DETECTION OF ANTIGENIC DETERMINANTS IN THE TREPONEMA-PALLIDUM MEMBRANE-PROTEIN TMPA USING OVERLAPPING SYNTHETIC PEPTIDES

The antigenic structure of the 42 kDa membrane protein of Treponema Pa llidum, TmpA, was studied using synthetic peptides. Ten overlapping pe ptides, 35-40 residues each, were synthesized in order to cover the en tire sequence of the molecule. The antigenic activity of the fragments was examined by enzyme-linked immunosorbent assay (ELISA). In this wa y it was possible to demonstrate a significant antigenic activity of f our peptides which were reactive with syphilitic sera. The N-terminal fragment TmpA1, 38 residues long, proved to be the most reactive. Its antigenic structure was therefore studied in more detail, by examining shorter fragments. The N-terminal portion of TmpAl, consisting of 19 residues, (ASGAKEEAEKKAAEQRALL) represents an important fragment of th e molecule, and was specifically interactive with most of the syphilit ic sera examined.