|Budget Amount *help
¥1,900,000 (Direct Cost : ¥1,900,000)
Fiscal Year 1993 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1992 : ¥1,300,000 (Direct Cost : ¥1,300,000)
Porcine ovary was found to contain enzyme activities hydrolyzing peptide 4-methylcoumaryl-7-amide (MCA) substrates with a preference for Arg-MCA bond. The activities were shown to be present almost exclusively in the follicular fluid and to increase several times during follicular maturation. An enzyme responsible for the activity was purified to apparent homogeneity. The purified wnzyme consists of two different polypeptide chains having Mr-45,000 and 32,000 each, associated covalently. The enzyme activity was strongly inhibited by diisopropylfluorophosphate, benzamidine, leupeptin and antipain, indicating that it is a scrine proteinase. Using synthetic peptide substrates containing MCA, the enzyme was confirmed to hydrolyze preferentially Arg-X bonds but not LyS-X bonds. The amino-terminal amino acid sequences of the 45kDa and 32kDa polypeptides as well as were highly homologous with those of the heavy and light chains, respectively, of human lpasma kallikrein and human factor XIa. Immunological analyzes and substrate specificity studies, together with other existing evidence, indicated that the enzyme is distict from the kallikrein and factor XIa.
Thus this enzyme is a movel type of serine proteinase, and we named it follipsin. Follipsin is immunohistochemically localized in follicular fluid as well as in stroma cells of porcine ovary. The results strongly suggest that follipsin originates from interstitial cells of ovarian stroma.