title: Synthesis, Biological Evaluation, and Utility of Fluorescent Ligands Targeting the μ-Opioid Receptor.
abstract: Fluorescently labeled ligands are useful pharmacological research tools for studying receptor localization, trafficking, and signaling processes via fluorescence imaging. They are also employed in fluorescent binding assays. This study is centered on the design, synthesis, and pharmacological evaluation of fluorescent probes for the opioid receptors, for which relatively few non-peptidic fluorescent probes currently exist. The known μ-opioid receptor (MOR) partial agonist, buprenorphine, was structurally elaborated to include an amidoalkylamine linker moiety that was coupled with a range of fluorophores to afford new fluorescent probes. All compounds proved to be selective MOR antagonists. Confocal fluorescence microscopy studies revealed that the probe incorporating a sulfonated cyanine-5 fluorophore was the most appropriate for imaging studies. This ligand was subsequently employed in an automated fluorescence-based competition binding assay, allowing the pKi values of several well-known opioid ligands to be determined. Thus, this new probe will prove useful in future studies of MOR receptor pharmacology.
authors.forename: Luke S
authors.initials: LS
authors.lastname: Schembri
authors.affiliation: Cell Signaling Research Group, School of Life Sciences, Queen's Medical Centre, University of Nottingham , Nottingham NG7 2UH, U.K.
authors.forename: Leigh A
authors.initials: LA
authors.lastname: Stoddart
authors.affiliation: Cell Signaling Research Group, School of Life Sciences, Queen's Medical Centre, University of Nottingham , Nottingham NG7 2UH, U.K.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Briddon
authors.affiliation: School of Pharmacy, Centre for Biomolecular Sciences, University of Nottingham , Nottingham NG7 2RD, U.K.
authors.forename: Barrie
authors.initials: B
authors.lastname: Kellam
authors.forename: Meritxell
authors.initials: M
authors.lastname: Canals
authors.forename: Bim
authors.initials: B
authors.lastname: Graham
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Scammells
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D002047:Buprenorphine / Q000031:analogs & derivatives* / Q000737:chemistry* / Q000494:pharmacology; D016466:CHO Cells; D003412:Cricetulus; D005456:Fluorescent Dyes / Q000737:chemistry* / Q000494:pharmacology; D057809:HEK293 Cells; D006801:Humans; D008024:Ligands; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D010766:Phosphorylation; D011869:Radioligand Assay; D017450:Receptors, Opioid, mu / Q000037:antagonists & inhibitors / Q000378:metabolism*; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
chemical_list: D005456:Fluorescent Dyes; D008024:Ligands; D017450:Receptors, Opioid, mu; D002047:Buprenorphine; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3