Structure based identification of novel inhibitors against ATP synthase of Mycobacterium tuberculosis: A combined in silico and in vitro study

Abstract

The shortcomings of conventional tuberculosis treatments resulting from the development of drug resistance in Mycobacterium tuberculosis drive a need for the formulation of novel therapeutic agents. The diarylquinoline class of drugs such as bedaquiline was recently approved for the treatment of multidrug-resistant strains of tuberculosis, primarily targeting c and ε subunits of the ATP synthases. Yet resistance to bedaquiline has already been reported. Therefore, Rv1311 was used as the target for the identification of possible inhibitors against the M. tuberculosis. The structure of Rv1311 was predicted and common feature pharmacophore models were generated which facilitated the identification of potential inhibitors in the ZINC database. The activities of the selected molecules were compared with known inhibitors of the ATP synthase using quantitative structure-activity relationship. The ZINC classified inhibitors showed comparable predicted activities with that of known inhibitors. Furthermore, the inhibitory behavior of the studied drug molecules was experimentally determined using in vitro techniques and showed the minimum inhibitory concentration as low as 25 μM. The resulted outcomes provide a deeper insight into the structural basis of Rv1311 inhibitions and can facilitate the process of drug design against tuberculosis.

Keywords: ATP synthase; Molecular docking; Molecular dynamic simulations; Mycobacterium tuberculosis; Pharmacophore modeling.