DNA柔韧性的氢核磁共振研究。
1H nuclear magnetic resonance investigation of flexibility in DNA.
作者信息
Early T A, Kearns D R
出版信息
Proc Natl Acad Sci U S A. 1979 Sep;76(9):4165-9. doi: 10.1073/pnas.76.9.4165.
In this paper we report successful observations of proton NMR spectra of native double helical salmon sperm and calf thymus DNA of various lengths. Measurements of the linewidths arising from proton--proton dipolar interactions are used to obtain information about the dynamic behavior of DNA helices in solution. Depending upon which protons are used to monitor the local internal motions of the DNA, different results are obtained. The lowfield resonances from hydrogen-bonded imino protons in the base pairs indicate that the correlation time for reorientation of base pairs is less than 3 x 10(-7) sec, whereas correlation times for motion of neighboring sugar protons relative to the aromatic protons are less than 5 x 10(-8) sec for DNA that is over 200 base pairs long. These observations indicate that there is considerably more internal flexibility in the DNA molecues, especially in the backbone, than is indicated by classic hydrodynamic studies of DNA.
在本文中，我们报告了对不同长度的天然双螺旋鲑鱼精子和小牛胸腺DNA的质子核磁共振谱的成功观测。通过测量由质子 - 质子偶极相互作用产生的线宽，来获取有关DNA螺旋在溶液中动态行为的信息。根据用于监测DNA局部内部运动的质子不同，会得到不同的结果。碱基对中氢键合亚氨基质子的低场共振表明，碱基对重新取向的相关时间小于3×10⁻⁷秒，而对于长度超过200个碱基对的DNA，相邻糖质子相对于芳香族质子运动的相关时间小于5×10⁻⁸秒。这些观测结果表明，DNA分子，尤其是其主链，具有比经典DNA流体动力学研究所显示的更大的内部灵活性。
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