Probing Hydration Patterns in Class-A GPCRs via Biased MD: The A_2A Receptor

Herein, we present a new computational approach for analyzing hydration patterns in biomolecular systems. This protocol aims to efficiently identify regions where structural waters may be located and, in the case of protein-ligand binding, where displacing one or more water molecules could be advantageous in terms of affinity and/or residence time. We validated our approach on the adenosine A_2A receptor, a target of significant pharmaceutical relevance. The results of the approach are enriched with an extensive analysis of hydration in A_2A and other members of the A-family of GPCRs using available crystallographic evidence and reviewing existing literature. As per the protein-ligand complex case, we conducted a more detailed study of a series of triazine analogues inhibiting A_2A. The proposed approach provides results in good agreement with existing data and offers interpretability and simple and fast applicability.