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Wu XR, Chen WY, Liu L, Yang KW. Discovery of hydroxamate as a promising scaffold dually inhibiting metallo- and serine-β-lactamases. Eur J Med Chem 2024; 265:116055. [PMID: 38134748 DOI: 10.1016/j.ejmech.2023.116055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 12/11/2023] [Accepted: 12/12/2023] [Indexed: 12/24/2023]
Abstract
The bacterial infection mediated by β-lactamases MβLs and SβLs has grown into an emergent health threat, however, development of a molecule that dual inhibits both MβLs and SβLs is challenging. In this work, a series of hydroxamates 1a-g, 2a-e, 3a-c, 4a-c were synthesized, characterized by 1H and 13C NMR and confirmed by HRMS. Biochemical assays revealed that these molecules dually inhibited MβLs (NDM-1, IMP-1) and SβLs (KPC-2, OXA-48), with an IC50 value in the range of 0.64-41.08 and 1.01-41.91 μM (except 1a and 1d on SβLs, IC50 > 50 μM), and 1f was found to be the best inhibitor with an IC50 value in the range of 0.64-1.32 and 0.57-1.01 μM, respectively. Mechanism evaluation indicated that 1f noncompetitively and irreversibly inhibited NDM-1 and KPC-2, with Ki value of 2.5 and 0.55 μM, is a time- and dose-dependent inhibitor of both MβLs and SβLs. MIC tests shown that all hydroxamates increased the antimicrobial effect of MER on E. coli-NDM-1 and E. coli-IMP-1 (expect 1b, 1d, 1g and 2d), resulting in a 2-8-fold reduction in MICs of MER, 1e-g, 2b-d, 3a-c and 4b-c decreased 2-4-fold MICs of MER on E. coli-KPC-2, and 1c, 1f-g, 2a-c, 3b, 4a and 4c decreased 2-16-fold MICs of MER on E. coli-OXA-48. Most importantly, 1f-g, 2b-c, 3b and 4c exhibited the dual synergizing inhibition against both E. coli-MβLs and E. coli-SβLs tested, resulting in a 2-8-fold reduction in MICs of MER, and 1f was found to have the best effect on the drug-resistant bacteria tested. Also, 1f shown synergizing antimicrobial effect on five clinical isolates EC04, EC06, EC08, EC10 and EC24 that produce NDM-1, resulting in a 2-8-fold reduction in MIC of MER, but its effect on E. coli and K. pneumonia-KPC-NDM was not to be observed using the same dose of inhibitor. Mice tests shown that the monotherapy of 1f or 4a in combination with MER significantly reduced the bacterial load of E. coli-NDM-1 and E. coli-OXA-48 cells in liver and spleen, respectively. The discovery in this work offered a promising bifunctional scaffold for creating the specific molecules that dually inhibit MβLs and MβLs, in combating antibiotic-resistant bacteria.
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Affiliation(s)
- Xiao-Rong Wu
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an, 710127, PR China
| | - Wei-Ya Chen
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an, 710127, PR China
| | - Lu Liu
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an, 710127, PR China
| | - Ke-Wu Yang
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an, 710127, PR China.
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Liu W, Wang J, Wang S, Yue K, Hu Y, Liu X, Wang L, Wan S, Xu X. Discovery of new non-covalent and covalent inhibitors targeting SARS-CoV-2 papain-like protease and main protease. Bioorg Chem 2023; 140:106830. [PMID: 37683544 DOI: 10.1016/j.bioorg.2023.106830] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 06/04/2023] [Accepted: 08/30/2023] [Indexed: 09/10/2023]
Abstract
Global coronavirus disease 2019 (COVID-19) pandemic still threatens human health and public safety, and the development of effective antiviral agent is urgently needed. The SARS-CoV-2 main protease (Mpro) and papain-like protease (PLpro) are vital proteins in viral replication and promising therapeutic targets. Additionally, PLpro also modulates host immune response by cleaving ubiquitin and interferon-stimulated gene product 15 (ISG15) from ISGylated host proteins. In this report, we identified [1,2]selenazolo[5,4-c]pyridin-3(2H)-one and benzo[d]isothiazol-3(2H)-one as attractive scaffolds of PLpro and Mpro inhibitors. The representative compounds 6c and 7e exhibited excellent PLpro inhibition with percent inhibition of 42.9% and 44.9% at 50 nM, respectively. The preliminary enzyme kinetics experiment and fluorescent labelling experiment results determined that 6c was identified as a covalent PLpro inhibitor, while 7e was a non-covalent inhibitor. Molecular docking and dynamics simulations revealed that 6c and 7e bound to Zn-finger domain of PLpro. Compounds 6c and 7e were also identified to potent Mpro inhibitors, and they exhibited potent antiviral activities in SARS-CoV-2 infected Vero E6 cells, with EC50 value of 3.9 μM and 7.4 μM, respectively. In addition, the rat liver homogenate half-life of 6c and 7e exceeded 24 h. These findings suggest that 6c and 7e are promising led compounds for further development of PLpro/Mpro dual-target antiviral drugs.
