The proposed research concerns the analysis of proteolytic enzymes from anaerobic bacteria commonly associated with periodontal disease. In preliminary studies, Treponema denticola (a small oral spirochete) and Bacteroides gingivalis (B. asaccharolyticus) have been isolated from advanced cases of periodontitis and have been shown to possess activities against a colorimetric trypsin substrate. Most other oral bacteria tested did not have this capability. This proposal will test the hypotheses that these enzymes are (1) present only in the diseased gingival crevice, (2) present only in a limited number of oral bacteria associated with disease, and (3) capable of pathogenic effects against human cells in vitro. The purified enzymes will be tested for collagenase, elastase, and complement activation activities. The enzyme purification and characterization necessary to investigate pathogenesis may produce information leading to improved treatment or diagnosis of periodontal disease.