五基GGAGG具有PII形状的五基
Liang Ding1, Kang Chen, Paul A Santini
1Department of Chemistry, New York University, 100 Washington Square East, New York, NY 10003, USA.
Journal of the American Chemical Society
|July 3, 2003
概括
未折叠的蛋白质可能会采用PII结构的显著群体,延伸的左手螺旋. 这项研究使用模型来显示氨酸残留有利于PII构造,影响未折叠的蛋白质.
科学领域:
- 蛋白质的结构和动态.
- 生物物理化学 生物物理化学
- 合规性分析是指对合规性的分析.
背景情况:
- 蛋白质结构主要研究其原生折叠状态.
- 展开的蛋白质的结构,通常被称为"随机线圈",不太了解.
- 新出现的证据表明,未折叠的蛋白质可能会采用普遍的PII螺旋结构.
研究的目的:
- 通过模型系统研究未折叠蛋白质的结构偏好.
- 为了分析PII结构的采用,在一个最小的中通过氨酸残留物.
- 探索温度对未折叠状态中的蛋白质二次结构的影响.
主要方法:
- 合成的AcGGXGGNH2,与X作为阿拉宁.
- 核磁共振 (NMR) 光谱法用于确定二面角 (Phi和Psi).
- 循环二元化 (CD) 光谱用于二次结构分析.
- 温度依赖的研究观察形状变化.
主要成果:
- 核磁共振数据证实,氨酸的Phi和Psi角 (-73°,125°) 位于Ramachandran图的PII区域内.
- 磁盘光谱检测显示了一种特有的PII光谱,在190nm时具有强烈的负吸收.
- 温度依赖的实验表明,在高温下,β链结构向β链结构转移.
结论:
- 模型AcGGAGGNH2采用稳定的PII形状,支持其在未折叠蛋白中的流行.
- 氨酸残留物,代表了的骨干,对展开的多的结构有显著的贡献.
- 这些发现为蛋白质展开和构造性障碍的结构基础提供了关键的见解.
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