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Erik D Cram, Daniel D Rockey, Brian P Dolan
BACKGROUND: Chlamydia species are obligate intracellular bacteria that infect a broad range of mammalian hosts. Members of related genera are pathogens of a variety of vertebrate and invertebrate species. Despite the diversity of Chlamydia, all species contain an outer membrane lipooligosaccharide (LOS) that is comprised of a genus-conserved, and genus-defining, trisaccharide 3-deoxy-D-manno-oct-2-ulosonic acid Kdo region. Recent studies with lipopolysaccharide inhibitors demonstrate that LOS is important for the C...
April 24, 2017: BMC Microbiology
Javier Salazar, Mackarenna Alarcón, Jaime Huerta, Belén Navarro, Daniel Aguayo
Phosphoethanolamine (pEtN) decoration of E. coli Lipopolysaccharide (LPS) provides resistance to the antimicrobial Polymyxin B (PolB). While EptA and EptB enzymes catalyze the addition of pEtN to the Lipid A and Kdo (pEtN-Kdo-Lipid A), EptC catalyzes the pEtN addition to the Heptose I (pEtN-HeptI). In this study, we investigated the contribution of pEtN-HeptI to PolB resistance using eptA/eptB and eptC deficient E. coli K12 and its wild-type parent strains. These mutations were shown to decrease the antimicrobial activity of PolB on cells grown under pEtN-addition inducing conditions...
April 15, 2017: Archives of Biochemistry and Biophysics
Taylor Chance, Jennifer Chua, Ronald G Toothman, Jason T Ladner, Jonathan E Nuss, Jo Lynne Raymond, Fabrice V Biot, Samandra Demons, Lynda Miller, Stephanie Halasohoris, Sherry Mou, Galina Koroleva, Sean Lovett, Gustavo Palacios, Nicholas J Vietri, Patricia L Worsham, Christopher K Cote, Todd M Kijek, Joel A Bozue
Francisella tularensis, a gram-negative facultative intracellular bacterial pathogen, is the causative agent of tularemia and able to infect many mammalian species, including humans. Because of its ability to cause a lethal infection, low infectious dose, and aerosolizable nature, F. tularensis subspecies tularensis is considered a potential biowarfare agent. Due to its in vitro efficacy, ciprofloxacin is one of the antibiotics recommended for post-exposure prophylaxis of tularemia. In order to identify therapeutics that will be efficacious against infections caused by drug resistant select-agents and to better understand the threat, we sought to characterize an existing ciprofloxacin resistant (CipR) mutant in the Schu S4 strain of F...
2017: PloS One
Hong Li, Tiandi Yang, Tingting Liao, Aleksandra W Debowski, Hans-Olof Nilsson, Alma Fulurija, Stuart M Haslam, Barbara Mulloy, Anne Dell, Keith A Stubbs, Barry J Marshall, Mohammed Benghezal
Helicobacter pylori lipopolysaccharide promotes chronic gastric colonisation through O-antigen host mimicry and resistance to mucosal antimicrobial peptides mediated primarily by modifications of the lipid A. The structural organisation of the core and O-antigen domains of H. pylori lipopolysaccharide remains unclear, as the O-antigen attachment site has still to be identified experimentally. Here, structural investigations of lipopolysaccharides purified from two wild-type strains and the O-antigen ligase mutant revealed that the H...
March 2017: PLoS Pathogens
Danielle M Williams, Olga G Ovchinnikova, Akihiko Koizumi, Iain L Mainprize, Matthew S Kimber, Todd L Lowary, Chris Whitfield
Lipopolysaccharides (LPS) are essential outer membrane glycolipids in most gram-negative bacteria. Biosynthesis of the O-antigenic polysaccharide (OPS) component of LPS follows one of three widely distributed strategies, and similar processes are used to assemble other bacterial surface glycoconjugates. This study focuses on the ATP-binding cassette (ABC) transporter-dependent pathway, where glycans are completed on undecaprenyl diphosphate carriers at the cytosol:membrane interface, before export by the ABC transporter...
February 14, 2017: Proceedings of the National Academy of Sciences of the United States of America
Carol L Ladner-Keay, Marcia LeVatte, David S Wishart
Conversion of native cellular prion protein (PrP(c)) from an α-helical structure to a toxic and infectious β-sheet structure (PrP(Sc)) is a critical step in the development of prion disease. There are some indications that the formation of PrP(Sc) is preceded by a β-sheet rich PrP (PrP(β)) form which is non-infectious, but is an intermediate in the formation of infectious PrP(Sc). Furthermore the presence of lipid cofactors is thought to be critical in the formation of both intermediate-PrP(β) and lethal, infectious PrP(Sc)...
November 2016: Prion
Hye-Ryung Park, Su Beom Park, Hee-Do Hong, Hyung Joo Suh, Kwang-Soon Shin
The aim of this study was to characterize a polysaccharide found in citrus peels with an anti-metastatic property. CPE-II was purified by the pectinase digestion of citrus peels. During in vivo lung metastasis of Colon26-M3.1, administration of 10μg of CPE-II per mouse showed 81.3% inhibition of metastasis. CPE-II consists of 15 different monosaccharides and 22 different glycosyl linkages, characteristic of rhamnogalacturonan II (RG-II). The primary structure was elucidated based on sugar composition, methylation analysis, oligosaccharide analysis, and sequencing using GC, GC-MS, LC-MS, and ESI-MS/MS analyses...
January 2017: International Journal of Biological Macromolecules
Marcelina Mazur, Barbara Barycza, Hanitra Andriamboavonjy, Serge Lavoie, Marielle Tamigney Kenfack, Anaïs Laroussarie, Yves Blériot, Charles Gauthier
3-Deoxy-β-d-manno-oct-2-ulosonic acid (β-Kdo) glycosides are mainly found in capsular polysaccharides and extracellular exopolysaccharides from Gram-negative bacteria. These compounds have profound biological implications in immune response and act as virulence factors. We have developed a novel methodology for the stereoselective synthesis of β-Kdo glycosides via the use of a 4'-methoxyphenacyl (Phen) auxiliary group at the C1 position of a peracetylated β-Kdo thioglycoside. Under the promotion of NIS/AgOTf in acetonitrile, a series of Kdo glycosides was synthesized in good yield and β-selectivity while minimizing the formation of undesirable glycals...
November 18, 2016: Journal of Organic Chemistry
Tim Steffens, Katarzyna Duda, Buko Lindner, Frank-Jörg Vorhölter, Hanna Bednarz, Karsten Niehaus, Otto Holst
Xanthomonas translucens pv. translucens (Xtt) is a Gram-negative pathogen of crops from the plant family Poaceae The lipopolysaccharide (LPS) of Xtt was isolated and chemically characterized. The analyses revealed the presence of rhamnose, xylose, mannose, glucose, galacturonic acid, phosphates, 3-deoxy-D-manno-oct-2-ulopyranosonic acid (Kdo) and fatty acids (10:0, 11:0, 11:0(3-OH) i/a, 11:0(3-OH), 12:0(3-OH) i/a, 12:0(3-OH), 12:0, 13:0(3-OH) i, 13:0(3-OH) a, 13:0(3-OH), 14:0(3-OH) i/a, 14:0(3-OH) and 16:0)...
September 9, 2016: Glycobiology
Maxim S Kokoulin, Alexandra S Kuzmich, Anatoly I Kalinovsky, Svetlana V Tomshich, Lyudmila A Romanenko, Valery V Mikhailov, Nadezhda A Komandrova
We presented the structure of the polysaccharide moiety and anticancer activity in vitro of the sulfated lipopolysaccharide isolated from the marine bacterium Cobetia litoralis KMM 3880(T). The structure of O-polysaccharide was investigated by chemical methods along with (1)H and (13)C NMR spectroscopy. The O-polysaccharide was built up of branched trisaccharide repeating units consist of D-glucose (D-Glcр), D-mannose (D-Manр) and sulfated 3-deoxy-d-manno-oct-2-ulosonic acid (Kdo5S): →7-β-Kdoр4Ac5S-(2→4)-[β-d-Glcp-(1→2)-]-β-d-Manр6Ac-1→...
December 10, 2016: Carbohydrate Polymers
Masahito Hashimoto, Mami Ozono, Maiko Furuyashiki, Risako Baba, Shuhei Hashiguchi, Yasuo Suda, Koichi Fukase, Yukari Fujimoto
Acetobacter pasteurianus is an aerobic Gram-negative rod that is used in the fermentation process used to produce the traditional Japanese black rice vinegar kurozu. Previously, we found that a hydrophobic fraction derived from kurozu stimulates Toll-like receptors to produce cytokines. LPSs, particularly LPS from A. pasteurianus, are strong candidates for the immunostimulatory component of kurozu. The LPS of A. pasteurianus remains stable in acidic conditions during the 2 years of the abovementioned fermentation process...
September 30, 2016: Journal of Biological Chemistry
Olga G Ovchinnikova, Liam Doyle, Bo-Shun Huang, Matthew S Kimber, Todd L Lowary, Chris Whitfield
3-Deoxy-d-manno-oct-2-ulosonic acid (Kdo) is an essential component of bacterial lipopolysaccharides, where it provides the linkage between lipid and carbohydrate moieties. In all known LPS structures, Kdo residues possess α-anomeric configurations, and the corresponding inverting α-Kdo transferases are well characterized. Recently, it has been shown that a large group of capsular polysaccharides from Gram-negative bacteria, produced by ATP-binding cassette transporter-dependent pathways, are also attached to a lipid anchor through a conserved Kdo oligosaccharide...
October 7, 2016: Journal of Biological Chemistry
Abdellatif Tikad, Huixiao Fu, Charlotte M Sevrain, Sophie Laurent, Jean-François Nierengarten, Stéphane P Vincent
The synthesis of unprecedented multimeric Kdo glycoclusters based on fullerene and calix[4]arene central scaffolds is reported. The compounds were used to study the mechanism and scope of multivalent glycosyltransferase inhibition. Multimeric mannosides based on porphyrin and pillar[5]arenes were also generated in a controlled manner. Twelve glycoclusters and their monomeric ligands were thus assayed against heptosyltransferase WaaC, which is an important bacterial glycosyltransferase that is involved in lipopolysaccharide biosynthesis...
September 5, 2016: Chemistry: a European Journal
Jason H Barker, Justin W Kaufman, Michael A Apicella, Jerrold P Weiss
Francisella tularensis, the Gram-negative bacterium that causes tularemia, produces a high molecular weight capsule that is immunologically distinct from Francisella lipopolysaccharide but contains the same O-antigen tetrasaccharide. To pursue the possibility that the capsule of Francisella live vaccine strain (LVS) has a structurally unique lipid anchor, we have metabolically labeled Francisella with [14C]acetate to facilitate highly sensitive compositional analysis of capsule-associated lipids. Capsule was purified by two independent methods and yielded similar results...
2016: PloS One
Barbara Pokorny, Paul Kosma
The ketosidic linkage of 3-deoxy-d-manno-octulosonic acid (Kdo) to lipid A constitutes a general structural feature of the bacterial lipopolysaccharide core. Glycosylation reactions of Kdo donors, however, are challenging due to the absence of a directing group at C-3 and elimination reactions resulting in low yields and anomeric selectivities of the glycosides. While 3-iodo-Kdo fluoride donors showed excellent glycosyl donor properties for the assembly of Kdo oligomers, glycosylation of N-acetyl-glucosamine derivatives was not straightforward...
