Estimated parameters of the ACh CRCs from α2β4 nAChRs, formed by wild-type or cysteine mutants of the α2 subunit
The mutants α2(S256C)β4, α2(F260C)β4, α2(I264C)β4, and α2(E266C)β4 (10′, 14′, 18′, and 20′, respectively) gave little or no ACh-induced currents. Values are mean of N oocytes, values between brackets indicate 95% confidence intervals.
Receptor | General Notation | N | EC50 (μM ACh) | nH | Imax Range |
|---|---|---|---|---|---|
| nA | |||||
| α2β4 wild-type | 18 | 55.1 [49.1-61.9] | 1.32 [1.16-1.48] | 662-13,000 | |
| α2(L257C)β4 | 11′ | 7 | 52.5 [46.4-59.3] | 1.68 [1.41-1.95] | 1,350-10,000 |
| α2(T258C)β4 | 12′ | 5 | 65.0 [46.3-91.2] | 1.31 [0.86-1.75] | 425-3,850 |
| α2(V259C)β4 | 13′ | 6 | 3.2 [2.66-3.80] | 1.45 [1.13-1.78] | 325-3,000 |
| α2(L261C)β4a | 15′ | 6 | 77 [49.8-119.6] | 0.99 [0.70-1.28] | 155-1,050 |
| α2(L262C)β4 | 16′ | 9 | 4.2 [2.8-6.2] | 0.96 [0.68-1.24] | 388-11,250 |
| α2(L263C)β4 | 17′ | 6 | 17.0 [13.7-21.3] | 1.75 [1.19-2.31] | 165-2,925 |
| α2(T265C)β4 | 19′ | 6 | 89.6 [73.0-110.0] | 1.31 [1.03-1.60] | 130-2,100 |
↵ a Data from Borghese et al., 2002.