| abstract |
Genetically engineered E. coli carry vectors containing inserts that code for Clostridium histolyticum collagenase. These inserts code for: (a) a form of collagenase having a molecular weight of about 68,000 daltons in the essential absence of larger forms of collagenase; (b) the 68 kd form of collagenase and a fusion polypeptide consisting of the collagenase protein fused to at least a portion of the β-galactosidase protein of E. coli; or (c) the 68 kd form of collagenase and polypeptides of molecular weight of from above about 68,000 daltons to about 100,000 daltons and having the enzymatic activity of C. histolyticum collagenase as indicated by digestion of 3H-acetylated collagen and by specific inhibition by 1,10-phenanthroline plus EDTA. The collagenase genes in the transformed E. coli are expressed efficiently in the transformed cells to yield enzymatically active and immunologically cross-reactive collagenase. In particular, the 68 kd form of collagenase is resistant to autocatalytic degradation and is stable to long-term storage. Genetically engineered collagenase, especially the 68 kd form that is resistant to autocatalytic degradation, can be used for isolation of pancreatic islets, for the isolation of dispersed tumor cells, or for treatment of ''slipped disc''. |