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Affiliation(s)
- Wandong Liu
- Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, 266003 Qingdao, China
| | - Juan Wang
- Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, 266003 Qingdao, China
| | - Suyun Wang
- Key Laboratory of Special Pathogens and Biosafety, Center for Biosafety Mega-Science, Wuhan Institute of Virology, Chinese Academy of Sciences, 430071 Wuhan, China
| | - Kairui Yue
- Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, 266003 Qingdao, China
| | - Yu Hu
- Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, 266003 Qingdao, China
| | - Xiaochun Liu
- Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, 266003 Qingdao, China
| | - Lihao Wang
- Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, 266003 Qingdao, China
| | - Shengbiao Wan
- Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, 266003 Qingdao, China.
| | - Ximing Xu
- Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, 266003 Qingdao, China.
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3
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Jia Y, Schroeder B, Pfeifer Y, Fröhlich C, Deng L, Arkona C, Kuropka B, Sticht J, Ataka K, Bergemann S, Wolber G, Nitsche C, Mielke M, Leiros HKS, Werner G, Rademann J. Kinetics, Thermodynamics, and Structural Effects of Quinoline-2-Carboxylates, Zinc-Binding Inhibitors of New Delhi Metallo-β-lactamase-1 Re-sensitizing Multidrug-Resistant Bacteria for Carbapenems. J Med Chem 2023; 66:11761-11791. [PMID: 37585683 DOI: 10.1021/acs.jmedchem.3c00171] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/18/2023]
Abstract
Carbapenem resistance mediated by metallo-β-lactamases (MBL) such as New Delhi metallo-β-lactamase-1 (NDM-1) has become a major factor threatening the efficacy of essential β-lactam antibiotics. Starting from hit fragment dipicolinic acid (DPA), 8-hydroxy- and 8-sulfonamido-quinoline-2-carboxylic acids were developed as inhibitors of NDM-1 with highly improved inhibitory activity and binding affinity. The most active compounds formed reversibly inactive ternary protein-inhibitor complexes with two zinc ions as proven by native protein mass spectrometry and bio-layer interferometry. Modification of the NDM-1 structure with remarkable entropic gain was shown by isothermal titration calorimetry and NMR spectroscopy of isotopically labeled protein. The best compounds were potent inhibitors of NDM-1 and other representative MBL with no or little inhibition of human zinc-binding enzymes. These inhibitors significantly reduced the minimum inhibitory concentrations (MIC) of meropenem for multidrug-resistant bacteria recombinantly expressing blaNDM-1 as well as for several multidrug-resistant clinical strains at concentrations non-toxic to human cells.
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Affiliation(s)
- Yuwen Jia
- Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Str. 2+4, Berlin 14195, Germany
| | - Barbara Schroeder
- Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Str. 2+4, Berlin 14195, Germany
| | - Yvonne Pfeifer
- FG13 Nosocomial Pathogens and Antibiotic Resistances, Department of Infectious Diseases, Robert Koch Institute, Burgstraße 37, Wernigerode 38855, Germany
| | - Christopher Fröhlich
- Department of Chemistry, Faculty of Science and Technology, UiT The Arctic University of Norway, Tromsø 9037, Norway
| | - Lihua Deng
- Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Str. 2+4, Berlin 14195, Germany
| | - Christoph Arkona
- Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Str. 2+4, Berlin 14195, Germany
| | - Benno Kuropka
- Core Facility BioSupraMol, Institute for Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, Berlin 14195, Germany
| | - Jana Sticht
- Core Facility BioSupraMol, Institute for Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, Berlin 14195, Germany
| | - Kenichi Ataka
- Department of Physics, Freie Universität Berlin, Arnimallee 14, Berlin 14195, Germany
| | - Silke Bergemann
- Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Str. 2+4, Berlin 14195, Germany
| | - Gerhard Wolber
- Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Str. 2+4, Berlin 14195, Germany
| | - Christoph Nitsche
- Research School of Chemistry, Australian National University, Canberra 2601, Australian Capital Territory, Australia
| | - Martin Mielke
- Department of Infectious Diseases, Robert Koch Institute, Nordufer 20, Berlin 13353, Germany
| | - Hanna-Kirsti S Leiros
- Department of Chemistry, Faculty of Science and Technology, UiT The Arctic University of Norway, Tromsø 9037, Norway
| | - Guido Werner
- FG13 Nosocomial Pathogens and Antibiotic Resistances, Department of Infectious Diseases, Robert Koch Institute, Burgstraße 37, Wernigerode 38855, Germany
| | - Jörg Rademann
- Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Str. 2+4, Berlin 14195, Germany
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4
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Antibacterial Activity of Ebselen. Int J Mol Sci 2023; 24:ijms24021610. [PMID: 36675123 PMCID: PMC9864093 DOI: 10.3390/ijms24021610] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 01/02/2023] [Accepted: 01/09/2023] [Indexed: 01/15/2023] Open
Abstract
Ebselen is a low-molecular-weight organoselenium compound that has been broadly studied for its antioxidant, anti-inflammatory, and cytoprotective properties. These advantageous properties were initially associated with mimicking the activity of selenoprotein glutathione peroxidase, but the biomedical impact of this compound appear to be far more complex. Ebselen serves as a substrate or inhibitor with multiple protein/enzyme targets, whereas inhibition typically originates from the covalent modification of cysteine residues by opening the benzisoselenazolone ring and S-Se bond formation. The inhibition of enzymes of various classes and origins has been associated with substantial antimicrobial potential among other activities. In this contribution, we summarize the current state of the art regarding the antibacterial activity of ebselen. This activity, alone and in combination with commercial pharmaceuticals, against pathogens, including those resistant to drugs, is presented, together with the molecular mechanism behind the reactivity. The specific inactivation of thioredoxin reductase, bacterial toxins, and other resistance factors is considered to have certain therapeutic implications. Synergistic action and sensitization to common antibiotics assisted with the use of ebselen appear to be promising directions in the treatment of persistent infections.
