Hydrolysis of the Leu-Gly bond of phenylazobenzyl-oxycarbonyl-<span style="font-variant:small-caps">l</span> -Pro-<span style="font-variant:small-caps">l</span> -Leu-Gly-<span style="font-variant:small-caps">l</span> -Pro-<span style="font-variant:small-caps">D</span> -Arg (a substrate of microbial collagenases) by treponemes isolated from the subgingival plaque of periodontitis patients

Abstract: Cell extracts prepared from several oral treponemes isolated from the subgingival plaque of periodontitis patients showed high enzyme activity toward phenylazobenzyl-oxycarbonyl-l-prolyl-l-leucylglycyl-l-prolyl-d-arginine (a compound used as a substrate for microbial collagenases). One major enzyme hydrolyzing this substrate at the Leu-Gly bond only was partially purified from an unspeciated treponeme (strain US),Treponema denticola ATCC 35405, and 29 different clinical isolates ofT. denticola. TheTreponema US enzyme also hydrolyzed furylacryloyl-l-leucylglycyl-l-prolyl-l-alanine (another substrate of bacterial collagenases) at the Leu-Gly bond. This enzyme also hydrolyzed various collagens and collagen-derived peptides. These treponemal proteases were sensitive to metal chelators andp-chloromercury compounds. The results indicate that human oral treponemes contain enzymes that readily hydrolyze in chromogenic protease substrates the Leu-Gly bond only that is the cleavage site of these substrates also by ldquotruerdquo microbial collagenases.