Mechanism of radiation-induced strand break formation in DNA and polynucleotides.
The present state of our knowledge of the OH radical-induced strand break (sb) formation in presence and absence of oxygen in aqueous solution is reviewed for poly(U), poly(C), poly(A) and single- and double-stranded DNA as substrates. It was shown earlier that a single OH radical can induce a double-strand break in DNA. As a key step in the mechanism an interstrand radical transfer is postulated. The OH radical reaction is part of the indirect effect of gamma-irradiation. In addition recent results are presented concerning sb formation by the direct effect of high-energy irradiation using laser-induced photoionization for the formation of radical cations.
Schulte-Frohlinde
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Max-Planck-Institut fur Strahlenchemie, Mulheim/Ruhr, FRG.
D004247:DNA / Q000737:chemistry* / Q000528:radiation effects; D004249:DNA Damage; D017665:Hydroxyl Radical; D007700:Kinetics; D007834:Lasers; D010100:Oxygen / Q000737:chemistry; D011061:Poly A / Q000737:chemistry / Q000528:radiation effects; D011066:Poly C / Q000737:chemistry / Q000528:radiation effects; D011072:Poly U / Q000737:chemistry* / Q000528:radiation effects; D013403:Sugar Phosphates / Q000737:chemistry; D014867:Water
D013403:Sugar Phosphates; D014867:Water; D011061:Poly A; D011072:Poly U; D011066:Poly C; D017665:Hydroxyl Radical; D004247:DNA; D010100:Oxygen