无花果蛋白酶在阴离子交换树脂上的固定化

无花果蛋白酶通过８％戊二醛活化载体，共价结合到聚苯乙烯阴离子交换树脂ＧＭ２０１上，固定化作用在ｐＨ７．７，酶浓度０．８ｍｇ／ｇ树脂，４℃下进行６ｈ。得到的固定化酶表观Ｋ_ｍ值（酪蛋白，１．１１×１０~（－４）ｍｏｌ／Ｌ）小于溶液酶Ｋ_ｍ值（１．９６×１０~（－４）ｍｏｌ／Ｌ）；固定化酶活性在ｐＨ６～８保持稳定，溶液酶最适ｐＨ为７．２；固定化酶最适温度由溶液酶的５０～６０℃移至３７℃；固定化酶２５℃保持７ｄ，重复水解酪蛋白７次后，保留８３．３％活性。固定化酶对酪蛋白水解度达４７．５％，对大豆球蛋白达１１．６％。

Studies on Immobilization of Ficin on Anion Exchange Resin GM 201

Ficin was covalently immobilized to the carrier, anion exchange resin GM201, by activating the carrier with glutaraldehyde. The immobilization was performed at PH7.7, 4℃,for 6h using enzyme concentration 0. 8 mg/g resin. The resulting immobilized enzyme has an apparent Km of 1.11×10￣(-4) mol/L for action on casein as compared to 1.96×10￣(-4) mol/L by soluble enzyme. The optimal pH range of immobilized ficin became much broader, changing from PH7.2 for soluble enzyme to pH6￣8, at which the activity of immobilized enzyme remained stable. The optimal temperture changed from 50￣60℃ for soluble enzyme to 37℃ for the immobilized enzyme. After it was stored at 25℃ for 7 days, the immobilized ficin retained approximately 83.3% of its original activity after 7 rounds of reaction using casein as substrate. The degree of hydrolysis was 47.5% for casein and 11.6% for soybean protein.