诱导蛋白酶K去折叠过程的热力学研究
Study on thermodynamics of the induced unfolding process of proteinase K
作者：张奇兵;那馨竹;尹宗宁;
Author：
收稿日期： 年卷（期）页码：2013,28(06):-567-570
期刊名称：华西药学杂志
Journal Name：WEST CHINA JOURNAL OF PHARMACEUTICAL SCIENCES
关键字：蛋白酶K;荧光光谱;热力学参数
Key words：
基金项目：国家自然科学基金资助项目(批准号:30973659)
中文摘要
目的研究诱导蛋白酶K的去折叠过程,尝试阐明构象与酶活力的关系。方法蛋白酶K经过盐酸胍处理后,以变性酪蛋白为底物测定酶活力,采用荧光光谱法研究酶分子的构象变化,计算相关的热力学参数。结果随着盐酸胍浓度升高,蛋白酶K的酶活力和荧光强度降低,峰位红移,碘化钾对酶分子的内源性荧光猝灭作用增强,去折叠分数增大;蛋白酶K的热变性中点温度和最大稳定温度降低;去折叠过程的熵变大于0。结论蛋白酶K对低浓度的盐酸胍较为稳定,3.5 mol·L-1为盐酸胍诱导蛋白酶K变性的临界浓度;空间构象的稳定性是维持酶活力的基础;蛋白酶K的热稳定性随盐酸胍浓度增大而降低;盐酸胍诱导蛋白酶K的去折叠过程是熵驱动的。
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