OCCURRENCE OF A LATENT SERINE-PROTEASE IN THE FOLLICULAR-FLUID OF PORCINE OVARY

Porcine ovary folliclular fluid contains a latent form of a protease w hich is activatable with trypsin. The active enzyme hydrolyzed peptide 4-methylcoumaryl-7-amide (MCA) substrates with a preference for the A rg-MCA bond. The enzyme was strongly inhibited by diisopropylfluoropho sphate, aprotinin, leupeptin and antipain, but not by soybean trypsin inhibitor. The apparent molecular weight of the enzyme was approximate ly 630,000 as estimated by gel filtration. No significant difference i n molecular size was seen between the inactive precursor and trypsin-a ctivated The results suggest that the present enzyme is a novel type o f serine protease.