembly in mycobacteria, including the organism that causes tuberculosis.
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Affiliation(s)
- Xiaochao Xue
- Alberta Glycomics Centre and Department of Chemistry
- University of Alberta
- Edmonton
- Canada
| | - Ruixiang Blake Zheng
- Alberta Glycomics Centre and Department of Chemistry
- University of Alberta
- Edmonton
- Canada
| | - Akihiko Koizumi
- Alberta Glycomics Centre and Department of Chemistry
- University of Alberta
- Edmonton
- Canada
| | - Ling Han
- Alberta Glycomics Centre and Department of Chemistry
- University of Alberta
- Edmonton
- Canada
| | - John S. Klassen
- Alberta Glycomics Centre and Department of Chemistry
- University of Alberta
- Edmonton
- Canada
| | - Todd L. Lowary
- Alberta Glycomics Centre and Department of Chemistry
- University of Alberta
- Edmonton
- Canada
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27
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Wesener DA, Levengood MR, Kiessling LL. Comparing Galactan Biosynthesis in Mycobacterium tuberculosis and Corynebacterium diphtheriae. J Biol Chem 2016; 292:2944-2955. [PMID: 28039359 DOI: 10.1074/jbc.m116.759340] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Revised: 12/28/2016] [Indexed: 11/06/2022] Open
Abstract
The suborder Corynebacterineae encompasses species like Corynebacterium glutamicum, which has been harnessed for industrial production of amino acids, as well as Corynebacterium diphtheriae and Mycobacterium tuberculosis, which cause devastating human diseases. A distinctive component of the Corynebacterineae cell envelope is the mycolyl-arabinogalactan (mAG) complex. The mAG is composed of lipid mycolic acids, and arabinofuranose (Araf) and galactofuranose (Galf) carbohydrate residues. Elucidating microbe-specific differences in mAG composition could advance biotechnological applications and lead to new antimicrobial targets. To this end, we compare and contrast galactan biosynthesis in C. diphtheriae and M. tuberculosis In each species, the galactan is constructed from uridine 5'-diphosphate-α-d-galactofuranose (UDP-Galf), which is generated by the enzyme UDP-galactopyranose mutase (UGM or Glf). UGM and the galactan are essential in M. tuberculosis, but their importance in Corynebacterium species was not known. We show that small molecule inhibitors of UGM impede C. glutamicum growth, suggesting that the galactan is critical in corynebacteria. Previous cell wall analysis data suggest the galactan polymer is longer in mycobacterial species than corynebacterial species. To explore the source of galactan length variation, a C. diphtheriae ortholog of the M. tuberculosis carbohydrate polymerase responsible for the bulk of galactan polymerization, GlfT2, was produced, and its catalytic activity was evaluated. The C. diphtheriae GlfT2 gave rise to shorter polysaccharides than those obtained with the M. tuberculosis GlfT2. These data suggest that GlfT2 alone can influence galactan length. Our results provide tools, both small molecule and genetic, for probing and perturbing the assembly of the Corynebacterineae cell envelope.
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Affiliation(s)
| | - Matthew R Levengood
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - Laura L Kiessling
- From the Department of Biochemistry and .,Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706
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28
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Recent advancements in the development of anti-tuberculosis drugs. Bioorg Med Chem Lett 2016; 27:370-386. [PMID: 28017531 DOI: 10.1016/j.bmcl.2016.11.084] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 11/16/2016] [Accepted: 11/27/2016] [Indexed: 01/09/2023]
Abstract
Modern chemotherapy has significantly improved patient outcomes against drug-sensitive tuberculosis. However, the rapid emergence of drug-resistant tuberculosis, together with the bacterium's ability to persist and remain latent present a major public health challenge. To overcome this problem, research into novel anti-tuberculosis targets and drug candidates is thus of paramount importance. This review article provides an overview of tuberculosis highlighting the recent advances and tools that are employed in the field of anti-tuberculosis drug discovery. The predominant focus is on anti-tuberculosis agents that are currently in the pipeline, i.e. clinical trials.
