灰绿青霉阿魏酸酯酶的分离纯化和酶学性质研究

摘要

Objective] The aim was to study purification and enzymatic properties of feruloyl esterase in the culture solution of Penicillium glau-cum XGY36.[Method] The feruloyl esterase was obtained in the culture solution of Penicillium glaucum XGY36 and was purified to be homoge-neous by the steps of ammonium sulfate precipitation,DEAE-cellulose DE52 chromatographies,and Sephadex G-75 chromatography.The enzyme protein with high purity was obtained,enzymatic properties were studied.[Result] Purification of about 6.54 fold was achieved with an overall yield of 59.7%.The molecular weight of purified feruloyl esterase was estimated to be about 36.5 ku by SDS-PAGE.The optimum temperature and pH of the enzyme activity were 50 ℃and 5.0,respectively in catalytic reaction of ethyl ferulate.The enzyme activity was stable under 60 ℃, and with pH range of 3.0-7.0.The activity of feruloyl esterase was highly enhanced by Zn2 +,Mg2 +and Ca2 +,whereas it was strongly inhibited by the metal ions Pb2 +,Hg2 +and Ag +,while Na +,K +,Mn2 +,Cu2 +and Fe2 +had no strong effect on feruloyl esterase activity.[Conclusion] Fer-uloyl esterase has potential applied value and fit to apply in the fields of food,medicine and biology etc..%[目的]研究青霉（Penicillium glaucum）XGY36胞外产阿魏酸酯酶的纯化和酶学性质。[方法]菌株胞外产酶发酵液经硫酸铵沉淀、DEAE－cellulose DE52离子交换柱层析、Sephadex－G75分子筛层析进行纯化，得到纯度较高的酶蛋白，并对其酶学性质进行研究。[结果]从菌株发酵液中分离纯化到电泳纯的阿魏酸酯酶，纯化倍数6．54，酶活性回收59．7％。阿魏酸酯酶经SDS－PAGE获得1个条带，其表观分子量为36．5 ku。催化底物阿魏酸乙酯的最适反应温度为50℃，最适pH为5．0。阿魏酸酯酶在60℃以下和pH 3．0～7．0范围内稳定。金属离子 Zn2＋、Mg2＋、Ca2＋对酶有明显的激活作用，而 Pb2＋、Hg2＋和 Ag ＋对阿魏酸酯酶有强烈的抑制作用，Na ＋、K ＋、Mn2＋、Cu2＋和Fe2＋对酶活的影响不大。[结论]青霉阿魏酸酯酶具有潜在的应用价值，适合应用于食品、医药及生物等领域。