Department of Nuclear Medicine and Radiobiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada.
J Am Chem Soc. 2012 Oct 24;134(42):17366-8. doi: 10.1021/ja306810w. Epub 2012 Oct 15.
We have identified a series of modifications of the 2'-deoxyribose moiety of DNA arising from the exposure of isolated and cellular DNA to ionizing radiation. The modifications consist of 2',3'-dideoxyribonucleoside derivatives of T, C, A, and G, as identified by enzymatic digestion and LC-MS/MS. Under dry conditions, the yield of these products was 6- to 44-fold lower than the yield of 8-oxo-7,8-dihydroguanine. We propose that 2',3'-dideoxyribonucleosides are generated from the reaction of low-energy electrons with DNA, leading to cleavage of the C3'-O bond and formation of the corresponding C3'-deoxyribose radical.
我们已经鉴定出一系列由游离及细胞内 DNA 暴露于电离辐射而产生的 2'-脱氧核糖结构修饰。这些修饰物由 T、C、A 和 G 的 2',3'-二脱氧核苷衍生物组成，通过酶消化和 LC-MS/MS 鉴定。在干燥条件下，这些产物的产率比 8-氧代-7,8-二氢鸟嘌呤的产率低 6 至 44 倍。我们提出，2',3'-二脱氧核苷是由低能电子与 DNA 反应生成的，导致 C3'-O 键断裂并形成相应的 C3'-脱氧核糖自由基。
