在溶液中的分子间自由能量的局部测量
Ching-Ling Teng1, Silvia Martini, Robert G Bryant
1Chemistry Department and Biophysics Program, University of Virginia, Charlottesville, Virginia 22904, USA.
Journal of the American Chemical Society
|November 19, 2004
概括
自由扩散的氧气揭示了与氨基酸和溶液中的葡萄糖的弱疏水性关联. 这项研究使用质子自旋格子放松测量量量这些相互作用的能量效益.
科学领域:
- 生物物理化学 生物物理化学
- 解决方案化学 解决方案化学
- 分子相互作用 分子相互作用
背景情况:
- 质子自旋网放松对分子运动和局部环境敏感.
- 氧气的磁性特性可用于探测溶液中的分子相互作用.
- 了解溶解物-溶剂相互作用在各种化学和生物系统中至关重要.
研究的目的:
- 测量氨基酸和葡萄糖周围的局部氧气度.
- 研究氧气与不同分子位点的关联的能量基础.
- 探索溶剂成分对这些相互作用的影响.
主要方法:
- 在水溶剂和混合溶剂中测量质子自旋晶格放松率.
- 分析对放松的偏磁性贡献,以确定局部氧气度.
- 与无力扩散模型进行比较,以计算协会的自由能量.
主要成果:
- 观察到氧与水中的氨基酸质子相关的负自由能差异 (-800到-2000 J/mol),表明弱的疏水相互作用.
- 葡萄糖中的CH质子位置显示负的自由能量,取决于溶剂.
- 葡萄糖中的基位表现出正的自由能量差异,这表明溶剂的键.
结论:
- 自由扩散的氧气可以探测溶液和辅溶剂之间的弱疏水性联系.
- 氧结合的能量优势在不同溶解物质质子位点上有所不同.
- 溶剂效应和键显著影响氧溶液相互作用.
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