Figure 1.

Extended ternary complex model. The model is shown for a receptor existing in ground (R), partially activated (R^*) and fully active, G-protein-coupled states (R^*G). The equilibrium constants governing the R/R^* and R^*/R^*G transitions are L and J, respectively. The equilibrium constants for agonist binding to R, R^* and R^*G are K_R, K_R^* and K_R^*G, respectively.