Comparison of magnetic properties of DNA-cetyltrimethyl ammonium complex with those of natural DNA
Comparison of magnetic properties of DNA-cetyltrimethyl ammonium complex with those of natural DNA
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DNA-十六烷基三甲基铵复合物与天然DNA磁性的比较
DOI：
10.1007/s11426-012-4507-z
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
J. Grote
中科院分区：
文献类型：
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作者：
Young‐Wan Kwon;Dong Hoon Choi;Jung;C. Lee;E. Koh;J. Grote
我们制备了DNA-十六烷基三甲基铵复合物，以及相同的复合物插入稳定的有机自由基，并研究了它们的磁性能，通过电子磁共振（EMR）光谱和超导量子干涉仪（SQUID）上测量的磁化强度。在有机溶剂中，DNA-季铵复合物（DNA−-Q+）的紫外-可见光谱和圆二色光谱清楚地表明，它保留了双螺旋B型构象。用长烷基季铵基团取代天然DNA中磷酸根的抗衡离子（Na+）后，双链DNA（dsDNA）的螺旋间距增大。用X射线衍射法测得DNA-十六烷基三甲基铵（CTMA）的螺旋间距为39.1 nm。通常，发现DNA-CTMA复合物固体的磁化强度显著低于天然DNA的磁化强度。此外，嵌入的复杂的稳定的有机自由基没有提高磁化，这再次是在天然DNA形成鲜明对比。固态配合物的EMR光谱行为也与天然DNA有很大的不同：天然DNA在低场区g值大于10的特有宽EMR信号在DNA-CTMA配合物中消失。
We prepared the DNA-cetyltrimethyl ammonium complex, as well as the same complex intercalated with stable organic free radicals, and studied their magnetic properties by electron magnetic resonance (EMR) spectroscopy and by measuring the magnetization on a superconducting quantum interference device (SQUID). The UV-vis and CD spectra of DNA-quaternary alkyl ammonium complex (DNA−-Q+) in organic solvent clearly demonstrated that it retained the double helical B-form conformation. The interhelical spacing of double strand DNA (dsDNA) increased when the counter ions (Na+) of phosphate groups of the natural DNA were replaced with the long alkyl quaternary ammonium groups. The inter-helical distance of DNA-cetyltrimethyl ammonium (CTMA) was 39.1 Å as confirmed by X-ray diffractometry. In general, the magnetization of the DNA-CTMA complex solid was found to be significantly lower than that of natural DNA. Moreover, intercalation of the complex with stable organic free radicals did not improve magnetization, which again was in marked contrast to natural DNA. EMR spectroscopic behavior of the complex in the solid state also was quite different from that of natural DNA: The unique broad EMR signal of natural DNA in the low field region withg-value greater than 10 disappeared in the DNA-CTMA complex.
DOI：
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发表时间：
1986
期刊：
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影响因子：
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作者：
T. Skotheim;R. Elsenbaumer;J. Reynolds
通讯作者：
T. Skotheim;R. Elsenbaumer;J. Reynolds