Alkaline serine protease that cleaves various substrates, including N-succinyl-Ala-Ala-Pro-Phe-pNA, N-succinyl-Ala-Ala-Pro-MetpNA, oxidized insulin B chain, casein, hemoglobin and scleroproteins, such as keratin, alpha-keratin and elastin. Binds 2 calcium ions per subunit. Activity is inhibited by phenylmethylsulfonyl fluoride and chymostatin. Optimum pH is 12.3. Optimum temperature is 55 degrees Celsius. CaC1(2) markedly shifts the optimum temperature to 70 degrees Celsius. Monomer. Belongs to the peptidase S8 family.