Benzoylarginine peptidase and iminopeptidase profiles of Treponema denticola strains isolated from the human periodontal pocket

Abstract

Seven clinical isolates and the ATCC strain 35405 of Treponema denticola , obtained from human periodontal pockets, were studied for peptidase activity with several chromogenic compounds as substrates. The cell sonicates of all strains hydrolyzed phenylazobenzyloxycarbonyl- l -prolyl- l -leucyl-glycyl- l -prolyl- d -arginine (a collagenase substrate), azocasein, and the 2-naphthylamines of l -proline, l -hydroxyproline, l -pyrrolidine, and benzoyl- l -arginine, but the rates of hydrolysis varied considerably from strain to strain. Fast protein liquid chromatography on gel and anion exchange columns revealed further biochemical differences between the strains. The ATCC strain consistently produced several proline iminopeptidases, whereas four of the clinical isolates yielded high and three yielded low iminopeptidase activity. The ATCC strain and six clinical isolates displayed high benzoylarginine peptidase activity. The use of N - l -prolyl-2-naphthylamine as substrate revealed more differences between the strains than other substrates. The substrate specificity of the enzymes discovered suggests that they may be important for the nutrition of the organism or in the protection of the organism against chemical defense factors present in the gingival pocket.