Characterization of C-terminally truncated human tissue inhibitor of metalloproteinases-4 expressed in Pichia pastoris Stratmann, B Stratmann B Farr, M Farr M Tschesche, Harald Tschesche Harald The tight regulation of extracellular matrix remodeling and degradation is of great importance in physiological processes like development and morphogenesis, as well as in pathological situations like tumor invasion and metastasis. Tissue inhibitors of metalloproteinases (TIMPs) are the naturally occuring inhibitors of matrix metalloproteinases, which are involved in matrix turnover. In this report we describe the cloning of human TIMP-4 from a human adenocarcinoma and an osteosarcoma cell line and the expression of the inhibitory domain in the methylotrophic yeast Pichia pastoris. The inhibition of MMP-8, -9, -12, -13 and -14 by the N-terminal domain of TIMP-4 was analysed. Using a fluorescent MCA-peptide, K-i values for each subclass of MMPs were determined. With dissociation constants in the nanomolar range, TIMP-4 seems to be a good inhibitor for all classes of MMPs without remarkable preference for special MMPs. 382 6 987-991 987-991 WALTER DE GRUYTER & CO 2001 1