Reactivity of antibodies to guanosine modified by the carcinogen N-acetoxy-N-2-acetylaminofluorene.

N-(guanosin-8-yl) acetylaminofluorene (Guo-AAF) was prepared by the reaction of N-acetoxy-N-2-acetylaminofluorene (AAAF) and guanosine. Antibodies to Guo-AAF were elicited in rabbits by immunization with bovine serum albumin-Guo-AAF conjugate. The antibodies were purified by affinity chromatography on a Sepharose-Guo-AAF column. The reactivity of these antibodies towards several ligands was studied by radioimmunoassay. The antibodies have the same affinity for double stranded DNA-AAF and single stranded DNA-AAF. Thus the geometry of the regions of DNA substituted by AAF residues is the same in native and denatured DNA. The affinity of the antibodies is smaller for DNA-AAF than for Guo-AAF. This can be due in part to the stacking of AAF residues with the adjacent bases as shown by the study of the interactions between the antibodies and AAF-oligonucleotides. The circular dichroism spectra of AAF-oligonucleotides bound to the antibodies are reported.