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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; 11:1732. [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.)
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Sharipova RR, Garifullin BF, Sapunova AS, Voloshina AD, Kravchenko MA, Kataev VE. Synthesis and Biological Activity of 3,4,-Tri-О-Acetyl-N-Acetylglucosamine and Tetraacetylglucopyranose Conjugated with Alkyl Phosphates. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2019. [DOI: 10.1134/s1068162019020110] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Synthesis of Phenoxyundecyl Diphosphate Disaccharides for Studies of the Biosynthesis of O Antigenic Polysaccharides in Enteric Bacteria. Methods Mol Biol 2019; 1954:161-174. [PMID: 30864131 DOI: 10.1007/978-1-4939-9154-9_13] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
The biosynthesis of O antigenic polysaccharides in enteric bacteria from nucleoside diphosphate sugars (donor substrates) is catalyzed by the corresponding glycosyltransferases and proceeds through the intermediate formation of undecaprenyl diphosphate sugars (acceptor substrates). To study this process, a chemical synthesis of the compounds having the natural structure or their modified analogs is necessary. The phosphoroimidazolidate method is a universal method for synthesis of lipid diphosphate disaccharides containing 2-acetamido-2-deoxyglycosyl residue at the reducing end of the disaccharide moiety and 11-phenoxyundecyl residue as lipid fragment of the molecule. We report here protocols to synthesize the disaccharides P1-(11-phenoxyundecyl)-P2-(2-acetamido-2-deoxy-3-O-α-D-rhamnopyranosyl-α-D-glucopyranosyl) diphosphate [D-Rha(α1-3)-D-GlcNAcα-PP-PhU, Compound 1] and P1-(11-phenoxyundecyl)-P2-(2-acetamido-2-deoxy-3-O-β-D-galactopyranosyl-α-D-galactopyranosyl) diphosphate [D-Gal(β1-3)-D-GalNAcα-PP-PhU, Compound 6]. We describe the procedures for identification and structure estimation of compounds by TLC, NMR, and MS. We also include the biochemical testing of Compound 6 with α2,3-sialyltransferase WbwA from Escherichia coli O104.
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Doyle L, Ovchinnikova OG, Whitfield C. Utilization of Fluorescently Tagged Synthetic Acceptor Molecules for In Vitro Characterization of a Dual-Domain Glycosyltransferase Enzyme, KpsC, from Escherichia coli. Methods Mol Biol 2019; 1954:151-159. [PMID: 30864130 DOI: 10.1007/978-1-4939-9154-9_12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The incorporation of fluorescent tags into synthetic acceptor molecules for in vitro biochemical assays allows quick and easy detection of enzyme activity. Reaction products can be separated via thin-layer chromatography and visualized under UV light for rapid detection of reaction progress. Subsequent structural analysis of these reaction products through the use of NMR spectroscopy and mass spectrometry allows for complete functional characterization of enzyme activity. Here we describe an application of this technique which was previously used to functionally characterize a dual-domain glycosyltransferase enzyme, KpsC, involved in capsular polysaccharide biosynthesis in Escherichia coli.
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Affiliation(s)
- Liam Doyle
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada
| | - Olga G Ovchinnikova
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada
| | - Chris Whitfield
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada.
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Garifullin BF, Sharipova RR, Voloshina AD, Kravchenko MA, Kataev VE. Synthesis and Antitubercular and Antibacterial Activities of Triethylammonium 2-Acetamido-3,4,6-tri-O-acetyl-2-deoxy-D-glucopyranosyl Decyl Phosphate. RUSSIAN JOURNAL OF ORGANIC CHEMISTRY 2018. [DOI: 10.1134/s1070428018090117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Torgov V, Danilov L, Utkina N, Veselovsky V, Brockhausen I. Synthesis of P 1-(11-phenoxyundecyl)-P 2-(2-acetamido-2-deoxy-3-O-α-D-rhamnopyranosyl-α-D-glucopyranosyl) diphosphate and P 1-(11-phenoxyundecyl)-P 2-(2-acetamido-2-deoxy-3-O-β-D-galactopyranosyl-α-D-galactopyranosyl) diphosphate for the investigation of biosynthesis of O-antigenic polysaccharides in Pseudomonas aeruginosa and Escherichia coli O104. Carbohydr Res 2017; 453-454:19-25. [PMID: 29107815 DOI: 10.1016/j.carres.2017.10.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 10/24/2017] [Accepted: 10/24/2017] [Indexed: 10/18/2022]
Abstract
Two new phenoxyundecyl diphosphate sugars were synthesized for the first time: P1-(11-phenoxyundecyl)-P2- (2-acetamido-2-deoxy-3-O-α-D-rhamnopyranosyl-α-D-glucopyranosyl) diphosphate and P1-(11-phenoxyundecyl)-P2-(2-acetamido-2-deoxy-3-O-β-D-galactopyranosyl-α-D-galactopyranosyl) diphosphate to study the third step of biosynthesis of the repeating units of O-antigenic polysaccharides in Pseudomonas aeruginosa and E.coli O104 respectively.
