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Ng MY, Song ZJ, Tan CH, Bassetto M, Hagen T. Structural investigations on the mitochondrial uncouplers niclosamide and FCCP. FEBS Open Bio 2024; 14:1057-1071. [PMID: 38750619 PMCID: PMC11216929 DOI: 10.1002/2211-5463.13817] [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: 06/15/2023] [Revised: 02/26/2024] [Accepted: 05/02/2024] [Indexed: 07/03/2024] Open
Abstract
There has been renewed interest in using mitochondrial uncoupler compounds such as niclosamide and carbonyl cyanide p-(trifluoromethoxy)phenylhydrazone (FCCP) for the treatment of obesity, hepatosteatosis and diseases where oxidative stress plays a role. However, both FCCP and niclosamide have undesirable effects that are not due to mitochondrial uncoupling, such as inhibition of mitochondrial oxygen consumption by FCCP and induction of DNA damage by niclosamide. Through structure-activity analysis, we identified FCCP analogues that do not inhibit mitochondrial oxygen consumption but still provided good, although less potent, uncoupling activity. We also characterized the functional role of the niclosamide 4'-nitro group, the phenolic hydroxy group and the anilide amino group in mediating uncoupling activity. Our structural investigations provide important information that will aid further drug development.
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Affiliation(s)
- Mei Ying Ng
- Department of Biochemistry, Yong Loo Lin School of MedicineNational University of SingaporeSingapore
- Present address:
Department of Cancer BiologyDana‐Farber Cancer InstituteBostonMAUSA
| | - Zhi Jian Song
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical SciencesNanyang Technological UniversitySingapore
| | - Choon Hong Tan
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical SciencesNanyang Technological UniversitySingapore
| | - Marcella Bassetto
- School of Pharmacy and Pharmaceutical Sciences, College of Biomedical and Life SciencesCardiff UniversityUK
| | - Thilo Hagen
- Department of Biochemistry, Yong Loo Lin School of MedicineNational University of SingaporeSingapore
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2
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Ng MY, Song ZJ, Venkatesan G, Rodriguez-Cuenca S, West JA, Yang S, Tan CH, Ho PCL, Griffin JL, Vidal-Puig A, Bassetto M, Hagen T. Conjugating uncoupler compounds with hydrophobic hydrocarbon chains to achieve adipose tissue selective drug accumulation. Sci Rep 2024; 14:4932. [PMID: 38418847 PMCID: PMC10901892 DOI: 10.1038/s41598-024-54466-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 02/13/2024] [Indexed: 03/02/2024] Open
Abstract
One potential approach for treating obesity is to increase energy expenditure in brown and white adipose tissue. Here we aimed to achieve this outcome by targeting mitochondrial uncoupler compounds selectively to adipose tissue, thus avoiding side effects from uncoupling in other tissues. Selective drug accumulation in adipose tissue has been observed with many lipophilic compounds and dyes. Hence, we explored the feasibility of conjugating uncoupler compounds with a lipophilic C8-hydrocarbon chain via an ether bond. We found that substituting the trifluoromethoxy group in the uncoupler FCCP with a C8-hydrocarbon chain resulted in potent uncoupling activity. Nonetheless, the compound did not elicit therapeutic effects in mice, likely as a consequence of metabolic instability resulting from rapid ether bond cleavage. A lipophilic analog of the uncoupler compound 2,6-dinitrophenol, in which a C8-hydrocarbon chain was conjugated via an ether bond in the para-position (2,6-dinitro-4-(octyloxy)phenol), exhibited increased uncoupling activity compared to the parent compound. However, in vivo pharmacokinetics studies suggested that 2,6-dinitro-4-(octyloxy)phenol was also metabolically unstable. In conclusion, conjugation of a hydrophobic hydrocarbon chain to uncoupler compounds resulted in sustained or improved uncoupling activity. However, an ether bond linkage led to metabolic instability, indicating the need to conjugate lipophilic groups via other chemical bonds.
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Affiliation(s)
- Mei Ying Ng
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Zhi Jian Song
- School of Physical and Mathematical Sciences, Division of Chemistry and Biological Chemistry, Nanyang Technological University, Singapore, Singapore
| | | | - Sergio Rodriguez-Cuenca
- Wellcome-MRC Institute of Metabolic Science and Medical Research Council Metabolic Diseases Unit, The University of Cambridge, Cambridge, UK
| | - James A West
- Department of Biochemistry, The University of Cambridge, Cambridge, UK
| | - Shili Yang
- Department of Pharmacy, Faculty of Science, National University of Singapore, Singapore, Singapore
| | - Choon Hong Tan
- School of Physical and Mathematical Sciences, Division of Chemistry and Biological Chemistry, Nanyang Technological University, Singapore, Singapore
| | - Paul Chi-Lui Ho
- Department of Pharmacy, Faculty of Science, National University of Singapore, Singapore, Singapore
- School of Pharmacy, Monash University Malaysia, 47500, Subang Jaya, Malaysia
| | - Julian L Griffin
- The Rowett Institute of Nutrition and Health, The University of Aberdeen, Aberdeen, UK
| | - Antonio Vidal-Puig
- Wellcome-MRC Institute of Metabolic Science and Medical Research Council Metabolic Diseases Unit, The University of Cambridge, Cambridge, UK
| | - Marcella Bassetto
- School of Pharmacy and Pharmaceutical Sciences, College of Biomedical and Life Sciences, Cardiff University, Cardiff, UK.
