Soy Isoflavone Glycoside Hydrolase Purification And Characterization

A high active soybean isoflavone glucoside hydrolase producing mould strain was isolated from spirit qu. The purification and properties of the isoflavone-glucosidase were studied. The enzyme solution is purified by 11 folds and a yield of 10.9% by (NH₄)₂SO₄ precipitation and DEAE-cellulose DE-52 ion exchange chromatography. The optimum condition for the enzymic reaction is 50℃, pH 5.0. Stability ranges of pH was pH 5.0-7.0. It was stable at less than 60℃. Co²⁺, Ca²⁺ and Zn²⁺ have positive effect on the Isoflavone-glucosidase activity. Ag⁺ and Cu²⁺ inhabited enzyme activity. The molecular weight of the enzyme measured by SDS-PAGE is 53kDa.The enzyme is different from the ringinal-β-glycosidase(EC3.2.1.21) on hydrolytic characteristic and the pI 为 3.2, Km 为 12.89 mmol/L。...