Table 1.

Summary of GABA dose–response data from cysteine-substituted and wild-type α1β2GABAA receptors

EC50m)Mutant/WT
αβ8.2  ± 0.41.00
αT60Cβ7.5  ± 0.60.92
αI61Cβ3.4  ± 0.30.41
αD62Cβ28  ± 23.46
αV63Cβ3.0  ± 0.20.37
αF64Cβ594  ± 1172.8
αF65Cβ19  ± 22.34
αR66Cβ2610  ± 160320
αQ67Cβn.d.
αS68Cβ8.0  ± 0.70.97
αW69Cβn.d.
αK70Cβ4.6  ± 0.30.56
  • Oocytes were treated with increasing concentrations of GABA, and current responses were recorded by two-electrode voltage clamp. Data were fit by nonlinear regression analysis as described in Materials and Methods. Mutant/WT, the ratio of the EC50 for GABA of cysteine mutant receptors to the EC50 for GABA of wild-type α1β2 GABAA receptors; n.d., no detectable current.