山梨醇脱氢酶性质研究

Study on Characteristics of Sorbitol Dehydrogenase

目的:山梨醇脱氢酶具有不完全氧化多种羟基化合物的特性,在工业中已广泛应用。该文研究该酶的酶学性质。方法:利用单因素实验对山梨醇脱氢酶的储藏稳定性和操作稳定性、反应液的pH和反应温度对酶活力的影响进行了研究,并进行了反应动力学研究。结果:反应液的pH值为5.5、反应温度为28℃时,酶活力最高;单批次反应过程中,酶基本没有失活。底物耗尽时,连续进行两次补加相同量的底物,酶活力有较小的降低。第一次重复时,酶活力有较小的降低;在第二次重复使用时,丧失40%的活力;山梨醇脱氢酶的底物特异性常数Ks为51 mmol/L,单位生物量的山梨醇脱氢酶最大活力Umax为1.7U/mg干细胞。结论:山梨醇脱氢酶的稳定性较高。

Objective： Sorbitol dehydrogenase has the characteristic of non - complete oxidating polyols, and it has been applied in industry extensively. Enzymatic characteristics were studied in the article. Method： Storing and using stability, pH and temperature of reactive liquid and kinetic of sorbitol dehydrogenase were studied by single experiment. Result： When pH was 5.5 and temperature was 28, enzyme activi- ty was the hightest. In the course of usage, enzyme activity almost did not fall. When substrates were used up and the same amount of sub- strates were supplied continuously, enzyme activity lost little. When it was used again, enzyme activity lost little. When it was used in the third time, enzyme activity lost 40%. Ks and Umax was 51 mmol/L and 1.7U/mg dry cell respectively. Conclusion：Stabilities of sorbitol dehydrogenase were high.