title: Characteristics of a protease of Streptococcus sanguis G9B which degrades the major salivary adhesin.
abstract: An endogenous enzyme present in cell surface extracts of Streptococcus sanguis strain G9B degraded the major salivary adhesin of the organism. The enzyme showed optimal activity between 50 and 65 degrees C and was inactivated at higher temperatures. The activity at these unusually high temperatures seemed to be a consequence of release from the cell surface since intact whole G9B cells showed greater activity at 37 degrees C. The enzyme was not found in culture supernatants of G9B cells. The pH range for the enzyme was between 5 and 9. It was inhibited by iodoacetic acid, Hg2+, Cu2+, EDTA, SDS, and PMSF, but not by TLCK, TPCK, soybean trypsin inhibitor, cysteine, dithiothreitol, leupeptin, Ca2+, Mg2+ or saliva. The enzyme did not show any activity against human or rabbit IgG or human IgA. Enzyme activity was also found in S. sanguis strains Adh- (a spontaneously occurring non-adherent mutant of G9B), and M-5.
authors.affiliation: Department of Microbiology, School of Dental Medicine, University of Pennsylvania, Philadelphia 19104.
authors.forename: R J
authors.initials: RJ
authors.lastname: Lamont
authors.forename: B
authors.initials: B
authors.lastname: Rosan
mesh_terms: D018829:Adhesins, Bacterial; D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D010447:Peptide Hydrolases / Q000032:analysis*; D011817:Rabbits; D012463:Saliva / Q000382:microbiology*; D013298:Streptococcus sanguis / Q000201:enzymology*; D013696:Temperature
chemical_list: D018829:Adhesins, Bacterial; D001426:Bacterial Proteins; D010447:Peptide Hydrolases