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Richardson KH, Seif-Eddine M, Sills A, Roessler MM. Controlling and exploiting intrinsic unpaired electrons in metalloproteins. Methods Enzymol 2022; 666:233-296. [PMID: 35465921 DOI: 10.1016/bs.mie.2022.02.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Electron paramagnetic resonance spectroscopy encompasses a versatile set of techniques that allow detailed insight into intrinsically occurring paramagnetic centers in metalloproteins and enzymes that undergo oxidation-reduction reactions. In this chapter, we discuss the process from isolating the protein to acquiring and analyzing pulse EPR spectra, adopting a practical perspective. We start with considerations when preparing the protein sample, explain techniques and procedures available for determining the reduction potential of the redox-active center of interest and provide details on methodologies to trap a given paramagnetic state for detailed pulse EPR studies, with an emphasis on biochemical and spectroscopic tools available when multiple EPR-active species are present. We elaborate on some of the most commonly used pulse EPR techniques and the choices the user has to make, considering advantages and disadvantages and how to avoid pitfalls. Examples are provided throughout.
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Affiliation(s)
| | - Maryam Seif-Eddine
- Imperial College London, Molecular Sciences Research Hub, London, United Kingdom
| | - Adam Sills
- Imperial College London, Molecular Sciences Research Hub, London, United Kingdom
| | - Maxie M Roessler
- Imperial College London, Molecular Sciences Research Hub, London, United Kingdom.
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2
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A salvage pathway maintains highly functional respiratory complex I. Nat Commun 2020; 11:1643. [PMID: 32242014 PMCID: PMC7118099 DOI: 10.1038/s41467-020-15467-7] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 03/05/2020] [Indexed: 02/07/2023] Open
Abstract
Regulation of the turnover of complex I (CI), the largest mitochondrial respiratory chain complex, remains enigmatic despite huge advancement in understanding its structure and the assembly. Here, we report that the NADH-oxidizing N-module of CI is turned over at a higher rate and largely independently of the rest of the complex by mitochondrial matrix protease ClpXP, which selectively removes and degrades damaged subunits. The observed mechanism seems to be a safeguard against the accumulation of dysfunctional CI arising from the inactivation of the N-module subunits due to attrition caused by its constant activity under physiological conditions. This CI salvage pathway maintains highly functional CI through a favorable mechanism that demands much lower energetic cost than de novo synthesis and reassembly of the entire CI. Our results also identify ClpXP activity as an unforeseen target for therapeutic interventions in the large group of mitochondrial diseases characterized by the CI instability. Maintenance and quality control of the mitochondrial respiratory chain complexes responsible for bulk energy production are unclear. Here, the authors show that the mitochondrial protease ClpXP is required for the rapid turnover of the core N-module of respiratory complex I, which happens independently of other modules in the complex.
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Ivanov MY, Fedin MV. Nanoscale heterogeneities in ionic liquids: insights from EPR of spin probes. MENDELEEV COMMUNICATIONS 2018. [DOI: 10.1016/j.mencom.2018.11.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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4
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Studying structure and function of membrane proteins with PELDOR/DEER spectroscopy – The crystallographers’ perspective. Methods 2018; 147:163-175. [DOI: 10.1016/j.ymeth.2018.03.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 02/20/2018] [Accepted: 03/01/2018] [Indexed: 12/16/2022] Open
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5
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Twig Y, Sorkin A, Cristea D, Feintuch A, Blank A. Surface loop-gap resonators for electron spin resonance at W-band. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2017; 88:123901. [PMID: 29289191 DOI: 10.1063/1.5000946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Electron spin resonance (ESR) is a spectroscopic method used to detect paramagnetic materials, reveal their structure, and also image their position in a sample. ESR makes use of a large static magnetic field to split the energy levels of the electron magnetic moment of the paramagnetic species. A strong microwave magnetic field is applied to excite the spins, and subsequently the ESR system detects their faint microwave signal response. The sensitivity of an ESR system is greatly influenced by the magnitude of the static field and the properties of the microwave resonator used to detect the spin signal. In general terms, the higher the static field (microwave frequency) and the smaller the resonator, the more sensitive the system will be. Previous work aimed at high-sensitivity ESR was focused on the development and testing of very small resonators operating at moderate magnetic fields in the range of ∼0.1-1.2 T (maximum frequency of ∼35 GHz). Here, we describe the design, construction, and testing of recently developed miniature surface loop-gap resonators used in ESR and operating at a much higher frequency of ∼95 GHz (W-band, corresponding to a field of ∼3.4 T). Such resonators can greatly enhance the sensitivity of ESR and also improve the resulting spectral resolution due to the higher static field employed. A detailed description of the resonator's design and coupling mechanism, as well as the supporting probe head, is provided. We also discuss the production method of the resonators and probe head and, in the end, provide preliminary experimental results that show the setup's high spin sensitivity and compare it to theoretical predictions.
