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三酸盐异构酶中的循环运动不是一个简单的打开和关闭情况
Qinghua Liao1, Yashraj Kulkarni1, Ushnish Sengupta2,3
1Department of Chemistry - BMC , Uppsala University , BMC Box 576, 751 23 Uppsala , Sweden.
Journal of the American Chemical Society
|October 27, 2018
概括
酶循环运动对于催化非常重要. 三酸盐异构酶 (TIM) 循环6的灵活性,而不仅仅是开放/关闭状态,决定了有效的基质加工和催化活性.
科学领域:
- 生物化学
- 酵素学
- 结构生物学
背景情况:
- 酶催化依赖于形状变化.
- 三酸盐异构酶 (TIM) 循环的动态是其功能的关键.
- 之前的模型建议简单的双状态循环运动.
研究的目的:
- 调查TIM循环6的详细结构动态.
- 了解循环灵活性在酶催化中的作用.
- 在Apo和基质结合状态下分析循环运动.
主要方法:
- 广泛的分子动力学模拟 (常规和增强的采样).
- 分析了Saccharomyces cerevisiae TIM的五个晶体结构.
- 用于反应步骤分析的实证价值键模拟.
主要成果:
- TIM环6具有显著的灵活性,并采用多种形状.
- 与完全封闭循环的轻微偏差消除了催化活性.
- 完整的循环闭合对于有效的基质催化是必不可少的.
结论:
- 时间循环的运动是复杂的, 不是一个简单的两种状态的过渡.
- 环的灵活性和精确的形状对于高的催化效率至关重要.
- 了解这些动态可以了解酶的机制和设计.
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