Each year, millions of people worldwide contract tuberculosis (TB), the deadliest infection. The spread of infections with drug-resistant strains of Mycobacterium tuberculosis (Mtb) that are refractory to treatment poses a major global challenge. A major cause of resistance to antitubercular drugs of last resort, aminoglycosides, is overexpression of the Eis (enhanced intracellular survival) enzyme of Mtb, which inactivates aminoglycosides by acetylating them. We showed previously that this inactivation of aminoglycosides could be overcome by our recently reported Eis inhibitors that are currently in development as potential aminoglycoside adjunctive therapeutics against drug-resistant TB. To interrogate the robustness of the Eis inhibitors, we investigated the enzymatic activity of Eis and its inhibition by Eis inhibitors from three different structural families for nine single-residue mutants of Eis, including those found in the clinic. Three engineered mutations of the substrate binding site, D26A, W36A, and F84A, abolished inhibitor binding while compromising Eis enzymatic activity 2- to 3-fold. All other Eis mutants, including clinically observed ones, were potently inhibited by at least one inhibitor. This study helps position us one step ahead of Mtb resistance to Eis inhibitors as they are being developed for TB therapy.
|Number of pages||7|
|Journal||ACS Infectious Diseases|
|State||Published - Jun 19 2019|
Bibliographical noteFunding Information:
This study was funded by a National Institutes of Health (NIH) grant AI090048 (to S.G.-T.) and startup funds from the College of Pharmacy at the University of Kentucky (to S.G.-T. and O.V.T.). We thank the staff of sector 22 (SER-CAT) of the Advanced Photon Source at the Argonne National Laboratories for their assistance with the remote X-ray diffraction data collection. The beamline use was supported, in part, by the Center for Structural Biology at the University of Kentucky.
Copyright © 2019 American Chemical Society.
- enzyme inhibitor
ASJC Scopus subject areas
- Infectious Diseases