TABLE 3

Functional effects of ACh, DHβE, and erysodine on wild-type and N-terminal domain mutant α4β2 nAChRs

Data represent the mean ± S.E.M. of n number of experiments. Wild-type and mutant α4β2 nAChRs were expressed heterologously in X. laevis oocytes as described under Materials and Methods.

	ACh		IC₅₀		n
	I/Wild-type I_max	EC₅₀	DHβE	Erysodine	n
		μM	μM	μM
α4β2	1	92 ± 21	0.11 ± 0.009	0.096 ± 0.005	10
α4Y126Aβ2	0.22 ± 0.1^**	530 ± 100^*	20 ± 12^**	19 ± 8^**	3
α4W182Aβ2	0.87 ± 0.06	451 ± 54^**	5.5 ± 0.5^***	4.43 ± 0.11^**	7
α4Y223Aβ2	N.A.	N.A.	N.A.	N.A.	4
α4Y230Aβ2	0.25 ± 0.08^**	401 ± 45^**	3.2 ± 0.4^***	3.17 ± 0.9^***	6
α4β2D196A	0.98 ± 0.1	114 ± 45	N.E.	N.E.	10
α4β2W82A	0.42 ± 0.09^*	313 ± 61^*	1.41 ± 0.8^**	2 ± 0.8^**	6
α4β2T84A	0.51 ± 0.09^*	201 ± 28^*	0.87 ± 0.1^***	1.2 ± 0.4^***	6

N.A., not available (current responses were below the limits of detection); N.E., no functional effects at the highest concentration of inhibitor tested, 1 mM.
↵* , P ≤ 0.05;
↵** , P < 0.01;
↵*** , P < 0.001, relative to effects on wild-type α4β2 receptors.