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Chilamakuru NB, Vn AD, G VB, Pallaprolu N, Dande A, Nair D, Pemmadi RV, Reddy Y P, Peraman R. New synergistic benzoquinone scaffolds as inhibitors of mycobacterial cytochrome bc1 complex to treat multi-drug resistant tuberculosis. Eur J Med Chem 2024; 272:116479. [PMID: 38733886 DOI: 10.1016/j.ejmech.2024.116479] [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: 03/18/2024] [Revised: 04/25/2024] [Accepted: 05/04/2024] [Indexed: 05/13/2024]
Abstract
Through a comprehensive molecular docking study, a unique series of naphthoquinones clubbed azetidinone scaffolds was arrived with promising binding affinity to Mycobacterial Cytbc1 complex, a drug target chosen to kill multi-drug resistant Mycobacterium tuberculosis (MDR-Mtb). Five compounds from series-2, 2a, 2c, 2g, 2h, and 2j, showcased significant in vitro anti-tubercular activities against Mtb H37Rv and MDR clinical isolates. Further, synergistic studies of these compounds in combination with INH and RIF revealed a potent bactericidal effect of compound 2a at concentration of 0.39 μg/mL, and remaining (2c, 2g, 2h, and 2j) at 0.78 μg/mL. Exploration into the mechanism study through chemo-stress assay and proteome profiling uncovered the down-regulation of key proteins of electron-transport chain and Cytbc1 inhibition pathway. Metabolomics corroborated these proteome findings, and heightened further understanding of the underlying mechanism. Notably, in vitro and in vivo animal toxicity studies demonstrated minimal toxicity, thus underscoring the potential of these compounds as promising anti-TB agents in combination with RIF and INH. These active compounds adhered to Lipinski's Rule of Five, indicating the suitability of these compounds for drug development. Particular significance of molecules NQ02, 2a, and 2h, which have been patented (Published 202141033473).
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Affiliation(s)
- Naresh Babu Chilamakuru
- Research Scholar, Manipal Academy of Higher Education, Manipal, 576104, Karnataka, India; RERDS-CPR, Raghavendra Institute of Pharmaceutical Education and Research Campus, Ananthapuramu, 515721, Andhra Pradesh, India
| | - Azger Dusthackeer Vn
- ICMR-National Institute for Research in Tuberculosis (NIRT), Chennai, 600031, Tamil Nadu, India
| | - Varadaraj Bhat G
- Department of Pharmaceutical Chemistry, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India
| | - Nikhil Pallaprolu
- Department of Pharmaceutical Analysis, National Institute of Pharmaceutical Education and Research (NIPER), Hajipur 844102, Bihar, India
| | - Aishwarya Dande
- Department of Pharmaceutical Analysis, National Institute of Pharmaceutical Education and Research (NIPER), Hajipur 844102, Bihar, India
| | - Dina Nair
- ICMR-National Institute for Research in Tuberculosis (NIRT), Chennai, 600031, Tamil Nadu, India
| | - Raghuveer Varma Pemmadi
- RERDS-CPR, Raghavendra Institute of Pharmaceutical Education and Research Campus, Ananthapuramu, 515721, Andhra Pradesh, India; Department of Pharmaceutical Chemistry, A.K.R.G College of Pharmacy, Nallajerla, Andhra Pradesh 534112.
| | - Padmanabha Reddy Y
- RERDS-CPR, Raghavendra Institute of Pharmaceutical Education and Research Campus, Ananthapuramu, 515721, Andhra Pradesh, India
| | - Ramalingam Peraman
- RERDS-CPR, Raghavendra Institute of Pharmaceutical Education and Research Campus, Ananthapuramu, 515721, Andhra Pradesh, India; Department of Pharmaceutical Analysis, National Institute of Pharmaceutical Education and Research (NIPER), Hajipur 844102, Bihar, India.
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2
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Esser L, Xia D. Mitochondrial Cytochrome bc1 Complex as Validated Drug Target: A Structural Perspective. Trop Med Infect Dis 2024; 9:39. [PMID: 38393128 PMCID: PMC10892539 DOI: 10.3390/tropicalmed9020039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 01/19/2024] [Accepted: 01/24/2024] [Indexed: 02/25/2024] Open
Abstract
Mitochondrial respiratory chain Complex III, also known as cytochrome bc1 complex or cyt bc1, is a validated target not only for antibiotics but also for pesticides and anti-parasitic drugs. Although significant progress has been made in understanding the mechanisms of cyt bc1 function and inhibition by using various natural and synthetic compounds, important issues remain in overcoming drug resistance in agriculture and in evading cytotoxicity in medicine. In this review, we look at these issues from a structural perspective. After a brief description of the essential and common structural features, we point out the differences among various cyt bc1 complexes of different organisms, whose structures have been determined to atomic resolution. We use a few examples of cyt bc1 structures determined via bound inhibitors to illustrate both conformational changes observed and implications to the Q-cycle mechanism of cyt bc1 function. These structures not only offer views of atomic interactions between cyt bc1 complexes and inhibitors, but they also provide explanations for drug resistance when structural details are coupled to sequence changes. Examples are provided for exploiting structural differences in evolutionarily conserved enzymes to develop antifungal drugs for selectivity enhancement, which offer a unique perspective on differential interactions that can be exploited to overcome cytotoxicity in treating human infections.
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Affiliation(s)
| | - Di Xia
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, 37 Convent Drive, Room 2122C, Bethesda, MD 20892, USA
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3
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Zhang Y, Go EB, Perlatti B, Wu L, Bills GF, Ohashi M, Tang Y. Biosynthesis of AS2077715 and Funiculosin: Pathway Reconstitution and Identification of Enzymes that Form the All- cis Cyclopentanetetraol Moiety. J Am Chem Soc 2023; 145:6643-6647. [PMID: 36920241 PMCID: PMC10868378 DOI: 10.1021/jacs.3c01681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
The complete biosynthetic pathways of the potent antifungals AS2077715 (1) and funiculosin (2) are reconstituted and characterized. A five-enzyme cascade, including a multifunctional flavin-dependent monooxygenease and a repurposed O-methyltransferase, is involved to perform the dearomatization, stereoselective ring contraction, and redox transformations to morph a hydroxyphenyl-containing precursor into the unusual all-cis cyclopentanetetraol moiety.
