Fig. (3).

Effects of different modulators on agonist response according to the model depicted in Fig. (2). Changes in affinity (α) only produce changes in the location parameter of the concentration-response curves but no change in maxima. Modulator-induced changes in efficacy (ξ) can alter location parameters and maximal response. For allosteric potentiation of response, only changes in location are observed for full agonists For partial agonists, changes in maxima can be seen. In cases of allosteric reduction in efficacy, both changes in location and maxima may be observed.