Oxidative damage to DNA constituents by iron-mediated Fenton reactions - The deoxyguanosine family
Oxidative damage to DNA constituents by iron-mediated Fenton reactions - The deoxyguanosine family
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DOI：
10.1074/jbc.271.35.21177
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发表时间：
1996-08-30
影响因子：
4.8
通讯作者：
Linn, S
中科院分区：
文献类型：
--
作者：
Henle, ES;Luo, YZ;Linn, S
2‘-脱氧鸟苷、3’-dGMP、5‘-dGMP、d-GPG或双链DNA在厌氧条件下暴露于含Fe2+的H_2O_2中，或在有氧条件下暴露于Fe3+、Fe2+、Fe2+/NADH或Fe3+/NADH加或不加乙醇的条件下。产物用酶法消化成核苷，经高效液相色谱分离、定量，并用高效液相色谱保留时间、放射性标记、紫外吸收光谱、核磁共振、质谱学等方法进行表征。从Fe2+/H_2O_2与DG和dGMP的好氧反应中可区分出20种产物，占损伤的78-81%，其中16种被鉴定。DG、3‘-dGMP和5’-dGMP的产物光谱不同，d-GPG的5‘核苷的光谱不同于3’核苷，7，8-二氢-8-氧-2‘-脱氧鸟苷是除碱基以外最丰富的DNA结合产物，并对其形成进行了更详细的分析。NADH可以还原Fe3+，乙醇可以清除某些自由基，改变产物谱，NADH的损伤增强顺序为dg<；d-GPG<；3‘-dGMP<；5’-dGMP<；DNA；乙醇猝灭时观察到相反的顺序，这种敏感性顺序和3‘和5’磷酸的产物差异可能反映了铁的定位和底物上的损伤自由基。
2'-Deoxyguanosine, 3'-dGMP, 5'-dGMP, d-GpG, or double-stranded DNA were exposed to H2O2 in the presence of Fe2+ under anaerobic conditions or under aerobic conditions in the presence of Fe3+, Fe2+, Fe2+/NADH, or Fe3+/NADH with and without ethanol. The products were enzymatically digested to nucleosides, separated by high performance liquid chromatography (HPLC), quantified, and characterized by HPLC retention time, radiolabeling, UV absorbance spectrometry, NMR, and mass spectrometry. 20 products, constituting 78-81% of the damage, were distinguished from aerobic reactions of Fe2+/H2O2 with dG and dGMP, 16 of which were identified. The product spectra from dG, 3'-dGMP, and 5'-dGMP differ from one another, and the spectrum of the 5' nucleoside of d-GpG differs from that of the 3' nucleoside, 7,8-Dihydro-8-oxo-2'-deoxyguanosine is the most abundant DNA-bound product aside from abasic sites, and its formation was more closely analyzed. Both NADH, which can reduce Fe3+, and ethanol, which can scavenge some free radicals, change the product profiles, Damage enhancement by NADH follows the sequence dG < d-GpG < 3'-dGMP < 5'-dGMP < DNA; the reverse sequence is observed for ethanol quenching, This sequence of susceptibility and the product differences seen for the 3' and 5' phosphate may reflect localization of iron and the damaging radicals upon the substrate.