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Affiliation(s)
- Yalong Zhang
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, California 90095, United States
| | - Eun Bin Go
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Bruno Perlatti
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
- Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center at Houston, Houston, Texas 77054, United States
| | - Lin Wu
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, California 90095, United States
| | - Gerald F. Bills
- Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center at Houston, Houston, Texas 77054, United States
| | - Masao Ohashi
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, California 90095, United States
| | - Yi Tang
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, California 90095, United States
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
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4
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Mamada SS, Nainu F, Masyita A, Frediansyah A, Utami RN, Salampe M, Emran TB, Lima CMG, Chopra H, Simal-Gandara J. Marine Macrolides to Tackle Antimicrobial Resistance of Mycobacterium tuberculosis. Mar Drugs 2022; 20:691. [PMID: 36355013 PMCID: PMC9697125 DOI: 10.3390/md20110691] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 10/26/2022] [Accepted: 10/27/2022] [Indexed: 09/01/2023] Open
Abstract
Tuberculosis has become a major health problem globally. This is worsened by the emergence of resistant strains of Mycobacterium tuberculosis showing ability to evade the effectiveness of the current antimycobacterial therapies. Therefore, the efforts carried out to explore new entities from many sources, including marine, are critical. This review summarizes several marine-derived macrolides that show promising activity against M. tuberculosis. We also provide information regarding the biosynthetic processes of marine macrolides, including the challenges that are usually experienced in this process. As most of the studies reporting the antimycobacterial activities of the listed marine macrolides are based on in vitro studies, the future direction should consider expanding the trials to in vivo and clinical trials. In addition, in silico studies should also be explored for a quick screening on marine macrolides with potent activities against mycobacterial infection. To sum up, macrolides derived from marine organisms might become therapeutical options for tackling antimycobacterial resistance of M. tuberculosis.
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Affiliation(s)
- Sukamto S. Mamada
- Department of Pharmacy, Faculty of Pharmacy, Hasanuddin University, Makassar 90245, Indonesia
| | - Firzan Nainu
- Department of Pharmacy, Faculty of Pharmacy, Hasanuddin University, Makassar 90245, Indonesia
| | - Ayu Masyita
- Department of Pharmaceutical Science and Technology, Faculty of Pharmacy, Hasanuddin University, Makassar 90245, Indonesia
- Research Center for Vaccine and Drugs, Research Organization for Health, National Research and Innovation Agency (BRIN), Tangerang Selatan 15318, Indonesia
| | - Andri Frediansyah
- Research Center for Food Technology and Processing, National Research and Innovation Agency (BRIN), Yogyakarta 55861, Indonesia
| | - Rifka Nurul Utami
- Department of Pharmaceutical Science and Technology, Faculty of Pharmacy, Hasanuddin University, Makassar 90245, Indonesia
- Institute of Pharmaceutical Science, King’s College London, London SE1 9NH, UK
| | | | - Talha Bin Emran
- Department of Pharmacy, BGC Trust University Bangladesh, Chittagong 4381, Bangladesh
- Department of Pharmacy, Faculty of Allied Health Sciences, Daffodil International University, Dhaka 1207, Bangladesh
| | | | - Hitesh Chopra
- Chitkara College of Pharmacy, Chitkara University, Punjab, India
| | - Jesus Simal-Gandara
- Nutrition and Bromatology Group, Department of Analytical and Food Chemistry, Faculty of Food Science and Technology, University of Vigo, Ourense Campus, E32004 Ourense, Spain
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5
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Young DH, Meunier B, Wang NX. Interaction of picolinamide fungicide primary metabolites UK-2A and CAS-649 with the cytochrome bc 1 complex Qi site: mutation effects and modelling in Saccharomyces cerevisiae. PEST MANAGEMENT SCIENCE 2022; 78:2657-2666. [PMID: 35355395 DOI: 10.1002/ps.6893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 03/30/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND Fenpicoxamid and florylpicoxamid are picolinamide fungicides targeting the Qi site of the cytochrome bc1 complex, via their primary metabolites UK-2A and CAS-649, respectively. We explore binding interactions and resistance mechanisms for picolinamides, antimycin A and ilicicolin H in yeast by testing effects of cytochrome b amino acid changes on fungicide sensitivity and interpreting results using molecular docking. RESULTS Effects of amino acid changes on sensitivity to UK-2A and CAS-649 were similar, with highest resistance associated with exchanges involving G37 and substitutions N31K and L198F. These changes, as well as K228M, also affected antimycin A, while ilicicolin H was affected by changes at G37 and L198, as well as Q22E. N31 substitution patterns suggest that a lysine at position 31 introduces an electrostatic interaction with neighbouring D229, causing disruption of a key salt-bridge interaction with picolinamides. Changes involving G37 and L198 imply resistance primarily through steric interference. G37 changes also showed differences between CAS-649 and UK-2A or antimycin A with respect to branched versus unbranched amino acids. N31K and substitution of G37 by large amino acids reduced growth rate substantially while L198 substitutions showed little effect on growth. CONCLUSION Binding of UK-2A and CAS-649 at the Qi site involves similar interactions such that general cross-resistance between fenpicoxamid and florylpicoxamid is anticipated in target pathogens. Some resistance mutations reduced growth rate and could carry a fitness penalty in pathogens. However, certain changes involving G37 and L198 carry little or no growth penalty and may pose the greatest risk for resistance development in the field. © 2022 Society of Chemical Industry.
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Affiliation(s)
- David H Young
- Crop Protection Discovery and Development, Corteva Agriscience, Indianapolis, IN, USA
| | - Brigitte Meunier
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France
| | - Nick X Wang
- Crop Protection Discovery and Development, Corteva Agriscience, Indianapolis, IN, USA
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Sarewicz M, Pintscher S, Pietras R, Borek A, Bujnowicz Ł, Hanke G, Cramer WA, Finazzi G, Osyczka A. Catalytic Reactions and Energy Conservation in the Cytochrome bc1 and b6f Complexes of Energy-Transducing Membranes. Chem Rev 2021; 121:2020-2108. [PMID: 33464892 PMCID: PMC7908018 DOI: 10.1021/acs.chemrev.0c00712] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Indexed: 12/16/2022]
Abstract
This review focuses on key components of respiratory and photosynthetic energy-transduction systems: the cytochrome bc1 and b6f (Cytbc1/b6f) membranous multisubunit homodimeric complexes. These remarkable molecular machines catalyze electron transfer from membranous quinones to water-soluble electron carriers (such as cytochromes c or plastocyanin), coupling electron flow to proton translocation across the energy-transducing membrane and contributing to the generation of a transmembrane electrochemical potential gradient, which powers cellular metabolism in the majority of living organisms. Cytsbc1/b6f share many similarities but also have significant differences. While decades of research have provided extensive knowledge on these enzymes, several important aspects of their molecular mechanisms remain to be elucidated. We summarize a broad range of structural, mechanistic, and physiological aspects required for function of Cytbc1/b6f, combining textbook fundamentals with new intriguing concepts that have emerged from more recent studies. The discussion covers but is not limited to (i) mechanisms of energy-conserving bifurcation of electron pathway and energy-wasting superoxide generation at the quinol oxidation site, (ii) the mechanism by which semiquinone is stabilized at the quinone reduction site, (iii) interactions with substrates and specific inhibitors, (iv) intermonomer electron transfer and the role of a dimeric complex, and (v) higher levels of organization and regulation that involve Cytsbc1/b6f. In addressing these topics, we point out existing uncertainties and controversies, which, as suggested, will drive further research in this field.
