高盐度对水结构的影响
1European Molecular Biology Laboratory, Grenoble Outstation, BP 156, 38042 Grenoble Cedex, France.
Nature
|November 23, 1995
概括
水溶液中的离子破坏其结构,模仿高压. 这种与部分摩尔体积相关的离子特异效应影响蛋白质沉和盐分现象.
科学领域:
- 物理化学 物理化学
- 解决方案化学 解决方案化学
- 生物物理化学 生物物理化学
背景情况:
- 水的四面体结构对压力和温度都很敏感.
- 溶液中的离子可能会扰乱水的键网络.
- 了解离子-水相互作用对于各种化学和生物过程至关重要.
研究的目的:
- 为了比较施加压力的结构效应与水中的高盐度.
- 调查这些结构性扰动的离子特异性.
- 为了将离子诱导的结构变化与蛋白质化的有效性相关联.
主要方法:
- 采用中子衍射来探测不同条件下水的结构.
- 高度的盐和施加的压力系统地变化.
- 分析了与离子特性相关的结构变化.
主要成果:
- 离子诱导水中的结构变化相当于高压 (在几mol/L时超过1000 atm).
- 这种压力效应的大小是特定于离子物种的.
- 观察到诱导压力与离子在蛋白质化中的有效性之间存在相关性.
结论:
- 水结构的离子扰动类似于施加显著的水静压.
- 离子相对于水分子的部分摩尔体积解释了观察到的结构变化.
- 这项研究为了解蛋白质沉和溶液行为中的离子特异效应提供了分子基础.
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