Serine protease with a broad substrate specificity. Hydrolysis of proteins with broad specificity for peptide bonds, and a preference for a large uncharged residue in P1. Hydrolyzes peptide amides. Resistant to treatment with 5% SDS, 8 M urea, 10% Triton X-100 or 10% Tween-20. Fully active although less stable in the presence of 10 mM EDTA. Activity not affected by the absence or presence of 10 mM CaCl(2). Unstable in the presence of 2 M or over GdnHCl and loses 35% and 99% of its activity upon incubation with 2 and 4 M GdnHCl, respectively, for 1 hour at 55 degrees Celsius. Nearly fully loses activity upon incubation at pH 2.0. kcat is 1.6 sec(-1) for N-succinyl-Ala-Ala-Pro-Phe-p-nitroanilide at 20 degrees Celsius and pH 7.5(PubMed:20100702). kcat is 25 sec(-1) for N-succinyl-Ala-Ala-Pro-Phe-p-nitroanilide at 80 degrees Celsius and pH 7.5(PubMed:20100702). High activity at a wide pH range between 7.0-11.5 at 20 degrees Celsius and pH 7.5. It is not fully stable at pH 6 or under and at pH 12 or over. It loses over 85% of its activity at pH 3 or under and at pH 13. Optimum temperature is about 100 degrees Celsius. Highly thermostable. Stable at 80 degrees Celsius for at least 3 hours. Half-life at 100 degrees Celsius is 100 minutes and at 90 degrees Celsius more than 3 hours. Monomer. The C-terminal calcium-binding beta-jelly roll domain (445-562) of the mature domain is not required for folding or activity, but it is required for the hyperstabilization of the protein and possibly for its adaptation to high-temperature environment. Has potential for application in biotechnology fields due to its high resistance to heat, denaturants, detergents and chelating agents. Belongs to the peptidase S8 family.