31P chemical shift anisotropy as an aid in determining nucleic acid structure in liquid crystals.
31P chemical shift anisotropy as an aid in determining nucleic acid structure in liquid crystals.
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31P 化学位移各向异性有助于确定液晶中的核酸结构。
DOI：
10.1021/ja015650x
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发表时间：
2001
影响因子：
15
通讯作者：
Bax,A
中科院分区：
文献类型：
--
作者：
Wu,Z;Tjandra,N;Bax,A
核酸中质子的低密度和远程NOE约束的缺乏使核磁共振结构测定成为一个众所周知的难题。1测量溶解在稀水液晶介质中的核酸的残余偶极偶联可以缓解这个问题，2-5但不能提供连接核苷酸的磷酸二酯键的直接信息。最近测量1H-31P偶极耦合的实验旨在解决这个问题，但由于相对较长的1H-31P距离和伴随的小偶极耦合，实验具有挑战性。6,7各向同性和排列样品之间的化学位移变化是由化学位移各向异性（CSA）引起的，也包含有价值的结构信息。8在这里，我们证明31P的大CSA可以有效地用于约束磷酸二酯基团相对于分子取向张量的取向，提高交叉验证判断的结构精度。
The low density of protons in nucleic acids and the paucity of long-range NOE restraints make NMR structure determination a notoriously difficult problem. 1 Measurement of residual dipolar couplings for nucleic acids dissolved in a dilute aqueous liquid crystalline medium can alleviate this problem, 2-5 but does not provide direct information on the phosphodiester linkages connecting the nucleotides. Recent experiments that measure 1H-31P dipolar couplings aim to address this problem, but are experimentally challenging because of the relatively long 1H-31P distances and concomitantly small dipolar couplings. 6, 7 Changes in chemical shift between isotropic and aligned samples are caused by chemical shift anisotropy (CSA) and also contain valuable structural information. 8 Here we demonstrate that the large CSA of 31P can be used effectively to constrain the orientation of the phosphodiester groups relative to the molecular alignment tensor, improving structural accuracy as judged by cross validation.