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Goetsch AG, Ufearo D, Keiser G, Heiss C, Azadi P, Hershey DM. A novel exopolysaccharide pathway from a freshwater Sphingomonas isolate. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.03.565537. [PMID: 37961232 PMCID: PMC10635127 DOI: 10.1101/2023.11.03.565537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Bacteria embellish their cell envelopes with a variety of specialized polysaccharides. Biosynthesis pathways for these glycans are complex, and final products vary greatly in their chemical structures, physical properties and biological activities. This tremendous diversity comes from the ability to arrange complex pools of monosaccharide building blocks into polymers with many possible linkage configurations. Due to the complex chemistry of bacterial glycans, very few biosynthetic pathways have been defined in detail. To better understand the breadth of polysaccharide production in nature we isolated a bacterium from Lake Michigan called Sphingomonas sp. LM7 that is proficient in exopolysaccharide (EPS) production. We identified genes that contribute to EPS biosynthesis in LM7 by screening a transposon mutant library for colonies displaying altered colony morphology. A gene cluster was identified that appears to encode a complete wzy/wzx-dependent polysaccharide assembly pathway. Deleting individual genes in this cluster caused a non-mucoid phenotype and a corresponding loss of EPS secretion, confirming that LM7 assembles a novel wzy/wzx-dependent polysaccharide. We extracted EPS from LM7 cultures and showed that it contains a linear chain of 3- and 4- linked glucose, galactose, and glucuronic acid residues. Finally, we found that the EPS pathway we identified diverges from those of adhesive polysaccharides such as the holdfast that are conserved in higher Alphaproteobacteria. Our approach of characterizing complete biosynthetic pathways holds promise for engineering of polysaccharides with valuable properties.
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Affiliation(s)
- Alexandra G. Goetsch
- Department of Bacteriology, University of Wisconsin – Madison, Madison, WI 53706, USA
| | - Daniel Ufearo
- Department of Bacteriology, University of Wisconsin – Madison, Madison, WI 53706, USA
| | - Griffin Keiser
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | - Christian Heiss
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | - Parastoo Azadi
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | - David M. Hershey
- Department of Bacteriology, University of Wisconsin – Madison, Madison, WI 53706, USA
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2
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Greenwich JL, Fleming D, Banin E, Häussler S, Kjellerup BV, Sauer K, Visick KL, Fuqua C. The biofilm community resurfaces: new findings and post-pandemic progress. J Bacteriol 2023; 205:e0016623. [PMID: 37756166 PMCID: PMC10601713 DOI: 10.1128/jb.00166-23] [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] [Indexed: 09/29/2023] Open
Abstract
The ninth American Society for Microbiology Conference on Biofilms was convened in-person on 13-17 November 2022 in Charlotte, NC. As the first of these conferences since prior to the start of the COVID-19 pandemic, the energy among the participants of the conference was clear, and the meeting was a tremendous success. The mixture of >330 oral and poster presentations resoundingly embodied the vitality of biofilm research across a wide range of topics and multiple scientific disciplines. Special activities, including a pre-conference symposium for early career researchers, further enhanced the attendee experience. As a general theme, the conference was deliberately structured to provide high levels of participation and engagement among early career scientists.
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Affiliation(s)
| | - Derek Fleming
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - Ehud Banin
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | | | - Birthe V. Kjellerup
- Department of Civil and Environmental Engineering, University of Maryland, College Park, Maryland, USA
| | - Karin Sauer
- Department of Biological Sciences, University of Binghamton, Binghamton, New York, USA
| | - Karen L. Visick
- Department of Microbiology and Immunology, Loyola University Chicago, Maywood, Illinois, USA
| | - Clay Fuqua
- Department of Biology, Indiana University, Bloomington, Indiana, USA
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3
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Stefanović C, Hager-Mair FF, Breslmayr E, López-Guzmán A, Lim C, Blaukopf M, Kosma P, Oostenbrink C, Ludwig R, Schäffer C. Molecular modelling and site-directed mutagenesis provide insight into saccharide pyruvylation by the Paenibacillus alvei CsaB enzyme. Sci Rep 2023; 13:13394. [PMID: 37591902 PMCID: PMC10435577 DOI: 10.1038/s41598-023-40072-1] [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: 02/26/2023] [Accepted: 08/03/2023] [Indexed: 08/19/2023] Open
Abstract
Pyruvylation is a biologically versatile but mechanistically unexplored saccharide modification. 4,6-Ketal pyruvylated N-acetylmannosamine within bacterial secondary cell wall polymers serves as a cell wall anchoring epitope for proteins possessing a terminal S-layer homology domain trimer. The pyruvyltransferase CsaB from Paenibacillus alvei served as a model to investigate the structural basis of the pyruvyltransfer reaction by a combination of molecular modelling and site-directed mutagenesis together with an enzyme assay using phosphoenolpyruvate (PEP; donor) and synthetic β-D-ManNAc-(1 → 4)-α-D-GlcNAc-diphosphoryl-11-phenoxyundecyl (acceptor). CsaB protein structure modelling was done using Phyre2 and I-Tasser based on the partial crystal structure of the Schizosaccharomyces pombe pyruvyltransferase Pvg1p and by AlphaFold. The models informed the construction of twelve CsaB mutants targeted at plausible PEP and acceptor binding sites and KM and kcat values were determined to evaluate the mutants, indicating the importance of a loop region for catalysis. R148, H308 and K328 were found to be critical to PEP binding and insight into acceptor binding was obtained from an analysis of Y14 and F16 mutants, confirming the modelled binding sites and interactions predicted using Molecular Operating Environment. These data lay the basis for future mechanistic studies of saccharide pyruvylation as a novel target for interference with bacterial cell wall assembly.
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Affiliation(s)
- Cordula Stefanović
- NanoGlycobiology Research Group, Department of Chemistry, Institute of Biochemistry, Universität für Bodenkultur Wien, Muthgasse 18, 1190, Vienna, Austria
- Department of Bionanosciences, Institute of Biologically Inspired Materials, Universität für Bodenkultur Wien, Muthgasse 11, 1190, Vienna, Austria
| | - Fiona F Hager-Mair
- NanoGlycobiology Research Group, Department of Chemistry, Institute of Biochemistry, Universität für Bodenkultur Wien, Muthgasse 18, 1190, Vienna, Austria
- Department of Bionanosciences, Institute of Biologically Inspired Materials, Universität für Bodenkultur Wien, Muthgasse 11, 1190, Vienna, Austria
| | - Erik Breslmayr
- Department of Food Science and Technology, Biocatalysis and Biosensing Laboratory, Universität für Bodenkultur Wien, Muthgasse 11, 1190, Vienna, Austria
- Department of Material Sciences and Process Engineering, Institute for Molecular Modelling and Simulation, Universität für Bodenkultur Wien, Muthgasse 18, 1190, Vienna, Austria
| | - Arturo López-Guzmán
- NanoGlycobiology Research Group, Department of Chemistry, Institute of Biochemistry, Universität für Bodenkultur Wien, Muthgasse 18, 1190, Vienna, Austria
- Department of Bionanosciences, Institute of Biologically Inspired Materials, Universität für Bodenkultur Wien, Muthgasse 11, 1190, Vienna, Austria
- Covirabio GmbH, Brehmstrasse 14a, 1110, Vienna, Austria
| | - Charlie Lim
- Department of Chemistry, Institute of Organic Chemistry, Universität für Bodenkultur Wien, Muthgasse 18, 1190, Vienna, Austria
| | - Markus Blaukopf
- Department of Chemistry, Institute of Organic Chemistry, Universität für Bodenkultur Wien, Muthgasse 18, 1190, Vienna, Austria
| | - Paul Kosma
- Department of Chemistry, Institute of Organic Chemistry, Universität für Bodenkultur Wien, Muthgasse 18, 1190, Vienna, Austria
| | - Chris Oostenbrink
- Department of Material Sciences and Process Engineering, Institute for Molecular Modelling and Simulation, Universität für Bodenkultur Wien, Muthgasse 18, 1190, Vienna, Austria
| | - Roland Ludwig
- Department of Food Science and Technology, Biocatalysis and Biosensing Laboratory, Universität für Bodenkultur Wien, Muthgasse 11, 1190, Vienna, Austria
| | - Christina Schäffer
- NanoGlycobiology Research Group, Department of Chemistry, Institute of Biochemistry, Universität für Bodenkultur Wien, Muthgasse 18, 1190, Vienna, Austria.
