Competitive mode and site of interaction of ticagrelor at the human platelet P2Y12 -receptor
Autor: | Kristina Hoffmann, Jens Straßburger, D. A. Lutz, Younis Baqi, I. von Kügelgen, Christa E. Müller |
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Rok vydání: | 2014 |
Předmět: |
Agonist
Ticagrelor Adenosine medicine.drug_class CHO Cells Pharmacology Biology Response Elements Transfection Binding Competitive P2Y12 Cricetulus Genes Reporter medicine Cyclic AMP Animals Humans Binding site Receptor Mode of action Luciferases Binding Sites Dose-Response Relationship Drug Chinese hamster ovary cell Colforsin Antagonist Hematology Thionucleotides Receptors Purinergic P2Y12 Adenosine Diphosphate Gene Expression Regulation Mutation Purinergic P2Y Receptor Antagonists Purinergic P2Y Receptor Agonists Platelet Aggregation Inhibitors medicine.drug Protein Binding |
Zdroj: | Journal of thrombosis and haemostasis : JTH. 12(11) |
ISSN: | 1538-7836 |
Popis: | SummaryBackground The G-protein-coupled P2Y12-receptor plays a crucial role in platelet aggregation. Recently, ticagrelor was licensed as the first perorally active and reversible P2Y12-receptor antagonist. Objective The present study investigated the site and the antagonistic mode of action of ticagrelor at wild-type or mutant human P2Y12-receptors. Methods Recombinant wild-type or mutant human P2Y12-receptors were stably expressed in Chinese hamster ovary Flp-In cells. Receptor function was assessed by quantification of ADP- and 2-methylthio-ADP-mediated inhibition of forskolin-induced cellular cAMP production either using a [3H]cAMP-radioaffinity assay or a cAMP response element-driven luciferase reporter gene assay. Results The natural agonist ADP inhibited forskolin-induced cAMP formation at the wild-type P2Y12-receptor with a lower potency (EC50 209 nm) than the synthetic agonist 2-methylthio-ADP (EC50 1.0 nm). Ticagrelor shifted the concentration-response curves of both agonists in a parallel and surmountable manner to the right. Increasing concentrations of ticagrelor caused increasing shifts. Schild-plot analysis revealed pA2 values of 8.85 for ticagrelor against ADP, and 8.69 against 2-methylthio-ADP, and slopes of the regression lines not different from unity. In cells expressing a recombinant C194A5.43-mutant P2Y12-receptor construct, ticagrelor lost antagonistic potency when tested against ADP or 2-methylthio-ADP. Conclusions The experiments reveal a surmountable and competitive mode of antagonism of ticagrelor at P2Y12-receptors activated by either the natural agonist ADP or the synthetic agonist 2-methylthio-ADP. Cys1945.43 is likely to be involved in the interaction of ticagrelor with ADP and 2-methylthio-ADP. The data give new insights into the site and mode of action of ticagrelor at the human P2Y12-receptor. |
Databáze: | OpenAIRE |
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