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Dihydroxyphenyl-substituted thiosemicarbazone: A potent scaffold for the development of metallo-β-lactamases inhibitors and antimicrobial. Bioorg Chem 2022; 127:105928. [PMID: 35717802 DOI: 10.1016/j.bioorg.2022.105928] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Revised: 05/21/2022] [Accepted: 06/01/2022] [Indexed: 11/23/2022]
Abstract
The superbug infection mediated by metallo-β-lactamases (MβLs) has grown into anemergent health threat, and development of MβL inhibitors is an ideal strategy to combat the infection. In this work, twenty-five thiosemicarbazones 1a-e, 2a-e, 3a-e, 4a-d, 5a-d and 6a-b were synthesized and assayed against MβLs ImiS, NDM-1 and L1. The gained molecules specifically inhibited NDM-1 and ImiS, exhibiting an IC50 value in the range of 0.37-21.35 and 0.45-8.76 µM, and 2a was found to be the best inhibitor, with an IC50 of 0.37 and 0.45 µM, respectively, using meropenem (MER) as substrate. Enzyme kinetics and dialysis tests revealed and confirmed by ITC that 2a is a time-and dose-dependent inhibitor of ImiS and NDM-1, it competitively and reversibly inhibited ImiS with a Ki value of 0.29 µM, but irreversibly inhibited NDM-1. Structure-activity relationship disclosed that the substitute dihydroxylbenzene significantly enhanced inhibitory activity of thiosemicarbazones on ImiS and NDM-1. Most importantly, 1a-e, 2a-e and 3a-b alone more strongly sterilized E. coli-ImiS and E. coli-NDM-1 than the MER, displaying a MIC value in the range of 8-128 μg/mL, and 2a was found to be the best reagent with a MIC of 8 and 32 μg/mL. Also, 2a alone strongly sterilized the clinical isolates EC01, EC06-EC08, EC24 and K. pneumonia-KPC-NDM, showing a MIC value in the range of 16-128 μg/mL, and exhibited synergistic inhibition with MER on these bacteria tested, resulting in 8-32-fold reduction in MIC of MER. SEM images shown that the bacteria E. coli-ImiS, E. coli-NDM-1, EC24, K. pneumonia-KPC and K. pneumonia-KPC-NDM treated with 2a (64 μg/mL) suffered from distortion, emerging adhesion between individual cells and crumpled membranes. Mice tests shown that monotherapy of 2a evidently limited growth of EC24 cells, and in combination with MER, it significantly reduced the bacterial load in liver and spleen. Docking studies suggest that the 2,4-dihydroxylbenzene of 2a acts as zinc-binding group with the Zn(II) and the residual amino acids in CphA active center, tightly anchoring the inhibitor at active site. This work offered a promising scaffold for the development of MβLs inhibitors, specifically the antimicrobial for clinically drug-resistant isolates.