- Department of Bionanosciences, Institute of Biologically Inspired Materials, Universität für Bodenkultur Wien, Muthgasse 11, 1190, Vienna, Austria.
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4
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Kelly SD, Ovchinnikova OG, Müller F, Steffen M, Braun M, Sweeney RP, Kowarik M, Follador R, Lowary TL, Serventi F, Whitfield C. Identification of a second glycoform of the clinically prevalent O1 antigen from Klebsiella pneumoniae. Proc Natl Acad Sci U S A 2023; 120:e2301302120. [PMID: 37428935 PMCID: PMC10629545 DOI: 10.1073/pnas.2301302120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 05/15/2023] [Indexed: 07/12/2023] Open
Abstract
Carbapenemase and extended β-lactamase-producing Klebsiella pneumoniae isolates represent a major health threat, stimulating increasing interest in immunotherapeutic approaches for combating Klebsiella infections. Lipopolysaccharide O antigen polysaccharides offer viable targets for immunotherapeutic development, and several studies have described protection with O-specific antibodies in animal models of infection. O1 antigen is produced by almost half of clinical Klebsiella isolates. The O1 polysaccharide backbone structure is known, but monoclonal antibodies raised against the O1 antigen showed varying reactivity against different isolates that could not be explained by the known structure. Reinvestigation of the structure by NMR spectroscopy revealed the presence of the reported polysaccharide backbone (glycoform O1a), as well as a previously unknown O1b glycoform composed of the O1a backbone modified with a terminal pyruvate group. The activity of the responsible pyruvyltransferase (WbbZ) was confirmed by western immunoblotting and in vitro chemoenzymatic synthesis of the O1b terminus. Bioinformatic data indicate that almost all O1 isolates possess genes required to produce both glycoforms. We describe the presence of O1ab-biosynthesis genes in other bacterial species and report a functional O1 locus on a bacteriophage genome. Homologs of wbbZ are widespread in genetic loci for the assembly of unrelated glycostructures in bacteria and yeast. In K. pneumoniae, simultaneous production of both O1 glycoforms is enabled by the lack of specificity of the ABC transporter that exports the nascent glycan, and the data reported here provide mechanistic understanding of the capacity for evolution of antigenic diversity within an important class of biomolecules produced by many bacteria.
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Affiliation(s)
- Steven D. Kelly
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ONN1G 2W1, Canada
| | - Olga G. Ovchinnikova
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ONN1G 2W1, Canada
| | | | | | - Martin Braun
- LimmaTech Biologics AG, Schlieren8952, Switzerland
| | - Ryan P. Sweeney
- Department of Chemistry, University of Alberta, Edmonton, ABT6G 2G2, Canada
| | | | | | - Todd L. Lowary
- Department of Chemistry, University of Alberta, Edmonton, ABT6G 2G2, Canada
- Institute of Biological Chemistry, Academia Sinica, Taipei, Nangang11529, Taiwan
- Institute of Biochemical Sciences, National Taiwan University, Taipei10617, Taiwan
| | | | - Chris Whitfield
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ONN1G 2W1, Canada
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5
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Lee CG, Cha KH, Kim GC, Im SH, Kwon HK. Exploring probiotic effector molecules and their mode of action in gut-immune interactions. FEMS Microbiol Rev 2023; 47:fuad046. [PMID: 37541953 DOI: 10.1093/femsre/fuad046] [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: 02/13/2023] [Revised: 07/17/2023] [Accepted: 08/03/2023] [Indexed: 08/06/2023] Open
Abstract
Probiotics, live microorganisms that confer health benefits when consumed in adequate amounts, have gained significant attention for their potential therapeutic applications. The beneficial effects of probiotics are believed to stem from their ability to enhance intestinal barrier function, inhibit pathogens, increase beneficial gut microbes, and modulate immune responses. However, clinical studies investigating the effectiveness of probiotics have yielded conflicting results, potentially due to the wide variety of probiotic species and strains used, the challenges in controlling the desired number of live microorganisms, and the complex interactions between bioactive substances within probiotics. Bacterial cell wall components, known as effector molecules, play a crucial role in mediating the interaction between probiotics and host receptors, leading to the activation of signaling pathways that contribute to the health-promoting effects. Previous reviews have extensively covered different probiotic effector molecules, highlighting their impact on immune homeostasis. Understanding how each probiotic component modulates immune activity at the molecular level may enable the prediction of immunological outcomes in future clinical studies. In this review, we present a comprehensive overview of the structural and immunological features of probiotic effector molecules, focusing primarily on Lactobacillus and Bifidobacterium. We also discuss current gaps and limitations in the field and propose directions for future research to enhance our understanding of probiotic-mediated immunomodulation.
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Affiliation(s)
- Choong-Gu Lee
- Natural Product Informatics Research Center, Korea Institute of Science and Technology, 679, Saimdang-ro, Gangneung 25451, Korea
- Division of Bio-Medical Science and Technology, KIST School, University of Science and Technology, 679, Saimdang-ro, Seoul 02792, Korea
- Department of Convergence Medicine, Wonju College of Medicine, Yonsei University, 20, Ilsan-ro, Wonju 26493, Korea
| | - Kwang Hyun Cha
- Natural Product Informatics Research Center, Korea Institute of Science and Technology, 679, Saimdang-ro, Gangneung 25451, Korea
- Division of Bio-Medical Science and Technology, KIST School, University of Science and Technology, 679, Saimdang-ro, Seoul 02792, Korea
- Department of Convergence Medicine, Wonju College of Medicine, Yonsei University, 20, Ilsan-ro, Wonju 26493, Korea
| | - Gi-Cheon Kim
- Department of Microbiology and Immunology, Institute for Immunology and Immunological Diseases, and Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seoul 03722, Korea
| | - Sin-Hyeog Im
- Department of Life Sciences, Pohang University of Science and Technology, 77, Cheongam-ro, Pohang 37673, Korea
- Institute for Convergence Research and Education, Yonsei University, 50-1 Yonsei-ro, Seoul 03722, Korea
- ImmunoBiome Inc, Bio Open Innovation Center, 77, Cheongam-ro, Pohang 37673 , Korea
| | - Ho-Keun Kwon
- Department of Microbiology and Immunology, Institute for Immunology and Immunological Diseases, and Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seoul 03722, Korea
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6
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Reid A, Erickson KM, Hazel JM, Lukose V, Troutman JM. Chemoenzymatic Preparation of a Campylobacter jejuni Lipid-Linked Heptasaccharide on an Azide-Linked Polyisoprenoid. ACS OMEGA 2023; 8:15790-15798. [PMID: 37151508 PMCID: PMC10157688 DOI: 10.1021/acsomega.3c01657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Accepted: 04/13/2023] [Indexed: 05/09/2023]
Abstract
Complex poly- and oligosaccharides on the surface of bacteria provide a unique fingerprint to different strains of pathogenic and symbiotic microbes that could be exploited for therapeutics or sensors selective for specific glycans. To discover reagents that can selectively interact with specific bacterial glycans, a system for both the chemoenzymatic preparation and immobilization of these materials would be ideal. Bacterial glycans are typically synthesized in nature on the C55 polyisoprenoid bactoprenyl (or undecaprenyl) phosphate. However, this long-chain isoprenoid can be difficult to work with in vitro. Here, we describe the addition of a chemically functional benzylazide tag to polyisoprenoids. We have found that both the organic-soluble and water-soluble benzylazide isoprenoid can serve as a substrate for the well-characterized system responsible for Campylobacter jejuni N-linked heptasaccharide assembly. Using the organic-soluble analogue, we demonstrate the use of an N-acetyl-glucosamine epimerase that can be used to lower the cost of glycan assembly, and using the water-soluble analogue, we demonstrate the immobilization of the C. jejuni heptasaccharide on magnetic beads. These conjugated beads are then shown to interact with soybean agglutinin, a lectin known to interact with N-acetyl-galactosamine in the C. jejuni heptasaccharide. The methods provided could be used for a wide variety of applications including the discovery of new glycan-interacting partners.
