Cadmium ions inhibit proollagen C-proteinase and cupric ions inhibit procollagen N-proteinase

Abstract

Procollagen C-and N-proteinases specifically cleave the C- and N-terminal extension propeptides of type I, II and III procollagen molecules. The collage molecules generated by the enzymes self-assemble into collagen fibrils. We previously observed the inhibition of this enzymes purified from thick tendons by severals divalent metals. Here the inhibitory effects of CdCl2, CuCl2,ZnCl2,NiCl2,CoCl2 and Hg(C2H3O2)2 have been studied in detail using crude or purified C- and N-proteinases from chick rendons and sterna. CdCl2 was a strong inhibitor of C-protcinases from both sources, and the inhibition was independent of enzyme purity (I50 = 10-16 μm). In contrast, CuCl2 and ZnCl2 were inhibitory only of purified C-proteinase. With the N-proteinase, CuCl2 was a strong inhibitor, and the inhibition was independent of the purity o the enzyme preparation used (I50 = 14-40μm). On the other hand, CdCl2 was a moderate inhibitor and ZnCl2 was a strong inhibitor only of the purified N-proteinase (I50 = 8 - 17 μm) NiCl2 inhibited crude and purified N proteinase from sternum (I50 = 23-29 μm) but not from tendon. These results suggest, therefore, that the accumulation of some of these metals in the body may cause suppression of collage fibril formation in tissues. © 1994.