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Affiliation(s)
- Vladimir Torgov
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Leonid Danilov
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Natalia Utkina
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia.
| | - Vladimir Veselovsky
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Inka Brockhausen
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Canada
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Identification and biochemical characterization of WbwB, a novel UDP-Gal: Neu5Ac-R α1,4-galactosyltransferase from the intestinal pathogen Escherichia coli serotype O104. Glycoconj J 2017; 35:65-76. [PMID: 29063990 DOI: 10.1007/s10719-017-9799-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 09/11/2017] [Accepted: 09/13/2017] [Indexed: 02/08/2023]
Abstract
The intestinal pathogen Escherichia coli serotype O104:H4 (ECO104) can cause bloody diarrhea and haemolytic uremic syndrome. The ECO104 O antigen has the unique repeating unit structure [4Galα1-4Neu5,7,9Ac3α2-3Galβ1-3GalNAcβ1-], which includes the mammalian sialyl-T antigen as an internal structure. Previously, we identified WbwC from ECO104 as the β3Gal-transferase that synthesizes the T antigen, and showed that α3-sialyl-transferase WbwA transfers sialic acid to the T antigen. Here we identify the wbwB gene product as a unique α1,4-Gal-transferase WbwB that transfers Gal from UDP-Gal to the terminal sialic acid residue of Neu5Acα2-3Galβ1-3GalNAcα-diphosphate-lipid acceptor. NMR analysis of the WbwB enzyme reaction product indicated that Galα1-4Neu5Acα2-3Galβ1-3GalNAcα-diphosphate-lipid was synthesized. WbwB from ECO104 has a unique acceptor specificity for terminal sialic acid as well as the diphosphate group in the acceptor. The characterization studies showed that WbwB does not require divalent metal ion as a cofactor. Mutagenesis identified Lys243 within an RKR motif and both Glu315 and Glu323 of the fourth EX7E motif as essential for the activity. WbwB is the final glycosyltransferase in the biosynthesis pathway of the ECO104 antigen repeating unit. This work contributes to knowledge of the biosynthesis of bacterial virulence factors.
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Bosco M, Massarweh A, Iatmanen-Harbi S, Bouhss A, Chantret I, Busca P, Moore SEH, Gravier-Pelletier C. Synthesis and biological evaluation of chemical tools for the study of Dolichol Linked Oligosaccharide Diphosphatase (DLODP). Eur J Med Chem 2016; 125:952-964. [PMID: 27769035 DOI: 10.1016/j.ejmech.2016.10.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 09/19/2016] [Accepted: 10/07/2016] [Indexed: 01/16/2023]
Abstract
Citronellyl- and solanesyl-based dolichol linked oligosaccharide (DLO) analogs were synthesized and tested along with undecaprenyl compounds for their ability to inhibit the release of [3H]OSP from [3H]DLO by mammalian liver DLO diphosphatase activity. Solanesyl (C45) and undecaprenyl (C55) compounds were 50-500 fold more potent than their citronellyl (C10)-based counterparts, indicating that the alkyl chain length is important for activity. The relative potency of the compounds within the citronellyl series was different to that of the solanesyl series with citronellyl diphosphate being 2 and 3 fold more potent than citronellyl-PP-GlcNAc2 and citronellyl-PP-GlcNAc, respectively; whereas solanesyl-PP-GlcNAc and solanesyl-PP-GlcNAc2 were 4 and 8 fold more potent, respectively, than solanesyl diphosphate. Undecaprenyl-PP-GlcNAc and bacterial Lipid II were 8 fold more potent than undecaprenyl diphosphate at inhibiting the DLODP assay. Therefore, at least for the more hydrophobic compounds, diphosphodiesters are more potent inhibitors of the DLODP assay than diphosphomonoesters. These results suggest that DLO rather than dolichyl diphosphate might be a preferred substrate for the DLODP activity.
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Affiliation(s)
- Michaël Bosco
- Université Paris Descartes, CICB-Paris, CNRS UMR 8601, Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, 45 rue des Saints-Pères, 75006, Paris, France
| | - Ahmad Massarweh
- Université Paris Diderot, INSERM U1149, 16 rue Henri Huchard, 75018, Paris, France
| | - Soria Iatmanen-Harbi
- Université Paris Diderot, INSERM U1149, 16 rue Henri Huchard, 75018, Paris, France
| | - Ahmed Bouhss
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette, France
| | - Isabelle Chantret
- Université Paris Diderot, INSERM U1149, 16 rue Henri Huchard, 75018, Paris, France
| | - Patricia Busca
- Université Paris Descartes, CICB-Paris, CNRS UMR 8601, Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, 45 rue des Saints-Pères, 75006, Paris, France
| | - Stuart E H Moore
- Université Paris Diderot, INSERM U1149, 16 rue Henri Huchard, 75018, Paris, France
| | - Christine Gravier-Pelletier
- Université Paris Descartes, CICB-Paris, CNRS UMR 8601, Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, 45 rue des Saints-Pères, 75006, Paris, France.