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29
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Albesa-Jové D, Guerin ME. The conformational plasticity of glycosyltransferases. Curr Opin Struct Biol 2016; 40:23-32. [DOI: 10.1016/j.sbi.2016.07.007] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 05/23/2016] [Accepted: 07/08/2016] [Indexed: 12/22/2022]
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30
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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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31
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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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32
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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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33
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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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34
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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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35
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Dugard CK, Mertz RA, Rayon C, Mercadante D, Hart C, Benatti MR, Olek AT, SanMiguel PJ, Cooper BR, Reiter WD, McCann MC, Carpita NC. The Cell Wall Arabinose-Deficient Arabidopsis thaliana Mutant murus5 Encodes a Defective Allele of REVERSIBLY GLYCOSYLATED POLYPEPTIDE2. PLANT PHYSIOLOGY 2016; 171:1905-20. [PMID: 27217494 PMCID: PMC4936543 DOI: 10.1104/pp.15.01922] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Accepted: 05/19/2016] [Indexed: 05/23/2023]
Abstract
Traditional marker-based mapping and next-generation sequencing was used to determine that the Arabidopsis (Arabidopsis thaliana) low cell wall arabinose mutant murus5 (mur5) encodes a defective allele of REVERSIBLY GLYCOSYLATED POLYPEPTIDE2 (RGP2). Marker analysis of 13 F2 confirmed mutant progeny from a recombinant mapping population gave a rough map position on the upper arm of chromosome 5, and deep sequencing of DNA from these 13 lines gave five candidate genes with G→A (C→T) transitions predicted to result in amino acid changes. Of these five, only insertional mutant alleles of RGP2, a gene that encodes a UDP-arabinose mutase that interconverts UDP-arabinopyranose and UDP-arabinofuranose, exhibited the low cell wall arabinose phenotype. The identities of mur5 and two SALK insertional alleles were confirmed by allelism tests and overexpression of wild-type RGP2 complementary DNA placed under the control of the 35S promoter in the three alleles. The mur5 mutation results in the conversion of cysteine-257 to tyrosine-257 within a conserved hydrophobic cluster predicted to be distal to the active site and essential for protein stability and possible heterodimerization with other isoforms of RGP.
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Affiliation(s)
- Christopher K Dugard
- Department of Botany and Plant Pathology (C.K.D., R.A.M., A.T.O., N.C.C.), Department of Biological Sciences (M.R.B., M.C.M., N.C.C.), Bindley Bioscience Center (B.R.C., M.C.M., N.C.C.), and Department of Horticulture and Landscape Architecture (P.J.S.), Purdue University, West Lafayette, Indiana 47907-2054;Université de Picardie Jules Verne, EA 3900-BIOPI, 80039 Amiens, France (C.R.);Heidelberg Institut für Theoretische Studien, Molecular Biomechanics, 69118 Heidelberg, Germany (D.M.); andDepartment of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269 (C.H., W.-D.R.)
| | - Rachel A Mertz
- Department of Botany and Plant Pathology (C.K.D., R.A.M., A.T.O., N.C.C.), Department of Biological Sciences (M.R.B., M.C.M., N.C.C.), Bindley Bioscience Center (B.R.C., M.C.M., N.C.C.), and Department of Horticulture and Landscape Architecture (P.J.S.), Purdue University, West Lafayette, Indiana 47907-2054;Université de Picardie Jules Verne, EA 3900-BIOPI, 80039 Amiens, France (C.R.);Heidelberg Institut für Theoretische Studien, Molecular Biomechanics, 69118 Heidelberg, Germany (D.M.); andDepartment of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269 (C.H., W.-D.R.)
| | - Catherine Rayon
- Department of Botany and Plant Pathology (C.K.D., R.A.M., A.T.O., N.C.C.), Department of Biological Sciences (M.R.B., M.C.M., N.C.C.), Bindley Bioscience Center (B.R.C., M.C.M., N.C.C.), and Department of Horticulture and Landscape Architecture (P.J.S.), Purdue University, West Lafayette, Indiana 47907-2054;Université de Picardie Jules Verne, EA 3900-BIOPI, 80039 Amiens, France (C.R.);Heidelberg Institut für Theoretische Studien, Molecular Biomechanics, 69118 Heidelberg, Germany (D.M.); andDepartment of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269 (C.H., W.-D.R.)
| | - Davide Mercadante
- Department of Botany and Plant Pathology (C.K.D., R.A.M., A.T.O., N.C.C.), Department of Biological Sciences (M.R.B., M.C.M., N.C.C.), Bindley Bioscience Center (B.R.C., M.C.M., N.C.C.), and Department of Horticulture and Landscape Architecture (P.J.S.), Purdue University, West Lafayette, Indiana 47907-2054;Université de Picardie Jules Verne, EA 3900-BIOPI, 80039 Amiens, France (C.R.);Heidelberg Institut für Theoretische Studien, Molecular Biomechanics, 69118 Heidelberg, Germany (D.M.); andDepartment of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269 (C.H., W.-D.R.)
