TABLE 1.

EC₅₀ values and ligand binding affinities for various α4β2 nAChR constructs

The experimental results from Figs. 4 and 5 are compiled in this table. EC₅₀ values were derived from the equation: Y = 100/(1 + 10((log EC₅₀ − X)·HS), where Y is the percentage of the maximal effect at a given concentration (X), and HS is the Hill slope (Hill slope = 1). K_i values were derived from the one site − fit K_i equation in Prism 5 using a published K_d of 0.015 nm (17).

nAChR subtype	Functional potency		Ligand binding affinity
	EC50	na	Ki	n
	nm		nm
α4β2	25.2 ± 6.1c	4	0.87 ± 0.16	6
α4ΔCβ2	16.2 ± 4.2	4	0.72 ± 0.11	5
α4ΔΔCβ2	23.7 ± 5.1	3	0.96 ± 0.16	3
α4C273Sβ2	20.2 ± 4.4	3	1.0 ± 0.16	3

^a n = the number of independent experiments that were performed for each construct.

^b Data are expressed as means ± S.E. There are no significant differences between the groups for EC₅₀ or K_i, as determined by one-way ANOVA.