title: Identification of the First Highly Subtype-Selective Inhibitor of Human GABA Transporter GAT3.
abstract: Screening a library of small-molecule compounds using a cell line expressing human GABA transporter 3 (hGAT3) in a [(3)H]GABA uptake assay identified isatin derivatives as a new class of hGAT3 inhibitors. A subsequent structure-activity relationship (SAR) study led to the identification of hGAT3-selective inhibitors (i.e., compounds 20 and 34) that were superior to the reference hGAT3 inhibitor, (S)-SNAP-5114, in terms of potency (low micromolar IC50 values) and selectivity (>30-fold selective for hGAT3 over hGAT1/hGAT2/hBGT1). Further pharmacological characterization of compound 20 (5-(thiophen-2-yl)indoline-2,3-dione) revealed a noncompetitive mode of inhibition at hGAT3. This suggests that this compound class, which has no structural resemblance to GABA, has a binding site different from the substrate, GABA. This was supported by a molecular modeling study that suggested a unique binding site that matched the observed selectivity, inhibition kinetics, and SAR of the compound series. These compounds are the most potent GAT3 inhibitors reported to date that provide selectivity for GAT3 over other GABA transporter subtypes.
authors.forename: Maria
authors.initials: M
authors.lastname: Damgaard
authors.forename: Anas
authors.initials: A
authors.lastname: Al-Khawaja
authors.forename: Stine B
authors.initials: SB
authors.lastname: Vogensen
authors.affiliation: Department of Pharmaceutical Chemistry, University of Vienna , Althanstrasse 14, A-1090 Vienna, Austria.
authors.forename: Andreas
authors.initials: A
authors.lastname: Jurik
authors.forename: Maarten
authors.initials: M
authors.lastname: Sijm
authors.forename: Maria E K
authors.initials: ME
authors.lastname: Lie
authors.forename: Mathias I
authors.initials: MI
authors.lastname: Bæk
authors.forename: Emil
authors.initials: E
authors.lastname: Rosenthal
authors.forename: Anders A
authors.initials: AA
authors.lastname: Jensen
authors.affiliation: Department of Pharmaceutical Chemistry, University of Vienna , Althanstrasse 14, A-1090 Vienna, Austria.
authors.forename: Gerhard F
authors.initials: GF
authors.lastname: Ecker
authors.forename: Bente
authors.initials: B
authors.lastname: Frølund
authors.forename: Petrine
authors.initials: P
authors.lastname: Wellendorph
authors.forename: Rasmus P
authors.initials: RP
authors.lastname: Clausen
mesh_terms: D000818:Animals; D000840:Anisoles / Q000737:chemistry / Q000494:pharmacology; D001665:Binding Sites; D016466:CHO Cells; D003412:Cricetulus; D050485:GABA Plasma Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D058805:GABA Uptake Inhibitors / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D007510:Isatin / Q000031:analogs & derivatives; D007700:Kinetics; D056004:Molecular Dynamics Simulation; D015394:Molecular Structure; D009557:Nipecotic Acids / Q000737:chemistry / Q000494:pharmacology; D013329:Structure-Activity Relationship; D014162:Transfection; D014316:Tritium; D005680:gamma-Aminobutyric Acid / Q000737:chemistry / Q000378:metabolism
chemical_list: C092337:1-(2-(tris(4-methoxyphenyl)methoxy)ethyl)-3-piperidinecarboxylic acid; D000840:Anisoles; D050485:GABA Plasma Membrane Transport Proteins; D058805:GABA Uptake Inhibitors; D009557:Nipecotic Acids; C493416:SLC6A11 protein, human; D014316:Tritium; D005680:gamma-Aminobutyric Acid; D007510:Isatin
keywords: GABA uptake; hGAT3 selective; inhibitor; isatin; kinetics; noncompetitive