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Fernández M, Marín R, Ruette F. Antioxidant Activity of MgSO 4 Ion Pairs by Spin-Electron Stabilization of Hydroxyl Radicals through DFT Calculations: Biological Relevance. ACS OMEGA 2024; 9:36640-36647. [PMID: 39220510 PMCID: PMC11360028 DOI: 10.1021/acsomega.4c05053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Revised: 08/07/2024] [Accepted: 08/09/2024] [Indexed: 09/04/2024]
Abstract
Magnesium sulfate has been of great interest as an antioxidant for its ability to decrease the oxidizing capacity of the hydroxyl radical. Previously, it was shown that the contact ion pair of this salt could stabilize •OH by coordinating with Mg and delocalizing the unpaired electron over sulfate. The present study explores in detail the MgSO4 antioxidant properties, considering all its ion pairs with •OH in different conformations. The analyses were based on structural, spin, and energetic properties using the DFT approach. As a result, the high antioxidant potential of MgSO4 is related to the spin-electron transfer from SO4 -2 to •OH causing electron spin delocalization and electrostatic stabilization. This transfer occurs for all ion pairs when •OH approaches the Mg first solvation shell, without being coordinated to Mg. The direct Mg-•OH interaction further stabilizes the radical system. These results show that spin-electron transfers are feasible in all hydrated ion pairs MgSO4-•OH, even at a •OH-sulfate distance greater than 10 Å.
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Affiliation(s)
- Miguel Fernández
- Laboratorio
de Química Computacional, Centro de Química, Instituto Venezolano de Investigaciones Científicas
(IVIC), Apartado Postal 21827, Caracas 1020A, Venezuela
| | - Reinaldo Marín
- Laboratorio
de Bioenergética Celular, Centro de Biofísica y Bioquímica, Instituto Venezolano de Investigaciones Científicas
(IVIC), Apartado Postal
21827, Caracas 1020A, Venezuela
| | - Fernando Ruette
- Laboratorio
de Química Computacional, Centro de Química, Instituto Venezolano de Investigaciones Científicas
(IVIC), Apartado Postal 21827, Caracas 1020A, Venezuela
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2
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Rossetto D, Cvjetan N, Walde P, Mansy SS. Protocellular Heme and Iron-Sulfur Clusters. Acc Chem Res 2024; 57:2293-2302. [PMID: 39099316 PMCID: PMC11339926 DOI: 10.1021/acs.accounts.4c00254] [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] [Received: 04/30/2024] [Revised: 07/10/2024] [Accepted: 07/25/2024] [Indexed: 08/06/2024]
Abstract
ConspectusCentral to the quest of understanding the emergence of life is to uncover the role of metals, particularly iron, in shaping prebiotic chemistry. Iron, as the most abundant of the accessible transition metals on the prebiotic Earth, played a pivotal role in early biochemical processes and continues to be indispensable to modern biology. Here, we discuss our recent contributions to probing the plausibility of prebiotic complexes with iron, including heme and iron-sulfur clusters, in mediating chemistry beneficial to a protocell. Laboratory experiments and spectroscopic findings suggest plausible pathways, often facilitated by UV light, for the synthesis of heme and iron-sulfur clusters. Once formed, heme displays catalytic, peroxidase-like activity when complexed with amphiphiles. This activity could have been beneficial in two ways. First, heme could have catalytically removed a molecule (H2O2) that could have had degradative effects on a protocell. Second, heme could have helped in the synthesis of the building blocks of life by coupling the reduction of H2O2 with the oxidation of organic substrates. The necessity of amphiphiles to avoid the formation of inactive complexes of heme is telling, as the modern-day electron transport chain possesses heme embedded within a lipid membrane. Conversely, prebiotic iron-sulfur peptides have yet to be reported to partition into lipid membranes, nor have simple iron-sulfur peptides been found to be capable of participating in the synthesis of organic molecules. Instead, iron-sulfur peptides span a wide range of reduction potentials complementary to the reduction potentials of hemes. The reduction potential of iron-sulfur peptides can be tuned by the type of iron-sulfur cluster formed, e.g., [2Fe-2S] versus [4Fe-4S], or by the substitution of ligands to the metal center. Since iron-sulfur clusters easily form upon stochastic encounters between iron ions, hydrosulfide, and small organic molecules possessing a thiolate, including peptides, the likelihood of soluble iron-sulfur clusters seems to be high. What remains challenging to determine is if iron-sulfur peptides participated in early prebiotic chemistry or were recruited later when protocellular membranes evolved that were compatible with the exploitation of electron transfer for the storage of energy as a proton gradient. This problem mirrors in some ways the difficulty in deciphering the origins of metabolism as a whole. Chemistry that resembles some facets of extant metabolism must have transpired on the prebiotic Earth, but there are few clues as to how and when such chemistry was harnessed to support a (proto)cell. Ultimately, unraveling the roles of hemes and iron-sulfur clusters in prebiotic chemistry promises to deepen our understanding of the origins of life on Earth and aids the search for life elsewhere in the universe.
