Protease S is a serine endoprotease with broad specificity that will digest native and denatured proteins. Cleavage occurs mainly on the carboxy side of peptide bonds. The optimal temperature range is 85 to 95°C and the optimal pH range is 6.0 to 8.0. Protease S is inhibited by PMSF. Thermostable serine protease with broad specificity for native and denatured proteins.http://www.creative-enzymes.com/product/Protease-S-From-Pyrococcus-Furiosus-Recombinant_1600.html