Tandem lesions are the major products resulting from a pyrimidine nucleobase radical.
Nucleobase radicals (e.g., 1) are the major family of reactive intermediates formed when DNA is exposed to gamma-radiolysis. Independent generation of 1 in chemically synthesized oligonucleotides reveals that formation of this nucleobase radical under aerobic conditions results in the formation of tandem lesions approximately 65% of the time. The distribution of lesions formed with the 5'- and 3'-adjacent nucleotides is dependent upon the secondary structure of duplex DNA. Tandem lesions, which are defined as two contiguously, damaged nucleotides in a single DNA strand, are of significant biological interest. The yield of tandem lesions from 1 is much greater than was previously believed. The observations presented could have significant ramifications on how scientists interpret the effects of gamma-radiolysis on DNA.
Department of Chemistry, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, USA.
K Nolan
KN
Carter
Marc M
MM
Greenberg
D004249:DNA Damage; D008958:Models, Molecular; D011675:Pulse Radiolysis; D011741:Pyrimidine Nucleosides / Q000737:chemistry* / Q000528:radiation effects*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D011741:Pyrimidine Nucleosides