醇类有机溶剂对木瓜蛋白酶催化活性的影响机理

Effect on Catalytic Activity and Conformation of Papain with Four Kinds of Organic Solvent

DOI：10.3969/j.issn.1673-1689.2014.10.017

中文关键词: 木瓜蛋白酶 有机溶剂 酶活力 动力学 构象

英文关键词: papain,organic solvent,enzyme activity,kinetics,conformation

基金项目:

摘要点击次数: 251

全文下载次数: 403

中文摘要:

为了探索木瓜蛋白酶在有机溶剂中的催化机理和活力变化，为其工业应用打下基础，研究了在4种不同有机溶剂极性系数的醇类单相共溶体系中，木瓜蛋白酶水解酪蛋白的催化活性及木瓜蛋白酶构象的变化。结果表明：木瓜蛋白酶在体积分数15%丙二醇和体积分数8%正丙醇的溶液中水解酪蛋白的活性分别上升20.1%和17.8%，在乙二醇和丙三醇体系中则酶活力显著下降。动力学测定表明，木瓜蛋白酶在4种有机介质中水解酪蛋白的米氏常数Km与Vmax均明显下降。差示光谱和荧光发射光谱表明，体积分数40%丙三醇可使木瓜蛋白酶含有Trp残基区域的空间结构趋向更紧密，而在体积分数15%丙二醇和体积分数10%乙二醇体系中，无规则卷曲或者β-折叠增加的区域很少包含Trp残基。

英文摘要:

The alterations of papain activity and conformation were studied in four kinds of organic solvent，which are propanediol，glycerol，propanol and ethanediol. The result showed that the papain activity increased 20.1% in 15% propanediol，increased 17.8% in 8% propanol and decreased obviously in glycerol and ethanediol. The value of Km and Vmax was declined when treated with four kinds of organic solvent. Ultraviolet difference spectra and Fluorescence emission spectra showed that the secondary structure of papain altered in four kinds of organic solvent. The papain structure containning Trp residue was in a stronger non-polar environment in 40% glycerol，while the papain structure where coil and sheet increase contains little Trp residue in 15% propanediol and 10% ethanediol.

查看全文 查看/发表评论 下载PDF阅读器