| | - Thilo Hagen
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
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3
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Mlejnek P. Direct Interaction between N-Acetylcysteine and Cytotoxic Electrophile—An Overlooked In Vitro Mechanism of Protection. Antioxidants (Basel) 2022; 11:antiox11081485. [PMID: 36009205 PMCID: PMC9405167 DOI: 10.3390/antiox11081485] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 07/18/2022] [Accepted: 07/21/2022] [Indexed: 02/01/2023] Open
Abstract
In laboratory experiments, many electrophilic cytotoxic agents induce cell death accompanied by reactive oxygen species (ROS) production and/or by glutathione (GSH) depletion. Not surprisingly, millimolar concentrations of N-acetylcysteine (NAC), which is used as a universal ROS scavenger and precursor of GSH biosynthesis, inhibit ROS production, restore GSH levels, and prevent cell death. The protective effect of NAC is generally used as corroborative evidence that cell death induced by a studied cytotoxic agent is mediated by an oxidative stress-related mechanism. However, any simple interpretation of the results of the protective effects of NAC may be misleading because it is unable to interact with superoxide (O2•−), the most important biologically relevant ROS, and is a very weak scavenger of H2O2. In addition, NAC is used in concentrations that are unnecessarily high to stimulate GSH synthesis. Unfortunately, the possibility that NAC as a nucleophile can directly interact with cytotoxic electrophiles to form non-cytotoxic NAC–electrophile adduct is rarely considered, although it is a well-known protective mechanism that is much more common than expected. Overall, apropos the possible mechanism of the cytoprotective effect of NAC in vitro, it is appropriate to investigate whether there is a direct interaction between NAC and the cytotoxic electrophile to form a non-cytotoxic NAC–electrophilic adduct(s).
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Affiliation(s)
- Petr Mlejnek
- Department of Anatomy, Faculty of Medicine and Dentistry, Palacky University Olomouc, Hnevotinska 3, 77515 Olomouc, Czech Republic
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Timblin GA, Tharp KM, Ford B, Winchester JM, Wang J, Zhu S, Khan RI, Louie SK, Iavarone AT, Ten Hoeve J, Nomura DK, Stahl A, Saijo K. Mitohormesis reprogrammes macrophage metabolism to enforce tolerance. Nat Metab 2021; 3:618-635. [PMID: 34031590 PMCID: PMC8162914 DOI: 10.1038/s42255-021-00392-w] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 04/15/2021] [Indexed: 02/03/2023]
Abstract
Macrophages generate mitochondrial reactive oxygen species and mitochondrial reactive electrophilic species as antimicrobials during Toll-like receptor (TLR)-dependent inflammatory responses. Whether mitochondrial stress caused by these molecules impacts macrophage function is unknown. Here, we demonstrate that both pharmacologically driven and lipopolysaccharide (LPS)-driven mitochondrial stress in macrophages triggers a stress response called mitohormesis. LPS-driven mitohormetic stress adaptations occur as macrophages transition from an LPS-responsive to LPS-tolerant state wherein stimulus-induced pro-inflammatory gene transcription is impaired, suggesting tolerance is a product of mitohormesis. Indeed, like LPS, hydroxyoestrogen-triggered mitohormesis suppresses mitochondrial oxidative metabolism and acetyl-CoA production needed for histone acetylation and pro-inflammatory gene transcription, and is sufficient to enforce an LPS-tolerant state. Thus, mitochondrial reactive oxygen species and mitochondrial reactive electrophilic species are TLR-dependent signalling molecules that trigger mitohormesis as a negative feedback mechanism to restrain inflammation via tolerance. Moreover, bypassing TLR signalling and pharmacologically triggering mitohormesis represents a new anti-inflammatory strategy that co-opts this stress response to impair epigenetic support of pro-inflammatory gene transcription by mitochondria.
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Affiliation(s)
- Greg A Timblin
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA.
- Center for Bioengineering and Tissue Regeneration, Department of Surgery, University of California, San Francisco, San Francisco, CA, USA.
| | - Kevin M Tharp
- Center for Bioengineering and Tissue Regeneration, Department of Surgery, University of California, San Francisco, San Francisco, CA, USA
| | - Breanna Ford
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, Berkeley, CA, USA
- Novartis-Berkeley Center for Proteomics and Chemistry Technologies and Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA
| | - Janet M Winchester
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Jerome Wang
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Stella Zhu
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Rida I Khan
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Shannon K Louie
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Anthony T Iavarone
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, Berkeley, CA, USA
- QB3/Chemistry Mass Spectrometry Facility, University of California, Berkeley, Berkeley, CA, USA
| | - Johanna Ten Hoeve
- Department of Molecular and Medical Pharmacology, Crump Institute for Molecular Imaging and UCLA Metabolomics Center, University of California, Los Angeles, Los Angeles, CA, USA
| | - Daniel K Nomura
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, Berkeley, CA, USA
- Novartis-Berkeley Center for Proteomics and Chemistry Technologies and Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA
| | - Andreas Stahl
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, Berkeley, CA, USA
| | - Kaoru Saijo
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA.
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, USA.
