Theoretical and experimental epitope mapping of thymosin beta 4

Two rabbit polyclonal antisera, one directed against thymosin beta 4 and the other one against the peptide fragment thymosin beta 4 (1-14) were characterised by epitope mapping. Hexapeptides representing the whole sequence of the native peptide and overlapping by one amino acid were synthesised on polystyrene pins. The antigenic determinants were identified in microtitre plates with an ELISA procedure. The polyclonal serum against thymosin beta 4 detected three epitopes (N-terminal, mid-region and C-terminal) whereas the polyclonal serum against the fragment contained only antibodies specific for the N-terminal epitope. These experimental results are consistent with theoretical predictions.