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A S Shashkov

Publications and source records attributed to A S Shashkov.

At least 109 records · Page 6Linked to original sources
PubMed1998

Structure of a new neutral O-specific polysaccharide of Proteus penneri 34.

The O-specific polysaccharide of Proteus penneri strain 34 was studied using 1H and 13C NMR spectroscopy, including 2D COSY, TOCSY, NOESY, and H-detected 1H, 13C HMQC experiments. The following structure was established, which is unique among the known structures of Proteus O-antigens:-->4)-beta-D-Glcp-(1-->3)-beta-D-GalpNAc-(1-->4)-beta- D-GalpNAc-(1-->4)-beta-D-Galp-(1-->. Accordingly, no cross-reaction was observed between P. penneri 34 O-antiserum and O-antigens of other Proteus strains. Therefore, the strain studied should belong to a new Proteus serogroup O65.

Animals↗
PubMed1998

Structure of the O-specific polysaccharide of Proteus penneri strain 41 from a new proposed serogroup O62.

O-specific polysaccharide of Proteus penneri strain 41 was studied using 1H- and 13C-NMR spectroscopy, including two-dimensional COSY, heteronuclear 13C,1H-correlation (HETCOR) and one-dimensional NOE spectroscopy, and the following structure of a non-stoichiometrically O-acetylated hexasaccharide repeating unit was established:[structure: see text] where RGlcNAc is 2-acetamido-4-O-[(S)-1-carboxyethyl]-2-deoxyglucose. Cross-reactivity of anti-P. penneri 41 O-serum with other P. penneri strains is discussed, and a new, separate O62 serogroup is proposed which is the next Proteus O-serogroup containing P. penneri strains only.

Animals↗
PubMed1998

Immunochemical studies on R mutants of Yersinia enterocolitica O:3.

Three mutants of Yersinia enterocolitica O:3, namely: YeO3-R1, YeO3-RfbR7 and YeO3-c-trs8-R were classified on the basis of sodium dodecyl sulphate/polyacrylamide gel electrophoresis (SDS/PAGE) profile of isolated lipopolysaccharides (LPS) as belonging to the Ra- (the first) and the Rc-type (the other two mutants). Methylation analysis, in addition to 13C and 1H NMR studies of purified core oligosaccharides revealed structures similar to those established previously for the full core of Y. enterocolitica O:3 in the case of the Ra mutant, and identical to that reported for the Rc mutant Ye75R, in the case of the two other mutants. The O-specific sugar, 6d-L-altrose, which forms a homopolymeric O-chain, was present in small amounts in all three LPS preparations, as well as in the core oligosaccha ride preparations along with the Ra and the Rc sugars, characteristic of the Y. enterocolitica O:3 core. This result is in line with genetic data, indicating that it is the inner core region which is the receptor for the O-specific chain in Y. enterocolitica O:3. This region seems likewise to be the anchoring region for the enterobacterial common antigen (ECA), as shown by SDS/PAGE/Western blot analysis with monoclonal antibodies against ECA. In addition, we also demonstrated that the Ye75R mutant Rc and its parental strain Ye75S, both were ECA-immunogenic strains. So far, ECA-immunogenic strains, i.e. those with LPS-linked ECA, were only identified in E. coli mutants of the R1, R4 and K-12 serotype.

Blotting, Western↗
PubMed1998

Teichoic acids of the cell wall of Nocardiopsis listeri, Nocardiopsis lucentensis, and Nocardiopsis tregalosei.

The structures of teichoic acids of three Nocardiopsis species were established. The cell wall of Nocardiopsis listeri VKM Ac-1881T contains two teichoic acids (TA). TA1 is 1,3-poly(glycerol phosphate) with 50% glycerol phosphate residues substituted by alpha-N-acetylglucosamine in the C-2 position. TA2 is 1, 5-poly(ribitol phosphate) with each ribitol phosphate unit carrying pyruvate acetal groups in the 2 and 4 positions. The cell wall of Nocardiopsis lucentensis VKM Ac-1963T contains only one teichoic acid of the same structure as TA1 of N. listeri. The teichoic acid of the Nocardiopsis tregalosei VKM Ac-942 is a 1,3-poly(glycerol phosphate) substituted (60%) by beta-glucopyranosyl residues. Structures of polymers were studied by chemical and NMR spectroscopy methods. The presented results confirm the species-specificity of teichoic acids from Nocardiopsis genus.

