CATIONIC ANTHRAQUINONE DERIVATIVES AS CATALYTIC DNA PHOTONUCLEASES - MECHANISMS FOR DNA-DAMAGE AND QUINONE RECYCLING
CATIONIC ANTHRAQUINONE DERIVATIVES AS CATALYTIC DNA PHOTONUCLEASES - MECHANISMS FOR DNA-DAMAGE AND QUINONE RECYCLING
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DOI：
10.1021/ja00101a005
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发表时间：
1994-11-02
影响因子：
15
通讯作者：
SCHUSTER, GB
中科院分区：
文献类型：
--
作者：
ARMITAGE, B;YU, CJ;SCHUSTER, GB
已经发现铵取代的蒽醌衍生物在用350 nm光照射时催化DNA裂解。皮秒激光光谱表明，激发的醌类与DNA反应的两个独立的氧化途径：电子转移从附近的基地和从脱氧核糖核酸骨架的组成部分的氢原子提取。通过任一途径的DNA的光氧化产生作为副产物的醌的单电子还原形式。从还原醌到氧化碱的反向电子转移是由电子转移途径形成的还原醌的主要衰变途径，而由氢原子提取形成的还原醌通过分子氧的还原被转换回基态、完全氧化的形式。通过其对细胞色素c的还原来检测所产生的超氧阴离子。比较具有显着不同切割效率的两种醌的光谱数据表明，这些醌试剂的DNA切割是由氢提取化学引起的。激光实验进一步表明，醌在10 μ s内完成了一个激发、DNA氧化和氧还原的循环，说明了这些试剂用于DNA双链切割的潜在用途。
Ammonium-substituted anthraquinone derivatives have been found to catalyze DNA cleavage upon irradiation with 350 nm light. Picosecond laser spectroscopy demonstrates that the excited quinones react with DNA by two separate oxidative pathways: electron transfer from a nearby base and hydrogen atom abstraction from the deoxyribose component of the nucleic acid backbone. Photo-oxidation of DNA by either pathway yields the one-electron-reduced form of the quinone as a byproduct. Back electron transfer from the reduced quinone to the oxidized base is the predominant decay path for the reduced quinone formed by the electron transfer pathway while that formed by hydrogen atom abstraction is converted back to the ground-state, fully oxidized form by reduction of molecular oxygen. The resulting superoxide anion is detected by its reduction of cytochrome c. Comparison of the spectroscopic data for two quinones with significantly different cleavage efficiencies suggests that DNA cleavage by these quinone reagents results from the hydrogen-abstraction chemistry. The laser experiments further indicate that the quinone completes one cycle of excitation, oxidation of DNA, and reduction of oxygen within 10 mu s, illustrating the potential utility of these agents for double-stranded cleavage of DNA.