Table 2.

Surface expression of all concatamers alone and with free α4 or β2 subunits

AChR	Surface AChR (fmol ¹²⁵I-mAb 295 binding site/oocyte)	Total current^a (μA)	Specific activity (current/surface AChR) (μA/fmol mAb 295 binding)	Relative specific activity^b to wild-type α4β2(1:1)
α4β2(1:1)	11.4±1.23	2.42±0.15	0.21	1.0
α-12-β	0.94±0.11	1.39±0.07	1.47	6.9
α-12-β + α4	2.79±0.27	6.42±0.34	2.31	10.9
α-12-β + β2	2.74±0.23	0.11±0.01	0.04	0.2
β-6-α	1.01±0.15	1.75±0.09	1.72	8.1
β-6-α + α4	3.09±0.27	7.29±0.44	2.36	11.1
β-6-α + β2	5.20±0.63	1.30±0.08	0.25	1.2
α-6-β	2.05±0.79	0.13±0.02	0.06	0.3
α-6-β + α4	2.70±0.74	1.38±0.31	0.51	2.4
α-6-β + β2	4.19±1.90	0.17±0.05	0.04	0.2
β-α	0.06±0.01	0.02±0.00	0.27	1.3
β-α + α4	0.49±0.07	0.36±0.05	0.73	3.5
β-α + β2	0.60±0.09	0.16±0.02	0.26	1.2

↵ a Measured at 100 μm ACh.
↵ b All numbers in the specific activity column were divided by 0.21 [specific activity of α4β2(1:1)].