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Affiliation(s)
- Amanda
J. Reid
- Nanoscale
Science Program, University of North Carolina
at Charlotte, 9201 University City Blvd., Charlotte, North Carolina 28223, United States
| | - Katelyn M. Erickson
- Nanoscale
Science Program, University of North Carolina
at Charlotte, 9201 University City Blvd., Charlotte, North Carolina 28223, United States
| | - Joseph M. Hazel
- Department
of Chemistry, University of North Carolina
at Charlotte, 9201 University
City Blvd., Charlotte, North
Carolina 28223, United States
- Department
of Chemistry, The Ohio State University, 281 W Lane Avenue, Columbus, Ohio 43210, United States
| | - Vinita Lukose
- Departments
of Chemistry and Biology, Massachusetts
Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Jerry M. Troutman
- Nanoscale
Science Program, University of North Carolina
at Charlotte, 9201 University City Blvd., Charlotte, North Carolina 28223, United States
- Department
of Chemistry, University of North Carolina
at Charlotte, 9201 University
City Blvd., Charlotte, North
Carolina 28223, United States
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7
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Banahene N, Kavunja HW, Swarts BM. Chemical Reporters for Bacterial Glycans: Development and Applications. Chem Rev 2022; 122:3336-3413. [PMID: 34905344 PMCID: PMC8958928 DOI: 10.1021/acs.chemrev.1c00729] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Bacteria possess an extraordinary repertoire of cell envelope glycans that have critical physiological functions. Pathogenic bacteria have glycans that are essential for growth and virulence but are absent from humans, making them high-priority targets for antibiotic, vaccine, and diagnostic development. The advent of metabolic labeling with bioorthogonal chemical reporters and small-molecule fluorescent reporters has enabled the investigation and targeting of specific bacterial glycans in their native environments. These tools have opened the door to imaging glycan dynamics, assaying and inhibiting glycan biosynthesis, profiling glycoproteins and glycan-binding proteins, and targeting pathogens with diagnostic and therapeutic payload. These capabilities have been wielded in diverse commensal and pathogenic Gram-positive, Gram-negative, and mycobacterial species─including within live host organisms. Here, we review the development and applications of chemical reporters for bacterial glycans, including peptidoglycan, lipopolysaccharide, glycoproteins, teichoic acids, and capsular polysaccharides, as well as mycobacterial glycans, including trehalose glycolipids and arabinan-containing glycoconjugates. We cover in detail how bacteria-targeting chemical reporters are designed, synthesized, and evaluated, how they operate from a mechanistic standpoint, and how this information informs their judicious and innovative application. We also provide a perspective on the current state and future directions of the field, underscoring the need for interdisciplinary teams to create novel tools and extend existing tools to support fundamental and translational research on bacterial glycans.
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8
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Hager-Mair FF, Stefanović C, Lim C, Webhofer K, Krauter S, Blaukopf M, Ludwig R, Kosma P, Schäffer C. Assaying Paenibacillus alvei CsaB-Catalysed Ketalpyruvyltransfer to Saccharides by Measurement of Phosphate Release. Biomolecules 2021; 11:biom11111732. [PMID: 34827730 PMCID: PMC8615578 DOI: 10.3390/biom11111732] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/12/2021] [Accepted: 11/17/2021] [Indexed: 12/15/2022] Open
Abstract
Ketalpyruvyltransferases belong to a widespread but little investigated class of enzymes, which utilise phosphoenolpyruvate (PEP) for the pyruvylation of saccharides. Pyruvylated saccharides play pivotal biological roles, ranging from protein binding to virulence. Limiting factors for the characterisation of ketalpyruvyltransferases are the availability of cognate acceptor substrates and a straightforward enzyme assay. We report on a fast ketalpyruvyltransferase assay based on the colorimetric detection of phosphate released during pyruvyltransfer from PEP onto the acceptor via complexation with Malachite Green and molybdate. To optimise the assay for the model 4,6-ketalpyruvyl::ManNAc-transferase CsaB from Paenibacillus alvei, a β-d-ManNAc-α-d-GlcNAc-diphosphoryl-11-phenoxyundecyl acceptor mimicking an intermediate of the bacterium's cell wall glycopolymer biosynthesis pathway, upon which CsaB is naturally active, was produced chemo-enzymatically and used together with recombinant CsaB. Optimal assay conditions were 5 min reaction time at 37 °C and pH 7.5, followed by colour development for 1 h at 37 °C and measurement of absorbance at 620 nm. The structure of the generated pyruvylated product was confirmed by NMR spectroscopy. Using the established assay, the first kinetic constants of a 4,6-ketalpyuvyl::ManNAc-transferase could be determined; upon variation of the acceptor and PEP concentrations, a KM, PEP of 19.50 ± 3.50 µM and kcat, PEP of 0.21 ± 0.01 s-1 as well as a KM, Acceptor of 258 ± 38 µM and a kcat, Acceptor of 0.15 ± 0.01 s-1 were revealed. P. alvei CsaB was inactive on synthetic pNP-β-d-ManNAc and β-d-ManNAc-β-d-GlcNAc-1-OMe, supporting the necessity of a complex acceptor substrate.
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Affiliation(s)
- Fiona F. Hager-Mair
- NanoGlycobiology Unit, Department of NanoBiotechnology, Universität für Bodenkultur Wien, 1190 Vienna, Austria; (F.F.H.-M.); (C.S.)
| | - Cordula Stefanović
- NanoGlycobiology Unit, Department of NanoBiotechnology, Universität für Bodenkultur Wien, 1190 Vienna, Austria; (F.F.H.-M.); (C.S.)
| | - Charlie Lim
- Department of Chemistry, Institute of Organic Chemistry, Universität für Bodenkultur Wien, 1190 Vienna, Austria; (C.L.); (K.W.); (S.K.); (M.B.); (P.K.)
| | - Katharina Webhofer
- Department of Chemistry, Institute of Organic Chemistry, Universität für Bodenkultur Wien, 1190 Vienna, Austria; (C.L.); (K.W.); (S.K.); (M.B.); (P.K.)
| | - Simon Krauter
- Department of Chemistry, Institute of Organic Chemistry, Universität für Bodenkultur Wien, 1190 Vienna, Austria; (C.L.); (K.W.); (S.K.); (M.B.); (P.K.)
| | - Markus Blaukopf
- Department of Chemistry, Institute of Organic Chemistry, Universität für Bodenkultur Wien, 1190 Vienna, Austria; (C.L.); (K.W.); (S.K.); (M.B.); (P.K.)
| | - Roland Ludwig
- Biocatalysis and Biosensing Laboratory, Department of Food Science and Technology, Universität für Bodenkultur Wien, 1190 Vienna, Austria;
| | - Paul Kosma
- Department of Chemistry, Institute of Organic Chemistry, Universität für Bodenkultur Wien, 1190 Vienna, Austria; (C.L.); (K.W.); (S.K.); (M.B.); (P.K.)
| | - Christina Schäffer
- NanoGlycobiology Unit, Department of NanoBiotechnology, Universität für Bodenkultur Wien, 1190 Vienna, Austria; (F.F.H.-M.); (C.S.)
