苦杏仁多酚氧化酶的分离纯化及部分特性分析

摘要

With apricot kernels as raw material,the (NH4)2SO4 fractional precipitation and Sephadex G-75 gel chromatography were employed to precipitate and purify the polyphenol oxidase from apricot kernel respectively,and the pure polyphenol oxidase was obtained after freeze drying.In addition,the relative molecular weight and denatured temperature of the purified polyphenol oxidase were also determined by the electrophoresis experiment and thermal analysis.The results showed that the purification fold of the polyphenol oxidase was 49.03 times after isolation and purification,and the relative molecular weights of its isozyme were about 21.9 kD and 23.2 kD respectively,and its denatured temperature was 60.03 ℃.The research results could provide some theoretical parameters for the control of enzymatic browning in the processing of apricot kernel.%以苦杏仁为原料,采用(NH4)2SO4分级沉淀法对苦杏仁多酚氧化酶进行初步分离后经Seph-adex G-75凝胶柱层析进一步纯化,冷冻干燥后即得苦杏仁多酚氧化酶纯品;通过凝胶电泳和热分析试验测定多酚氧化酶的相对分子质量和变性温度.结果表明:经分离纯化后苦杏仁多酚氧化酶的纯化倍数为49.03倍,该酶可能存在同工酶且相对分子质量分别约为21.9 kD和23.2 kD;苦杏仁多酚氧化酶变性温度为60.03℃.为苦杏仁加工过程中的酶促褐变控制提供部分理论参数.