Characterization of the Ecochemical in Kidney Beans Which Inhibits the Larval Growth of the Azuki Bean Weevil

Abstract

An inhibitor of larval growth of the azuki bean weevil was isolated from kidney beans. The growth inhibitor was a glycosylprotein with a molecular weight of ca. 48, 000 and an isoelectric point of 4.46, which had several subunits and moieties sensitive or insensitive to endo-N-acetyl-, β-D-glucosaminidase H. Its carbohydrate content was 15.2%, based on 20 mannose, 1 fucose, 2 xylose and 15 N-Ac-glucosamine residues per one mole (8.5% by the phenol-sulfuric acid method). It inhibited α-amylases of animal origins, but not those of plant and microbial origins. It had no trypsin inhibitory and lectin activities. Both carbohydrate and native protein moieties seemed to be required for growth and α-amylase inhibition. The overall results indicated that the growth inhibitor was identical with or similar to the α-amylase inhibitors previously isolated from kidney beans.