抄録
1) The protease from the cultural filtrate of Ps. myxogenes sp. was purified and crystal-lized in a needle-like form with a high yield (0.5-0.9g of the once recrystallized ones from 5 liters of broth).
2) The crystalline protease was found to be homogeneous in nature, with electrophoresis at pH 8.07, and the i. e. p. was pH 5.5-6.0. For ultraviolet absorption spectrum, the maximum was observed at 275mμ and the minimum at 250 mμ. The M. W. has been confirmed to be about 77, 000 by the diffusion method. It showed a typical protein reac-tion in elementary analysis or by composition of amino acids.
3) By heat-treatment, the crystalline pro-tease was found to be stable up to 50°C and was inactivated rapidly over 58°C. At 58°C the enzyme was greatly protected by metal ions such as Ca, Mg, Mn or Co, but these ions did not show any protective action over 64°C. The enzyme was found to be unstable below pH 4.0, but stable between pH 5.5 to 10.0.
4) Enzymatic action of the crystalline protease was inhibited by the heavy metal ions such as Fe+++, Fe++, Hg++, Cu++, Ag+, Pb++ or Zn++. The high concentration of HCN, cystein or phenyl-hydrazine lowered the enzymatic action, but it was not affected by the low concentration. Enzymatic activity was not altered by EDTA-treatment, there-fore, it is concluded that Ca has no relation to enzymatic activity.
