通道电压传感器对跨膜电位的初始响应
Werner Treptow1, Mounir Tarek, Michael L Klein
1Center for Molecular Modeling and Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
Kv1.2通道电压传感器 (VS) 在应用超极化电压时快速过渡到稳定的中间状态. 这涉及S2,S3和S4的电荷运动,由脂质相互作用稳定.
科学领域:
- 生物物理学的生物物理.
- 计算神经科学是一种神经科学.
- 结构生物学 结构生物学
背景情况:
- Kv1.2通道对神经元刺激性至关重要.
- 电压传感器 (VS) 控制道封闭,以响应膜电位.
- 了解早期的VS转换是通道功能的关键.
研究的目的:
- 为了研究高极化电压下Kv1.2通道VS的初始形状变化.
- 为了阐明VS激活期间的分子机制和电荷运动.
- 确定关键的残留物和稳定中间状态的相互作用.
主要方法:
- 完整的原子分子动力学 (MD) 模拟.
- 应用超极化跨膜 (TM) 电压.
- 对形状变化和封锁电荷的分析.
主要成果:
- VS经历了构造变化,在20 ns内达到稳定的动力中间状态 (β').
- 测量了大约2e的大门电荷.
- 在S2,S3和S4 (不包括R294,R297) 中的盐桥重新排列主要有助于门收费.
- S4残留物 (R294,R297) 和脂质头组之间的相互作用稳定了β'状态.
结论:
- 早期的电压传感器转换是快速的,涉及到特定的盐桥重组.
- 脂质-蛋白质相互作用在稳定Kv1.2电压传感器的功能状态方面发挥着至关重要的作用.
- 这项研究为通道封闭机制提供了原子层面的见解.
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