title: [Immunochemical characterization of Fraction I of Yersinia pestis strains by CAF1M gene].
abstract: The role of caf1M gene in biogenesis of Yersinia pestis capsule was studied in natural strains of the agent with Fra+/- phenotypes and recombinant variants with ycaA (caf1+;caf1M;caf1A+;caf1R+) locus defect. These bacteria did not form a clearly discernible capsule stained by classical methods but synthesized Cafl, whose content in the cells was many times higher than in lysates, in external cell wall, and in the medium with reference Y. pestis EV NIIEG culture (caf1+;caf1M;caf1A+;caf1R+). However Caf1 was not detected on the surface or culture fluid of natural and mutant Y. pestis cells. Exclusive role of Caf1M in Caf1 delivery to Y. pestis cell surface, but not in F1 monomer folding, was proven. Retention of lipopolysaccharide (LPS), a typical SR-LPS configuration and epitope specificity of its components was demonstrated, ensuring similar reactivity in solid-phase enzyme immunoassay with a panel of monoclonal antibodies to Y. pestis LPS. Study of immunochemical properties of antigenic substances derived from caf1M-defective Y. pestis cells by isolation of F1 showed that these substances represent an envelope protein involved in the caf1+ strains (together with Caf1) in assembly of "mature" F1 molecule as a result of posttranslation modification of various genes products. Variants of identification of Y. pestis with Fra+ phenotype by means of monoclonal antibodies to F1, fibrinolysis/coagulase, or LPS in solid-phase enzyme immunoassay are discussed.
authors.affiliation: Russian Plague Control Institute Mikrob, Saratov.
authors.forename: V A
authors.initials: VA
authors.lastname: Fedorova
authors.forename: Z L
authors.initials: ZL
authors.lastname: Devdariani
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000235:genetics*; D001426:Bacterial Proteins; D008070:Lipopolysaccharides / Q000737:chemistry / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D018832:Molecular Chaperones / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D021381:Protein Transport; D015010:Yersinia pestis / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D008070:Lipopolysaccharides; D018832:Molecular Chaperones; C070195:CAf1M protein, Yersinia pestis