Abstract
A carboxyl proteinase was purified from rice koji of Aspergillus kawachii to a homogeneous state on polyacrylamide gel electrophoresis. The molecular weight and isoelectric point of the enzyme were 35, 000 and 3.9, respectively. The enzyme was most active between pH 2.8 and 3.4 with hemoglobin as substrate, and stable in the pH range of 2.2-6.4. The optimum temperature of the enzyme reaction was at 50°C. The serine content was highest and no methionine was found in the enzyme. The enzyme was inhibited by typical inhibitors for carboxyl proteinases such as DAN, EPNP, and SPI.
