DNA sequence context as a determinant of the quantity and chemistry of guanine oxidation produced by hydroxyl radicals and one-electron oxidants.

ABSTRACT: DNA sequence context has emerged as a critical determinant of the location and quantity of nucleobase damage caused by many oxidizing agents. However, the complexity of nucleobase and 2-deoxyribose damage caused by strong oxidants such as ionizing radiation and the Fenton chemistry of Fe2+-EDTA/H2O2 poses a challenge to defining the location of nucleobase damage and the effects of sequence context on damage chemistry in DNA. To address this problem, we developed a gel-based method that allows quantification of nucleobase damage in oxidized DNA by exploiting Escherichia coli exonuclease III to remove fragments containing direct strand breaks and abasic sites. The rigor of the method was verified in studies of guanine oxidation by photooxidized riboflavin and nitrosoperoxycarbonate, for whic

SUBMITTER: Margolin Y 

PROVIDER: S-EPMC2602890 | biostudies-literature | 2008 Dec

REPOSITORIES: biostudies-literature