Selective Recognition of Substituted Chrysene-Diol Epoxide-2-DNA Adducts by Antiserum prepared Against DNA Adducts of Benzo[c]Phenanthrene-Diol Epoxide-2

Abstract

Polyclonal antiserum prepared against DNA that was modified with racemic benzo[c]phenanthrene-3,4-diol-1,2-epoxide-2 (B[c]PhDE-2; benzylic hydroxyl and epoxide oxygen trans) was characterized for specificity of antigen recognition. Previous studies have demonstrated that the antisera stereoselectively recognized B[c]PhDE-2-DNA and failed to recognize DNA modified with racemic benzo[c]phenanthrene-3,4-diol-1,2-epoxide-1 (B[c]PhDE-1-DNA, benzylic hydroxyl and epoxide oxygen cis), benzo[a]pyrene-7,8-diol-9, 10-epoxide-2-DNA (B[a]PDE-2-DNA) and 7,12-dimethylbenz[a]anthracene-3,4-diol-1,2-epoxide-1-DNA (DMBADE-1-DNA). DNA samples modified by diol-epoxide-2 diastereomers of several hydrocarbons were tested in competitive ELISA assays utilizing B[c]PhDE-2-DNA (270 fmol adducts per well). DNA modified with racemic diol-epoxide-2 of various substituted chrysenes (including chrysene, benzo[g]chrysene (B[g]C), 6-methylchrysene (6-MeC), and 5-methychrysene (5-MeC), gave 50% inhibition of antisera binding at significantly higher concentrations (5 to 7-fold) than the parent B[c]PhDE-2-DNA or 5,6-diMeCDE-DNA. DNA modified with 5,7-dimethylchryseneDE-2 (5,7-diMeCDE-2) and dibenzo[a,l]pyreneDE-2 (DB[a,l] PDE-2) required 20 and > 100-fold greater levels of adducts to give 50% inhibition. Results with B[c]Pb, 5,6-diMeC, chrysene, 6-MeC and 5-MeC diol epoxide-2-DNA