The Experts below are selected from a list of 345 Experts worldwide ranked by ideXlab platform

Yuriy A. Knirel - One of the best experts on this subject based on the ideXlab platform.

  • the unique Structure of bacterial Polysaccharides immunochemical studies on the o antigen of proteus penneri 4034 85 clinical strain classified into a new o83 proteus serogroup
    International Journal of Biological Macromolecules, 2020
    Co-Authors: Malgorzata Siwinska, Antoni Rozalski, Olga G Ovchinnikova, Alexander S Shashkov, Agnieszka Zablotni, Evgeniya A Levina, Yuriy A. Knirel
    Abstract:

    Abstract The serological classification scheme of the opportunistic Proteus bacilli includes a number of Proteus penneri strains. The tested P. penneri 4034-85 strain turned out to be serologically distinguished in ELISA and Western blotting. The O-Polysaccharide was obtained by mild acid degradation of the lipoPolysaccharide of this strain and studied by sugar and methylation analyses and dephosphorylation along with 1H and 13C NMR spectroscopy, including 2D 1H,1H COSY, TOCSY, ROESY, 1H,13C HSQC, HMBC, and HSQC-TOCSY experiments, The O-Polysaccharide was found to have a linear repeating unit containing glycerol 1-phosphate and two residues each of Gal and GlcNAc. The following O-Polysaccharide Structure was established, which, to our knowledge, is unique among known bacterial Polysaccharide Structures: →4)-β- d -GlcpNAc-(1→3)-α- d -Galp-(1→3)-β- d -GlcpNAc-(1→2)-β- d -Galp-(1→3)-Gro-1-P-(O→.

  • Structure and genetics of the o specific Polysaccharide of escherichia coli o27
    Carbohydrate Research, 2018
    Co-Authors: Andrei V. Perepelov, Sof'ya N. Senchenkova, Alexander S Shashkov, Bin Liu, Tingting Chen, Andrei V Filatov, Jingjie Song, Yuriy A. Knirel
    Abstract:

    Abstract The O-specific Polysaccharide (O-antigen) is a part of the lipoPolysaccharide on the cell surface of Gram-negative bacteria. The O-Polysaccharide was obtained by mild acid hydrolysis of the lipoPolysaccharide of Escherichia coli O27 and studied by sugar analysis and Smith degradation along with 1H and 13C NMR spectroscopy. The following Structure of the branched hexasaccharide repeating unit was established, which is unique among known Structures of bacterial Polysaccharides: Download : Download high-res image (70KB) Download : Download full-size image where GlcA is non-stoichiometrically O-acetylated at position 3 (∼22%) or 4 (∼37%). Functions of genes in the O-antigen gene cluster of E. coli O27 were tentatively assigned by comparison with sequences in the available databases and found to be consistent with the O-Polysaccharide Structure.

  • Structure and gene cluster of a tyvelose-containing O-Polysaccharide of an entomopathogenic bacterium Yersinia entomophaga MH96T related to Yersinia pseudotuberculosis.
    Carbohydrate Research, 2017
    Co-Authors: Olga V. Sizova, Yuriy A. Knirel, Anna N. Kondakova, Rima Z. Shaikhutdinova, Sergey A. Ivanov, Mark R. H. Hurst, A. S. Shashkov, M. E. Platonov, Svetlana V. Dentovskaya
    Abstract:

    Abstract An O-Polysaccharide was isolated from the lipoPolysaccharide of an entomopathogenic bacterium Yersinia entomophaga MH96T by mild acid hydrolysis and studied by 2D NMR spectroscopy. The following Structure of the branched tetrasaccharide repeating unit of the Polysaccharide was established: Download : Download high-res image (52KB) Download : Download full-size image where Tyv indicates 3,6-dideoxy- d -arabino-hexose (tyvelose). The Structure established is consistent with the gene content of the O-antigen gene cluster. The O-Polysaccharide Structure and gene cluster of Y. entomophaga are related to those of some Y. pseudotuberculosis serotypes.

