通过固态NMR探测的七个跨膜螺旋蛋白 Anabaena Sensory Rhodopsin的构造动力学
Daryl B Good1, Shenlin Wang, Meaghan E Ward
1Department of Physics and ‡Biophysics Interdepartmental Group, University of Guelph , Guelph, Ontario, N1G 2W1 Canada.
Journal of the American Chemical Society
|January 29, 2014
概括
固态核磁共振 (NMR) 谱学揭示了阿纳贝纳感觉罗多普辛中受限的亚微秒运动. 在跨膜和循环区域观察到中等时间尺度运动,在纳秒到数百纳秒的范围内.
科学领域:
- 生物物理学的生物物理.
- 结构生物学 结构生物学
- 核磁共振 (NMR) 光谱学 核磁共振 (NMR) 光谱学
背景情况:
- 核磁共振 (NMR) 光谱是研究分子动力学的强大技术.
- 了解蛋白质动态对于阐明生物功能至关重要.
- 阿纳贝纳感觉罗多普辛是一种涉及环境感知的七个跨膜螺旋蛋白.
研究的目的:
- 用固态NMR测量Anabaena感官Rhodopsin中特定位置的分子运动.
- 描述蛋白质的跨膜和循环区域运动的时间尺度和性质.
主要方法:
- 固态NMR测量双极顺序参数的特定位置测量.
- 在快速神奇角度旋转条件下测量 (15) N旋转框架旋转 (R1ρ) 放松率.
- 一个简单的模型与单个指数自相关函数的应用.
- 使用3D高斯轴波动模型来分析运动.
主要成果:
- 观察到的顺序参数表明跨膜和循环区域的受限次微秒运动.
- R1ρ速率有显著的变化,这表明中间时间尺度的运动.
- 估计的主导随机运动时间尺度范围从几十到几百纳秒.
- TM螺旋体在几十纳秒的时间尺度上表现出刚性身体运动,螺旋体G接近100纳秒.
- 细胞外循环 (B-C和F-G) 显示了类似的100-200 ns的运动时间尺度.
结论:
- 阿纳巴纳感觉罗多普辛在不同地区表现出复杂的动态.
- 对于跨膜螺旋和循环,建议采用集体异构运动的相对较慢的时间尺度.
- 该研究提供了使用先进的NMR技术了解膜蛋白的动态行为.
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