Estudo teórico das interações entre inibidores da inha, enoil acp redutase do mycobacterium tuberculosis

Abstract

Isoniazid is the oldest, cheapest and most effective synthetic prodrug of the first line of treatment for Tuberculosis. It should be activated by the Mycobacterium tuberculosis catalase-peroxidase, KatG, which produces an isonicotinoyl-NADH adduct, INNADH, which targets the M. tuberculosis Enoyl-ACP reductase protein, InhA, in order to disrupt the synthesis chain of mycolic acids. Resistance to isoniazid alone or in combination with other drugs is one of the most common forms of resistant tuberculosis and poses a threat to the control of this disease. In this context, triclosan (TCL) appears as an alternative inhibitor of the synthesis of mycolic acids, since it is also specific to InhA. This study aims to evaluate the interactions of inhibitors of InhA through Molecular Dynamics Simulation (DM) and propose possible new inhibitors for this enzyme. The system used in this work was captured from the database PDB, code 4TRO. Eight ligands, NADH, INNADH, and the TCL, P31, P41, P52, P61, P72 and P80 derivatives were evaluated. In the lower region of the active site of InhA were more frequent π charge stacks made by PHE41 and PHE97 with the ligands NADH, INADH, P80, P31, P72, however P41 made a hydrogen bond (LH) with PHE41. In the central region of the active site, residues such as A GLY96, SER20 and ILE21 did LH with NADH, INNADH, P31, P41 and P80. In relation to the upper region of the InhA site. The PHE149 performed EC-π with the INNADH and P41. Already in P31 was an LH with this residue and in P80 the energies are favorable for interaction. The free energies of each system presented in descending order are INNADH (-72,038 kcal / mol), P80 (-45,841 kcal / mol), NADH (- 41,463 kcal / mol), P41 (-40,178 kcal / mol), P31 (-30.614 kcal / mol), p52 (-19.475 kcal / mol) and P61 (-12.297 kcal / mol). These results highlight P80 and P41 as promising candidates for M. tuberculosis mycolic acid synthesis inhibitors, since being an energy profile is competitive with the values shown by NADH.