  • Structure and gene cluster of the o antigen of escherichia coli o156 containing a pyruvic acid acetal
    Carbohydrate Research, 2016
    Co-Authors: Zhifeng Duan, Andrei V. Perepelov, Sof'ya N. Senchenkova, Alexander S Shashkov, Yuriy A. Knirel
    Abstract:

    Abstract The lipoPolysaccharide of Escherichia coli O156 was degraded under mild acidic and alkaline conditions and the resulting Polysaccharides were studied by sugar analysis and 1H and 13C NMR spectroscopy. The following Structure of the pentasaccharide repeating unit of the O-Polysaccharide was established: Download : Download high-res image (31KB) Download : Download full-size image where Rpyr indicates R-configurated pyruvic acid acetal. Minor O-acetyl groups also were present and tentatively localized on the Gal residues. The gene cluster for biosynthesis of the O-antigen of E. coli O156 was analyzed and shown to be consistent with the O-Polysaccharide Structure.

  • Structure and gene cluster of the o antigen of escherichia coli o165 containing 5 n acetyl 7 n r 3 hydroxybutanoyl pseudaminic acid
    Glycobiology, 2016
    Co-Authors: Sof'ya N. Senchenkova, Andrei V. Perepelov, Andrej Weintraub, Göran Widmalm, Alexander S Shashkov, Yuanyuan Zhang, Yuriy A. Knirel
    Abstract:

    Upon mild acid degradation of the lipoPolysaccharide of Escherichia coli O165, the O-Polysaccharide chain was cleaved at the glycosidic linkage of 5-N-acetyl-7-N-[(R)-3-hydroxybutanoyl]pseudaminic acid (Pse5Hb7Ac). Analysis of the resulting linear tetrasaccharide and alkali-treated lipoPolysaccharide by (1)H/(13)C 1D and 2D nuclear magnetic resonance spectroscopy enabled elucidation of the following Structure of the O-Polysaccharide: →8)-α-Psep5Hb7Ac-(2 → 6)-β-d-Galp-(1 → 4)-β-d-Glсp-(1 → 3)-α-d-GlсpNAc-(1→. The β-d-Galp-(1 → 4)-β-d-Glсp-(1 → 3)-d-GlсpNAc structural element is also present in the O-Polysaccharide of E. coli O82. The content of the O-antigen gene cluster of E. coli O165 was found to be consistent with the O-Polysaccharide Structure established. Functions of proteins encoded in the gene cluster, including enzymes involved in the Pse5Hb7Ac biosynthesis and glycosyltransferases, were putatively assigned by comparison with sequences in available databases.

Alexander S Shashkov - One of the best experts on this subject based on the ideXlab platform.

  • the unique Structure of bacterial Polysaccharides immunochemical studies on the o antigen of proteus penneri 4034 85 clinical strain classified into a new o83 proteus serogroup
    International Journal of Biological Macromolecules, 2020
    Co-Authors: Malgorzata Siwinska, Antoni Rozalski, Olga G Ovchinnikova, Alexander S Shashkov, Agnieszka Zablotni, Evgeniya A Levina, Yuriy A. Knirel
    Abstract:

    Abstract The serological classification scheme of the opportunistic Proteus bacilli includes a number of Proteus penneri strains. The tested P. penneri 4034-85 strain turned out to be serologically distinguished in ELISA and Western blotting. The O-Polysaccharide was obtained by mild acid degradation of the lipoPolysaccharide of this strain and studied by sugar and methylation analyses and dephosphorylation along with 1H and 13C NMR spectroscopy, including 2D 1H,1H COSY, TOCSY, ROESY, 1H,13C HSQC, HMBC, and HSQC-TOCSY experiments, The O-Polysaccharide was found to have a linear repeating unit containing glycerol 1-phosphate and two residues each of Gal and GlcNAc. The following O-Polysaccharide Structure was established, which, to our knowledge, is unique among known bacterial Polysaccharide Structures: →4)-β- d -GlcpNAc-(1→3)-α- d -Galp-(1→3)-β- d -GlcpNAc-(1→2)-β- d -Galp-(1→3)-Gro-1-P-(O→.

