性酸酶单酶和酶反应:比较的过渡状态分析
Jesse G Zalatan1, Daniel Herschlag
1Department of Chemistry, Stanford University, California 94305, USA.
Journal of the American Chemical Society
|January 26, 2006
概括
大肠杆菌的性酸酶 (AP) 不会改变酸二水解的过渡状态. 相反,AP承认并稳定了类似解决方案的过渡状态,帮助其乱伦活动的演变.
科学领域:
- 生物化学 生物化学
- 酶动力学 酶动力学
- 蛋白质工程是一种蛋白质工程.
背景情况:
- 酶催化转移反应通常涉及与溶液中的过渡状态不同的过渡状态.
- 大肠杆菌的性酸酶 (AP) 主要通过类似于溶液的解离性过渡状态来化单.
- AP还表现出固酶活性,这通常涉及到溶液中更具关联性的过渡状态.
研究的目的:
- 调查AP活性位点是否会改变酸二水解的过渡状态.
- 为了确定AP是否稳定了随性活动的解决方案类过渡状态.
主要方法:
- 替代甲基酸二的非酶和AP催化水解的动态分析.
- 测量β (lg) 值以探测过渡状态结构.
主要成果:
- 发现AP催化酸二水解的过渡状态与溶液状态无法区分.
- AP似乎不会显著改变二水解的过渡状态结构.
结论:
- AP通过识别和稳定类似于水溶液中的过渡状态来催化醇转移.
- AP活性部位识别多种过渡状态的能力可能有助于其杂乱的酶性活动的演变.
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