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Determination of the Gas-phase Acidities of Oligopeptides
Published on: June 24, 2013
酸CH...O键的溶液和固态模型.
Paul W Baures1, Alicia M Beatty, Muthu Dhanasekaran
1Department of Chemistry, 111 Willard Hall, Kansas State University, Manhattan, Kansas 66506, USA. baures@signaturebio.com
Journal of the American Chemical Society
|September 19, 2002
概括
这项研究表明,CH...O相互作用与胺衍生物中的NH...O键同时发生,无论是在溶液中还是固态中. 这些发现为了解和蛋白质结构中类似相互作用提供了有价值的模型.
科学领域:
- 化学物理 化学物理
- 分子生物学分子生物学
- 晶体学 晶体学是指结晶学.
背景情况:
- 非共价相互作用,特别是键,对于分子结构和功能至关重要.
- 虽然CH...O相互作用比传统的N-H...O键较弱,但在稳定和蛋白质构造方面起着重要作用.
- 富玛胺衍生物作为研究这些相互作用的模型化合物.
研究的目的:
- 为了描述玛胺衍生物中CH...O相互作用的形成.
- 为了比较这些相互作用在溶液和固体状态.
- 建立胺衍生物作为和蛋白质结构中CH...O相互作用的模型.
主要方法:
- 使用1H核磁共振 (NMR) 谱法进行溶液分析.
- 使用X射线晶体学进行固态分析.
- 用甲酸-d (CDCl3) 中的化二甲基硫氧化物 (DMSO-d6) 进行了定位实验.
主要成果:
- 1H NMR光谱学揭示了CH组参与CH...O=S(CD3) 2键的下场化学转移,与NH...O=S(CD3) 2键的同时发生.
- 非参与的CH组在较高的DMSO-d6度下显示出最小的化学转移变化或上方转移.
- X射线晶体结构证实了CH...O=C键与分子间NH...O=C键的存在.
结论:
- 溶液NMR和固态晶体学都提供了证据,证明了胺衍生物中同时存在的CH...O和NH...O结.
- 在晶体结构中观察到的CH...O=C键类似于在蛋白质的反平行β-sheet结构中发现的.
- 富玛胺衍生物有效地模拟了与和蛋白质结构稳定性相关的CH...O相互作用.
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