ISSN:
1600-0765
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Bacteroides gingivalis produces large amounts of proteolytic enzymes which may play a role in its virulence. These enzymes may participate in the tissue destruction of the inflammatory process. In this study, the characteristics of two such enzymes, N-CBz-glycyl-glycyl-arginyl peptidase (N-CBz-Gly-Gly-Arg peptidase) and glycyl-prolyl peptidase (Gly-Pro peptidase) were investigated. The enzymes eluted in different peaks from an anion exchange column. N-CBz-Gly-Gly-Arg peptidase was associated with cells up to 48 h in culture. If cultured longer, it also released in the supernatant. It exhibited optimal activity between pH of 7.0 and 7.5 and was readily inactivated by heat treatment (45°C for 15 min). The enzyme activity was inhibited by p-chloromercuribenzoic acid (PCMB), leupeptin and antipain, suggesting that it is a thiol protease. The B. gingivalis N-CBz-Gly-Gly-Arg peptidase was different from the serum enzyme that digests the same substrate. The serum enzyme was more resistant to heat treatment and was inhibited by diisopro-pylfluorophosphate (DFP). B. gingivalis also produced Gly-Pro peptidase that is released in the supernatant. The enzyme has an optimal pH range between 7.5 and 8.0. The B. gingivalis Gly-Pro peptidase was inhibited by DFP, suggesting that it represents a serine protease. The serum Gly-Pro peptidase did not differ from the bacterial enzyme with respect to its sensitivity to inhibitors; however, they were markedly different in heat sensitivity. The bacterial enzyme was completely inactivated at 60°C for 30 min, whereas the serum enzyme was not inactivated even at 1 h at 60°C.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1600-0765.1987.tb01608.x
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