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Affiliation(s)
- Ygal Twig
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Anton Sorkin
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - David Cristea
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Akiva Feintuch
- Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Aharon Blank
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa 32000, Israel
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6
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Maio N, Rouault TA. Mammalian Fe-S proteins: definition of a consensus motif recognized by the co-chaperone HSC20. Metallomics 2017; 8:1032-1046. [PMID: 27714045 DOI: 10.1039/c6mt00167j] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Iron-sulfur (Fe-S) clusters are inorganic cofactors that are fundamental to several biological processes in all three kingdoms of life. In most organisms, Fe-S clusters are initially assembled on a scaffold protein, ISCU, and subsequently transferred to target proteins or to intermediate carriers by a dedicated chaperone/co-chaperone system. The delivery of assembled Fe-S clusters to recipient proteins is a crucial step in the biogenesis of Fe-S proteins, and, in mammals, it relies on the activity of a multiprotein transfer complex that contains the chaperone HSPA9, the co-chaperone HSC20 and the scaffold ISCU. How the transfer complex efficiently engages recipient Fe-S target proteins involves specific protein interactions that are not fully understood. This mini review focuses on recent insights into the molecular mechanism of amino acid motif recognition and discrimination by the co-chaperone HSC20, which guides Fe-S cluster delivery.
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Affiliation(s)
- N Maio
- Molecular Medicine Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, 9000 Rockville Pike, 20892 Bethesda, MD, USA.
| | - T A Rouault
- Molecular Medicine Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, 9000 Rockville Pike, 20892 Bethesda, MD, USA.
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7
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Le Breton N, Wright JJ, Jones AJY, Salvadori E, Bridges HR, Hirst J, Roessler MM. Using Hyperfine Electron Paramagnetic Resonance Spectroscopy to Define the Proton-Coupled Electron Transfer Reaction at Fe-S Cluster N2 in Respiratory Complex I. J Am Chem Soc 2017; 139:16319-16326. [PMID: 29039928 DOI: 10.1021/jacs.7b09261] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Energy-transducing respiratory complex I (NADH:ubiquinone oxidoreductase) is one of the largest and most complicated enzymes in mammalian cells. Here, we used hyperfine electron paramagnetic resonance (EPR) spectroscopic methods, combined with site-directed mutagenesis, to determine the mechanism of a single proton-coupled electron transfer reaction at one of eight iron-sulfur clusters in complex I, [4Fe-4S] cluster N2. N2 is the terminal cluster of the enzyme's intramolecular electron-transfer chain and the electron donor to ubiquinone. Because of its position and pH-dependent reduction potential, N2 has long been considered a candidate for the elusive "energy-coupling" site in complex I at which energy generated by the redox reaction is used to initiate proton translocation. Here, we used hyperfine sublevel correlation (HYSCORE) spectroscopy, including relaxation-filtered hyperfine and single-matched resonance transfer (SMART) HYSCORE, to detect two weakly coupled exchangeable protons near N2. We assign the larger coupling with A(1H) = [-3.0, -3.0, 8.7] MHz to the exchangeable proton of a conserved histidine and conclude that the histidine is hydrogen-bonded to N2, tuning its reduction potential. The histidine protonation state responds to the cluster oxidation state, but the two are not coupled sufficiently strongly to catalyze a stoichiometric and efficient energy transduction reaction. We thus exclude cluster N2, despite its proton-coupled electron transfer chemistry, as the energy-coupling site in complex I. Our work demonstrates the capability of pulse EPR methods for providing detailed information on the properties of individual protons in even the most challenging of energy-converting enzymes.