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Affiliation(s)
- Daniele Rossetto
- Department
of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, AlbertaT6G 2G2, Canada
- D-CIBIO, University of Trento, via Sommarive 9, Trento 38123, Italy
| | - Nemanja Cvjetan
- Department
of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, AlbertaT6G 2G2, Canada
- Department
of Materials, ETH Zürich, Leopold-Ruzicka-Weg 4, Zürich 8093, Switzerland
| | - Peter Walde
- Department
of Materials, ETH Zürich, Leopold-Ruzicka-Weg 4, Zürich 8093, Switzerland
| | - Sheref S. Mansy
- Department
of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, AlbertaT6G 2G2, Canada
- D-CIBIO, University of Trento, via Sommarive 9, Trento 38123, Italy
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3
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Custódio TF, Guédez G, Löw C. Transient Co-expression of Membrane Protein Complexes in Mammalian Cells. Methods Mol Biol 2024; 2810:11-28. [PMID: 38926270 DOI: 10.1007/978-1-0716-3878-1_2] [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] [Indexed: 06/28/2024]
Abstract
Membrane proteins are essential components of biological membranes with key roles in cellular processes such as nutrient transport, cell communication, signaling, or energy conversion. Due to their crucial functions, membrane proteins and their complexes are often targets for therapeutic interventions. Expression and purification of membrane proteins are often a bottleneck to yield sufficient material for structural studies and further downstream characterization. Taking advantage of the Expi293 expression system for the production of eukaryotic proteins, we present a very efficient and fast protocol for the co-expression of a membrane complex. Here, we use transient transfection to co-express the membrane transporter PHT1 with its adaptor protein TASL. To allow the simultaneous screening of different proteins, constructs, or interaction partners, we make use of the Twin-Strep magnetic system. The protocol can be applied for small-scale screening of any membrane protein alone or co-expressed with interacting partners followed by large-scale production and purification of a potential membrane protein complex.
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Affiliation(s)
- Tânia F Custódio
- Centre for Structural Systems Biology (CSSB), Hamburg, Germany.
- European Molecular Biology Laboratory (EMBL) Hamburg, Hamburg, Germany.
| | - Gabriela Guédez
- Centre for Structural Systems Biology (CSSB), Hamburg, Germany
- European Molecular Biology Laboratory (EMBL) Hamburg, Hamburg, Germany
| | - Christian Löw
- Centre for Structural Systems Biology (CSSB), Hamburg, Germany.
- European Molecular Biology Laboratory (EMBL) Hamburg, Hamburg, Germany.