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Khailova LS, Firsov AM, Kotova EA, Antonenko YN. Interaction of Potent Mitochondrial Uncouplers with Thiol-Containing Antioxidants. Antioxidants (Basel) 2019; 8:antiox8060194. [PMID: 31234606 PMCID: PMC6616877 DOI: 10.3390/antiox8060194] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 06/20/2019] [Accepted: 06/21/2019] [Indexed: 11/16/2022] Open
Abstract
It is generally considered that reactive oxygen species (ROS) are involved in the development of numerous pathologies. The level of ROS can be altered via the uncoupling of oxidative phosphorylation by using protonophores causing mitochondrial membrane depolarization. Here, we report that the uncoupling activity of potent protonophores, such as carbonyl cyanide 4-(trifluoromethoxy)phenylhydrazone (FCCP), carbonyl cyanide 3-chlorophenylhydrazone (CCCP), and fluazinam, can be abrogated by the addition of thiol-containing antioxidants to isolated mitochondria. In particular, N-acetylcysteine, glutathione, cysteine, and dithiothreitol removed both a decrease in the mitochondrial membrane potential and an increase in the respiration rate that is caused by FCCP. The thiols also reduced the electrical current that is induced by FCCP and CCCP across planar bilayer lipid membranes. Thus, when speculating on the mechanistic roles of ROS level modulation by mitochondrial uncoupling based on the antioxidant reversing certain FCCP and CCCP effects on cellular processes, one should take into account the ability of these protonophoric uncouplers to directly interact with the thiol-containing antioxidants.
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Affiliation(s)
- Ljudmila S Khailova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia.
| | - Alexander M Firsov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia.
| | - Elena A Kotova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia.
| | - Yuri N Antonenko
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia.
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6
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Kane MS, Paris A, Codron P, Cassereau J, Procaccio V, Lenaers G, Reynier P, Chevrollier A. Current mechanistic insights into the CCCP-induced cell survival response. Biochem Pharmacol 2017; 148:100-110. [PMID: 29277693 DOI: 10.1016/j.bcp.2017.12.018] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 12/20/2017] [Indexed: 01/13/2023]
Abstract
The ring-substituted derivatives of carbonyl cyanide phenylhydrazone, CCCP and FCCP, are routinely used for the analysis of the mitochondrial function in living cells, tissues, and isolated mitochondrial preparations. CCCP and FCCP are now being increasingly used for investigating the mechanisms of autophagy by inducing mitochondrial degradation through the disruption of the mitochondrial membrane potential (ΔΨm). Sustained perturbation of ΔΨm, which is normally tightly controlled to ensure cell proliferation and survival, triggers various stress pathways as part of the cellular adaptive response, the main components of which are mitophagy and autophagy. We here review current mechanistic insights into the induction of mitophagy and autophagy by CCCP and FCCP. In particular, we analyze the cellular modifications produced by the activation of two major pathways involving the signaling of the nuclear factor erythroid 2-related factor 2 (Nrf2) and the transcription factor EB (TFEB), and discuss the contribution of these pathways to the integrated cellular stress response.
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Affiliation(s)
- Mariame Selma Kane
- MitoLab, Mitochondrial Medicine Research Centre, UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, 49933 Angers, France
| | - Aurelien Paris
- MitoLab, Mitochondrial Medicine Research Centre, UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, 49933 Angers, France
| | - Philippe Codron
- MitoLab, Mitochondrial Medicine Research Centre, UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, 49933 Angers, France
| | - Julien Cassereau
- MitoLab, Mitochondrial Medicine Research Centre, UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, 49933 Angers, France
| | - Vincent Procaccio
- MitoLab, Mitochondrial Medicine Research Centre, UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, 49933 Angers, France
| | - Guy Lenaers
- MitoLab, Mitochondrial Medicine Research Centre, UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, 49933 Angers, France
| | - Pascal Reynier
- MitoLab, Mitochondrial Medicine Research Centre, UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, 49933 Angers, France
| | - Arnaud Chevrollier
- MitoLab, Mitochondrial Medicine Research Centre, UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, 49933 Angers, France.
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7
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Antonenko YN, Denisov SS, Silachev DN, Khailova LS, Jankauskas SS, Rokitskaya TI, Danilina TI, Kotova EA, Korshunova GA, Plotnikov EY, Zorov DB. A long-linker conjugate of fluorescein and triphenylphosphonium as mitochondria-targeted uncoupler and fluorescent neuro- and nephroprotector. Biochim Biophys Acta Gen Subj 2016; 1860:2463-2473. [PMID: 27450891 DOI: 10.1016/j.bbagen.2016.07.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 06/16/2016] [Accepted: 07/16/2016] [Indexed: 01/05/2023]
Abstract
BACKGROUND Limited uncoupling of oxidative phosphorylation is known to be beneficial in various laboratory models of diseases. Linking a triphenyl-phosphonium cation to fluorescein through a decyl (C10) spacer yields a fluorescent uncoupler, coined mitoFluo, that selectively accumulates in energized mitochondria (Denisov et al., Chem.Commun. 2014). METHODS Proton-transport activity of mitoFluo was tested in liposomes reconstituted with bacteriorhodopsin. To examine the uncoupling action on mitochondria, we monitored mitochondrial membrane potential in parallel with oxygen consumption. Neuro- and nephroprotecting activity was detected by a limb-placing test and a kidney ischemia/reperfusion protocol, respectively. RESULTS We compared mitoFluo properties with those of its newly synthesized analog having a short (butyl) spacer (C4-mitoFluo). MitoFluo, but not C4-mitoFluo, caused collapse of mitochondrial membrane potential resulting in stimulation of mitochondrial respiration. The dramatic difference in the uncoupling activity of mitoFluo and C4-mitoFluo was in line with the difference in their protonophoric activity on a lipid membrane. The accumulation of mitoFluo in mitochondria was more pronounced than that of C4-mitoFluo. MitoFluo decreased the rate of ROS production in mitochondria. MitoFluo was effective in preventing consequences of brain trauma in rats: it suppressed trauma-induced brain swelling and reduced a neurological deficit. Besides, mitoFluo attenuated acute kidney injury after ischemia/reperfusion in rats. CONCLUSIONS A long alkyl linker was proved mandatory for mitoFluo to be a mitochondria- targeted uncoupler. MitoFluo showed high protective efficacy in certain models of oxidative stress-related diseases. GENERAL SIGNIFICANCE MitoFluo is a candidate for developing therapeutic and fluorescence imaging agents to treat brain and kidney pathologies.