| | - Christopher Hart
- Department of Botany and Plant Pathology (C.K.D., R.A.M., A.T.O., N.C.C.), Department of Biological Sciences (M.R.B., M.C.M., N.C.C.), Bindley Bioscience Center (B.R.C., M.C.M., N.C.C.), and Department of Horticulture and Landscape Architecture (P.J.S.), Purdue University, West Lafayette, Indiana 47907-2054;Université de Picardie Jules Verne, EA 3900-BIOPI, 80039 Amiens, France (C.R.);Heidelberg Institut für Theoretische Studien, Molecular Biomechanics, 69118 Heidelberg, Germany (D.M.); andDepartment of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269 (C.H., W.-D.R.)
| | - Matheus R Benatti
- Department of Botany and Plant Pathology (C.K.D., R.A.M., A.T.O., N.C.C.), Department of Biological Sciences (M.R.B., M.C.M., N.C.C.), Bindley Bioscience Center (B.R.C., M.C.M., N.C.C.), and Department of Horticulture and Landscape Architecture (P.J.S.), Purdue University, West Lafayette, Indiana 47907-2054;Université de Picardie Jules Verne, EA 3900-BIOPI, 80039 Amiens, France (C.R.);Heidelberg Institut für Theoretische Studien, Molecular Biomechanics, 69118 Heidelberg, Germany (D.M.); andDepartment of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269 (C.H., W.-D.R.)
| | - Anna T Olek
- Department of Botany and Plant Pathology (C.K.D., R.A.M., A.T.O., N.C.C.), Department of Biological Sciences (M.R.B., M.C.M., N.C.C.), Bindley Bioscience Center (B.R.C., M.C.M., N.C.C.), and Department of Horticulture and Landscape Architecture (P.J.S.), Purdue University, West Lafayette, Indiana 47907-2054;Université de Picardie Jules Verne, EA 3900-BIOPI, 80039 Amiens, France (C.R.);Heidelberg Institut für Theoretische Studien, Molecular Biomechanics, 69118 Heidelberg, Germany (D.M.); andDepartment of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269 (C.H., W.-D.R.)
| | - Phillip J SanMiguel
- Department of Botany and Plant Pathology (C.K.D., R.A.M., A.T.O., N.C.C.), Department of Biological Sciences (M.R.B., M.C.M., N.C.C.), Bindley Bioscience Center (B.R.C., M.C.M., N.C.C.), and Department of Horticulture and Landscape Architecture (P.J.S.), Purdue University, West Lafayette, Indiana 47907-2054;Université de Picardie Jules Verne, EA 3900-BIOPI, 80039 Amiens, France (C.R.);Heidelberg Institut für Theoretische Studien, Molecular Biomechanics, 69118 Heidelberg, Germany (D.M.); andDepartment of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269 (C.H., W.-D.R.)
| | - Bruce R Cooper
- Department of Botany and Plant Pathology (C.K.D., R.A.M., A.T.O., N.C.C.), Department of Biological Sciences (M.R.B., M.C.M., N.C.C.), Bindley Bioscience Center (B.R.C., M.C.M., N.C.C.), and Department of Horticulture and Landscape Architecture (P.J.S.), Purdue University, West Lafayette, Indiana 47907-2054;Université de Picardie Jules Verne, EA 3900-BIOPI, 80039 Amiens, France (C.R.);Heidelberg Institut für Theoretische Studien, Molecular Biomechanics, 69118 Heidelberg, Germany (D.M.); andDepartment of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269 (C.H., W.-D.R.)
| | - Wolf-Dieter Reiter
- Department of Botany and Plant Pathology (C.K.D., R.A.M., A.T.O., N.C.C.), Department of Biological Sciences (M.R.B., M.C.M., N.C.C.), Bindley Bioscience Center (B.R.C., M.C.M., N.C.C.), and Department of Horticulture and Landscape Architecture (P.J.S.), Purdue University, West Lafayette, Indiana 47907-2054;Université de Picardie Jules Verne, EA 3900-BIOPI, 80039 Amiens, France (C.R.);Heidelberg Institut für Theoretische Studien, Molecular Biomechanics, 69118 Heidelberg, Germany (D.M.); andDepartment of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269 (C.H., W.-D.R.)
