Table 2.
EC50 values and Hill coefficients of GABA-induced currents and fluorescence changes in six fluorescently labelled cysteine mutants of the ρ1 GABA receptor expressed in Xenopus oocytes
| Current | Fluorescence change | |||||
|---|---|---|---|---|---|---|
| Construct | EC50(μm) | nH | n | EC50(μm) | nH | n |
| WT | 0.81 ± 0.04‡ | 2.83 ± 0.07‡ | ND | ND | ||
| K210C | 1.95 ± 0.17 | 2.42 ± 0.03 | 3 | 1.89 ± 0.04 | 1.86 ± 0.04* | 3 |
| K211C | 0.47 ± 0.02 | 2.84 ± 0.04 | 4 | ND | ND | |
| L216C | 6.50 ± 0.32 | 2.78 ± 0.06 | 4 | 7.66 ± 0.35 | 1.50 ± 0.36* | 4 |
| K217C | 2.16 ± 0.09 | 2.37 ± 0.03 | 4 | 2.51 ± 0.03* | 1.63 ± 0.12** | 4 |
| T218C | 2.17 ± 0.24 | 2.48 ± 0.09 | 4 | 3.18 ± 0.09* | 1.97 ± 0.10* | 3 |
| I222C | 2.74 ± 0.09 | 1.91 ± 0.04 | 7 | 3.14 ± 0.10* | 2.12 ± 0.23 | 6 |
WT: wild-type ρ1 GABA receptor; ND: not determined; nH: Hill coefficient.
‡
Value from a previous publication (Chang & Weiss, 1999b).
*
P < 0.05 when compared to parameters for current;
**
P < 0.01 when compared to parameters for current.