Purification and Characterization of a Potent 70-kDa Thiol Lysyl- proteinase (Lys-gingivain) from Porphyromonas gingivalis That Cleaves Kininogens and Fibrinogen*

摘要: We isolated an enzyme from a major periodontal pathogen, Porphyromonas gingivalis (also called Bacteroides gingivalis), that is capable of initially increasing the coagulant activity high molecular weight kininogen (HK), releasing bradykinin HK and low (LK), destroying light chain (coagulant portion) HK. This enzyme, membrane-bound thiol proteinase preferentially cleaves P1-Lys position tripeptide substrates, also able to rapidly render fibrinogen nonclottable. will refer this as lys-gingivain because its origin P. gingivalis, classification proteinase, action lysyl-amidase. The enhanced by beta-mercaptoethanol, has mass 68-70 kDa, pH optimum 7.4, not inactivated plasma protease inhibitors. second-order rate constant for destruction (surface-binding domain) at 23 degrees C 2.3 x 10(7) M-1 s-1, and, cleavages unclottable, 2.05 10(6) s-1. These data suggest very potent would be fully functional in anaerobic crevices might participate pathogenesis periodontitis. Lys-gingivain appears most kininogenase fibrase described date.