Expanding the therapeutic landscape of <scp>PDE10A</scp> inhibition through alchemical absolute binding free energy calculations and in‐vitro evaluation
Bhanu Sharma, Rahul singh, Ashish Kumar, Pralay Das, Rituraj Purohit
Abstract
In preclinical models, Phosphodiesterase-10A (PDE10A) inhibition has shown efficacy for Parkinson's and Huntington's diseases and is potentially a therapeutic approach for schizophrenia. In this study, computational approaches were employed to identify selective PDE10A inhibitors from a series of olefinated benzosuberene analogues. The molecular interactions and docking scores of the selected molecules were compared with three different co-crystal inhibitors of PDE10A. Molecular dynamics (MD) simulations confirmed the stability of the screened hit molecules with PDE10A, and AMKPD-52 was found to uniquely interact with the selectivity pocket residue Tyr-683. Further refinement using steered MD simulations and umbrella sampling simulations with a total simulation time of ~72 μs reinforced AMKPD-52 as the potential lead molecule. Absolute binding free energy calculations performed using multistate Bennett acceptance ratio method consistently ranked AMKPD-52 as the potential lead molecule for PDE10A inhibition. Experimental evaluation revealed an IC₅₀ value of 11.52 μM for AMKPD-52, confirming its inhibitory activity against PDE10A. Although the binding affinity and potency were modest compared to the reference inhibitor TAK-063, the natural origin and straightforward synthetic tractability of AMKPD-52 make it an attractive candidate for further medicinal chemistry optimization. These findings warrant in vivo validation to assess the therapeutic potential of AMKPD-52 in PDE10A-targeted interventions.