ANTIGEN-BINDING SPECIFICITY OF ANTIBODIES AGAINST 8-METHOXYPSORALEN PHOTOADDUCTED DNA

The photoadduct between native DNA and 8-methoxypsoralen was character ized on the basis of UV and fluorescence characteristics, Tm, nuclease S1 digestibility and hydroxyapatite column chromatography. Approximat ely 80% of photoadduct has at least one diadduct (crosslink) per DNA m olecule and only thymine was modified to the extent of 69%. The photo- crosslink was highly immunogenic inducing antibodies having apparent a ssociation constant of 1.3 x 10(-9)M. The immune IgG was highly specif ic towards nucleic acid-furocoumarin crosslink site without appreciabl e 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.