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4
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Haxhija J, Guischard F, Koslowski T. A trick of the tail: computing the entropic contribution to the energetics of quinone-protein unbindung. Phys Chem Chem Phys 2023; 25:27498-27505. [PMID: 37800323 DOI: 10.1039/d3cp03466f] [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: 10/07/2023]
Abstract
We estimate the entropic contributions to the free energy of quinone unbinding in bacterial and mitochondrial respiratory chains using molecular dynamics (MD) and Monte Carlo (MC) computer simulations. For a varying length of the isoprenoid side chain, MD simulations in lipid bilayers and in unpolar solvents are used to assess the dihedral angle distributions along the chain. These form the basis of a MC estimate of the number of molecular structures that do not exhibit steric self-overlap and that are confined to the bilayer. We obtain an entropy drive of TΔS = 1.4 kcal mol-1 for each isoprene unit, which in sum is comparable to the redox potential differences involved in respiratory chain electron transfer. We postulate an entropy-driven zipper for quinone unbinding and discuss it in the context of the bioenergetics and the structure of complex I, and we indicate possible consequences of our findings for MD-based free energy computations.
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Affiliation(s)
- Jetmir Haxhija
- Institut für Physikalische Chemie, Universität Freiburg, Albertstrasse 21, 79104 Freiburg, Germany.
| | - Felix Guischard
- Institut für Physikalische Chemie, Universität Freiburg, Albertstrasse 21, 79104 Freiburg, Germany.
| | - Thorsten Koslowski
- Institut für Physikalische Chemie, Universität Freiburg, Albertstrasse 21, 79104 Freiburg, Germany.
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5
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Abstract
The theory of electron transfer reactions establishes the conceptual foundation for redox solution chemistry, electrochemistry, and bioenergetics. Electron and proton transfer across the cellular membrane provide all energy of life gained through natural photosynthesis and mitochondrial respiration. Rates of biological charge transfer set kinetic bottlenecks for biological energy storage. The main system-specific parameter determining the activation barrier for a single electron-transfer hop is the reorganization energy of the medium. Both harvesting of light energy in natural and artificial photosynthesis and efficient electron transport in biological energy chains require reduction of the reorganization energy to allow fast transitions. This review article discusses mechanisms by which small values of the reorganization energy are achieved in protein electron transfer and how similar mechanisms can operate in other media, such as nonpolar and ionic liquids. One of the major mechanisms of reorganization energy reduction is through non-Gibbsian (nonergodic) sampling of the medium configurations on the reaction time. A number of alternative mechanisms, such as electrowetting of active sites of proteins, give rise to non-parabolic free energy surfaces of electron transfer. These mechanisms, and nonequilibrium population of donor-acceptor vibrations, lead to a universal phenomenology of separation between the Stokes shift and variance reorganization energies of electron transfer.
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Affiliation(s)
- Dmitry V Matyushov
- School of Molecular Sciences and Department of Physics, Arizona State University, PO Box 871504, Tempe, Arizona 85287-1504, USA.
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6
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Gavryushov S, Kuzmich NN, Polyakov KM. Quantum Mechanical Study of Oxygen Ligands Protonation for the Stable States of the Laccase Active Site. Int J Mol Sci 2023; 24:2990. [PMID: 36769314 PMCID: PMC9917769 DOI: 10.3390/ijms24032990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Revised: 01/29/2023] [Accepted: 01/31/2023] [Indexed: 02/05/2023] Open
Abstract
Laccases are enzymes catalyzing the oxidation of a wide range of organic and inorganic substrates accompanied by molecular oxygen reduction to water. Recently, oxygen reduction by laccases has been studied by single-crystal serial X-ray crystallography with increasing absorption doses at subatomic resolution. There were two determined structures corresponding to the reduced and oxidized stable states of the laccase active site. However, the protonation of the oxygen ligands involved cannot be determined even at subatomic resolution. In the present work, the protonation of oxygen ligands in the active site of laccase for the two stable states determined in the X-ray study was explored using quantum mechanical and continuum-electrostatics calculations. This is important for understanding the reaction of the oxygen reduction mechanism in laccases. The high precision of X-ray data at subatomic resolutions allowed us to optimize the quantum mechanical calculations.
