title: Structural and energetic effects of A2A adenosine receptor mutations on agonist and antagonist binding.
abstract: To predict structural and energetic effects of point mutations on ligand binding is of considerable interest in biochemistry and pharmacology. This is not only useful in connection with site-directed mutagenesis experiments, but could also allow interpretation and prediction of individual responses to drug treatment. For G-protein coupled receptors systematic mutagenesis has provided the major part of functional data as structural information until recently has been very limited. For the pharmacologically important A(2A) adenosine receptor, extensive site-directed mutagenesis data on agonist and antagonist binding is available and crystal structures of both types of complexes have been determined. Here, we employ a computational strategy, based on molecular dynamics free energy simulations, to rationalize and interpret available alanine-scanning experiments for both agonist and antagonist binding to this receptor. These computer simulations show excellent agreement with the experimental data and, most importantly, reveal the molecular details behind the observed effects which are often not immediately evident from the crystal structures. The work further provides a distinct validation of the computational strategy used to assess effects of point-mutations on ligand binding. It also highlights the importance of considering not only protein-ligand interactions but also those mediated by solvent water molecules, in ligand design projects.
authors.affiliation: Department of Cell and Molecular Biology, Uppsala University, Biomedical Center, Uppsala, Sweden.
authors.forename: Henrik
authors.initials: H
authors.lastname: Keränen
authors.affiliation: Department of Cell and Molecular Biology, Uppsala University, Biomedical Center, Uppsala, Sweden.
authors.forename: Hugo
authors.initials: H
authors.lastname: Gutiérrez-de-Terán
authors.affiliation: Department of Cell and Molecular Biology, Uppsala University, Biomedical Center, Uppsala, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Åqvist
mesh_terms: D058908:Adenosine A2 Receptor Agonists / Q000737:chemistry* / Q000378:metabolism*; D058917:Adenosine A2 Receptor Antagonists / Q000737:chemistry* / Q000378:metabolism*; D019830:Adenosine-5'-(N-ethylcarboxamide) / Q000737:chemistry / Q000378:metabolism; D001665:Binding Sites; D006801:Humans; D008024:Ligands; D050505:Mutant Proteins / Q000737:chemistry; D009154:Mutation / Q000235:genetics*; D043705:Receptor, Adenosine A2A / Q000737:chemistry* / Q000378:metabolism*; D013816:Thermodynamics; D014227:Triazines / Q000737:chemistry / Q000378:metabolism; D014230:Triazoles / Q000737:chemistry / Q000378:metabolism
chemical_list: D058908:Adenosine A2 Receptor Agonists; D058917:Adenosine A2 Receptor Antagonists; D008024:Ligands; D050505:Mutant Proteins; D043705:Receptor, Adenosine A2A; D014227:Triazines; D014230:Triazoles; C097270:ZM 241385; D019830:Adenosine-5'-(N-ethylcarboxamide)