阴离子-π 相互作用和Na(+) /氨酸复合物的气相热化学
1Chemistry Department, Case Western Reserve University, Cleveland, OH 44106, USA.
Journal of the American Chemical Society
|August 23, 2001
概括
与氨酸结合的离子对生物相互作用至关重要. 这项研究证实了氨相互作用在氨相互作用中的重要作用.
科学领域:
- 生物物理化学 生物物理化学
- 计算化学计算化学
- 生物化学 生物化学
背景情况:
- 在生物系统中,-相互作用至关重要.
- 以前的研究质疑了氨酸的环对离子结合的贡献.
- 了解这些相互作用是解读生物分子中金属离子结合的关键.
研究的目的:
- 重新检查与氨酸 (Phe) 和氨酸 (Ala) 结合的离子的热化学反应.
- 量化-π相互作用在Phe-Na(+) 复合体形成中的贡献.
- 验证研究这些相互作用的计算方法.
主要方法:
- 使用里叶变换离子循环子共振 (FT-ICR) 质谱测量交换平衡的测量.
- 使用皮里丁作为参考配体进行热化学分析.
- 量子化学计算 (密度函数和哈特里-福克/MP2方法).
主要成果:
- 与Ala相比,对Phe观察到7 +/- 2 kcal mol ((-1) 的度增加,证实了增强的结合.
- 确定了绝对Na(+) 结合度:Ala的38 +/- 2 kcalmol(-1) 和Phe的45 +/- 2 kcalmol(-1) 的绝对度.
- 计算方法支持实验发现,并揭示了Phe的新低能度结构.
结论:
- 阴离子-pi 相互作用显著增强了离子与氨酸的结合.
- 这项研究提供了对Na(+) 与氨基酸结合的准确热化学数据.
- 计算和实验方法成功地结合在一起,以阐明这些分子相互作用.
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