Figure 4

Binding of hDM-αH-C6.5 MH3B1 to ECD^HER2. (A), Interaction of ECD^HER2 with hDM-αH-C6.5 MH3B1 immobilized on the surface of a SPR chip. ECD^HER2 at concentrations of a) 100 nM in duplicate b) 50 nM in duplicate c) 40 nM d) 20 nM in duplicate or e) 10 nM was flowed across the sensor chip at 30 μl/min for 750 second. f) Binding of 100 nM ECD^HER2 to immobilized hDM-αH-C6.5 MH3B1 after incubation with 1 μM hDM-αH-C6.5 MH3B1. (B), Binding of biotinylated hDM-αH-C6.5 MH3B1 to ECD^HER2 expressed on the cell surface. Bound protein was detected using Streptavidin-PE. Left panel shows binding of 0.5 μg of biotinylated hDM-αH-C6.5 MH3B1 to CT26HER2/neu and not to the parental cells that lack HER2/neu expression. Right panel shows binding of 0.1 μg (heavy green), or 0.5 μg of biotinylated hDM-αH-C6.5 MH3B1 (thin blue) or Streptavidin-PE (heavy black) to MCF-7HER2 cells. Filled are unstained cells.