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Affiliation(s)
- Sergei Gavryushov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilova Str. 32, 119334 Moscow, Russia
- Institute for Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University, 2-4 Bolshaya Pirogovskaya Str., 119991 Moscow, Russia
| | - Nikolay N. Kuzmich
- Institute for Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University, 2-4 Bolshaya Pirogovskaya Str., 119991 Moscow, Russia
- Smorodintsev Research Institute of Influenza, WHO National Influenza Centre of Russia, 15/17 Professor Popov Str., 197376 Saint-Petersburg, Russia
| | - Konstantin M. Polyakov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilova Str. 32, 119334 Moscow, Russia
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7
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Sarhangi SM, Matyushov DV. Theory of Protein Charge Transfer: Electron Transfer between Tryptophan Residue and Active Site of Azurin. J Phys Chem B 2022; 126:10360-10373. [PMID: 36459590 DOI: 10.1021/acs.jpcb.2c05258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
One reaction step in the conductivity relay of azurin, electron transfer between the Cu-based active site and the tryptophan residue, is studied theoretically and by classical molecular dynamics simulations. Oxidation of tryptophan results in electrowetting of this residue. This structural change makes the free energy surfaces of electron transfer nonparabolic as described by the Q-model of electron transfer. We analyze the medium dynamical effect on protein electron transfer produced by coupled Stokes-shift dynamics and the dynamics of the donor-acceptor distance modulating electron tunneling. The equilibrium donor-acceptor distance falls in the plateau region of the rate constant, where it is determined by the protein-water dynamics, and the probability of electron tunneling does not affect the rate. The crossover distance found here puts most intraprotein electron-transfer reactions under the umbrella of dynamical control. The crossover between the medium-controlled and tunneling-controlled kinetics is combined with the effect of the protein-water medium on the activation barrier to formulate principles of tunability of protein-based charge-transfer chains. The main principle in optimizing the activation barrier is the departure from the Gaussian-Gibbsian statistics of fluctuations promoting activated transitions. This is achieved either by incomplete (nonergodic) sampling, breaking the link between the Stokes-shift and variance reorganization energies, or through wetting-induced structural changes of the enzyme's active site.
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Affiliation(s)
- Setare Mostajabi Sarhangi
- School of Molecular Sciences and Department of Physics, Arizona State University, PO Box 871504, Tempe, Arizona85287-1504, United States
| | - Dmitry V Matyushov
- School of Molecular Sciences and Department of Physics, Arizona State University, PO Box 871504, Tempe, Arizona85287-1504, United States
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8
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Nunn AV, Guy GW, Bell JD. Bioelectric Fields at the Beginnings of Life. Bioelectricity 2022; 4:237-247. [PMID: 36636557 PMCID: PMC9810354 DOI: 10.1089/bioe.2022.0012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The consensus on the origins of life is that it involved organization of prebiotic chemicals according to the underlying principles of thermodynamics to dissipate energy derived from photochemical and/or geochemical sources. Leading theories tend to be chemistry-centric, revolving around either metabolism or information-containing polymers first. However, experimental data also suggest that bioelectricity and quantum effects play an important role in biology, which might suggest that a further factor is required to explain how life began. Intriguingly, in the early part of 20th century, the concept of the "morphogenetic field" was proposed by Gurwitsch to explain how the shape of an organism was determined, while a role for quantum mechanics in biology was suggested by Bohr and Schrödinger, among others. This raises the question as to the potential of these phenomena, especially bioelectric fields, to have been involved in the origin of life. It points to the possibility that as bioelectricity is universally prevalent in biological systems today, it represents a more complex echo of an electromagnetic skeleton which helped shape life into being. It could be argued that as a flow of ions creates an electric field, this could have been pivotal in the formation of an energy dissipating structure, for instance, in deep sea thermal vents. Moreover, a field theory might also hint at the potential involvement of nontrivial quantum effects in life. Not only might this perspective help indicate the origins of morphogenetic fields, but also perhaps suggest where life may have started, and whether metabolism or information came first. It might also help to provide an insight into aging, cancer, consciousness, and, perhaps, how we might identify life beyond our planet. In short, when thinking about life, not only do we have to consider the accepted chemistry, but also the fields that must also shape it. In effect, to fully understand life, as well as the yin of accepted particle-based chemistry, there is a yang of field-based interaction and an ethereal skeleton.
