蛋白质侧链动态和残余构造
Nikola Trbovic1, Jae-Hyun Cho, Robert Abel
1Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York 10032, USA.
Journal of the American Chemical Society
|December 25, 2008
概括
核磁共振 (NMR) 旋转放松探测局部蛋白质通过测量内部动力学. 这项研究验证了NMR的有效性.
科学领域:
- 生物物理学的生物物理.
- 结构生物学 结构生物学
- 计算生物学 计算生物学
背景情况:
- 蛋白质结构对于折叠和结合热力学至关重要.
- 核磁共振 (NMR) 旋转放松提供了一个独特的实验窗口,通过内部动力学了解局部蛋白质.
- 评估NMR自旋放松对度测量的准确性对于其在结构生物学中的应用至关重要.
研究的目的:
- 为了验证NMR自旋放松用于探测局部蛋白质构造的使用.
- 为了比较NMR衍生动力学的阿尔金因侧链与详细的分子动力学 (MD) 模拟.
- 为了研究氨酸侧链动态,盐桥稳定性和形态之间的关系.
主要方法:
- 在Escherichia coli核糖核酶H (RNase H) 中,对氨酸侧链N(epsilon) -H(epsilon) 键载体的图秒到纳秒动态进行了测量,使用NMR旋转放松.
- 用分子动力学 (MD) 模拟来提供对侧链形态动力学的机械洞察力.
- 对旋转机库的分析被用来调查侧链运动的可概括模式.
主要成果:
- 氨酸N(epsilon) 旋转放松测量与模拟的侧链形态关系良好.
- 核磁共振放松主要反映了瓜尼尼盐桥的持久性,表明保留了N{\displaystyle N} -H{\displaystyle H} 的键向量方向.
- 医学模拟显示,阿尔金因侧链的阿利法部分可以被破坏,而瓜尼尼组保持盐桥,掩盖NMR的灵活性.
结论:
- 核磁共振旋转放松是一种有效的方法来推断局部蛋白质构造,特别是在涉及盐桥的情况下.
- 侧链中的"动态脱"现象 (在氨酸,氨酸,谷氨酸,谷氨胺和甲氨酸中观察到) 可能是一个一般的生物物理策略.
- 动态解可以通过允许终端部分独立移动来最大限度地减少与蛋白质折叠和结合相关的性惩罚.
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