低能电子诱导的DNA损伤:终端酸盐和基团对损伤分布的影响
Zejun Li1, Yi Zheng, Pierre Cloutier
1Department of Nuclear Medicine and Radiobiology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, Québec, Canada J1H 5N4.
Journal of the American Chemical Society
|April 5, 2008
概括
低能电子 (LEE) 会导致DNA受损. 终端酸盐和基团影响损伤分布,酸盐增加了整体损伤,但减少了键断裂,终端基层屏蔽了内部基层.
科学领域:
- 生物物理学的生物物理.
- 化学生物学 化学生物学
- 辐射化学 辐射化学
背景情况:
- 低能电子 (LEE) 通过解离性电子附着诱导DNA损伤.
- 这一过程涉及关键的键键断裂,包括N-糖 (N-C) 键断裂用于释和糖 (C-O) 键断裂用于链断裂.
研究的目的:
- 研究终端酸盐和基部分对LEE诱导的DNA损伤的影响.
- 阐明这些末端组如何影响DNA损伤的部位和程度.
主要方法:
- 在凝结阶段,DNA模型化合物 (单体和二体) 暴露于LEE.
- 使用具有紫外线检测 (HPLC-UV) 的高性能液态色谱来分析由此产生的损伤产品.
主要成果:
- 终端酸盐组增加了2-3倍的整体DNA损伤.
- 然而,终端酸盐降低了N-C和C-O键裂变的2-10倍,表明它们没有直接调解这些裂变.
- 终端基地保护内部基地免受LEE引起的损伤,将损伤集中到DNA终端.
结论:
- 终端酸盐和基部分显著改变了LEE诱导的DNA损伤的分布.
- 这些发现表明,电子捕获,分子结构和DNA损伤机制之间存在复杂的相互作用.
相关概念视频
Overview of DNA Repair
In order to be passed through generations, genomic DNA must be undamaged and error-free. However, every day, DNA in a cell undergoes several thousand to a million damaging events by natural causes and external factors. Ionizing radiation such as UV rays, free radicals produced during cellular respiration, and hydrolytic damage from metabolic reactions can alter the structure of DNA. Damages caused include single-base alteration, base dimerization, chain breaks, and cross-linkage.
Chemically...
Chemically...
Long-patch Base Excision Repair
Since the discovery of the two BER pathways, there has been a debate about how a cell chooses one pathway over the other and the factors determining this selection. Numerous in vitro experiments have pointed out multiple determinants for the sub-pathway selection. These are:
Base Excision Repair
One of the common DNA damages is the chemical alteration of single bases by alkylation, oxidation, or deamination. The altered bases cause mispairing and strand breakage during replication. This type of damage causes minimal change to the DNA double helix structure and can be repaired by the base excision repair (BER) pathways. BER corrects damaged DNA sequences by removing the damaged base and restoring the original base sequence using the complementary strand as a template.
The first step of...
The first step of...
Base Excision Repair
One of the common DNA damages is the chemical alteration of single bases by alkylation, oxidation, or deamination. The altered bases cause mispairing and strand breakage during replication. This type of damage causes minimal change to the DNA double helix structure and can be repaired by the base excision repair (BER) pathways. BER corrects damaged DNA sequences by removing the damaged base and restoring the original base sequence using the complementary strand as a template.
The first step of...
The first step of...
Nucleotide Excision Repair
DNA Distortion and Damage
Cells are regularly exposed to mutagens—factors in the environment that can damage DNA and generate mutations. UV radiation is one of the most common mutagens and is estimated to introduce a significant number of changes in DNA. These include bends or kinks in the structure, which can block DNA replication or transcription. If these errors are not fixed, the damage can cause mutations, which in turn can result in cancer or disease depending on which sequences are...
Cells are regularly exposed to mutagens—factors in the environment that can damage DNA and generate mutations. UV radiation is one of the most common mutagens and is estimated to introduce a significant number of changes in DNA. These include bends or kinks in the structure, which can block DNA replication or transcription. If these errors are not fixed, the damage can cause mutations, which in turn can result in cancer or disease depending on which sequences are...
Nucleotide Excision Repair
Overview

