空间损伤对称性对氧化B-DNA的结构反应的影响
Bahare Noohi1, Mansour Zahedi2
1Department of Computational and Physical Chemistry, Faculty of Chemistry and Petroleum Sciences, Shahid Beheshti University, Tehran, Iran. baharenoohi@gmail.com.
Scientific reports
|December 19, 2025
概括
氧化应激会产生像8-基-2'-脱氧氨酸 (8-基-dG) 这样的DNA病变,影响DNA结构. 损伤位置,而不仅仅是发生,显著改变了DNA的稳定性和功能,这对于理解突变发生和基因组不稳定性至关重要.
科学领域:
- 分子生物学分子生物学
- 生物物理学的生物物理.
- 计算化学计算化学
背景情况:
- 氧化和化应激是炎症和癌症组织的标志.
- 这些压力会产生反应性氧和物种,导致DNA损伤,特别是瓜宁转化为8-基-2-脱氧氨酸 (8-基-dG),这是致癌的关键因素.
- 虽然已知8-基-dG的生物学意义,但其对DNA的精确结构影响仍然不完全理解.
研究的目的:
- 通过反应分子动力学 (RMD) 模拟,研究各种关氨酸化方案对正规B-DNA的结构后果.
- 量化评估不同损伤位置和方向如何影响DNA的三维结构和稳定性.
主要方法:
- 在迪克森-德鲁十二摄像头DNA模型上使用反应分子动力学 (RMD) 模拟.
- 模拟了五种不同的基化方案:全球 (MtOH),现场参观 (MdOH,MlOH) 和取决于方向的终端 (Ml2r14OH,Ml2r24OH).
- 分析了五个螺旋变形描述符:基点对中心距离 (COBP),螺旋扭转角度 (PTA),全球/本地扭转角度 (GTA/LTA) 和端到端的DNA长度.
主要成果:
- 完全氧化DNA复合体表现出同位体延长和显著的解.
- 垂直导向的末端病变在很大程度上保留了原生螺旋结构.
- 病变位置横轴诱导端磨损和实质性的结构变化.
- 病变的位置对称性被确定为DNA稳定性的关键决定因素,比病变发生本身更重要.
结论:
- 8-基-dG病变的空间布局和对称性决定了DNA的结构完整性和稳定性.
- 这些发现提供了关于氧化应激如何导致突变发生和基因组不稳定性的机制性见解.
- 了解这些结构影响对于阐明与氧化应激相关的疾病中的病原遗传过程至关重要.
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