DEVELOPMENT OF MONOCLONAL-ANTIBODIES SPECIFIC FOR 1,N-2-ETHENODEOXYGUANOSINE AND N-2,3-ETHENODEOXYGUANOSINE AND THEIR USE FOR QUANTITATION OF ADDUCTS IN G12-CELLS EXPOSED TO CHLOROACETALDEHYDE

Monoclonal antibodies specific for N2,3-ethenodeoxyguanosine (N2,3-epsilondGuo) and 1,N2-ethenodeoxyguanosine (1,N2-epsilondGuo) were developed. In a competitive ELISA, 50% inhibition of binding of the N2,3-epsilondGuo specific antibody (ETH1) was achieved with 18 fmol of N2,3-epsilondGuo. Fifty per cent inhibition of the 1,N2-epsilondGuo-specific antibody (ETH2) required 11 pmol 1,N2-epsilondGuo. Immunoassays for N 23-epsilondGuo and 1,N2-epsilondGuo in single-stranded DNA were developed using these antibodies. The immunoassays could detect as little as 48 fmol of N2 3-epsilondGuo or 340 fmol 1,N2-epsilondGuo in 25 mug of single stranded DNA. These assays and previously developed immunoassays for 1,N6-ethenodeoxyadenosine (1,N6-epsilondAdo) and 3,N4-ethenodeoxycytidine (3,N4-epsilondCyd) were used to measure etheno adduct levels in DNA of cells exposed to chloroacetaldehyde. The cells used were V79 cells with an inactivated hprt gene and a single copy of the bacterial gpt gene (G12 cells). The most abundant etheno adduct was 1,N6-epsilondAdo, followed by 3,N4-epsilondCyd and N2,3-epsilondGuo. 1,N2-epsilondGuo was not detected in chloroacetaldehyde-treated G12 cells. Chloroacetaldehyde was also shown to be mutagenic in these same cells.