disclosed are methods of cell surface activation and inhibition that involve the interaction of an inhibitor of matrix metalloprotease known as timp - 2 , with the enzyme , gelatinase - a . critical to the methods of the invention is the discovery of a unique timp - 2 binding site on the surface of the c - terminal domain of the enzyme , which has been determined to be asp 656 , but which can also included other residues in the gela - ctd domain with which asp 656 forms a contiguous surface , namely gly 651 , phe 650 , and tyr 636 identification of this binding site provides a useful target for the screening of mmp inhibitors and for prognosis and treatment of diseases in which mmps are implicated . compounds which are candidate mmp inhibitors can be structured to competitively inhibit cell surface activation .