title: Characterization of the Inward- and Outward-Facing Substrate Binding Sites of the Prokaryotic Aspartate Transporter, GltPh.
abstract: Crystal structures of the prokaryotic aspartate transporter, GltPh, have provided important insights into the mechanism of amino acid transport by GltPhand related eukaryotic members of the glutamate transporter family (SLC1A family). Identification of inhibitors of GltPhcan provide valuable tools for understanding the molecular basis for substrate and inhibitor specificity and selectivity of SLC1A members, but at present, few inhibitors of GltPhhave been identified. We have screened a collection of commercially available aspartate analogues and identified new transportable and nontransportable GltPhinhibitors. We have explored the inhibition profile of GltPhby utilizing a thiol modification assay that isolates sided populations of the transporters reconstituted in liposomes to determine if any aspartate analogues display a preference for either the inwardly or outwardly directed binding sites. Here, we have characterized several new inhibitors of GltPhand identified three β-carbon-substituted molecules that display a strong preference for the outwardly directed binding site of GltPh.
authors.affiliation: Transporter Biology Group, Discipline of Pharmacology, Sydney Medical School, University of Sydney , Sydney, New South Wales 2006, Australia.
authors.forename: Benjamin C
authors.initials: BC
authors.lastname: McIlwain
authors.affiliation: Transporter Biology Group, Discipline of Pharmacology, Sydney Medical School, University of Sydney , Sydney, New South Wales 2006, Australia.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Vandenberg
authors.affiliation: Transporter Biology Group, Discipline of Pharmacology, Sydney Medical School, University of Sydney , Sydney, New South Wales 2006, Australia.
authors.forename: Renae M
authors.initials: RM
authors.lastname: Ryan
mesh_terms: D027322:Amino Acid Transport System X-AG / Q000737:chemistry / Q000378:metabolism*; D001224:Aspartic Acid / Q000378:metabolism*; D001665:Binding Sites
chemical_list: D027322:Amino Acid Transport System X-AG; D001224:Aspartic Acid