유안염석과 column chromatography 및 gel여과 등으로 비활성이 45.2U/mg가 되는 정제된 Rhizopus oryzae의 생전분 분해효소를 16.2%의 수율로 얻었다. 정제효소는 전기영동상에서 그 순도가 인정되었고 분자량은 67000, Km값은 4.082mg/ml이었다. 정제효소는 $50^{circ}C$, pH $4.0{sim}5.0$에서 잘 작용하였으며 옥수수amylose가 가장 적합한 전분이었고 옥수수 생전분에 작용한 분해산물은 거의 glucose였다.
A raw starch-digesting enzyme from Rhizopus oryzae was purified by ammonium sulfate fractionation, DEAE-sephacel column chromatography and Sephadex G-150 gel filtration. The specific activity of purified enzyme was 45.2 Ulmg protein and the yield was 16.2%. The purified enzyme was found to be homogeneous bypolyacrylamide gel electrophoresis and its molecular weight was estimated to be 67,000 by SDS-polyacrylamide gel electrophoresis, and also the enzyme had Km value of 4.082 mg/ml for raw corn starch. The optimal temperature and pH for the enzyme activity were $50^{circ}C$ and 4.0-5.0, respectively. Reaction product of raw corn starch by purified enzyme was glucose mainly.