  • acinetobacter baumannii k116 capsular Polysaccharide Structure is a hybrid of the k14 and revised k37 Structures
    Carbohydrate Research, 2019
    Co-Authors: Alexander S Shashkov, Nikolay P Arbatsky, Sarah M Cahill, Amy C Westacott, Anastasiya A Kasimova, Mikhail M Shneider, Anastasiya V Popova, Dmitry A Shagin, Andrey A Shelenkov, Yuliya V Mikhailova
    Abstract:

    The genome of Acinetobacter baumannii clinical isolate, MAR-303, recovered in Russia was sequenced and found to contain a novel gene cluster at the A. baumannii K locus for capsule biosynthesis. The gene cluster, designated KL116, included four genes for glycosyltransferases (Gtrs) and a gene for a Wzy polymerase responsible for joining oligosaccharide K units into the capsular Polysaccharide (CPS). The arrangement of KL116 was a hybrid of previously described A. baumannii gene clusters, with two gtr genes and the wzy gene shared by KL37 and the two other gtr genes found in KL14. The Structure of the K116 CPS was established by sugar analysis and Smith degradation, along with one- and two-dimensional 1H and 13C NMR spectroscopy. The CPS is composed of branched pentasaccharide K units containing only neutral sugars, with three monosaccharides in the main chain and a disaccharide side chain. The K116 unit shares internal sugar linkages with the K14 and K37 units, corresponding to the presence of shared gtr genes in the gene clusters. However, the specific linkage formed by Wzy was discrepant between K116 and the previously reported K37 CPS produced by A. baumannii isolate NIPH146. The K37 Structure was therefore revised in this study, and the corrected Wzy linkage found to be identical to the Wzy linkage in K116. The KL116, KL14 and KL37 gene clusters were found in genomes of a variety of A. baumannii strain backgrounds, indicating their global distribution.

  • Structure and genetics of the o specific Polysaccharide of escherichia coli o27
    Carbohydrate Research, 2018
    Co-Authors: Andrei V. Perepelov, Sof'ya N. Senchenkova, Alexander S Shashkov, Bin Liu, Tingting Chen, Andrei V Filatov, Jingjie Song, Yuriy A. Knirel
    Abstract:

    Abstract The O-specific Polysaccharide (O-antigen) is a part of the lipoPolysaccharide on the cell surface of Gram-negative bacteria. The O-Polysaccharide was obtained by mild acid hydrolysis of the lipoPolysaccharide of Escherichia coli O27 and studied by sugar analysis and Smith degradation along with 1H and 13C NMR spectroscopy. The following Structure of the branched hexasaccharide repeating unit was established, which is unique among known Structures of bacterial Polysaccharides: Download : Download high-res image (70KB) Download : Download full-size image where GlcA is non-stoichiometrically O-acetylated at position 3 (∼22%) or 4 (∼37%). Functions of genes in the O-antigen gene cluster of E. coli O27 were tentatively assigned by comparison with sequences in the available databases and found to be consistent with the O-Polysaccharide Structure.

  • Structure and gene cluster of the o antigen of escherichia coli o156 containing a pyruvic acid acetal
    Carbohydrate Research, 2016
    Co-Authors: Zhifeng Duan, Andrei V. Perepelov, Sof'ya N. Senchenkova, Alexander S Shashkov, Yuriy A. Knirel
    Abstract:

    Abstract The lipoPolysaccharide of Escherichia coli O156 was degraded under mild acidic and alkaline conditions and the resulting Polysaccharides were studied by sugar analysis and 1H and 13C NMR spectroscopy. The following Structure of the pentasaccharide repeating unit of the O-Polysaccharide was established: Download : Download high-res image (31KB) Download : Download full-size image where Rpyr indicates R-configurated pyruvic acid acetal. Minor O-acetyl groups also were present and tentatively localized on the Gal residues. The gene cluster for biosynthesis of the O-antigen of E. coli O156 was analyzed and shown to be consistent with the O-Polysaccharide Structure.