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Identification and Biochemical Characterization of the Novel α2,3-Sialyltransferase WbwA from Pathogenic Escherichia coli Serotype O104. J Bacteriol 2015; 197:3760-8. [PMID: 26391208 DOI: 10.1128/jb.00521-15] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 09/17/2015] [Indexed: 12/18/2022] Open
Abstract
UNLABELLED The sialyl-T antigen sialylα2-3Galβ1-3GalNAc is a common O-glycan structure in human glycoproteins and is synthesized by sialyltransferase ST3Gal1. The enterohemorrhagic Escherichia coli serotype O104 has the rare ability to synthesize a sialyl-T antigen mimic. We showed here that the wbwA gene of the E. coli O104 antigen synthesis gene cluster encodes an α2,3-sialyltransferase WbwA that transfers sialic acid from CMP-sialic acid to Galβ1-3GalNAcα-diphosphate-lipid acceptor. Nuclear magnetic resonance (NMR) analysis of purified WbwA enzyme reaction product indicated that the sialyl-T antigen sialylα2-3Galβ1-3GalNAcα-diphosphate-lipid was synthesized. We showed that the conserved His-Pro (HP) motif and Glu/Asp residues of two EDG motifs in WbwA are important for the activity. The characterization studies showed that WbwA from E. coli O104 is a monofunctional α2,3-sialyltransferase and is distinct from human ST3Gal1 as well as all other known sialyltransferases due to its unique acceptor specificity. This work contributes to knowledge of the biosynthesis of bacterial virulence factors. IMPORTANCE This is the first characterization of a sialyltransferase involved in the synthesis of an O antigen in E. coli. The enzyme contributes to the mimicry of human sialyl-T antigen and has unique substrate specificity but very little sequence identity to other sialyltransferases. Thus, the bacterial sialyltransferase is related to the human counterpart only by the similarity of biochemical activity.
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Vinnikova AN, Torgov VI, Utkina NS, Veselovsky VV, Druzhinina TN, Wang S, Danilov LL. [The synthesis of P1-[11-(anthracen-9-ylmethoxy)undecyl]-P2(2-Acetamido-2-deoxy-α-D-glucopyranosyl) diphosphate and the study of its acceptor properties in the enzymic reaction catalyzed by D-rhamnosyltransferase from Pseudomonas aeruginosa]. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2015; 41:121-3. [PMID: 26050480 DOI: 10.1134/s106816201501015x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
P1-[11-(Anthracen-9-ylmethoxy)undecyl]-P2-(2-acetamido-2-deoxy-α-D-glucopyranosyl) diphosphate, a fluorescent derivative of undecyl diphosphate 2-acetamido-2-deoxyglucose, was chemically synthesized. The ability of the compound to serve as acceptor substrate of D-rhamnose residue in the enzymatic reaction catalyzed by D-rhamnosyltransferase from Pseudomonas aeruginosa PAO1 was demonstrated.
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11
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Vinnikova AN, Demirova KA, Druzhinina TN, Veselovsky VV. New fluorescent analogs of bacterial undecaprenyldiphosphate galactose. Russ Chem Bull 2015. [DOI: 10.1007/s11172-015-0843-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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12
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Brockhausen I. Crossroads between Bacterial and Mammalian Glycosyltransferases. Front Immunol 2014; 5:492. [PMID: 25368613 PMCID: PMC4202792 DOI: 10.3389/fimmu.2014.00492] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Accepted: 09/23/2014] [Indexed: 11/26/2022] Open
Abstract
Bacterial glycosyltransferases (GT) often synthesize the same glycan linkages as mammalian GT; yet, they usually have very little sequence identity. Nevertheless, enzymatic properties, folding, substrate specificities, and catalytic mechanisms of these enzyme proteins may have significant similarity. Thus, bacterial GT can be utilized for the enzymatic synthesis of both bacterial and mammalian types of complex glycan structures. A comparison is made here between mammalian and bacterial enzymes that synthesize epitopes found in mammalian glycoproteins, and those found in the O antigens of Gram-negative bacteria. These epitopes include Thomsen–Friedenreich (TF or T) antigen, blood group O, A, and B, type 1 and 2 chains, Lewis antigens, sialylated and fucosylated structures, and polysialic acids. Many different approaches can be taken to investigate the substrate binding and catalytic mechanisms of GT, including crystal structure analyses, mutations, comparison of amino acid sequences, NMR, and mass spectrometry. Knowledge of the protein structures and functions helps to design GT for specific glycan synthesis and to develop inhibitors. The goals are to develop new strategies to reduce bacterial virulence and to synthesize vaccines and other biologically active glycan structures.
