ISOLATION OF SOYBEAN LIPOXIDASE BY ISOELECTRIC FOCUSING

Soybean lipoxidase (oxygenase (1.99.2.1)) was isolated from soybean whey proteins by isoelectric focusing in the pH region between 5 and 8. The enzyme exhibits its isoelectric point at pH 5.65. The isolated soybean lipoxidase was found to be homogeneous by disc electrofocusing, disc eleotrophoresis, and immunoelectrophoresis using several anti-soybean whey protein sera. A 230-fold concentration of the euzyme was obtained in respect to the dry solids of the original water extract. The lipoxidase activity of the homogeneous enzyme was of the order of 110,000 units/mg protein. © 1969.