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Affiliation(s)
- Alistair V.W. Nunn
- Research Centre for Optimal Health, Department of Life Sciences, University of Westminster, London, United Kingdom.,Address correspondence to: Alistair V.W. Nunn, PhD, Research Centre for Optimal Health, Department of Life Sciences, University of Westminster, London W1W 6UW, United Kingdom
| | | | - Jimmy D. Bell
- Research Centre for Optimal Health, Department of Life Sciences, University of Westminster, London, United Kingdom
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9
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Steward KF, Payne D, Kincannon W, Johnson C, Lensing M, Fausset H, Németh B, Shepard EM, Broderick WE, Broderick JB, Dubois J, Bothner B. Proteomic Analysis of Methanococcus voltae Grown in the Presence of Mineral and Nonmineral Sources of Iron and Sulfur. Microbiol Spectr 2022; 10:e0189322. [PMID: 35876569 PMCID: PMC9431491 DOI: 10.1128/spectrum.01893-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 06/17/2022] [Indexed: 11/28/2022] Open
Abstract
Iron sulfur (Fe-S) proteins are essential and ubiquitous across all domains of life, yet the mechanisms underpinning assimilation of iron (Fe) and sulfur (S) and biogenesis of Fe-S clusters are poorly understood. This is particularly true for anaerobic methanogenic archaea, which are known to employ more Fe-S proteins than other prokaryotes. Here, we utilized a deep proteomics analysis of Methanococcus voltae A3 cultured in the presence of either synthetic pyrite (FeS2) or aqueous forms of ferrous iron and sulfide to elucidate physiological responses to growth on mineral or nonmineral sources of Fe and S. The liquid chromatography-mass spectrometry (LCMS) shotgun proteomics analysis included 77% of the predicted proteome. Through a comparative analysis of intra- and extracellular proteomes, candidate proteins associated with FeS2 reductive dissolution, Fe and S acquisition, and the subsequent transport, trafficking, and storage of Fe and S were identified. The proteomic response shows a large and balanced change, suggesting that M. voltae makes physiological adjustments involving a range of biochemical processes based on the available nutrient source. Among the proteins differentially regulated were members of core methanogenesis, oxidoreductases, membrane proteins putatively involved in transport, Fe-S binding ferredoxin and radical S-adenosylmethionine proteins, ribosomal proteins, and intracellular proteins involved in Fe-S cluster assembly and storage. This work improves our understanding of ancient biogeochemical processes and can support efforts in biomining of minerals. IMPORTANCE Clusters of iron and sulfur are key components of the active sites of enzymes that facilitate microbial conversion of light or electrical energy into chemical bonds. The proteins responsible for transporting iron and sulfur into cells and assembling these elements into metal clusters are not well understood. Using a microorganism that has an unusually high demand for iron and sulfur, we conducted a global investigation of cellular proteins and how they change based on the mineral forms of iron and sulfur. Understanding this process will answer questions about life on early earth and has application in biomining and sustainable sources of energy.
