Linear B-cell epitope mapping using enzyme-linked immunosorbent assay for libraries of overlapping synthetic peptides

The aim of this chapter is to provide a strategy for mapping linear antibody epitopes of protein antigens in order to discover candidates for vaccines or diagnostic tests. A set of overlapping peptides was designed and synthesised based upon a known amino acid sequence of the target protein, virulence-associated protein A (VapA) of the bacterium Rhodococcus equi, an important pulmonary pathogen in foals.The peptides were biotinylated and used in an ELISA to screen immune sera from foals. These biotinylated peptides were coated directly onto micro titre plates that had been pre-coated with NeutrAvidin. A linear B-cell epitope was identified by a universal recognition of sera to the synthetic peptides which corresponds to a particular fragment of the VapA protein.