Table 1.
Binding of BM and BMSA to SUR2B in membranes and intact cells
| Preparation | Incubation time (min) | Ki (BM) (nM) | Ki (BMSA) (μM) | Ki (BMSA)/Ki (BM)a |
|---|---|---|---|---|
| Kir6.2/SUR2B (membranes) | 30 | 61 (51, 74) | 4.3 (4.1, 4.5) | 69 (58, 83) |
| Kir6.2/SUR2B (cells) | 30 | 35 (34, 37) | 186 (162, 214) | 5200 (4600, 6000) |
| 120 | 52 (45, 62)* | 85 (59, 123)* | 1600 (1100, 2400)* | |
| SUR2B alone (cells) | 30 | 44 (42, 46) | 169 (147, 193) | 3900 (3400, 4500) |
Abbreviations: BM, bimakalim; BMSA, descyano-bimakalim-6-sulphonic acid; Kir, inwardly rectifying K+ channel; SUR, sulphonylurea receptor.
Binding inhibition curves are shown in Figure 3.
Ki values are followed by the 95% confidence interval.
*
Significantly different from the respective value at 30 min (P<0.05, t-test performed at the level of the pKi values).
a
Ratio calculated from the difference of the pKi values taking propagation of errors into account.