相关实验视频
Updated: Jul 6, 2026

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Determination of the Gas-phase Acidities of Oligopeptides
Published on: June 24, 2013
在未溶化酸中直接探测zwitterion形成
Rodolphe Antoine1, Michel Broyer, Philippe Dugourd
1Laboratoire de Spectrométrie Ionique et Moléculaire, UMR No. 5579, CNRS et Université Lyon 1, 43 bd du 11 novembre 1918, 69622 Villeurbanne Cedex, France.
Journal of the American Chemical Society
|September 17, 2004
概括
基于氨酸的的电感受性揭示了它们的电荷分布. 测量结果与正规形式一致,这表明zwitterions由于分子内约束而在热方面不利.
科学领域:
- 物理化学 物理化学
- 计算化学计算化学
- 生物物理学的生物物理.
背景情况:
- 了解的结构和电荷分布对于分子的识别和功能至关重要.
- 区分zwitterionic和canonical形式的酸盐对于预测它们的行为至关重要.
- 电敏性为分子电荷分布提供了洞察力.
研究的目的:
- 用分子束电偏移来确定小,未溶解的氨基基的电敏感性.
- 研究这些的电荷分布和结构偏好 (zwitterionic与canonical形式).
- 将实验测量与计算模拟进行比较.
主要方法:
- 对WAn (n=1-5) 进行了分子束电偏移测量.
- 基于模拟炼的计算方法被用来计算电感应度.
- 进行了符合性分析,以确定最低能量和最低自由能量结构.
主要成果:
- 对WAn的电感受度与无法形成zwiwterion的封闭的电感受度相似.
- 对zwitterionic形式的计算敏感性明显高于正规形式.
- 实验数据与规范形式的计算敏感性强烈一致.
- 对于较大的,模拟显示了类似发针的最低潜在能量结构,并在室温下扩展了最低自由能量结构.
- 发现zwitterionic形式由于分子内相互作用而在热方面不利.
结论:
- 在实验条件下,对于小,未溶解的氨基基在实验条件下,佳能形式是最受欢迎的.
- 由于热处罚,这些酸中zwiwterion的形成受到不利影响.
- 分子束电偏移是一种有价值的技术,用于探测结构和电荷状态.
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