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6
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Aromatic Schiff bases confer inhibitory efficacy against New Delhi metallo-β-lactamase-1 (NDM-1). Bioorg Chem 2022; 126:105910. [PMID: 35653899 DOI: 10.1016/j.bioorg.2022.105910] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 05/10/2022] [Accepted: 05/23/2022] [Indexed: 12/24/2022]
Abstract
The irregular use of antibiotics has created a natural selection pressure for bacteria to adapt resistance. Bacterial resistance caused by metallo-β-lactamases (MβLs) has been the most prevalent in terms of posing a threat to human health. The New Delhi metallo-β-lactamase-1 (NDM-1) has been shown to be capable of hydrolyzing almost all β-lactams. In this work, eight aromatic Schiff bases 1-8 were prepared and identified by enzyme kinetic assays to be the potent inhibitors of NDM-1 (except 4). These molecules exhibited a more than 95 % inhibition, and an IC50 value in the range of 0.13-19 μM on the target enzyme, and 3 was found to be the most effective inhibitor (IC50 = 130 nM). Analysis of structure-activity relationship revealed that the o-hydroxy phenyl improved the inhibitory activity of Schiff bases on NDM-1. The inhibition mode assays including isothermal titration calorimetry (ITC) disclosed that both compounds 3 and 5 exhibited a reversibly mixed inhibition on NDM-1, with a Ki value of 1.9 and 10.8 μM, respectively. Antibacterial activity tests indicated that a dose of 64 μg·mL-1 Schiff bases resulted in 2-128-fold reduction in MICs of cefazolin on E. coli producing NDM-1 (except 4). Cytotoxicity assays showed that both Schiff bases 3 and 5 have low cytotoxicity on the mouse fibroblast (L929) cells at a concentration of up to 400 μM. Docking studies suggested that the hydroxyl group interacts with Gln123 and Glu152 of NDM-1, and the amino groups interact with the backbone amide groups of Glu152 and Asp223. This study provided a novel scaffold for the development of NDM-1 inhibitors.
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7
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The development of New Delhi metallo-β-lactamase-1 inhibitors since 2018. Microbiol Res 2022; 261:127079. [DOI: 10.1016/j.micres.2022.127079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 04/22/2022] [Accepted: 05/23/2022] [Indexed: 11/21/2022]
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Emert-Sedlak LA, Moukha-Chafiq O, Shi H, Du S, Alvarado JJ, Pathak V, Tanner SG, Hunter RN, Nebane M, Chen L, Ilina TV, Ishima R, Zhang S, Kuzmichev YV, Wonderlich ER, Schader SM, Augelli-Szafran CE, Ptak RG, Smithgall TE. Inhibitors of HIV-1 Nef-Mediated Activation of the Myeloid Src-Family Kinase Hck Block HIV-1 Replication in Macrophages and Disrupt MHC-I Downregulation. ACS Infect Dis 2022; 8:91-105. [PMID: 34985256 PMCID: PMC9274903 DOI: 10.1021/acsinfecdis.1c00288] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
HIV-1 Nef is an attractive target for antiretroviral drug discovery because of its role in promoting HIV-1 infectivity, replication, and host immune system avoidance. Here, we applied a screening strategy in which recombinant HIV-1 Nef protein was coupled to activation of the Src-family tyrosine kinase Hck, which enhances the HIV-1 life cycle in macrophages. Nef stimulates recombinant Hck activity in vitro, providing a robust assay for chemical library screening. High-throughput screening of more than 730 000 compounds using the Nef·Hck assay identified six unique hit compounds that bound directly to recombinant Nef by surface plasmon resonance (SPR) in vitro and inhibited HIV-1 replication in primary macrophages in the 0.04 to 5 μM range without cytotoxicity. Eighty-four analogs were synthesized around an isothiazolone scaffold from this series, many of which bound to recombinant Nef and inhibited HIV-1 infectivity in the low to submicromolar range. Compounds in this series restored MHC-I to the surface of HIV-infected primary cells and disrupted a recombinant protein complex of Nef with the C-terminal tail of MHC-I and the μ1 subunit of the AP-1 endocytic trafficking protein. Nef inhibitors in this class have the potential to block HIV-1 replication in myeloid cells and trigger recognition of HIV-infected cells by the adaptive immune system in vivo.