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Affiliation(s)
- Nolwenn Le Breton
- School of Biological and Chemical Sciences, Queen Mary University of London , Mile End Road, London, E1 4NS, United Kingdom
| | - John J Wright
- School of Biological and Chemical Sciences, Queen Mary University of London , Mile End Road, London, E1 4NS, United Kingdom
| | - Andrew J Y Jones
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge , Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, United Kingdom
| | - Enrico Salvadori
- School of Biological and Chemical Sciences, Queen Mary University of London , Mile End Road, London, E1 4NS, United Kingdom.,London Centre for Nanotechnology, University College London , 17-19 Gordon Street, London WC1H 0AH, United Kingdom
| | - Hannah R Bridges
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge , Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, United Kingdom
| | - Judy Hirst
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge , Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, United Kingdom
| | - Maxie M Roessler
- School of Biological and Chemical Sciences, Queen Mary University of London , Mile End Road, London, E1 4NS, United Kingdom
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8
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Spindler PE, Schöps P, Kallies W, Glaser SJ, Prisner TF. Perspectives of shaped pulses for EPR spectroscopy. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2017; 280:30-45. [PMID: 28579101 DOI: 10.1016/j.jmr.2017.02.023] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Revised: 02/27/2017] [Accepted: 02/28/2017] [Indexed: 06/07/2023]
Abstract
This article describes current uses of shaped pulses, generated by an arbitrary waveform generator, in the field of EPR spectroscopy. We show applications of sech/tanh and WURST pulses to dipolar spectroscopy, including new pulse schemes and procedures, and discuss the more general concept of optimum-control-based pulses for applications in EPR spectroscopy. The article also describes a procedure to correct for experimental imperfections, mostly introduced by the microwave resonator, and discusses further potential applications and limitations of such pulses.
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Affiliation(s)
- Philipp E Spindler
- Institute of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic Resonance, Goethe University Frankfurt, Germany
| | - Philipp Schöps
- Institute of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic Resonance, Goethe University Frankfurt, Germany
| | - Wolfgang Kallies
- Department of Chemistry, Technical University of Munich, Germany
| | - Steffen J Glaser
- Department of Chemistry, Technical University of Munich, Germany
| | - Thomas F Prisner
- Institute of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic Resonance, Goethe University Frankfurt, Germany.
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9
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Bennett B, Helbling D, Meng H, Jarzembowski J, Geurts AM, Friederich MW, Van Hove JLK, Lawlor MW, Dimmock DP. Potentially diagnostic electron paramagnetic resonance spectra elucidate the underlying mechanism of mitochondrial dysfunction in the deoxyguanosine kinase deficient rat model of a genetic mitochondrial DNA depletion syndrome. Free Radic Biol Med 2016; 92:141-151. [PMID: 26773591 PMCID: PMC5047058 DOI: 10.1016/j.freeradbiomed.2016.01.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 01/04/2016] [Accepted: 01/06/2016] [Indexed: 01/19/2023]
Abstract
A novel rat model for a well-characterized human mitochondrial disease, mitochondrial DNA depletion syndrome with associated deoxyguanosine kinase (DGUOK) deficiency, is described. The rat model recapitulates the pathologic and biochemical signatures of the human disease. The application of electron paramagnetic (spin) resonance (EPR) spectroscopy to the identification and characterization of respiratory chain abnormalities in the mitochondria from freshly frozen tissue of the mitochondrial disease model rat is introduced. EPR is shown to be a sensitive technique for detecting mitochondrial functional abnormalities in situ and, here, is particularly useful in characterizing the redox state changes and oxidative stress that can result from depressed expression and/or diminished specific activity of the distinct respiratory chain complexes. As EPR requires no sample preparation or non-physiological reagents, it provides information on the status of the mitochondrion as it was in the functioning state. On its own, this information is of use in identifying respiratory chain dysfunction; in conjunction with other techniques, the information from EPR shows how the respiratory chain is affected at the molecular level by the dysfunction. It is proposed that EPR has a role in mechanistic pathophysiological studies of mitochondrial disease and could be used to study the impact of new treatment modalities or as an additional diagnostic tool.
