A small-molecule inhibitor of BamA impervious to efflux and the outer membrane permeability barrier.

Autor: Hart EM; Department of Molecular Biology, Princeton University, Princeton, NJ 08540., Mitchell AM; Department of Molecular Biology, Princeton University, Princeton, NJ 08540., Konovalova A; Department of Molecular Biology, Princeton University, Princeton, NJ 08540.; Department of Microbiology and Molecular Genetics, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030., Grabowicz M; Department of Molecular Biology, Princeton University, Princeton, NJ 08540.; Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA 30322.; Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322.; Division of Infectious Disease, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322., Sheng J; Department of Molecular Biology, Princeton University, Princeton, NJ 08540., Han X; Chemical Biology, Merck & Co., Inc., Kenilworth, NJ 07033., Rodriguez-Rivera FP; Chemical Biology, Merck & Co., Inc., Kenilworth, NJ 07033., Schwaid AG; Chemistry, Merck & Co., Inc., Boston, MA 02115., Malinverni JC; Infectious Disease, Merck & Co., Inc., West Point, PA 19486., Balibar CJ; Infectious Disease, Merck & Co., Inc., West Point, PA 19486., Bodea S; Chemistry, Merck & Co., Inc., Boston, MA 02115., Si Q; Pharmacology, Merck & Co., Inc., West Point, PA 19486., Wang H; Infectious Disease, Merck & Co., Inc., West Point, PA 19486., Homsher MF; Biologics and Vaccine Analytics, Merck & Co., Inc., West Point, PA 19486., Painter RE; Pharmacology, Merck & Co., Inc., West Point, PA 19486., Ogawa AK; Chemistry, Merck & Co., Inc., South San Francisco, CA 94080., Sutterlin H; Biology, Prokaryotics, Inc., Union, NJ 07083., Roemer T; Biology, Prokaryotics, Inc., Union, NJ 07083., Black TA; Infectious Disease, Merck & Co., Inc., West Point, PA 19486., Rothman DM; Chemical Biology, Merck & Co., Inc., Kenilworth, NJ 07033., Walker SS; Infectious Disease, Merck & Co., Inc., West Point, PA 19486., Silhavy TJ; Department of Molecular Biology, Princeton University, Princeton, NJ 08540; tsilhavy@princeton.edu.
Jazyk: angličtina
Zdroj: Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2019 Oct 22; Vol. 116 (43), pp. 21748-21757. Date of Electronic Publication: 2019 Oct 07.
DOI: 10.1073/pnas.1912345116
Abstrakt: The development of new antimicrobial drugs is a priority to combat the increasing spread of multidrug-resistant bacteria. This development is especially problematic in gram-negative bacteria due to the outer membrane (OM) permeability barrier and multidrug efflux pumps. Therefore, we screened for compounds that target essential, nonredundant, surface-exposed processes in gram-negative bacteria. We identified a compound, MRL-494, that inhibits assembly of OM proteins (OMPs) by the β-barrel assembly machine (BAM complex). The BAM complex contains one essential surface-exposed protein, BamA. We constructed a bamA mutagenesis library, screened for resistance to MRL-494, and identified the mutation bamA E470K BamA E470K restores OMP biogenesis in the presence of MRL-494. The mutant protein has both altered conformation and activity, suggesting it could either inhibit MRL-494 binding or allow BamA to function in the presence of MRL-494. By cellular thermal shift assay (CETSA), we determined that MRL-494 stabilizes BamA and BamA E470K from thermally induced aggregation, indicating direct or proximal binding to both BamA and BamA E470K Thus, it is the altered activity of BamA E470K responsible for resistance to MRL-494. Strikingly, MRL-494 possesses a second mechanism of action that kills gram-positive organisms. In microbes lacking an OM, MRL-494 lethally disrupts the cytoplasmic membrane. We suggest that the compound cannot disrupt the cytoplasmic membrane of gram-negative bacteria because it cannot penetrate the OM. Instead, MRL-494 inhibits OMP biogenesis from outside the OM by targeting BamA. The identification of a small molecule that inhibits OMP biogenesis at the cell surface represents a distinct class of antibacterial agents.
Competing Interests: Competing interest statement: X.H., F.P.R.-R., A.G.S., J.C.M., C.J.B., S.B., Q.S., H.W., M.F.H., R.E.P., A.K.O., T.A.B., D.M.R., and S.S.W. are employed by Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA and may be shareholders in Merck & Co., Inc., Kenilworth, NJ, USA. H.S. and T.R. are employed by Prokaryotics, Inc., and may be shareholders in Prokaryotics, Inc., Union, NJ, USA. T.J.S. received research funds under a grant from Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA.
Databáze: MEDLINE
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