Characteristics of the potentiation of [3H]ryanodine binding by flubendiamide
The effects of the compound on the binding of 5 nM [3H]ryanodine were determined in the solutions with endogenous modulators for RyR. Binding solution contained 1 M KCl, 0.3 M sucrose, and 10 mM Tris/HCl, pH 7.4. Ca2+-ATPase assay solution contained 100 mM KCl, 6 mM MgCl2, 0.05 mM CaCl2, 1 mM ATP, and 50 mM Tris/MOPS, pH 7.4.
| Solution | Ca2+ | Additives | EC50 | Bmax |
|---|---|---|---|---|
| mM | nM | pmol/mg protein | ||
| Binding | 1 | 0.12 | 0.35 | |
| Binding | 1 | ATP (1 mM) | 0.14 | 0.41 |
| Binding | 1 | Mg2+ (6 mM) | 0.12 | 0.39 |
| Binding | EGTA (1 mM) | 26 | 0.30 | |
| Ca2+-ATPase assay | 0.05 | ATP (1 mM), Mg2+ (6 mM) | 2.5 | 0.14 |