Actinomycetales↗
PubMed1998

[Synthesis of oligosaccharides related to HNK-1 antigen. 2. Synthesis of 3'''-O-(3-O-sulfo-beta-D-glucuronopyranosyl)-lacto-N-neotetrao se beta-propylglycoside].

A derivative of allyl 3"-O-(2-acetamido-2-deoxy-beta-D-glucopyranosyl)-beta-lactoside with a free OH group at C-4GlcNAc was glycosylated with trichloroacetimidate of selectively protected GlcA(beta 1-->3)Gal alpha disaccharide in dichloromethane in the presence of trimethylsilyl triflate resulting in a pentasaccharide product with an 82% yield. This product was converted to monohydroxy derivative with a free OH group at C-3GlcA via the formation and the subsequent opening of the 6,3-lactone ring in the glucuronic acid residue. The 3"'-O-sulfation of the monohydroxy derivative, the removal of the protective groups, and the reduction of the allyl aglycon yielded the pentasaccharide propyl glycoside NaSO3-3GlcA(beta 1-->3)Gal(beta 1-->4)GlcNAc(beta 1-->3)Gal(beta 1-->4)Glc beta-Opr comprising the oligosaccharide chain of the SGGL-1 glycolipid, which is recognized by HNK-1 antibodies. NaSO3-3GlcA(beta 1--> 3)Gal beta OAll, GlcA(beta 1-->3)Gal(beta 1-->4)GlcNAc(beta 1-->3)Gal(beta 1-->4)Glc beta-OPr and GlcA(beta 1-->3)Gal beta OAll were synthesized in a similar way.

CD57 Antigens↗
PubMed1998

Structure of teichoic acid of the cell wall of Streptomyces sparsogenes VKM Ac-1744T.

The cell wall of Streptomyces sparsogenes VKM Ac-1744T contains a teichoic acid of 1,3-poly(glycerol phosphate) type. The polymer is composed of about 11 repeating units of the following structure: The structure was not identified in gram-positive bacteria previously. The data are in agreement with DNA-relatedness between Streptomyces sparsogenes and Streptomyces hygroscopicus species and suggest the species-specificity of teichoic acid structure in the studied streptomycetes group.

Carbohydrate Sequence↗
PubMed1997

Structure of a phosphorylated polysaccharide from Shewanella putrefaciens strain S29.

A phosphorylated polysaccharide was isolated from the aqueous layer of the phenol-water extract of a non-halophilic bacterium Shewanella putrefaciens strain S29. The glycosyl phosphate linkage in the polysaccharide was split under mild acid conditions to give, after borohydride reduction, a phosphorylated oligosaccharide-alditol. On the basis of sugar analysis and 1H, 13C and 31P NMR spectroscopy, including 2D COSY, relayed COSY, rotating-frame NOE spectroscopy (ROESY), heteronuclear 13C,1H COSY, and H-detected heteronuclear 1H,31P multiple-quantum coherence (HMQC), it was concluded that the polysaccharide is built up of tetrasaccharide-phosphate repeating units having the following structure: [sequence: see text] where QuiNAc and Qui4NAc are 2-acetamido-2,6-dideoxyglucose and 4-acetamido-4,6-dideoxyglucose, respectively.

Carbohydrate Sequence↗
PubMed1997

Structure of a sulfated xylogalactan from the calcareous red alga Corallina pilulifera P. et R. (Rhodophyta, Corallinaceae).

The structure of a sulfated polysaccharide isolated from the calcareous red alga Corallina pilulifera was studied by methylation analysis before and after desulfation or Smith degradation, as well as by 1D and 2D 1H and 13C NMR spectroscopy. The polysaccharide was shown to consist of D-galactose, L-galactose, 2-O-methyl-L-galactose, 3-O-methyl-L-galactose, 6-O-methyl-D-galactose, D-xylose, and sulfate in a molar ratio of 29:20:5:2:1:20:23. Its agaran-like backbone built up of alternating 3-linked beta-D-galactopyranose and 4-linked alpha-L-galactopyranose residues bears single beta-D-xylopyranosyl substituents at position 6 of beta-D-galactose residues, whereas sulfate and O-methyl groups occupy positions 2 and 3 of alpha-L-galactose and position 6 of beta-D-galactose residues.

Carbohydrate Sequence↗
PubMed1997

Structure of the O-specific polysaccharide of Proteus vulgaris O25 containing 3-O-[(R)-1-carboxyethyl]-D-glucose.

