Figure 1
From: Rational Optimization of a Bispecific Ligand Trap Targeting EGF Receptor Family Ligands
(A) Schematics showing production of EGFR/Fc and HER3/Fc homodimers as well as EGFR:HER3 heterodimer by co-transfection of EGFR/Fc and HER3/Fc cDNA constructs into mammalian host cells.Conditioned medium harvested from the co-transfected cells were purified chromatographically to obtain the EGFR:HER3 heterodimer (see Methods for details). (B) Schematics showing the parental EGFR:HER3 heterodimer (RB200) and its derived mutants of RB222 and RB242 with the indicated amino acid substitutions. (C) High-affinity EGFR ligand binding is suppressed in the Fc-mediated EGFR:HER3 heterodimers. 125I-ligand binding was performed in anti-Fc–coated 96-well plates with the indicated purified EGFR:HER3 heterodimers immobilized on the surface. Shown are 125I-TGF-α binding (top), and 125I-NRG1-β binding (bottom). Results are means ± SEM of triplicate wells.