...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Proceedings of the National Academy of Sciences of the United States of America >(G-H)(center dot)-C and G-(C-H)(center dot) radicals derived from the guanine-cytosine base pair cause DNA subunit lesions
【24h】

(G-H)(center dot)-C and G-(C-H)(center dot) radicals derived from the guanine-cytosine base pair cause DNA subunit lesions

机译：

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

The radicals generated by the homolytic cleavage of an X-H bond from the guanine-cytosine (G(.)C) base pair were studied by using carefully calibrated theoretical methods. The gradient-corrected density functional B3LYP was applied in conjunction with double-zeta; plus polarization and diffuse function basis sets. Optimized geometries, energies, and vibrational frequencies were obtained for all of the radicals considered. Structural perturbations along with energy relaxation due to radical formation were investigated. Dissociation energies of the G(.)C base pair and all of the radicals are predicted and compared with the dissociation energy of neutral G(.)C. The three lowest-energy base pair radicals all involve removal of an H atom from one of the N atoms in G(.)C. The lowest-energy base pair radical has the hydrogen atom removed from the guanine nitrogen atom used for the sugar phosphate linkage in DNA. This (G-H)(BULL;)-C radical has a dissociation energy (to G-H-BULL; + C) of 30 kcal/mol, which may be compared with 27 kcal/mol for G(.)C. All of the radicals that are possible outcomes of direct ionizing radiation or oxidizing species were investigated for the presence of local minima with significant structural changes. Major structural deformations cause strain in the interstrand hydrogen bonding in the DNA double helix. Severe geometry changes were observed when the hydrogen was abstracted from interstrand hydrogen bonding sites, along with sizeable energy changes, indicating the potentially serious consequences to the G(.)C base pair.

著录项

相似文献

  • 外文文献
  • 中文文献
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