The O-specific polysaccharide of Proteus vulgaris O25 was studied by acid hydrolysis and by 1H-NMR and 13C-NMR spectroscopies, including one-dimensional NOE and two-dimensional COSY and heteronuclear 13C,1H correlation (HETCOR) spectroscopy. The polysaccharide was found to contain 3-O-[(R)-1-carboxyethyl]-D-glucose (D-RGlc), and the following structure of the pentasaccharide repeating unit was established: [structure in text]

Carbohydrate Conformation↗
PubMed1997

Structures of the O-antigens of Proteus bacilli belonging to OX group (serogroups O1-O3) used in Weil-Felix test.

Structures of the O-specific polysaccharide chains of lipopolysaccharides from Proteus group OX strains (serogroups O1-O3) used as antigens in Weil-Felix test for diagnosis of rickettsiosis, were established. From them, the acid-labile polysaccharide of Proteus vulgaris OX19 (O1) is built up of the following branched pentasaccharide repeating units connected via a phosphate group: [structure in text] where QuiNAc stands for 2-acetamido-2,6-dideoxyglucose (N-acetylquinovosamine). The basis of serospecificity of the Proteus group OX antigens and their cross-reactivity with human anti-rickettsial antibodies is discussed.

Antibodies, Bacterial↗
PubMed1997

Structure of the O-specific polysaccharide of Salmonella enterica ssp. arizonae O50 (Arizona 9a,9b).

On the basis of sugar and methylation analysis, selective removal of 3,6-dideoxy-L-xylohexose (colitose, Col), 1H and 13C NMR spectroscopy, including 1D NOE, 2D COSY, and 2D H-detected 1H, 13C heteronuclear multiple-quantum coherence (HMQC), the following structure of the repeating unit of the O-specific polysaccharide of Salmonella enterica ssp. arizonae O50 (Arizona 9a,9b) was established: [sequence: see text] The O-antigen studied includes a trisaccharide fragment alpha-Co1p-(1-->2)-beta-D-Galp-(1-->3)-beta-D-GlcpNAc, which is a colitose ('3-deoxy-L-fucose') analogue of the Lewis (precursor) blood group antigen.

Carbohydrate Conformation↗
PubMed1997

The O-specific polysaccharide chain of Campylobacter fetus serotype A lipopolysaccharide is a partially O-acetylated 1,3-linked alpha-D-mannan.

A polysaccharide fraction liberated from Campylobacter fetus subsp. fetus serotype A lipopolysaccharide by mild acid hydrolysis followed by gel-permeation chromatography contained a partially O-acetylated D-mannan chain, as an O-specific polysaccharide, with a core oligosaccharide attached. The structure of the polysaccharide was studied by O-deacetylation, methylation, and 1H- and 13C-NMR spectroscopy, including computer-assisted analysis of the 13C-NMR spectrum. A structure of -->3)-alpha-D-Manp2Ac-(1--> was established as the structure of the O-specific polysaccharide, the degree of O-acetylation of the mannose residues at position 2 being estimated as 80-90%. As judged by the ratio of mannose to core constituents, the D-mannan chain consists on average of 10-12 monosaccharide units.

Acetylation↗
PubMed1997

Structure of the capsular polysaccharide from Alteromonas nigrifaciens IAM 13010T containing 2-acetamido-2,6-dideoxy-L-talose and 3-deoxy-D-manno-octulosonic acid.

A capsular polysaccharide was obtained from Alteromonas nigrifaciens IAM 13010T by saline extraction. On the basis of 1H and 13C NMR spectroscopy, including one-dimensional (1D) NOE spectroscopy, 2D rotating-frame NOE spectroscopy (ROESY), and 1H-detected heteronuclear 1H,13C multiple-quantum coherence (HMQC), it was concluded that the polysaccharide contained inter alia an acidic sugar, 3-deoxy-D-manno-octulosonic acid (Kdo), and a rare amino sugar, 2-acetamido-2,6-dideoxy-L-talose (L-6dTalNAc, N-acetylpneumosamine), and has a pentasaccharide repeating unit of the following structure: [equation: see text]

Carbohydrate Conformation↗
PubMed1997

Structure of the O-specific polysaccharide of Proteus penneri strain 25 containing N-(L-alanyl) and multiple O-acetyl groups in a tetrasaccharide repeating unit.

