5,6-Dimethylchrysene-1,2-Diol-3,4-Epoxide DNA Adducts are Stereoselectively Detected by Antisera Prepared Against the DNA Adducts Formed by the Stereoisomers of Benzo[c]phenanthrene-3,4-Diol-1,2-Epoxide

Abstract

Diastereomeric benzo[c]phenanthrene-3,4-diol-1,2-epoxides (B[c]PhDE)-1 and -2 (with the benzylic hydroxyl and epoxide oxygen cis and trans, respectively) are nonplanar polycyclic aromatic hydrocarbons (PAH) with sterically congested fjord regions. Polyclonal antibodies developed against DNA modified with B[c]PhDE-1 or B[c]PhDE-2 exhibited selective recognition of B[c]PhDE-DNA adducts and no cross-reactivity with DNA modified with benzo[a]pyrene-7,8-diol-9,10-epoxide. To determine if these antisera recognize DNA adducts formed by other PAH diol epoxides with sterically congested bay regions, 5-6-dimethylchrysene-1,2-diol-3,4-epoxide (5,6-diMeCDE)-1 or -2 modified DNA were tested in competitive ELISA assays. 5,6-diMeCDE-2-DNA gave 50% inhibition at 270 fmol of adducts/well with B[c]PhDE-2-DNA (160 fmol adducts/well) and its antiserum, but 5,6-diMeCDE-1-DNA was not an effective competitor. Neither 5,6-diMeCDE-1-DNA nor 5,6-diMeCDE-2-DNA was an effective competitor for B[c]PhDE-1-DNA and its antiserum. The antiserum against B[c]PhDE-1-DNA may be useful for studying DNA adducts from isomer 2 diol epoxides of PAH with sterically hindered bay regions.

Key Words:

• benzo[c]phenanthrene
• 5,6-dimethylchrysene
• polyclonal antibodies
• ELISA
• DNA adduct antibodies
• diol epoxide-DNA adducts