Epitope mapping and conformational analysis of SV40 T-antigen deletion mutants

Deletion mutants of SV40 T-antigen were stably expressed in BALB/c 3T3E cells and characterized in immunoprecipitation assays using T-antigen-specific monoclonal antibodies. The epitope recognized by antibody PAb602 was narrowed to T-antigen residues 230-362. Coprecipitation results were compatible with a p53-binding region between T-antigen amino acids 347 and 517. Amino terminal deletions (1-108 or 98-229) of T-antigen appeared to have pronounced effects on the conformation of distal regions of the molecule, based both on antibody binding and on association with p53.