辣根过氧化物酶在一种新型有机介质中的催化反应

选择合适的酶反应介质体系,是酶应用于有机合成的一个重要环节。利用适宜分子量的聚乙二醇（ＰＥＧ）可以将辣根过氧化物酶（ＨＲＰ）分散在甲苯中,摸索了ＨＲＰ在聚乙二醇（ＰＥＧ）－甲苯互溶体系反应的适宜条件,即ＰＥＧ／甲苯的比例、含水量、ｐＨ值、底物浓度等对酶活性影响,结果发现ＰＥＧ含量越低,含水量越高,酶的活力越高;酶在此体系中的最适ｐＨ值为７．０,最适过氧化氢浓度为２０ｍｍｏｌ／Ｌ,愈创木酚的浓度为０

A Novel Reaction Media for Horseradish Peroxidase (HRP) Catalysis in Organic Solvents

It is important to select favorable reaction media for use of enzymes in organic synthesis. In the presence of PEG with a certain molecular weight, toluene was able to dissolve horseradish peroxidase and the latter maintained a high activity. The HRP reaction conditions, such as ratio of PEG/toluene, water content, pH, and substrate concentration were investigated. It was found that the activity of HRP increased when PEG concentration was low and water content was high. In such a system, the enzyme functioned best at pH 7.0, the concentration of H 2O 2 and guaiacol being 20 mmol/L and 0.1 mol/L respectively. Under the same condition, no activity was detected in the PEG /ethanol and PEG /dioxane systems. However in PEG/toluene system, HRP maintained a higher activity and the activity was ten fold more than that in toluene alone.