Probe Confined Dynamic Mapping for G Protein-Coupled Receptor Allosteric Site Prediction

Targeting G protein-coupled receptors (GPCRs) through allosteric sites offers advantages over orthosteric sites in identifying drugs with increased selectivity and potentially reduced side effects. In this study, we developed a probe confined dynamic mapping protocol that allows the prediction of allosteric sites at both the GPCR extracellular and intracellular sides, as well as at the receptor-lipid interface. The applied harmonic wall potential enhanced sampling of probe molecules in a selected area of a GPCR while preventing membrane distortion in molecular dynamics simulations. The specific probes derived from GPCR allosteric ligand structures performed better in allosteric site mapping compared to commonly used cosolvents. The M-2 muscarinic, beta(2) adrenergic, and P2Y1 purinergic receptors were selected for the protocol's retrospective validation. The protocol was next validated prospectively to locate the binding site of [5-fluoro-4-(hydroxymethyl)-2-methoxyphenyl]-(4-fluoro-1H-indol-1-yl)methanone at the D-2 dopamine receptor, and subsequent mutagenesis confirmed the prediction. The protocol provides fast and efficient prediction of key amino acid residues surrounding allosteric sites in membrane proteins and facilitates the structure-based design of allosteric modulators.

Automated summary

This study developed a probe confined dynamic mapping protocol to predict allosteric sites on GPCRs, demonstrating the advantage of specific probes derived from GPCR allosteric ligand structures over commonly used cosolvents in allosteric site mapping. The protocol was successfully validated retrospectively on selected receptors and prospectively on the D-2 dopamine receptor, confirming the prediction through subsequent mutagenesis. It provides a fast and efficient prediction of key amino acid residues surrounding allosteric sites in membrane proteins, aiding in the design of allosteric modulators based on protein structure.