title: Fragment screening of GPCRs using biophysical methods: identification of ligands of the adenosine A(2A) receptor with novel biological activity.
abstract: Fragment-based drug discovery (FBDD) has proven a powerful method to develop novel drugs with excellent oral bioavailability against challenging pharmaceutical targets such as protein-protein interaction targets. Very recently the underlying biophysical techniques have begun to be successfully applied to membrane proteins. Here we show that novel, ligand efficient small molecules with a variety of biological activities can be found by screening a small fragment library using thermostabilized (StaR) G protein-coupled receptors (GPCRs) and target immobilized NMR screening (TINS). Detergent-solubilized StaR adenosine A(2A) receptor was immobilized with retention of functionality, and a screen of 531 fragments was performed. Hits from the screen were thoroughly characterized for biochemical activity using the wild-type receptor. Both orthosteric and allosteric modulatory activity has been demonstrated in biochemical validation assays. Allosteric activity was confirmed in cell-based functional assays. The validated fragment hits make excellent starting points for a subsequent hit-to-lead elaboration program.
authors.affiliation: ZoBio BV, Leiden 2300RA, The Netherlands.
authors.forename: Dan
authors.initials: D
authors.lastname: Chen
authors.forename: James C
authors.initials: JC
authors.lastname: Errey
authors.forename: Laura H
authors.initials: LH
authors.lastname: Heitman
authors.forename: Fiona H
authors.initials: FH
authors.lastname: Marshall
authors.forename: Adriaan P
authors.initials: AP
authors.lastname: Ijzerman
authors.forename: Gregg
authors.initials: G
authors.lastname: Siegal
mesh_terms: D000495:Allosteric Site; D000818:Animals; D001703:Biophysics; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D006801:Humans; D008024:Ligands; D019906:Nuclear Magnetic Resonance, Biomolecular; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism*; D018047:Receptors, Purinergic P1 / Q000378:metabolism*
chemical_list: D008024:Ligands; D043562:Receptors, G-Protein-Coupled; D018047:Receptors, Purinergic P1