To clarify the pathogenic role of proteinases from Porphyromonas gingivalis
, a 45 kDa proteinase was isolated from P. gingivalis culture medium by a c
ombination of gel filtration (Bio-Gel A-0.5 m) and ion-exchange chromatogra
phies (DEAE-Sephacel and SP-Sepharose FF). The enzyme was found to have a m
olecular mass of 45 kDa by SDS-PAGE and to require mercaptoethanol for its
activation. The 45 kDa proteinase cleaved T-kininogen into small fragments,
but failed to release kinin. In contrast, T-kininogen inhibited the Arg-am
idolytic activity of the 45 kDa proteinase with a K-i of 2 nM. On the other
hand, the 45 kDa proteinase did not stimulate the production of PGE(2), IL
-1 beta, and TNF-alpha from the macrophages. (C) 1999 Published by Elsevier
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