Figure 2.

Allosteric ternary complex model (ATCM). This model describes the interaction between orthosteric ligand A, and an allosteric modulator B, in terms of their respective equilibrium dissociation constants (K_A, K_B), and a cooperativity factor, α, that denotes the magnitude and direction of the allosteric effect on ligand binding affinity. This has been extended to include a proportionality factor, β, which accounts for allosteric effects of the modulator on orthosteric ligand intrinsic efficacy (May et al., 2007).