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Affiliation(s)
- Lori A. Emert-Sedlak
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, 450 Technology Drive, Pittsburgh, PA 15219
| | - Omar Moukha-Chafiq
- Department of Chemistry, Southern Research Institute, 2000 Ninth Avenue South, Birmingham, AL 35205
| | - Haibin Shi
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, 450 Technology Drive, Pittsburgh, PA 15219
| | - Shoucheng Du
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, 450 Technology Drive, Pittsburgh, PA 15219
| | - John J. Alvarado
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, 450 Technology Drive, Pittsburgh, PA 15219
| | - Vibha Pathak
- Department of Chemistry, Southern Research Institute, 2000 Ninth Avenue South, Birmingham, AL 35205
| | - Samuel G. Tanner
- Department of Chemistry, Southern Research Institute, 2000 Ninth Avenue South, Birmingham, AL 35205
| | - Robert N. Hunter
- Department of Chemistry, Southern Research Institute, 2000 Ninth Avenue South, Birmingham, AL 35205
| | - Miranda Nebane
- Department of High-throughput Screening, Drug Discovery Division, Southern Research Institute, 2000 Ninth Avenue South, Birmingham, AL 35205
| | - Li Chen
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, 450 Technology Drive, Pittsburgh, PA 15219
| | - Tatiana V. Ilina
- Department of Structural Biology, University of Pittsburgh School of Medicine, 3501 Fifth Avenue, Pittsburgh, PA 15260
| | - Rieko Ishima
- Department of Structural Biology, University of Pittsburgh School of Medicine, 3501 Fifth Avenue, Pittsburgh, PA 15260
| | - Sixue Zhang
- Department of High-throughput Screening, Drug Discovery Division, Southern Research Institute, 2000 Ninth Avenue South, Birmingham, AL 35205
| | - Yury V. Kuzmichev
- Department of Infectious Disease Research, Drug Development Division, Southern Research Institute, 431 Aviation Way, Frederick, MD 21701
| | - Elizabeth R. Wonderlich
- Department of Infectious Disease Research, Drug Development Division, Southern Research Institute, 431 Aviation Way, Frederick, MD 21701
| | - Susan M. Schader
- Department of Infectious Disease Research, Drug Development Division, Southern Research Institute, 431 Aviation Way, Frederick, MD 21701
| | | | - Roger G. Ptak
- Department of Infectious Disease Research, Drug Development Division, Southern Research Institute, 431 Aviation Way, Frederick, MD 21701
| | - Thomas E. Smithgall
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, 450 Technology Drive, Pittsburgh, PA 15219
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Enzyme Inhibitors: The Best Strategy to Tackle Superbug NDM-1 and Its Variants. Int J Mol Sci 2021; 23:ijms23010197. [PMID: 35008622 PMCID: PMC8745225 DOI: 10.3390/ijms23010197] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Revised: 12/20/2021] [Accepted: 12/23/2021] [Indexed: 01/06/2023] Open
Abstract
Multidrug bacterial resistance endangers clinically effective antimicrobial therapy and continues to cause major public health problems, which have been upgraded to unprecedented levels in recent years, worldwide. β-Lactam antibiotics have become an important weapon to fight against pathogen infections due to their broad spectrum. Unfortunately, the emergence of antibiotic resistance genes (ARGs) has severely astricted the application of β-lactam antibiotics. Of these, New Delhi metallo-β-lactamase-1 (NDM-1) represents the most disturbing development due to its substrate promiscuity, the appearance of variants, and transferability. Given the clinical correlation of β-lactam antibiotics and NDM-1-mediated resistance, the discovery, and development of combination drugs, including NDM-1 inhibitors, for NDM-1 bacterial infections, seems particularly attractive and urgent. This review summarizes the research related to the development and optimization of effective NDM-1 inhibitors. The detailed generalization of crystal structure, enzyme activity center and catalytic mechanism, variants and global distribution, mechanism of action of existing inhibitors, and the development of scaffolds provides a reference for finding potential clinically effective NDM-1 inhibitors against drug-resistant bacteria.
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Nagulapalli Venkata KC, Ellebrecht M, Tripathi SK. Efforts towards the inhibitor design for New Delhi metallo-beta-lactamase (NDM-1). Eur J Med Chem 2021; 225:113747. [PMID: 34391033 DOI: 10.1016/j.ejmech.2021.113747] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 07/16/2021] [Accepted: 08/03/2021] [Indexed: 10/20/2022]
Abstract
Antimicrobial stewardship is imperative when treating bacterial infections because the misuse and overuse of antibiotics have caused pathogens to develop life-threatening resistance mechanisms. The New Delhi metallo-beta-lactamase (NDM-1) is one of many enzymes that enable bacterial resistance. NDM-1 is a more recently discovered beta-lactamase with the ability to inactivate a wide range of beta-lactam antibiotics. Multiple NDM-1 inhibitors have been designed and tested; however, due to the complexity of the NDM-1 active site, there is currently no inhibitor on the market. Consequently, an infection caused by bacteria possessing the gene for the NDM-1 enzyme is a serious and potentially fatal complication. An abundance of research has been invested over the past decade in search of an NDM-1 inhibitor. This review aims to summarize various NDM-1 inhibitor designs that have been developed in recent years.
