PMID- 32701545 OWN - NLM STAT- MEDLINE DCOM- 20201116 LR - 20221005 IS - 1526-7598 (Electronic) IS - 0003-2999 (Print) IS - 0003-2999 (Linking) VI - 131 IP - 3 DP - 2020 Sep TI - Molecular Interaction Between Butorphanol and kappa-Opioid Receptor. PG - 935-942 LID - 10.1213/ANE.0000000000005017 [doi] AB - BACKGROUND: The misuse of opioids stems, in part, from inadequate knowledge of molecular interactions between opioids and opioid receptors. It is still unclear why some opioids are far more addictive than others. The kappa-opioid receptor (KOR) plays a critical role in modulating pain, addiction, and many other physiological and pathological processes. Butorphanol, an opioid analgesic, is a less addictive opioid with unique pharmacological profiles. In this study, we investigated the interaction between butorphanol and KOR to obtain insights into the safe usage of this medication. METHODS: We determined the binding affinity of butorphanol to KOR with a naltrexone competition study. Recombinant KORs expressed in mammalian cell membranes (Chem-1) were used for G-protein activation studies, and a human embryonic kidney-293 (HEK-293) cell line stably transfected with the human KOR was used for beta-arrestin study as previously described in the literature. The effects of butorphanol on KOR internalization were investigated using mouse neuroblastoma Neuro2A cells stably transfected with mKOR-tdTomato fusion protein (N2A-mKOR-tdT) cells overexpressing KOR. The active-state KOR crystal structure was used for docking calculation of butorphanol to characterize the ligand binding site. Salvinorin A, a full KOR agonist, was used as a control for comparison. RESULTS: The affinity of KOR for butorphanol is characterized by Kd of 0.1 +/- 0.02 nM, about 20-fold higher compared with that of the micro-opioid receptor (MOR; 2.4 +/- 1.2 nM). Our data indicate that butorphanol is more potent on KOR than on MOR. In addition, butorphanol acts as a partial agonist of KOR in the G-protein activation pathway and is a full agonist on the beta-arrestin recruitment pathway, similar to that of salvinorin A. The activation of the beta-arrestin pathway is further confirmed by KOR internalization. The in silico docking model indicates that both salvinorin A and butorphanol share the same binding cavity with the KOR full agonist MP1104. This cavity plays an important role in determining either agonist or antagonist effects of the ligand. CONCLUSIONS: In conclusion, butorphanol is a partial KOR agonist in the G-protein activation pathway and a potent KOR full agonist in the beta-arrestin recruitment pathway. The structure analysis offers insights into the molecular mechanism of KOR interaction and activation by butorphanol. FAU - Ji, Jiafu AU - Ji J AD - From the Department of Anesthesiology, Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China. AD - Department of Anesthesiology and Critical Care, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania. FAU - Lin, Wenzhen AU - Lin W AD - Department of Anesthesiology and Critical Care, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania. AD - Department of Biochemistry and Molecular Biology, School of Preclinical Medicine, Guangxi Medical University, Nanning, Guangxi, China. FAU - Vrudhula, Amey AU - Vrudhula A AD - Department of Anesthesiology and Critical Care, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania. FAU - Xi, Jin AU - Xi J AD - Department of Anesthesiology and Critical Care, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania. FAU - Yeliseev, Alexei AU - Yeliseev A AD - Laboratory of Membrane Biochemistry & Biophysics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, Maryland. FAU - Grothusen, John R AU - Grothusen JR AD - Department of Anesthesiology and Critical Care, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania. FAU - Bu, Weiming AU - Bu W AD - Department of Anesthesiology and Critical Care, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania. FAU - Liu, Renyu AU - Liu R AD - Department of Anesthesiology and Critical Care, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania. LA - eng GR - R01 GM111421/GM/NIGMS NIH HHS/United States PT - Journal Article PT - Research Support, N.I.H., Extramural PT - Research Support, N.I.H., Intramural PL - United States TA - Anesth Analg JT - Anesthesia and analgesia JID - 1310650 RN - 0 (Analgesics, Opioid) RN - 0 (OPRK1 protein, human) RN - 0 (Receptors, Opioid, kappa) RN - 0 (beta-Arrestins) RN - QV897JC36D (Butorphanol) SB - IM MH - Analgesics, Opioid/chemistry/metabolism/*pharmacology/toxicity MH - Animals MH - Butorphanol/chemistry/metabolism/*pharmacology/toxicity MH - Cell Line, Tumor MH - Drug Partial Agonism MH - HEK293 Cells MH - Humans MH - Mice MH - Molecular Docking Simulation MH - Neurons/*drug effects/metabolism MH - Protein Binding MH - Protein Conformation MH - Receptors, Opioid, kappa/*agonists/chemistry/metabolism MH - Signal Transduction MH - Structure-Activity Relationship MH - beta-Arrestins/metabolism PMC - PMC7668422 MID - NIHMS1638204 COIS- The authors declare no conflicts of interest. EDAT- 2020/07/24 06:00 MHDA- 2020/11/18 06:00 PMCR- 2021/09/01 CRDT- 2020/07/24 06:00 PHST- 2020/07/24 06:00 [pubmed] PHST- 2020/11/18 06:00 [medline] PHST- 2020/07/24 06:00 [entrez] PHST- 2021/09/01 00:00 [pmc-release] AID - 00000539-202009000-00037 [pii] AID - 10.1213/ANE.0000000000005017 [doi] PST - ppublish SO - Anesth Analg. 2020 Sep;131(3):935-942. doi: 10.1213/ANE.0000000000005017.