...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Biomolecular Structure and Dynamics >Charges of phosphate groups. A role in stabilization of 2'-deoxyribonucleotides. A DFT investigation.
【24h】

Charges of phosphate groups. A role in stabilization of 2'-deoxyribonucleotides. A DFT investigation.

机译：磷酸基团的电荷。在稳定2'-脱氧核糖核苷酸中的作用。 DFT调查。

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

We have analyzed the relative stabilities and Gibbs tautomeric free energy for tautomeric transitions of neutral 2'-deoxyribonucleotides and its mono- and di-protonated forms. Geometry optimizations of these nucleic acid constituents have been performed at the DFT/B3LYP level using the standard 6-31G(d) basis set. The prediction of relative stabilities, Gibbs tautomeric free energy has been made at the B3LYP/6-311++G(d,p)//B3LYP/6-31G(d) level of theory. For each nucleoside four major conformers, i.e., north/anti, north/syn, south/anti, and south/syn have been taken into consideration. We have found the substantial effect of the uncompensated charge on the relative stability of 2'-deoxyribonucleotides. In particular, when the charge of 2'-deoxyribonucleotide anions is completely compensated by protons, the syn conformations have been found to be the global minima due to stabilization provided by intramolecular hydrogen bonds. However, the negative charge that appears due to the successive removal of the protons from the phosphate group destabilizes these syn conformations and stabilizes preferably the south/anti conformations (except of 2'-deoxyguanosine phosphate). Only 2'-deoxyribonucleotides, possessing south/anti and north/anti orientations, containing guanine and cytosine can contribute significantly to the rate of spontaneous point mutations due to the formation of biologically relevant amounts of 'rare' tautomers. However, we found strong influence of uncompensated negative charge for 2'-deoxyribonucleotides which possess syn conformations. Finally we have found that the proton transfer could result in the spontaneous change of 2'-deoxyribonucleotides conformations. We conclude that this phenomenon could be considered as a new way for the stabilization of 'rare' isomers for such DNA bases as cytosine and thymine.
机译：我们分析了中性2'-脱氧核糖核苷酸及其单质子化和双质子化形式的互变异构转变的相对稳定性和吉布斯互变异构自由能。这些核酸成分的几何优化已使用标准6-31G（d）基集在DFT / B3LYP水平进行。相对稳定性的吉布斯互变异构自由能的预测是在B3LYP / 6-311 ++ G（d，p）// B3LYP / 6-31G（d）的理论水平上进行的。对于每个核苷，已经考虑了四个主要构象体，即北/反，北/同，南/反和南/同。我们已经发现未补偿电荷对2'-脱氧核糖核苷酸的相对稳定性的实质影响。特别地，当2'-脱氧核糖核苷酸阴离子的电荷完全被质子补偿时，由于分子内氢键提供的稳定作用，发现顺式构象是全局最小值。然而，由于从磷酸基团中连续除去质子而出现的负电荷使这些顺式构象不稳定并且优选使南/反构象稳定（除了2'-脱氧鸟苷磷酸酯）。由于具有生物学相关量的“稀有”互变异构体，只有具有南/反和北/反方向，含有鸟嘌呤和胞嘧啶的2'-脱氧核糖核苷酸可以显着地促进自发点突变的速率。然而，我们发现未补偿的负电荷对具有顺式构象的2'-脱氧核糖核苷酸的强烈影响。最后，我们发现质子转移可能导致2'-脱氧核糖核苷酸构象的自发改变。我们得出结论，这种现象可以被视为稳定胞嘧啶和胸腺嘧啶等DNA碱基的“稀有”异构体的新方法。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号