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Affiliation(s)
| | - Morgan Ellebrecht
- St. Louis College of Pharmacy, University of Health Sciences and Pharmacy, St. Louis, MO, 63110, USA
| | - Siddharth K Tripathi
- National Center for Natural Products Research, School of Pharmacy, The University of Mississippi, University, MS, 38677, USA
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Bahr G, González LJ, Vila AJ. Metallo-β-lactamases in the Age of Multidrug Resistance: From Structure and Mechanism to Evolution, Dissemination, and Inhibitor Design. Chem Rev 2021; 121:7957-8094. [PMID: 34129337 PMCID: PMC9062786 DOI: 10.1021/acs.chemrev.1c00138] [Citation(s) in RCA: 96] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Antimicrobial resistance is one of the major problems in current practical medicine. The spread of genes coding for resistance determinants among bacteria challenges the use of approved antibiotics, narrowing the options for treatment. Resistance to carbapenems, last resort antibiotics, is a major concern. Metallo-β-lactamases (MBLs) hydrolyze carbapenems, penicillins, and cephalosporins, becoming central to this problem. These enzymes diverge with respect to serine-β-lactamases by exhibiting a different fold, active site, and catalytic features. Elucidating their catalytic mechanism has been a big challenge in the field that has limited the development of useful inhibitors. This review covers exhaustively the details of the active-site chemistries, the diversity of MBL alleles, the catalytic mechanism against different substrates, and how this information has helped developing inhibitors. We also discuss here different aspects critical to understand the success of MBLs in conferring resistance: the molecular determinants of their dissemination, their cell physiology, from the biogenesis to the processing involved in the transit to the periplasm, and the uptake of the Zn(II) ions upon metal starvation conditions, such as those encountered during an infection. In this regard, the chemical, biochemical and microbiological aspects provide an integrative view of the current knowledge of MBLs.
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Affiliation(s)
- Guillermo Bahr
- Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET, Universidad Nacional de Rosario, Ocampo y Esmeralda S/N, 2000 Rosario, Argentina
- Area Biofísica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000 Rosario, Argentina
| | - Lisandro J. González
- Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET, Universidad Nacional de Rosario, Ocampo y Esmeralda S/N, 2000 Rosario, Argentina
- Area Biofísica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000 Rosario, Argentina
| | - Alejandro J. Vila
- Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET, Universidad Nacional de Rosario, Ocampo y Esmeralda S/N, 2000 Rosario, Argentina
- Area Biofísica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000 Rosario, Argentina
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12
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Sun LY, Chen C, Su J, Li JQ, Jiang Z, Gao H, Chigan JZ, Ding HH, Zhai L, Yang KW. Ebsulfur and Ebselen as highly potent scaffolds for the development of potential SARS-CoV-2 antivirals. Bioorg Chem 2021; 112:104889. [PMID: 33915460 PMCID: PMC8026246 DOI: 10.1016/j.bioorg.2021.104889] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 03/31/2021] [Accepted: 04/01/2021] [Indexed: 01/25/2023]
Abstract
The emerging COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has raised a global catastrophe. To date, there is no specific antiviral drug available to combat this virus, except the vaccine. In this study, the main protease (Mpro) required for SARS-CoV-2 viral replication was expressed and purified. Thirty-six compounds were tested as inhibitors of SARS-CoV-2 Mpro by fluorescence resonance energy transfer (FRET) technique. The half-maximal inhibitory concentration (IC50) values of Ebselen and Ebsulfur analogs were obtained to be in the range of 0.074-0.91 μM. Notably, the molecules containing furane substituent displayed higher inhibition against Mpro, followed by Ebselen 1i (IC50 = 0.074 μM) and Ebsulfur 2k (IC50 = 0.11 μM). The action mechanism of 1i and 2k were characterized by enzyme kinetics, pre-incubation and jump dilution assays, as well as fluorescent labeling experiments, which suggested that both compounds covalently and irreversibly bind to Mpro, while molecular docking suggested that 2k formed an SS bond with the Cys145 at the enzymatic active site. This study provides two very potent scaffolds Ebsulfur and Ebselen for the development of covalent inhibitors of Mpro to combat COVID-19.
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Affiliation(s)
- Le-Yun Sun
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710127, PR China
| | - Cheng Chen
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710127, PR China
| | - Jianpeng Su
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710127, PR China
| | - Jia-Qi Li
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710127, PR China
| | - Zhihui Jiang
- Department of Pharmacy, General Hospital of Southern Theatre Command of PLA, Guangzhou 510010, PR China
| | - Han Gao
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710127, PR China
| | - Jia-Zhu Chigan
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710127, PR China
| | - Huan-Huan Ding
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710127, PR China
| | - Le Zhai
- Shaanxi Key Laboratory of Phytochemistry, College of Chemistry and Chemical Engineering, Baoji University of Arts and Sciences, Baoji 72101, Shaanxi Province, PR China
| | - Ke-Wu Yang
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710127, PR China.
