Purification and characterization of a potent 70-kDa thiol lysyl-proteinase (Lys-gingivain) from Porphyromonas gingivalis that cleaves kininogens and fibrinogen.

Abstract

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

• Authors: C F Scott, E J Whitaker, B F Hammond, R W Colman
• Journal: The Journal of biological chemistry (J Biol Chem) Vol. 268 Issue 11 Pg. 7935-42 (Apr 15 1993) ISSN: 0021-9258 [Print] United States
• PMID: 8385128 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Hydroxyapatites
• Kininogens
• Oligopeptides
• Protease Inhibitors
• Fibrinogen
• Durapatite
• lysyl-gingivain
• Cysteine Endopeptidases

Topics

• Amino Acid Sequence
• Chromatography
• Chromatography, Gel
• Cysteine Endopeptidases (isolation & purification, metabolism)
• Durapatite
• Electrophoresis, Polyacrylamide Gel
• Fibrinogen (metabolism)
• Hydroxyapatites
• Kinetics
• Kininogens (metabolism)
• Molecular Sequence Data
• Molecular Weight
• Oligopeptides (metabolism)
• Porphyromonas gingivalis (enzymology)
• Protease Inhibitors (pharmacology)
• Substrate Specificity