- Correspondence: ; Tel.: +43-1-47654 (ext. 80203)
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9
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Identification of a Novel Pyruvyltransferase Using 13C Solid-State Nuclear Magnetic Resonance To Analyze Rhizobial Exopolysaccharides. J Bacteriol 2021; 203:e0040321. [PMID: 34606371 DOI: 10.1128/jb.00403-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The alphaproteobacterium Sinorhizobium meliloti secretes two acidic exopolysaccharides (EPSs), succinoglycan (EPSI) and galactoglucan (EPSII), which differentially enable it to adapt to a changing environment. Succinoglycan is essential for invasion of plant hosts and, thus, for the formation of nitrogen-fixing root nodules. Galactoglucan is critical for population-based behaviors such as swarming and biofilm formation and can facilitate invasion in the absence of succinoglycan on some host plants. The biosynthesis of galactoglucan is not as completely understood as that of succinoglycan. We devised a pipeline to identify putative pyruvyltransferase and acetyltransferase genes, construct genomic deletions in strains engineered to produce either succinoglycan or galactoglucan, and analyze EPS from mutant bacterial strains. EPS samples were examined by 13C cross-polarization magic-angle spinning (CPMAS) solid-state nuclear magnetic resonance (NMR). CPMAS NMR is uniquely suited to defining chemical composition in complex samples and enables the detection and quantification of distinct EPS functional groups. Galactoglucan was isolated from mutant strains with deletions in five candidate acyl/acetyltransferase genes (exoZ, exoH, SMb20810, SMb21188, and SMa1016) and a putative pyruvyltransferase (wgaE or SMb21322). Most samples were similar in composition to wild-type EPSII by CPMAS NMR analysis. However, galactoglucan produced from a strain lacking wgaE exhibited a significant reduction in pyruvylation. Pyruvylation was restored through the ectopic expression of plasmid-borne wgaE. Our work has thus identified WgaE as a galactoglucan pyruvyltransferase. This exemplifies how the systematic combination of genetic analyses and solid-state NMR detection is a rapid means to identify genes responsible for modification of rhizobial exopolysaccharides. IMPORTANCE Nitrogen-fixing bacteria are crucial for geochemical cycles and global nitrogen nutrition. Symbioses between legumes and rhizobial bacteria establish root nodules, where bacteria convert dinitrogen to ammonia for plant utilization. Secreted exopolysaccharides (EPSs) produced by Sinorhizobium meliloti (succinoglycan and galactoglucan) play important roles in soil and plant environments. The biosynthesis of galactoglucan is not as well characterized as that of succinoglycan. We employed solid-state nuclear magnetic resonance (NMR) to examine intact EPS from wild-type and mutant S. meliloti strains. NMR analysis of EPS isolated from a wgaE gene mutant revealed a novel pyruvyltransferase that modifies galactoglucan. Few EPS pyruvyltransferases have been characterized. Our work provides insight into the biosynthesis of an important S. meliloti EPS and expands the knowledge of enzymes that modify polysaccharides.
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10
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Zheng M, Zheng M, Epstein S, Harnagel AP, Kim H, Lupoli TJ. Chemical Biology Tools for Modulating and Visualizing Gram-Negative Bacterial Surface Polysaccharides. ACS Chem Biol 2021; 16:1841-1865. [PMID: 34569792 DOI: 10.1021/acschembio.1c00341] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Bacterial cells present a wide diversity of saccharides that decorate the cell surface and help mediate interactions with the environment. Many Gram-negative cells express O-antigens, which are long sugar polymers that makeup the distal portion of lipopolysaccharide (LPS) that constitutes the surface of the outer membrane. This review highlights chemical biology tools that have been developed in recent years to facilitate the modulation of O-antigen synthesis and composition, as well as related bacterial polysaccharide pathways, and the detection of unique glycan sequences. Advances in the biochemistry and structural biology of O-antigen biosynthetic machinery are also described, which provide guidance for the design of novel chemical and biomolecular probes. Many of the tools noted here have not yet been utilized in biological systems and offer researchers the opportunity to investigate the complex sugar architecture of Gram-negative cells.
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Affiliation(s)
- Meng Zheng
- Department of Chemistry, New York University, New York, 10003 New York, United States
| | - Maggie Zheng
- Department of Chemistry, New York University, New York, 10003 New York, United States
| | - Samuel Epstein
- Department of Chemistry, New York University, New York, 10003 New York, United States
| | - Alexa P. Harnagel
- Department of Chemistry, New York University, New York, 10003 New York, United States
| | - Hanee Kim
- Department of Chemistry, New York University, New York, 10003 New York, United States
| | - Tania J. Lupoli
- Department of Chemistry, New York University, New York, 10003 New York, United States
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11
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Scarbrough BA, Eade CR, Reid AJ, Williams TC, Troutman JM. Lipopolysaccharide Is a 4-Aminoarabinose Donor to Exogenous Polyisoprenyl Phosphates through the Reverse Reaction of the Enzyme ArnT. ACS OMEGA 2021; 6:25729-25741. [PMID: 34632229 PMCID: PMC8495848 DOI: 10.1021/acsomega.1c04036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Indexed: 05/11/2023]
Abstract
Modification of the lipid A portion of LPS with cationic monosaccharides provides resistance to polymyxins, which are often employed as a last resort to treat multidrug-resistant bacterial infections. Here, we describe the use of fluorescent polyisoprenoids, liquid chromatography-mass spectrometry, and bacterial genetics to probe the activity of membrane-localized proteins that utilize the 55-carbon lipid carrier bactoprenyl phosphate (BP). We have discovered that a substantial background reaction occurs when B-strain E. coli cell membrane fractions are supplemented with exogenous BP. This reaction involves proteins associated with the arn operon, which is necessary for the covalent modification of lipid A with the cationic 4-aminoarabinose (Ara4N). Using a series of arn operon gene deletion mutants, we identified that the modification was dependent on ArnC, which is responsible for forming BP-linked Ara4N, or ArnT, which transfers Ara4N to lipid A. Surprisingly, we found that the majority of the Ara4N-modified isoprenoid was due to the reverse reaction catalyzed by ArnT and demonstrate this using heat-inactivated membrane fractions, isolated lipopolysaccharide fractions, and analyses of a purified ArnT. This work provides methods that will facilitate thorough and rapid investigation of bacterial outer membrane remodeling and the evaluation of polyisoprenoid precursors required for covalent glycan modifications.
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Affiliation(s)
- Beth A. Scarbrough
- Nanoscale
Science Program, The University of North
Carolina at Charlotte, Charlotte, North Carolina 28223-0001, United States
| | - Colleen R. Eade
- Department
of Chemistry, The University of North Carolina
at Charlotte, Charlotte, North Carolina 28223-0001, United States
| | - Amanda J. Reid
- Nanoscale
Science Program, The University of North
Carolina at Charlotte, Charlotte, North Carolina 28223-0001, United States
| | - Tiffany C. Williams
- Department
of Chemistry, The University of North Carolina
at Charlotte, Charlotte, North Carolina 28223-0001, United States
| | - Jerry M. Troutman
- Department
of Chemistry, The University of North Carolina
at Charlotte, Charlotte, North Carolina 28223-0001, United States
- Nanoscale
Science Program, The University of North
Carolina at Charlotte, Charlotte, North Carolina 28223-0001, United States
- . Phone: 704-687-5180
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12
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Luong P, Dube DH. Dismantling the bacterial glycocalyx: Chemical tools to probe, perturb, and image bacterial glycans. Bioorg Med Chem 2021; 42:116268. [PMID: 34130219 DOI: 10.1016/j.bmc.2021.116268] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 05/27/2021] [Accepted: 06/01/2021] [Indexed: 12/20/2022]
Abstract
The bacterial glycocalyx is a quintessential drug target comprised of structurally distinct glycans. Bacterial glycans bear unusual monosaccharide building blocks whose proper construction is critical for bacterial fitness, survival, and colonization in the human host. Despite their appeal as therapeutic targets, bacterial glycans are difficult to study due to the presence of rare bacterial monosaccharides that are linked and modified in atypical manners. Their structural complexity ultimately hampers their analytical characterization. This review highlights recent advances in bacterial chemical glycobiology and focuses on the development of chemical tools to probe, perturb, and image bacterial glycans and their biosynthesis. Current technologies have enabled the study of bacterial glycosylation machinery even in the absence of detailed structural information.