Based on sugar and methylation analyses, O-deacetylation, Smith degradation, and 1H and 13C NMR spectroscopy, including 2D COSY, 1H-detected 1H, 13C heteronuclear single-quantum coherence (HSQC), and 1H-detected 1H, 13C heteronuclear multiple-bond connectivity (HMBC) experiments, the following structure of the O-specific polysaccharide of Proteus penneri strain 25 was established: [formula: see text] where D-GlcN(L-Ala) is 2-(L-alanylamido)-2-deoxy-D-glucose.

Acetylation↗
PubMed1997

Structural and serological studies of the O-antigen of the bacterium Proteus mirabilis OXK (serogroup O3) used in the Weil-Felix test.

Sugar analysis and 1H- and 13C-NMR spectroscopic studies showed that various strains of Proteus mirabilis OXK used as antigens in the Weil-Felix test for serodiagnosis of rickettsiosis (scrub typhus) produce lipopolysaccharides (LPSs) with the same O-specific polysaccharide chain having the following structure: [formula: see text] where GlcA and GalA are glucuronic and galacturonic acids, respectively. This polysaccharide which defines the O3 specificity of Proteus and has been found earlier in an unclassified P. mirabilis strain S1959, contains an amide of D-galacturonic acid with L-lysine which plays an important role in manifesting the immunospecificity. A cross-reaction was observed in ELISA between sera from patients with scrub typhus, caused by the bacterium Orientia (Rickettsia) tsutsugamushi, and purified LPS of P. mirabilis OXK, thus suggesting that the common epitope involved in the Weil-Felix test is located on P. mirabilis OXK LPS. Rabbit anti-P. mirabilis OXK antibodies did not cross-react with LPS-lacking O. tsutsugamushi strain Gilliam in dot-blotting and Western blotting, and the nature of the rickettsial antigen responsible for the Weil-Felix reaction remains unknown.

Carbohydrate Conformation↗
PubMed1997

Structure of the acid-labile galactosyl phosphate-containing O-antigen of the bacterium Proteus vulgaris OX19 (serogroup O1) used in the Weil-Felix test.

The structure of the O-specific polysaccharide chain of Proteus vulgaris OX19 lipopolysaccharide which determines the O1 specificity of Proteus and is used in the Weil-Felix test for diagnostics of rickettsiosis was established. On the basis of 1H- and 13 C-NMR spectroscopy, including two-dimensional correlation spectroscopy (COSY), H-detected 1H, 13C heteronuclear multiple-quantum coherence (HMQC), and rotating-frame nuclear Overhauser effect spectroscopy (ROESY), it was found that the polysaccharide consists of branched pentasaccharide repeating units containing D-galactose, 2-acetamido-2-deoxy-D-glucose, 2-acetamido-2-deoxy-D-galactose, and 2-acetamido-2,6-dideoxy-D-glucose (QuiNAc, two residues), which are connected to each other via a phosphate group (P): [formula: see text]. The polysaccharide is acid-labile, the glycosyl phosphate linkage being cleaved at pH 4.5 (70 degrees C) to give a phosphorylated pentasaccharide with a galactose residue at the reducing end. Structural analysis of the oligosaccharide and a product of its dephosphorylation with 48% hydrofluoric acid using 1H- and 13C-NMR spectroscopy and electrospray ionization mass spectrometry confirmed the structure of the polysaccharide.

Carbohydrate Conformation↗
PubMed1997

Structure of the O-specific polysaccharide of the bacterium Providencia alcalifaciens O23 containing a novel component: an amide of D-glucuronic acid with N(epsilon)-(1-carboxyethyl)lysine.

An acidic O-specific polysaccharide was obtained by mild acid degradation of the lipopolysaccharide of the bacterium Providencia alcalifaciens O23 and found to contain D-glucose, D-galactose, 2-acetamido-2-deoxy-D-galactose, and N epsilon-(1-carboxyethyl)-N alpha-(D-glucuronoyl)lysine. On the basis of full and partial acid hydrolyses, selective solvolysis with anhydrous hydrogen fluoride, and 1H- and 13C-NMR spectroscopy, including two-dimensional correlation spectroscopy (COSY), H-detected heteronuclear 1H, 13C multi-quantum coherence (HMQC), and rotating-frame nuclear Overhauser effect spectroscopy (ROESY), the following structure of the liner tetrasaccharide repeating unit of the polysaccharide was established [structure: see text]

Amides↗