噬菌体M13和烟草花叶病毒的二维交换31P核磁共振光谱学
2D exchange 31P NMR spectroscopy of bacteriophage M13 and tobacco mosaic virus.
作者信息
Magusin P C, Hemminga M A
机构信息
Department of Molecular Physics, Wageningen Agricultural University, The Netherlands.
出版信息
Biophys J. 1995 Mar;68(3):1128-36. doi: 10.1016/S0006-3495(95)80287-0.
Two-dimensional (2D) exchange 31P nuclear magnetic resonance spectroscopy is used to study the slow overall motion of the rod-shaped viruses M13 and tobacco mosaic virus in concentrated gels. Even for short mixing times, observed diagonal spectra differ remarkably from projection spectra and one-dimensional spectra. Our model readily explains this to be a consequence of the T2e anisotropy caused by slow overall rotation of the viruses about their length axis. 2D exchange spectra recorded for 30% (w/w) tobacco mosaic virus with mixing times < 1 s do not show any off-diagonal broadening, indicating that its overall motion occurs in the sub-Hz frequency range. In contrast, the exchange spectra obtained for 30% M13 show significant off-diagonal intensity for mixing times of 0.01 s and higher. A log-gaussian distribution around 25 Hz of overall diffusion coefficients mainly spread between 1 and 10(3) Hz faithfully reproduces the 2D exchange spectra of 30% M13 recorded at various mixing times in a consistent way. A small but notable change in diagonal spectra at increasing mixing time is not well accounted for by our model and is probably caused by 31P spin diffusion.
二维（2D）交换31P核磁共振光谱法用于研究杆状病毒M13和烟草花叶病毒在浓缩凝胶中的整体缓慢运动。即使混合时间很短，观察到的对角光谱与投影光谱和一维光谱也有显著差异。我们的模型很容易解释这是病毒围绕其长度轴的整体缓慢旋转引起的T2e各向异性的结果。对于30%（w/w）烟草花叶病毒，在混合时间<1 s时记录的二维交换光谱没有显示出任何非对角展宽，这表明其整体运动发生在亚赫兹频率范围内。相比之下，对于30% M13获得的交换光谱在混合时间为0.01 s及更长时显示出显著的非对角强度。整体扩散系数主要分布在1至10³ Hz之间，围绕25 Hz的对数高斯分布以一致的方式忠实地再现了在不同混合时间记录的30% M13的二维交换光谱。随着混合时间增加，对角光谱有一个小但显著的变化，我们的模型对此解释得并不充分，这可能是由31P自旋扩散引起的。
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