Translocation Mechanism of Allosteric Sodium Ions in β2-Adrenoceptor

J Chem Inf Model. 2022 Jun 27;62(12):3090-3095. doi: 10.1021/acs.jcim.2c00170. Epub 2022 Jun 13.

Abstract

The allosteric modulation of G-protein-coupled receptors (GPCRs) by sodium ions has received significant attention as the crystal structures of several receptors show the binding of sodium ions (Na+) at the conserved D2.50. Theoretical studies have shown that extracellular Na+ would enter the allosteric D2.50 via the orthosteric site. However, it remains unclear how the bound allosteric Na+ would leave the GPCRs. In this study, we performed molecular dynamics (MD) simulations to illustrate the energy barriers of Na+ transfer through the transmembrane helix bundle of β2AR. In contrast to the postulations from other GPCRs, the translocation of this allosteric Na+ into the intracellular side is found to be significantly difficult. Hence, the translocation direction could be receptor-specific.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Allosteric Regulation
  • Allosteric Site
  • Ions
  • Molecular Dynamics Simulation*
  • Receptors, G-Protein-Coupled / chemistry
  • Sodium* / chemistry

Substances

  • Ions
  • Receptors, G-Protein-Coupled
  • Sodium