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Affiliation(s)
- Yuri N Antonenko
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119991, Russia.
| | - Stepan S Denisov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119991, Russia; Faculty of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Denis N Silachev
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Ljudmila S Khailova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Stanislovas S Jankauskas
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Tatyana I Rokitskaya
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Tatyana I Danilina
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Elena A Kotova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Galina A Korshunova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Egor Y Plotnikov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Dmitry B Zorov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119991, Russia
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8
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Mlejnek P, Dolezel P. Loss of mitochondrial transmembrane potential and glutathione depletion are not sufficient to account for induction of apoptosis by carbonyl cyanide 4-(trifluoromethoxy)phenylhydrazone in human leukemia K562 cells. Chem Biol Interact 2015; 239:100-10. [DOI: 10.1016/j.cbi.2015.06.033] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Revised: 06/07/2015] [Accepted: 06/22/2015] [Indexed: 12/20/2022]
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Dufour V, Stahl M, Baysse C. The antibacterial properties of isothiocyanates. MICROBIOLOGY-SGM 2014; 161:229-243. [PMID: 25378563 DOI: 10.1099/mic.0.082362-0] [Citation(s) in RCA: 146] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Isothiocyanates (ITCs) are natural plant products generated by the enzymic hydrolysis of glucosinolates found in Brassicaceae vegetables. These natural sulfur compounds and their dithiocarbamate conjugates have been previously evaluated for their anti-cancerous properties. Their antimicrobial properties have been previously studied as well, mainly for food preservation and plant pathogen control. Recently, several revelations concerning the mode of action of ITCs in prokaryotes have emerged. This review addresses these new studies and proposes a model to summarize the current knowledge and hypotheses for the antibacterial effect of ITCs and whether they may provide the basis for the design of novel antibiotics.
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Affiliation(s)
- Virginie Dufour
- Equipe EA1254, Microbiologie Risques Infectieux, University of Rennes 1, F-35042 Rennes cedex, France
| | - Martin Stahl
- Division of Gastroenterology, BC's Children's Hospital, Child and Family Research Institute and University of British Columbia, Vancouver, BC, Canada
| | - Christine Baysse
- Equipe EA1254, Microbiologie Risques Infectieux, University of Rennes 1, F-35042 Rennes cedex, France
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Schwöbel JAH, Koleva YK, Enoch SJ, Bajot F, Hewitt M, Madden JC, Roberts DW, Schultz TW, Cronin MTD. Measurement and Estimation of Electrophilic Reactivity for Predictive Toxicology. Chem Rev 2011; 111:2562-96. [DOI: 10.1021/cr100098n] [Citation(s) in RCA: 149] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Johannes A. H. Schwöbel
- School of Pharmacy and Chemistry, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, England
| | - Yana K. Koleva
- School of Pharmacy and Chemistry, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, England
| | - Steven J. Enoch
- School of Pharmacy and Chemistry, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, England
| | - Fania Bajot
- School of Pharmacy and Chemistry, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, England
| | - Mark Hewitt
- School of Pharmacy and Chemistry, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, England
| | - Judith C. Madden
- School of Pharmacy and Chemistry, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, England
| | - David W. Roberts
- School of Pharmacy and Chemistry, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, England
| | - Terry W. Schultz
- College of Veterinary Medicine, Department of Comparative Medicine, The University of Tennessee, 2407 River Drive, Knoxville, Tennessee 37996-4543, United States
| | - Mark T. D. Cronin
- School of Pharmacy and Chemistry, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, England
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Laski J, Jóźwiak Z. Induction of Thermotolerance by Chemical Agents in Enucleate Erythrocytes. Int J Radiat Biol 2009; 62:353-8. [PMID: 1356137 DOI: 10.1080/09553009214552201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Erythrocytes treated with various chemical agents for 1 h at 37 degrees C showed resistance to a subsequent 1 h heat treatment at 53 degrees C. Maximal thermotolerance was observed 6 h after 3 mM DNP and 0.03 mM disulfiram treatment and 4 h after diamide exposure at 0.3 mM. Our results suggest that chemically induced thermotolerance to heat treatment in erythrocytes was similar to heat-induced thermotolerance.
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Affiliation(s)
- J Laski
- Chair of Biophysics, University of Lódź, Poland
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12
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Kucera I. Inhibition by phenylglyoxal of nitrate transport in Paracoccus denitrificans: a comparison with the effect of a protonophorous uncoupler. Arch Biochem Biophys 2003; 409:327-34. [PMID: 12504899 DOI: 10.1016/s0003-9861(02)00550-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The amino acid modifier phenylglyoxal (PG) gradually inactivated the methyl viologen-coupled nitrate reductase activity of the anoxically grown whole cells of Paracoccus denitrificans. A double log plot of the pseudo-first-order inactivation rate constant versus PG concentration was linear with a mean slope of 1.4 (0.1M sodium phosphate) or 0.87 (0.1M sodium borate). Phenylglyoxalation of cells lowered the limiting velocity (V), while hardly affecting the apparent half-saturation concentration (K(m)) of nitrate. Nitrate afforded no protection against inactivation. The inhibition by PG could be removed by the detergent Triton X-100 or by the lipid-soluble tetraphenylphosphonium countercation, suggesting that PG exerts its effect at the level of nitrate transport. Based on studies with membrane potential- and pH-sensitive fluorescent probes, the inhibition was shown not to be due to changes in the electrochemical gradient of hydrogen ions. Both K(m) and V values for nitrate uptake increased in a hyperbolic fashion in response to exogenously added nitrite. Nitrite promoted a bypass of the inhibition caused by low concentrations of the proton-conducting agent carbonyl cyanide m-chlorophenylhydrazone (CCCP), but was almost ineffective in the case of the PG block. These results are rationalized in terms of two nitrate import pathways that are comparably inhibited by PG and differ in their sensitivities to CCCP. A simplified kinetic model for phenylglyoxalation is proposed to account for the observed nonintegral reaction orders.
