%0 Journal Article %A Philipp Schmidt %A Lars Ritscher %A Elizabeth Nguyen Dong %A Thomas Hermsdorf %A Maxi Coster %A Doreen Wittkopf %A Jens Meiler %A Torsten Schoneberg %T Identification of Determinants Required for Agonistic and Inverse Agonistic Ligand Properties at the ADP Receptor P2Y12 %D 2012 %R 10.1124/mol.112.082198 %J Molecular Pharmacology %P mol.112.082198 %X The ADP receptor P2Y12 belongs to the superfamily of G protein-coupled receptors (GPCRs) and its activation triggers platelet aggregation. Therefore, potent antagonists, e.g. clopidogrel, are of high clinical relevance in prophylaxis and treatment of thromboembolic events. P2Y12 displays an elevated basal activity in vitro and as such, inverse agonists may be therapeutically beneficial compared to antagonists. Only a few inverse agonists of P2Y12 have been described. To expand this limited chemical space and improve understanding of structural determinants of inverse agonist-receptor interaction, we screened an adenosine nucleotide library for lead structures using wild type (WT) human P2Y12 and 28 constitutively active mutants. We found that ATP and ATP derivatives are agonists at P2Y12. The potency at P2Y12 was 2-(methylthio)-ADP > 2-(methylthio)-ATP > ADP > ATP. Determinants required for agonistic ligand activity were identified. Molecular docking studies revealed a binding pocket for the ATP derivatives that is bordered by transmembrane helices 3, 5, 6 and 7 in the human P2Y12, with Y105, E188, R256, Y259 and K280 playing a particularly important role in ligand interaction. N-methyl-anthraniloyl modification at the 3’ OH of the 2’deoxiribose leads to ligands (mant-dATP, mant-dADP) with inverse agonist activity. Inverse agonist activity of mant-dATP was found at the WT human P2Y12 and half of the constitutive active P2Y12 mutants. Our study showed that, in addition to ADP and ATP, other ATP derivatives are not only ligands of P2Y12 but also agonists. Modification of the ribose within ATP can result in inverse activity of ATP-derived ligands. %U https://molpharm.aspetjournals.org/content/molpharm/early/2012/10/23/mol.112.082198.full.pdf