Mass spectrometry captures biased signalling and allosteric modulation of a G-protein-coupled receptor

Nat Chem. 2022 Dec;14(12):1375-1382. doi: 10.1038/s41557-022-01041-9. Epub 2022 Nov 10.


G-protein-coupled receptors signal through cognate G proteins. Despite the widespread importance of these receptors, their regulatory mechanisms for G-protein selectivity are not fully understood. Here we present a native mass spectrometry-based approach to interrogate both biased signalling and allosteric modulation of the β1-adrenergic receptor in response to various ligands. By simultaneously capturing the effects of ligand binding and receptor coupling to different G proteins, we probed the relative importance of specific interactions with the receptor through systematic changes in 14 ligands, including isoprenaline derivatives, full and partial agonists, and antagonists. We observed enhanced dynamics of the intracellular loop 3 in the presence of isoprenaline, which is capable of acting as a biased agonist. We also show here that endogenous zinc ions augment the binding in receptor-Gs complexes and propose a zinc ion-binding hotspot at the TM5/TM6 intracellular interface of the receptor-Gs complex. Further interrogation led us to propose a mechanism in which zinc ions facilitate a structural transition of the intermediate complex towards the stable state.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Allosteric Regulation
  • GTP-Binding Proteins / metabolism
  • Ions
  • Isoproterenol / pharmacology
  • Ligands
  • Mass Spectrometry
  • Receptors, Adrenergic, beta-2* / chemistry
  • Receptors, Adrenergic, beta-2* / metabolism
  • Receptors, G-Protein-Coupled* / metabolism
  • Zinc / metabolism


  • Receptors, Adrenergic, beta-2
  • Isoproterenol
  • Receptors, G-Protein-Coupled
  • Ligands
  • GTP-Binding Proteins
  • Ions
  • Zinc

Associated data

  • figshare/10.6084/m9.figshare.19688640
  • figshare/10.6084/m9.figshare.19754662.v1