Double lesions are produced in DNA oligomer by ionizing radiation and by metal-catalyzed H2O2 reactions

It was demonstrated previously that double lesions are produced in DNA by ionizing radiation. These double lesions consist of adjacent nucleotides each bearing a modified base. The goal of the present investigation was to determine whether Fenton chemistry can generate the same kind of lesions. DNA oligomers were exposed to metal-catalyzed H(2)O(2) reactions, and the products were characterized by chromatography and by mass spectrometry. Double lesions are produced by this treatment in which deoxyguanosine is oxidized to 8-oxo-7,8-dihydrodeoxyguanosine and an adjacent pyrimidine nucleoside is degraded to a formamido remnant.