The octahydroindene carboxyl substructure from dihydrobetulinic acid is essential to inhibit topoisomerase IB from Leishmania donovani

Abstract

The dihydrobetulinic acid is a known competitive inhibitor of topoisomerase IB from Leishmania donovani, a validated target for developing new antileishmanial drugs. However, its binding mode and interaction pocket have not been established yet. We combined docking and molecular dynamics simulations to identify the most probable binding pocket. Our best model strongly suggests a cavity involving the residues arginine 314 and arginine 410 from chain A, and the catalytic tyrosine 222 from chain B as the interaction site and a substructure of this terpene inhibitor as essential for the process of molecular recognition. Then, a new class of inhibitors with increased affonity could be designed by structure-based approaches.