  • Structure and gene cluster of the o antigen of escherichia coli o165 containing 5 n acetyl 7 n r 3 hydroxybutanoyl pseudaminic acid
    Glycobiology, 2016
    Co-Authors: Sof'ya N. Senchenkova, Andrei V. Perepelov, Andrej Weintraub, Göran Widmalm, Alexander S Shashkov, Yuanyuan Zhang, Yuriy A. Knirel
    Abstract:

    Upon mild acid degradation of the lipoPolysaccharide of Escherichia coli O165, the O-Polysaccharide chain was cleaved at the glycosidic linkage of 5-N-acetyl-7-N-[(R)-3-hydroxybutanoyl]pseudaminic acid (Pse5Hb7Ac). Analysis of the resulting linear tetrasaccharide and alkali-treated lipoPolysaccharide by (1)H/(13)C 1D and 2D nuclear magnetic resonance spectroscopy enabled elucidation of the following Structure of the O-Polysaccharide: →8)-α-Psep5Hb7Ac-(2 → 6)-β-d-Galp-(1 → 4)-β-d-Glсp-(1 → 3)-α-d-GlсpNAc-(1→. The β-d-Galp-(1 → 4)-β-d-Glсp-(1 → 3)-d-GlсpNAc structural element is also present in the O-Polysaccharide of E. coli O82. The content of the O-antigen gene cluster of E. coli O165 was found to be consistent with the O-Polysaccharide Structure established. Functions of proteins encoded in the gene cluster, including enzymes involved in the Pse5Hb7Ac biosynthesis and glycosyltransferases, were putatively assigned by comparison with sequences in available databases.

Andrei V. Perepelov - One of the best experts on this subject based on the ideXlab platform.

  • Structure and genetics of the o specific Polysaccharide of escherichia coli o27
    Carbohydrate Research, 2018
    Co-Authors: Andrei V. Perepelov, Sof'ya N. Senchenkova, Alexander S Shashkov, Bin Liu, Tingting Chen, Andrei V Filatov, Jingjie Song, Yuriy A. Knirel
    Abstract:

    Abstract The O-specific Polysaccharide (O-antigen) is a part of the lipoPolysaccharide on the cell surface of Gram-negative bacteria. The O-Polysaccharide was obtained by mild acid hydrolysis of the lipoPolysaccharide of Escherichia coli O27 and studied by sugar analysis and Smith degradation along with 1H and 13C NMR spectroscopy. The following Structure of the branched hexasaccharide repeating unit was established, which is unique among known Structures of bacterial Polysaccharides: Download : Download high-res image (70KB) Download : Download full-size image where GlcA is non-stoichiometrically O-acetylated at position 3 (∼22%) or 4 (∼37%). Functions of genes in the O-antigen gene cluster of E. coli O27 were tentatively assigned by comparison with sequences in the available databases and found to be consistent with the O-Polysaccharide Structure.

  • Structure and gene cluster of the o antigen of escherichia coli o156 containing a pyruvic acid acetal
    Carbohydrate Research, 2016
    Co-Authors: Zhifeng Duan, Andrei V. Perepelov, Sof'ya N. Senchenkova, Alexander S Shashkov, Yuriy A. Knirel
    Abstract:

    Abstract The lipoPolysaccharide of Escherichia coli O156 was degraded under mild acidic and alkaline conditions and the resulting Polysaccharides were studied by sugar analysis and 1H and 13C NMR spectroscopy. The following Structure of the pentasaccharide repeating unit of the O-Polysaccharide was established: Download : Download high-res image (31KB) Download : Download full-size image where Rpyr indicates R-configurated pyruvic acid acetal. Minor O-acetyl groups also were present and tentatively localized on the Gal residues. The gene cluster for biosynthesis of the O-antigen of E. coli O156 was analyzed and shown to be consistent with the O-Polysaccharide Structure.

  • Structure and gene cluster of the o antigen of escherichia coli o165 containing 5 n acetyl 7 n r 3 hydroxybutanoyl pseudaminic acid
    Glycobiology, 2016
    Co-Authors: Sof'ya N. Senchenkova, Andrei V. Perepelov, Andrej Weintraub, Göran Widmalm, Alexander S Shashkov, Yuanyuan Zhang, Yuriy A. Knirel
    Abstract:

