Binding Site of Loperamide: Automated Docking of Loperamide in Human mu- and delta-Opioid Receptors

Loperamide is a piperidine analogue, acting as agonist on peripheral opioid receptors, exhibiting affinity and selectivity for the cloned μ human opioid receptor compared with the δ human opioid receptor. Automatic docking studies of loperamide, using AutoDock, on human μ- and δ-opioid receptors is described. Whilst no meaningful difference was detected concerning the docking of the arylpiperidine moiety, μ/δ selectivity could be explained as a different accommodation of the two phenyl groups in two lipophylic pockets of receptors