Direct measurement of distances and angles in biomolecules by NMR in a dilute liquid crystalline medium
Direct measurement of distances and angles in biomolecules by NMR in a dilute liquid crystalline medium
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DOI：
10.1126/science.278.5340.1111
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发表时间：
1997-11-07
期刊：
影响因子：
56.9
通讯作者：
Bax, A
中科院分区：
文献类型：
--
作者：
Tjandra, N;Bax, A
在各向同性溶液中，由于旋转扩散，核间偶极耦合平均为零。通过将大分子溶解在含有宽间隔的磁取向颗粒的稀水性双折射液晶介质中，可以产生与磁场的可调程度的溶质对准，同时保持规则各向同性核磁共振（NMR）谱的高分辨率和灵敏度。在这种定向的大分子中，H-1-H-1、H-1-C-13、H-1-N-15和C-13-C-13对之间的偶极偶联不再平均为零，并且容易测量。从人泛素偶极偶联得到的距离和角度与其晶体结构非常一致。该方法有望提高NMR测定结构的准确性，并扩展尺寸限制。
In isotropic solution, internuclear dipolar couplings average to zero as a result of rotational diffusion. By dissolving macromolecules in a dilute aqueous nematic discotic liquid-crystalline medium containing widely spaced magnetically oriented particles, a tunable degree of solute alignment with the magnetic field can be created while retaining the high resolution and sensitivity of the regular isotropic nuclear magnetic resonance (NMR) spectrum. Dipolar couplings between H-1-H-1, H-1-C-13, H-1-N-15, and C-13-C-13 pairs in such an oriented macromolecule no longer average to zero, and are readily measured. Distances and angles derived from dipolar couplings in human ubiquitin are in excellent agreement with its crystal structure. The approach promises to improve the accuracy of structures determined by NMR, and extend the size limit.