力驱动一个附着的水分子从C端到N端在质子化proline上
James S Prell1, Thiago C Correra, Terrence M Chang
1Department of Chemistry, University of California, Berkeley, California 94720-1460, USA.
Journal of the American Chemical Society
|October 5, 2010
概括
随着温度的增加,质子化的化转移从碳酸到N端. 这种温度依赖的质子化素的结合偏好是由不同的体和体因素驱动的.
科学领域:
- 化学物理 化学物理
- 频谱学是一种光谱学.
- 氨基酸化学 氨基酸化学
背景情况:
- 质子化氨基酸表现出复杂的水化结构.
- 了解特定地点的水相互作用对于生物分子溶解研究至关重要.
研究的目的:
- 为了研究质子的温度依赖的水位偏好.
- 阐明水与质子烯结合背后的热力学驱动力.
主要方法:
- 红外光解离 (IRPD) 光谱法用于探测水化结构.
- 作为温度的函数,对水化异构体进行了动态分析.
- 范特霍夫图表是从动力学数据生成的,以确定热力学参数.
主要成果:
- 单一水合,质子化烯在低温下显示对碳酸位点的偏好.
- 在更高的温度下,水优先与质子化N端结合.
- C终端的结合在度上受益 (4.26.4 kJ/mol),而N终端的结合在度上受益 (3143 J/mol K)).
结论:
- 质子的水位对温度敏感,从C端切换到N端.
- 和的差异决定了观察到的取决于温度的水合偏好.
- 对水分子旋转的计算障碍表明在C端有一个更高的障碍,影响结合.
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