Protease-activated receptor 2 (PAR2) is a G-protein-coupled receptor that is activated by proteolytic cleavage of its N-terminus. The unmasked N-terminal peptide then binds to the transmembrane bundle, leading to activation of intracellular signaling pathways associated with inflammation and cancer. Recently determined crystal structures have revealed binding sites of PAR2 antagonists, but the binding mode of the peptide agonist remains unknown. In order to generate a model of PAR2 in complex with peptide SLIGKV, corresponding to the trypsin-exposed tethered ligand, the orthosteric binding site was probed by iterative combinations of receptor mutagenesis, agonist ligand modifications, and data-driven structural modeling. Flexible-receptor docking identified a conserved binding mode for agonists related to the endogenous ligand that was consistent with the experimental data and allowed synthesis of a novel peptide (1-benzyl-1H[1,2,3]triazole-4-yl-LIGKV) with functional potency higher than that of SLIGKV. The final model may be used to understand the structural basis of PAR2 activation and in virtual screens to identify novel agonists and competitive antagonists. The combined experimental and computational approach to characterize agonist binding to PAR2 can be extended to study the many other G protein-coupled receptors that recognize peptides or proteins.
Structural Characterization of Agonist Binding to Protease- Activated Receptor 2 through Mutagenesis and Computational Modeling
Posted by
Jens Carlsson
on 12 09 2019
Related content
19 04 2023
< 1 minute
Predicting pKa
One of the most important physicochemical properties of small molecules and macromolecules are the...
12 05 2022
< 1 minute
Coupling stabilizers open KV1-type potassium channels
ABSTRACT: The opening and closing of voltage-gated ion channels are regulated by voltage sensors...
12 11 2021
< 1 minute
Responding to the Challenge Posed by the Generic Control of Substances
Drug monitoring organizations report that new psychoactive substances continue to emerge, posing...
12 10 2021
< 1 minute
Boost analytical experiments with phys-chem properties
Physicochemical properties have a fundamental impact on analytical experiment conditions,...