Identification of peptides mimicking the natural epitope recognized by the CB-EGF1 anti-EGF monoclonal antibody

As part of an integral structure and function study, we characterized the natural epitope on the EGF recognized by the CB-EGF1 monoclonal antibody, by using peptides displayed on the coat protein of filamentous bacteriophages. Data analyzed demonstrated that the CB-EGF1 monoclonal antibody recognizes a conformational epitope, comprising aminoacids S9, H10, Y13, K28, E40 and R41. The identified peptide sequences are mimicking the region on the EGF interacting with the β-chain of the EGF receptor (EGFR). Synthetic peptides F22-54 and F22-55 compete with the EGF for binding to the CB-EGF1 antibody, as demonstrated by ELISA, but lacking biological activity in the EGF-EGFR system.