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Thai VC, Stubbs KA, Sarkar-Tyson M, Kahler CM. Phosphoethanolamine Transferases as Drug Discovery Targets for Therapeutic Treatment of Multi-Drug Resistant Pathogenic Gram-Negative Bacteria. Antibiotics (Basel) 2023; 12:1382. [PMID: 37760679 PMCID: PMC10525099 DOI: 10.3390/antibiotics12091382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 08/25/2023] [Accepted: 08/26/2023] [Indexed: 09/29/2023] Open
Abstract
Antibiotic resistance caused by multidrug-resistant (MDR) bacteria is a major challenge to global public health. Polymyxins are increasingly being used as last-in-line antibiotics to treat MDR Gram-negative bacterial infections, but resistance development renders them ineffective for empirical therapy. The main mechanism that bacteria use to defend against polymyxins is to modify the lipid A headgroups of the outer membrane by adding phosphoethanolamine (PEA) moieties. In addition to lipid A modifying PEA transferases, Gram-negative bacteria possess PEA transferases that decorate proteins and glycans. This review provides a comprehensive overview of the function, structure, and mechanism of action of PEA transferases identified in pathogenic Gram-negative bacteria. It also summarizes the current drug development progress targeting this enzyme family, which could reverse antibiotic resistance to polymyxins to restore their utility in empiric therapy.
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Affiliation(s)
- Van C. Thai
- The Marshall Center for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, Crawley, WA 6009, Australia; (V.C.T.); (M.S.-T.)
| | - Keith A. Stubbs
- School of Molecular Sciences, University of Western Australia, Crawley, WA 6009, Australia;
| | - Mitali Sarkar-Tyson
- The Marshall Center for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, Crawley, WA 6009, Australia; (V.C.T.); (M.S.-T.)
| | - Charlene M. Kahler
- The Marshall Center for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, Crawley, WA 6009, Australia; (V.C.T.); (M.S.-T.)
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Zhang Y, Jen FEC, Edwards JL, Jennings MP. Analysis of Bacterial Phosphorylcholine-Related Genes Reveals an Association between Type-Specific Biosynthesis Pathways and Biomolecules Targeted for Phosphorylcholine Modification. Microbiol Spectr 2023; 11:e0158323. [PMID: 37436144 PMCID: PMC10434233 DOI: 10.1128/spectrum.01583-23] [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] [Received: 04/14/2023] [Accepted: 06/08/2023] [Indexed: 07/13/2023] Open
Abstract
Many bacterial surface proteins and carbohydrates are modified with phosphorylcholine (ChoP), which contributes to host mimicry and can also promote colonization and survival in the host. However, the ChoP biosynthetic pathways that are used in bacterial species that express ChoP have not been systematically studied. For example, the well-studied Lic-1 pathway is absent in some ChoP-expressing bacteria, such as Neisseria meningitidis and Neisseria gonorrhoeae. This raises a question as to the origin of the ChoP used for macromolecule biosynthesis in these species. In the current study, we used in silico analyses to identify the potential pathways involved in ChoP biosynthesis in genomes of the 26 bacterial species reported to express a ChoP-modified biomolecule. We used the four known ChoP biosynthetic pathways and a ChoP transferase as search terms to probe for their presence in these genomes. We found that the Lic-1 pathway is primarily associated with organisms producing ChoP-modified carbohydrates, such as lipooligosaccharide. Pilin phosphorylcholine transferase A (PptA) homologs were detected in all bacteria that express ChoP-modified proteins. Additionally, ChoP biosynthesis pathways, such as phospholipid N-methyltransferase (PmtA), phosphatidylcholine synthase (Pcs), or the acylation-dependent phosphatidylcholine biosynthesis pathway, which generate phosphatidylcholine, were also identified in species that produce ChoP-modified proteins. Thus, a major finding of this study is the association of a particular ChoP biosynthetic pathway with a cognate, target ChoP-modified surface factor; i.e., protein versus carbohydrate. This survey failed to identify a known biosynthetic pathway for some species that express ChoP, indicating that a novel ChoP biosynthetic pathway(s) may remain to be identified. IMPORTANCE The modification of bacterial surface virulence factors with phosphorylcholine (ChoP) plays an important role in bacterial virulence and pathogenesis. However, the ChoP biosynthetic pathways in bacteria have not been fully understood. In this study, we used in silico analysis to identify potential ChoP biosynthetic pathways in bacteria that express ChoP-modified biomolecules and found the association between a specific ChoP biosynthesis pathway and the cognate target ChoP-modified surface factor.
