胺-胺和胺-水键:对蛋白质折叠和稳定性的影响
Eric S Eberhardt1, Ronald T Raines
1Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706.
Journal of the American Chemical Society
|May 10, 2011
概括
二次胺是比水或胺更弱的键捐赠者,影响蛋白质折叠模型. 这表明侧链-主链键可能比主链-主链键更能稳定蛋白质.
科学领域:
- 生物化学 生物化学
- 化学物理 化学物理
- 分子生物学分子生物学
背景情况:
- 氨基胺-氨基胺键在蛋白质折叠和稳定性中起着至关重要的作用.
- 了解不同胺环境的结能力是阐明蛋白质结构形成的关键.
- 之前的模型表明,在蛋白质二次结构形成中,疏水性崩后的合作过程.
研究的目的:
- 为了比较二次胺基的键捐赠能力与形式胺基和水.
- 为了研究胺溶剂对烯酸键的 cis-trans 异构化速率的影响.
- 分析溶剂对含有素的胺I振动模式的影响.
主要方法:
- 使用逆转移 (13)C核磁共振 (NMR) 谱学.
- 使用红外 (IR) 光谱仪进行振动模式分析.
- 研究的模型:Ac-Gly-[β,δ-(13) C]Pro-OMe和[(13) C=O]Ac-Pro-OMe. 这两种类型的都被研究了.
主要成果:
- 二次胺与胺和水相比,其键捐赠能力明显较弱.
- 基键的 cis-trans 异体化速率被不同胺溶剂和水所改变.
- 林键的胺I振动模式显示了溶剂依赖的变化.
结论:
- 这些发现支持蛋白质折叠模型,其中二次结构形成是合作的,并遵循疏水性崩.
- 涉及阿斯巴拉金或谷氨胺侧链的主链键可能比主链-主链相互作用提供更大的蛋白质稳定性.
- 相对的键强度影响了和蛋白质结构的动态和稳定性.
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