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Affiliation(s)
- Katherine F. Steward
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Devon Payne
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, Montana, USA
| | - Will Kincannon
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Christina Johnson
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Malachi Lensing
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Hunter Fausset
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Brigitta Németh
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Eric M. Shepard
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - William E. Broderick
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Joan B. Broderick
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Jen Dubois
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Brian Bothner
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
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10
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Sarhangi SM, Matyushov DV. Anomalously Small Reorganization Energy of the Half Redox Reaction of Azurin. J Phys Chem B 2022; 126:3000-3011. [DOI: 10.1021/acs.jpcb.2c00338] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Setare M. Sarhangi
- Department of Physics, Arizona State University, P.O. Box 871504, Tempe, Arizona 85287-1504, United States
| | - Dmitry V. Matyushov
- School of Molecular Sciences and Department of Physics, Arizona State University, P.O. Box 871504, Tempe, Arizona 85287-1504, United States
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11
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Juhász L, Tallósy SP, Nászai A, Varga G, Érces D, Boros M. Bioactivity of Inhaled Methane and Interactions With Other Biological Gases. Front Cell Dev Biol 2022; 9:824749. [PMID: 35071248 PMCID: PMC8777024 DOI: 10.3389/fcell.2021.824749] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 12/14/2021] [Indexed: 01/04/2023] Open
Abstract
A number of studies have demonstrated explicit bioactivity for exogenous methane (CH4), even though it is conventionally considered as physiologically inert. Other reports cited in this review have demonstrated that inhaled, normoxic air-CH4 mixtures can modulate the in vivo pathways involved in oxidative and nitrosative stress responses and key events of mitochondrial respiration and apoptosis. The overview is divided into two parts, the first being devoted to a brief review of the effects of biologically important gases in the context of hypoxia, while the second part deals with CH4 bioactivity. Finally, the consequence of exogenous, normoxic CH4 administration is discussed under experimental hypoxia- or ischaemia-linked conditions and in interactions between CH4 and other biological gases, with a special emphasis on its versatile effects demonstrated in pulmonary pathologies.
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Affiliation(s)
- László Juhász
- Institute of Surgical Research, Faculty of Medicine, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
| | - Szabolcs Péter Tallósy
- Institute of Surgical Research, Faculty of Medicine, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
| | - Anna Nászai
- Institute of Surgical Research, Faculty of Medicine, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
| | - Gabriella Varga
- Institute of Surgical Research, Faculty of Medicine, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
| | - Dániel Érces
- Institute of Surgical Research, Faculty of Medicine, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
| | - Mihály Boros
- Institute of Surgical Research, Faculty of Medicine, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
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12
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Manna S, Kong WJ, Bäckvall JE. Iron(II)-Catalyzed Aerobic Biomimetic Oxidation of N-Heterocycles. Chemistry 2021; 27:13725-13729. [PMID: 34324754 PMCID: PMC8518507 DOI: 10.1002/chem.202102483] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Indexed: 12/29/2022]
Abstract
Herein, an iron(II)-catalyzed biomimetic oxidation of N-heterocycles under aerobic conditions is described. The dehydrogenation process, involving several electron-transfer steps, is inspired by oxidations occurring in the respiratory chain. An environmentally friendly and inexpensive iron catalyst together with a hydroquinone/cobalt Schiff base hybrid catalyst as electron-transfer mediator were used for the substrate-selective dehydrogenation reaction of various N-heterocycles. The method shows a broad substrate scope and delivers important heterocycles in good-to-excellent yields.
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Affiliation(s)
- Srimanta Manna
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, 10691, Stockholm, Sweden
| | - Wei-Jun Kong
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, 10691, Stockholm, Sweden
| | - Jan-E Bäckvall
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, 10691, Stockholm, Sweden
- Department of Natural Sciences, Mid Sweden University, 85170, Sundsvall, Sweden
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13
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Maaß SC, de Jong J, van Maanen L, van Rijn H. Conceptually plausible Bayesian inference in interval timing. ROYAL SOCIETY OPEN SCIENCE 2021; 8:201844. [PMID: 34457319 PMCID: PMC8371368 DOI: 10.1098/rsos.201844] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 07/20/2021] [Indexed: 05/12/2023]
Abstract
In a world that is uncertain and noisy, perception makes use of optimization procedures that rely on the statistical properties of previous experiences. A well-known example of this phenomenon is the central tendency effect observed in many psychophysical modalities. For example, in interval timing tasks, previous experiences influence the current percept, pulling behavioural responses towards the mean. In Bayesian observer models, these previous experiences are typically modelled by unimodal statistical distributions, referred to as the prior. Here, we critically assess the validity of the assumptions underlying these models and propose a model that allows for more flexible, yet conceptually more plausible, modelling of empirical distributions. By representing previous experiences as a mixture of lognormal distributions, this model can be parametrized to mimic different unimodal distributions and thus extends previous instantiations of Bayesian observer models. We fit the mixture lognormal model to published interval timing data of healthy young adults and a clinical population of aged mild cognitive impairment patients and age-matched controls, and demonstrate that this model better explains behavioural data and provides new insights into the mechanisms that underlie the behaviour of a memory-affected clinical population.
