| Autor: |
Casajuana-Martin, Nil, Navarro, Gemma, Gonzalez, Angel, Llinas del Torrent, Claudia, Gómez-Autet, Marc, Quintana García, Aleix, Franco, Rafael, Pardo, Leonardo |
| Zdroj: |
Journal of Chemical Information and Modeling; 20220101, Issue: Preprints |
| Abstrakt: |
Molecular dynamic (MD) simulations have become a common tool to study the pathway of ligand entry to the orthosteric binding site of G protein-coupled receptors. Here, we have combined MD simulations and site-directed mutagenesis to study the binding process of the potent JWH-133 agonist to the cannabinoid CB2receptor (CB2R). In CB2R, the N-terminus and extracellular loop 2 fold over the ligand binding pocket, blocking access to the binding cavity from the extracellular environment. We, thus, hypothesized that the binding pathway is a multistage process consisting of the hydrophobic ligand diffusing in the lipid bilayer to contact a lipid-facing vestibule, from which the ligand enters an allosteric site inside the transmembrane bundle through a tunnel formed between TMs 1 and 7 and finally moving from the allosteric to the orthosteric binding cavity. This pathway was experimentally validated by the Ala2827.36Phe mutation that blocks the entrance of the ligand, as JWH-133 was not able to decrease the forskolin-induced cAMP levels in cells expressing the mutant receptor. This proposed ligand entry pathway defines transient binding sites that are potential cavities for the design of synthetic modulators. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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