未溶解的水化过程中的初步步骤:在以氨酸为基础的螺旋和球体上吸附水分子
Motoya Kohtani1, Martin F Jarrold
1Contribution from the Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA.
Journal of the American Chemical Society
|September 13, 2002
概括
与螺旋结构相比,当具有球状形状时,可以更容易地与水结合. 强大的水结合取决于形成键,电荷屏蔽影响相互作用强度.
科学领域:
- 化学物理 化学物理
- 生物物理化学 生物物理化学
- 计算化学计算化学
背景情况:
- 了解-水相互作用对于各种化学和生物过程至关重要.
- 结构,电荷和成分对水吸附的影响仍然是活跃的研究领域.
研究的目的:
- 量化第一个水分子对未溶解的氨酸基的吸附.
- 调查形状,电荷和组成对水结合亲和力的影响.
- 为了将水吸附的热力学参数 (和) 相对应.
主要方法:
- 对水吸附的平衡常数的实验测量.
- 确定吸附过程中的 (ΔH°) 和 (ΔS°) 的变化.
- 使用分子动力学模拟进行验证.
主要成果:
- 球状比螺旋的吸附水是显著更有利的球状.
- 一些单充电的螺旋,即使在-50°C,也没有水吸附.
- 强大的水结合与形成键网络的能力有关.
- 电荷屏蔽严重影响充电点的水吸附.
- 由于电荷移位,质子化含有伊斯蒂丁的蛋白比质子化含有素的蛋白更强烈地与水结合.
结论:
- 体构成和电荷可访问性是水吸附的关键决定因素.
- 形成一个强大的键网络对于强大的水结合至关重要.
- 水吸附的热力学参数 (ΔH°和ΔS°) 是相互连接的.
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