在DNA中对瓜基离子的水合的机制方面
Yekaterina Rokhlenko1, Jean Cadet, Nicholas E Geacintov
1Chemistry Department, New York University , 31 Washington Place, New York, New York 10003-5180, United States.
Journal of the American Chemical Society
|April 3, 2014
概括
DNA的二次结构影响了瓜基的化. 双链DNA通过质子共享机制促进8-oxo-7,8-dihydroguanine (8-oxoG) 的形成,与单链DNA不同.
科学领域:
- 生物物理化学 生物物理化学
- 分子生物学分子生物学
- 频谱学是一种光谱学.
背景情况:
- 关氨酸基离子 (G(•+)) 是DNA损伤中的关键中间体.
- 了解它们的水化机制对于DNA修复和稳定性研究至关重要.
研究的目的:
- 为了研究在双链和单链DNA中瓜基的基离子水合的机械方面.
- 阐明DNA二次结构在8-oxo-7,8-dihydroguanine (8-oxoG) 的形成中的作用.
主要方法:
- 直接的时间分辨率光谱监测.
- 通过从S2O8(2-) 光解中通过SO4((•-) 基离子生成G.
- 激光脉冲在308nm. 在 308nm.
主要成果:
- 在中性DNA中,在SO4衰变后,中性瓜基 (G(-H)(•)) 具有312nm的λmax主导.
- 在DNA结构之间,衰变动力学显著不同:在双链DNA (ms和s组件) 中是双相的,在单链DNA (s组件) 中是单相的.
- 双链DNA显示了约7倍的8-oxoG产量,与ms衰变成分相关.
结论:
- 双链DNA的一个拟议机制涉及G(-H)(•) 在[G(•+):C]基对中与细胞素 (C) 共享一个质子,促进G(•+) 水和8-oxoG形成.
- 在单链DNA中,质子逃脱与水合相竞争,减少了8-oxoG产量.
- DNA二次结构关键调节瓜氧化和随后的损伤产物形成.
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