Correlation between subgingival microflora and peptidase activity in periodontal pockets measured with synthetic substrates

Abstract

The activity of peptidases in periodontal pockets of patients were examined by using four different synthetic enzyme substrates, and surveyed their correlation with the microbial populations of subgingival plaque and clinical symptoms. The substrates were (1) alpha-N-benzoyl-DL-arginine-beta-naphthylamide (BANA), (2) N-carbobenzoxy-glycylglycyl-arginine-4-methoxy-beta-naphthylamide, (3) alpha-N-benzoyl-L-arginylglycyl-L-phenylalanyl-L-proline-4-methoxy -beta-naphthylamide and (4) N-carbobenzoxy-prolyl-L-alanylglycyl-L-proline-4-methoxy-beta naphthylamide. Whereas substrates (1) and (2) were hydrolyzed more specifically by peptidases of mainly Bacteroides gingivalis and Treponema denticola, substrates (3) and (4) were susceptible to most of the strains of black-pigmented Bacteroides, Capnocytophaga and T. denticola. Correlation between the peptidase activity and the level of Spirochetes in the plaques were observed with the substrates (1), (2) and (3). Substrate (3) had the strongest correlation also with the level of the black-pigmented Bacteroides and with the depth of the periodontal pockets, suggesting that it is a better substrate for enzymatic diagnosis than BANA which is currently used as an indicator of oral Spirochetes and the black-pigmented Bacteroides.