Fig. 5. Monitoring interactions between the CT and the cytoplasmic surface with a fluorescent probe bound to C378.

a Model of bimane labeled β₂AR-CT and CT at C378. The orthosteric ligand used in this experiment is isoproterenol, and the allosteric ligand is cmpd-6. b Increasing concentrations of Nb6B9 in combination with saturating isoproterenol result in a decrease in the bimane intensity of the β₂AR-CT, suggesting that the fluorophore moves to a more polar environment. c Increasing sodium chloride concentrations decrease bimane intensity in the apo β₂AR-CT. d The effect of sodium chloride concentration on bimane-labeled CT. e Increasing concentrations of the cmpd-6 combined with saturating isoproterenol result in a decrease in the bimane intensity of the β₂AR-CT. f The effect of cmpd-6 concentrations on bimane-labeled CT. g Nucleotide-free Gs reduces the bimane intensity of the β₂AR-CT. h Gs doesn’t affect the intensity of bimane-labeled CT.