Rat dipeptidyl peptidase IV (DPP IV) exhibits endopeptidase activity with specificity for denatured fibrillar collagens

Dipeptidyl peptidase IV (DPP IV, CD 26) is an integral membrane serine protease exhibiting a well characterized esopeptidase activity. The present study shows that DPP IV also possesses a novel gelatinase activity and therefore endopeptidase activity, which was directly demonstrated by gelatin zymography. Protease inhibitor profile analysis showed that the endo-and esopeptidase activities of DPP IV share a common active site. Substrate specificity was detected for denatured collagen types I, II, III and V suggesting that DPP IV might contribute to collagen trimming and metabolism. On the basis of these data we propose that DPP IV and the recently sequenced gelatinolytic seprase (FAP alpha) represent a new subfamily of gelatinolytic integral membrane serine proteases. (C) 1998 Federation of European Biochemical Societies.