Direct production of an activated matrix metalloproteinase-9 (gelatinase B) from mammalian cells

Matrix metalloproteinase-9 (MMP-9) is produced by the inactive proform and activated by a proteolytic process. However, it has not been reported to pr oduce the active form directly from cells, which has hindered the research to elicit the physiological roles of this enzyme. In this study, we prepare d mutant MMP-9 containing the furin-recognizing sequence in the prodomain a nd showed that the mutant MMP-9 was secreted as the active form directly fr om CHO-KI cells and primary hepatocytes after the gene was transfected. The secreted MMP-9 showed proteolytic activity without further activation and degraded collagen IV in vitro. In addition, the transfection of the gene in to the liver resulted in the efficient expression of active MMP-9 in the li ver and the serum in vivo. (C) 2001 Published by Elsevier Science B.V. on b ehalf of the Federation of European Biochemical Societies.