    Upon mild acid degradation of the lipoPolysaccharide of Escherichia coli O165, the O-Polysaccharide chain was cleaved at the glycosidic linkage of 5-N-acetyl-7-N-[(R)-3-hydroxybutanoyl]pseudaminic acid (Pse5Hb7Ac). Analysis of the resulting linear tetrasaccharide and alkali-treated lipoPolysaccharide by (1)H/(13)C 1D and 2D nuclear magnetic resonance spectroscopy enabled elucidation of the following Structure of the O-Polysaccharide: →8)-α-Psep5Hb7Ac-(2 → 6)-β-d-Galp-(1 → 4)-β-d-Glсp-(1 → 3)-α-d-GlсpNAc-(1→. The β-d-Galp-(1 → 4)-β-d-Glсp-(1 → 3)-d-GlсpNAc structural element is also present in the O-Polysaccharide of E. coli O82. The content of the O-antigen gene cluster of E. coli O165 was found to be consistent with the O-Polysaccharide Structure established. Functions of proteins encoded in the gene cluster, including enzymes involved in the Pse5Hb7Ac biosynthesis and glycosyltransferases, were putatively assigned by comparison with sequences in available databases.

  • Structure of the O-Polysaccharide of Escherichia coli O132
    Carbohydrate Research, 2016
    Co-Authors: Alexander S Shashkov, Andrei V. Perepelov, Andrej Weintraub, Göran Widmalm, Wenwen Zhang, Bin Liu, Yuriy A. Knirel
    Abstract:

    Mild acid degradation of the lipoPolysaccharide of Escherichia coli O132 released its O-Polysaccharide. Analysis by 1D and 2D (1)H and (13)C NMR spectroscopy prior and subsequent to O-deacetylation, in conjunction with sugar analysis, revealed a linear pentasaccharide repeating unit of the O-Polysaccharide having the following Structure: →2)-α-d-Galf-(1→3)-α-l-Rhap2Ac-(1→4)-α-d-Glcp-(1→2)-α-l-Rhap-(1→3)-β-d-GlcpNAc-(1→ Putative functions of genes in the O-antigen gene cluster of E. coli O132 are consistent with the O-Polysaccharide Structure.

  • Structure and genetics of the o antigen of enterobacter cloacae c6285 containing di n acetyllegionaminic acid
    Carbohydrate Research, 2014
    Co-Authors: Andrei V Filatov, Andrei V. Perepelov, Alexander S Shashkov, Lei Wang, Min Wang, Wenjing Wang, Yuriy A. Knirel
    Abstract:

    Abstract On mild acid degradation of the lipoPolysaccharide of Enterobacter cloacae C6285, the O-Polysaccharide was cleaved at residues of 5,7-diacetamido-3,5,7,9-tetradeoxy- d - glycero - d - galacto -non-2-ulosonic acid (di- N -acetyllegionaminic acid, Leg5Ac7Ac) in the main chain. The resultant oligosaccharide and an alkali-treated lipoPolysaccharide were studied by sugar analysis along with 1 H and 13 C NMR spectroscopy, and the following Structure of the tetrasaccharide repeating unit of the linear O-Polysaccharide was established: →4)-α- d -Gal p -(1→4)-α-Leg p 5Ac7Ac-(2→3)-β- d -Gal p -(1→3)-β- d -Gal p NAc-(1→ The O-antigen gene cluster of E. cloacae C6285 was sequenced, the gene functions were tentatively assigned by comparison with sequences in the available databases and found to be in agreement with the O-Polysaccharide Structure.

Lei Wang - One of the best experts on this subject based on the ideXlab platform.

  • Structure and genetics of the o antigen of enterobacter cloacae c6285 containing di n acetyllegionaminic acid
    Carbohydrate Research, 2014
    Co-Authors: Andrei V Filatov, Andrei V. Perepelov, Alexander S Shashkov, Lei Wang, Min Wang, Wenjing Wang, Yuriy A. Knirel
    Abstract:

    Abstract On mild acid degradation of the lipoPolysaccharide of Enterobacter cloacae C6285, the O-Polysaccharide was cleaved at residues of 5,7-diacetamido-3,5,7,9-tetradeoxy- d - glycero - d - galacto -non-2-ulosonic acid (di- N -acetyllegionaminic acid, Leg5Ac7Ac) in the main chain. The resultant oligosaccharide and an alkali-treated lipoPolysaccharide were studied by sugar analysis along with 1 H and 13 C NMR spectroscopy, and the following Structure of the tetrasaccharide repeating unit of the linear O-Polysaccharide was established: →4)-α- d -Gal p -(1→4)-α-Leg p 5Ac7Ac-(2→3)-β- d -Gal p -(1→3)-β- d -Gal p NAc-(1→ The O-antigen gene cluster of E. cloacae C6285 was sequenced, the gene functions were tentatively assigned by comparison with sequences in the available databases and found to be in agreement with the O-Polysaccharide Structure.

