title: A fluorescence displacement assay for antidepressant drug discovery based on ligand-conjugated quantum dots.
abstract: The serotonin (5-hydroxytryptamine, 5-HT) transporter (SERT) protein plays a central role in terminating 5-HT neurotransmission and is the most important therapeutic target for the treatment of major depression and anxiety disorders. We report an innovative, versatile, and target-selective quantum dot (QD) labeling approach for SERT in single  Xenopus  oocytes that can be adopted as a drug-screening platform. Our labeling approach employs a custom-made, QD-tagged indoleamine derivative ligand, IDT318, that is structurally similar to 5-HT and accesses the primary binding site with enhanced human SERT selectivity. Incubating QD-labeled oocytes with paroxetine (Paxil), a high-affinity SERT-specific inhibitor, showed a concentration- and time-dependent decrease in QD fluorescence, demonstrating the utility of our approach for the identification of SERT modulators. Furthermore, with the development of ligands aimed at other pharmacologically relevant targets, our approach may potentially form the basis for a multitarget drug discovery platform.
authors.affiliation: Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37232, United States.
authors.forename: Jerry C
authors.initials: JC
authors.lastname: Chang
authors.forename: Ian D
authors.initials: ID
authors.lastname: Tomlinson
authors.forename: Michael R
authors.initials: MR
authors.lastname: Warnement
authors.forename: Hideki
authors.initials: H
authors.lastname: Iwamoto
authors.forename: Louis J
authors.initials: LJ
authors.lastname: DeFelice
authors.forename: Randy D
authors.initials: RD
authors.lastname: Blakely
authors.forename: Sandra J
authors.initials: SJ
authors.lastname: Rosenthal
mesh_terms: D000588:Amines / Q000737:chemistry*; D000818:Animals; D000928:Antidepressive Agents / Q000737:chemistry / Q000494:pharmacology*; D001665:Binding Sites / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D055808:Drug Discovery; D005453:Fluorescence; D006801:Humans; D008024:Ligands; D009865:Oocytes / Q000737:chemistry / Q000187:drug effects; D017374:Paroxetine / Q000737:chemistry / Q000494:pharmacology*; D045663:Quantum Dots; D050486:Serotonin Plasma Membrane Transport Proteins / Q000737:chemistry / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D013329:Structure-Activity Relationship; D013997:Time Factors; D014981:Xenopus
chemical_list: D000588:Amines; D000928:Antidepressive Agents; D008024:Ligands; D050486:Serotonin Plasma Membrane Transport Proteins; D017374:Paroxetine