TABLE 3.

Concentration-effect data for agonist stimulation of [³⁵S]GTPγS binding of WT and mutant receptors stably expressed in HEK293 cells

Data represent the mean of at least three independent experiments performed in triplicate. EC₅₀ values were determined from concentration-effect curves using GraphPad Prism software. The values in parentheses are 95% confidence intervals. Statistical analysis was performed by comparing the log EC₅₀ of the mutant receptor to the wild-type CB₁ receptors using a two-tailed Student’s t test to determine the level of significance.

	Drug	EC50 (95% CL)	Emax/Top (95% CL)	Mutant/WT EC50
WT	CP55,940	12.6 nM (3.6–43.7)	127% (109–145)	NA
	WIN55,212-2	36.7 nM (12.4–108.3)	95% (87–116)	NA
D2.63176A	CP55,940	67 nM (17–259)*	59% (48–71)*	5.3*
	WIN55,212-2	231 nM (27–1912)*	89% (60–118)	6.3*
K373A	CP55,940	70 nM (5.6–870)*	70% (44–100)	5.6*
	WIN55,212-2	274 nM (61–1230)*	83% (53–112)	7.5*
D2.63176A-K373A	CP55,940	39.8 nM (10–153)*	29% (23–35)*	3.2*
	WIN55,212-2	561 nM (60–5193)*	59% (38–81)*	15.3*
D2.63K-K373D	CP55,940	38 nM (6.9–209)	82% (73–93)	3
	WIN55,212-2	126 nM (26–607)	79% (63–95)	3.4

^*P < 0.05.