title: Tandem lesions and other products in X-irradiated DNA oligomers.
abstract: Free radicals interact with DNA bases to produce secondary radicals. The secondary radicals are reactive species and tend to interact with neighboring bases, resulting in DNA lesions with two adjacent modified bases. In this study the DNA oligomers d(CpApTpG) and d(CpGpTpA) were exposed to free radicals generated in anoxic aqueous solution by X irradiation. Four new lesions were identified in which adjacent guanine and pyrimidine bases are covalently bonded. One of the tandem lesions formed in d(CpGpTpA) has the C5 carbon atom of cytosine covalently bonded to the C8 carbon atom of guanine. Interestingly, the same bond is formed between the terminal bases in d(CpApTpG), resulting in a cyclized molecule.
authors.affiliation: Biophysics Department, Roswell Park Cancer Institute, Buffalo, New York 14263, USA.
authors.forename: H C
authors.initials: HC
authors.lastname: Box
authors.forename: E E
authors.initials: EE
authors.lastname: Budzinski
authors.forename: J B
authors.initials: JB
authors.lastname: Dawidzik
authors.forename: J C
authors.initials: JC
authors.lastname: Wallace
authors.forename: H
authors.initials: H
authors.lastname: Iijima
mesh_terms: D001704:Biopolymers / Q000737:chemistry / Q000528:radiation effects; D004247:DNA / Q000737:chemistry / Q000528:radiation effects*; D004249:DNA Damage; D005609:Free Radicals; D006147:Guanine / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D009690:Nucleic Acid Conformation; D011687:Purines / Q000737:chemistry; D013941:Thymine / Q000737:chemistry
chemical_list: D001704:Biopolymers; D005609:Free Radicals; D011687:Purines; D006147:Guanine; D004247:DNA; D013941:Thymine; C030985:purine