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Affiliation(s)
- Igor Kucera
- Department of Biochemistry, Faculty of Science, Masaryk University, Kotlárská 2, CZ-61137, Brno, Czech Republic.
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13
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Podhradský D, Paulíková H, Toth G, Miko M. Effect of N-tricyanovinylamines on the level of glutathione in hepatocytes. DRUG METABOLISM AND DRUG INTERACTIONS 2002; 11:111-26. [PMID: 12369595 DOI: 10.1515/dmdi.1994.11.2.111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The effects of N-substituted tricyanovinylamines (N-TCVA; RNHC(CN)=C(CN)2) have been studied on rat hepatocytes and liver mitochondria. Derivatives of N-TCVA act on oxidative phosphorylation as uncouplers, and react with thiols within pH 5.0-8.5. N-Isobutyl-, N-benzyl-, and N-cyclohexyl-TCVA influence the level of GSH and GSSG in isolated hepatocytes. They can act as oxidants, but the level of GSSG increases (about 40%) only if the concentration of N-TCVA is higher than 1 micromol/l. If N-TCVA is added to a final concentration higher than 50 micromol/l a decrease of GSH and GSSG level is observed. Derivatives of N-TCVA also influence the level of GSH and GSSG in mitochondria. At 40-400 micromol/l N-TCVA in the incubation medium the level of GSSG increased and the ratio GSH/GSSG was influenced, but the level of total SH groups did not decrease.
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Affiliation(s)
- D Podhradský
- Department of Biochemistry, Faculty of Science P.J. Safárik University, Kosice, Slovakia
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Bijlsma S, Boelens HF, Hoefsloot HC, Smilde AK. Estimating reaction rate constants: comparison between traditional curve fitting and curve resolution. Anal Chim Acta 2000. [DOI: 10.1016/s0003-2670(00)00994-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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15
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Abstract
Mitochondria have long been recognized as the generators of energy for the cell. Like any other power source, however, mitochondria are highly vulnerable to inhibition or uncoupling of the energy harnessing process and run a high risk for catastrophic damage to the cell. The exquisite structural and functional characteristics of mitochondria provide a number of primary targets for xenobiotic-induced bioenergetic failure. They also provide opportunities for selective delivery of drugs to the mitochondrion. In light of the large number of natural, commercial, pharmaceutical, and environmental chemicals that manifest their toxicity by interfering with mitochondrial bioenergetics, it is important to understand the underlying mechanisms. The significance is further underscored by the recent identification of bioenergetic control points for cell replication and differentiation and the realization that mitochondria play a determinant role in cell signaling and apoptotic modes of cell death.
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Affiliation(s)
- K B Wallace
- Department of Biochemistry and Molecular Biology, University of Minnesota School of Medicine, Duluth 55812, USA.
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16
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Campo ML, Tedeschi H, Muro C, Kinnally KW. Effects of carbonyl cyanide phenylhydrazones on two mitochondrial ion channel activities. J Bioenerg Biomembr 1997; 29:223-31. [PMID: 9298707 DOI: 10.1023/a:1022453809357] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The respiratory uncouplers carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP) and carbonyl cyanide m-chlorophenylhydrazone (CCCP) affect the activities of two mitochondrial ion channels from mouse liver. At micromolar concentrations, the phenylhydrazones block the voltage-dependent 100-pS channel, mCS, and induce the multiple-conductance-level channel, MCC. The binding site(s) involved in perturbation of channel activities are probably distinct from the sites involved in uncoupling of oxidative phosphorylation which occurs at nanomolar concentrations of the phenylhydrazones. The effects of FCCP and CCCP on the mitochondrial ion channels could be partially reversed by washing with fresh media and were always reversed by perfusion with dithiothreitol. These results indicate that the effects of the phenylhydrazones on mitochondrial ion channels may be related to the ability of these compounds to act as sulfhydryl reagents and not to their protonophoric and uncoupling activity.
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Affiliation(s)
- M L Campo
- Departamento de Bioquímica y Biologia Molecular y Genética, Universidad de Extremadura, Cáceres, Spain
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17
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Abstract
The formation of the glutathione S-conjugate of monochlorobimane (GSH-bimane) in human colon adenocarcinoma cells was identified by HPLC-fluorimetry and its transport from the cells was found to be temperature-sensitive, saturable and ATP-dependent. The apparent K(m) and Vmax values were 2.4 +/- 0.5 nmol GSH-bimane/10(6) cells and 0.5 +/- 0.1 nmol GSH-bimane/min per 10(6) cells, respectively. This active transport of GSH-bimane was inhibited by low micromolar concentrations of classical uncouplers of oxidative phosphorylation, namely carbonylcyanide p-trifluoromethoxyphenylhydrazone (FCCP), carbonylcyanide m-chlorophenylhydrazone (CCCP) and 2,4-dinitrophenol (DNP). The efflux of GSH-bimane was competitively inhibited by chlorambucil (CMB) and 1-chloro-2,4-dinitrobenzene (CDNB), two other substrates of GST. This study demonstrates the presence and kinetic measurements of the glutathione S-conjugate export (GS-X) pump in human colon cancer cells, an export pump whose function has been implicated in the phenomenon of multidrug resistance.
