Formation and 32P-postlabeling of DNA and tRNA adducts derived from peroxidative activation of carcinogenic azo dye N,N-dimethyl-4-aminoazobenzene.
Peroxidase in the presence of hydrogen peroxide catalyzes in vitro the activation of carcinogenic N,N-dimethyl-4-aminoazobenzene (DAB) to DNA-, tRNA- and homopolydeoxyribonucleotide-bound products. tRNA is the most susceptible to modification by the activated DAB. Binding of DAB products to macromolecules is inhibited by methyl viologen, nitrosobenzene, ascorbate, glutathione, NADH and MgCl2. The mechanism of these inhibitions was studied. The nuclease P1 version of the 32P-postlabeling assay was employed for detection and quantitation of some major DNA or tRNA adducts formed with DAB activated by a peroxidase system. tRNA modified by activated DAB shows a significantly increased acceptance for L-methionine.
Stiborová
M
M
Department of Biochemistry, Faculty of Natural Sciences, Charles University, Prague, Czechoslovakia.
Frei
E
E
Schmeiser
H H
HH
Wiessler
M
M
Hradec
J
J
D000818:Animals; D001345:Autoradiography; D001711:Biotransformation; D002273:Carcinogens / Q000493:pharmacokinetics / Q000633:toxicity*; D002417:Cattle; D002855:Chromatography, Thin Layer; D004247:DNA / Q000187:drug effects* / Q000378:metabolism; D016166:Free Radical Scavengers; D006861:Hydrogen Peroxide / Q000378:metabolism*; D008715:Methionine / Q000378:metabolism; D009243:NAD / Q000737:chemistry; D010084:Oxidation-Reduction; D010761:Phosphorus Radioisotopes; D012343:RNA, Transfer / Q000187:drug effects* / Q000378:metabolism; D004124:p-Dimethylaminoazobenzene / Q000493:pharmacokinetics / Q000633:toxicity*
D002273:Carcinogens; D016166:Free Radical Scavengers; D010761:Phosphorus Radioisotopes; D009243:NAD; D004247:DNA; D012343:RNA, Transfer; D004124:p-Dimethylaminoazobenzene; D008715:Methionine; D006861:Hydrogen Peroxide