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Affiliation(s)
- Marcin Sarewicz
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Sebastian Pintscher
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Rafał Pietras
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Arkadiusz Borek
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Łukasz Bujnowicz
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Guy Hanke
- School
of Biological and Chemical Sciences, Queen
Mary University of London, London E1 4NS, U.K.
| | - William A. Cramer
- Department
of Biological Sciences, Purdue University, West Lafayette, Indiana 47907 United States
| | - Giovanni Finazzi
- Laboratoire
de Physiologie Cellulaire et Végétale, Université Grenoble Alpes, Centre National Recherche Scientifique,
Commissariat Energie Atomique et Energies Alternatives, Institut National
Recherche l’agriculture, l’alimentation et l’environnement, 38054 Grenoble Cedex 9, France
| | - Artur Osyczka
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
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7
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Bahuguna A, Rawat S, Rawat DS. QcrB in Mycobacterium tuberculosis: The new drug target of antitubercular agents. Med Res Rev 2021; 41:2565-2581. [PMID: 33400275 DOI: 10.1002/med.21779] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 11/23/2020] [Accepted: 12/12/2020] [Indexed: 11/08/2022]
Abstract
Drug-resistance in mycobacterial infections is a major global health problem that leads to high mortality and socioeconomic pressure in developing countries around the world. From finding new targets to discovering novel chemical scaffolds, there is an urgent need for the development of better approaches for the cure of tuberculosis. Recently, energy metabolism in mycobacteria, particularly the oxidative phosphorylation pathway of cellular respiration, has emerged as a novel target pathway in drug discovery. New classes of antibacterials which target oxidative phosphorylation pathway either by interacting with a protein or any step in the pathway of oxidative phosphorylation can combat dormant mycobacterial infections leading to shortening of tuberculosis chemotherapy. Adenosine triphosphate synthase is one such recently discovered target of the newly approved antitubercular drug bedaquiline. Cytochrome bcc is another new target of the antitubercular drug candidate Q203, currently in phase II clinical trial. Research suggests that b subunit of cytochrome bcc, QcrB, is the target of Q203. The review article describes the structure, function, and importance of targeting QcrB throwing light on all chemical classes of QcrB inhibitors discovered to date. An understanding of the structure and function of validated targets and their inhibitors would enable the development of new chemical entities.
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Affiliation(s)
| | - Srishti Rawat
- Department of Chemistry, University of Delhi, Delhi, India
| | - Diwan S Rawat
- Department of Chemistry, University of Delhi, Delhi, India
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8
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Forrestall KL, Burley DE, Cash MK, Pottie IR, Darvesh S. 2-Pyridone natural products as inhibitors of SARS-CoV-2 main protease. Chem Biol Interact 2020; 335:109348. [PMID: 33278462 PMCID: PMC7710351 DOI: 10.1016/j.cbi.2020.109348] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 10/05/2020] [Accepted: 11/26/2020] [Indexed: 12/16/2022]
Abstract
The disease, COVID-19, is caused by the severe acute respiratory coronavirus 2 (SARS-CoV-2) for which there is currently no treatment. The SARS-CoV-2 main protease (Mpro) is an important enzyme for viral replication. Small molecules that inhibit this protease could lead to an effective COVID-19 treatment. The 2-pyridone scaffold was previously identified as a possible key pharmacophore to inhibit SARS-CoV-2 Mpro. A search for natural, antimicrobial products with the 2-pyridone moiety was undertaken herein, and their calculated potency as inhibitors of SARS-CoV-2 Mpro was investigated. Thirty-three natural products containing the 2-pyridone scaffold were identified from the literature. An in silico methodology using AutoDock was employed to predict the binding energies and inhibition constants (Ki values) for each 2-pyridone-containing compound with SARS-CoV-2 Mpro. This consisted of molecular optimization of the 2-pyridone compound, docking of the compound with a crystal structure of SARS-CoV-2 Mpro, and evaluation of the predicted interactions and ligand-enzyme conformations. All compounds investigated bound to the active site of SARS-CoV-2 Mpro, close to the catalytic dyad (His-41 and Cys-145). Thirteen molecules had predicted Ki values <1 μM. Glu-166 formed a key hydrogen bond in the majority of the predicted complexes, while Met-165 had some involvement in the complex binding as a close contact to the ligand. Prominent 2-pyridone compounds were further evaluated for their ADMET properties. This work has identified 2-pyridone natural products with calculated potent inhibitory activity against SARS-CoV-2 Mpro and with desirable drug-like properties, which may lead to the rapid discovery of a treatment for COVID-19. 2-pyridone-scaffold is an inhibitory pharmacophore for SARS-CoV-2 Mpro. Thirty-three natural, antimicrobial products identified with 2-pyridone moiety. All 2-pyridone natural products bind to active site of SARS-CoV-2 Mproin silico. Thirteen molecules found to have potent inhibitory activity against SARS-CoV-2 Mpro. Inhibition of SARS-CoV-2 by natural 2-pyridones may lead to treatment of COVID-19.
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Affiliation(s)
- Katrina L Forrestall
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada
| | - Darcy E Burley
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada
| | - Meghan K Cash
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada
| | - Ian R Pottie
- Department of Chemistry and Physics, Faculty of Arts and Science, Mount Saint Vincent University, Halifax, Nova Scotia, B3M 2J6, Canada; Department of Chemistry, Faculty of Science, Saint Mary's University, Halifax, Nova Scotia, B3H 3C3, Canada
| | - Sultan Darvesh
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada; Department of Chemistry and Physics, Faculty of Arts and Science, Mount Saint Vincent University, Halifax, Nova Scotia, B3M 2J6, Canada; Department of Medicine (Neurology), Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada.
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9
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Natural Compound-derived Cytochrome bc1 Complex Inhibitors as Antifungal Agents. Molecules 2020; 25:molecules25194582. [PMID: 33036496 PMCID: PMC7583968 DOI: 10.3390/molecules25194582] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 09/25/2020] [Accepted: 10/06/2020] [Indexed: 01/09/2023] Open
Abstract
The high incidence of fungal pathogens has become a global issue for crop protection. A promising strategy to control fungal plant infections is based on the use of nature-inspired compounds. The cytochrome bc1 complex is an essential component of the cellular respiratory chain and is one of the most important fungicidal targets. Natural products have played a crucial role in the discovery of cytochrome bc1 inhibitors, as proven by the development of strobilurins, one of the most important classes of crop-protection agents, over the past two decades. In this review, we summarize advances in the exploration of natural product scaffolds for the design and development of new bc1 complex inhibitors. Particular emphasis is given to molecular modeling-based approaches and structure-activity relationship (SAR) studies performed to improve the stability and increase the potency of natural precursors. The collected results highlight the versatility of natural compounds and provide an insight into the potential development of nature-inspired derivatives as antifungal agents.
