特定离子调节液化水在脂质膜表面的扩散动态
Jinsuk Song1, John Franck, Philip Pincus
1Department of Chemistry and Biochemistry and ‡Materials and Physics Department, University of California, Santa Barbara , Santa Barbara, California 93106, United States.
Journal of the American Chemical Society
|January 25, 2014
概括
特定的离子会影响脂质囊泡附近的水扩散,霍夫迈斯特离子会改变水的结合强度. 这项研究揭示了离子如何影响表面水的动态和结合.
科学领域:
- 物理化学 物理化学
- 生物物理学的生物物理.
- 表面科学是一门学科.
背景情况:
- 了解界面上的水动态对于生物和化学过程至关重要.
- 脂质囊泡是细胞膜的常见模型系统.
- 霍夫迈斯特系列描述了离子对蛋白质溶解度和其他现象的特异性影响.
研究的目的:
- 为了研究特定离子对水的翻译扩散在性脂质囊泡表面附近的作用.
- 量化水友界面上的水扩散的延迟.
- 为了确定离子诱导的水扩散变化是否与霍夫迈斯特系列相关.
主要方法:
- 使用Overhauser动态核极化 (ODNP) 来测量局部水的扩散.
- ODNP利用气囊表面上的电子自旋探针,探测~10 Å内的水动力学.
- 高频 (10 GHz) 核磁共振放松计能够测量皮秒到亚纳秒的水动力学.
主要成果:
- 在水友性囊泡表面的~10 Å内,水的扩散速度大约是散装水的5倍.
- 特定离子的存在调节了这种地表水扩散延迟.
- 离子对水扩散的影响的顺序遵循霍夫迈斯特系列.
结论:
- 霍夫迈斯特离子直接调节水在水友表面的扩散性.
- 这种调制意味着对表面水化水的键网络强度产生直接影响.
- 虽然精确的分子机制需要进一步研究,但对表面水动态的离子特异效应已经过实验证实.
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