Table 1.

Agonist and modulator activation involve the β2 C loop

Subtype	ACh Activation		ACh + Mor Modulation			ACh + Oxa Modulation
	EC₅₀ (µM)	n_H	EC₅₀ (µM)	n_H	E_max	EC₅₀ (µM)	n_H	E_max
α3β2^a	66 ± 9	0.75 ± 0.07	10 ± 2	1.37 ± 0.80	2.64 ± 0.29	9 ± 1	1.54 ± 0.25	2.27 ± 0.06
α3Y168C· β2D190C	37 ± 6	0.68 ± 0.08 [10]	2.9 ± 0.6	1.22 ± 0.33 [4–5]	1.37 ± 0.06	9.5 ± 4.0	1.13 ± 0.45 [5]	1.38 ± 0.11
α3Y168Cβ2	36 ± 8	0.70 ± 0.11 [11]	1.6 ± 0.6	1.17 ± 0.47 [6]	1.46 ± 0.08	5.9 ± 1.6	1.01 ± 0.27 [6]	1.34 ± 0.06
α3β2D190C	12 ± 2	1.05 ± 0.14 [9]	19 ± 8	1.08 ± 0.42 [4]	0.95 ± 0.08	31 ± 12	1.13 ± 0.44 [5]	0.83 ± 0.08
α3Y168Fβ2	14 ± 2	0.61 ± 0.04 [12]	0.14 ± 0.03	0.50 ± 0.08 [6]	1.15 ± 0.03	2.9 ± 0.2	1.73 ± 0.66 [6]	1.16 ± 0.02
α3β2D190Q	12 ± 2	1.00 ± 0.15 [8]	13 ± 6	0.73 ± 0.25 [4]	1.20 ± 0.11	31 ± 5	1.19 ± 0.21 [4]	0.97 ± 0.04
α3Y168F β2D190Q	46 ± 7	0.83 ± 0.09 [11]	4.0 ± 1.2	1.17 ± 0.33 [4]	2.57 ± 0.14	10 ± 1	1.10 ± 0.09 [4]	1.06 ± 0.02

Fits to the Hill equation for experiments with ACh alone, ACh +10 µM Mor or ACh +10 µM Oxa. In all experiments for the α3Y168Cβ2D190C double mutant, recordings were made on naive oocytes, having had no previous oxidation or reduction treatment [n] indicates the number of replicate oocytes for each measurement.

Data for wild type α3β2 from 32.