Integrative analysis of dynamic allostery and hydration networks in p38α Map kinase using Nuclear Magnetic Resonance and molecular dynamics simulations

Abstract

Protein kinases are major therapeutic targets, but the high conservation of their ATP-binding sites limits the development of selective inhibitors. This has increased interest in kinase conformational ensembles and long-range allosteric communication as alternative routes for selective modulation. Here, p38α MAP kinase was used as a model system to investigate how dynamic communication across the kinase domain regulates structure, stability, hydration, and ligand response. Large-scale molecular dynamics simulations combined with dynamical network analysis identified key residues that mediate communication between the N- and C-lobes and connect functional regions including the activation loop, hinge, lipid-binding domain, and cryptic allosteric pocket. These predictions were experimentally tested using NMR spectroscopy, biochemical activity assays, and selected p38α mutants in the presence and absence of an active-site inhibitor. A second part of the study focused on Asp168, the conserved aspartate of the DFG motif, which is essential for catalytic activity and activation-loop organisation. Mutation of this residue induced long-range effects beyond the active site, altering thermal stability, residue-level flexibility, cross-lobe correlations, ligand behaviour, and hydration networks in distal pockets. In particular, D168A reorganised water-associated signals around the activation loop and lipid pocket, obtained through experimental solution and solid-state NMR and bolstered by molecular dynamics simulations, demonstrating that perturbation of a catalytic DFG residue can reshape both protein dynamics and solvent organisation across the kinase domain. Together, these results provide atomistic insight into how local perturbations propagate through p38α to regulate allosteric communication. This integrated computational and experimental structural-biology framework to understand the dynamic allostery functioning within the kinase may guide the rational design of selective allosteric kinase modulators that exploit dynamic and hydration-mediated regulatory networks rather than conserved active-site features alone.