Contribution of AB and AB* binding in 2-site model and Maximal binding response. (A) Simulation sensorgrams generated by the heterogeneous ligand model for GPRPFPAC. The combine response is a sum of analyte-ligand complexes AB and AB*. (B) Maximal binding response (resonance unit; RU) for the corresponding peptide concentration (molar, M). GPSPAAC, GPRPAAC, GPRPFPAC, GPRPPERC, GPRVVERC, and GPRVVAAC.