Binding of rhTPO to recombinant c-Mpl (gD-Mpl). rhTPO was immobilized to a BiaCore sensor chip via a c-terminal carbohydrate group. The subsequent binding and dissociation of five different concentrations (500, 100, 50, 10, and 5 nmol/L) of gD-Mpl to the rhTPO was measured (represented by the 5 data curves). Binding constants were obtained from the slope of the plots versus time data using the BiaCore TM kinetics evaluation software.