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Affiliation(s)
- Inka Brockhausen
- Department of Medicine, Queen's University , Kingston, ON , Canada ; Department of Biomedical and Molecular Sciences, Queen's University , Kingston, ON , Canada
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Kalynych S, Morona R, Cygler M. Progress in understanding the assembly process of bacterial O-antigen. FEMS Microbiol Rev 2014; 38:1048-65. [DOI: 10.1111/1574-6976.12070] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Revised: 01/28/2014] [Accepted: 02/24/2014] [Indexed: 12/20/2022] Open
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Wang S, Czuchry D, Liu B, Vinnikova AN, Gao Y, Vlahakis JZ, Szarek WA, Wang L, Feng L, Brockhausen I. Characterization of two UDP-Gal:GalNAc-diphosphate-lipid β1,3-galactosyltransferases WbwC from Escherichia coli serotypes O104 and O5. J Bacteriol 2014; 196:3122-33. [PMID: 24957618 PMCID: PMC4135647 DOI: 10.1128/jb.01698-14] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 06/12/2014] [Indexed: 11/20/2022] Open
Abstract
Escherichia coli displays O antigens on the outer membrane that play an important role in bacterial interactions with the environment. The O antigens of enterohemorrhagic E. coli O104 and O5 contain a Galβ1-3GalNAc disaccharide at the reducing end of the repeating unit. Several other O antigens contain this disaccharide, which is identical to the mammalian O-glycan core 1 or the cancer-associated Thomsen-Friedenreich (TF) antigen. We identified the wbwC genes responsible for the synthesis of the disaccharide in E. coli serotypes O104 and O5. To functionally characterize WbwC, an acceptor substrate analog, GalNAcα-diphosphate-phenylundecyl, was synthesized. WbwC reaction products were isolated by high-pressure liquid chromatography and analyzed by mass spectrometry, nuclear magnetic resonance, galactosidase and O-glycanase digestion, and anti-TF antibody. The results clearly showed that the Galβ1-3GalNAcα linkage was synthesized, confirming WbwCECO104 and WbwCECO5 as UDP-Gal:GalNAcα-diphosphate-lipid β1,3-Gal-transferases. Sequence analysis revealed a conserved DxDD motif, and mutagenesis showed the importance of these Asp residues in catalysis. The purified enzymes require divalent cations (Mn(2+)) for activity and are specific for UDP-Gal and GalNAc-diphosphate lipid substrates. WbwC was inhibited by bis-imidazolium salts having aliphatic chains of 18 to 22 carbons. This work will help to elucidate mechanisms of polysaccharide synthesis in pathogenic bacteria and provide technology for vaccine synthesis.
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Affiliation(s)
- Shuo Wang
- Department of Medicine and Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | - Diana Czuchry
- Department of Medicine and Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | - Bin Liu
- TEDA School of Biological Sciences and Biotechnology, Nankai University, Tianjin, China
| | - Anna N Vinnikova
- Department of Medicine and Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | - Yin Gao
- Department of Medicine and Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | - Jason Z Vlahakis
- Department of Chemistry, Queen's University, Kingston, Ontario, Canada
| | - Walter A Szarek
- Department of Chemistry, Queen's University, Kingston, Ontario, Canada
| | - Lei Wang
- TEDA School of Biological Sciences and Biotechnology, Nankai University, Tianjin, China
| | - Lu Feng
- TEDA School of Biological Sciences and Biotechnology, Nankai University, Tianjin, China
| | - Inka Brockhausen
- Department of Medicine and Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
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15
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Danilov LL, Balagurova NM, Vinnikova AN, Utkina NS, Torgov VI, Kalinchuk NA, Druzhinina TN, Veselovsky VV. [Synthesis of 11-[(2-pyridyl)amino]- and 11-[(9-anthracenylcarbonyl)amino]undecyl phosphate and investigation of their acceptor properties in the enzymic reaction catalyzed by galactosylphosphotransferases from Salmonella]. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2014; 40:99-107. [PMID: 25898728 DOI: 10.1134/s1068162014010038] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
11-[(2-Pyridyl)amino]undecyl phosphate and 11-[(9-anthracenylcarbonyl)amino]undecyl phosphate were chemically synthesized. The abiliy of these new fluorescent derivatives of undecyl phosphate to serve as acceptor substrate of galactosyl phosphate residue in the enzymic reaction catalyzed by galactosylphosphotransferase from Salmonella anatum or Salmonella newport membrane preparation was demonstrated.
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Wang S, Tanaka H, Hindsgaul O, Lam JS, Brockhausen I. A convenient synthesis of GDP-D-rhamnose: the donor substrate for D-rhamnosyltransferase WbpZ from Pseudomonas aeruginosa PAO1. Bioorg Med Chem Lett 2013; 23:3491-5. [PMID: 23664878 DOI: 10.1016/j.bmcl.2013.04.051] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 04/14/2013] [Accepted: 04/22/2013] [Indexed: 10/26/2022]
Abstract
Gram negative bacteria have lipopolysaccharides (LPS) that are critical for their survival. LPS molecules are composed of antigenic exopolysaccharide chains (O antigens). We are interested in discovering the enzymes involved in the biosynthesis of O antigens in Pseudomonas aeruginosa. The common polysaccharide antigen contains α-linked D-rhamnose residues. We have now synthesized GDP-D-rhamnose by a convenient synthesis in aqueous solution, and have shown that it can be used without extensive purification as the donor substrate for D-rhamnosyltransferase (WbpZ) from the P. aeruginosa strain PAO1. The availability of this nucleotide sugar preparation allows for characterization of D-rhamnosyltransferases.
