Extraction and partial characterization of a low molecular weight collagenase from normal rat kidney.

A matrix metalloproteinase with selective affinity for collagen was identified and partially purified from normal rat kidney. A two-step purification procedure consisting of gel filtration and affinity chromatography on Sepharose 4B-collagen resulted in an increase in specific activity of more than 3,000 times. The partially purified collagenase cleaved type I collagen and also showed low gelatinolytic activity. The enzyme required Ca2+ and revealed a neutral pH optimum; it was not inhibited by thiol or serineprotease inhibitors. Its activity was fully blocked using recombinant tissue inhibitor of metalloproteinases-1. Using SDS-PAGE and zymography, the estimated Mr of the collagenase was 16.5 x 10(3).