labeled with 3 h dfp and their molecular identity may be visualized on sds gels pineiro sanchez et al 1997 by incubating the seprase dppiv complex with 3 h dfp in the presence of their peptide substrates or inhibitors the protease inhibition is quantified seprase and the seprase dppiv complex were purified from 10 11 lox human malignant melanoma cells or mda mb 436 human breast carcinoma cells that express seprase and the seprase dppiv complex respectively cell lysates are subjected to two steps of enrichment triton x 114 detergent phase partitioning and wga chromatography and they are stored at u2212 80 u00b0 c purified seprase is prepared immediately prior to experimentation by immunoprecipitation of lox wga binding proteins with micro magnetic beads about 50 nm miltenyi biotec using mab d28 or d8 the seprase dppiv complex is purified from mda mb 436 wga proteins with either anti seprase or anti dppiv monoclonal antibodies purified seprase and the seprase dppiv complexes are used to define inhibitor specificity and substrate specificity of the enzymes substrate specificity of the seprase dppiv complex that was purified by monoclonal antibodies collagen substrate specificity of the seprase dppiv complex was determined by incubating fluorescently labeled type i collagen with isolated seprase dppiv or seprase dppiv complex in the presence of simp inhibitors pmsf inhibits seprase.