MscL打开的不对称性被分子动力学模拟所揭示
Olga N Rogacheva1, Wojciech Kopec1,2
1Computational Biomolecular Dynamics Group, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, Göttingen 37077, Germany.
Journal of chemical information and modeling
|June 5, 2025
概括
突变细菌机械敏感通道 MscL (L17A,V21A) 在压力下过渡到中间开放状态 (S1). 这项研究揭示了关键的分子事件和控制 MscL 门的能量景观,有助于阐明野生类型通道机制.
科学领域:
- 生物物理学的生物物理.
- 分子生物学分子生物学
- 结构生物学 结构生物学
背景情况:
- 细菌机械敏感通道MscL (MscL) 通过释放细胞流,在透应激下对细胞生存至关重要.
- 特定的突变,如L17A和V21A,降低了MscL激活所需的张力,为研究关门机制提供了一个模型.
- 了解 MscL 门对于破译细胞机械传导通路至关重要.
研究的目的:
- 通过全原子分子动力学模拟来研究 MscL 的 L17A,V21A 双突变的封闭机制.
- 描述在膜张力下的 MscL 的中间状态和形状转变.
- 开发一个反应坐标和自由能的MscL关闭到中间状态的过渡.
主要方法:
- 在30mN/m的膜张力下对MscL L17A,V21A双变异体进行全原子分子动力学模拟.
- 提交者分析和非线性回归来定义一个反应坐标的门过渡.
- 雨采样用于计算沿反应坐标的自由能量概况.
主要成果:
- 封闭的MscL L17A,V21A突变体采用了类似漏斗的形状,并顺序过渡到不对称状态 (S1,S2等). ) 的情况.
- S1状态表现出类似于*Methanosarcina acetivorans* MscL扩展状态的特征,电导率降低.
- 过渡过程中的关键事件包括链间接触的破坏,脂质结合口袋的脱脂和张力传感器的接触.
结论:
- 在紧张状态下,S1状态在热力学上是有利的,与封闭状态相比,自由能量约为5kJ/mol.
- 过渡到S1状态的自由能量障碍约为10kJ/mol,与估计的133 ± 13 ns的过渡时间一致.
- 开发的计算方法和研究结果提供了对野生类型 MscL 的关门机制的见解.
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