(14) 用固态NMR光谱学研究的胺和二次结构的N四极合
Jun Fukazawa1, Shin-Ichi Kato, Takuo Ozaki
1Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
Journal of the American Chemical Society
|March 12, 2010
概括
这项研究表明,α螺旋体表现出更大的 (14) N 四极合,而不是中的β片. 这一发现有助于将二次结构与核四极相互作用相关联.
科学领域:
- 固态核磁共振 (NMR) 光谱学 固态核磁共振 (NMR) 光谱学
- 计算化学的计算化学
- 生物物理学的生物物理.
背景情况:
- 核四极合对核周围的局部电子环境敏感.
- 二次结构,如α螺旋和β片,施加不同的结构约束.
- 了解结构和光谱参数之间的关系对于分子表征至关重要.
研究的目的:
- 为了研究二次结构 (α-螺旋与β-片) 与 (14) N 四极合常数之间的相关性.
- 确定 (14) N 四极合是否可以作为聚酸中二次结构的可靠指标.
- 探索氨基酸成分对这种结构-光谱学关系的影响.
主要方法:
- 固态 (14) N NMR光谱法被用来测量 (14) N四极合.
- 在魔法角旋转下间接观察 (14) N 超音调共振.
- 在模型分子上进行了ab initio计算 (Gaussian03),以计算 (14) N四极合.
主要成果:
- 在alpha-helical和beta-sheet结构之间观察到 (14) N四极合的明显差异.
- 发现,α螺旋的四极合比β螺旋板的四极合总是大几百kHz.
- 这种差异独立于研究的特定氨基酸残留物 (Ala,Val,Leu).
结论:
- (14) N四极合是一种敏感的二次结构探测器.
- 与β-叶结构相比,α-螺旋结构具有显著更大的 (14) N四极合.
- 这种光谱参数可用于区分聚酸中的α-螺旋和β-片形状.
相关概念视频
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