LINEAR ANTIGENIC SITES DEFINED BY THE B-CELL RESPONSE TO HUMAN P53 ARE LOCALIZED PREDOMINANTLY IN THE AMINO AND CARBOXY-TERMINI OF THE PROTEIN

Using a set of overlapping peptides of the human p53 protein, we analy sed the epitopes recognized by 18 monoclonal antibodies specific far h uman p53. We showed that most of these epitopes correspond to linear a ntigenic determinants which lie predominantly in the amino- or carboxy -terminus of the p53 protein. Using either truncated p53 or the set of human p53 peptides, we directly analysed the sera of animals immunize d with human p53, These sera contained antibodies which also recognize d the regions corresponding to the extremity of the p53 protein. These p53 regions were similar to those recognized by p53-specific antibodi es present in sera of patients with cancer. Preferential recognition o f these regions by antibodies specific for non conformational epitopes suggested that these regions are localized at the surface of the p53 protein as unfolded structures.