一个环和一个质子胺之间的简单的阴离子-皮相互作用稳定了水中的α螺旋
Lun K Tsou1, Chad D Tatko, Marcey L Waters
1Department of Chemistry, Venable and Kenan Laboratories, CB 3290, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
Journal of the American Chemical Society
|December 12, 2002
概括
阴离子-pi 相互作用,如氨酸...甲基氨酸,可以稳定蛋白质结构. 这项研究量化了它们的稳定性,揭示了影响蛋白质稳定性的微妙因素.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 计算化学的计算化学
背景情况:
- 建议-π相互作用以稳定蛋白质结构,特别是在暴露于溶剂的表面.
- 简单的-π相互作用对蛋白质稳定性的精确贡献需要进一步研究.
研究的目的:
- 量化氨酸与各种氨基酸 (lysine, ornithine, diaminobutanoic acid) 之间在α-helix中发生的阴离子-pi相互作用的稳定作用.
- 为了比较这些相互作用的强度与已知的稳定力,如盐桥和其他阴离子-皮相互作用.
主要方法:
- 在阿尔法螺旋模型中对阴离子-π相互作用进行计算研究.
- 对与lysine,ornithine和diaminobutanoic acid相互作用的 fenylalanine 的能量计算.
主要成果:
- 氨酸...氨酸的相互作用显著稳定了α-螺旋体的 -0.4 kcal/mol.
- 这种稳定能量可与α螺旋体中的盐桥相提并论.
- 观察到的相互作用强度不同于基于阴离子类型 (氨与瓜尼迪尼) 的预测.
结论:
- 即使是简单的阴离子-pi相互作用,如氨酸,也可以为蛋白质结构提供相当大的稳定性.
- 微妙的因素,不仅仅是相互作用组的基本性质,显著影响蛋白质中的阴离子-皮相互作用能量.
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