Mechanism of DNA damage by thiocyanate radicals.
Mechanism of DNA damage by thiocyanate radicals.
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硫氰酸盐自由基损伤 DNA 的机制。
DOI：
10.1080/09553000050151574
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发表时间：
2000
影响因子：
2.6
通讯作者：
Ward,JF
中科院分区：
文献类型：
--
作者：
Milligan,JR;Aguilera,JA;Paglinawan,RA;Ward,JF
目的先前的研究表明，γ辐照质粒DNA水溶液中存在毫摩尔浓度的硫氰酸盐离子，可导致碱基切除修复内切酶甲酰胺-嘧啶-DNA N -糖基化酶（FPG）识别的位点形成非常高产。作者希望描述负责产生这些fpga敏感位点的机制。材料与方法用137cs γ射线辐照含硫氰酸盐离子的质粒DNA水溶液。辐照后，等分液用FPG处理。用中性琼脂糖凝胶电泳法测定断裂率。结果随着酶活性的降低、硫氰酸盐浓度的增加、剂量率的增加、离子强度的增加、亚硝酸盐或碘化物浓度的增加和氧浓度的降低，fpga敏感位点的产率降低。结论硫氰酸单体自由基SCN•是该反应的中间产物，二聚体自由基阴离子（SCN） 2•-歧化和单电子氧化鸟嘌呤在DNA中的归宿竞争决定了fpg敏感位点的产率。后者可以与氧反应产生fpg敏位，也可以还原而不产生fpg敏位。这些结果有助于阐明电离辐射直接eÚect造成DNA损伤的机制。
PurposeIt was previously shown that γ-irradiation of aqueous solutions of plasmid DNA in the presence of millimolar concentrations of thiocyanate ions leads to the formation in very high yields of sites recognized by the base excision repair endonuclease formamido-pyrimidine-DNA N -glycosylase (FPG). The authors wished to characterize the mechanism responsible for the production of these FPG-sensitive sites.Materials and methodsAn aqueous solution of plasmid DNA containing thiocyanate ions was irradiated with 137 Cs γ-rays. After irradiation, aliquots were treated with FPG. Break yields were determined using neutral agarose gel electrophoresis.ResultsThe yield of FPG-sensitive sites decreased with decreasing enzyme activity, increasing thiocyanate concentration, increasing dose-rate, increasing ionic strength, increasing nitrite or iodide concentration, and decreasing oxygen concentration.ConclusionsThe observations suggest that the monomeric thiocyanate radical SCN •is an intermediate in the reaction, and that the yields of FPG-sensitive sites are determined by competition between the disproportionation of the dimeric radical anion (SCN) 2 •- and the fate of a one-electron oxidized guanine species in DNA. The latter can react with oxygen to produce an FPGsensitive site or can be reduced without producing an FPGsensitive site. The results help to clarify the mechanisms responsible for DNA damage by the direct eÚect of ionizing radiation.
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影响因子：
15
作者：
Melvin, T;Botchway, SW;ONeill, P
通讯作者：
ONeill, P
影响因子：
3.4
作者：
Milligan, JR;Ng, JYY;Cunningham, RP
通讯作者：
Cunningham, RP
重离子束 ([16]O[8]) 照射下 DNA 的电子自旋共振：脱氧核糖磷酸主链受损的证据。
DOI：
--
发表时间：
1996
期刊：
Radiation research.
影响因子：
--
作者：
Becker,D;Razskazovskii,Y;Callaghan,MU;Sevilla,MD
通讯作者：
Sevilla,MD
DNA 辐射损伤的化学后果
DOI：
10.1016/b978-0-12-035417-7.50006-4
发表时间：
1993
期刊：
Advances in radiation biology
影响因子：
--
作者：
D. Becker;M. Sevilla
通讯作者：
M. Sevilla
硫酸根阴离子诱导多核糖核苷酸和 DNA 链断裂：电子损失中心作为链断裂前体的作用。
影响因子：
2.6
作者：
P. Wolf;G. D. Jones;L. P. Candeias;P. O'Neill
通讯作者：
P. O'Neill