Plant-activation of the bicyclic aromatic amines benzidine and 4-aminobiphenyl.
Benzidine and 4-aminobiphenyl (4-ABP) are promutagenic bicyclic aromatic amines that are activated into frameshift and base pair substitution mutagens by plant systems. Using the plant cell/microbe coincubation assay, plant-activated benzidine from 0 to 50 microM induced a concentration-response in Salmonella typhimurium. At concentrations above 5 microM, plant-activated benzidine induced frameshift and base pair substitution mutations in the N- or O-acetyltransferase over-expressing strains, DJ460, YG1024, and YG1029. With plant-activated 4-ABP, concentrations above 250 microM induced a significant mutagenic response in strains YG1024 and YG1029. A tobacco cell-free mixture, TX1MX, activated benzidine and 4-ABP into mutagenic metabolites in S. typhimurium strains YG1024, YG1029, and DJ460. The mutagenic sensitivities of plant-activated benzidine and 4-ABP were the same with two different types of plant activation systems, TX1 suspension cells and TX1MX cell-free medium. The plant activation of these aromatic amines is mediated by tobacco cell peroxidase. Plant-activated benzidine and 4-ABP are converted into intermediates that serve as substrates for bacterial or humanacetylCoA: N-hydroxyarylamine N-acetyltransferase to generate the ultimate mutagenic products.
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Y H
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Department of Crop Sciences, University of Illinois at Urbana-Champaign, 61801-4723, USA.
Plewa
M J
MJ
D000123:Acetyltransferases; D000217:Acyltransferases / Q000378:metabolism; D000611:Aminobiphenyl Compounds / Q000378:metabolism* / Q000633:toxicity*; D000818:Animals; D000931:Antidotes / Q000494:pharmacology; D001191:Arylamine N-Acetyltransferase / Q000378:metabolism; D001560:Benzidines / Q000378:metabolism* / Q000633:toxicity*; D002248:Carbon Monoxide / Q000494:pharmacology; D002273:Carcinogens / Q000633:toxicity; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D018920:Coculture Techniques; D004050:Ditiocarb / Q000031:analogs & derivatives / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D008322:Mammals / Q000378:metabolism; D016296:Mutagenesis / Q000187:drug effects; D009152:Mutagenicity Tests / Q000379:methods; D009153:Mutagens / Q000378:metabolism / Q000633:toxicity; D010936:Plant Extracts / Q000378:metabolism; D010947:Plants, Toxic; D012486:Salmonella typhimurium / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity; D014026:Nicotiana / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*
D000611:Aminobiphenyl Compounds; D000931:Antidotes; D001560:Benzidines; D002273:Carcinogens; D009153:Mutagens; D010936:Plant Extracts; C006757:4-biphenylamine; C029876:benzidine; D002248:Carbon Monoxide; D004050:Ditiocarb; D000217:Acyltransferases; D000123:Acetyltransferases; C019736:N-hydroxyarylamine O-acetyltransferase; D001191:Arylamine N-Acetyltransferase; C039353:dihydroxyethyldithiocarbamate