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10
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Yu X, Zhu X, Zhou Y, Li Q, Hu Z, Li T, Tao J, Dou M, Zhang M, Shao Y, Sun R. Discovery of N-Aryl-pyridine-4-ones as Novel Potential Agrochemical Fungicides and Bactericides. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:13904-13913. [PMID: 31765135 DOI: 10.1021/acs.jafc.9b06296] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
A series of N-aryl-pyridine-4-one derivatives were designed and synthesized using maltol and antidesmone as lead compounds, and then their fungicidal/bactericidal activities and possible mechanism of action against Colletotrichum musae were explored. Most of these compounds exhibited significant fungicidal activity in vitro. Especially, compound 23 has more than 90% inhibitory activity against nine plant pathogenic fungi at 50 μg mL-1, which is superior to azoxystrobin. Moreover, an in vivo bioassay also demonstrated that compound 23 exhibited high-efficiency broad-spectrum antifungal activity and can effectively control postharvest diseases of mango. In addition, it was found that compounds 22 and 23 can also effectively control rice bacterial leaf blight in pot experiments, which was even more effective than zhongshengmycin. Preliminary mechanism studies revealed that compound 23 may cause cell membrane and mitochondria destruction. These findings indicate that compound 23 can be used to develop potential agrochemical fungicides and bactericides.
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Affiliation(s)
- Xiuqiang Yu
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education, College of Plant Protection , Hainan University , Haikou , Hainan 570228 , People's Republic of China
| | - Xinyue Zhu
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education, College of Plant Protection , Hainan University , Haikou , Hainan 570228 , People's Republic of China
| | - Yang Zhou
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education, College of Plant Protection , Hainan University , Haikou , Hainan 570228 , People's Republic of China
| | - Qinglin Li
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education, College of Plant Protection , Hainan University , Haikou , Hainan 570228 , People's Republic of China
| | - Zhan Hu
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education, College of Plant Protection , Hainan University , Haikou , Hainan 570228 , People's Republic of China
| | - Ting Li
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources , Haikou , Hainan 570228 , People's Republic of China
| | - Jun Tao
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources , Haikou , Hainan 570228 , People's Republic of China
| | - Menglan Dou
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education, College of Plant Protection , Hainan University , Haikou , Hainan 570228 , People's Republic of China
| | - Meng Zhang
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education, College of Plant Protection , Hainan University , Haikou , Hainan 570228 , People's Republic of China
| | - Yu Shao
- Danzhou Tobacco Company , Hainan Provincial Branch of China National Tobacco Corporation (CNTC) , Danzhou , Hainan 571700 , People's Republic of China
| | - Ranfeng Sun
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education, College of Plant Protection , Hainan University , Haikou , Hainan 570228 , People's Republic of China
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11
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Mounkoro P, Michel T, Benhachemi R, Surpateanu G, Iorga BI, Fisher N, Meunier B. Mitochondrial complex III Q i -site inhibitor resistance mutations found in laboratory selected mutants and field isolates. PEST MANAGEMENT SCIENCE 2019; 75:2107-2114. [PMID: 30426681 DOI: 10.1002/ps.5264] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 11/08/2018] [Accepted: 11/08/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND Complex III inhibitors targeting the Qi -site have been known for decades; some are used or being developed as antimicrobial compounds. Target site resistance mutations have been reported in laboratory-selected mutants and in field isolates. Here, we present a brief overview of mutations found in laboratory-selected resistant mutants. We also provide a study of mutations observed in field isolates of Plasmopara viticola, in particular the ametoctradin resistance substitution, S34L that we analysed in the yeast model. RESULTS A survey of laboratory mutants showed that resistance could be caused by a large number of substitutions in the Qi -site. Four residues seemed key in term of resistance: N31, G37, L198 and K228. Using yeast, we analysed the effect of the ametoctradin resistance substitution S34L reported in field isolates of P. viticola. We showed that S34L caused a high level of resistance combined with a loss of complex III activity and growth competence. CONCLUSION Use of single site Qi -site inhibitors is expected to result in the selection of resistant mutants. However, if the substitution is associated with a fitness penalty, as may be the case with S34L, resistance development might not be an insuperable obstacle, although careful monitoring is required. © 2018 Society of Chemical Industry.
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Affiliation(s)
- Pierre Mounkoro
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Thomas Michel
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Rafik Benhachemi
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Georgiana Surpateanu
- Institut de Chimie des Substances Naturelles, CNRS, UPR 2301, Université Paris-Saclay, Labex LERMIT, Gif-sur-Yvette, France
| | - Bogdan I Iorga
- Institut de Chimie des Substances Naturelles, CNRS, UPR 2301, Université Paris-Saclay, Labex LERMIT, Gif-sur-Yvette, France
| | - Nicholas Fisher
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan, USA
| | - Brigitte Meunier
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
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12
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The Novel Arylamidine T-2307 Selectively Disrupts Yeast Mitochondrial Function by Inhibiting Respiratory Chain Complexes. Antimicrob Agents Chemother 2019; 63:AAC.00374-19. [PMID: 31182539 PMCID: PMC6658782 DOI: 10.1128/aac.00374-19] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 06/03/2019] [Indexed: 12/13/2022] Open
Abstract
The novel arylamidine T-2307 exhibits broad-spectrum in vitro and in vivo antifungal activities against clinically significant pathogens. Previous studies have shown that T-2307 accumulates in yeast cells via a specific polyamine transporter and disrupts yeast mitochondrial membrane potential. Further, it has little effect on rat liver mitochondrial function. The novel arylamidine T-2307 exhibits broad-spectrum in vitro and in vivo antifungal activities against clinically significant pathogens. Previous studies have shown that T-2307 accumulates in yeast cells via a specific polyamine transporter and disrupts yeast mitochondrial membrane potential. Further, it has little effect on rat liver mitochondrial function. The mechanism by which T-2307 disrupts yeast mitochondrial function is poorly understood, and its elucidation may provide important information for developing novel antifungal agents. This study aimed to determine how T-2307 promotes yeast mitochondrial dysfunction and to investigate the selectivity of this mechanism between fungi and mammals. T-2307 inhibited the respiration of yeast whole cells and isolated yeast mitochondria in a dose-dependent manner. The similarity of the effects of T-2307 and respiratory chain inhibitors on mitochondrial respiration prompted us to investigate the effect of T-2307 on mitochondrial respiratory chain complexes. T-2307 particularly inhibited respiratory chain complexes III and IV not only in Saccharomyces cerevisiae but also in Candida albicans, indicating that T-2307 acts against pathogenic fungi in a manner similar to that of yeast. Conversely, T-2307 showed little effect on bovine respiratory chain complexes. Additionally, we demonstrated that the inhibition of respiratory chain complexes by T-2307 resulted in a decrease in the intracellular ATP levels in yeast cells. These results indicate that inhibition of respiratory chain complexes III and IV is a key factor for selective disruption of yeast mitochondrial function and antifungal activity.
