6,4,4′-Trimethylangelicin photoadduct immunodetection in DNA: induction and repair in Fanconi's anemia and normal human fibroblasts

摘要: Abstract 6,4,4′-Trimethylangelicin (TMA)-photoinduced monoadducts (MAs) were detected and quantified on DNA of normal human Fanconi's anemia (FA) fibroblasts (complementation groups A D) by immuno-electron microscopy. TMA-modified was extracted from the cells just after photoreaction, or a subsequent 24 h repair period, for analysis MA processing capabilities different cell lines. Unmodified control in parallel. The immunoreaction with antibody 7E3 performed single-stranded fragments obtained heat-formamide denaturation. On scanned electron microscope, IgG-labeled sites appeared as isolated clustered IgG molecules, which not homogeneously distributed. clusters (doublets, triplets near-neighbors (within distance 250 nucleotides)) measured separately induction frequency removal. Few interstrand cross-links (CLs) present X-shape fragments. At time zero, distribution patterns TMA-photoinduced CLs, their amount per 106 nucleotides, similar three After FA two genetic complementation demonstrated impaired incision-excision both MAs (singlets clusters) CLs when compared cells. In each line, relative proportions TMA-induced lesions remaining at to those initially induced. This implies analogous kinetics towards given line.