<br/>The δ-opioid receptor (DOR) is a critical pharmaceutical target for pain management. Although the high-resolution crystal structures of the DOR with both agonist and antagonist have recently been solved, the activation mechanism remains to be elusive. In this study, a DOR agonist ADL5859 was docked to the inactive DOR and multiple microsecond molecular dynamic (MD) simulations were conducted to probe the activation mechanism. While the receptor with the crystal ligand (i.e. antagonist naltrindole) maintained the inactive conformation in all three independent simulations, the receptor with ADL5859 was adopting toward the active conformation in three out of six independent simulations. Major conformational differences were located on transmembrane 5 and 6, as well as intracellular loop 3. Compared to naltrindole, ADL5859 exhibited high conformational flexibility and strong interaction with the transmission switch. The putative key residues involving in the activation were identified through the conventional molecular switch analysis and a pairwise distance analysis. These insights will facilitate further development of therapeutic agents targeting the DOR.

To probe the activation mechanism of the delta opioid receptor by an agonist ADL5859 started from an inactive conformation using molecular dynamic simulations

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.