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13
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Mitochondrial respirasome works as a single unit and the cross-talk between complexes I, III 2 and IV stimulates NADH dehydrogenase activity. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1860:618-627. [PMID: 31251900 DOI: 10.1016/j.bbabio.2019.06.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 06/20/2019] [Accepted: 06/22/2019] [Indexed: 11/20/2022]
Abstract
Ustilago maydis is an aerobic basidiomycete that depends on oxidative phosphorylation for its ATP supply, pointing to the mitochondrion as a key player in its energy metabolism. Mitochondrial respiratory complexes I, III2, and IV occur in supramolecular structures named respirasome. In this work, we characterized the subunit composition and the kinetics of NADH:Q oxidoreductase activity of the digitonine-solubilized respirasome (1600 kDa) and the free-complex I (990 kDa). In the presence of 2,6-dimethoxy-1,4-benzoquinone (DBQ) and cytochrome c, both the respirasome NADH:O2 and the NADH:DBQ oxidoreductase activities were inhibited by rotenone, antimycin A or cyanide. A value of 2.4 for the NADH oxidized/oxygen reduced ratio was determined for the respirasome activity, while ROS production was less than 0.001% of the oxygen consumption rate. Analysis of the NADH:DBQ oxidoreductase activity showed that respirasome was 3-times more active and showed higher affinity than free-complex I. The results suggest that the contacts between complexes I, III2 and IV in the respirasome increase the catalytic efficiency of complex I and regulate its activity to prevent ROS production.
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14
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Bown L, Srivastava SK, Piercey BM, McIsaac CK, Tahlan K. Mycobacterial Membrane Proteins QcrB and AtpE: Roles in Energetics, Antibiotic Targets, and Associated Mechanisms of Resistance. J Membr Biol 2017; 251:105-117. [DOI: 10.1007/s00232-017-9997-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 10/20/2017] [Indexed: 02/08/2023]
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15
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Lambooij JM, Hoogenkamp MA, Brandt BW, Janus MM, Krom BP. Fungal mitochondrial oxygen consumption induces the growth of strict anaerobic bacteria. Fungal Genet Biol 2017; 109:1-6. [PMID: 28989089 DOI: 10.1016/j.fgb.2017.10.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 09/28/2017] [Accepted: 10/01/2017] [Indexed: 11/28/2022]
Abstract
Fungi are commonly encountered as part of a healthy oral ecosystem. Candida albicans is the most often observed and investigated fungal species in the oral cavity. The role of fungi in the oral ecosystem has remained enigmatic for decades. Recently, it was shown that C. albicans, in vitro, influences the bacterial composition of young oral biofilms, indicating it possibly plays a role in increasing diversity in the oral ecosystem. C. albicans favored growth of strictly anaerobic species under aerobic culture conditions. In the present study, the role of mitochondrial respiration, as mechanism by which C. albicans modifies its environment, was investigated. Using oxygen sensors, a rapid depletion of dissolved oxygen (dO2) was observed. This decrease was not C. albicans specific as several non-albicans Candida species showed similar oxygen consumption. Heat inactivation as well as addition of the specific mitochondrial respiration inhibitor Antimycin A inhibited depletion of dO2. Using 16S rDNA sequencing, it is shown that mitochondrial activity, more than physical presence of C. albicans is responsible for inducing growth of strictly anaerobic oral bacteria in aerobic growth conditions. The described mechanism of dO2 depletion may be a general mechanism by which fungi modulate their direct environment.
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Affiliation(s)
- Joost M Lambooij
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Michel A Hoogenkamp
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Bernd W Brandt
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Marleen M Janus
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Bastiaan P Krom
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
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16
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Identification of a New Isoindole-2-yl Scaffold as a Qo and Qi Dual Inhibitor of Cytochrome bc 1 Complex: Virtual Screening, Synthesis, and Biochemical Assay. Interdiscip Sci 2017; 10:781-791. [PMID: 28921079 DOI: 10.1007/s12539-017-0241-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2016] [Revised: 05/13/2017] [Accepted: 05/22/2017] [Indexed: 10/18/2022]
Abstract
Respiratory chain ubiquinol-cytochrome (cyt) c oxidoreductase (cyt bc 1 or complex III) has been demonstrated as a promising target for numerous antibiotics and fungicide applications. In this study, a virtual screening of NCI diversity database was carried out in order to find novel Qo/Qi cyt bc 1 complex inhibitors. Structure-based virtual screening and molecular docking methodology were employed to further screen compounds with inhibition activity against cyt bc 1 complex after extensive reliability validation protocol with cross-docking method and identification of the best score functions. Subsequently, the application of rational filtering procedure over the target database resulted in the elucidation of a novel class of cyt bc 1 complex potent inhibitors with comparable binding energies and biological activities to those of the standard inhibitor, antimycin.
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17
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Menning KJ, Menon BB, Fox G, Scott KM. Dissolved inorganic carbon uptake in Thiomicrospira crunogena XCL-2 is Δp- and ATP-sensitive and enhances RubisCO-mediated carbon fixation. Arch Microbiol 2015; 198:149-59. [PMID: 26581415 DOI: 10.1007/s00203-015-1172-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Revised: 10/30/2015] [Accepted: 11/11/2015] [Indexed: 11/26/2022]
Abstract
The gammaproteobacterium Thiomicrospira crunogena XCL-2 is an aerobic sulfur-oxidizing hydrothermal vent chemolithoautotroph that has a CO2 concentrating mechanism (CCM), which generates intracellular dissolved inorganic carbon (DIC) concentrations much higher than extracellular, thereby providing substrate for carbon fixation at sufficient rate. This CCM presumably requires at least one active DIC transporter to generate the elevated intracellular concentrations of DIC measured in this organism. In this study, the half-saturation constant (K CO2) for purified carboxysomal RubisCO was measured (276 ± 18 µM) which was much greater than the K CO2 of whole cells (1.03 µM), highlighting the degree to which the CCM facilitates CO2 fixation under low CO2 conditions. To clarify the bioenergetics powering active DIC uptake, cells were incubated in the presence of inhibitors targeting ATP synthesis (DCCD) or proton potential (CCCP). Incubations with each of these inhibitors resulted in diminished intracellular ATP, DIC, and fixed carbon, despite an absence of an inhibitory effect on proton potential in the DCCD-incubated cells. Electron transport complexes NADH dehydrogenase and the bc 1 complex were found to be insensitive to DCCD, suggesting that ATP synthase was the primary target of DCCD. Given the correlation of DIC uptake to the intracellular ATP concentration, the ABC transporter genes were targeted by qRT-PCR, but were not upregulated under low-DIC conditions. As the T. crunogena genome does not include orthologs of any genes encoding known DIC uptake systems, these data suggest that a novel, yet to be identified, ATP- and proton potential-dependent DIC transporter is active in this bacterium. This transporter serves to facilitate growth by T. crunogena and other Thiomicrospiras in the many habitats where they are found.
