Molecular determinants of biased agonism at the dopamine D₂ receptor

J Med Chem. 2015 Mar 26;58(6):2703-17. doi: 10.1021/jm501889t. Epub 2015 Mar 12.

Abstract

The development of biased (functionally selective) ligands provides a formidable challenge in medicinal chemistry. In an effort to learn to design functionally selective molecular tools for the highly therapeutically relevant dopamine D2 receptor, we synthesized a collection of agonists based on structurally distinct head groups derived from canonical or atypical dopaminergic pharmacophores. The test compounds feature a long lipophilic appendage that was shown to mediate biased signaling. By employing functional assays and molecular dynamics simulations, we could show that atypical dopamine surrogates of type 1 and 2 promote biased signaling, while ligands built from classical dopaminergic head groups (type 3 and 4) typically elicit more balanced signaling profiles. Besides this, we found a strong influence of the stereochemistry of type 4 aminotetraline-derived agonists on functional selectivity at D2 receptors. Whereas the (S)-enantiomer behaved as a full agonist, the biased ligand (R)-4 induced poor G protein coupling but substantial β-arrestin recruitment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arrestins / metabolism
  • Dopamine / analogs & derivatives*
  • Dopamine / pharmacology*
  • GTP-Binding Proteins / metabolism
  • HEK293 Cells
  • Humans
  • Ligands
  • Models, Molecular
  • Receptors, Dopamine D2 / agonists*
  • Receptors, Dopamine D2 / metabolism
  • Signal Transduction / drug effects
  • beta-Arrestins

Substances

  • Arrestins
  • Ligands
  • Receptors, Dopamine D2
  • beta-Arrestins
  • GTP-Binding Proteins
  • Dopamine