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Affiliation(s)
- Phuong Luong
- Department of Chemistry & Biochemistry, Bowdoin College, 6600 College Station, Brunswick, ME 04011, USA
| | - Danielle H Dube
- Department of Chemistry & Biochemistry, Bowdoin College, 6600 College Station, Brunswick, ME 04011, USA.
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13
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Wu Q, Yu X, Li J, Sun S, Tu Y. Metabolic regulation in the immune response to cancer. Cancer Commun (Lond) 2021; 41:661-694. [PMID: 34145990 PMCID: PMC8360644 DOI: 10.1002/cac2.12182] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 03/25/2021] [Accepted: 06/11/2021] [Indexed: 02/06/2023] Open
Abstract
Metabolic reprogramming in tumor‐immune interactions is emerging as a key factor affecting pro‐inflammatory carcinogenic effects and anticancer immune responses. Therefore, dysregulated metabolites and their regulators affect both cancer progression and therapeutic response. Here, we describe the molecular mechanisms through which microenvironmental, systemic, and microbial metabolites potentially influence the host immune response to mediate malignant progression and therapeutic intervention. We summarized the primary interplaying factors that constitute metabolism, immunological reactions, and cancer with a focus on mechanistic aspects. Finally, we discussed the possibility of metabolic interventions at multiple levels to enhance the efficacy of immunotherapeutic and conventional approaches for future anticancer treatments.
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Affiliation(s)
- Qi Wu
- Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei, 430060, P. R. China
| | - Xin Yu
- Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei, 430060, P. R. China
| | - Juanjuan Li
- Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei, 430060, P. R. China
| | - Shengrong Sun
- Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei, 430060, P. R. China
| | - Yi Tu
- Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei, 430060, P. R. China
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14
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Wang H, Sun C, Sun X, Zhang L, Zhao J, Liang M, Xiao M, Gu G. Biochemical Characterization and Synthetic Application of α‐1,3‐Glucosyltransferase from Pneumococcus Serotype 18C. ChemCatChem 2021. [DOI: 10.1002/cctc.202100507] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Hong Wang
- National Glycoengineering Research Center and Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology Shandong University 72 Binhai Road 266237 Qingdao P. R. China
| | - Chongzhen Sun
- National Glycoengineering Research Center and Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology Shandong University 72 Binhai Road 266237 Qingdao P. R. China
| | - Xuan Sun
- National Glycoengineering Research Center and Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology Shandong University 72 Binhai Road 266237 Qingdao P. R. China
| | - Le Zhang
- National Glycoengineering Research Center and Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology Shandong University 72 Binhai Road 266237 Qingdao P. R. China
| | - Jielin Zhao
- National Glycoengineering Research Center and Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology Shandong University 72 Binhai Road 266237 Qingdao P. R. China
| | - Min Liang
- National Glycoengineering Research Center and Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology Shandong University 72 Binhai Road 266237 Qingdao P. R. China
| | - Min Xiao
- National Glycoengineering Research Center and Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology Shandong University 72 Binhai Road 266237 Qingdao P. R. China
| | - Guofeng Gu
- National Glycoengineering Research Center and Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology Shandong University 72 Binhai Road 266237 Qingdao P. R. China
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15
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Erturk-Hasdemir D, Ochoa-Repáraz J, Kasper DL, Kasper LH. Exploring the Gut-Brain Axis for the Control of CNS Inflammatory Demyelination: Immunomodulation by Bacteroides fragilis' Polysaccharide A. Front Immunol 2021; 12:662807. [PMID: 34025663 PMCID: PMC8131524 DOI: 10.3389/fimmu.2021.662807] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 04/16/2021] [Indexed: 12/12/2022] Open
Abstract
The symbiotic relationship between animals and their resident microorganisms has profound effects on host immunity. The human microbiota comprises bacteria that reside in the gastrointestinal tract and are involved in a range of inflammatory and autoimmune diseases. The gut microbiota's immunomodulatory effects extend to extraintestinal tissues, including the central nervous system (CNS). Specific symbiotic antigens responsible for inducing immunoregulation have been isolated from different bacterial species. Polysaccharide A (PSA) of Bacteroides fragilis is an archetypical molecule for host-microbiota interactions. Studies have shown that PSA has beneficial effects in experimental disease models, including experimental autoimmune encephalomyelitis (EAE), the most widely used animal model for multiple sclerosis (MS). Furthermore, in vitro stimulation with PSA promotes an immunomodulatory phenotype in human T cells isolated from healthy and MS donors. In this review, we discuss the current understanding of the interactions between gut microbiota and the host in the context of CNS inflammatory demyelination, the immunomodulatory roles of gut symbionts. More specifically, we also discuss the immunomodulatory effects of B. fragilis PSA in the gut-brain axis and its therapeutic potential in MS. Elucidation of the molecular mechanisms responsible for the microbiota's impact on host physiology offers tremendous promise for discovering new therapies.
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Affiliation(s)
| | | | - Dennis L. Kasper
- Department of Immunology, Harvard Medical School, Boston, MA, United States
| | - Lloyd H. Kasper
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth College, Hanover, NH, United States
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16
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Eade CR, Wallen TW, Gates CE, Oliverio CL, Scarbrough BA, Reid AJ, Jorgenson MA, Young KD, Troutman JM. Making the Enterobacterial Common Antigen Glycan and Measuring Its Substrate Sequestration. ACS Chem Biol 2021; 16:691-700. [PMID: 33740380 DOI: 10.1021/acschembio.0c00983] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The enterobacterial common antigen (ECA), a three-sugar repeat unit polysaccharide produced by Enterobacteriaceae family members, impacts bacterial outer membrane permeability, and its biosynthesis affects the glycan landscape of the organism. ECA synthesis impacts the production of other polysaccharides by reducing the availability of shared substrates, the most notable of which is the 55-carbon polyisoprenoid bactoprenyl phosphate (BP), which serves as a carrier for the production of numerous bacterial glycans including ECA, peptidoglycan, O-antigen, and more. Here, using a combination of in vitro enzymatic synthesis and liquid chromatography-mass spectrometry (LC-MS) analysis of bacterial lysates, we provide biochemical evidence for the effect on endogenous polyisoprenoid pools from cell culture that arises from glycan pathway disruption. In this work, we have cloned and expressed each gene involved in ECA repeat unit biosynthesis and reconstituted the pathway in vitro, providing LC-MS characterized standards for the investigation of cellular glycan-linked intermediates and BP. We then generated ECA deficient mutants in genes associated with production of the polysaccharide, which we suspected would accumulate materials identical to our standards. We found that indeed accumulated products from these cells were indistinguishable from our enzymatically prepared standards, and moreover we observed a concomitant decrease in cellular BP levels with each mutant. This work provides the first direct biochemical evidence for the sequestration of BP upon the genetic disruption of glycan biosynthesis pathways in bacteria. This work also provides methods for the direct assessment of both the ECA glycan, and a new understanding of the dynamic interdependence of the bacterial polysaccharide repertoire.
