title: Reactions induced in vitro between model DNA and benzo[a]pyrene by near-ultraviolet radiation.
abstract: Near-ultraviolet (300--480 nm wavelength) irradiation of the single-strand polydeoxynucleotide poly[d(A,C,G,T)] and carbon-14 labeled benzo[alpha]-pyrene (B[alpha] P) in aqueous dimethylsulfoxide (DMSO) solution led to appreciable binding of labeled hydrocarbon to the polynucleotide. Nuclease digests of polydeoxynucleotide-B[alpha]P complexes were examined by chromatography on Sephadex LH-20; at high fluences of near-ultraviolet light deoxyguanosine (dG) residues of the polymer were largely destroyed when the hydrocarbon was present. Approximately 85% of the B[alpha] P of the digests were recovered as hydrophilic derivatives not adsorbed by Sephadex LH-20. Elution of the columns with an aqueous-methanol gradient indicated that substances similar to the covalent deoxynucleoside-B[alpha] P adducts formed between microsomally-oxidized B[alpha] P and DNA were likewise present in the digests. When the deoxyadenosine (dA), deoxycytidine (dC) or dG moieties of the polymer were tritium-labeled, substances doubly-labeled with tritium and carbon-14 were found; ratios of the two radioactivities indicated that equimolar amounts of deoxynucleoside and hydrocarbon were present.
mesh_terms: D001564:Benzo(a)pyrene; D001580:Benzopyrenes / Q000378:metabolism / Q000528:radiation effects*; D002273:Carcinogens / Q000378:metabolism / Q000528:radiation effects*; D004247:DNA / Q000378:metabolism / Q000528:radiation effects*; D004277:DNA, Single-Stranded; D003849:Deoxyguanosine / Q000378:metabolism / Q000528:radiation effects; D011089:Polydeoxyribonucleotides; D014466:Ultraviolet Rays
chemical_list: D001580:Benzopyrenes; D002273:Carcinogens; D004277:DNA, Single-Stranded; D011089:Polydeoxyribonucleotides; C028826:poly(d(A,C,G,T)); D001564:Benzo(a)pyrene; D004247:DNA; D003849:Deoxyguanosine