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Affiliation(s)
- Kristy J Menning
- Department of Integrative Biology, University of South Florida, 4202 East Fowler Avenue, Tampa, FL, 33620, USA
| | - Balaraj B Menon
- Department of Chemistry and Biochemistry, The University of Southern Mississippi, Hattiesburg, MS, USA
- Schepens Eye Research Institute, Harvard Medical School, Boston, MA, USA
| | - Gordon Fox
- Department of Integrative Biology, University of South Florida, 4202 East Fowler Avenue, Tampa, FL, 33620, USA
| | - Kathleen M Scott
- Department of Integrative Biology, University of South Florida, 4202 East Fowler Avenue, Tampa, FL, 33620, USA.
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18
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Segref A, Kevei É, Pokrzywa W, Schmeisser K, Mansfeld J, Livnat-Levanon N, Ensenauer R, Glickman MH, Ristow M, Hoppe T. Pathogenesis of human mitochondrial diseases is modulated by reduced activity of the ubiquitin/proteasome system. Cell Metab 2014; 19:642-52. [PMID: 24703696 DOI: 10.1016/j.cmet.2014.01.016] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 11/29/2013] [Accepted: 01/22/2014] [Indexed: 11/18/2022]
Abstract
Mitochondria maintain cellular homeostasis by coordinating ATP synthesis with metabolic activity, redox signaling, and apoptosis. Excessive levels of mitochondria-derived reactive oxygen species (ROS) promote mitochondrial dysfunction, triggering numerous metabolic disorders. However, the molecular basis for the harmful effects of excessive ROS formation is largely unknown. Here, we identify a link between mitochondrial stress and ubiquitin-dependent proteolysis, which supports cellular surveillance both in Caenorhabditis elegans and humans. Worms defective in respiration with elevated ROS levels are limited in turnover of a GFP-based substrate protein, demonstrating that mitochondrial stress affects the ubiquitin/proteasome system (UPS). Intriguingly, we observed similar proteolytic defects for disease-causing IVD and COX1 mutations associated with mitochondrial failure in humans. Together, these results identify a conserved link between mitochondrial metabolism and ubiquitin-dependent proteostasis. Reduced UPS activity during pathological conditions might potentiate disease progression and thus provides a valuable target for therapeutic intervention.
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Affiliation(s)
- Alexandra Segref
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Zülpicher Strasse 47a, 50674 Cologne, Germany
| | - Éva Kevei
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Zülpicher Strasse 47a, 50674 Cologne, Germany
| | - Wojciech Pokrzywa
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Zülpicher Strasse 47a, 50674 Cologne, Germany
| | - Kathrin Schmeisser
- Department of Human Nutrition, Institute of Nutrition, University of Jena, 07743 Jena, Germany
| | - Johannes Mansfeld
- Department of Human Nutrition, Institute of Nutrition, University of Jena, 07743 Jena, Germany; Energy Metabolism Laboratory, ETH Zürich, Schwerzenbach/Zürich, CH 8603, Switzerland
| | - Nurit Livnat-Levanon
- Department of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Regina Ensenauer
- Research Center, Dr. von Hauner Children's Hospital, Ludwig-Maximilians-Universität München, 80337 Munich, Germany
| | - Michael H Glickman
- Department of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Michael Ristow
- Department of Human Nutrition, Institute of Nutrition, University of Jena, 07743 Jena, Germany; Energy Metabolism Laboratory, ETH Zürich, Schwerzenbach/Zürich, CH 8603, Switzerland
| | - Thorsten Hoppe
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Zülpicher Strasse 47a, 50674 Cologne, Germany.
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19
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Singh SB, Liu W, Li X, Chen T, Shafiee A, Dreikorn S, Hornak V, Meinz M, Onishi JC. Structure-activity relationship of cytochrome bc1 reductase inhibitor broad spectrum antifungal ilicicolin H. Bioorg Med Chem Lett 2013; 23:3018-22. [PMID: 23562597 DOI: 10.1016/j.bmcl.2013.03.023] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 03/06/2013] [Indexed: 12/01/2022]
Abstract
Ilicicolin H is a broad spectrum antifungal agent showing sub micro g/mL MICs against Candida spp., Aspergillus fumigatus and Cryptococcus spp. It is a potent inhibitor (C50 2-3ng/mL) of the mitochondrial cytochrome bc1 reductase with over 1000-fold selectivity against rat liver cytochrome bc1 reductase. Structure-activity relationship of semisynthetic derivatives by chemical modification of ilicicolin H and its 19-hydroxy derivative produced by biotransformation have been described. Basic 4'-esters and moderately polar N- and O-alkyl derivatives retained antifungal and the cytochrome bc1 reductase activities. 4',19-Diacetate and 19-cyclopropyl acetate retained antifungal and enzyme activity and selectivity with over 20-fold improvement of plasma protein binding.
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Affiliation(s)
- Sheo B Singh
- Departments of Medicinal Chemistry and Infectious Disease, Merck Research Laboratories, PO Box 2000, Rahway, NJ 07065, USA.
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20
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Singh SB, Liu W, Li X, Chen T, Shafiee A, Card D, Abruzzo G, Flattery A, Gill C, Thompson JR, Rosenbach M, Dreikorn S, Hornak V, Meinz M, Kurtz M, Kelly R, Onishi JC. Antifungal spectrum, in vivo efficacy, and structure-activity relationship of ilicicolin h. ACS Med Chem Lett 2012; 3:814-7. [PMID: 24900384 DOI: 10.1021/ml300173e] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Accepted: 08/30/2012] [Indexed: 11/29/2022] Open
Abstract
Ilicicolin H is a polyketide-nonribosomal peptide synthase (NRPS)-natural product isolated from Gliocadium roseum, which exhibits potent and broad spectrum antifungal activity, with sub-μg/mL MICs against Candida spp., Aspergillus fumigatus, and Cryptococcus spp. It showed a novel mode of action, potent inhibition (IC50 = 2-3 ng/mL) of the mitochondrial cytochrome bc1 reductase, and over 1000-fold selectivity relative to rat liver cytochrome bc1 reductase. Ilicicolin H exhibited in vivo efficacy in murine models of Candida albicans and Cryptococcus neoformans infections, but efficacy may have been limited by high plasma protein binding. Systematic structural modification of ilicicolin H was undertaken to understand the structural requirement for the antifungal activity. The details of the biological activity of ilicicolin H and structural modification of some of the key parts of the molecule and resulting activity of the derivatives are discussed. These data suggest that the β-keto group is critical for the antifungal activity.
