Proteolytic activity among various oral Treponema species and cloning of aprtP-like gene of Treponema socranskii subsp socranskii

The proteolytic activity of 11 treponemal strains representing different ph ylogenetic groups was investigated by SDS-polyacrylamide gel electrophoresi s with copolymerised casein, gelatin and fibrinogen as substrates. The acti vity was specified to be trypsin- and chymotrypsinlike by the cleavage of s ynthetic substrates BAPNA and SAAPFNA, respectively. Nine strains degrade c asein and the synthetic substrate BAPNA. Chymotrypsin-like activity specifi cally inhibited by phenylmethylsulfonyl fluoride was found in four treponem es. Southern blot analysis using a Treponema socranskii subsp. socranskii-s pecific prtP probe confirmed the presence of prtP homologous genes in these four strains. The internal fragments of the chymotrypsin-like protease gen es were cloned and sequenced after PCR amplification. Here we report the cl oning of the complete prtP-like gene of T socranskii subsp. socranskii, an organism shown to possess epidemiologic relevance in periodontitis. (C) 200 1 Federation of European Microbiological Societies. Published by Elsevier S cience B.V. All rights reserved.