紫外线拉曼 (UV Raman) 证明,α-螺旋型聚氨酸可以融化为聚氨酸II形状
Sanford A Asher1, Alexander V Mikhonin, Sergei Bykov
1Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA. asher@pitt.edu
Journal of the American Chemical Society
|July 9, 2004
概括
溶液中的采用主导的聚二烯 (PPII) 构造,而不是无序的状态. 紫外线拉曼光谱提供了一种分析结构和Ramachandran Psi-angle分布的新方法.
科学领域:
- 生物物理学的生物物理.
- 频谱学是一种光谱学.
- 结构生物学 结构生物学
背景情况:
- 核磁共振 (NMR) 研究表明,XAO在水溶液中采用聚二烯II (PPII) 构型.
- 像ala(5) 这样的小和一个更大的富含氨酸的 (AP) 与XAO.共享类似的光谱特征.
研究的目的:
- 使用紫外线拉曼光谱学研究溶液中的的二次结构.
- 开发和应用一种新的方法来估计Ramachandran Psi-angle分布从胺III频段的频率.
- 为了比较各种和蛋白质的Psi角分布.
主要方法:
- 采用204nm紫外线拉曼光谱来分析形状.
- 开发了一种新的方法来将胺III频段频率与Ramachandran Psi-angle相关联.
- 估计了XAO,ala(5),AP的非alpha螺旋状态,酸变质的阿波米球蛋白和蛋白质中的键的psi角分布.
主要成果:
- XAO,ala(5) 和AP的紫外线拉曼光谱几乎相同,这表明非alpha-helical状态的PPII构造占主导地位.
- AP从一个α-螺旋状态过渡到一个PPII形状.
- 没有观察到中间无序形状的证据.
- 开发的方法成功估计了各种和蛋白质样本的Psi-角分布.
结论:
- 这些的非α螺旋形状主要是PPII.
- 紫外线拉曼光谱是和蛋白质结构分析的宝贵工具.
- 这种新方法提供了对Ramachandran Psi-angle分布在各种结构上下文中的见解.
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