Effect of alanine substitution within the intracellular loop of rat μ-opioid receptor on 3H-diprenorphine binding parameters.
| [3H]Diprenorphine saturation binding assays were carried out using membranes prepared from HEK293 cells stably expressing wild-type or mutant receptors. The saturation binding experiments were performed as described under Materials and Methods. Curve fitting for the binding data was performed using the GraphPad Prism program. Data represents mean ± S.E.M. of two to three separate experiments in duplicate or triplicate. | ||||
|---|---|---|---|---|
| Receptor | [3H]Diprenorphine | |||
| KD1 | Bmax | |||
| nM | pmol/mg | |||
| WT | 0.33 ± 0.01 | 9.4 ± 0.77 | ||
| R276A | 0.48 ± 0.07 | 3.0 ± 0.19 | ||
| R277A | 0.41 ± 0.04 | 8.9 ± 1.3 | ||
| I278A | 0.45 ± 0.19 | 4.5 ± 0.02 | ||
| T279A | 0.41 ± 0.02 | 2.0 ± 0.16 | ||
| R280A | 0.46 ± 0.08 | 2.8 ± 0.42 | ||
| R276A/R277A | 0.37 ± 0.11 | 11 ± 2.6 | ||
WT, wild-type.