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Affiliation(s)
- Colleen R. Eade
- Department of Chemistry, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
| | - Timothy W. Wallen
- Department of Chemistry, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
| | - Claire E. Gates
- Department of Chemistry, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
- Biological and Biomedical Sciences Program, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Cassidy L. Oliverio
- Department of Chemistry, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
| | - Beth A. Scarbrough
- Department of Chemistry, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
| | - Amanda J. Reid
- Department of Chemistry, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
| | - Matthew A. Jorgenson
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, United States
| | - Kevin D. Young
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, United States
| | - Jerry M. Troutman
- Department of Chemistry, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
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17
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Williams DA, Pradhan K, Paul A, Olin IR, Tuck OT, Moulton KD, Kulkarni SS, Dube DH. Metabolic inhibitors of bacterial glycan biosynthesis. Chem Sci 2020; 11:1761-1774. [PMID: 34123271 PMCID: PMC8148367 DOI: 10.1039/c9sc05955e] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 01/08/2020] [Indexed: 12/14/2022] Open
Abstract
The bacterial cell wall is a quintessential drug target due to its critical role in colonization of the host, pathogen survival, and immune evasion. The dense cell wall glycocalyx contains distinctive monosaccharides that are absent from human cells, and proper assembly of monosaccharides into higher-order glycans is critical for bacterial fitness and pathogenesis. However, the systematic study and inhibition of bacterial glycosylation enzymes remains challenging. Bacteria produce glycans containing rare deoxy amino sugars refractory to traditional glycan analysis, complicating the study of bacterial glycans and the creation of glycosylation inhibitors. To ease the study of bacterial glycan function in the absence of detailed structural or enzyme information, we crafted metabolic inhibitors based on rare bacterial monosaccharide scaffolds. Metabolic inhibitors were assessed for their ability to interfere with glycan biosynthesis and fitness in pathogenic and symbiotic bacterial species. Three metabolic inhibitors led to dramatic structural and functional defects in Helicobacter pylori. Strikingly, these inhibitors acted in a bacteria-selective manner. These metabolic inhibitors will provide a platform for systematic study of bacterial glycosylation enzymes not currently possible with existing tools. Moreover, their selectivity will provide a pathway for the development of novel, narrow-spectrum antibiotics to treat infectious disease. Our inhibition approach is general and will expedite the identification of bacterial glycan biosynthesis inhibitors in a range of systems, expanding the glycochemistry toolkit.
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Affiliation(s)
- Daniel A Williams
- Department of Chemistry & Biochemistry, Bowdoin College 6600 College Station Brunswick ME 04011 USA
| | - Kabita Pradhan
- Department of Chemistry, Indian Institute of Technology Bombay Powai Mumbai 400076 India
| | - Ankita Paul
- Department of Chemistry, Indian Institute of Technology Bombay Powai Mumbai 400076 India
| | - Ilana R Olin
- Department of Chemistry & Biochemistry, Bowdoin College 6600 College Station Brunswick ME 04011 USA
| | - Owen T Tuck
- Department of Chemistry & Biochemistry, Bowdoin College 6600 College Station Brunswick ME 04011 USA
| | - Karen D Moulton
- Department of Chemistry & Biochemistry, Bowdoin College 6600 College Station Brunswick ME 04011 USA
| | - Suvarn S Kulkarni
- Department of Chemistry, Indian Institute of Technology Bombay Powai Mumbai 400076 India
| | - Danielle H Dube
- Department of Chemistry & Biochemistry, Bowdoin College 6600 College Station Brunswick ME 04011 USA
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18
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Reid AJ, Scarbrough BA, Williams TC, Gates CE, Eade CR, Troutman JM. General Utilization of Fluorescent Polyisoprenoids with Sugar Selective Phosphoglycosyltransferases. Biochemistry 2020; 59:615-626. [PMID: 31876413 DOI: 10.1021/acs.biochem.9b01026] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The protective surfaces of bacteria are comprised of polysaccharides and are involved in host invasion and colonization, host immune system evasion, and antibacterial resistance. A major barrier to our fundamental understanding of these complex surface polysaccharides lies in the tremendous diversity in glycan composition among bacterial species. The polyisoprenoid bactoprenyl phosphate (or undecaprenyl phosphate) is an essential lipid carrier necessary for early stages of glycopolymer assembly. Because of the ubiquity of bactoprenyl phosphate in these critical processes, molecular probes appended to this lipid carrier simplify identification of enzymatic roles during polysaccharide bioassembly. A limited number of these probes exist in the literature or have been assessed with such pathways, and the limits of their use are not currently known. Herein, we devise an efficient method for producing fluorescently modified bactoprenyl probes. We further expand our previous efforts utilizing 2-nitrileaniline and additionally prepare nitrobenzoxadizol-tagged bactoprenyl phosphate for the first time. We then assess the enzyme promiscuity of these two probes utilizing four well-characterized initiating phosphoglycosyltransferases: CPS2E (Streptococcus pneumoniae), WbaP (Salmonella enterica), WecA (Escherichia coli), and WecP (Aeromonas hydrophilia). Both probes serve as substrates for these enzymes and could be readily used to investigate a wide range of bacterial glycoassembly pathways. Interestingly, we have also identified unique solubility requirements for the nitrobenzoxadizol moiety for efficient enzymatic utilization that was not observed for the 2-nitrileaniline.
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19
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Cochrane RVK, Alexander FM, Boland C, Fetics SK, Caffrey M, Cochrane SA. From plant to probe: semi-synthesis of labelled undecaprenol analogues allows rapid access to probes for antibiotic targets. Chem Commun (Camb) 2020; 56:8603-8606. [DOI: 10.1039/d0cc03388j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Extraction of undecaprenol from bay leaves followed by synthetic modification is a convenient method to obtain novel chemical probes.
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Affiliation(s)
| | | | - Coilín Boland
- School of Medicine and School of Biochemistry and Immunology
- Trinity Biomedical Sciences Institute
- Trinity College Dublin
- Dublin 2
- Ireland
| | - Susan K. Fetics
- School of Medicine and School of Biochemistry and Immunology
- Trinity Biomedical Sciences Institute
- Trinity College Dublin
- Dublin 2
- Ireland
| | - Martin Caffrey
- School of Medicine and School of Biochemistry and Immunology
- Trinity Biomedical Sciences Institute
- Trinity College Dublin
- Dublin 2
- Ireland
| | - Stephen A. Cochrane
- School of Chemistry and Chemical Engineering
- Queen's University Belfast
- Belfast
- UK
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20
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Hager FF, Sützl L, Stefanović C, Blaukopf M, Schäffer C. Pyruvate Substitutions on Glycoconjugates. Int J Mol Sci 2019; 20:E4929. [PMID: 31590345 PMCID: PMC6801904 DOI: 10.3390/ijms20194929] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 09/25/2019] [Accepted: 09/27/2019] [Indexed: 12/15/2022] Open
Abstract
Glycoconjugates are the most diverse biomolecules of life. Mostly located at the cell surface, they translate into cell-specific "barcodes" and offer a vast repertoire of functions, including support of cellular physiology, lifestyle, and pathogenicity. Functions can be fine-tuned by non-carbohydrate modifications on the constituting monosaccharides. Among these modifications is pyruvylation, which is present either in enol or ketal form. The most commonly best-understood example of pyruvylation is enol-pyruvylation of N-acetylglucosamine, which occurs at an early stage in the biosynthesis of the bacterial cell wall component peptidoglycan. Ketal-pyruvylation, in contrast, is present in diverse classes of glycoconjugates, from bacteria to algae to yeast-but not in humans. Mild purification strategies preventing the loss of the acid-labile ketal-pyruvyl group have led to a collection of elucidated pyruvylated glycan structures. However, knowledge of involved pyruvyltransferases creating a ring structure on various monosaccharides is scarce, mainly due to the lack of knowledge of fingerprint motifs of these enzymes and the unavailability of genome sequences of the organisms undergoing pyruvylation. This review compiles the current information on the widespread but under-investigated ketal-pyruvylation of monosaccharides, starting with different classes of pyruvylated glycoconjugates and associated functions, leading to pyruvyltransferases, their specificity and sequence space, and insight into pyruvate analytics.
