酸素に依存しないDNAのインターストランド・クロスリンク形成は,核酸根によるものである
In Seok Hong1, Hui Ding, Marc M Greenberg
1Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, USA.
Journal of the American Chemical Society
|January 13, 2006
まとめ
研究者らは,鎖間クロスリンクを形成できる新しいDNAラジカルを生成した. この発見は,酸素不足の環境,例えば低酸素腫瘍における標的型DNA損傷の可能性を提供します.
科学分野:
- バイオケミストリー バイオケミストリー
- フォトケミストリー フォトケミストリー
- 分子生物学は分子生物学である.
背景:
- DNAの損傷と修復メカニズムは,細胞のプロセスにおいて極めて重要です.
- 光化学反応は,DNAに特定の改変を誘導することができます.
- 鎖間クロスリンク (ICL) は,治療上の意味を持つ重要なDNA病変である.
研究 の 目的:
- 新型5−2−デオキシウリジニル) メチルラジカル (1) の生成と性質を調査する.
- このラジカルによって誘発されるインターストランドクロスリンク形成のメカニズムを決定する.
- 治療戦略における酸素依存のクロスリンクの潜在的応用を探求する.
主な方法:
- 3つの異なる光化学的前駆体から (1) 基子の生成.
- ラジカル形成経路を明らかにするための酸素ラベル付け実験.
- 酸素とグルタチオンとのラジカル (1) の反応を理解するための運動分析.
- 糸間クロスリンク形成と可逆性の調査.
主要な成果:
- ラジカル (1) は,すべての前駆体から成功裏に生成され,鎖間クロスリンクを形成することが示された最初のDNAラジカルです.
- クロスリンクは2'-デオキシアデノシンとの反応によって発生し,分子酸素 (O(2) に依存しない.
- 動力学的研究は,可逆的な急性酸素反応を明らかにし,酸素の独立性を説明しました.
- グルタチオンの実験は,シンコンフォーマーションの採用が速度を制限することを示唆しており,クロスリンクは核愛性で逆転可能である.
- 隔離されたクロスリンクは,再配置の産物であり,溶液でもゆっくりと起こるプロセスです.
結論:
- 酸素に依存しないインターストランドクロスリンクを形成できる新しいDNAラジカルが特徴付けられました.
- この発見は,DNAの根性化学とクロスリンク形成のメカニズムについての洞察を提供します.
- 酸素に依存しないクロスリンクは,低酸素腫瘍細胞におけるDNA損傷の潜在的な戦略である.
さらに関連する動画
12:15Quantification of three DNA Lesions by Mass Spectrometry and Assessment of Their Levels in Tissues of Mice Exposed to Ambient Fine Particulate Matter
Published on: May 29, 2019
10:12Quantitative Detection of DNA-Protein Crosslinks and Their Post-Translational Modifications
Published on: April 21, 2023
関連する概念動画
Spontaneous and Induced Mutations
Spontaneous mutations arise infrequently during DNA replication due to errors in the process. A key factor behind these errors is tautomeric shifts in nitrogenous bases, where bases transition from keto to enol forms or amino to imino forms. This shift can alter base-pairing rules, leading to mutations. Additionally, reactive oxygen species (ROS) arising from aerobic metabolism can damage DNA, resulting in depurination (loss of a purine base) or depyrimidination (loss of a pyrimidine base).
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...
Homologous Recombination
The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the...
Radical Formation: Overview
A bond can be broken either by heterolytic bond cleavage to form ions or homolytic bond cleavage to yield radicals. A fishhook arrow is used to represent the motion of a single electron in homolytic bond cleavage. There are two main sources from which radicals can be formed:
Radicals from spin-paired molecules:
Radicals can be obtained from spin-paired molecules either by homolysis or electron transfer. While two radicals are formed in the former, an electron is added in the latter, also known...
Radicals from spin-paired molecules:
Radicals can be obtained from spin-paired molecules either by homolysis or electron transfer. While two radicals are formed in the former, an electron is added in the latter, also known...
Nucleotide Excision Repair
Overview
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...
