Combination | Fractional potentiation | EC50 | Hill coefficient | n |
---|---|---|---|---|
nm | ||||
Wild-type | ||||
α1β2γ2 | 2.57 ± 0.020 | 64.8 ± 3.7 | 1.16 ± 0.04 | 24 |
β2γ2 | 2.60 ± 0.02 | 38.3 ± 12.4 | 1.32 ± 0.08 | 2 |
α1 Mutants | ||||
F65Y | 1.98 ± 0.08 | 67.9 ± 0.8 | 1.22 ± 0.12 | 2 |
H100R1-a | Potentiation nearly abolished | 4 | ||
Y159F | 2.28 ± 0.03 | 118.2 ± 39.4 | 1.09 ± 0.06 | 3 |
Y159S1-a | Potentiation nearly abolished | 3 | ||
Y161S | 2.02 ± 0.18 | 58.6 ± 6.2 | 1.11 ± 0.07 | 6 |
T162A | 3.17 ± 0.66 | 131.1 ± 37.8 | 1.29 ± 0.31 | 3 |
Y169S | 1.55 ± 0.24 | 43.1 ± 7.0 | 1.18 ± 0.11 | 5 |
Y209F | 2.26 ± 0.24 | 140.9 ± 3.2 | 1.31 ± 0.02 | 4 |
Y209S | 1.54 ± 0.11 | 463.2 ± 51.2 | 1.03 ± 0.08 | 11 |
γ2 Mutants | ||||
Y172S | 1.98 ± 0.10 | 118.5 ± 12.0 | 1.44 ± 0.06 | 3 |
Y220S | 2.51 ± 0.36 | 129.7 ± 5.3 | 1.59 ± 0.30 | 2 |
Parameters were determined by fitting the Hill equation to the dose-response relationship for dzp at ≤1 μm except for the α1Y209S mutant, which was fit to ≤10 μm dzp. In all cases, the fractional potentiation was examined in the presence of 3 μm GABA. Values are mean ± standard error.
↵1-a For these mutants, the potentiation was nearly abolished, preventing the fitting of the Hill equation to the dose-response relationships.