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Affiliation(s)
- Sheo B. Singh
- Departments
Medicinal Chemistry and Infectious Diseases, Merck Research Laboratories, Rahway, New Jersey 07065,
United States
| | - Weiguo Liu
- Departments
Medicinal Chemistry and Infectious Diseases, Merck Research Laboratories, Rahway, New Jersey 07065,
United States
| | - Xiaohua Li
- Departments
Medicinal Chemistry and Infectious Diseases, Merck Research Laboratories, Rahway, New Jersey 07065,
United States
| | - Tom Chen
- Departments
Medicinal Chemistry and Infectious Diseases, Merck Research Laboratories, Rahway, New Jersey 07065,
United States
| | - Ali Shafiee
- Departments
Medicinal Chemistry and Infectious Diseases, Merck Research Laboratories, Rahway, New Jersey 07065,
United States
| | - Deborah Card
- Departments
Medicinal Chemistry and Infectious Diseases, Merck Research Laboratories, Rahway, New Jersey 07065,
United States
| | - George Abruzzo
- Departments
Medicinal Chemistry and Infectious Diseases, Merck Research Laboratories, Rahway, New Jersey 07065,
United States
| | - Amy Flattery
- Departments
Medicinal Chemistry and Infectious Diseases, Merck Research Laboratories, Rahway, New Jersey 07065,
United States
| | - Charles Gill
- Departments
Medicinal Chemistry and Infectious Diseases, Merck Research Laboratories, Rahway, New Jersey 07065,
United States
| | - John R. Thompson
- Departments
Medicinal Chemistry and Infectious Diseases, Merck Research Laboratories, Rahway, New Jersey 07065,
United States
| | - Mark Rosenbach
- Departments
Medicinal Chemistry and Infectious Diseases, Merck Research Laboratories, Rahway, New Jersey 07065,
United States
| | - Sarah Dreikorn
- Departments
Medicinal Chemistry and Infectious Diseases, Merck Research Laboratories, Rahway, New Jersey 07065,
United States
| | - Viktor Hornak
- Departments
Medicinal Chemistry and Infectious Diseases, Merck Research Laboratories, Rahway, New Jersey 07065,
United States
| | - Maria Meinz
- Departments
Medicinal Chemistry and Infectious Diseases, Merck Research Laboratories, Rahway, New Jersey 07065,
United States
| | - Myra Kurtz
- Departments
Medicinal Chemistry and Infectious Diseases, Merck Research Laboratories, Rahway, New Jersey 07065,
United States
| | - Rosemarie Kelly
- Departments
Medicinal Chemistry and Infectious Diseases, Merck Research Laboratories, Rahway, New Jersey 07065,
United States
| | - Janet C. Onishi
- Departments
Medicinal Chemistry and Infectious Diseases, Merck Research Laboratories, Rahway, New Jersey 07065,
United States
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21
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Khan FA, Campbell AJ, Hoyt B, Herdman C, Ku T, Thangavelu S, Gordon RK. Oxidative mechanisms for the biotransformation of 1-methyl-1,6-dihydropyridine-2-carbaldoxime to pralidoxime chloride. Life Sci 2011; 89:911-7. [PMID: 21989207 DOI: 10.1016/j.lfs.2011.09.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Revised: 08/02/2011] [Accepted: 09/13/2011] [Indexed: 01/02/2023]
Abstract
AIMS Due to pralidoxime chloride's (2-PAM) positive charge, it's penetration through the blood brain barrier (BBB) and reactivation of organophosphate (OP) inhibited central nervous system (CNS) acetylcholinesterase (AChE) is poor. The results of CNS inhibited AChE are seizures. Pro-2-PAM (1-methyl-1,6-dihydropyridine-2-carbaldoxime), a pro-drug of 2-PAM, due to higher hydrophobicity, penetrates the BBB better but must be oxidized to 2-PAM, the active form of the oxime to reactivate CNS AChE in order to abrogate seizures. In this study, we characterize the in vivo mechanism of pro-2-PAM oxidation. MAIN METHODS A high pressure liquid chromatography (HPLC) assay was developed to quantify the conversion of pro-2-PAM to 2-PAM. NADPH oxidase activity was measured by a photo-luminescence assay using lucigenin substrate. Upon analysis, the rate of NADPH induced oxidation suggested that an alternate mechanism may be involved. Therefore, various enzyme co-factors of oxidation-reduction enzyme systems were evaluated, including nicotinamide adenine dinucleotide (NAD), nicotinamide adenine dinucleotide phosphate (NADP), flavin adenine dinucleotide (FAD), riboflavin 5'-phosphate (FMN), and riboflavin. Next, a spectrophotometric assay was developed to measure the conversion of pro-2-PAM to 2-PAM in the presence of riboflavin. KEY FINDINGS In guinea pig brain homogenate, diphenyleneiodonium (DPI), a specific NADPH oxidase inhibitor, reduced pro-2-PAM to 2-PAM conversion to less than 25%. In contrast, riboflavin, FAD, and FMN rapidly oxidized all pro-2-PAM to 2-PAM in an in vitro assay. Riboflavin oxidized pro-2-PAM reactivated diisopropylfluorophosphate (DFP) inhibited AChE. SIGNIFICANCE The present study shows that pro-2-PAM was rapidly oxidized by riboflavin to 2-PAM, which reactivated organophosphate (OP)-inhibited AChE.
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Affiliation(s)
- Farhat A Khan
- Department of Regulated Laboratories, Division of Regulated Activities, Silver Spring, MD 20910, United States.