December 2015: ChemistryOpen
Paul Kosma
Glycosylation chemistry of 3-deoxy-D-manno-oct-2-ulosonic acid units has been considerably developed within the last decade. This review covers major achievements with respect to improved yields and anomeric selectivity as well as suppression of the elimination side reaction via selection of dedicated protecting groups and appropriate activation of the anomeric center.
May 18, 2016: Tetrahedron Letters
Olga G Ovchinnikova, Evan Mallette, Akihiko Koizumi, Todd L Lowary, Matthew S Kimber, Chris Whitfield
Kdo (3-deoxy-d-manno-oct-2-ulosonic acid) is an eight-carbon sugar mostly confined to Gram-negative bacteria. It is often involved in attaching surface polysaccharides to their lipid anchors. α-Kdo provides a bridge between lipid A and the core oligosaccharide in all bacterial LPSs, whereas an oligosaccharide of β-Kdo residues links "group 2" capsular polysaccharides to (lyso)phosphatidylglycerol. β-Kdo is also found in a small number of other bacterial polysaccharides. The structure and function of the prototypical cytidine monophosphate-Kdo-dependent α-Kdo glycosyltransferase from LPS assembly is well characterized...
May 31, 2016: Proceedings of the National Academy of Sciences of the United States of America
Liuqing Wen, Yuan Zheng, Tiehai Li, Peng George Wang
The studies of 3-deoxy-d-manno-octulosonic acid (KDO) have been hindered due to its limited availability. Herein, an efficient enzymatic system for the facile synthesis of KDO from easy-to-get starting materials is described. In this one-pot three-enzyme (OPME) system, d-ribulose 5-phosphate, which was prepared from d-xylose, was employed as starting materials. The reaction process involves the isomerization of d-ribulose 5-phosphate to d-arabinose 5-phosphate catalyzed by d-arabinose 5-phosphate isomerase (KdsD), the aldol condensation of d-arabinose 5-phosphate and phosphoenolpyruvate (PEP) catalyzed by KDO 8-phosphate synthetase (KdsA), and the hydrolysis of KDO-8-phosphate catalyzed by KDO 8-phosphate phosphatase (KdsC)...
June 15, 2016: Bioorganic & Medicinal Chemistry Letters
Aleksandra Man-Kupisinska, Ewelina Bobko, Tomasz K Gozdziewicz, Anna Maciejewska, Wojciech Jachymek, Czeslaw Lugowski, Jolanta Lukasiewicz
Lipopolysaccharide (LPS, endotoxin) is a main surface antigen and virulence factor of Gram-negative bacteria. Regardless of the source of LPS, this molecule, isolated from the smooth forms of bacteria, is characterised by a general structural layout encompassing three regions: (i) an O-specific polysaccharide (O-PS) - a polymer of repeating oligosaccharide units, (ii) core oligosaccharide (OS), and (iii) the lipid A anchoring LPS in the outer membrane of the cell envelope of Gram-negative bacteria. Structural analysis usually requires degradation of LPS and further efficient separation of various poly- and oligosaccharide glycoforms...
June 2, 2016: Carbohydrate Research
Kimberly F Starr, Eric A Porsch, Patrick C Seed, Joseph W St Geme
Kingella kingae is a common cause of invasive disease in young children and was recently found to produce a polysaccharide capsule containing N-acetylgalactosamine (GalNAc) and β-3-deoxy-d-manno-octulosonic acid (βKdo). Given the role of capsules as important virulence factors and effective vaccine antigens, we set out to determine the genetic determinants of K. kingae encapsulation. Using a transposon library and a screen for nonencapsulated mutants, we identified the previously identified ctrABCD (ABC transporter) operon, a lipA (kpsC)-like gene, a lipB (kpsS)-like gene, and a putative glycosyltransferase gene designated csaA (capsule synthesis type a gene A)...
June 2016: Infection and Immunity
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