DIRECT EXTRACTION OF COLLAGENASE FROM HUMAN POST-BURN WOUND TISSUES

Abstract

A fairly high collagenase activity was extracted directly from human post-burn granulation tissues with isotonic sucrose and 4 M urea solutions. Activity of two other enzymes involved in collagen metabolism, i.e., elastase and gelatinase, was also detected in both sucrose and urea extracts along with the collagenase activity. A considerable amount of hydroxyproline, which corresponded to about 10% of the total collagen in the granulation tissues, was found in an isotonic sucrose extract, implying the in vivo degradation of tissue collagen. The collagenase broke down type I collagen preferentially in comparison to type III. A significant correlation (r=0.66; P<0.001) was observed between total collagenase activity and the ratio of type III to type I collagen in post-burn wound tissues. Together with the ratio of type III to type I collagen, activity of all three enzyme in post-burn granulation tissues were decreased significantly 2 weeks after autografting. These results suggest that the preferential degradation of type I collagen by collagenase might be the major event underlying the elevation of the ratio of type III to type I collagen in granulation tissues.