Biotin-Labeling of Poly(ADP-ribose) in Poly(ADP-ribose)-Protein Interactions

Methods are described for the preparation of poly(ADP-ribose) and for the preparation of biotinylated poly(ADP-ribose). Poly(ADP-ribose) is covalently modified to its biotinylated derivative by light-induced reaction of photobiotin with the polymer. Furthermore, conditions are given for the detection of poly(ADP-ribose) binding proteins in ligand-blotting experiments. The electrophoretically separated proteins are identified on blots using biotinylated poly(ADP-ribose) in a staining reaction. The results obtained with biotinylated poly(ADP-ribose) are comparable with those obtained with radioactive poly(ADP-ribose).