基于NMR的构造组合解释了OmpG通道的pH受控开放和关闭
Tiandi Zhuang1, Christina Chisholm, Min Chen
1Department of Molecular Physiology and Biological Physics and Center for Membrane Biology, University of Virginia , Charlottesville, Virginia 22903, United States.
Journal of the American Chemical Society
|September 12, 2013
概括
外膜蛋白G (OmpG) 使用pH受控的传输机制. 新的NMR方法揭示了控制OmpG通道的动态循环运动,为膜蛋白调节提供了洞察力.
科学领域:
- 结构生物学是结构生物学.
- 生物物理学的生物物理.
- 分子生物学分子生物学
背景情况:
- 来自大肠杆菌的外膜蛋白G (OmpG) 是一种单体β-桶蛋白.
- OmpG作为一种非特异性蛋白起作用,促进了寡糖的吸收.
- 之前的研究表明,基于晶体结构的pH受控孔隙机制,循环6在低pH时阻断孔隙.
研究的目的:
- 使用NMR可视化OmpG的循环6的结构动态.
- 为了计算解释pH受入孔机制的构造组合.
- 通过使用二硫化物交联和电生理学来验证这些发现.
主要方法:
- 核磁共振 (NMR) 偏磁放松增强 (PRE) 光谱.
- 构成组合的计算计算.
- 二硫化物交叉连接实验.
- 单通道电生理记录. 单通道电生理记录.
主要成果:
- NMR PRE成功地可视化了OmpG循环6的结构动态.
- 计算了符合组合,解释了OmpG通道的pH受影响的开关.
- 硫化物交叉链和电生理学验证了PRE衍生的循环对应物.
- 在pH值6.3和7.0时,还发现了额外的与膜相关的构造组合.
结论:
- OmpG通道封锁比以前假设的更有动态调节.
- 该NMR PRE方法是有效的表征在膜蛋白的功能重要构造组合.
- 这种方法可以广泛应用于其他膜蛋白.
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