Figure 13.

Simulated relative response (“bias”) plots with the present model (Equation 38) for two pathways with different amplifications (γ ₁=10 and γ ₂=30) and for agonists A–D with efficacies ε ₁ and ε ₂ as indicated. Small circles along the lines indicate the responses corresponding to 50% occupancy (i.e., at ligand concentrations of K _d) to illustrate the mismatch between fractional responses and fractional occupancies along each pathway.