对高电场的Beta-Barrel通道反应:功能性隔离还是可逆变性?
Ekaterina M Nestorovich1,2, Sergey M Bezrukov2
1Department of Biology, The Catholic University of America, Washington, DC 20064, USA.
International journal of molecular sciences
|December 9, 2023
概括
强大的电场可能可逆地变质,不是门,细菌外膜通道OmpF. 这种蛋白质变性化,而不是功能性关门,解释了模型膜中通道的关闭和重新开放.
科学领域:
- 生物物理学的生物物理.
- 膜蛋白结构和功能 膜蛋白结构和功能
- 蛋白质的静电学 蛋白质的静电学
背景情况:
- 离子通道调节细胞活动,而电压通道对刺激细胞至关重要.
- 与α螺旋通道不同,β-桶通道的选择性较低,与细胞刺激性没有直接关系.
- 这些β-桶通道可以在强烈的电场下关闭,并在移除电场后重新打开,保留事件的记忆.
研究的目的:
- 调查电压诱导的β-桶通道的关闭是否是功能性关门或可逆蛋白质变性.
- 在平面脂质双层中分析细菌外膜通道OmpF的闭开过程.
主要方法:
- 将细菌外膜通道OmpF重构成平面脂质双层.
- 应用高电场 (每米超过2000万伏) 来诱导通道关闭.
- 分析通道关闭-开启特征,包括电压极性响应,多个关闭状态,通道聚类,门内存和霍夫迈斯特效应.
主要成果:
- 观察到的OmpF关闭的特征与可逆蛋白质变质化相一致,而不是功能性关门.
- 对两个极性的电压几乎对称的反应表明变性.
- 多个封闭状态和长期门内存进一步支持变性假设.
- 对闭合动力学的霍夫迈斯特效应为场诱导的结构变化提供了额外的证据.
结论:
- 像OmpF这样的β-桶通道的电压诱导的关闭可能是一种由电场引起的可逆蛋白质变质的形式.
- 这种现象可能是神经和肌肉细胞中复杂的电压受控通道的进化前体.
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