Some Properties of Protease from Bacillus R-4 Which Lyses Rhizopus Cell Wall

A strain of Bacillus sp. (Bacillus R-4) produces a protease and a chitosanase which have the ability of lysing Rhizopus cell wall. Some enzymatic properties of the protease purified to a homogeneous state were examined.

The molecular weight of the enzyme was estimated as 19,000 and the isoelectric point as pH 8.65. The protease appeared to have a relative wide range of substrate specificity, hydrolyzing various proteins, such as gelatin, hemoglobin and protamine, and synthetic peptides, such as Z-Gly-Try-NH₂, Z-Gly-Ala-NH₂, Z-Ala-Leu-NH₂ and Z-Gly-Leu-NH₂. The activity lost by EDTA and by Hg²⁺ was restored by Zn²⁺ and reduced glutathione, respectively.