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Affiliation(s)
- Shuo Wang
- Department of Medicine, Queen's University, Kingston, Ontario, Canada K7L 3N6
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Gao Y, Vinnikova A, Brockhausen I. Functional identification of bacterial glucosyltransferase WbdN. Methods Mol Biol 2013; 1022:199-214. [PMID: 23765664 DOI: 10.1007/978-1-62703-465-4_16] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The outer membrane of gram-negative bacteria is stabilized by lipopolysaccharides (LPS). The O-antigenic polysaccharides of LPS are composed of repeating units that are exposed to and can interact with the environment. The glycosyltransferases that assemble these repeating units are encoded by the O-antigen gene cluster and utilize undecaprenol-phosphate-linked intermediates as natural acceptor substrates, and nucleotide sugars as donor substrates on the cytoplasmic face of the inner membrane. Many of the glycosyltransferase genes are known but the enzymatic functions of most of them remain to be identified. We describe here how the function of a recombinant glucosyltransferase WbdN from Escherichia coli O157 can be determined by NMR analysis of the enzyme product, using a synthetic acceptor substrate analog. A fluorescent acceptor substrate analog can be used in highly sensitive enzyme assays that allow the characterization of enzyme activity without the use of radioactive nucleotide sugar donor substrates.
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Affiliation(s)
- Yin Gao
- Department of Medicine, Division of Rheumatology, Queen's University, Kingston, Ontario, Canada
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Synthesis of a fluorescent acceptor substrate for glycosyltransferases involved in the assembly of O-antigens of enterohemorrhagic Escherichia coli O157 and O5. Carbohydr Res 2013; 366:17-24. [DOI: 10.1016/j.carres.2012.11.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Revised: 11/13/2012] [Accepted: 11/15/2012] [Indexed: 11/23/2022]
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19
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Utkina NS, Danilov LL, Veselovskiĭ VV, Torgov VI, Druzhinina TN. [Synthesis of p(1)-(11-phenoxyundecyl)-P(2)-(alpha-D-galactopyranosyl) diphosphate and p(1)-(11-phenoxyundecyl)-P(2)-(alpha-D-glucopyranosyl) diphosphate; assay of their acceptor properties for mannosyl residue in the enzmic reaction catalyzed by mannosyltransferase from Salmonella newport]. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2012. [PMID: 23189561 DOI: 10.1134/s1068162012040140] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
P(1)-(Phenoxyundecyl)-P(2)-(alpha-D-galactopyranosyl) diphosphate as well as P(1)-(11-phenoxyundecyl)-P(2)-(alpha-D-glucopyranosyl) diphosphate are newly synthesized and their ability to serve as substrate-acceptor of mannosyl residue in enzymic reaction catalyzed by mannosyltransferase from Salmonella newport membrane preparation is investigated. The possibility ofgalactosyl-containing derivative to serve as mannosyl acceptor from GDP-Man is established whereas glucosyl-containing compound is inactive in this process.
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20
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Gao Y, Liu B, Strum S, Schutzbach JS, Druzhinina TN, Utkina NS, Torgov VI, Danilov LL, Veselovsky VV, Vlahakis JZ, Szarek WA, Wang L, Brockhausen I. Biochemical characterization of WbdN, a β1,3-glucosyltransferase involved in O-antigen synthesis in enterohemorrhagic Escherichia coli O157. Glycobiology 2012; 22:1092-102. [PMID: 22556057 DOI: 10.1093/glycob/cws081] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The enterohemorrhagic O157 strain of Escherichia coli, which is one of the most well-known bacterial pathogens, has an O-antigen repeating unit structure with the sequence [-2-d-Rha4NAcα1-3-l-Fucα1-4-d-Glcβ1-3-d-GalNAcα1-]. The O-antigen gene cluster of E. coli O157 contains the genes responsible for the assembly of this repeating unit and includes wbdN. In spite of cloning many O-antigen genes, biochemical characterization has been done on very few enzymes involved in O-antigen synthesis. In this work, we expressed the wbdN gene in E. coli BL21, and the His-tagged protein was purified. WbdN activity was characterized using the donor substrate UDP-[(14)C]Glc and the synthetic acceptor substrate GalNAcα-O-PO(3)-PO(3)-(CH(2))(11)-O-Ph. The enzyme product was isolated by high pressure liquid chromatography, and mass spectrometry showed that one Glc residue was transferred to the acceptor by WbdN. Nuclear magnetic resonance analysis of the product structure indicated that Glc was β1-3 linked to GalNAc. WbdN contains a conserved DxD motif and requires divalent metal ions for full activity. WbdN activity has an optimal pH between 7 and 8 and is highly specific for UDP-Glc as the donor substrate. GalNAcα derivatives lacking the diphosphate group were inactive as substrates, and the enzyme did not transfer Glc to GlcNAcα-O-PO(3)-PO(3)-(CH(2))(11)-O-Ph. Our results illustrate that WbdN is a specific UDP-Glc:GalNAcα-diphosphate-lipid β1,3-Glc-transferase. The enzyme is a target for the development of inhibitors to block O157-antigen synthesis.
