Figure 6.

Kinetics of fluorescent ligand 10a at D₃R and competition binding experiments. (a) Association of 10a at room temperature was measured by NanoBRET using secNluc-D₃R membrane preparations and threefold serial dilutions of 10a (3.3–30 nM). (b) Dissociation of 10a was initiated by addition of 10 μM haloperidol after equilibrium had been reached. Data show duplicates of an individual representative experiment. (c,d) Competition binding curves for reference antipsychotics obtained with (c) the radioligand [³H]spiperone and membranes from HEK293T cells expressing wtD₃R receptors or (d) 100 nM fluorescent ligand 10a and secNluc-D₃R membranes. Obtained IC₅₀ values were transformed into K_i values applying the equation of Cheng and Prusoff⁵². Data show mean ± SEM of n = 4 independent experiments.