Binding affinities of BZD site ligands for myc-tagged γ2, γ2 A79 mutants, and γ2 T81 mutants
| Receptor | Flunitrazepam | Ro15-4513 | Ro15-1788 | ||||||
|---|---|---|---|---|---|---|---|---|---|
| KI | n | KI-mut/KI-αβγ | KI | n | KI-mut/KI-αβγ | KI | n | KI-mut/KI-αβγ | |
| nM | nM | nM | |||||||
| αβγmyc | 8.9 ± 0.9 | 3 | 1.0 | 3.9 ± 0.9 | 6 | 1.0 | 3.5 ± 0.2 | 3 | 1.0 |
| αβγA79R | 24.3 ± 5.42-150 | 3 | 2.7 | 5.6 ± 1.6 | 3 | 1.4 | 5.6 ± 0.8 | 3 | 1.6 |
| αβγA79C | 47.6 ± 5.32-150 | 3 | 5.3 | 62.1 ± 15.42-150 | 3 | 15.9 | 20.3 ± 1.12-150 | 3 | 5.8 |
| αβγA79Y | 6.1 ± 2.2 | 3 | 0.7 | 201.5 ± 25.72-150 | 3 | 51.7 | 74.1 ± 10.62-150 | 3 | 21.2 |
| αβγA79Q | 79.5 ± 12.62-150 | 3 | 8.9 | 112.2 ± 31.72-150 | 3 | 28.8 | 64.7 ± 12.52-150 | 3 | 18.5 |
| αβγT81S | 14.2 ± 2.7 | 3 | 1.6 | 4.2 ± 2.0 | 6 | 1.1 | 6.8 ± 1.02-150 | 4 | 1.9 |
| αβγT81A | 8.2 ± 0.9 | 3 | 0.9 | 17.0 ± 4.92-150 | 4 | 4.4 | 4.1 ± 0.3 | 3 | 1.2 |
| αβγT81C | 32.8 ± 7.62-150 | 3 | 3.7 | 16.9 ± 7.12-150 | 4 | 4.3 | 8.7 ± 1.72-150 | 3 | 2.5 |
Ro15-4513 KI values for αβγmyc and αβγT81 mutant receptors were determined by homologous competition radioligand binding assays. All other KI values were determined by displacement of [3H]flunitrazepam binding. Results shown are the mean ± S.E.; n is the number of independent experiments. Statistical differences between logKI values were determined by one-way ANOVA using Dunnett's post-test.
↵2-150 Significantly different from αβγmyc(P < .01).