  • Structure elucidation and gene cluster annotation of the o antigen of escherichia coli o39 application of anhydrous trifluoroacetic acid for selective cleavage of glycosidic linkages
    Carbohydrate Research, 2014
    Co-Authors: Andrei V. Perepelov, Alexander S Shashkov, Lei Wang, Andrei V Filatov, Quan Wang, Vyacheslav L Lvov, Ye Qian, Yuriy A. Knirel
    Abstract:

    O-Polysaccharide (O-antigen) accompanied by a minor mannan was isolated from the lipoPolysaccharide of Escherichia coli O39 and studied by component analyses, methylation, Smith degradation, mass spectrometry, and 1D and 2D NMR spectroscopy. In addition, a new approach, solvolysis with anhydrous trifluoroacetic acid, was applied to cleave selectively the rhamnosidic linkage. The following Structure of the O-Polysaccharide was established: α--D-Galpl-->3-->3)-β-D-Quip4N(R3Hb)-(1-->2)-α-D-Manp-(l-->4)-α-L-Rhap-(1-->3)-α-D-GlcpNAc-(1--> where D-Qui4N(R3Hb) indicates 4,6-dideoxy-4-[(R)-3-hydroxybutanoylamino]-d-glucose. The O-antigen gene cluster of E. coli O39 has been sequenced. The gene functions were tentatively assigned by a comparison with sequences in the available databases and found to be in agreement with the O-Polysaccharide Structure.

  • structural serological and genetic characterization of the o antigen of providencia alcalifaciens o40
    Fems Immunology and Medical Microbiology, 2012
    Co-Authors: Antoni Rozalski, Nina A. Kocharova, Olga G Ovchinnikova, Magdalena Bialczakkokot, Alexander S Shashkov, Lu Feng, Lei Wang, Yuriy A. Knirel
    Abstract:

    The O-Polysaccharide chain of the lipoPolysaccharide (O-antigen) on the bacterial cell surface is one of the most structurally variable cell components and serves as a basis for serotyping of Gram-negative bacteria, including human opportunistic pathogens of the genus Providencia . In this work, the O-antigen of Providencia alcalifaciens O40 was obtained by mild acid degradation of the isolated lipoPolysaccharide and studied by chemical methods and high-resolution NMR spectroscopy. The following Structure of the O-Polysaccharide was established: →4)-β-d-Qui p 3NFo-(1→3)-α-d-Gal p -(1→3)-β-d-Glc p A-(1→3)-β-d-Gal p NAc-(1→, where GlcA stands for glucuronic acid and Qui3NFo for 3,6-dideoxy-3-formamidoglucose. The O40-antigen was found to be structurally and serologically related to the O-antigens of P. alcalifaciens O5 and Providencia stuartii O18. The O40-antigen gene cluster between cpxA and yibK was sequenced, and the gene functions were predicted in silico . In agreement with the O-Polysaccharide Structure established, the genes for the synthesis of dTDP-d-Qui3NFo, UDP-d-Gal, UDP-d-GlcA, and UDP-d-GalNAc as well as those encoding three glycosyltransferases, flippase (Wzx), and O-antigen polymerase (Wzy) were recognized. In addition, homologues of wza, wzb , and wzc genes, which are required for the surface expression of capsular Polysaccharides, were found within the gene cluster, suggesting that the O-Polysaccharide studied is a part of the capsule-related form of the lipoPolysaccharide called KLPS.

