Collagenase from the culture medium of rabbit colon wall with special reference to the latent type and substrate specificity.

Latent and active forms of collagenase were detected in culture media of the normal rabbit colon. During culture, the collagenase appeared to be produced by surviving and growing mucosas on the degenerated or necrotic colon wall. Type III collagen was most readily degraded by the collagenase, followed by type I and II collagens. The collagenase did not attack type IV or V collagens. The latent collagenase was activated by trypsin and chaotropic agents such as 3 M NaSCN or NaI, and autoactivated gradually during storage. Activated latent collagenase showed the properties of metalloproteinase as in the active collagenase. The apparent molecular weights, determined by calibrated Sephadex G-75, were 39,000 and 31,000 for the latent and active enzymes, respectively. After 12 h of tissue culture, the latent collagenase appeared in the culture media 10-20 h earlier than the active collagenase. The collagenase in the culture media of the early period was mainly the latent form, while the media of the late period contained a large amount of the active form.