Fate of DNA Sugar Radicals Chapter (Faculty180)

cited authors

  • Bryant-Friedrich, Amanda C

description

  • Oxidative damage to nucleic acids occurs at the nucleobase and at the sugar-phosphate backbone. While base damage dominates in frequency, the attack of oxidants at sugars in the nucleic acid backbone often leads to strand breaks that ultimately leave gaps or nicks that carry modified or “dirty” ends. When the damage is focused on the 2'-deoxyribose component of DNA, hydrogen atoms are abstracted from one of the five unique carbons of the pentose ring to deliver a highly reactive radical intermediate. Another important factor, which should be considered while attempting to make such predictions, is the identity of the oxidant. One of the most significant species to consider when discussing DNA oxidants is the hydroxyl radical. This reactive oxygen species is produced endogenously through cellular metabolism, at higher levels under conditions of oxidative stress, as a part of chronic inflammation and as a major outcome of the exposure of cells to ionizing radiation. The hydroxyl radical is small, highly diffusible, reactive, and capable of hydrogen atom abstraction at any position of 2'-deoxyribose moiety in DNA. Finally, the position of the C'5-radical relative to the nucleobase of DNA renders its reactivity toward the heterocyclic nucleic acid moieties very distinct as compared to the four other positions.

publication date

  • 2010

publisher

published in

start page

  • 127

end page

  • 155