| | - Maureen C McCann
- Department of Botany and Plant Pathology (C.K.D., R.A.M., A.T.O., N.C.C.), Department of Biological Sciences (M.R.B., M.C.M., N.C.C.), Bindley Bioscience Center (B.R.C., M.C.M., N.C.C.), and Department of Horticulture and Landscape Architecture (P.J.S.), Purdue University, West Lafayette, Indiana 47907-2054;Université de Picardie Jules Verne, EA 3900-BIOPI, 80039 Amiens, France (C.R.);Heidelberg Institut für Theoretische Studien, Molecular Biomechanics, 69118 Heidelberg, Germany (D.M.); andDepartment of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269 (C.H., W.-D.R.)
| | - Nicholas C Carpita
- Department of Botany and Plant Pathology (C.K.D., R.A.M., A.T.O., N.C.C.), Department of Biological Sciences (M.R.B., M.C.M., N.C.C.), Bindley Bioscience Center (B.R.C., M.C.M., N.C.C.), and Department of Horticulture and Landscape Architecture (P.J.S.), Purdue University, West Lafayette, Indiana 47907-2054;Université de Picardie Jules Verne, EA 3900-BIOPI, 80039 Amiens, France (C.R.);Heidelberg Institut für Theoretische Studien, Molecular Biomechanics, 69118 Heidelberg, Germany (D.M.); andDepartment of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269 (C.H., W.-D.R.)
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Spatially distinct and metabolically active membrane domain in mycobacteria. Proc Natl Acad Sci U S A 2016; 113:5400-5. [PMID: 27114527 DOI: 10.1073/pnas.1525165113] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Protected from host immune attack and antibiotic penetration by their unique cell envelope, mycobacterial pathogens cause devastating human diseases such as tuberculosis. Seamless coordination of cell growth with cell envelope elongation at the pole maintains this barrier. Unraveling this spatiotemporal regulation is a potential strategy for controlling mycobacterial infections. Our biochemical analysis previously revealed two functionally distinct membrane fractions in Mycobacterium smegmatis cell lysates: plasma membrane tightly associated with the cell wall (PM-CW) and a distinct fraction of pure membrane free of cell wall components (PMf). To provide further insight into the functions of these membrane fractions, we took the approach of comparative proteomics and identified more than 300 proteins specifically associated with the PMf, including essential enzymes involved in cell envelope synthesis such as a mannosyltransferase, Ppm1, and a galactosyltransferase, GlfT2. Furthermore, comparative lipidomics revealed the distinct lipid composition of the PMf, with specific association of key cell envelope biosynthetic precursors. Live-imaging fluorescence microscopy visualized the PMf as patches of membrane spatially distinct from the PM-CW and notably enriched in the pole of the growing cells. Taken together, our study provides the basis for assigning the PMf as a spatiotemporally distinct and metabolically active membrane domain involved in cell envelope biogenesis.
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Abstract
The cell wall of Mycobacterium tuberculosis is unique in that it differs significantly from those of both Gram-negative and Gram-positive bacteria. The thick, carbohydrate- and lipid-rich cell wall with distinct lipoglycans enables mycobacteria to survive under hostile conditions such as shortage of nutrients and antimicrobial exposure. The key features of this highly complex cell wall are the mycolyl-arabinogalactan-peptidoglycan (mAGP)-based and phosphatidyl-myo-inositol-based macromolecular structures, with the latter possessing potent immunomodulatory properties. These structures are crucial for the growth, viability, and virulence of M. tuberculosis and therefore are often the targets of effective chemotherapeutic agents against tuberculosis. Over the past decade, sophisticated genomic and molecular tools have advanced our understanding of the primary structure and biosynthesis of these macromolecules. The availability of the full genome sequences of various mycobacterial species, including M. tuberculosis, Mycobacterium marinum, and Mycobacterium bovis BCG, have greatly facilitated the identification of large numbers of drug targets and antigens specific to tuberculosis. Techniques to manipulate mycobacteria have also improved extensively; the conditional expression-specialized transduction essentiality test (CESTET) is currently used to determine the essentiality of individual genes. Finally, various biosynthetic assays using either purified proteins or synthetic cell wall acceptors have been developed to study enzyme function. This article focuses on the recent advances in determining the structural details and biosynthesis of arabinogalactan, lipoarabinomannan, and related glycoconjugates.
