Selective modification of nuclear proteins by polycyclic aromatic hydrocarbons and by benzo[a]pyrene diol epoxides.
Metabolites of benzo[a]pyrene (B[a]P) have been shown to modify chromosomal proteins with great specificity. Using the (+) and (-) enantiomers of anti-B[a]P diol epoxide to label isolated nuclei we found a remarkable difference in the capacity of these two compounds to modify histones H2A and H3. The (+) enantiomer modified histones H2A and H3, while the (-) enantiomer, which was shown to modify mainly histone H2A, had a much lower affinity for histone H3. We have also examined the selective, modification of chromosomal proteins by different polycyclic aromatic hydrocarbons and it was observed that 7,12-dimethylbenz[a]-anthracene (DMBA), 3-methylcholanthrene (3-MC) and B[a]P showed qualitative similarities in terms of their protein binding. This suggests that stereospecific interactions leading to binding of reactive metabolites of DMBA, B[a]P and 3-MC to chromosomal proteins share common features.
D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide; D000818:Animals; D001580:Benzopyrenes / Q000494:pharmacology*; D002478:Cells, Cultured; D002875:Chromosomes / Q000378:metabolism; D006224:Cricetinae; D004622:Embryo, Mammalian; D008647:Mesocricetus; D009698:Nucleoproteins / Q000378:metabolism*; D011083:Polycyclic Compounds / Q000494:pharmacology*
D001580:Benzopyrenes; D009698:Nucleoproteins; D011083:Polycyclic Compounds; D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide