特定于残留物的振动回声产生了跨膜螺旋体二元体的3D结构
Amanda Remorino1, Ivan V Korendovych, Yibing Wu
1Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323, USA.
Science (New York, N.Y.)
|June 4, 2011
概括
二维振动回声光谱学确定了一个复杂的跨膜蛋白质二度体的结构. 这种方法精确地绘制了蛋白质在膜环境中的螺旋结构和动态.
科学领域:
- 生物物理学的生物物理.
- 结构生物学 结构生物学
- 频谱学是一种光谱学.
背景情况:
- 二维 (2D) 振动回声光谱是一种强大的结构确定技术.
- 之前的应用集中在较小的类系统上.
- 集成蛋白α ((IIb) β ((3) 是一种生物学上至关重要的跨膜蛋白,参与细胞粘附.
研究的目的:
- 为了将二维振动回声光谱扩展到复杂的生物系统:整合素α链的同位体跨膜二元体α{\displaystyle \alpha }{\displaystyle \alpha }{\displaystyle \alpha }{\displaystyle \alpha }{\displaystyle \alpha }{\displaystyle \alpha }{\displaystyle \alpha }{\displaystyle \alpha }{\displaystyle \alpha }{\displaystyle \alpha }{\displaystyle \alpha }}{\displaystyle \alpha }{\displaystyle \alpha }{\displaystyle \alpha }{\displaystyle \alpha }}
- 为了确定这个跨膜二次体的三级结构和动态.
- 研究重同位素在结构分析中的作用.
主要方法:
- 制备30个残留的跨膜二元链的微粒悬浮物.
- 在特定的骨干位置 (第10至20位) 加入重同位素 ((13) C=(18) O).
- 2D振动回声谱的应用,以分析振动合和频率相关性.
主要成果:
- 确定了超膜二元体的优化结构,揭示了平行右手螺旋二元体.
- 确定了由Glycine残留物在位置12,15和16形成的三级接触点.
- 量化螺旋交叉角度 (-58° ± 9°) 和螺旋间距离 (7.7 ± 0.5 Å).
- 建立了动态模型,并指出没有与标记残留物相关的移动水.
- 在螺旋之间定量确定的振动激发移位.
结论:
- 2D振动回声谱对于复杂的跨膜蛋白质二次体的结构和动态分析是有效的.
- 确定的结构提供了关于整合素α(IIb) β(3) 功能的见解.
- 这项研究证明了特定于地点的同位素标签对于先进的结构研究的有用性.
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