The rates of cleavage of insoluble and soluble collagens by tissue collagenases.

The cleavage rates of insoluble and acid-soluble bovine collagens by tissue collagenases from the cultures of C3H mouse mammary adenocarcinoma and from human rheumatoid synovial fibroblasts at 37 degrees C were compared by measuring dansyl (Dns)-IIe and Dns-Leu, amino-terminal residues at the cleaved sites after dansylation. The kinetic parameters, Kcat and Km, defined functionally, were as follows: for insoluble Achilles tendon collagen, Km values were 0.89 and 0.83 microM; Kcat/Km 39.2 and 317 microM-1 h-1. For acid-soluble skin collagen the values were 0.83 and 0.82 microM; 44.6 and 354 microM, respectively. The supernatants from the insoluble and acid-soluble collagens contained 28% and 92% of total Dns-IIe and 1.3% and 43% of total Hyp, respectively. Results showed that both tissue collagenases cleaved insoluble collagen almost as rapidly as they did reconstituted collagen fibrils. The cleavage of collagen was proportional to enzyme concentration. The presence of Dns-IIe and Dns-Leu in the supernatant arises from a second cleavage of the collagen molecule.