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Oka T, Goto M. Biosynthesis of Galactofuranose-containing Glycans in Filamentous Fungi. TRENDS GLYCOSCI GLYC 2016. [DOI: 10.4052/tigg.1428.1j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Takuji Oka
- Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo, University
| | - Masatoshi Goto
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University
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39
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Oka T, Goto M. Biosynthesis of Galactofuranose-containing Glycans in Filamentous Fungi. TRENDS GLYCOSCI GLYC 2016. [DOI: 10.4052/tigg.1428.1e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Takuji Oka
- Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo, University
| | - Masatoshi Goto
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University
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40
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Affiliation(s)
- Monika Jankute
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom;
| | - Jonathan A.G. Cox
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom;
| | - James Harrison
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom;
| | - Gurdyal S. Besra
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom;
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41
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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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42
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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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43
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Alderwick LJ, Harrison J, Lloyd GS, Birch HL. The Mycobacterial Cell Wall--Peptidoglycan and Arabinogalactan. Cold Spring Harb Perspect Med 2015; 5:a021113. [PMID: 25818664 DOI: 10.1101/cshperspect.a021113] [Citation(s) in RCA: 133] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The mycobacterial bacillus is encompassed by a remarkably elaborate cell wall structure. The mycolyl-arabinogalactan-peptidoglycan (mAGP) complex is essential for the viability of Mycobacterium tuberculosis and maintains a robust basal structure supporting the upper "myco-membrane." M. tuberculosis peptidoglycan, although appearing to be unexceptional at first glance, contains a number of unique molecular subtleties that become particularly important as the TB-bacilli enters into nonreplicative growth during dormancy. Arabinogalactan, a highly branched polysaccharide, serves to connect peptidoglycan with the outer mycolic acid layer, and a variety of unique glycolsyltransferases are used for its assembly. In this review, we shall explore the microbial chemistry of this unique heteropolysacchride, examine the molecular genetics that underpins its fabrication, and discuss how the essential biosynthetic process might be exploited for the development of future anti-TB chemotherapies.
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Affiliation(s)
- Luke J Alderwick
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - James Harrison
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Georgina S Lloyd
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Helen L Birch
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
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44
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Liang DM, Liu JH, Wu H, Wang BB, Zhu HJ, Qiao JJ. Glycosyltransferases: mechanisms and applications in natural product development. Chem Soc Rev 2015; 44:8350-74. [DOI: 10.1039/c5cs00600g] [Citation(s) in RCA: 136] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Glycosylation reactions mainly catalyzed by glycosyltransferases (Gts) occur almost everywhere in the biosphere, and always play crucial roles in vital processes.
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Affiliation(s)
- Dong-Mei Liang
- Department of Pharmaceutical Engineering
- School of Chemical Engineering and Technology
- Tianjin University
- Tianjin 300072
- China
| | - Jia-Heng Liu
- Department of Pharmaceutical Engineering
- School of Chemical Engineering and Technology
- Tianjin University
- Tianjin 300072
- China
| | - Hao Wu
- Department of Pharmaceutical Engineering
- School of Chemical Engineering and Technology
- Tianjin University
- Tianjin 300072
- China
| | - Bin-Bin Wang
- Department of Pharmaceutical Engineering
- School of Chemical Engineering and Technology
- Tianjin University
- Tianjin 300072
- China
| | - Hong-Ji Zhu
- Department of Pharmaceutical Engineering
- School of Chemical Engineering and Technology
- Tianjin University
- Tianjin 300072
- China
| | - Jian-Jun Qiao
- Department of Pharmaceutical Engineering
- School of Chemical Engineering and Technology
- Tianjin University
- Tianjin 300072
- China
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45
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Tilve MJ, Gallo-Rodriguez C. Conformationally restricted 3,5-O-(di-tert-butylsilylene)-d-galactofuranosyl thioglycoside donor for 1,2-cis α-d-galactofuranosylation. Carbohydr Res 2014; 397:7-17. [DOI: 10.1016/j.carres.2014.07.024] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 07/29/2014] [Accepted: 07/30/2014] [Indexed: 01/07/2023]
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46
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Gloster TM. Advances in understanding glycosyltransferases from a structural perspective. Curr Opin Struct Biol 2014; 28:131-41. [PMID: 25240227 PMCID: PMC4330554 DOI: 10.1016/j.sbi.2014.08.012] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2014] [Accepted: 08/20/2014] [Indexed: 01/23/2023]
Abstract
Glycosyltransferases are the enzymes that catalyse glycosidic bond formation. Structural and kinetic studies are important for understanding function. Bacterial oligosaccharyltransferase structure aids understanding of N-linked glycosylation. Structure of human O-GlcNAc transferase gives mechanistic insights. Landmark structure of cellulose synthase membrane protein complex.
