Production and evaluation of polyclonal rabbit anti-human p53 antibody using bacterially expressed glutathione S-transferase-p53 fusion protein

p53 is a key tumor suppressor gene that is targeted for inactivation during human tumorigenesis. In this study, we produced and characterized polyclonal anti-human p53 antibody. The cDNA encoding the complete human p53 protein was cloned into pGEX-4T-1 and expressed in Escherichia coli as a fusion protein with Schistosoma japonicum glutathione S-transferase (GST). The rabbits were immunized with the purified p53 recombinant protein. The obtained antisera were purified to increase the specificity of recognition. The sensitivity and specificity of the produced antibody was analyzed by enzyme-linked immunosorbent, immunoblot, immunofluorescence and chromatin immunoprecipitation assays. Enzyme-linked immunosorbent assay showed that immunization with purified GST-p53 produced the high titer (1:10000) polyclonal antibodies with high specificity. Anti-p53 antibody allowed the sensitive detection of native p53 protein in immunoblotting, immunofluorescence and chromatin immunoprecipitation assays. Our results showed that anti-GST-p53 antibody provides a good means for studying the p53 expression pattern and its binding ability to other proteins in tumors.