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Affiliation(s)
- Yuan Zhang
- Institute for Glycomics, Griffith University, Southport, Australia
| | - Freda E.-C. Jen
- Institute for Glycomics, Griffith University, Southport, Australia
| | - Jennifer L. Edwards
- Center for Microbial Pathogenesis, The Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, Ohio, USA
- Department of Pediatrics, The Ohio State University, Columbus, Ohio, USA
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Fux AC, Casonato Melo C, Michelini S, Swartzwelter BJ, Neusch A, Italiani P, Himly M. Heterogeneity of Lipopolysaccharide as Source of Variability in Bioassays and LPS-Binding Proteins as Remedy. Int J Mol Sci 2023; 24:ijms24098395. [PMID: 37176105 PMCID: PMC10179214 DOI: 10.3390/ijms24098395] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 05/03/2023] [Accepted: 05/05/2023] [Indexed: 05/15/2023] Open
Abstract
Lipopolysaccharide (LPS), also referred to as endotoxin, is the major component of Gram-negative bacteria's outer cell wall. It is one of the main types of pathogen-associated molecular patterns (PAMPs) that are known to elicit severe immune reactions in the event of a pathogen trespassing the epithelial barrier and reaching the bloodstream. Associated symptoms include fever and septic shock, which in severe cases, might even lead to death. Thus, the detection of LPS in medical devices and injectable pharmaceuticals is of utmost importance. However, the term LPS does not describe one single molecule but a diverse class of molecules sharing one common feature: their characteristic chemical structure. Each bacterial species has its own pool of LPS molecules varying in their chemical composition and enabling the aggregation into different supramolecular structures upon release from the bacterial cell wall. As this heterogeneity has consequences for bioassays, we aim to examine the great variability of LPS molecules and their potential to form various supramolecular structures. Furthermore, we describe current LPS quantification methods and the LPS-dependent inflammatory pathway and show how LPS heterogeneity can affect them. With the intent of overcoming these challenges and moving towards a universal approach for targeting LPS, we review current studies concerning LPS-specific binders. Finally, we give perspectives for LPS research and the use of LPS-binding molecules.
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Affiliation(s)
- Alexandra C Fux
- Division of Allergy & Immunology, Department of Biosciences & Medical Biology, Paris Lodron University of Salzburg (PLUS), Hellbrunnerstraße 34, 5020 Salzburg, Austria
- Chemical Biology Department, R&D Reagents, Miltenyi Biotec B.V. & Co. KG, Friedrich-Ebert-Straße 68, 51429 Bergisch Gladbach, Germany
| | - Cristiane Casonato Melo
- Division of Allergy & Immunology, Department of Biosciences & Medical Biology, Paris Lodron University of Salzburg (PLUS), Hellbrunnerstraße 34, 5020 Salzburg, Austria
- Chemical Biology Department, R&D Reagents, Miltenyi Biotec B.V. & Co. KG, Friedrich-Ebert-Straße 68, 51429 Bergisch Gladbach, Germany
| | - Sara Michelini
- Biotechnical Faculty, Department of Biology, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia
| | - Benjamin J Swartzwelter
- Department of Microbiology, Immunology, and Pathology, 1601 Campus Delivery, Colorado State University, Fort Collins, CO 80523, USA
| | - Andreas Neusch
- Experimental Medical Physics, Heinrich-Heine University Düsseldorf, Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Paola Italiani
- Institute of Biochemistry and Cell Biology, Consiglio Nazionale delle Ricerche (CNR), Via P. Castellino 111, 80131 Naples, Italy
- Stazione Zoologica Anton Dohrn (SZN), Villa Comunale, 80121 Naples, Italy
| | - Martin Himly
- Division of Allergy & Immunology, Department of Biosciences & Medical Biology, Paris Lodron University of Salzburg (PLUS), Hellbrunnerstraße 34, 5020 Salzburg, Austria
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Kawai T, Matsumori N, Otsuka K. Recent advances in microscale separation techniques for lipidome analysis. Analyst 2021; 146:7418-7430. [PMID: 34787600 DOI: 10.1039/d1an00967b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
This review paper highlights the recent research on liquid-phase microscale separation techniques for lipidome analysis over the last 10 years, mainly focusing on capillary liquid chromatography (LC) and capillary electrophoresis (CE) coupled with mass spectrometry (MS). Lipids are one of the most important classes of biomolecules which are involved in the cell membrane, energy storage, signal transduction, and so on. Since lipids include a variety of hydrophobic compounds including numerous structural isomers, lipidomes are a challenging target in bioanalytical chemistry. MS is the key technology that comprehensively identifies lipids; however, separation techniques like LC and CE are necessary prior to MS detection in order to avoid ionization suppression and resolve structural isomers. Separation techniques using μm-scale columns, such as a fused silica capillary and microfluidic device, are effective at realizing high-resolution separation. Microscale separation usually employs a nL-scale flow, which is also compatible with nanoelectrospray ionization-MS that achieves high sensitivity. Owing to such analytical advantages, microscale separation techniques like capillary/microchip LC and CE have been employed for more than 100 lipidome studies. Such techniques are still being evolved and achieving further higher resolution and wider coverage of lipidomes. Therefore, microscale separation techniques are promising as the fundamental technology in next-generation lipidome analysis.
