The Role of Water and Sodium Ions in the Activation of the μ‐Opioid Receptor

Dual effect of sodium ions : The activation of G‐protein‐coupled receptors depends on the presence of water molecules inside the receptor and also on allosteric interactions. The binding of sodium ions to the allosteric site of the μ opioid receptor was studied by microsecond molecular dynamics simulations and their seemingly contradictory roles in preventing ligand binding and facilitating receptor activation were explained.