离子型多孔聚苯乙烯固定化糖化酶

The Immobilization of Glucoamylase on Porous Ionic Polystyrene Beads

用离子型多孔聚苯乙烯固定化了糖化酶。研究了制孔剂比例对载体孔径的影响。用麦芽糖做底物,三乙醇胺基聚苯乙烯载体使固定化糖化酶的最适pH向左移动约2个pH单位;磺酸基苯胺基聚苯乙烯载体使固定化糖化酶最适pH向右移动2个单位。固定化酶最适pH的移动值随缓冲液浓度的增加而减少。用可溶性淀粉为底物时固定化糖化酶的pH—活力曲线变宽。用dextrin作底物,天然糖化酶的Km为3.47×10^(-3)mol/L,固定化糖化酶的素质K_m为4.17×10^(-3)mol/L,表现K_m(app)为1.11×10^(-2)mol/L。延长重氮化反应时间,得到2000ug^(-1)干胶的高活力固定化糖化酶。

Glucoamylase was immobilized on porous polystyrene beads with different ionic groups. The effects of these ionic groups, different substrates and buffer concentrations on pH profile of immobilized glucoamylase (IGA) were studied. Linewe-aver-Burk curves of the IGA and GA were obtained by using dextrin as substrate. The Km of the natural GA was 3.47×10-3mol/L, the intrinsic Km of the IGA was 4.17×10-3mol/L and the apparent Km of the IGA was 1.11×10-2mol/L. By prolonging the coupling time of diazol-protein, a high activity IGA of 2000 u/g dry gel was obtained.