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Affiliation(s)
- Takayuki Kawai
- Department of Chemistry, Faculty of Science, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
| | - Nobuaki Matsumori
- Department of Chemistry, Faculty of Science, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
| | - Koji Otsuka
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.
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Fage CD, Brown DB, Boll JM, Keatinge-Clay AT, Trent MS. Crystallographic study of the phosphoethanolamine transferase EptC required for polymyxin resistance and motility in Campylobacter jejuni. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2014; 70:2730-9. [PMID: 25286856 PMCID: PMC4188012 DOI: 10.1107/s1399004714017623] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 07/31/2014] [Indexed: 01/25/2023]
Abstract
The foodborne enteric pathogen Campylobacter jejuni decorates a variety of its cell-surface structures with phosphoethanolamine (pEtN). Modifying lipid A with pEtN promotes cationic antimicrobial peptide resistance, whereas post-translationally modifying the flagellar rod protein FlgG with pEtN promotes flagellar assembly and motility, which are processes that are important for intestinal colonization. EptC, the pEtN transferase required for all known pEtN cell-surface modifications in C. jejuni, is a predicted inner-membrane metalloenzyme with a five-helix N-terminal transmembrane domain followed by a soluble sulfatase-like catalytic domain in the periplasm. The atomic structure of the catalytic domain of EptC (cEptC) was crystallized and solved to a resolution of 2.40 Å. cEptC adopts the α/β/α fold of the sulfatase protein family and harbors a zinc-binding site. A phosphorylated Thr266 residue was observed that was hypothesized to mimic a covalent pEtN-enzyme intermediate. The requirement for Thr266 as well as the nearby residues Asn308, Ser309, His358 and His440 was ascertained via in vivo activity assays on mutant strains. The results establish a basis for the design of pEtN transferase inhibitors.
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Affiliation(s)
- Christopher D. Fage
- Molecular Biosciences, University of Texas at Austin, 1 University Station, Stop A5300, Austin, TX 78712, USA
| | - Dusty B. Brown
- Molecular Biosciences, University of Texas at Austin, 2506 Speedway, Stop A5000, Austin, TX 78613, USA
| | - Joseph M. Boll
- Molecular Biosciences, University of Texas at Austin, 2506 Speedway, Stop A5000, Austin, TX 78613, USA
| | - Adrian T. Keatinge-Clay
- Molecular Biosciences, University of Texas at Austin, 1 University Station, Stop A5300, Austin, TX 78712, USA
| | - M. Stephen Trent
- Molecular Biosciences, University of Texas at Austin, 2506 Speedway, Stop A5000, Austin, TX 78613, USA
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Functional identification of Proteus mirabilis eptC gene encoding a core lipopolysaccharide phosphoethanolamine transferase. Int J Mol Sci 2014; 15:6689-702. [PMID: 24756091 PMCID: PMC4013655 DOI: 10.3390/ijms15046689] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Revised: 03/03/2014] [Accepted: 04/09/2014] [Indexed: 12/13/2022] Open
Abstract
By comparison of the Proteus mirabilis HI4320 genome with known lipopolysaccharide (LPS) phosphoethanolamine transferases, three putative candidates (PMI3040, PMI3576, and PMI3104) were identified. One of them, eptC (PMI3104) was able to modify the LPS of two defined non-polar core LPS mutants of Klebsiella pneumoniae that we use as surrogate substrates. Mass spectrometry and nuclear magnetic resonance showed that eptC directs the incorporation of phosphoethanolamine to the O-6 of l-glycero-d-mano-heptose II. The eptC gene is found in all the P. mirabilis strains analyzed in this study. Putative eptC homologues were found for only two additional genera of the Enterobacteriaceae family, Photobacterium and Providencia. The data obtained in this work supports the role of the eptC (PMI3104) product in the transfer of PEtN to the O-6 of l,d-HepII in P. mirabilis strains.
