Screening for novel modulators of hP2X2 and hP2X4 receptors using an in silico approach

Purinergic P2X receptors (P2XR) are activated by ATP, with 7 different subunits capable of forming homo- or heterotrimeric channels. Widely expressed in the nervous system, P2XR have been implicated in neurological diseases, such as Alzheimer's disease, where overexpression of P2X2, P2X4 and P2X7 is observed. Despite decades of research into their function and structure, few P2XR structures and specific negative modulators have been described. Human P2X2 (hP2X2) and P2X4 (hP2X4) structures are not available, posing challenges for designing more effective and specific modulators.In this study, we used models of hP2X2 and hP2X4 based on the zebra fish P2X4 (zP2X4) structure to perform in silico screening for putative modulator molecules. For the massive docking protein-ligand simulations the interaction grids were positioned in the ATP binding site, identified through multiple sequence alignments with the zP2X4 and the rat P2X2.The in silico screening was performed using molecules from the MolPort database. 1,070,608 compounds with molecular weights between 400 and 700kDa were initially prepared and their physicochemical properties calculated. Generated complexes were analyzed and ranked based on docking scores and binding free energies (DGbind). Promising candidates with a DGbind lower or comparable to that achieved by ATP were selected from various chemical families for in vitro testing.In conclusion, our in silico approach utilizing homology models of the hP2X2 and hP2X4 proves to be a viable tool for screening novel selective and effective compounds with potential modulation activity.ANID FONDECYT Postdoctoral 3230515 to GPA, ANID FONDECYT 11221211 to CFB