Table 2.
Receptor | [3H]-NMS binding |
Carbachol binding, Ki (μM) | |
---|---|---|---|
KD pM | Bmax (pmol/mg protein) | ||
M3′(3C)-Xa | 524 ± 98 | 5.82 ± 1.39 | 45.7 ± 8.9 |
K259C | 877 ± 365 | 5.00 ± 2.41 | 32.7 ± 4.1 |
R260C | 733 ± 137 | 3.99 ± 1.71 | 46.1 ± 0.8 |
E263C | 421 ± 210 | 4.42 ± 0.08 | 26.0 ± 9.6 |
L264C | 719 ± 96 | 4.85 ± 0.45 | 26.2 ± 9.7 |
Membranes prepared from COS-7 cells expressing the indicated M3′(3C)-Xa-derived Cys-substituted mutant M3R (rat) constructs were incubated with 100 μM Cu-Phen (10 min at 22°C), and radioligand binding assays were performed and analyzed as described in Materials and Methods. Data are shown as means ± se of 2 or 3 independent experiments.