Thienopyrimidine amide analogs target MmpL3 in .

OBJECTIVES

The identification of novel agents with mechanisms of action distinct from those currently utilized in tuberculosis treatment remains a significant challenge. The mycobacterial protein MmpL3 has emerged as a promising drug target due to its essential role in the synthesis of the cell wall of . We previously identified novel thienopyrimidine amides with good anti-tubercular activity.

METHODS

We profiled a subset of thienopyrimidine amides determining activity against intracellular bacteria and bactericidal activity against replicating bacteria. We ran assays to determine mode of action by measuring cell wall stress, ATP production, and bacterial cytological profiling. We determined activity against a strain of M. tuberculosis with mutations in MmpL3. We isolated and sequenced resistant mutants.

RESULTS

We tested five analogs against a strain of with mutations in MmpL3 and determined that they lost potency. Analogs induced P, a reporter for cell wall stress, and led to an ATP boost characteristic of cell wall inhibitors. Bacterial cytological profiling of a representative compound revealed a morphological profile consistent with other MmpL3 inhibitors.

CONCLUSIONS

Together, our data support MmpL3 as the most probable drug target for the TPA analogs and add to the growing list of scaffolds that can inhibit this vulnerable transporter.