title: Purification and characterization of a protease from Bacteroides gingivalis 381.
abstract: An intracellular membrane-free, trypsinlike protease was isolated from cells of Bacteroides gingivalis 381. The protease was extracted from the cells by ultrasonic treatment and was purified about 250-fold with a recovery of 2% by sequential procedures. The properties of the protease were as follows: its optimal pH was 8.5; its activity was almost completely lost on incubation at 50 degrees C for 15 min; its activity was inhibited by diisopropylfluorophosphate, p-toluenesulfonyl-L-lysine chloromethyl ketone hydrochloride, leupeptin, Mn2+, Cu2+, and Zn2+; it hydrolyzed casein, azocasein, N-alpha-benzoyl-DL-arginine-p-nitroanilide (BAPNA), bovine serum albumin, azocoll, and gelatin, but not N-alpha-benzoyl-DL-lysine-p-nitroanilide or human serum immunoglobulin A; its molecular weight was estimated as 45,000 by gel filtration and 50,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis; and its Km values for azocasein and BAPNA were 1.11% and 0.19 mM, respectively.
mesh_terms: D001439:Bacteroides / Q000201:enzymology* / Q000254:growth & development; D002848:Chromatography, DEAE-Cellulose; D003545:Cysteine / Q000494:pharmacology; D006358:Hot Temperature; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008670:Metals / Q000494:pharmacology; D008970:Molecular Weight; D010447:Peptide Hydrolases / Q000302:isolation & purification*; D010510:Periodontal Diseases / Q000382:microbiology
chemical_list: D008670:Metals; D010447:Peptide Hydrolases; D003545:Cysteine