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Modi G, Marqus GM, Vippila MR, Gollapalli DR, Kim Y, Manna AC, Chacko S, Maltseva N, Wang X, Cullinane RT, Zhang Y, Kotler JLM, Kuzmic P, Zhang M, Lawson AP, Joachimiak A, Cheung A, Snider BB, Rothstein DM, Cuny GD, Hedstrom L. The Enzymatic Activity of Inosine 5'-Monophosphate Dehydrogenase May Not Be a Vulnerable Target for Staphylococcus aureus Infections. ACS Infect Dis 2021; 7:3062-3076. [PMID: 34590817 DOI: 10.1021/acsinfecdis.1c00342] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Many bacterial pathogens, including Staphylococcus aureus, require inosine 5'-monophosphate dehydrogenase (IMPDH) for infection, making this enzyme a promising new target for antibiotics. Although potent selective inhibitors of bacterial IMPDHs have been reported, relatively few have displayed antibacterial activity. Here we use structure-informed design to obtain inhibitors of S. aureus IMPDH (SaIMPDH) that have potent antibacterial activity (minimal inhibitory concentrations less than 2 μM) and low cytotoxicity in mammalian cells. The physicochemical properties of the most active compounds were within typical Lipinski/Veber space, suggesting that polarity is not a general requirement for achieving antibacterial activity. Five compounds failed to display activity in mouse models of septicemia and abscess infection. Inhibitor-resistant S. aureus strains readily emerged in vitro. Resistance resulted from substitutions in the cofactor/inhibitor binding site of SaIMPDH, confirming on-target antibacterial activity. These mutations decreased the binding of all inhibitors tested, but also decreased catalytic activity. Nonetheless, the resistant strains had comparable virulence to wild-type bacteria. Surprisingly, strains expressing catalytically inactive SaIMPDH displayed only a mild virulence defect. Collectively these observations question the vulnerability of the enzymatic activity of SaIMPDH as a target for the treatment of S. aureus infections, suggesting other functions of this protein may be responsible for its role in infection.
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Affiliation(s)
- Gyan Modi
- Department of Biology, Brandeis University, Waltham, Massachusetts 02453, United States
| | - Gary M. Marqus
- Graduate Program in Chemistry, Brandeis University, Waltham Massachusetts 02453, United States
| | - Mohana Rao Vippila
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Health Building 2, 4849 Calhoun Rd., Houston, Texas 77204, United States
| | | | - Youngchang Kim
- Center for Structural Genomics of Infectious Diseases, Consortium for Advanced Science and Engineering, University of Chicago, Chicago, Illinois 60667, United States
- The Structural Biology Center, X-ray Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Adhar C. Manna
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755, United States
| | - Shibin Chacko
- Department of Biology, Brandeis University, Waltham, Massachusetts 02453, United States
| | - Natalia Maltseva
- Center for Structural Genomics of Infectious Diseases, Consortium for Advanced Science and Engineering, University of Chicago, Chicago, Illinois 60667, United States
- The Structural Biology Center, X-ray Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Xingyou Wang
- Graduate Program in Chemistry, Brandeis University, Waltham Massachusetts 02453, United States
| | - Ryan T. Cullinane
- Department of Biochemistry, Brandeis University, Massachusetts 02453, United States
| | - Yubo Zhang
- Department of Biochemistry, Brandeis University, Massachusetts 02453, United States
| | - Judy L. M. Kotler
- Graduate Program in Biochemistry and Biophysics, Brandeis University, Waltham, Massachusetts 02453, United States
| | - Petr Kuzmic
- BioKin Ltd., Watertown, Massachusetts 02472, United States
| | - Minjia Zhang
- Department of Biology, Brandeis University, Waltham, Massachusetts 02453, United States
| | - Ann P. Lawson
- Department of Biology, Brandeis University, Waltham, Massachusetts 02453, United States
| | - Andrzej Joachimiak
- Center for Structural Genomics of Infectious Diseases, Consortium for Advanced Science and Engineering, University of Chicago, Chicago, Illinois 60667, United States
- The Structural Biology Center, X-ray Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois 60367, United States
| | - Ambrose Cheung
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755, United States
| | - Barry B. Snider
- Department of Chemistry, Brandeis University, Waltham, Massachusetts 02453, United States
| | - David M. Rothstein
- David Rothstein Consulting, LLC, Lexington, Massachusetts 02421, United States
| | - Gregory D. Cuny
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Health Building 2, 4849 Calhoun Rd., Houston, Texas 77204, United States
| | - Lizbeth Hedstrom
- Department of Biology, Brandeis University, Waltham, Massachusetts 02453, United States
- Department of Chemistry, Brandeis University, Waltham, Massachusetts 02453, United States
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