醇脱氢酶在反胶束溶液中的催化动力学性质

Enzymatic Kinetics Characterizations of Immobilized Alcohol Dehydrogenase in Reversed Micelle

以十六烷基三甲基溴化铵(CTAB)-辛烷-己醇反胶束体系对醇脱氢酶(ADH)进行固定化,考察了含水量、酶液pH值、CTAB和己醇浓度对ADH固定化的影响。对游离酶和固定化酶的催化动力学性质研究表明,酶促反应的最适pH值分别为8.2和8.8,最适温度分别是31和20℃,对乙醇的米氏常数Km分别为12和7.4 mmol/L。在30℃时,游离酶存放150 min后失活90%,固定化酶失活50%,表明反胶束固定化ADH有较好的热稳定性。

The immobilization of alcohol dehydrogenase（ADH） with cetyl trimethyl ammonium bromide（CTAB）-octane-hexanol reversed micelle system was performed.The effects of w0（/）,pH value in enzyme solution,concentrations of CTAB and hexanol on the immobilization of ADH were studied.The result on the kinetic characterizations of the free and immobilized enzyme indicates that optimum pH values for the enzymatic reactions were 8.2 and 8.8,the optimum temperatures were 31 ℃ and 20 ℃,respectively.The Km values for alcohol were 12 mmol/L and 7.4 mmol/L,respectively.When the enzyme was deposited for 150 min at 30 ℃,the activities were lost by 90% and 50% for the free and the immobilized enzymes respectively,indicating that the immobilized ADH in reversed micelle has a better thermal stability.