双醛氧化纤维素固定胰蛋白酶性质研究

Study on immobilization of trypsin by dialdehyde oxycellulose and enzymatic properties

研究固定化酶载体-氧化型纤维素条件优化,并用此载体固定胰蛋白酶。结果表明,当氧化剂高碘酸钠浓度为0.5 mol.L-1,氧化环境pH 2,氧化时间为3.5 h,反应温度为35℃时,氧化纤维素醛基质量分数可到达74.06%。以此为载体固定胰蛋白酶,可得到固定化胰蛋白酶最适温度为60℃,最适pH 9.0,固定化酶比自由酶热稳定性提高。在最适条件下,固定酶可重复使用5次以上,之后活性才有所下降,将固定化酶置于4℃冷藏保存,5 d后活性保持在90%,固定化酶表现出较高使用和贮藏稳定性,为胰蛋白酶广泛应用奠定基础。

Sodium periodate were used to conduct the epoxidation and dialdehyde oxidation ofcellulose for preparing epoxidized dialdehyde oxycellulose. The prepared epoxidized dialdehyde oxycel- lulose was used as the carrier to immobilize trypsin. The results showed that when the oxidant sodium periodate the concentration of 0.5 mol. L1, at pH 2.0, after 3.5 h at 35℃, the oxidation was 74.06%. Immobilization conditions and the enzymatic properties of immobilized trypsin were investigated. The results showed that： the immobilized trypsin optimum temperature of 60 ℃ and the optimum pH value of 9.0. The immobilized enzyme to improve the thermal stability of the free enzyme. Under optimum conditions, the immobilized enzyme could be reused more than 5 times the activity began to decline, the immobilized enzyme showed a higher use and storage stability of the immobilized enzyme stored at 4 ℃ for 5 d after the activity maintained at 90%.