Muscimol binding and receptor expression at the cell surface
| Receptor | Kd | Bmax | EPM | ETC |
|---|---|---|---|---|
| nM | % | |||
| αβ (WT) | 39 ± 5 (16) | 5.8 ± 0.2 (16) | 100 | 100 |
| α(L9′F)β | 52 ± 9 (6) | 6.9 ± 0.3 (6)3-a | 109 ± 9 (5) | 98 ± 6 (5) |
| αβ(L9′F) | 92 ± 13 (8)3-a | 6.2 ± 0.3 (8) | 84 ± 5 (5) | 101 ± 15 (5) |
| α(L9′F)β(L9′F) | 55 ± 6 (8)3-a | 2.7 ± 0.3 (8)3-a | 51 ± 5 (10) | 75 ± 6 (10) |
| α(L9′Y)β | 32 ± 5 (6) | 4.8 ± 0.2 (6)3-a | 106 ± 17 (5) | 110 ± 8 (5) |
| αβ(L9′Y) | 49 ± 7 (6) | 4.6 ± 0.2 (6)3-a | 83 ± 8 (5) | 105 ± 12 (5) |
| α(L9′Y)β(L9′Y) | 88 ± 14 (6)3-a | 3.4 ± 0.2 (6)3-a | 60 ± 2 (5) | 82 ± 7 (5) |
| αβ(L9′A) | 77, 96 | 5.6, 6.0 | ||
| α(L9′A)β(L9′A) | 13, 23 | 6.0, 6.4 | ||
Muscimol binding parameters were calculated using eq. 2 for a single class of binding sites. Kd is the muscimol dissociation constant, and Bmax is maximal binding (pmol/106 cells). Values represent the mean ± S.E. forn ≥ 3. For detection of α1 in the plasma membrane and within the cell, Sf9 cells were labeled with the α1-specific monoclonal antibody, bd24, and the fluorescence of a FITC-conjugated secondary antibody was detected by flow cytometry. The level of plasma membrane (EPM) and the total cell (ETC) immunofluorescence is expressed as a percent of wild-type (αβ) immunofluorescence. The number of experiments carried out is shown in parentheses.
↵3-a Values that are significantly different from wild type (WT), P ≤ .05.