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Affiliation(s)
- Sarah C. Maaß
- Department of Experimental Psychology, University of Groningen, Grote Kruisstraat 2/1, 9712TS Groningen, The Netherlands
- Behavioral and Cognitive Neurosciences, University of Groningen, Grote Kruisstraat 2/1, 9712TS Groningen, The Netherlands
- Aging and Cognition Research Group, German Center for Neurodegenerative Diseases (DZNE), Leipziger Straße 44, 39120 Magdeburg, Germany
| | - Joost de Jong
- Department of Experimental Psychology, University of Groningen, Grote Kruisstraat 2/1, 9712TS Groningen, The Netherlands
- Behavioral and Cognitive Neurosciences, University of Groningen, Grote Kruisstraat 2/1, 9712TS Groningen, The Netherlands
| | - Leendert van Maanen
- Department of Experimental Psychology, Utrecht University, Heidelberglaan 1, 3584 CS Utrecht, The Netherlands
| | - Hedderik van Rijn
- Department of Experimental Psychology, University of Groningen, Grote Kruisstraat 2/1, 9712TS Groningen, The Netherlands
- Behavioral and Cognitive Neurosciences, University of Groningen, Grote Kruisstraat 2/1, 9712TS Groningen, The Netherlands
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14
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Han C, Kim HJ, Lee JS, Sakakura Y, Hagiwara A. Species-specific effects of iron on temperate and tropical marine rotifers in reproduction, lipid and ROS metabolisms. CHEMOSPHERE 2021; 277:130317. [PMID: 33780671 DOI: 10.1016/j.chemosphere.2021.130317] [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: 01/13/2021] [Revised: 03/07/2021] [Accepted: 03/14/2021] [Indexed: 06/12/2023]
Abstract
Two euryhaline rotifers, the temperate species Brachionus plicatilis and tropical species Brachionus rotundiformis, were used to investigate the effects of iron (FeSO4·7H2O), an essential trace metal, on reproductive patterns and lifetables, including the metabolism of lipid and reactive oxygen species (ROS). B. plicatilis was more sensitive to iron with regard to sexual reproduction. While iron had no significant effect on the population growth at 0-48 μg/mL, it caused a decrease in the resting egg production. B. plicatilis exposed to 6 and 12 μg/mL of iron showed an increase in the intracellular ROS levels and a decrease in the neutral lipid content in sexual organs, accompanied by downregulation of antioxidant components CuZnSOD and two cytochromes (CYP clan 2&3). These patterns suggested that iron-induced oxidative stress was not neutralized by its antioxidant defense system, thus negatively affecting the fecundity of fertilized mictic females. However, B. rotundiformis showed a dose-dependent increase in population growth with extended lifespan and positive sexual reproduction in response to 0-24 μg/mL iron. Furthermore, compared to Fe-exposed B. plicatilis, B. rotundiformis showed better antioxidant mechanism, whereas genes involved in lipid synthesis (citrate lyase, mitochondrial CYP) and reproduction (vasa, sirtuin-2) were significantly upregulated compared to the control, implying that B. rotundiformis was likely to have higher resilience in response to iron-induced oxidative stress. These findings suggest that iron is likely to cause interspecific interactions in the B. plicatilis species complex, whereas the tropical species B. rotundiformis may have evolved an effective defense mechanism against iron-induced stress.