  • Structure and genetics of the o antigen of cronobacter sakazakii g2726 serotype o3 closely related to the o antigen of c muytjensii 3270
    Carbohydrate Research, 2012
    Co-Authors: Nikolay P Arbatsky, Alexander S Shashkov, Lei Wang, Bin Liu, Yamin Sun, Min Wang, Elena D Daeva, Yuriy A. Knirel
    Abstract:

    Abstract The O-specific Polysaccharide (O-antigen) was isolated from the lipoPolysaccharide of Cronobacter sakazakii G2726 (serotype O3) and studied by sugar analysis, Smith degradation, and 1 H and 13 C NMR spectroscopy. The following Structure of the acidic O-Polysaccharide was established: Download full-size image This Structure is closely related to that of the O-Polysaccharide of Cronobacter muytjensii 3270, which has the same main chain and differs only in the lack of glucosylation. The O-antigen gene cluster of C. sakazakii G2726 found between the gnd and galF genes was sequenced, and the gene functions were tentatively assigned by similarity to related genes from available databases and taking into account the O-Polysaccharide Structure.

  • Structure of o antigen and functional characterization of o antigen gene cluster of salmonella enterica o47 containing ribitol phosphate and 2 acetimidoylamino 2 6 dideoxy l galactose
    Biochemistry, 2009
    Co-Authors: Andrei V. Perepelov, Sof'ya N. Senchenkova, Lu Feng, Lei Wang, A. S. Shashkov, Bin Liu, Yuriy A. Knirel
    Abstract:

    An O-Polysaccharide was isolated by mild acid degradation of the lipoPolysaccharide of Salmonella enterica O47 and studied by sugar analysis along with one- and two-dimensional 1H- and 13C-NMR spectroscopy. The following Structure of the linear ribitol phosphate-containing repeating unit of the O-Polysaccharide was established: \( \to 2) - D - Ribitol - 5 - P - (O \to 6) - \alpha - D - Galp - (1 \to 3) - \alpha - L - FucpNAm - (1 \to 3) - \beta - D - GlcpNAc - (1 \to , \) where FucNAm stands for 2-acetimidoylamino-2,6-dideoxy-L-galactose. About 10% of Gal is O-acetylated at position 4 and another minor O-acetyl group is present at an undetermined position. Functions of the S. enterica O47 antigen biosynthetic genes were tentatively assigned by comparison with gene databases and found to be in agreement with the O-Polysaccharide Structure. A comparison of the O-antigen gene clusters of S. enterica O47 and E. coli O145 suggested their close evolutionary relationship.

Sof'ya N. Senchenkova - One of the best experts on this subject based on the ideXlab platform.

  • Structure and genetics of the o specific Polysaccharide of escherichia coli o27
    Carbohydrate Research, 2018
    Co-Authors: Andrei V. Perepelov, Sof'ya N. Senchenkova, Alexander S Shashkov, Bin Liu, Tingting Chen, Andrei V Filatov, Jingjie Song, Yuriy A. Knirel
    Abstract:

    Abstract The O-specific Polysaccharide (O-antigen) is a part of the lipoPolysaccharide on the cell surface of Gram-negative bacteria. The O-Polysaccharide was obtained by mild acid hydrolysis of the lipoPolysaccharide of Escherichia coli O27 and studied by sugar analysis and Smith degradation along with 1H and 13C NMR spectroscopy. The following Structure of the branched hexasaccharide repeating unit was established, which is unique among known Structures of bacterial Polysaccharides: Download : Download high-res image (70KB) Download : Download full-size image where GlcA is non-stoichiometrically O-acetylated at position 3 (∼22%) or 4 (∼37%). Functions of genes in the O-antigen gene cluster of E. coli O27 were tentatively assigned by comparison with sequences in the available databases and found to be consistent with the O-Polysaccharide Structure.

  • Structure and gene cluster of the o antigen of escherichia coli o156 containing a pyruvic acid acetal
    Carbohydrate Research, 2016
    Co-Authors: Zhifeng Duan, Andrei V. Perepelov, Sof'ya N. Senchenkova, Alexander S Shashkov, Yuriy A. Knirel
    Abstract:

    Abstract The lipoPolysaccharide of Escherichia coli O156 was degraded under mild acidic and alkaline conditions and the resulting Polysaccharides were studied by sugar analysis and 1H and 13C NMR spectroscopy. The following Structure of the pentasaccharide repeating unit of the O-Polysaccharide was established: Download : Download high-res image (31KB) Download : Download full-size image where Rpyr indicates R-configurated pyruvic acid acetal. Minor O-acetyl groups also were present and tentatively localized on the Gal residues. The gene cluster for biosynthesis of the O-antigen of E. coli O156 was analyzed and shown to be consistent with the O-Polysaccharide Structure.

