Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To date, tissue sections prepared from Formalin-fixed tissues have not been successfully stained with Treponema pallidum subspecies-specific antibody in a direct fluorescent-antibody assay. While current methods stain T. pallidum, they do not distinguish T. pallidum from other spirochetes such as Borrelia burgdorferi (E. F. Hunter, P. W. Greer, B. L. Swisher, A. R. Simons, C. E. Farshy, J. A. Crawford, and K. R. Sulzer, Arch. Pathol. Lab. Med. 108:878-880, 1984). Because trypsin pretreatment of tissue sections has enhanced other immunofluorescent-antibody (IFA) applications, we compared the use of the trypsin digestion method with the current 1% ammonium hydroxide (NH4OH) method as a means to obtain specific staining of T. pallidum in tissues by both direct and indirect IFA techniques. Pretreated T. pallidum-infected tissues sections from rabbits, hamsters, and humans were quantitatively examined with the direct fluorescent-antibody-T. pallidum test conjugate absorbed with Treponema phagedenis, the Reiter treponeme. For indirect staining, a serum specimen from a patients with syphilis absorbed by affinity chromatography with T. phagedenis was used as the primary reagent, and a fluorescein isothiocyanate-labeled rabbit anti-human globulin was used as the secondary reagent. Serum specificity was established first by examining antigen smears of T. pallidum subsp. pallidum, T. pallidum subsp. pertenue, B. burgdorferi, T. phagedenis, and Treponema denticola MRB and then by examining tissues infected with these pathogens plus those infected with four Leptospira serovars. When we stained tissue using the direct IFA method that is currently a standard method for the examination of chancre smears, we found it to be unsuitable for use with tissue. Trypsin digestion did not offer an improvement over the NH4OH pretreatment method in the specific identification of T. pallidum by direct IFA. However, specific identification of T. pallidum in tissue sections was obtained by the indirect IFA technique after either trypsin or NH4OH pretreatment.
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PMID:Specific immunofluorescence staining of Treponema pallidum in smears and tissues. 170 44

MRB, a major R222 plasmid-encoded protein previously described by us, is synthesized in large amounts in host Escherichia coli cells, where it is located principally in the outer membrane. Most of this protein is also bound to the peptidoglycan layer in a form which is trypsin resistant. Its monomeric molecular weight is about 29,000, but it is isolated from cell membranes in aggregate molecular weights of more than 100,000. These properties demonstrate a strong similarity between MRB and porins, major outer membrane proteins of host E. coli cells. They suggest that MRB may have an as-yet unidentified transport function, as do cellular outer membrane proteins with similar biochemical properties. By using antiserum specific for MRB, we demonstrated identity between MRB and the product of the traT gene, one of the surface exclusion proteins on the F plasmid. The synthesis of MRB was found to be constitutive, in contrast to other tra genes, which appear to be under more rigid regulation by the tra operon. These findings suggest that on R222 and other F-like R plasmids this protein has its own promoter.
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PMID:Biochemical and immunological characterization of an R plasmid-encoded protein with properties resembling those of major cellular outer membrane proteins. 699 44