EPITOPES OF AN INFLUENZA VIRAL PEPTIDE RECOGNIZED BY ANTIBODY AT SINGLE AMINO-ACID RESOLUTION

Abstract

Antibodies raised against the synthetic peptide corresponding to the carboxy-terminal 24 amino acids (305-328) of the heavy chain of the hemagglutinin molecule of influenza virus A/X-31 (H3) bind this peptide at three antigenic sites. These sites were identified by assaying binding of polyclonal BALB/c mouse antipeptide sera to the complete set of all possible di-, tri, tetra-, penta-, hexa-, hepta-, and octapeptides homologous with the 24-residue sequence. Individual epitopes were defined and essential residues identified by testing the binding of monoclonal antibodies to sets of peptide analogues in which every one of the homologous residues was replaced in turn by each of the 19 alternati..