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Parker MJ, Gomery K, Richard G, MacKenzie CR, Cox AD, Richards JC, Evans SV. Structural basis for selective cross-reactivity in a bactericidal antibody against inner core lipooligosaccharide from Neisseria meningitidis†,‡. Glycobiology 2014; 24:442-9. [DOI: 10.1093/glycob/cwu009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
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Sun Q, Knirel YA, Lan R, Wang J, Senchenkova SN, Jin D, Shashkov AS, Xia S, Perepelov AV, Chen Q, Wang Y, Wang H, Xu J. A novel plasmid-encoded serotype conversion mechanism through addition of phosphoethanolamine to the O-antigen of Shigella flexneri. PLoS One 2012; 7:e46095. [PMID: 23049947 PMCID: PMC3458804 DOI: 10.1371/journal.pone.0046095] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2012] [Accepted: 08/27/2012] [Indexed: 11/19/2022] Open
Abstract
Shigella flexneri is the major pathogen causing bacillary dysentery in developing countries. S. flexneri is divided into at least 16 serotypes based on the combination of antigenic determinants present in the O-antigen. All the serotypes (except for serotype 6) share a basic O-unit containing one N-acetyl-d-glucosamine and three l-rhamnose residues, whereas differences between the serotypes are conferred by phage-encoded glucosylation and/or O-acetylation. Serotype Xv is a newly emerged and the most prevalent serotype in China, which can agglutinate with both MASF IV-1 and 7,8 monoclonal antibodies. The factor responsible for the presence of MASF IV-1 (E1037) epitope has not yet been identified. In this study, we analyzed the LPS structure of serotype Xv strains and found that the MASF IV-1 positive phenotype depends on an O-antigen modification with a phosphoethanolamine (PEtN) group attached at position 3 of one of the rhamnose residues. A plasmid carried gene, lpt-O (LPS phosphoethanolamine transferase for O–antigen), mediates the addition of PEtN for serotype Xv and other MASF IV-1 positive strains. These findings reveal a novel serotype conversion mechanism in S. flexneri and show the necessity of further extension of the serotype classification scheme recognizing the MASF IV-1 positive strains as distinctive subtypes.
