吐温80-(NH_4)_2SO_4-H_2O液固萃取体系纯化苹果酸脱氢酶(英文)

Purification of Malic Dehydrogenase by Using Liquid-Solid Extraction System of Tween 80-(NH_4)_2SO_4-H_2O

在（NH4）SO4存在的条件下,吐温80的水溶液能够形成聚合物固相和盐水相,带电荷的水溶性物质或极性物质可被萃入聚合物固相。依据表面电荷或者分子量的差别,酶、蛋白质或其它生物活性物质可选择性的被聚合物固相所萃取。本文研究了吐温80的浓度,盐的浓度和PH值对苹果酸脱氨酶（MDH）和牛血清白蛋白（BSA）萃取率的影响,实验结果表明：选择适当的PH值、吐温80浓度和盐浓度,酶可与蛋白质分离,进而从猪心粗提液中纯化MDH,纯化倍数达到2.03。总酶活收得率88.5％。

The aqueous solution of Tween 80 forms polymeric solid phase and salt aqueous phase in the presence of (NH4):SO4. Some water-soluble materials with charge or polar materials can be transferred into the polymeric solld phase.Owing to the differences in surface charge and molecular weight、 enzyme、 protein and other materials with biological activities can be extracted selective1y by polymeric solid phase. In this paper, effects of Tween 8o concentration, salt concentration and pH on extraction efficiency of malic dehydrogenase (MDH) and BSA(bovine serum albumin) have been studied. The distribution of MDH in rough extract of pork heart between the two phases has also been investigated. The results showed that under suitable pH, the appropriate Tween 80 and salt concentration, the enzyme can be separated from protein so as to purify MDH from rough extract of pork heart. The purification fold is 2. 03. The average recovery of total emzyme activity is 88. 5%.