Rotational diffusion tensor of nucleic acids from 13C NMR relaxation
Rotational diffusion tensor of nucleic acids from 13C NMR relaxation
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DOI：
10.1023/a:1024931619957
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发表时间：
2003-10-01
影响因子：
2.7
通讯作者：
Bax, A
中科院分区：
文献类型：
--
作者：
Boisbouvier, J;Wu, ZR;Bax, A
通过C-13均匀富集样品中C-1′、C-3′和C-4′碳的R-1和R-1测量，得到了DNA十二聚体d(CGCGAATTCGCG)(2)的旋转扩散特性。相对于DNA轴的C-H键矢量方向的狭窄范围使分析对小的结构偏差特别敏感。因此，R-1rho/R-1比值被发现与这种十二聚体的晶体结构不太吻合，但与最近在液晶介质中测定的溶液核磁共振结构吻合得很好，尽管整体结构非常相似。对于轴对称旋转扩散模型，R-1rho/R-1比值与溶液结构的拟合是最佳的，扩散各向异性（d -平行/ d -垂直）为2.1+/-0.4，总体旋转相关时间（2D（平行）+ 4D（垂直））（-1）在D2O中35°c时为3.35 ns，与流体动力学模型的值非常吻合。
Rotational diffusion properties have been derived for the DNA dodecamer d(CGCGAATTCGCG)(2) from C-13 R-1rho and R-1 measurements on the C-1', C-3', and C-4' carbons in samples uniformly enriched in C-13. The narrow range of C-H bond vector orientations relative to the DNA axis make the analysis particularly sensitive to small structural deviations. As a result, the R-1rho/R-1 ratios are found to fit poorly to the crystal structures of this dodecamer, but well to a recent solution NMR structure, determined in liquid crystalline media, even though globally the structures are quite similar. A fit of the R-1rho/R-1 ratios to the solution structure is optimal for an axially symmetric rotational diffusion model, with a diffusion anisotropy, D-parallel to/D-perpendicular to, of 2.1+/-0.4, and an overall rotational correlation time, (2D(parallel to) + 4D(perpendicular to))(-1), of 3.35 ns at 35degreesC in D2O, in excellent agreement with values obtained from hydrodynamic modeling.