Calculation of the HOMO localization of Tetrahymena and Oxytricha telomeric quadruplex DNA.
Calculation of the HOMO localization of Tetrahymena and Oxytricha telomeric quadruplex DNA.
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四膜虫和尖毛虫端粒四链体 DNA 的 HOMO 定位的计算。
DOI：
10.1016/j.bmcl.2015.05.050
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Miyazawa H.
中科院分区：
文献类型：
--
作者：
Morikawa M.;Kino K.;Oyoshi T.;Suzuki M.;Kobayashi T.;Miyazawa H.
一些富含鸟嘌呤的序列存在于许多重要区域，如端粒，并且这些序列可以形成四链体DNA结构。在四膜虫和尖毛虫的端粒四链体DNA d（TGGGGT）4中，3′-鸟嘌呤主要被氧化;在人的端粒四链体DNA d（TAGGGT）4 T中，5′-鸟嘌呤主要被氧化。我们推测d（TGGGGT）4和d（TAGGGT）4 T之间的位点反应性差异是由HOMO的定位引起的。结果表明，d（TGGGGT）4+ 3 K+和d（TAGGGT）4 T +2K+的HOMO主要位于5′-鸟嘌呤上，且由于5′-帽阳离子的加入，HOMO从5′-鸟嘌呤转移到3′-鸟嘌呤上.此外，我们确定了阳离子的影响，并证明了本地化的HOMO在G-四重平面位于紧邻的阳离子是不利的。计算的d（TGGGGT）4+4K+和d（TAGGGT）4 T +2K+的HOMO局域化与实验结果相吻合，表明d（TGGGGT）4在溶液中含有一个5′-封端阳离子.
Several guanine-rich sequences exist in many important regions, such as telomeres, and these sequences can form quadruplex DNA structures. It was previously reported that 3′-guanines are mainly oxidized in the Tetrahymena and Oxytricha telomeric quadruplex DNA, d(TGGGGT)4, and 5′-guanines are mainly oxidized in the human telomeric quadruplex DNA, d(TAGGGT)4T. We speculated that the differences in site reactivity between d(TGGGGT)4and d(TAGGGT)4T are induced by the localization of the HOMO. The HOMOs of the possible quadruplex structures were thus determined and the results showed that the HOMOs of d(TGGGGT)4+3K+and d(TAGGGT)4T +2K+localized at the 5′-guanine, and that the HOMO shifted from the 5′-guanine to the 3′-guanine by the addition of a 5′-capping cation. Furthermore, we determined the influence of the cation and demonstrated that localization of the HOMO at the G-quartet plane located immediately adjacent to the cation is disfavored. The calculated HOMO localization of d(TGGGGT)4+4K+and d(TAGGGT)4T +2K+matched the experimental results and suggest that d(TGGGGT)4contains a 5′-capping cation in solution.