EPITOPE MAPPING OF ANTIBODIES RECOGNIZING THE N-TERMINAL DOMAIN OF SIMIAN-VIRUS LARGE TUMOR-ANTIGEN

The large tumour antigen (TAg) of simian virus 40 is the main regulato ry protein in viral replication. We have investigated possible functio nal roles for the N-terminal domain of TAg while defining the epitopes of antibodies binding within that region. The epitopes recognised by eight monoclonal anti-TAg antibodies were identified using synthetic p eptides in an enzyme-linked immunosorbent assay. For antibodies PAb 22 3, 281, 211, 219 and 224, epitopes varied in length between ten and fi fteen amino acids. Two antibodies, Phb 210 and PAb 419, could not be m apped any further using this technique. Antibody PAb 416 recognised a pentapeptide WEQWW that could be involved in topoisomerase I binding a nd possibly in the interaction between topoisomerase I and simian viru s reverse transcriptase.