Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0272170 (SDS)
 50,377 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The association-dissociation processes involving the capsule antigen of Yersinia pestis were investigated. In aqueous salt solutions the material of the capsule (protein F1) exists in the form of associated species containing identical monomeric protein subunits. Brief heating (100 degrees C, 3 min) of F1 dissolved in buffered salt solutions at pHs between 4.4 and 7.5 leads to dissociation of the antigen into oligomers which reassociate at room temperature into aggregates of high molecular mass. In the presence of 7 M urea and 0.1% SDS such reassociation is suppressed. It is shown that a few seconds after heat treatment the protein exists as the tetramer in phosphate buffer and as the dimer and the monomer in the presence of urea and SDS respectively. Interconversions of these three forms of the antigen were observed on replacement of one buffer by another. The effect of pH, ionic strength, F1 concentration, and temperature on the rate of association of F1 were also investigated. A decrease in pH, an increase in the ionic strength of the solution, and an increase in the concentration of the protein in aqueous buffered salt solutions all accelerate the F1 aggregation process. A model is proposed for the supermolecular structure of the F1 protein associated species in which the subunits are assembled into a single plane containing tens of dimers as a result of lateral interdimer hydrogen bonds. The dimer is stabilised by hydrophobic interactions of the nonpolar sections of the subunits, which in the associated protein form an internal hydrophobic surface analogous to that in lipid bilayer membranes.
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PMID:Association-dissociation processes and supermolecular organisation of the capsule antigen (protein F1) of Yersinia pestis. 213 58

In order to investigate arthritis-triggering, serologically cross-reactive antigens, sera from patients infected with arthritis-associated microbes, Salmonellae, Chlamydia trachomatis, and Sindbis-like alphavirus, were reacted against SDS-PAGE separated and immunoblotted Yersinia enterocolitica 0:3 antigens. These sera reacted with Yersinia to the same extent as did the control sera taken from patients with streptococcal, staphylococcal and Bordetella pertussis infections or from healthy blood donors. Moreover, the various sera produced different reactivity patterns, directed against several different antigens. Although sera from test subjects, as well as from controls including healthy individuals, recognized some Yersinia antigens, these patterns differed markedly from those recognized by sera taken from patients with Yersinia infection. Significantly, analysis of the reactivities against the different molecular weight antigen components of Yersinia revealed no dominant band or pattern which could thus have been defined as arthritis-associated.
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PMID:Serological cross-reactions against Yersinia enterocolitica in patients infected with other arthritis-associated microbes. 216 7

Cell extracts of Yersinia ruckeri (serotype I) were examined by SDS-PAGE and Western blotting. An unusual band, termed heat-sensitive factor (HSF) was observed in extracts of virulent strains only. It is thought to be lipid in nature; no differences could be detected in the region of the band in protein profiles of virulent and avirulent strains. When trout were infected either by intraperitoneal injection or bath immersion, mortalities occurred only with HSF+ strains. The HSF appears to be an important virulence determinant of Y. ruckeri.
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PMID:Virulence of Yersinia ruckeri serotype I strains is associated with a heat sensitive factor (HSF) in cell extracts. 232 44

The outer membranes of gram-negative bacteria are considered to be of importance in host-bacteria interaction, in protective immunity, and occasionally in subclassification within a species. In this study, the outer membranes of several strains of Yersinia enterocolitica and Y. pseudotuberculosis were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). It was found that the appearance of the major proteins depended on the temperature at which they were solubilized in SDS. A protein was identified with the use of two-dimensional gels and preparative SDS-PAGE, which was equivalent to the "heat-modifiable protein" (protein II) of other Enterobacteriaceae species. A monoclonal antibody, 4G1, was generated against an isolated preparation of this Y. enterocolitica protein. This antibody was tested with whole cell bacterial antigens of 46 individual bacterial strains. The reactive strains included only Y. enterocolitica and Y. pseudotuberculosis. In addition, the reactivity of the 4G1 monoclonal antibody preparation could be absorbed only with Y. enterocolitica and Y. pseudotuberculosis, and not with other strains of bacteria. The reactivity of this 4G1 monoclonal antibody was also tested by the Western Blot technique. Six individual strains were tested: a Y. enterocolitica serotype 0:3, a Y. enterocolitica serotype 0:9, an Escherichia coli, a Salmonella typhimurium, a Shigella flexneri, and a Klebsiella pneumoniae. The 4G1 antibody reacted with only the proteins of the two Y. enterocolitica strains. In conclusion, the equivalent of the heat-modifiable protein was present in Y. enterocolitica and Y. pseudotuberculosis. Moreover, this protein also carried a species-specific antigenic determinant.
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PMID:A heat-modifiable outer membrane protein carries an antigen specific for the species Yersinia enterocolitica and Yersinia pseudotuberculosis. 240 52

The expression of the determinant for the K99 antigen of Escherichia coli in Yersinia enterocolitica avirulent transconjugants D29(pFS239) and L15(pFS239) was confirmed by means of SDS-polyacrylamide gel electrophoresis, double immunodiffusion and Western blotting. The conditions for the expression of K99 antigen genes in Y. enterocolitica and in E. coli were compared. The K99 antigen protein expressed in Y. enterocolitica in the form of pili on the surface of the cells was discussed. This article offers the first description on the expression in Y. enterocolitica of gene from organism other than Yersinia spp.
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PMID:Expression in Yersinia enterocolitica of K99 antigen gene of Escherichia coli. 247 4

