Serine protease. Degrades fibrinogen. Strongly inhibited by pMSF, chymotrypsin and SDS. Inhibited by the trypsin inhibitors Tos-Phe-CH2Cl, Tos-Lys-CH2Cl and SBTI, and by bivalent cations. Slightly inhibited by the elastitinal and metal chelators EDTA and EGTA, by ethanol and by non-ionic detergents. Not inhibited by alkylating agents, reducing agents, pepstatin, o-phenanthroline, leupeptin, E-64, bestatin, DMSO and methanol. Optimum pH is 9.0. 20% of maximum activity is seen at pH 5.0. Inactive below pH 5.0 and above pH 11.0, inactivation by acidic pH is reversible. Optimum temperature is 37-50 degrees Celsius. 49% of maximum activity is seen at 60 degrees Celsius, no activity is seen at 70 degrees Celsius. Thermolabile, a significant decrease in activity is seen after incubation at temperatures above 42 degrees Celsius for 20 min. Monomer. Not glycosylated. Belongs to the peptidase S8 family.