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Affiliation(s)
- Brian Bennett
- National Biomedical EPR Center, Department of Biophysics, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.
| | - Daniel Helbling
- Human Molecular Genetics Center and Division of Genetics, Department of Pediatrics, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.
| | - Hui Meng
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.
| | - Jason Jarzembowski
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.
| | - Aron M Geurts
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.
| | - Marisa W Friederich
- Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado, Mailstop 8400, 13121 East 17th Avenue, Aurora, CO 80045, USA.
| | - Johan L K Van Hove
- Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado, Mailstop 8400, 13121 East 17th Avenue, Aurora, CO 80045, USA.
| | - Michael W Lawlor
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.
| | - David P Dimmock
- Human Molecular Genetics Center and Division of Genetics, Department of Pediatrics, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.
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van Wonderen JH, Kostrz DN, Dennison C, MacMillan F. Refined distances between paramagnetic centers of a multi-copper nitrite reductase determined by pulsed EPR (iDEER) spectroscopy. Angew Chem Int Ed Engl 2013; 52:1990-3. [PMID: 23296685 PMCID: PMC3596801 DOI: 10.1002/anie.201208166] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Indexed: 11/12/2022]
Affiliation(s)
- Jessica H van Wonderen
- Henry Wellcome Unit of Biological EPR, School of Chemistry, University of East Anglia, Norwich, UK
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11
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van Wonderen JH, Kostrz DN, Dennison C, MacMillan F. Refined Distances Between Paramagnetic Centers of a Multi-Copper Nitrite Reductase Determined by Pulsed EPR (iDEER) Spectroscopy. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201208166] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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12
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Bridges HR, Bill E, Hirst J. Mössbauer spectroscopy on respiratory complex I: the iron-sulfur cluster ensemble in the NADH-reduced enzyme is partially oxidized. Biochemistry 2011; 51:149-58. [PMID: 22122402 PMCID: PMC3254188 DOI: 10.1021/bi201644x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
In mitochondria, complex I (NADH:quinone oxidoreductase)
couples
electron transfer to proton translocation across an energy-transducing
membrane. It contains a flavin mononucleotide to oxidize NADH, and
an unusually long series of iron–sulfur (FeS) clusters that
transfer the electrons to quinone. Understanding electron transfer
in complex I requires spectroscopic and structural data to be combined
to reveal the properties of individual clusters and of the ensemble.
EPR studies on complex I from Bos taurus have established
that five clusters (positions 1, 2, 3, 5, and 7 along the seven-cluster
chain extending from the flavin) are (at least partially) reduced
by NADH. The other three clusters, positions 4 and 6 plus a cluster
on the other side of the flavin, are not observed in EPR spectra from
the NADH-reduced enzyme: they may remain oxidized, have unusual or
coupled spin states, or their EPR signals may be too fast relaxing.
Here, we use Mössbauer spectroscopy on 57Fe-labeled
complex I from the mitochondria of Yarrowia lipolytica to show that the cluster ensemble is only partially reduced in the
NADH-reduced enzyme. The three EPR-silent clusters are oxidized, and
only the terminal 4Fe cluster (position 7) is fully reduced. Together
with the EPR analyses, our results reveal an alternating profile of
higher and lower potential clusters between the two active sites in
complex I; they are not consistent with the consensus picture of a
set of isopotential clusters. The implications for intramolecular
electron transfer along the extended chain of cofactors in complex
I are discussed.
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Affiliation(s)
- Hannah R Bridges
- Medical Research Council Mitochondrial Biology Unit, Wellcome Trust/MRC Building, Cambridge, CB2 0XY, UK
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