Interfacial properties of p53-DNA complexes containing various recognition elements

Abstrakt

Methods which can distinguish between specific and non-specific protein interactions leading to the identifica- tion ofhubs and nodes are still desired. This work shows utilization ofchronopotentiometric stripping analysis in combinationwith a mercury electrode in the study ofprotein-DNA interactions at thiol-modified electrodes. The complex of tumor suppressor p53 core domain (p53CD) and DNA undergoes disintegration due to the effect of the electric field, accompanied by a remarkable increase in the electrocatalytic reduction signal. By adjusting stripping current intensities and temperature, the transition between intact and disintegrated complex reflected differences in the stabilities of sequence-specific complexes with different recognition elements. Higher stabili- ties ofp53-DNA complexes were observed for DNA binding sites connected with cell-cycle arrest and p53 nega- tive autoregulation, than those for DNA associatedwith cell apoptosis, in good concordance with electrophoretic mobility shift assay in polyacrylamide gels. These data highlight the utility of this method for studying the dy- namics of surface-attached protein-DNA complexes.