Activation of human progelatinase A by collagenase and matrilysin: Activation of procollagenase by matrilysin

Abstract

Proteolytic and nonproteolytic methods were used to investigate the mechanism(s) by which human fibroblast progelatinase A and fibroblast-type procollagenase can be activated. Both collagenase and matrilysin were able to activate progelatinase A, resulting in an amino terminus in gelatinase A of Tyr.⁸¹ The cleavage occurred distal to Cys⁷³ within the sequence of PR_CGNPDVAN⁸⁰-Y⁸¹NFFPRKP. While several nonproteolytic reagents were tested, only the heavy metal Hg(Π) andp-chloromercuribenzoate (PCMB) were able to induce activation of progelatinase A and resulted in the conversion of the latent 72-kDa gelatinase A to an active form of about 64.5 kDa. Matrilysin was also able to activate procollagenase and resulted in an amino terminus in collagenase of Phe.⁸¹ These results suggest that fibroblast-type collagenase and matrilysin may be physiologically relevant activators of progelatinase A; the maintenance of latency and the process of activation for progelatinase A may occur through the cysteine-switch mechanism, and the proteolytic activation of procollagenase by matrilysin resulted in the same amino terminus as produced by stromelysin-1.