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Affiliation(s)
- Yin Gao
- Department of Medicine, Division of Rheumatology, Queen's University, Kingston, Ontario, Canada
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21
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Harvey DJ. Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: an update for the period 2005-2006. MASS SPECTROMETRY REVIEWS 2011; 30:1-100. [PMID: 20222147 DOI: 10.1002/mas.20265] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
This review is the fourth update of the original review, published in 1999, on the application of MALDI mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2006. The review covers fundamental studies, fragmentation of carbohydrate ions, method developments, and applications of the technique to the analysis of different types of carbohydrate. Specific compound classes that are covered include carbohydrate polymers from plants, N- and O-linked glycans from glycoproteins, glycated proteins, glycolipids from bacteria, glycosides, and various other natural products. There is a short section on the use of MALDI-TOF mass spectrometry for the study of enzymes involved in glycan processing, a section on industrial processes, particularly the development of biopharmaceuticals and a section on the use of MALDI-MS to monitor products of chemical synthesis of carbohydrates. Large carbohydrate-protein complexes and glycodendrimers are highlighted in this final section.
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Affiliation(s)
- David J Harvey
- Department of Biochemistry, Oxford Glycobiology Institute, University of Oxford, Oxford OX1 3QU, UK.
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22
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An undecaprenyl phosphate analog containing the phenoxy group at the ω-end of the oligoisoprene chain. Russ Chem Bull 2010. [DOI: 10.1007/s11172-010-0231-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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23
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Utkina NS, Danilov LL, Druzhinina TN, Veselovskii VV. Simple synthesis of P 1-(11-phenoxyundecyl)-P 2-(2-acetamido-2-deoxy-α-D-galactopyranosyl) diphosphate. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2010; 36:853-5. [DOI: 10.1134/s1068162010060166] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Biochemical characterization of UDP-Gal:GlcNAc-pyrophosphate-lipid β-1,4-Galactosyltransferase WfeD, a new enzyme from Shigella boydii type 14 that catalyzes the second step in O-antigen repeating-unit synthesis. J Bacteriol 2010; 193:449-59. [PMID: 21057010 DOI: 10.1128/jb.00737-10] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The O antigen is the outer part of the lipopolysaccharide (LPS) in the outer membrane of Gram-negative bacteria and contains many repeats of an oligosaccharide unit. It contributes to antigenic variability and is essential to the full function and virulence of bacteria. Shigella is a Gram-negative human pathogen that causes diarrhea in humans. The O antigen of Shigella boydii type 14 consists of repeating oligosaccharide units with the structure [→6-d-Galpα1→4-d-GlcpAβ1→6-d-Galpβ1→4-d-Galpβ1→4-d-GlcpNAcβ1→]n. The wfeD gene in the O-antigen gene cluster of Shigella boydii type 14 was proposed to encode a galactosyltransferase (GalT) involved in O-antigen synthesis. We confirmed here that the wfeD gene product is a β4-GalT that synthesizes the Galβ1-4GlcNAcα-R linkage. WfeD was expressed in Escherichia coli, and the activity was characterized by using UDP-[³H]Gal as the donor substrate as well as the synthetic acceptor substrate GlcNAcα-pyrophosphate-(CH₂)₁₁-O-phenyl. The enzyme product was analyzed by liquid chromatography-mass spectrometry (LC-MS), high-performance liquid chromatography (HPLC), nuclear magnetic resonance (NMR), and galactosidase digestion. The enzyme was shown to be specific for the UDP-Gal donor substrate and required pyrophosphate in the acceptor substrate. Divalent metal ions such as Mn²(+), Ni²(+), and, surprisingly, also Pb²(+) enhanced the enzyme activity. Mutational analysis showed that the Glu101 residue within a DxD motif is essential for activity, possibly by forming the catalytic nucleophile. The Lys211 residue was also shown to be required for activity and may be involved in the binding of the negatively charged acceptor substrate. Our study revealed that the β4-GalT WfeD is a novel enzyme that has virtually no sequence similarity to mammalian β4-GalT, although it catalyzes a similar reaction.
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25
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Druzhinina TN, Danilov LL, Torgov VI, Utkina NS, Balagurova NM, Veselovsky VV, Chizhov AO. 11-Phenoxyundecyl phosphate as a 2-acetamido-2-deoxy-α-d-glucopyranosyl phosphate acceptor in O-antigen repeating unit assembly of Salmonella arizonae O:59. Carbohydr Res 2010; 345:2636-40. [PMID: 20974465 DOI: 10.1016/j.carres.2010.09.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Revised: 09/15/2010] [Accepted: 09/18/2010] [Indexed: 10/19/2022]
Abstract
A synthesis of 11-phenoxyundecyl phosphate and its biochemical transformation (using GlcNAc-P transferase from Salmonella arizonae O:59 membranes catalysing transfer of GlcNc-phosphate from UDP-GlcNAc on lipid-phosphate) into P(1)-11-phenoxyundecyl, P(2)-2-acetamido-2-deoxy-α-D-glucopyranosyl diphosphate are described.
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Affiliation(s)
- Tatyana N Druzhinina
- N. D. Zelinsky Institute of Organic Сhemistry, Russian Academy of Sciences, Moscow, Russia.
