Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.64 (proteinase K)
 4,071 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A total of 192 hybridomas were developed from mice immunized with Rickettsia japonica, a newly identified spotted fever group rickettsia pathogenic for humans. Of these hybridomas, 101 were species specific, 37 were spotted fever group reactive, and the other 54 were also reactive with one or more of the other pathogenic species of spotted fever group rickettsiae, Rickettsia akari, Rickettsia australis, Rickettsia conorii, Rickettsia rickettsii, and Rickettsia sibrica. Seven of the species-specific monoclonal antibodies were characterized. These monoclonal antibodies all belong to the immunoglobulin G class and react with all five strains of R. japonica at the same immunofluorescence titers, indicating that the five strains all belong to a single species. The species-specific epitopes reactive with these monoclonal antibodies are located on the surface proteins of the organisms demonstrated as 145- and 120-kilodalton bands on Western immunoblots. These two antigenic bands were shown to be proteins, because treatment with proteinase K completely destroyed the reactivity of the bands with the monoclonal antibodies.
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PMID:Species-specific monoclonal antibodies to Rickettsia japonica, a newly identified spotted fever group rickettsia. 169 80

Thirty-eight monoclonal antibodies that have not been reported previously were developed from mice immunized with Rickettsia rickettsii, R. conorii, and R. sibirica. Western immunoblotting showed that these monoclonal antibodies are directed against heat-sensitive epitopes which are located on two major surface polypeptides with molecular sizes ranging from 115 to 150 kilodaltons. The detection of the two bands did not depend on the presence of 2-mercaptoethanol. Both bands were destroyed by treatment with proteinase K. Monoclonal antibodies examined by immunofluorescence assay reacted with epitopes that are species specific, group reactive, or shared among a smaller subset of species of spotted fever group rickettsiae. Nine of the monoclonal antibodies were evaluated for their ability to neutralize rickettsial infection and thus protect animals against disease caused by homologous species of rickettsiae. Treatment of rickettsiae with monoclonal antibodies F3-12, F3-14, and F3-36 completely protected guinea pigs against illness caused by the homologous organism R. rickettsii. Monoclonal antibodies F9-5G11 and F15-5B12, derived from mice immunized with R. sibirica, conferred partial protection by delaying the onset and shortening the duration of fever in guinea pigs inoculated with R. sibirica. Monoclonal antibodies F2-15, F2-31, F2-53, and F3-12 protected mice from a lethal infection with R. conorii. Heat-labile epitopes of spotted fever group rickettsial surface proteins are important candidate antigens for development of vaccines to confer protective immunity.
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PMID:Protective monoclonal antibodies recognize heat-labile epitopes on surface proteins of spotted fever group rickettsiae. 245 18

Four monoclonal antibodies from euthymic mice and two monoclonal antibodies from athymic mice were directed against antigens of Rickettsia conorii, as shown by both indirect immunofluorescence and an enzyme immunoassay. There was extensive cross-reactivity with other spotted fever group rickettsiae. Euthymic monoclonal antibodies 3-2 and 9-2 (immunoglobulin G2a [IgG2a]) and 27-10 (IgG1) distinctly outlined the acetone-fixed rickettsial surface, as determined by indirect immunofluorescence; only monoclonal antibody 3-2 reacted with the intact rickettsial surface, as determined by colloidal gold-protein A negative-stain electron microscopy. Athymic monoclonal antibodies 32-2 and 35-3 (IgM) and euthymic monoclonal antibody 31-15 (IgG3) all demonstrated an irregular, extrarickettsial morphology, as determined by immunofluorescence, and ultrastructural cell wall blebs that were readily shed from the rickettsial surface. Monoclonal antibody 3-2, the only antibody to confer protection in lethally challenged mice, reacted with a high-molecular-weight protein in Western immunoblots. Monoclonal antibodies 31-15, 32-2, and 35-3 reacted with a "ladder" of proteinase K-resistant, lipopolysaccharidelike antigens. None of the monoclonal antibodies stabilized the ultrastructural rickettsial slime layer, but both athymic and euthymic polyclonal antibodies to R. conorii did. This is, to the best of our knowledge, the first report of the production of monoclonal antibodies to R. conorii and their use for antigenic analysis.
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PMID:Analysis of T-cell-dependent and -independent antigens of Rickettsia conorii with monoclonal antibodies. 379 35

An enzyme-linked immunosorbent assay for detecting human immunoglobulin G to spotted fever group rickettsiae was developed and tested. The assay uses proteinase K-resistant material, characteristic of the rickettsial lipopolysaccharides shown to be group specific by immunoblots, as the antigen. The results indicate that the assay provides a sensitive, yet specific, alternative method for diagnosing rickettsial diseases.
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PMID:Enzyme-linked immunosorbent assay for detection of human immunoglobulin G to lipopolysaccharide of spotted fever group rickettsiae. 841 18

Cross-reactivity between Rickettsia japonica and R. typhi was observed by immunofluorescence tests using sera from patients with Oriental spotted fever (OSF), from whom the causative agent was isolated and identified as R. japonica. Western immunoblotting with these sera revealed that only the 120-kilodalton surface polypeptide, i.e., rickettsial outer membrane protein (rOmp) B, has a common antigenicity with the 105-kilodalton surface polypeptide of R. typhi. In some cases, antibodies specifically reactive with R. typhi were detected in acute-phase sera followed by a significant rise in titers, possibly because of an anamnestic response to a previous infection with an R. typhi-like agent; the sera retained reactivity to R. typhi even after absorption by a homologous strain. A lipopolysaccharide (LPS)-like antigen of R. typhi was found to be reactive with some sera of OSF patients. The ladder bands on Western immunoblot of rickettsial organisms were confirmed to be polysaccharide in nature, which was demonstrated by comparing them with the pattern of silver-stained gel of proteinase K-treated rickettsial specimens after sodium dodecyl sulfate-polyacrylamide gel electrophoresis.
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PMID:Cross-reactivity of Rickettsia japonica and Rickettsia typhi demonstrated by immunofluorescence and Western immunoblotting. 878 54