Transformed human fibroblasts secrete two structurally and functionally related inhibitors of matrix metalloproteinases, tissue inhibitor of metalloproteinases (TIMP) 1 and 2. In assays measuring the relative inhibitory capability of TIMP-1 and TIMP-2 against autoactivated 72-kDa gelatinase, which consists of two major active peptides and several inactive fragments, TIMP-2 was more effective th...