It has been suggested that the O-side chains of the lipopolysaccharide (LPS) of serotype 0:3 strains of Yersinia enterocolitica vary quantitatively and qualitatively depending on whether they are cultured at 37 degrees C or 25 degrees C. It is uncertain whether this affects the expression of the serotype-specific antigens that are probably carried on the LPS. We studied this question with a serotype 0:3-specific monoclonal antibody, 2C1. This monoclonal antibody immunoprecipitated a 39K major protein from detergent-solubilized 125I-labeled Yersinia preparation. However, results of Western blot experiments demonstrated that the antigens reactive with 2C1 were not actually the 39K protein but the O-side chains of the LPS. Significantly, reactivity could be detected whether the bacteria were cultured at room temperature or at 37 degrees C. However, absorption experiments confirmed that there were less accessible antigenic determinants on the 37 degrees C-LPS. The LPS preparations were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and silver staining. These SDS-PAGE profiles showed that less O-side chains were present in the 37 degrees C-LPS. Hence, the most likely explanation for our observation is that the 37 degrees C incubation condition induced a partial smooth to rough transition of the Yersinia LPS with a decrease in the amount of 2C1-reactive antigen.
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PMID:A Yersinia enterocolitica serotype 0:3 lipopolysaccharide-specific monoclonal antibody reacts more strongly with bacteria cultured at room temperature than those cultured at 37 degrees C. 258 49

The outer membrane proteins of 38 Yersinia pestis isolates from all known plague foci of north-east Brazil were analysed by SDS-PAGE. Approximately 20 bands were consistently found in all strains analysed and 11 were selected for comparative studies. Although qualitative differences among the electrophoretic profiles of outer membrane proteins of wild Y. pestis isolates were not observed, quantitative alterations were clearly noted for most of these proteins. No particular quantitative alteration of the electrophoretic profile of outer membrane proteins could be associated with the period of isolation and geographic origin of the isolates. The 64 kDa outer membrane protein was significantly expressed in higher amounts among Y. pestis strains isolated from a recent plague outbreak. The possible use of electrophoretic profiles of outer membrane proteins of wild Y. pestis isolates as a tool for epidemiological studies and for the analysis of virulence determinants is discussed.
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PMID:Electrophoretic characterisation of the outer membrane proteins of Yersinia pestis isolated in north-east Brazil. 260 64

OmpC, one of the major outer membrane proteins of Yersinia enterocolitica, was isolated and purified to homogeneity. When solubilized at room temperature, this protein appeared on SDS polyacrylamide gel electrophoresis as an oligomer. After heating to the temperature of boiling water, the apparent molecular weight of the monomer was 36,000. The incorporation of purified OmpC into black lipid membranes resulted in an increase in membrane conductance demonstrating pore-forming activity. The reconstituted pores exhibited the characteristics of general diffusion pores. They showed cation selectivity and had a single channel conductance of 1.3 nS in 1.0 M KCl. Assuming a constant diameter of the pore, a length of 6 nm (the width of the outer membrane) and the same ion conductivity inside and outside the pore, the diameter of the pore protein was estimated as 1.0 nm. Polyclonal antibodies were raised against the native, pore-forming protein preparation. These antibodies did not recognize the denatured form of the protein, but cross-reacted with native OmpC and OmpF of Escherichia coli. The regulation of OmpC expression in Y. enterocolitica was dependent on the osmolarity of the medium in the same way as in E. coli.
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PMID:The OmpC protein of Yersinia enterocolitica: purification and properties. 262 94

A monoclonal antibody against the Yersinia enterocolitica 60-kilodalton (kDa) antigen, designated cross-reacting protein antigen (CRPA), was obtained by cell fusion. The CRPA common to gram-negative bacteria was purified from Y. enterocolitica by the affinity chromatography with the monoclonal antibody (IgG1) thus obtained. The purified CRPA showed a single band of 60 kDa in SDS-polyacrylamide gel electrophoresis (SDS-PAGE), and reacted with rabbit antisera against Y. enterocolitica, Vibrio cholerae, Escherichia coli, Pseudomonas aeruginosa, and Shigella sonnei in Western blot analysis. The monoclonal antibody, however, reacted with a 60 kDa peptide from Y. enterocolitica, but not with the antigens from other gram-negative bacteria such as V. cholerae, E. coli, S. sonnei, Salmonella enteritidis, Serratia marcescens, Klebsiella pneumoniae, Proteus mirabilis, and P. aeruginosa. The results suggested that both species-specific and cross-reactive epitopes were present on a CRPA molecule.
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PMID:Purification of cross-reacting protein antigen shared by Yersinia enterocolitica and other gram-negative bacteria with monoclonal antibody. 277 74

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. The thermal and pH stabilities of the protein were investigated by the methods of intrinsic fluorescence and differential scanning microcalorimetry. The isolated protein revealed two thermal transitions (at 30-35 and 50-55 degrees C), which depend on Ca2+ concentration.
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PMID:[Isolation and physico-chemical properties of a protein, included in an endotoxin from Yersinia pseudotuberculosis]. 278 72


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