Protein p53 Binding to Cisplatin-modified DNA Targets Evaluated by Modification-specific Electrochemical Immunoprecipitation Assay

Studies of protein interactions with chemically modified nucleic acids are of importance in various areas of biomolecular and biomedical research, including investigations of the binding of proteins important in medicine with DNA modified with drugs and diagnostic applications of modified DNAs in biosensing and bioanalysis. Chemical modification of DNA substrates with various species inside or outside specific protein binding sites can affect the protein-DNA recognition. In this paper we present a simple electrochemical immunoprecipitation technique designed for evaluation of the effects of antitumor drug cisplatin on the p53-DNA binding. The cisplatin-DNA adducts are utilized as electroactive labels allowing a facile determination of the p53-bound modified DNA. Effects observed using this technique accord with results of previous biochemical assays. This approach is potentially applicable in studies that deal with the influence of any electroactive DNA modifications on the protein-DNA binding.