Publications by authors named "Fedoreeva L"

Interactions, of porin a protein from Yersinia pseudotuberculosis, with S- and R-LPS and lipid A were investigated by means of fluorescence and CD-spectroscopy, differential scanning microcalorimetry and CsCl gradient ultracentrifugation. S-LPS--porin monomer stoichiometry was shown by fluorescence titration to be 6:1. Ultracentrifugation data suggest that the maximum number of LPS molecules bound per porin monomer in three.

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Interaction of the major outer membrane protein form Yersinia pseudotuberculosis with lipid A was investigated by intrinsic fluorescence, CD spectroscopy and CsCl gradient centrifugation methods. The protein was shown to have two independent binding sites with an association constant 6.1 x 10(4) M-1.

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By means of physico-chemical methods, lipid bilayer reconstitution and immunoenzyme assay, macromolecular organization of porin oligomers from Yersinia pseudotuberculosis, isolated by two extraction methods, was studied. Use of SDS and high temperature in the course of the extraction led to a partial denaturation of porin trimers at the level of the tertiary structure, these conformational changes affecting the porin's pore-forming activity and antigenic structure. At the same time, the partially denatured trimers are as stable under the treatment of urea and guanidine hydrochloride as the native protein.

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The protein moiety of endotoxin from Yersinia pseudotuberculosis was found to consist of two polypeptides with apparent molecular masses 40 and 14.5 kDa (4:1 w/w). The major protein (40 kDa) was isolated from the endotoxin pretreated with sodium deoxy cholate by gel chromatography on the Sephadex G-200 column.

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A major protein of the endotoxin from Yersinia pseudotuberculosis was isolated from the complex lipid A--protein by treatment with SDS and triton X-100 followed by gel-chromatography on Sephacryl S-300. Protein has apparent molecular mass 40 kDa and alanine as N-terminal amino acid residue. CD and IR spectroscopy conformational changes of the protein molecule in the process of its isolation.

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Lipopolysaccharide-protein complexes are shown to be useful for elucidation of O-specific polysaccharide structures. This approach may be especially useful in studying polysaccharides with labile linkages in the molecule.

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Mild acid hydrolysis of endotoxin of Yersinia pseudotuberculosis afforded a lipid A--protein complex composed of amino acids and all characteristic components of lipid A: glucosamine, dodecanoic, 3-hydroxytetradecanoic acids and phosphorus in a molar ratio of 2 : 1,5 : 2,8 : 1,7, respectively. The protein component of the complex was shown by gel electrophoresis in the presence of sodium dodecylsulphate to consist of two polypeptides with apparent molecular weights of 12000 and 8000. The lipid A--protein complex cross-reacted with antiserum to endotoxin and lipid A antiserum.

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