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26
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Riley JG, Xu C, Brockhausen I. Synthesis of acceptor substrate analogs for the study of glycosyltransferases involved in the second step of the biosynthesis of O-antigen repeating units. Carbohydr Res 2010; 345:586-97. [DOI: 10.1016/j.carres.2009.12.022] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2009] [Revised: 12/21/2009] [Accepted: 12/22/2009] [Indexed: 11/15/2022]
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27
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Han W, Li L, Pettit N, Yi W, Woodward R, Liu X, Guan W, Bhatt V, Song JK, Wang PG. In vitro reconstitution of Escherichia coli O86 O antigen repeating unit. Methods Mol Biol 2010; 600:93-110. [PMID: 19882123 DOI: 10.1007/978-1-60761-454-8_7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Polysaccharides constitute a major component of the bacterial cell surface. They play critical roles in the interactions between bacteria and the host environments, and consequently contribute to the virulence of pathogens. The lipopolysaccharide (LPS) found on the surface of gram-negative bacteria consists of three parts: lipid A, a core oligosaccharide, and the O antigen. The O antigen is the outermost part of LPS and contains multiple oligosaccharide repeating units. Biosynthesis of the O-repeating unit is the first committed step in LPS biosynthesis. We sequenced and characterized the O-antigen biosynthetic gene cluster of Escherichia coli serotype O86. Four glycosyltransferases encoded by the genes within the cluster were cloned and overexpressed. In vitro reconstitution of the O-repeating unit of E. coli 086 was achieved via using these enzymes.
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Affiliation(s)
- Weiqing Han
- Departments of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA
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28
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Danilov LL, Veselovskiĭ VV, Balagurova NM, Druzhinina TN. [Synthesis of 11-phenoxyundecyl phosphate and its use as an acceptor substrate in the reaction with UDP-GlcNAc : polyprenyl phosphate GlcNAc-phosphotransferase from Salmonella arizona O:59]. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2009; 35:431-2. [PMID: 19621060 DOI: 10.1134/s1068162009030169] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A new scheme of synthesis of 11-phenoxyundecyl phosphate from 11-bromoundecanoic acid was suggested for its ability to react as an acceptor of 2-acetamido-2-deoxy-alpha-D-glucopyranosyl phosphate in a reaction catalyzed by UDP-N-acetylglucosamine : polyprenyl phosphate N-acetylglucosamine phosphotransferase from Salmonella arizona O:59.
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29
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Brockhausen I, Riley JG, Joynt M, Yang X, Szarek WA. Acceptor substrate specificity of UDP-Gal: GlcNAc-R β1,3-galactosyltransferase (WbbD) from Escherichia coli O7:K1. Glycoconj J 2008; 25:663-73. [DOI: 10.1007/s10719-008-9127-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2008] [Revised: 03/18/2008] [Accepted: 03/20/2008] [Indexed: 10/22/2022]
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30
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Characterization of two beta-1,3-glucosyltransferases from Escherichia coli serotypes O56 and O152. J Bacteriol 2008; 190:4922-32. [PMID: 18487334 DOI: 10.1128/jb.00160-08] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The O antigens of outer membrane-bound lipopolysaccharides (LPS) in gram-negative bacteria are oligosaccharides consisting of repeating units with various structures and antigenicities. The O56 and O152 antigens of Escherichia coli both contain a Glc-beta1-3-GlcNAc linkage within the repeating unit. We have cloned and identified the genes (wfaP in O56 and wfgD in O152) within the two O-antigen gene clusters that encode glucosyltransferases involved in the synthesis of this linkage. A synthetic substrate analog of the natural acceptor substrate undecaprenol-pyrophosphate-lipid [GlcNAc-alpha-PO3-PO3-(CH2)11-O-phenyl] was used as an acceptor and UDP-Glc as a donor substrate to demonstrate that both wfgD and wfaP encode glucosyltransferases. Enzyme products from both glucosyltransferases were isolated by high-pressure liquid chromatography and analyzed by nuclear magnetic resonance. The spectra showed the expected Glc-beta1-3-GlcNAc linkage in the products, confirming that both WfaP and WfgD are forms of UDP-Glc: GlcNAc-pyrophosphate-lipid beta-1,3-glucosyltransferases. Both WfaP and WfgD have a DxD sequence, which is proposed to interact with phosphate groups of the nucleotide donor through the coordination of a metal cation, and a short hydrophobic sequence at the C terminus that may help to associate the enzymes with the inner membrane. We showed that the enzymes have similar properties and substrate recognition. They both require a divalent cation (Mn2+ or Mg2+) for activity, are deactivated by detergents, have a broad pH optimum, and require the pyrophosphate-sugar linkage in the acceptor substrate for full activity. Substrates lacking phosphate or pyrophosphate linked to GlcNAc were inactive. The length of the aliphatic chain of acceptor substrates also contributes to the activity.
