通过310K的分子动力学模拟,达到冷EM重建的全部潜力:举例来说,阿克丝
Sahithya Sridharan Iyer1, Kristina M Herman1, Yihang Wang1
1Department of Chemistry, Chicago Center for Theoretical Chemistry, Institute for Biophysical Dynamics, and James Franck Institute, The University of Chicago, Chicago, IL.
bioRxiv : the preprint server for biology
|August 20, 2025
概括
低温电子显微镜 (cryo-EM) 揭示了静态蛋白质结构,但分子动力学 (MD) 模拟显示,在生理温度下,活性纤维 (蛋白质复合体) 采用不同的构造. 这些模拟提供了有关ATP水解和蛋白质相互作用的见解.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 计算生物学 计算生物学
背景情况:
- 低温电子显微镜 (cryo-EM) 提供了像actin纤维一样的蛋白质复合体的高分辨率结构.
- 然而,冷EM冷可能无法在生理温度下捕获本地形状.
研究的目的:
- 通过全原子分子动力学 (MD) 模拟,研究在生理温度下的酸丝形状和动力学.
- 将模拟结果与冷EM数据进行比较,并解释功能机制.
主要方法:
- 全原子分子动力学模拟是从actin纤维的冷EM重建开始的.
- 分析子单元形状,活性位点动态和约束位点在310K的可访问性.
主要成果:
- 在310 K的温度下,ADP-actin纤维呈现出更多的扭曲子单元和改变的旋转,与冷-EM结构相比.
- 用于ATP水解的关键残留物和水分子在生理温度下很少处于最佳位置.
- ADP-Pi-actin细丝显示了酸盐释放的开放门,短暂的开放揭示了cofilin和phalloidin的结合点.
结论:
- 在冷EM中使用的冷温度可能会导致非生理学性的actin导线形状.
- 模拟MD对于了解蛋白质动力学和在生理温度下的功能至关重要.
- 这些发现强调了在结构生物学研究中考虑温度影响的重要性.
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