The role of water and sodium ions in the activation of the μ-opioid receptor

Abstract

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.

Keywords: G-protein-coupled receptors; activation mechanisms; activation switches; opioid receptor; sodium ions.