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Affiliation(s)
- K Zhang
- Department of Biochemistry, Faculty of Medicine, National University of Singapore, Kent Ridge, Singapore
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18
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Kucera I. Oscillations of nitric oxide concentration in the perturbed denitrification pathway of Paracoccus denitrificans. Biochem J 1992; 286 ( Pt 1):111-6. [PMID: 1325776 PMCID: PMC1133025 DOI: 10.1042/bj2860111] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The metabolism of nitric oxide in Paracoccus denitrificans has been studied using a Clark-type electrode. The uncoupler carbonyl cyanide m-chlorophenylhydrazone (CCCP) and the SH reagent N-ethylmaleimide, both of which released nitric oxide from cells respiring nitrite, were found to be efficient inhibitors of nitric oxide reductase activity. Control experiments with another uncoupler, pentachlorophenol, showed that the inhibitory effect of CCCP was not the result of a decrease in membrane potential. The denitrification pathway in cells with partly inhibited nitric oxide reductase, or in a reconstituted system containing purified nitric reductase and membrane vesicles, exhibited marked sustained oscillations of nitric oxide concentration. The occurrence of the oscillations was strictly dependent on the initial concentration of nitrite. The observed oscillatory kinetics is considered to reflect two regulatory signals destabilizing the denitrification pathway, namely the inhibition of nitric oxide reductase by nitric oxide and/or by nitrite.
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Affiliation(s)
- I Kucera
- Department of Biochemistry, Faculty of Science, Masaryk University, Brno, Czechoslovakia
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19
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Crump PW, Bisby RH, Cundall RB, Thomas EW. Radiosensitization of E. coli B/r by arylhydrazonopropanedinitriles. Int J Radiat Biol 1989; 55:593-604. [PMID: 2564869 DOI: 10.1080/09553008914550641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Several arylhydrazonopropanedinitriles and an arylhydrazonopropane-diethyl ester (derivatives of well-known uncouplers of oxidative phosphorylation) have been studied with respect to their ability to radiosensitize E. coli B/r under oxic and hypoxic conditions. Of the compounds studied, 2-carboxyphenylhydrazono-propanedinitrile and 2-carboxyphenylhydrazonopropanediethylester were found to be the most efficient radiosensitizers under hypoxia, whilst the former compound was also found to provide radiosensitization under oxic conditions. Increased radiosensitization by 4-carboxyphenylhydrazonopropanedinitrile was observed on decreasing the pH of the irradiation incubation medium. The results are discussed with respect to the physicochemical properties of these compounds and their reactivity with thiols, for which data are presented.
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Affiliation(s)
- P W Crump
- Department of Biological Sciences, University of Salford, U.K
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20
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Podhradský D, Antalík M, Sturdík E. Separation of thiols on Spheron Ara activated with 2-nitrophenyl-hydrazonopropandinitrile ligand. J Chromatogr A 1988; 455:344-8. [PMID: 3235617 DOI: 10.1016/s0021-9673(01)82136-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- D Podhradský
- Department of Special Biology, Faculty of Sciences, P.J. Safárik University, Kosice, Czechoslovakia
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21
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Rastogi D, Nagle WA, Henle KJ, Moss AJ, Rastogi SP. Uncoupling of oxidative phosphorylation does not induce thermotolerance in cultured Chinese hamster cells. Int J Hyperthermia 1988; 4:333-44. [PMID: 3385224 DOI: 10.3109/02656738809051108] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Two uncouplers of oxidative phosphorylation, 2,4-dinitrophenol (DNP) and carbonyl cyanide m-chlorophenylhydrazone (CCCP), were tested for their ability to modify the survival of cultured Chinese hamster ovary (CHO) and Chinese hamster V79 cells treated with hyperthermia. The uncouplers were used under conditions that inhibit oxidative ATP synthesis, as judged from measurements of cellular ATP levels. Incubation of CHO cells in glucose-free Hanks' balanced salt solution (HBSS) containing 1 mM DNP for 1 h at 37 degrees C followed by reincubation at 37 degrees C in complete growth medium for 3 or 16 h, showed no substantial changes in the 45 degrees C heat survival curve as compared to heated cells not exposed to DNP. Thus, DNP treatment of CHO cells did not induce thermotolerance. Carbonyl cyanide m-chlorophenylhydrazone (CCCP), tested under similar experimental conditions, did alter cellular heat resistance. The major change in the 45 degrees C survival curve of CHO cells pretreated with CCCP was an increase in the width of the shoulder: the Dq value increased from 14 min to 24 min, for the control and CCCP-treated cells respectively. The D0 value did not change appreciably. In contrast, heat-induced thermotolerance (10 min, 45 degrees C + 16 h, 37 degrees C) was characterized primarily by an increase in the D0 parameter from 4 min (unheated cells) to 17 min. Similar results were observed with CCCP-treated V79 cells. The data demonstrate that heat resistance induced by 1.2 microM CCCP was manifest as an increased cellular capacity to accumulate and/or repair hyperthermia damage, rather than an induction of thermotolerance, and that this effect probably was not related to the action of CCCP as an uncoupler of oxidative phosphorylation.