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Affiliation(s)
- Fiona F Hager
- Department of NanoBiotechnology, NanoGlycobiology unit, Universität für Bodenkultur Wien, Muthgasse 11, A-1190 Vienna, Austria.
| | - Leander Sützl
- Department of Food Science and Technology, Food Biotechnology Laboratory, Muthgasse 11, Universität für Bodenkultur Wien, A-1190 Vienna, Austria.
| | - Cordula Stefanović
- Department of NanoBiotechnology, NanoGlycobiology unit, Universität für Bodenkultur Wien, Muthgasse 11, A-1190 Vienna, Austria.
| | - Markus Blaukopf
- Department of Chemistry, Division of Organic Chemistry, Universität für Bodenkultur Wien, Muthgasse 18, A-1190 Vienna, Austria.
| | - Christina Schäffer
- Department of NanoBiotechnology, NanoGlycobiology unit, Universität für Bodenkultur Wien, Muthgasse 11, A-1190 Vienna, Austria.
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21
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Rosenberg E, Zilber‐Rosenberg I. The hologenome concept of evolution: do mothers matter most? BJOG 2019; 127:129-137. [DOI: 10.1111/1471-0528.15882] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/10/2019] [Indexed: 12/21/2022]
Affiliation(s)
- E Rosenberg
- Department of Molecular Microbiology and Biotechnology Tel Aviv University Ramat Aviv Israel
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22
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An extendable all-in-one injection twin derivatization LC-MS/MS strategy for the absolute quantification of multiple chemical-group-based submetabolomes. Anal Chim Acta 2019; 1063:99-109. [DOI: 10.1016/j.aca.2019.02.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 01/20/2019] [Accepted: 02/03/2019] [Indexed: 01/10/2023]
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23
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Nutritional Modulation of Immune and Central Nervous System Homeostasis: The Role of Diet in Development of Neuroinflammation and Neurological Disease. Nutrients 2019; 11:nu11051076. [PMID: 31096592 PMCID: PMC6566411 DOI: 10.3390/nu11051076] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Revised: 05/02/2019] [Accepted: 05/13/2019] [Indexed: 02/06/2023] Open
Abstract
The gut-microbiome-brain axis is now recognized as an essential part in the regulation of systemic metabolism and homeostasis. Accumulating evidence has demonstrated that dietary patterns can influence the development of metabolic alterations and inflammation through the effects of nutrients on a multitude of variables, including microbiome composition, release of microbial products, gastrointestinal signaling molecules, and neurotransmitters. These signaling molecules are, in turn, implicated in the regulation of the immune system, either promoting or inhibiting the production of pro-inflammatory cytokines and the expansion of specific leukocyte subpopulations, such as Th17 and Treg cells, which are relevant in the development of neuroinflammatory and neurodegenerative conditions. Metabolic diseases, like obesity and type 2 diabetes mellitus, are related to inadequate dietary patterns and promote variations in the aforementioned signaling pathways in patients with these conditions, which have been linked to alterations in neurological functions and mental health. Thus, maintenance of adequate dietary patterns should be an essential component of any strategy aiming to prevent neurological pathologies derived from systemic metabolic alterations. The present review summarizes current knowledge on the role of nutrition in the modulation of the immune system and its impact in the development of neuroinflammation and neurological disease.
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24
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Scott PM, Erickson KM, Troutman JM. Identification of the Functional Roles of Six Key Proteins in the Biosynthesis of Enterobacteriaceae Colanic Acid. Biochemistry 2019; 58:1818-1830. [PMID: 30821147 DOI: 10.1021/acs.biochem.9b00040] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
When subjected to harsh conditions such as low pH, pathogenic Escherichia coli can secrete colanic acid to establish a protective barrier between the organism and the acidic environment. The colanic acid consists of a six-sugar repeating unit polymer comprised of glucose, fucose, galactose, and glucuronic acid. The region of the E. coli genome that encodes colanic acid biosynthesis has been reported, and the first enzyme in the biosynthesis pathway has been biochemically characterized. However, the specific roles of the remaining genes required for colanic acid biosynthesis have not been identified. Here we report the in vitro reconstitution of the next six steps in the assembly of the colanic acid repeating unit. To do this, we have cloned and overexpressed each gene within the colanic acid biosynthesis operon. We then tested the activity of the protein product of these genes using high-performance liquid chromatography analysis and a fluorescent analogue of the isoprenoid anchor bactoprenyl diphospho-glucose as a starting substrate. To ensure that retention time changes were associated with varying sugar additions or modifications, we developed a liquid chromatography-mass spectrometry method for analysis of the products produced by each enzyme. We have identified the function of all but one encoded glycosyltransferase and have identified the function of two acetyltransferases. This work demonstrates the centrality of acetylation in the biosynthesis of colanic acid and provides insight into the activity of key proteins involved in the production of an important and highly conserved bacterial glycopolymer.
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25
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Abstract
All natural animals and plants are holobionts, consisting of the host and microbiome, which is composed of abundant and diverse microorganisms. Health and disease of holobionts depend as much on interactions between host and microbiome and within the microbiome, as on interactions between organs and body parts of the host. Recent evidence indicates that a significant fraction of the microbiome is transferred by a variety of mechanisms from parent to offspring for many generations. Genetic variation in holobionts can occur in the microbiome as well as in the host genome, and it occurs more rapidly and by more mechanisms in genomes of microbiomes than in host genomes (e.g. via acquisition of novel microbes and horizontal gene transfer of microbial genes into host chromosomes). Evidence discussed in this review supports the concept that holobionts with their hologenomes can be considered levels of selection in evolution. Though changes in the microbiome can lead to evolution of the holobiont, it can also lead to dysbiosis and diseases (e.g. obesity, diarrhea, inflammatory bowel disease, and autism). In practice, the possibility of manipulating microbiomes offers the potential to prevent and cure diseases.
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26
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Eradi P, Ghosh S, Andreana PR. Total Synthesis of Zwitterionic Tetrasaccharide Repeating Unit from Bacteroides fragilis ATCC 25285/NCTC 9343 Capsular Polysaccharide PS A1 with Alternating Charges on Adjacent Monosaccharides. Org Lett 2018; 20:4526-4530. [PMID: 30015493 DOI: 10.1021/acs.orglett.8b01829] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The tetrasaccharide repeating unit of zwitterionic polysaccharide A1 (PS A1) from Bacteroides fragilis ATCC 25285/NCTC 9343 has been synthesized using a linear glycosylation approach. One key step includes an α(1,4)-stereoselective [2 + 1] glycosylation of a 2,4,6-trideoxy-2-acetamido-4-amino-d-Gal p (AAT) donor with a poorly reactive axial C4-OH disaccharide acceptor. Mild acid-mediated deacetylation and a challenging [3 + 1] glycosylation are also highlighted. The strategy is inclusive of a single-pot, three-step deprotection affording PS A1 with alternating charges on adjacent monosaccharide units.
