Sodium Ion Binding Pocket Mutations and Adenosine A_2AReceptor Function

Abstract

Recently we identified a sodium ion binding pocket in a highresolution structure of the human adenosine A 2A receptor. In the present study we explored this binding site through site-directed mutagenesis and molecular dynamics simulations. Amino acids in the pocket were mutated to alanine, and their influence on agonist and antagonist affinity, allosterism by sodium ions and amilorides, and receptor functionality was explored. Mutation of the polar residues in the Na 1 pocket were shown to either abrogate (D52A 2.50 and N284A7.49

Membrane potentials regulating GPCRs: insights from experiments and molecular dynamics simulations

“…Moreover, previous MD studies on the δ-OR without applied voltage have demonstrated the internal Na + ion to be mobile, and able to leave the receptor under the influence of an applied force [46]. Importantly, it has also been shown that small organic cations such as amiloride can replace Na + in the pocket under low Na + concentration, exerting an allosteric effect similar to Na + [47 •• ]. It is therefore possible that other cations can undergo analogous movements within the pocket upon depolarisation, depending on experimental conditions, and give rise to comparable gating charges [32].…”

How Do Short Chain Nonionic Detergents Destabilize G-Protein-Coupled Receptors?

“…The receptor we have used for this study, the human adenosine A 2A receptor (A 2A R), was chosen because its stability in lipid bilayers has already been thoroughly studied by MD simulations, both for the wild type receptor and engineered thermostable mutant in different conformations. 32-34 In addition, there is a wealth of biochemical data on A 2A R stability, in particular in different detergent solutions. 35-37 A 2A R has been crystallized by a number of groups using three different strategies (thermostabilization 38,39 , T4 lysozyme fusion 40,41 and antibody binding 42 ) to facilitate the formation of well-ordered crystals.…”

The role of experimental and computational structural approaches in 7TM drug discovery

“…(2015) 10(10) allosteric modulator, was docked into the sodium-ion-binding site. This and follow-up studies [61][62][63][64][65] on related ligands support the possible use of this region as a drug-discovery target. Indeed, the X-ray structure of a class C protein, mGluR5, with the bound inhibitor mavoglurant shows this ligand to overlap with the sodium ion, with the rest of the ligand located further towards the EC region.…”