HYDROXYL FREE-RADICAL MEDIATED FORMATION OF 8-HYDROXYGUANINE IN ISOLATED DNA
HYDROXYL FREE-RADICAL MEDIATED FORMATION OF 8-HYDROXYGUANINE IN ISOLATED DNA
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DOI：
10.1016/0003-9861(88)90188-9
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发表时间：
1988-04-01
影响因子：
3.9
通讯作者：
TINGEY, DT
中科院分区：
文献类型：
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作者：
FLOYD, RA;WEST, MS;TINGEY, DT
研究了紫外线-H_2O_2作为羟基自由基产生体系照射小牛胸腺DNA后8-羟基鸟嘌呤的形成。使用高压液相色谱电化学检测，我们测量了酶消化的DNA中的8-羟基-2-脱氧鸟苷（8-OHdG）的量。DNA的8-OHdG含量随H_2O_2浓度的增加而线性增加，当H_2O_2浓度为0.03%时，增加速率小于线性。所有的羟基自由基清除剂的研究（甘露醇，乙醇，硫脲，水杨酸盐），如果存在于系统中，当DNA暴露于UV-H2 O2，导致形成的8-OHdG的量减少。当与受损的DNA孵育时，硫代嘌呤会导致8-OHdG的损失，而8-OHdG是DNA的组成部分。相反，硫脲不与溶液中游离的核苷反应。还原型谷胱甘肽不会导致8-OHdG的减少，无论是当它是DNA的一个组成部分，或作为游离核苷在溶液中。
Formation of 8-hydroxyguanine within calf thymus DNA has been studied after exposure to uv-H2O2 as a hydroxyl free radical generating system. Using high-pressure liquid chromatography with electrochemical detection, we measured the amount of 8-hydroxy-2-deoxyguanosine (8-OHdG) in the enzymatically digested DNA. The 8-OHdG content ofuv-exposed DNA increased linearly with increasing H2O2 levels up to 0.03%, above which the rate of increase was less than linear. All hydroxyl free radical scavengers studied (mannitol, ethanol, thiourea, and salicylate), if present in the system when DNA was exposed to uv-H2O2, caused a decrease in the amount of 8-OHdG formed. Thiourea when incubated with damaged DNA caused a loss of 8-OHdG when it was an integral part of DNA. In contrast, thiourea did not react with the nucleoside free in solution. Reduced glutathione did not cause a decrease of 8-OHdG, either when it was an integral part of DNA, or, as the free nucleoside in solution.