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Affiliation(s)
- D Rastogi
- Department of Medicine, University of Arkansas for Medical Sciences, Little Rock
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22
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Sturdík E, Michalcáková S, Hrmová M, Antalík M. Metabolic and physiological consequences of the effect of phenylhydrazonopropanedinitriles on Candida albicans. Folia Microbiol (Praha) 1987; 32:216-25. [PMID: 3114105 DOI: 10.1007/bf02881103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Phenylhydrazonopropanedinitrile, a model uncoupler of oxidative phosphorylation, was used in studies of metabolic and physiological consequences of uncoupling at the cellular level in Candida albicans. Concentrations stimulating respiration induce a faster glucose consumption at a practically unchanged respiratory coefficient. The extracellular production of acids is also without significant changes. When applying higher concentrations of the uncoupler respiration was inhibited, similarly to glucose consumption and acid production. This fact is due to nonspecific interactions of the alkylation type with mercapto groups of functional proteins. Phenylhydrazonopropanedinitrile influences energy-generating processes resulting in slowing down or interruption of biosynthetic processes and occasionally even growth of Candida albicans.
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23
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Grønberg M, Flatmark T. Studies on Mg2+-dependent ATPase in bovine adrenal chromaffin granules. With special reference to the effect of inhibitors and energy coupling. EUROPEAN JOURNAL OF BIOCHEMISTRY 1987; 164:1-8. [PMID: 2881784 DOI: 10.1111/j.1432-1033.1987.tb10983.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The Mg2+-ATPase activities of bovine adrenal chromaffin granules were studied in highly purified preparations of granule ghosts and in intact organelles. The overall ATPase activity (150-250 nmol ADP min-1 mg-1) of the granule ghost preparations was inhibited less than 5% by the bathophenanthroline chelate of Fe(II), a potent inhibitor of mitochondrial F1-ATPase. This small inhibition can be accounted for by a very minor contamination with mitochondria or mitochondrial fragments. The overall ATPase activity of native granule ghosts was inhibited about 75% by N-ethylmaleimide, with half-maximal inhibition at about 20 microM. The titration curve was slightly shifted towards higher concentrations as compared to the inhibition curve for the proton pump activity, which was completely inhibited at 25 microM. N,N'-Dicyclohexylcarbodiimide inhibited the overall ATPase activity by 75-80% at 1.1 mumol/mg protein, a concentration that completely abolished the proton pump activity. Low concentrations (10 microM) of vanadate inhibited the overall ATPase activity by about 15% but had no effect on the proton pump activity, which was partly inhibited only at higher vanadate concentrations. Our attempts to assign a function to the vanadate-sensitive and N-ethylmaleimide-insensitive ATPase have so far been unsuccessful. In particular, our assay for ATP diphosphohydrolase activity was negative, although the chromaffin granule ghosts revealed a low Mg2+-ADPase activity (11.8 nmol AMP min-1 mg-1 protein). In intact chromaffin granules the specific Mg2+-ATPase activity (50-70 nmol ADP min-1 mg-1) was stimulated 2-fold by uncouplers, as compared to 1.6-1.7-fold in granule ghosts. The degree of energy coupling was rather independent of the external pH (6.5 less than pH less than 8.0) and temperature (20-45 degrees C). As expected, partial inhibition (about 15%) of the overall ATPase activity by 10 microM vanadate increased the ATPase control ratio. ADP was found to be a potent inhibitor of the proton pump activity with MgATP as the substrate, and the effect can partly be explained by a competitive type of inhibition of the hydrolytic reaction. This effect of ADP explains some of the kinetic data reported for MgATP-dependent (H+-ATPase-dependent) reactions in this organelle, notably the energy-dependent accumulation and storage of catecholamines.
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Baláz S, Sturdík E, Durcová E, Antalík M, Sulo P. Quantitative structure-activity relationship of carbonylcyanide phenylhydrazones as uncouplers of mitochondrial oxidative phosphorylation. BIOCHIMICA ET BIOPHYSICA ACTA 1986; 851:93-8. [PMID: 3015209 DOI: 10.1016/0005-2728(86)90252-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The dependence of the uncoupling activity in the series of 16 carbonylcyanide phenylhydrazones on their physico-chemical properties (partition coefficient, dissociation constant and rate constant for reaction with thiols) is investigated using two physiologically based models, one for protonophoric mechanism of uncoupling and the other assuming the covalent modification of a membrane constituent to be the key step in this process. As indicated by uptake experiments, at the given conditions a lipophilic-hydrophilic equilibrium is attained without any loss of the compounds via chemical reactions. Using this fact to reduce the number of adjustable parameters, a better fit to the data on stimulation of respiration is obtained with the former (protonophoric) model.
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26
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Haveman J, Li GC, Mak JY, Kipp JB. Chemically induced resistance to heat treatment and stress protein synthesis in cultured mammalian cells. INTERNATIONAL JOURNAL OF RADIATION BIOLOGY AND RELATED STUDIES IN PHYSICS, CHEMISTRY, AND MEDICINE 1986; 50:51-64. [PMID: 3487525 DOI: 10.1080/09553008614550441] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Short exposure (1-2 h) of cultured cells, derived from a transplantable murine mammary carcinoma, to sodium arsenite, 2,4-dinitrophenol (DNP), carbonylcyanide-3-chlorophenylhydrazone (CCP) or disulfiram, induced resistance to a subsequent heat treatment, similar to heat-induced thermotolerance. Optimum resistance to a test heat treatment of 45 min at 45 degrees C after sodium arsenite exposure was obtained at a concentration of 300 microM, after DNP exposure at 3mM, after CCP at 300 microM and after disulfiram exposure in the range 1-30 microM. Exposure of cells to CCP, sodium arsenite or disulfiram led to enhanced synthesis of some proteins with the same molecular weight as 'heat shock' proteins. The pattern of enhanced synthesis of these proteins was agent specific. We could not detect significantly enhanced synthesis of the proteins after DNP using one-dimensional gel electrophoresis. These results suggest that enhanced stress protein synthesis is not a prerequisite for the development of thermal resistance.