Glycosyltransferases (GTs), the enzymes that catalyse glycosidic bond formation, create a diverse range of saccharides and glycoconjugates in nature. Understanding GTs at the molecular level, through structural and kinetic studies, is important for gaining insights into their function. In addition, this understanding can help identify those enzymes which are involved in diseases, or that could be engineered to synthesize biologically or medically relevant molecules. This review describes how structural data, obtained in the last 3–4 years, have contributed to our understanding of the mechanisms of action and specificity of GTs. Particular highlights include the structure of a bacterial oligosaccharyltransferase, which provides insights into N-linked glycosylation, the structure of the human O-GlcNAc transferase, and the structure of a bacterial integral membrane protein complex that catalyses the synthesis of cellulose, the most abundant organic molecule in the biosphere.
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Affiliation(s)
- Tracey M Gloster
- Biomedical Sciences Research Complex, North Haugh, University of St Andrews, St Andrews, Fife KY16 9ST, UK.
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47
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Angala SK, Belardinelli JM, Huc-Claustre E, Wheat WH, Jackson M. The cell envelope glycoconjugates of Mycobacterium tuberculosis. Crit Rev Biochem Mol Biol 2014; 49:361-99. [PMID: 24915502 PMCID: PMC4436706 DOI: 10.3109/10409238.2014.925420] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Tuberculosis (TB) remains the second most common cause of death due to a single infectious agent. The cell envelope of Mycobacterium tuberculosis (Mtb), the causative agent of the disease in humans, is a source of unique glycoconjugates and the most distinctive feature of the biology of this organism. It is the basis of much of Mtb pathogenesis and one of the major causes of its intrinsic resistance to chemotherapeutic agents. At the same time, the unique structures of Mtb cell envelope glycoconjugates, their antigenicity and essentiality for mycobacterial growth provide opportunities for drug, vaccine, diagnostic and biomarker development, as clearly illustrated by recent advances in all of these translational aspects. This review focuses on our current understanding of the structure and biogenesis of Mtb glycoconjugates with particular emphasis on one of the most intriguing and least understood aspect of the physiology of mycobacteria: the translocation of these complex macromolecules across the different layers of the cell envelope. It further reviews the rather impressive progress made in the last 10 years in the discovery and development of novel inhibitors targeting their biogenesis.
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Affiliation(s)
- Shiva Kumar Angala
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University , Fort Collins, CO , USA
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48
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Zhao G, Wu B, Li L, Wang PG. O-antigen polymerase adopts a distributive mechanism for lipopolysaccharide biosynthesis. Appl Microbiol Biotechnol 2014; 98:4075-81. [PMID: 24557568 DOI: 10.1007/s00253-014-5552-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2013] [Revised: 12/09/2013] [Accepted: 01/18/2014] [Indexed: 01/08/2023]
Abstract
Bacterial lipopolysaccharide (LPS) is an essential cell envelope component for gram-negative bacteria. As the most variable region of LPS, O antigens serve as important virulence determinants for many bacteria and represent a promising carbohydrate source for glycoconjugate vaccines. In the Wzy-dependent O-antigen biosynthetic pathway, the integral membrane protein Wzy was shown to be the sole enzyme responsible for polymerization of O-repeat unit. Its catalytic mechanism, however, remains elusive. Herein, Wzy was successfully overexpressed in Escherichia coli with an N-terminal His10-tag. Blue native polyacrylamide gel electrophoresis (BN-PAGE) revealed that the Wzy protein exists in its native confirmation as a dimer. Subsequently, we chemo-enzymatically synthesized the substrates of Wzy, the lipid-PP-linked repeat units. Together with an optimized O-antigen visualization method, we monitored the production of reaction intermediates at varying times. We present here our result as the first biochemical evidence that Wzy functions in a distributive manner.
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Affiliation(s)
- Guohui Zhao
- Center for Diagnostics and Therapeutics and Department of Chemistry, Georgia State University, Atlanta, GA, 30303, USA
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49
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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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50
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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: 12] [Impact Index Per Article: 1.1] [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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