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Affiliation(s)
- Pradheep Eradi
- Department of Chemistry and Biochemistry and School of Green Chemistry and Engineering , University of Toledo , 2801 West Bancroft Street , Toledo , Ohio 43606 , United States
| | - Samir Ghosh
- Department of Chemistry and Biochemistry and School of Green Chemistry and Engineering , University of Toledo , 2801 West Bancroft Street , Toledo , Ohio 43606 , United States
| | - Peter R Andreana
- Department of Chemistry and Biochemistry and School of Green Chemistry and Engineering , University of Toledo , 2801 West Bancroft Street , Toledo , Ohio 43606 , United States
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Hager FF, López-Guzmán A, Krauter S, Blaukopf M, Polter M, Brockhausen I, Kosma P, Schäffer C. Functional Characterization of Enzymatic Steps Involved in Pyruvylation of Bacterial Secondary Cell Wall Polymer Fragments. Front Microbiol 2018; 9:1356. [PMID: 29997588 PMCID: PMC6030368 DOI: 10.3389/fmicb.2018.01356] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 06/05/2018] [Indexed: 12/15/2022] Open
Abstract
Various mechanisms of protein cell surface display have evolved during bacterial evolution. Several Gram-positive bacteria employ S-layer homology (SLH) domain-mediated sorting of cell-surface proteins and concomitantly engage a pyruvylated secondary cell-wall polymer as a cell-wall ligand. Specifically, pyruvate ketal linked to β-D-ManNAc is regarded as an indispensable epitope in this cell-surface display mechanism. That secondary cell wall polymer (SCWP) pyruvylation and SLH domain-containing proteins are functionally coupled is supported by the presence of an ortholog of the predicted pyruvyltransferase CsaB in bacterial genomes, such as those of Bacillus anthracis and Paenibacillus alvei. The P. alvei SCWP, consisting of pyruvylated disaccharide repeats [→4)-β-D-GlcNAc-(1→3)-4,6-Pyr-β-D-ManNAc-(1→] serves as a model to investigate the widely unexplored pyruvylation reaction. Here, we reconstituted the underlying enzymatic pathway in vitro in combination with synthesized compounds, used mass spectrometry, and nuclear magnetic resonance spectroscopy for product characterization, and found that CsaB-catalyzed pyruvylation of β-D-ManNAc occurs at the stage of the lipid-linked repeat. We produced the P. alvei TagA (PAV_RS07420) and CsaB (PAV_RS07425) enzymes as recombinant, tagged proteins, and using a synthetic 11-phenoxyundecyl-diphosphoryl-α-GlcNAc acceptor, we uncovered that TagA is an inverting UDP-α-D-ManNAc:GlcNAc-lipid carrier transferase, and that CsaB is a pyruvyltransferase, with synthetic UDP-α-D-ManNAc and phosphoenolpyruvate serving as donor substrates. Next, to substitute for the UDP-α-D-ManNAc substrate, the recombinant UDP-GlcNAc-2-epimerase MnaA (PAV_RS07610) of P. alvei was included in this in vitro reconstitution system. When all three enzymes, their substrates and the lipid-linked GlcNAc primer were combined in a one-pot reaction, a lipid-linked SCWP repeat precursor analog was obtained. This work highlights the biochemical basis of SCWP biosynthesis and bacterial pyruvyl transfer.
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Affiliation(s)
- Fiona F Hager
- NanoGlycobiology Unit, Department of NanoBiotechnology, Universität für Bodenkultur Wien, Vienna, Austria
| | - Arturo López-Guzmán
- NanoGlycobiology Unit, Department of NanoBiotechnology, Universität für Bodenkultur Wien, Vienna, Austria
| | - Simon Krauter
- Division of Organic Chemistry, Department of Chemistry, Universität für Bodenkultur Wien, Vienna, Austria
| | - Markus Blaukopf
- Division of Organic Chemistry, Department of Chemistry, Universität für Bodenkultur Wien, Vienna, Austria
| | - Mathias Polter
- NanoGlycobiology Unit, Department of NanoBiotechnology, Universität für Bodenkultur Wien, Vienna, Austria
| | - Inka Brockhausen
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada
| | - Paul Kosma
- Division of Organic Chemistry, Department of Chemistry, Universität für Bodenkultur Wien, Vienna, Austria
| | - Christina Schäffer
- NanoGlycobiology Unit, Department of NanoBiotechnology, Universität für Bodenkultur Wien, Vienna, Austria
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Rosenberg E, Zilber-Rosenberg I. The hologenome concept of evolution after 10 years. MICROBIOME 2018; 6:78. [PMID: 29695294 PMCID: PMC5922317 DOI: 10.1186/s40168-018-0457-9] [Citation(s) in RCA: 214] [Impact Index Per Article: 35.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 04/05/2018] [Indexed: 05/11/2023]
Abstract
The holobiont (host with its endocellular and extracellular microbiome) can function as a distinct biological entity, an additional organismal level to the ones previously considered, on which natural selection operates. The holobiont can function as a whole: anatomically, metabolically, immunologically, developmentally, and during evolution. Consideration of the holobiont with its hologenome as an independent level of selection in evolution has led to a better understanding of underappreciated modes of genetic variation and evolution. The hologenome is comprised of two complimentary parts: host and microbiome genomes. Changes in either genome can result in variations that can be selected for or against. The host genome is highly conserved, and genetic changes within it occur slowly, whereas the microbiome genome is dynamic and can change rapidly in response to the environment by increasing or reducing particular microbes, by acquisition of novel microbes, by horizontal gene transfer, and by mutation. Recent experiments showing that microbiota can play an initial role in speciation have been suggested as an additional mode of enhancing evolution. Some of the genetic variations can be transferred to offspring by a variety of mechanisms. Strain-specific DNA analysis has shown that at least some of the microbiota can be maintained across hundreds of thousands of host generations, implying the existence of a microbial core. We argue that rapid changes in the microbiome genome could allow holobionts to adapt and survive under changing environmental conditions thus providing the time necessary for the host genome to adapt and evolve. As Darwin wrote, "It is not the strongest of the species that survives but the most adaptable".
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Affiliation(s)
- Eugene Rosenberg
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
| | - Ilana Zilber-Rosenberg
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
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Erturk-Hasdemir D, Kasper DL. Finding a needle in a haystack: Bacteroides fragilis polysaccharide A as the archetypical symbiosis factor. Ann N Y Acad Sci 2018. [PMID: 29528123 DOI: 10.1111/nyas.13660] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Starting from birth, all animals develop a symbiotic relationship with their resident microorganisms that benefits both the microbe and the host. Recent advances in technology have substantially improved our ability to direct research toward the identification of important microbial species that affect host physiology. The identification of specific commensal molecules from these microbes and their mechanisms of action is still in its early stages. Polysaccharide A (PSA) of Bacteroides fragilis is the archetypical example of a commensal molecule that can modulate the host immune system in health and disease. This zwitterionic polysaccharide has a critical impact on the development of the mammalian immune system and also on the stimulation of interleukin 10-producing CD4+ T cells; consequently, PSA confers benefits to the host with regard to experimental autoimmune, inflammatory, and infectious diseases. In this review, we summarize the current understanding of the immunomodulatory effects of B. fragilis PSA and discuss these effects as a novel immunological paradigm. In particular, we discuss recent advances in our understanding of the unique functional mechanisms of this molecule and its therapeutic potential, and we review the recent literature in the field of microbiome research aimed at discovering new commensal products and their immunomodulatory potential.
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Affiliation(s)
- Deniz Erturk-Hasdemir
- Division of Immunology, Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts
| | - Dennis L Kasper
- Division of Immunology, Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts
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Zhang Q, Overkleeft HS, van der Marel GA, Codée JDC. Synthetic zwitterionic polysaccharides. Curr Opin Chem Biol 2017; 40:95-101. [DOI: 10.1016/j.cbpa.2017.07.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 06/27/2017] [Accepted: 07/20/2017] [Indexed: 10/18/2022]
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Abstract
The human gastrointestinal tract is populated by a diverse, highly mutualistic microbial flora, which is known as the microbiome. Disruptions to the microbiome have been shown to be associated with severe pathologies of the host, including metabolic disease, cancer, and inflammatory bowel disease. Mood and behavior are also susceptible to alterations in the gut microbiota. A particularly striking example of the symbiotic effects of the microbiome is the immune system, whose cells depend critically on a diverse array of microbial metabolites for normal development and behavior. This includes metabolites that are produced by bacteria from dietary components, metabolites that are produced by the host and biochemically modified by gut bacteria, and metabolites that are synthesized de novo by gut microbes. In this review, we highlight the role of the intestinal microbiome in human metabolic and inflammatory diseases and focus in particular on the molecular mechanisms that govern the gut-immune axis.
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Affiliation(s)
- Thomas Siegmund Postler
- Department of Microbiology and Immunology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Sankar Ghosh
- Department of Microbiology and Immunology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
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