| Abstract: | DNA binding activity of rabbit antiserum against calf spleen DNA's modified by thiophosphamide (DNA-T) was studied by means of solid enzyme immunoassays (ELISA). The studies demonstrated the preferential binding of the immobilized DNA-T compared to immobilized single-stranded DNA (ss-DNA) and only small preference compared to native DNA. Two antisera against DNA-T were purified by affinity chromatography on a ss-DNA-CNBr agarose from antibodies to calf spleen ss-DNA. They interacted only with the immobilized DNA-T, but not with ss-DNA or native DNA. These results demonstrated that DNA modification by thiophosphamide, decreases the immunogenicity of usual nitrogen-containing DNA bases, but detected new immunogenic specificity for adducts. Detection of new immunogenic specificity in DNA's alkylated by thiophosphamide, resulted in the development of a sensitive enzyme immunoassay for the detection of these adducts in nucleic acids, in monitoring their formation, persistence and repair damages in DNA. |