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Affiliation(s)
- Qiangzheng Sun
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, China CDC, Changping, Beijing, China
| | - Yuriy A. Knirel
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russian Federation
| | - Ruiting Lan
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
| | - Jianping Wang
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, China CDC, Changping, Beijing, China
| | - Sof’ya N. Senchenkova
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russian Federation
| | - Dong Jin
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, China CDC, Changping, Beijing, China
| | - Alexander S. Shashkov
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russian Federation
| | - Shengli Xia
- Branch for Enteric Disease Control and Prevention, Institute for Infectious Disease Control and Prevention, Henan Center for Disease Control and Prevention, Zhengzhou, China
| | - Andrei V. Perepelov
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russian Federation
| | - Qiang Chen
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, China CDC, Changping, Beijing, China
| | - Yan Wang
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, China CDC, Changping, Beijing, China
| | - Haiyin Wang
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, China CDC, Changping, Beijing, China
| | - Jianguo Xu
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, China CDC, Changping, Beijing, China
- * E-mail:
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Scott NE, Nothaft H, Edwards AVG, Labbate M, Djordjevic SP, Larsen MR, Szymanski CM, Cordwell SJ. Modification of the Campylobacter jejuni N-linked glycan by EptC protein-mediated addition of phosphoethanolamine. J Biol Chem 2012; 287:29384-96. [PMID: 22761430 DOI: 10.1074/jbc.m112.380212] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Campylobacter jejuni is the major worldwide cause of bacterial gastroenteritis. C. jejuni possesses an extensive repertoire of carbohydrate structures that decorate both protein and non-protein surface-exposed structures. An N-linked glycosylation system encoded by the pgl gene cluster mediates the synthesis of a rigidly conserved heptasaccharide that is attached to protein substrates or released as free oligosaccharide in the periplasm. Removal of N-glycosylation results in reduced virulence and impeded host cell attachment. Since the N-glycan is conserved, the N-glycosylation system is also an attractive option for glycoengineering recombinant vaccines in Escherichia coli. To determine whether non-canonical N-glycans are present in C. jejuni, we utilized high throughput glycoproteomics to characterize C. jejuni JHH1 and identified 93 glycosylation sites, including 34 not previously reported. Interrogation of these data allowed the identification of a phosphoethanolamine (pEtN)-modified variant of the N-glycan that was attached to multiple proteins. The pEtN moiety was attached to the terminal GalNAc of the canonical N-glycan. Deletion of the pEtN transferase eptC removed all evidence of the pEtN-glycan but did not globally influence protein reactivity to patient sera, whereas deletion of the pglB oligosaccharyltransferase significantly reduced reactivity. Transfer of eptC and the pgl gene cluster to E. coli confirmed the addition of the pEtN-glycan to a target C. jejuni protein. Significantly reduced, yet above background levels of pEtN-glycan were also observed in E. coli not expressing eptC, suggesting that endogenous E. coli pEtN transferases can mediate the addition of pEtN to N-glycans. The addition of pEtN must be considered in the context of glycoengineering and may alter C. jejuni glycan-mediated structure-function interactions.
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Affiliation(s)
- Nichollas E Scott
- School of Molecular Bioscience, and Discipline of Pathology (School of Medical Sciences), The University of Sydney, Australia 2006
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Mistretta N, Seguin D, Thiébaud J, Vialle S, Blanc F, Brossaud M, Talaga P, Norheim G, Moreau M, Rokbi B. Genetic and structural characterization of L11 lipooligosaccharide from Neisseria meningitidis serogroup A strains. J Biol Chem 2010; 285:19874-83. [PMID: 20421293 DOI: 10.1074/jbc.m110.100636] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The lipooligosaccharide (LOS) of immunotype L11 is unique within serogroup A meningococci. In order to resolve its molecular structure, we conducted LOS genotyping by PCR analysis of genes responsible for alpha-chain sugar addition (lgtA, -B, -C, -E, -H, and -F) and inner core substituents (lgtG, lpt-3, and lpt-6). For this study, we selected seven strains belonging to subgroup III, a major clonal complex responsible for meningococcal meningitis epidemics in Africa. In addition, we sequenced the homopolymeric tract regions of three phase-variable genes (lgtA, lgtG, and lot-3) to predict gene functionality. The fine structure of the L11 LOS of each strain was determined using composition and glycosyl linkage analyses, NMR, and mass spectrometry. The masses of the dephosphorylated oligosaccharides were consistent with an oligosaccharide composed of two hexoses, one N-acetyl-hexosamine, two heptoses, and one KDO, as proposed previously. The molar composition of LOS showed two glucose residues to be present, in agreement with lgtH sequence prediction. Despite phosphoethanolaminetransferase genes lpt-3 and lpt-6 being present in all seven Neisseria meningitidis strains, phosphoethanolamine (PEtn) was found at both O-3 and O-6 of HepII among the three ST-5 strains, whereas among the four ST-7 strains, only one PEtn was found and located at O-3 of the HepII. The L11 LOS was found to be O-acetylated, as was indicated by the presence of the lot-3 gene being in-frame in all of the seven N. meningitidis strains. To our knowledge, these studies represent the first full genetic and structural characterization of the L11 LOS of N. meningitidis. These investigations also suggest the presence of further regulatory mechanisms affecting LOS structure microheterogeneity in N. meningitidis related to PEtn decoration of the inner core.
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Affiliation(s)
- Noëlle Mistretta
- Sanofi Pasteur, 1541 Avenue Marcel Mérieux, 69280 Marcy l'Etoile, France
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