DNA oxidation

DNA oxidation is the process of oxidative damage of deoxyribonucleic acid. As described in detail by Burrows et al.,[1] 8-oxo-2'-deoxyguanosine (8-oxo-dG) is the most common oxidative lesion observed in duplex DNA because guanine has a lower one-electron reduction potential than the other nucleosides in DNA. The one electron reduction potentials of the nucleosides (in volts versus NHE) are guanine 1.29, adenine 1.42, cytosine 1.6 and thymine 1.7. About 1 in 40,000 guanines in the genome are present as 8-oxo-dG under normal conditions. This means that >30,000 8-oxo-dGs may exist at any given time in the genome of a human cell. Another product of DNA oxidation is 8-oxo-dA. 8-oxo-dA occurs at about 1/10 the frequency of 8-oxo-dG.[2] The reduction potential of guanine may be reduced by as much as 50%, depending on the particular neighboring nucleosides stacked next to it within DNA.

Excess DNA oxidation is linked to certain diseases and cancers,[3] while normal levels of oxidized nucleotides, due to normal levels of ROS, may be necessary for memory and learning.[4][5]

  1. ^ Burrows CJ, Muller JG (May 1998). "Oxidative Nucleobase Modifications Leading to Strand Scission". Chem. Rev. 98 (3): 1109–1152. doi:10.1021/cr960421s. PMID 11848927.
  2. ^ Cadet, Jean; Davies, Kelvin J.A.; Medeiros, Marisa HG; Di Mascio, Paolo; Wagner, J. Richard (June 2017). "Formation and repair of oxidatively generated damage in cellular DNA". Free Radical Biology and Medicine. 107: 13–34. doi:10.1016/j.freeradbiomed.2016.12.049. PMC 5457722. PMID 28057600.
  3. ^ Reuter S, Gupta SC, Chaturvedi MM, Aggarwal BB (December 2010). "Oxidative stress, inflammation, and cancer: how are they linked?". Free Radic. Biol. Med. 49 (11): 1603–16. doi:10.1016/j.freeradbiomed.2010.09.006. PMC 2990475. PMID 20840865.
  4. ^ Massaad CA, Klann E (May 2011). "Reactive oxygen species in the regulation of synaptic plasticity and memory". Antioxid. Redox Signal. 14 (10): 2013–54. doi:10.1089/ars.2010.3208. PMC 3078504. PMID 20649473.
  5. ^ Beckhauser TF, Francis-Oliveira J, De Pasquale R (2016). "Reactive Oxygen Species: Physiological and Physiopathological Effects on Synaptic Plasticity". J Exp Neurosci. 10 (Suppl 1): 23–48. doi:10.4137/JEN.S39887. PMC 5012454. PMID 27625575.