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22
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Chabrier-Roselló Y, Giesselman BR, De Jesús-Andino FJ, Foster TH, Mitra S, Haidaris CG. Inhibition of electron transport chain assembly and function promotes photodynamic killing of Candida. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2010; 99:117-25. [PMID: 20381373 DOI: 10.1016/j.jphotobiol.2010.03.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Revised: 03/16/2010] [Accepted: 03/17/2010] [Indexed: 01/05/2023]
Abstract
Respiratory deficiency increases the sensitivity of the pathogenic fungi Candida albicans and Candida glabrata to oxidative stress induced by photodynamic therapy (PDT) sensitized by the cationic porphyrin meso-tetra (N-methyl-4-pyridyl) porphine tetra tosylate (TMP-1363). Since disruption of electron transport chain (ETC) function increases intracellular levels of reactive oxygen species in yeast, we determined whether interference with ETC assembly or function increased sensitivity to TMP-1363-PDT in C. albicans, C. glabrata and the non-pathogenic yeast Saccharomyces cerevisiae. Metabolic inhibitor antimycin A and defined genetic mutants were used to identify ETC components that contribute to the sensitivity to PDT. Inhibition of cytochrome bc(1) (Complex III) with antimycin A increases mitochondrial levels of reactive oxygen species. PDT performed following pre-treatment with antimycin A reduced colony forming units (CFU) of C. albicans and C. glabrata by approximately two orders of magnitude relative to PDT alone. A S. cerevisiae mitochondrial glutaredoxin grx5 mutant, defective in assembly of Fe-S clusters critical for Complex III function, displayed increased sensitivity to PDT. Furthermore, C. glabrata and S.cerevisiae mutants in cytochrome c oxidase (Complex IV) synthesis and assembly were also significantly more sensitive to PDT. These included suv3, encoding an ATP-dependent RNA helicase critical for maturation of cytochrome c oxidase subunit transcripts, and pet117, encoding an essential cytochrome c oxidase assembly factor. Following PDT, the reduction in CFU of these mutants was one to two orders of magnitude greater than in their respective parental strains. The data demonstrate that selective inhibition of ETC Complexes III and IV significantly increases the sensitivity of C. albicans, C. glabrata and S. cerevisiae to PDT sensitized with TMP-1363.
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Affiliation(s)
- Yeissa Chabrier-Roselló
- Department of Microbiology and Immunology, University of Rochester Medical Center, Box 672, 601 Elmwood Ave., Rochester, NY 14642, USA
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23
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Ding MG, di Rago JP, Trumpower BL. Combining Inhibitor Resistance-conferring Mutations in Cytochrome b Creates Conditional Synthetic Lethality in Saccharomyces cerevisiae. J Biol Chem 2009; 284:8478-85. [PMID: 19179332 DOI: 10.1074/jbc.m809278200] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The mitochondrial cytochrome bc(1) complex is an essential respiratory enzyme in oxygen-utilizing eukaryotic cells. Its core subunit, cytochrome b, contains two sites, center P and center N, that participate in the electron transfer activity of the bc(1) complex and that can be blocked by specific inhibitors. In yeast, there are various point mutations that confer inhibitor resistance at center P or center N. However, there are no yeast strains in which the bc(1) complex is resistant to both center P and center N inhibitors. We attempted to create such strains by crossing yeast strains with inhibitor-resistant mutations at center P with yeast strains with inhibitor-resistant mutations at center N. Characterization of yeast colonies emerging from the cross revealed that there were multiple colonies resistant against either inhibitor alone but that the mutational changes were ineffective when combined and when the yeast were grown in the presence of both inhibitors. Inhibitor titrations of bc(1) complex activities in mitochondrial membranes from the various yeast mutants showed that a mutation that confers resistance to an inhibitor at center P, when combined with a mutation that confers resistance to an inhibitor at center N, eliminates or markedly decreases the resistance conferred by the center N mutation. These results indicate that there is a pathway for structural communication between the two active sites of cytochrome b and open new possibilities for the utilization of center N as a potential drug target.
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Affiliation(s)
- Martina G Ding
- Department of Biochemistry, Dartmouth Medical School, Hanover, New Hampshire 03755, USA
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24
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Covian R, Trumpower BL. Ilicicolin Inhibition and Binding at Center N of the Dimeric Cytochrome bc1 Complex Reveal Electron Transfer and Regulatory Interactions between Monomers. J Biol Chem 2009; 284:8614-20. [PMID: 19176478 DOI: 10.1074/jbc.m808914200] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have determined the kinetics of ilicicolin binding and dissociation at center N of the yeast bc(1) complex and its effect on the reduction of cytochrome b with center P blocked. The addition of ilicicolin to the oxidized complex resulted in a non-linear inhibition of the extent of cytochrome b reduction by quinol together with a shift of the reduced b(H) heme spectrum, indicating electron transfer between monomers. The possibility of a fast exchange of ilicicolin between center N sites was excluded in two ways. First, kinetic modeling showed that fast movement of an inhibitor between monomers would result in a linear inhibition of the extent of cytochrome b reduction through center N. Second, we determined a very slow dissociation rate for ilicicolin (k = 1.2 x 10(-3) s(-1)) as calculated from its displacement by antimycin. Ilicicolin binding to the reduced bc(1) complex occurred in a single phase (k(on) = 1.5-1.7 x 10(5) m(-1) s(-1)) except in the presence of stigmatellin, where a second slower binding phase comprising approximately 50% of the spectral change was observed. This second kinetic event was weakly dependent on ilicicolin concentration, which suggests that binding of ilicicolin to one center N in the dimer transmits a slow (k = 2-3 s(-1)) conformational change that allows binding of the inhibitor in the other monomer. These results, together with the evidence for intermonomeric electron transfer, provide further support for a dimeric model of regulatory interactions between center P and center N sites in the bc(1) complex.
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Affiliation(s)
- Raul Covian
- Department of Biochemistry, Dartmouth Medical School, Hanover, New Hampshire 03755, USA
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Yang S, Ma HW, Yu L, Yu CA. On the mechanism of quinol oxidation at the QP site in the cytochrome bc1 complex: studied using mutants lacking cytochrome bL or bH. J Biol Chem 2008; 283:28767-76. [PMID: 18713733 DOI: 10.1074/jbc.m803013200] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
To elucidate the mechanism of bifurcated oxidation of quinol in the cytochrome bc1 complex, Rhodobacter sphaeroides mutants, H198N and H111N, lacking heme bL and heme bH, respectively, were constructed and characterized. Purified mutant complexes have the same subunit composition as that of the wild-type complex, but have only 9-11% of the electron transfer activity, which is sensitive to stigmatellin or myxothiazol. The Em values for hemes bL and bH in the H111N and H198N complexes are -95 and -35 mV, respectively. The pseudo first-order reduction rate constants for hemes bL and bH in H111N and H198N, by ubiquiniol, are 16.3 and 12.4 s(-1), respectively. These indicate that the Qp site in the H111N mutant complex is similar to that in the wild-type complex. Pre-steady state reduction rates of heme c1 by these two mutant complexes decrease to a similar extent of their activity, suggesting that the decrease in electron transfer activity is due to impairment of movement of the head domain of reduced iron-sulfur protein, caused by disruption of electron transfer from heme bL to heme bH. Both mutant complexes produce as much superoxide as does antimycin A-treated wild-type complex. Ascorbate eliminates all superoxide generating activity in the intact or antimycin inhibited wild-type or mutant complexes.
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Affiliation(s)
- Shaoqing Yang
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, Oklahoma 74078, USA
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