Initial characterization of neutral proteinases from oral spirochetes.

Abstract

Intermediate size oral spirochetes were isolated and cultured from subgingival plaque of periodontitis patients utilizing a membrane separation and rifambin selection technique. Neutral salt extracts of the spirochetes were assayed for proteolytic activity against collagen types I and IV, gelatin, and synthetic elastase and trypsin substrates. Type IV collagen obtained from lens capsule basement membrane was degraded to small peptides by the spirochete proteinases. No marked degradation of type I collagen was found when incubations were performed at 25°C. The extracts were able, however, to activate latent collagenase obtained from human gingival fibroblasts and to degrade further the ¼ and ¾ fragments resulting from the collagenase cleavage. Denatured collagen was also degraded by the extracts. High trypsin‐Iike activity and relatively lower elastase‐like enzyme activity were also present in spirochete extracts. The results show that oral spirochetes have a potential for degradation of several proteins and that they may, therefore, have an active role in tissue destruction during periodontal disease.