Subtilisin Amylosacchariticus I. PHYSICOCHEMICAL CHARACTERIZATION

Abstract The diisopropylphosphoryl derivative of subtilisin Amylosacchariticus has an isoelectric point of pH 7.80 and a sedimentation coefficient (s020,w) of 2.71 S. The molecular weight for native and denatured protein, determined by sedimentation equilibrium, is 27,500. The amino acid composition is intermediate between those of subtilisins BPN' and Carlsberg. NH2-and COOH-terminal sequences are similar to those of subtilisin BPN'. The reactivity of subtilisin Amylosacchariticus with the specific inhibitor benzyloxycarbonyl-l-phenylalanylbromomethane is about an order of magnitude less than that of subtilisins BPN' and Carlsberg.