VIRTUAL SCREENING OF FDA-APPROVED DRUGS BY MOLECULAR DOCKING AND DYNAMICS SIMULATION TO RECOGNIZE POTENTIAL INHIBITORS AGAINST MYCOBACTERIUM TUBERCULOSIS ENOYL-ACYL CARRIER PROTEIN REDUCTASE ENZYME

Abstract

Objective: This in silico study is aimed at identification of new possible inhibitors against Mycobacterium tuberculosis InhA enzyme by screening a library of FDA-approved drugs. Methods: In this in silico study, a library of FDA-approved drugs was screened by molecular docking against the monomer of enoyl-acyl carrier protein reductase to recognize potential inhibitors. Then, those best drugs with minimum docking energy were subjected to molecular dynamics simulation. Results: Out of the top ten docking hits, only revefenacin was able to maintain the closet proximity to InhA enzyme binding pocket during the two rounds of dynamics simulation. Analysis of molecular dynamics (MD) simulation data indicated that the antimuscarinic drug revefenacin has a ligand movement Root-Mean-Square Deviation (RMSD) that didn’t exceed 4 Angstrom. Also, in this MD study, revefenacin has a superior binding energy of -35.59 Kcal/mol as compared to -13.88 Kcal/mol for the other hit ergotamine. These favorable MD simulation records for revefenacin can be explained by its ability to continuously interact with enzyme binding pocket by two hydrogen bonds. Conclusion: We report that the antimuscarinic drug revefenacin may have the potential to inhibit the enoyl-acyl carrier protein reductase for Mycobacterium tuberculosis. However, these preliminary results must be further evaluated by in vitro and in vivo studies.