Developing anti-tuberculosis dual-target inhibitors of AARSs
Adressing Multidrug Resistance through Dual Inhibition of LeuRS and MetRS in Mycobacterium tuberculosis
leucyl-tRNA synthetase (LeuRS) and methionyl-tRNA synthetase (MetRS)
Background
Effective treatment of tuberculosis is challenged by the rapid development of multidrug resistance.
Here, we experimentally verify a hypothesis of overcoming the resistance by simultaneous targeting of two structurally related Mycobacterium tuberculosis target proteins: leucyl-tRNA synthetase (LeuRS) and methionyl-tRNA synthetase (MetRS) by a single inhibitor.
Methodology
Pocket prediction using a proprietary algorithm.
Molecular docking into predicted AARSs active pockets.
The best ranking novel compounds were selected for experimental potency assessment.
LeuRS and MetRS were expressed in E. coli cells and purified.
Inhibition was assessed by the standard aminoacylation assay.
The antimicrobial effect of inhibitors (MIC, IC50, IC90) was determined.
In vitro cytotoxicity was assessed on HEK293 and HepG2 cells using the MTT assay.
Results
270 compounds were selected for testing inhibitory activity toward LeuRS.
5 compounds demonstrated significantly better inhibitory activity toward MtLeuRS than toward human LeuRS (HsLeuRS).
Compound 1 has the best cell permeability and inhibits growth of pathogens
Series expansion and docking of compound 1 derivatives was performed.
35 compounds were selected and tested.
4 of them showed dual-target activity.
The compound 6 showed anti-tubercular whole cell activity against Mtb H37Rv in vitro bioassays as well as low cytotoxicity to HEK293 and HepG2 human cell lines.
