Antigen binding specificity of antibodies against 8-methoxypsoralen photoadducted DNA

The photoadduct between native DNA and 8-methoxypsoralen was characterized on the basis of UV and fluorescence characteristics, Tm, nuclease S 1 digestibility and hydroxyapatite column chromatography. Approximately 80% of photoadduct has at least one diadduct (crosslink) per DNA molecule and only thymine was modified to the extent of 69%. The photo-crosslink was highly immunogenic inducing antibodies having apparent association constant of 1.3 x 10(-9)M. The immune IgG was highly specific towards nucleic acid-furocoumarin crosslink site without appreciable recognition of B-conformation or nucleic acid bases. The antibodies could be used as probe to detect and quantitate nucleic acid modified with furocoumarins in health and disease.