Molecular modeling of three-dimensional structure of hTRPV4 protein and experimental verification of its antagonist binding sites

Abstract

The transient receptor potential vanilloid type 4 (TRPV4) is a polymodal receptor. Antagonists of human TRPV4 (hTRPV4) represent a novel therapeutic approach for acute lung injury (ALI). However, the discovery of various hTRPV4 antagonists has been difficult due to the unavailability of 3D-structure of hTRPV4 protein. We constructed the 3D-structure of hTRPV4 protein by homology modelling, and the binding pocket of antagonist with hTRPV4 was predicted for the first time. The pocket was consistent with the same subfamily rabbit TRPV5. The detailed interactions of different protein-ligand complexes were calculated by molecular docking and molecular dynamics (MD) simulation, and the outcome revealed the rationality of the binding pocket. Based on the docking and MD results of this model and the structure of compound A2, a TRPV4 antagonist reported in literature, two small molecular compounds, B1 and B2, were designed and synthesized as hTRPV4 antagonists. The results of biological evaluation in vitro showed that these compounds have good inhibitory activity on hTRPV4. Moreover, the results were in good agreement with those predicted by molecular simulation, which in turn suggested that the modeling 3D structure and the predicted active sites of hTRPV4 are reasonable and reliable. The compound B2, with novel structure and potent inhibitory activity against hTRPV4, can be a promising lead compound for discovering new hTRPV4 antagonists in the future.