Splitting of cis-syn cyclobutane thymine-thymine dimers by radiolysis and its relevance to enzymatic photoreactivation.
The 137Cs-gamma-irradiation of cis-syn thymine-thymine cyclobutane type dimers has been studied in aqueous solution. The mechanism of thymine dimer cleavage by eaq-, CO2.-, OH.,SO4.-,Br2.- and isopropanol radicals was studied using high pressure liquid chromatography (HPLC). Evidence that the one-electron reductants studied induce dimer cleavage partially by a chain reaction is presented. Approximate values for the one-electron reduction potential of thymine-thymine are obtained and thermodynamic calculations are presented in order to predict the direction of electron transfer in the case of enzymatic photoreactivation.
Heelis
P F
PF
Faculty of Science, Health and Medical Studies, North East Wales Institute, Deeside, Clwyd, UK.
Deeble
D J
DJ
Kim
S T
ST
Sancar
A
A
D002588:Cesium Radioisotopes; D004255:Deoxyribodipyrimidine Photo-Lyase / Q000502:physiology*; D005720:Gamma Rays; D011740:Pyrimidine Dimers / Q000528:radiation effects*; D012996:Solutions; D014867:Water
D002588:Cesium Radioisotopes; D011740:Pyrimidine Dimers; D012996:Solutions; D014867:Water; D004255:Deoxyribodipyrimidine Photo-Lyase