title: Aflatoxin B1 mutagenesis, DNA binding, and adduct formation in Salmonella typhimurium.
abstract: Salmonella typhimurium strain TM677 was mutagenized with aflatoxin B1 (AFB1) in liquid suspension culture in the presence of a rat liver postmitochondrial supernatant. Forward mutation to 8-azaguanine resistance was measured in the treated cultures and was found to increase linearly with AFB1 concentration. DNA purified from mutagenized cells was analyzed for AFB1 adduct formation by high-pressure liquid chromatography after adduct liberation. AFB1 exposures at 0.16 and 0.32 micrometer for 35 min produced 15 and 22 AFB1--DNA adducts per genome, respectively, and induced 8-azaguanine-resistant fractions of 4.9 X 10(-4) and 9.6 X 10(-4). Approximately 70% of the AFB1 bound to DNA was chromatographically identical to 2,3-dihydro-2-(N7-guanyl)-3-hydroxyaflatoxin B1 at the two AFB1 levels used.
mesh_terms: D000348:Aflatoxins / Q000378:metabolism / Q000494:pharmacology*; D000818:Animals; D004269:DNA, Bacterial / Q000378:metabolism*; D008862:Microsomes, Liver / Q000378:metabolism; D009154:Mutation / Q000187:drug effects*; D011485:Protein Binding; D051381:Rats; D012486:Salmonella typhimurium / Q000187:drug effects / Q000378:metabolism*
chemical_list: D000348:Aflatoxins; D004269:DNA, Bacterial