Table 1. Pharmacological Properties of Various (α6β2)₂β3 AChR Constructs.

	AChR Construct
Agonist	1	4	5	6	7	8	9
	β3−α6−β2−α6−β2	α6α3cyt+β2+β3	α6211L,α3cyt+β2+β3	α6α3cyt-C+β2+β3	β3–α6+α6α3cyt+β2	β3–α6+α6211L,α3cyt+β2	β3–α6211L,α3cyt+α6211L,α3cyt+β2
ACh
EC50 (µM)	1.21±0.16	0.740±0.096	0.33±0.25	0.756±0.262	1.40±0.348	0.669±0.067	6.06±2.68
Nicotine
EC50 (µM) Efficacy (%)	0.239±0.031 34.5±2.4	0.116±0.044 37.8±4.9	0.203±0.054 30.7±26.7	0.711±0.120 27.5±1.6	0.155±0.081 26.2±5.0	0.135±0.083 30.5±5.4	0.145±0.055 33.3±3.5
Cytisine
EC50 (µM) Efficacy (%)	0.189±0.052 17.0±1.0	0.219±0.152 14.9±2.9	0.256±0.020 10.4±0.2	0.336±0.047 32.3±1.3	0.160±0.102 12.5±2.1	0.198±0.139 9.92±2.10	0.221±0.146 9.46±1.99
Varenicline
EC50 (µM) Efficacy (%)	0.0620±0.0248 16.1±1.5	0.138±0.071 9.37±1.18	0.104±0.012 18.3±0.7	0.0374±0.0137 27.6±3.0	0.138±0.166 15.6±4.9	0.0978±0.0951 22.9±6.1	0.114±0.036 5.59±0.06

Note the EC₅₀ values for construct 6, which contains the α3 cytoplasmic domain, transmembrane domain 4, and the extracellular C-terminal domain, are significantly different from those of construct 1 for nicotine (p = 0.0266).