壳聚糖固定化胰蛋白酶研究

Study on Chitosan-immobilized Trypsin

以自制的壳聚糖为载体,以戊二醛为交联剂,制备了壳聚糖固定化胰蛋白酶。经测定该酶活性回收率达到72.7%,操作半衰期为12 d,表观米氏常数为5.88 mg/ml,最适pH值为8.0,最适温度为40℃;与游离胰蛋白酶相比,酶的耐热性和操作半衰期有明显提高,但表观米氏常数也略有增大。

Immobilized trypsin was prepared with the Chitosan as matrix and glutaraldehyde as cross-linking agent. The recovery of enzyme activity reached 72.7% after the ircanobilization. As compared to that of the free trypsin, the stability and heat-resistance of trypsin was moderately improved after the immobilization,which reached 12 days and 40 - 50℃, respectively. The significant variation was not found between the suitable pH of free and immobilized trypsin, and the both reached the maxinmm activity at pH =8.0. The Km value of the immobillized enzyme （5.88 mg/ml） showed a little increase as compared to that of the free trypsin （4.36 mg/ml） ,which indicated the affinity between the enzyme and the substrate was decreased after the immobilization.