  • Structure and gene cluster of the o antigen of escherichia coli o165 containing 5 n acetyl 7 n r 3 hydroxybutanoyl pseudaminic acid
    Glycobiology, 2016
    Co-Authors: Sof'ya N. Senchenkova, Andrei V. Perepelov, Andrej Weintraub, Göran Widmalm, Alexander S Shashkov, Yuanyuan Zhang, Yuriy A. Knirel
    Abstract:

    Upon mild acid degradation of the lipoPolysaccharide of Escherichia coli O165, the O-Polysaccharide chain was cleaved at the glycosidic linkage of 5-N-acetyl-7-N-[(R)-3-hydroxybutanoyl]pseudaminic acid (Pse5Hb7Ac). Analysis of the resulting linear tetrasaccharide and alkali-treated lipoPolysaccharide by (1)H/(13)C 1D and 2D nuclear magnetic resonance spectroscopy enabled elucidation of the following Structure of the O-Polysaccharide: →8)-α-Psep5Hb7Ac-(2 → 6)-β-d-Galp-(1 → 4)-β-d-Glсp-(1 → 3)-α-d-GlсpNAc-(1→. The β-d-Galp-(1 → 4)-β-d-Glсp-(1 → 3)-d-GlсpNAc structural element is also present in the O-Polysaccharide of E. coli O82. The content of the O-antigen gene cluster of E. coli O165 was found to be consistent with the O-Polysaccharide Structure established. Functions of proteins encoded in the gene cluster, including enzymes involved in the Pse5Hb7Ac biosynthesis and glycosyltransferases, were putatively assigned by comparison with sequences in available databases.

  • Structure of o antigen and functional characterization of o antigen gene cluster of salmonella enterica o47 containing ribitol phosphate and 2 acetimidoylamino 2 6 dideoxy l galactose
    Biochemistry, 2009
    Co-Authors: Andrei V. Perepelov, Sof'ya N. Senchenkova, Lu Feng, Lei Wang, A. S. Shashkov, Bin Liu, Yuriy A. Knirel
    Abstract:

    An O-Polysaccharide was isolated by mild acid degradation of the lipoPolysaccharide of Salmonella enterica O47 and studied by sugar analysis along with one- and two-dimensional 1H- and 13C-NMR spectroscopy. The following Structure of the linear ribitol phosphate-containing repeating unit of the O-Polysaccharide was established: \( \to 2) - D - Ribitol - 5 - P - (O \to 6) - \alpha - D - Galp - (1 \to 3) - \alpha - L - FucpNAm - (1 \to 3) - \beta - D - GlcpNAc - (1 \to , \) where FucNAm stands for 2-acetimidoylamino-2,6-dideoxy-L-galactose. About 10% of Gal is O-acetylated at position 4 and another minor O-acetyl group is present at an undetermined position. Functions of the S. enterica O47 antigen biosynthetic genes were tentatively assigned by comparison with gene databases and found to be in agreement with the O-Polysaccharide Structure. A comparison of the O-antigen gene clusters of S. enterica O47 and E. coli O145 suggested their close evolutionary relationship.

  • the o Polysaccharide of escherichia coli o112ac has the same Structure as that of shigella dysenteriae type 2 but is devoid of o acetylation a revision of the s dysenteriae type 2 o Polysaccharide Structure
    Carbohydrate Research, 2008
    Co-Authors: Andrei V. Perepelov, Andrej Weintraub, Göran Widmalm, Sof'ya N. Senchenkova, Alexander S Shashkov, Lu Feng, Lei Wang, Yuriy A. Knirel
    Abstract:

    Abstract The O-antigen Structure of Shigella dysenteriae type 2 was reinvestigated using chemical modifications along with high-resolution 2D 1 H and 13 C NMR spectroscopy. The O-antigen was found to contain a pyruvic acid acetal, which was overlooked in an early study, and the following revised Structure of the pentasaccharide repeating unit was established: Download full-size image where ∼70% GlcNAc residues bear an O -acetyl group at position 3. The O-antigen of Escherichia coli O112ac was found to have the same carbohydrate Structure but to lack O-acetylation.