Development of a 3D model for the human cannabinoid CB1 receptor.

A novel comparison model of the human cannabinoid CB1 receptor has been constructed using the bovine rhodopsin X-ray structure as a template. The model was subjected to a 500-ps molecular dynamics simulation, and thereafter new conformers of the receptor model were produced in a simulated annealing procedure. Using an automated docking procedure, well-known cannabimimetic ligands were docked into six different model conformers, of which one was chosen for a detailed study of receptor-ligand interactions. The docking results confirm, for example, the importance of lysine K3.28(192) in the binding of these ligands. Also, other experimental data are fairly consistent with the present model, though there are some differences when compared to other recent CB1 comparison models. The present model will serve as a tool to investigate the receptor-ligand interactions and facilitate the design of novel cannabimimetic drugs.