Radiation-induced formation of 2',3'-dideoxyribonucleosides in DNA: a potential signature of low-energy electrons.
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.
Department of Nuclear Medicine and Radiobiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada.
Guru S
GS
Madugundu
Yeunsoo
Y
Park
Léon
L
Sanche
J Richard
JR
Wagner
D004247:DNA / Q000737:chemistry*; D015224:Dideoxynucleosides / Q000138:chemical synthesis* / Q000737:chemistry; D004583:Electrons; D009690:Nucleic Acid Conformation
D015224:Dideoxynucleosides; D004247:DNA