Figure 2

(A) Ligand binding screening identifies EGFR/Fc and HER3/Fc mutants with enhanced affinity for EGF, TGF-α, HB-EGF, and NRG1-β. Screening was carried out in anti-Fc-coated 96-well plates as detailed in the Methods. Mutants with increased ligand binding from initial screening were selected for saturation binding to determine the apparent ligand binding affinity. Shown are mutants with affinity equal to or greater than two-fold of that of the Wt molecules. (B) Amino acid sequence alignments of HER family proteins reflecting the conserved residues of EGFR^T15 (top), HER3^Y246 (middle), and EGFR^G564 (bottom). Positions of the first aligned residues are shown in parentheses.