Synopsis of the descriptors of the allosteric interaction between W84 and the indicated ligands at guinea pig cardiac M2 receptors, as derived from experiments in isolated atria and from radioligand binding experiments in cardiac membranes
| Modulator | Oxo | AF-DX 384 | NMS |
|---|---|---|---|
| W84 | |||
| Atria | |||
| K A (nm) | 137 | ||
| α | 311 | 444 | 18 |
| α·K A(nm) | 42,607 | 60,828 | 2,466 |
| Membranes | |||
| ECdiss (nm) | 33,300 | 900 | |
| K A (nm) | 215 | 457 | |
| α | 194 | 2.4 | |
| α·K A(nm) | 41,700 | 1,097 |
K A is the equilibrium dissociation constant for the binding of W84 to the unoccupied receptor, α is the cooperativity factor for the interaction of W84 with oxotremorine (Oxo), AF-DX 384, and NMS, respectively α · K A represents the equilibrium dissociation constant for the binding of W84 to the complex formed by the indicated ligand and the receptor, and ECdiss is concentration of W84 inducing a half-maximum retardation of [3H]ligand dissociation.