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13
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Gao H, Li JQ, Kang PW, Chigan JZ, Wang H, Liu L, Xu YS, Zhai L, Yang KW. N-acylhydrazones confer inhibitory efficacy against New Delhi metallo-β-lactamase-1. Bioorg Chem 2021; 114:105138. [PMID: 34229201 DOI: 10.1016/j.bioorg.2021.105138] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 06/25/2021] [Accepted: 06/27/2021] [Indexed: 01/23/2023]
Abstract
The expression of β-lactamases, especially metallo-β-lactamases (MβLs) in bacteria is one of the main causes of drug resistance. In this work, an effective N-acylhydrazone scaffold as MβL inhibitor was constructed and characterized. The biological activity assays indicated that the synthesized N-acylhydrazones 1-11 preferentially inhibited MβL NDM-1, and 1 was found to be the most effective inhibitor with an IC50 of 1.2 µM. Analysis of IC50 data revealed a structure-activity relationship, which is that the pyridine and hydroxylbenzene substituents at 2-position improved inhibition of the compounds on NDM-1. ITC and enzyme kinetics assays suggested that it reversibly and competitively inhibited NDM-1 (Ki = 0.29 ± 0.05 µM). The synthesized N-acylhydrazones showed synergistic antibacterial activities with meropenem, reduced 4-16-fold MIC of meropenem on NDM-1- producing E. coli BL21 (DE3), while 1 restored 4-fold activity of meropenem on K. pneumonia expressing NDM-1 (NDM-K. pneumoniae). The mice experiments suggested that 1 combined meropenem to fight against NDM-K. pneumoniae infection in the spleen and liver. Cytotoxicity assays showed that 1 and 2 have low cytotoxicity. This study offered a new framework for the development of NDM-1 inhibitors.
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Affiliation(s)
- Han Gao
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710127, PR China
| | - Jia-Qi Li
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710127, PR China
| | - Peng-Wei Kang
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710127, PR China
| | - Jia-Zhu Chigan
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710127, PR China
| | - Huan Wang
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710127, PR China
| | - Lu Liu
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710127, PR China
| | - Yin-Sui Xu
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710127, PR China
| | - Le Zhai
- Shaanxi Key Laboratory of Phytochemistry, College of Chemistry and Chemical Engineering, Baoji University of Arts and Sciences, Baoji 72101, Shaanxi Province, PR China
| | - Ke-Wu Yang
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710127, PR China.
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14
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Jin WB, Xu C, Qi XL, Zeng P, Gao W, Lai KH, Chiou J, Chan EWC, Leung YC, Chan TH, Wong KY, Chen S, Chan KF. Synthesis of 1,3,4-trisubstituted pyrrolidines as meropenem adjuvants targeting New Delhi metallo-β-lactamase. NEW J CHEM 2021. [DOI: 10.1039/d0nj06090a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A promising NDM-1 inhibitor was discovered by the construction of pyrrolidine library via boric acid-catalyzed 1,3-dipolar cycloaddition and cell-based screens.
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15
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Structure-based design of covalent inhibitors targeting metallo-β-lactamases. Eur J Med Chem 2020; 203:112573. [DOI: 10.1016/j.ejmech.2020.112573] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 06/11/2020] [Accepted: 06/11/2020] [Indexed: 01/21/2023]
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16
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New Delhi metallo-β-lactamase-1 inhibitors for combating antibiotic drug resistance: recent developments. Med Chem Res 2020. [DOI: 10.1007/s00044-020-02580-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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17
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Metallo-β-Lactamase Inhibitors Inspired on Snapshots from the Catalytic Mechanism. Biomolecules 2020; 10:biom10060854. [PMID: 32503337 PMCID: PMC7356002 DOI: 10.3390/biom10060854] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 05/31/2020] [Accepted: 06/01/2020] [Indexed: 02/06/2023] Open
Abstract
β-Lactam antibiotics are the most widely prescribed antibacterial drugs due to their low toxicity and broad spectrum. Their action is counteracted by different resistance mechanisms developed by bacteria. Among them, the most common strategy is the expression of β-lactamases, enzymes that hydrolyze the amide bond present in all β-lactam compounds. There are several inhibitors against serine-β-lactamases (SBLs). Metallo-β-lactamases (MBLs) are Zn(II)-dependent enzymes able to hydrolyze most β-lactam antibiotics, and no clinically useful inhibitors against them have yet been approved. Despite their large structural diversity, MBLs have a common catalytic mechanism with similar reaction species. Here, we describe a number of MBL inhibitors that mimic different species formed during the hydrolysis process: substrate, transition state, intermediate, or product. Recent advances in the development of boron-based and thiol-based inhibitors are discussed in the light of the mechanism of MBLs. We also discuss the use of chelators as a possible strategy, since Zn(II) ions are essential for substrate binding and catalysis.
