| Abstract: | Several fibrinolytic activities of Treponema denticola, an oral spirochete associated with gingivitis and periodontal disease, were identified and characterized following phase partitioning with the nonionic detergent Triton X-114. The apparent molecular masses of the proteases ranged from 91 to 228 kDa when analyzed in sodium dodecyl sulfate-polyacrylamide gels containing fibrinogen as the protease substrate. A qualitative analysis of zymograms showed that the proteases were highly enriched in the detergent phase, although the 91-, 173-, and 228-kDa proteases were also found in the aqueous phase. Zymograms of crude outer sheaths prepared by repeated freezing-thawing revealed that the proteases may be associated with this subcellular compartment. The proteases displayed substrate specificity towards fibrinogen, were susceptible to sulfhydryl group reagents, and had a pH optimum between 7 and 8. The similarities in their sensitivity to inhibitors, temperature stability, pH optimum, and laddered protein profiles suggest that these hydrolytic enzymes may be part of a family of oligomeric proteases that may play an important role in the invasiveness of and tissue damage caused by the spirochete. |
