Ultrahigh Resolution Characterization of Domain Motions and Correlations by Multialignment and Multireference Residual Dipolar Coupling NMR
Ultrahigh Resolution Characterization of Domain Motions and Correlations by Multialignment and Multireference Residual Dipolar Coupling NMR
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DOI：
10.1021/jp806188j
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发表时间：
2008-12-25
影响因子：
3.3
通讯作者：
Al-Hashimi, Hashini M.
中科院分区：
文献类型：
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作者：
Fisher, Charles K.;Zhang, Qi;Al-Hashimi, Hashini M.
核磁共振（NMR）残余偶极耦合（rdc）为生物分子复杂运动的空间表征提供了独特的机会，时间尺度灵敏度可达毫秒。在五种线性独立的对准条件下测量的rdc，可以通过实验确定多达五个运动平均的Wigner旋转元素< D-0k(2)(alpha beta)>，并应用于定义轴对称键向量的运动。在这里，我们展示了多达25个运动平均的Wigner旋转元素，< D-mk(2)(alpha beta gamma)>，可以从多取向rdc实验中确定，并用于表征手性域的刚体运动。25 < D-mk(2)(alpha beta gamma)>元素形成一个基集，允许人们测量相对于锚定在第二域上的参考帧的各向同性分布的域的运动（反之亦然），从而扩展了运动可以表征的3D空间分辨率。25 < D-mk(2)(α - β - γ)>元素也可以用来拟合由Lip到8个等或6个不等填充态组成的系综。对于两个以上的域，更改控制对齐的域的标识允许访问有关域波动的相关性质的新信息。实例仿真验证了理论推导，并说明了使用多对准和多参考rdc表征刚体域运动的高空间分辨率。我们的结果进一步激发了实验方法的发展，用于调制对准和锚定特定目标域。
Nuclear magnetic resonance (NMR) residual dipolar couplings (RDCs) provide it unique opportunity for spatially characterizing complex motions in biomolecules with time scale sensitivity extending up to milliseconds. Up to five motionally averaged Wigner rotation elements, < D-0k(2)(alpha beta)>, can be determined experimentally using RDCs measured in five linearly independent alignment conditions and applied to define motions of axially symmetric bond vectors. Here, we show that up to 25 motionally averaged Wigner rotation elements, < D-mk(2)(alpha beta gamma)>, can be determined experimentally from multialignment RDCs and used to characterize rigid-body motions of chiral domains. The 25 < D-mk(2)(alpha beta gamma)> elements form a basis set that allows one to measure motions of a domain relative to an isotropic distribution of reference frames anchored on a second domain (and vice versa), thus expanding the 3D spatial resolution with which motions can be characterized. The 25 < D-mk(2)(alpha beta gamma)> elements can also be used to fit an ensemble consisting of Lip to eight equally or six unequally populated states. For more than two domains, changing the identity of the domain governing alignment allows access to new information regarding the correlated nature of the domain fluctuations. Example simulations are provided that validate the theoretical derivation and illustrate the high spatial resolution with which rigid-body domain motions can be characterized using multialignment and multireference RDCs. Our results further motivate the development of experimental approaches for both modulating alignment and anchoring it oil specifically targeted domains.