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Jin WB, Xu C, Cheung Q, Gao W, Zeng P, Liu J, Chan EWC, Leung YC, Chan TH, Wong KY, Chen S, Chan KF. Bioisosteric investigation of ebselen: Synthesis and in vitro characterization of 1,2-benzisothiazol-3(2H)-one derivatives as potent New Delhi metallo-β-lactamase inhibitors. Bioorg Chem 2020; 100:103873. [PMID: 32361294 DOI: 10.1016/j.bioorg.2020.103873] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Revised: 04/07/2020] [Accepted: 04/21/2020] [Indexed: 01/10/2023]
Abstract
Carbapenem-resistant Enterobacteriaceae (CRE) producing New Delhi metallo-β-lactamase (NDM-1) cause untreatable bacterial infections, posing a significant threat to human health. In the present study, by employing the concept of bioisosteric replacement of the selenium moiety of ebselen, we have designed, synthesized and characterized a small compound library of 2-substituted 1,2-benzisothiazol-3(2H)-one derivatives and related compounds for evaluating their cytotoxicity and synergistic activity in combination with meropenem against the E. coli Tg1 (NDM-1) strain. The most promising compound 3a demonstrated potent synergistic activity against a panel of clinically isolated NDM-1 positive CRE strains with FICI as low as 0.09. Moreover, its IC50 value and inhibition mechanism were also confirmed by using the enzyme inhibition assay and the ESI-MS analysis respectively. Importantly, compound 3a has acceptable toxicity and is not a PAINS. Because of its structural simplicity and potent synergistic activity in combination with meropenem, we propose that compound 3a may be a promising meropenem adjuvant and a new series of such compounds may worth further investigations.
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Affiliation(s)
- Wen Bin Jin
- State Key Laboratory of Chemical Biology and Drug Discovery and Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region; Faculty of Chinese Materia Medica, Yunnan University of Chinese Medicine, Kunming, Yunnan, China
| | - Chen Xu
- State Key Laboratory of Chemical Biology and Drug Discovery and Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region; Shenzhen Key Laboratory for Food Biological Safety Control, Food Safety and Technology Research Centre, The Hong Kong PolyU Shenzhen Research Institute, Shenzhen, China
| | - Qipeng Cheung
- State Key Laboratory of Chemical Biology and Drug Discovery and Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region; Shenzhen Key Laboratory for Food Biological Safety Control, Food Safety and Technology Research Centre, The Hong Kong PolyU Shenzhen Research Institute, Shenzhen, China
| | - Wei Gao
- State Key Laboratory of Chemical Biology and Drug Discovery and Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region
| | - Ping Zeng
- State Key Laboratory of Chemical Biology and Drug Discovery and Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region
| | - Jun Liu
- State Key Laboratory of Chemical Biology and Drug Discovery and Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region
| | - Edward W C Chan
- State Key Laboratory of Chemical Biology and Drug Discovery and Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region
| | - Yun-Chung Leung
- State Key Laboratory of Chemical Biology and Drug Discovery and Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region
| | - Tak Hang Chan
- State Key Laboratory of Chemical Biology and Drug Discovery and Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region; Department of Chemistry, McGill University, Montreal, Quebec H3A 2K6, Canada
| | - Kwok-Yin Wong
- State Key Laboratory of Chemical Biology and Drug Discovery and Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region
| | - Sheng Chen
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong Special Administrative Region.
| | - Kin-Fai Chan
- State Key Laboratory of Chemical Biology and Drug Discovery and Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region.
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Thomas PW, Cammarata M, Brodbelt JS, Monzingo AF, Pratt RF, Fast W. A Lysine-Targeted Affinity Label for Serine-β-Lactamase Also Covalently Modifies New Delhi Metallo-β-lactamase-1 (NDM-1). Biochemistry 2019; 58:2834-2843. [PMID: 31145588 DOI: 10.1021/acs.biochem.9b00393] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The divergent sequences, protein structures, and catalytic mechanisms of serine- and metallo-β-lactamases hamper the development of wide-spectrum β-lactamase inhibitors that can block both types of enzymes. The O-aryloxycarbonyl hydroxamate inactivators of Enterobacter cloacae P99 class C serine-β-lactamase are unusual covalent inhibitors in that they target both active-site Ser and Lys residues, resulting in a cross-link consisting of only two atoms. Many clinically relevant metallo-β-lactamases have an analogous active-site Lys residue used to bind β-lactam substrates, suggesting a common site to target with covalent inhibitors. Here, we demonstrate that an O-aryloxycarbonyl hydroxamate inactivator of serine-β-lactamases can also serve as a classical affinity label for New Delhi metallo-β-lactamase-1 (NDM-1). Rapid dilution assays, site-directed mutagenesis, and global kinetic fitting are used to map covalent modification at Lys211 and determine KI (140 μM) and kinact (0.045 min-1) values. Mass spectrometry of the intact protein and the use of ultraviolet photodissociation for extensive fragmentation confirm stoichiometric covalent labeling that occurs specifically at Lys211. A 2.0 Å resolution X-ray crystal structure of inactivated NDM-1 reveals that the covalent adduct is bound at the substrate-binding site but is not directly coordinated to the active-site zinc cluster. These results indicate that Lys-targeted affinity labels might be a successful strategy for developing compounds that can inactivate both serine- and metallo-β-lactamases.
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Affiliation(s)
| | | | | | | | - R F Pratt
- Department of Chemistry , Wesleyan University , Middletown , Connecticut 06459 , United States
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