神奇的角度旋转NMR结构确定从伪接触转移的蛋白质
Jianping Li1, Kala Bharath Pilla, Qingfeng Li
1Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Centre for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences , Wuhan, 430071, PR China.
Journal of the American Chemical Society
|May 8, 2013
概括
这项研究引入了一种使用固态NMR和伪接触转移 (PCS) 来确定蛋白质结构的新方法,绕过了传统的距离限制. 这种方法可以对具有挑战性的生物宏分子进行高分辨率的结构确定.
科学领域:
- 生物物理学的生物物理.
- 结构生物学 结构生物学
- 核磁共振 (NMR) 光谱学 核磁共振 (NMR) 光谱学
背景情况:
- 固态NMR在难以结晶或太大而不能溶液NMR的生物宏分子的原子分辨率研究中至关重要.
- 传统的固态NMR结构确定在使用二极合光谱获得足够的远程距离限制方面面临挑战.
研究的目的:
- 开发一种用于固体阶段高分辨率蛋白质结构确定的新方法.
- 通过使用伪接触转移 (PCS) 和计算方法克服传统固态NMR的局限性.
主要方法:
- 通过向附着在蛋白质G的免疫球蛋白结合域 (GB1) 上的标签 (4-mercaptomethyl-dipicolinic acid) 合磁性金属离子来生成PCS (PCS).
- 将实验性PCS测量与罗塞塔计算相结合,得出远程结构约束.
- 采用多个偏磁离子和多个标签位置来增强固定装置的数量和覆盖范围.
主要成果:
- 成功地从实验PCS中提取了远程结构约束 (高达~20 Å),与X射线结构模型的逆向计算有很好的一致性.
- 证明了变化的磁性离子和标签地点显著增加了远程约束的数量和它们的空间覆盖.
- 通过使用固态NMR PCS限制和罗塞塔计算,生成了一个与其X射线结构相对的0.7 Å根平均平方偏差的蛋白质结构.
结论:
- 在固体阶段可以确定高分辨率的蛋白质结构,而无需传统的二极极-二极合束.
- PCS与计算方法相结合,为在固态NMR中获取远程结构信息提供了一个强大的工具.
- 这种方法为使用固态NMR的具有挑战性的生物宏分子的结构研究提供了一个有希望的替代方案.
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