Enhancement of DNA binding and mutagenicity of 1-nitropyrene by zinc acetate in Salmonella typhimurium TA100.
The effect of zinc acetate on the mutagenicity of 1-nitropyrene (1-NP) in Salmonella typhimurium TA100 was examined. By the pre-treatment of the cells with zinc ions (0.24 mM) the revertant colonies caused by 1.5 microM of 1-NP in the pre-incubation mixtures increased approximately 3-fold, while the survival colonies decreased to approximately 75% under the same conditions. The enhancing effect of zinc ions on the mutagenicity was not dependent on the increase of 1-NP incorporation into the cells. The addition of zinc ions to whole cell preparations had no enhancing effect on the 1-NP reductase activity. The effect of zinc acetate on the binding of [3H]1-NP to DNA in S. typhimurium TA100 was examined. The amount of [3H]1-NP bound to DNA increased by the pre-treatment of the cells with zinc ions. A good correlation was found between the extent of binding of 1-NP to DNA and the frequency of induced histidine reversions in the cells treated with zinc ions under the experimental conditions used.
D000085:Acetates / Q000378:metabolism / Q000494:pharmacology* / Q000633:toxicity; D019342:Acetic Acid; D002850:Chromatography, Gel; D004269:DNA, Bacterial / Q000378:metabolism*; D009153:Mutagens / Q000378:metabolism*; D009601:Nitroreductases; D010088:Oxidoreductases / Q000032:analysis; D011485:Protein Binding / Q000187:drug effects; D011721:Pyrenes / Q000378:metabolism* / Q000633:toxicity; D012486:Salmonella typhimurium / Q000187:drug effects*; D014316:Tritium
D000085:Acetates; D004269:DNA, Bacterial; D009153:Mutagens; D011721:Pyrenes; D014316:Tritium; D010088:Oxidoreductases; C037214:1-nitropyrene reductase; D009601:Nitroreductases; D019342:Acetic Acid; C032668:1-nitropyrene