蛋白质的表面介电常数及其温度依赖于远程化学转移效应
Liaoyuan An1, Yefei Wang, Ning Zhang
1Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences , Qingdao, 266101, China.
Journal of the American Chemical Society
|September 6, 2014
概括
这项研究引入了一种新的NMR协议,用于测量蛋白质中的电场变化. 该方法准确量化化学转移扰动 (CSP),并揭示温度依赖的介电性质.
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:
- 蛋白质突变可以改变电场,影响分子相互作用.
- 远程测量这些微妙的电场变化是具有挑战性的.
- 核磁共振 (NMR) 是研究蛋白质结构和动态的强大工具.
研究的目的:
- 开发和验证核磁共振 (NMR) 协议,以准确测量远程化学转移扰动 (CSP).
- 调查突变引起的电场变化与CSP之间的关系.
- 为了确定蛋白质的表面介电常数 (εa) 和其温度依赖.
主要方法:
- 使用了一种新型的NMR协议来测量GB3蛋白突变体 (K19A和K19E) 中的 (1) H (N) CSP.
- 应用了白金汉方程来将CSP与电场变化相匹配.
- 在明确溶剂中进行分子动力学模拟.
主要成果:
- 由突变引起的电场变化引起的微小,远程CSP的精确测量得到了实现.
- 对于蛋白质GB3.3,在298K时确定了8.6 ± 0.8的表面介电常数 (εa).
- CSP和衍生的eA值显示出强烈的温度依赖性,eA从7.3在278K上升到10.5在313K.
- 分子动力学模拟突出了溶剂水对eA的显著贡献.
结论:
- 开发的NMR协议可以精确量化蛋白质内部的电场干扰.
- 这项研究提供了对蛋白质的介电性质和温度的影响的见解.
- 溶剂水在所观察到的蛋白质介电行为中起着至关重要的作用.
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