Fig. (4). Different conformations of the β₂ adrenergic receptor promoted by different agonists.

A table summarizing results from refs. [59, 60, 62] is shown. The structures of β₂ adrenergic receptor agonists are shown along with the traditional efficacy classification for those agonists. Agonist promoted conformational changes display two kinetic species, a slow phase and a rapid phase. The ability of each agonist to generate these two kinetic species is indicated. Changes are observed in two molecular switch regions in the receptor structure upon receptor activation. The ability of each agonist to generate a change in these molecular switch regions is indicated.