Effect of NH
OH and HgCl2 on the stability of the ADP-ribose bond. C-33A cells (1 × 107/ml) transfected with the chicken ART4 containing plasmid were incubated at 37°C in the presence or absence of 200 μM etheno-NAD+ for 30 min. After washing, cells were lysed and either directly precipitated (lane 1) or incubated at 37°C in the presence of 1 M NaCl (lane 2), 1 M NH2OH (pH 7.0) (lane 3) or 10 mM HgCl2 (lane 4). After 2 h proteins were precipitated with methanol. All samples were subjected to Western blot analysis using the etheno-adenosine specific antibody (A). After stripping, the blot was reprobed with a beta-actin specific antibody (B). Similar results were obtained in three separate experiments.