Studies on Bacterial Protease

Some physical and chemical properties and substrate specificity were investigated of the neutral protease obtained from B. amylosacchariticus, a strain of saccharogenic a-amylase-producing Bacillus subtilis. The molecular weight and sedimentation coefficient of the pro-tease were estimated to be 33, 800 and 3.02, respectively, by ultracentrifugal analyses, and alanine was identified as an amino-terminal amino acid of the enzyme by the Sanger's method. The enzyme showed more broad specificity than the neutral protease of liquefying α-amylase-producing B. subtilis, when tested with synthetic peptides, and hippuryl-L-leucin-amide was the best substrate among 42 compounds tested. On a long incubation, the enzyme hydrolyzed several proteins in a degree of 10 to 25% as peptide bond cleavage.