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Veit P, Fuchs J, Zimmer G. Uncoupler- and hypoxia-induced damage in the working rat heart and its treatment. I. Observations with uncouplers of oxidative phosphorylation. Basic Res Cardiol 1985; 80:107-15. [PMID: 4004721 DOI: 10.1007/bf01910457] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In the isolated working rat heart, the damaging effect of 0.05-0.06 microM Carbonylcyanide-p-trifluoro-methoxyphenylhydrazone (FCCP) was reversible within 20 sec by perfusion with fresh buffer. Cysteine 3 mM restored the aortic flow to the initial value within an additional 15-20 sec. Thereafter, the FCCP effect became irreversible due to a progressive structural membrane change. The structural change by FCCP is probably brought about by 'internalization' of polar groups (R-SH; R-NH3+) of the mitochondrial (and other) membrane.
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28
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Podhradský D, Toth G, Suchár G, Kristian P, Antalík M. Adsorption of SH-containing amino acids, peptides and proteins on the 2-nitrophenylhydrazonopropanedinitrile derivative of spheron ara. J Chromatogr A 1985. [DOI: 10.1016/s0021-9673(01)87417-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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29
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Culos D, Watanabe M. The effect of carbonyl cyanide m-chlorophenylhydrazone on steroid transport in membrane vesicles of Pseudomonas testosteroni. JOURNAL OF STEROID BIOCHEMISTRY 1983; 19:1127-33. [PMID: 6310264 DOI: 10.1016/0022-4731(83)90406-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The uncoupler carbonyl cyanide chlorophenylhydrazone (CCCP) was an effective inhibitor of steroid transport in membrane vesicles of Pseudomonas testosteroni between 10 microM and 1 microM CCCP. At these concentrations the inhibition of steroid transport was not due to an inhibition of the 3 beta and 17 beta-hydroxysteroid dehydrogenase enzyme. CCCP also affected testosterone-dependent oxygen consumption at concentrations up to 100 microM and inhibited respiration at 0.5 and 1 microM. The effect of CCCP on testosterone-dependent oxygen consumption indicated that CCCP was acting as an uncoupler. The concurrent inhibition of testosterone transport and stimulation of testosterone-dependent oxygen consumption at 10-100 microM CCCP supported the conclusion that transport and metabolism were tightly coupled processes. When membrane vesicles were pre-incubated with CCCP for 15 min, CCCP did inhibit transport and the 3 beta and 17 beta-hydroxysteroid dehydrogenase activity. However, both transport and enzyme inhibition could be prevented by the addition of NAD+ to the incubation mixture. This indicated that CCCP exhibits the properties of a sulfhydryl reagent under pre-incubated conditions.
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30
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Phenylhydrazonopropanedinitrile derivatives of cellulose: New type of sorbent for thiol compounds. ACTA ACUST UNITED AC 1983. [DOI: 10.1016/0167-6989(83)90041-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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31
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Culos D, Watanabe M. The effect of 2,4-dinitrophenol on steroid transport in membrane vesicles of Pseudomonas testosteroni. JOURNAL OF STEROID BIOCHEMISTRY 1983; 18:371-4. [PMID: 6827840 DOI: 10.1016/0022-4731(83)90118-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Steroid transport in Pseudomonas testosteroni membrane vesicles was significantly inhibited by the uncoupled 2,4-dinitrophenol (DNP). Inhibition of steroid transport was not due to inhibition of the 3 beta- and 17 beta-hydroxysteroid dehydrogenase by concentrations of up to 1 mM DNP. However, inhibition of this membrane-bound enzyme was measured at 10 mM DNP. The solubilized 3 beta- and 17 beta-hydroxysteroid dehydrogenase was more sensitive, being inhibited at both 1 and 10 mM DNP indicating a specific inhibition of this enzyme by DNP. Testosterone-dependent oxygen consumption was stimulated slightly at low concentrations of DNP and inhibited at high concentrations. The inhibition of testosterone-dependent oxygen consumption correlated with the inhibition of transport. This indicated that the inhibition of transport by DNP was due to a direct inhibition of metabolism. The existence of an electrochemical gradient is used to explain these results.
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Toninello A, Siliprandi N. Restoration of membrane potential in mitochondria deenergized with carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP). BIOCHIMICA ET BIOPHYSICA ACTA 1982; 682:289-92. [PMID: 7171582 DOI: 10.1016/0005-2728(82)90110-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The membrane potential (delta psi) of rat liver mitochondria dropped upon addition of carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP) but was gradually and fully restored to the original value by the subsequent addition of dithioerythritol. Concomitantly, Ca2+ released from mitochondria was reaccumulated and the oxidative phosphorylation process completely recoupled. Neither of these effects has been observed with dinitro-o-cresol or 2,4-dinitrophenol, uncouplers which, unlike FCCP, do not react with thiols. Delta psi abolished by FCCP was also restored, though incompletely, by albumin; a prompt and complete restoration was however achieved upon subsequent addition of dithioerythritol. Dithioerythritol also completely and rapidly restored the delta psi decreased by addition of diazene dicarboxylic acid bisdimethylamide (diamide).
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