Damage to Isolated DNA Mediated by Singlet Oxygen
Damage to Isolated DNA Mediated by Singlet Oxygen
复制标题
单线态氧介导的分离 DNA 损伤
DOI：
10.1002/1522-2675(20011219)84:12
复制
发表时间：
2001
影响因子：
1.8
通讯作者：
J. Cadet
中科院分区：
文献类型：
--
作者：
J. Ravanat;C. Saint;P. Mascio;G. Martinez;M. Medeiros;J. Cadet
在本工作中，我们研究了单线态氧（1 O2）与分离的DNA的反应。重点放在识别和定量测量的DNA修饰所产生的反应的1 O2与DNA。为此，小牛胸腺DNA与内过氧化物N，N′-二（2，3-二羟丙基）-1，4-萘二丙酰胺（1 O2的化学发生器）一起孵育。此后，消化DNA，并通过最近优化的高效液相色谱串联质谱测定法测量所得的氧化核苷。结果表明，在观察到的不同DNA损伤中，7，8-二氢-8-氧代-2 ′-脱氧鸟苷是1 O2介导的DNA损伤的主要产物。有趣的是，在用1 O2发生器处理DNA后，没有形成环丁烷嘧啶二聚体、氧化的嘧啶碱基、7，8-二氢-8-氧代-2 ′-脱氧腺苷和2，6-二氨基-5-甲酰胺基-4-羟基嘧啶，至少没有可检测的量。报道的结果有力地表明，内过氧化物的分解提供了1 O2的纯来源，1 O2与分离的DNA反应诱导特异性形成7，8-二氢-8-氧代-2 ′-脱氧鸟苷。
In the present work, we study the reaction of singlet oxygen (1O2) with isolated DNA. Emphasis is placed on the identification and quantitative measurement of the DNA modifications that are produced by the reaction of 1O2 with DNA. For this purpose, calf-thymus DNA was incubated with the endoperoxide of N,N′-di(2,3-dihydroxypropyl)-1,4-naphthalenedipropanamide, a chemical generator of 1O2. Thereafter, DNA was digested, and the resulting oxidized nucleosides were measured by means of a recently optimized high-performance-liquid-chromatography tandem-mass-spectrometry assay. It was found that, among the different DNA lesions observed, 7,8-dihydro-8-oxo-2′-deoxyguanosine is the major 1O2-mediated DNA-damage product. Interestingly, cyclobutane pyrimidine dimers, oxidized pyrimidine bases, 7,8-dihydro-8-oxo-2′-deoxyadenosine, and 2,6-diamino-5-formamido-4-hydroxypyrimidine are not formed, at least not in detectable amounts, following treatment of DNA with the 1O2 generator. The reported results strongly suggest that the decomposition of the endoperoxide provides a pure source of 1O2, and that reaction of 1O2 with isolated DNA induces the specific formation of 7,8-dihydro-8-oxo-2′-deoxyguanosine.