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31
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Brockhausen I, Larsson EA, Hindsgaul O. A very simple synthesis of GlcNAc-α-pyrophosphoryl-decanol: A substrate for the assay of a bacterial galactosyltransferase. Bioorg Med Chem Lett 2008; 18:804-7. [DOI: 10.1016/j.bmcl.2007.11.031] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2007] [Revised: 11/07/2007] [Accepted: 11/09/2007] [Indexed: 11/17/2022]
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32
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Bhavsar AP, Brown ED. Cell wall assembly in Bacillus subtilis: how spirals and spaces challenge paradigms. Mol Microbiol 2007; 60:1077-90. [PMID: 16689786 DOI: 10.1111/j.1365-2958.2006.05169.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Although the bacterial cell wall has been the subject of decades of investigation, recent studies continue to generate novel and controversial models of its synthesis and assembly. Here we compare and contrast the transcompartmental biosyntheses of peptidoglycan and teichoic acid in Bacillus subtilis. In addition, the current paradigms of B. subtilis wall assembly and structure are distinguished from emerging models of murein insertion and organization. We discuss evidence for the directed, cytoskeleton-dependent insertion of nascent peptidoglycan and the existence of a periplasmic compartment. Furthermore, we summarize the challenges these findings represent to the existing paradigm of murein insertion. Finally, motivated by these new developments, we discuss outstanding issues that remain to be addressed and suggest research directions that may contribute to a better understanding of cell wall assembly in B. subtilis.
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Affiliation(s)
- Amit P Bhavsar
- Antimicrobial Research Centre and Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada
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33
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Yi W, Yao Q, Zhang Y, Motari E, Lin S, Wang PG. The wbnH gene of Escherichia coli O86:H2 encodes an α-1,3-N-acetylgalactosaminyl transferase involved in the O-repeating unit biosynthesis. Biochem Biophys Res Commun 2006; 344:631-9. [PMID: 16630548 DOI: 10.1016/j.bbrc.2006.03.181] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2006] [Accepted: 03/24/2006] [Indexed: 11/19/2022]
Abstract
O-repeating unit biosynthesis is the first committed step in lipopolysaccharide (LPS) biosynthesis in a variety of gram-negative bacteria. The wbnH gene was previously proposed to encode a glycosyltransferase involved in O-repeating unit synthesis in Escherichia coli O86:H2 strain. In this work, we provide biochemical evidence to show that wbnH encodes a N-acetylgalactosaminyl transferase (GalNAcT) that catalyzes the transfer of GalNAc from UDP-GalNAc to the GalNAc-pyrophosphate-lipid acceptor. WbnH activity was characterized using a synthetic acceptor substrate GalNAc alpha-PP-O(CH2)11-OPh. The resulting disaccharide product GalNAc-alpha-1,3-GalNAc alpha-PP-O(CH2)11-OPh was analyzed by LC-MS and NMR spectroscopy. Substrate specificity study indicates that pyrophosphate and hydrophobic lipid moiety are structural requirements for WbnH activity. Divalent metal cations are not required for enzyme catalysis, suggesting WbnH belongs to glycosyltransferase GT-B superfamily. Our results complete the characterization of O86 O-unit assembly pathway, and provide the access of chemically defined O-unit substrates for the further investigation of O-antigen biosynthetic mechanism.
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Affiliation(s)
- Wen Yi
- Department of Chemistry, The Ohio State University, Columbus, OH 43210, USA
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Riley JG, Menggad M, Montoya-Peleaz PJ, Szarek WA, Marolda CL, Valvano MA, Schutzbach JS, Brockhausen I. The wbbD gene of E. coli strain VW187 (O7:K1) encodes a UDP-Gal: GlcNAc{alpha}-pyrophosphate-R {beta}1,3-galactosyltransferase involved in the biosynthesis of O7-specific lipopolysaccharide. Glycobiology 2004; 15:605-13. [PMID: 15625181 DOI: 10.1093/glycob/cwi038] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In this work, we demonstrate that the wbbD gene of the O7 lipopolysaccharide (LPS) biosynthesis cluster in Escherichia coli strain VW187 (O7:K1) encodes a galactosyltransferase involved in the synthesis of the O7-polysaccharide repeating unit. The galactosyltransferase catalyzed the transfer of Gal from UDP-Gal to the GlcNAc residue of a GlcNAc-pyrophosphate-lipid acceptor. A mutant strain with a defective wbbD gene was unable to form O7 LPS and lacked this specific galactosyltransferase activity. The normal phenotype was restored by complementing the mutant with the cloned wbbD gene. To characterize the WbbD galactosyltransferase, we used a novel acceptor substrate containing GlcNAcalpha-pyrophosphate covalently bound to a hydrophobic phenoxyundecyl moiety (GlcNAc alpha-O-PO(3)-PO(3)-(CH(2))(11)-O-phenyl). The WbbD galactosyltransferase had optimal activity at pH 7 in the presence of 2.5 mM MnCl(2). Detergents in the assay did not increase glycosyl transfer. Digestion of enzyme product by highly purified bovine testicular beta-galactosidase demonstrated a beta-linkage. Cleavage of product by pyrophosphatase and phosphatase, followed by HPLC and NMR analyses, revealed a disaccharide with the structure Gal beta1-3GlcNAc. Our results conclusively demonstrate that WbbD is a UDP-Gal: GlcNAcalpha-pyrophosphate-R beta1,3-galactosyltransferase and suggest that the novel synthetic glycolipid acceptor may be generally applicable to characterize other bacterial glycosyltransferases.
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Affiliation(s)
- John G Riley
- Department of Medicine, Department of Biochemistry, The Arthritis Centre and Human Mobility Research Centre, Queen's University, Kingston General Hospital, Kingston, Ontario K7L 2V7, Canada
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