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Affiliation(s)
- Chengyan Han
- Graduate School of Fisheries and Environmental Sciences, Nagasaki University, Bunkyo 1-14, Nagasaki, 852-8521, Japan.
| | - Hee-Jin Kim
- Graduate School of Fisheries and Environmental Sciences, Nagasaki University, Bunkyo 1-14, Nagasaki, 852-8521, Japan.
| | - Jae-Seong Lee
- Department of Biological Sciences, College of Science, Sungkyunkwan University, Suwon, 16419, South Korea.
| | - Yoshitaka Sakakura
- Graduate School of Fisheries and Environmental Sciences, Nagasaki University, Bunkyo 1-14, Nagasaki, 852-8521, Japan; Organization for Marine Science and Technology, Nagasaki University, Bunkyo 1-14, Nagasaki, 852-8521, Japan.
| | - Atsushi Hagiwara
- Graduate School of Fisheries and Environmental Sciences, Nagasaki University, Bunkyo 1-14, Nagasaki, 852-8521, Japan; Organization for Marine Science and Technology, Nagasaki University, Bunkyo 1-14, Nagasaki, 852-8521, Japan.
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15
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Liu J, Guðmundsson A, Bäckvall J. Efficient Aerobic Oxidation of Organic Molecules by Multistep Electron Transfer. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202012707] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Jie Liu
- State Key Laboratory of Chemo/Biosensing and Chemometrics College of Chemistry and Chemical Engineering Hunan University 410082 Changsha China
- Department of Organic Chemistry Arrhenius Laboratory Stockholm University SE-10691 Stockholm Sweden
| | - Arnar Guðmundsson
- Department of Organic Chemistry Arrhenius Laboratory Stockholm University SE-10691 Stockholm Sweden
| | - Jan‐E. Bäckvall
- Department of Organic Chemistry Arrhenius Laboratory Stockholm University SE-10691 Stockholm Sweden
- Department of Natural Sciences Mid Sweden University Holmgatan 10 SE-85170 Sundsvall Sweden
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16
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Liu J, Guðmundsson A, Bäckvall J. Efficient Aerobic Oxidation of Organic Molecules by Multistep Electron Transfer. Angew Chem Int Ed Engl 2021; 60:15686-15704. [PMID: 33368909 PMCID: PMC9545650 DOI: 10.1002/anie.202012707] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Indexed: 12/17/2022]
Abstract
This Minireview presents recent important homogenous aerobic oxidative reactions which are assisted by electron transfer mediators (ETMs). Compared with direct oxidation by molecular oxygen (O2 ), the use of a coupled catalyst system with ETMs leads to a lower overall energy barrier via stepwise electron transfer. This cooperative catalytic process significantly facilitates the transport of electrons from the reduced form of the substrate-selective redox catalyst (SSRCred ) to O2 , thereby increasing the efficiency of the aerobic oxidation. In this Minireview, we have summarized the advances accomplished in recent years in transition-metal-catalyzed as well as metal-free aerobic oxidations of organic molecules in the presence of ETMs. In addition, the recent progress of photochemical and electrochemical oxidative functionalization using ETMs and O2 as the terminal oxidant is also highlighted. Furthermore, the mechanisms of these transformations are showcased.
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Affiliation(s)
- Jie Liu
- State Key Laboratory of Chemo/Biosensing and ChemometricsCollege of Chemistry and Chemical EngineeringHunan University410082ChangshaChina
- Department of Organic ChemistryArrhenius LaboratoryStockholm UniversitySE-10691StockholmSweden
| | - Arnar Guðmundsson
- Department of Organic ChemistryArrhenius LaboratoryStockholm UniversitySE-10691StockholmSweden
| | - Jan‐E. Bäckvall
- Department of Organic ChemistryArrhenius LaboratoryStockholm UniversitySE-10691StockholmSweden
- Department of Natural SciencesMid Sweden UniversityHolmgatan 10SE-85170SundsvallSweden
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17
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Guðmundsson A, Manna S, Bäckvall J. Iron(II)‐Catalyzed Aerobic Biomimetic Oxidation of Amines using a Hybrid Hydroquinone/Cobalt Catalyst as Electron Transfer Mediator. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202102681] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Arnar Guðmundsson
- Department of Organic Chemistry Arrhenius Laboratory Stockholm University 10691 Stockholm Sweden
| | - Srimanta Manna
- Department of Organic Chemistry Arrhenius Laboratory Stockholm University 10691 Stockholm Sweden
| | - Jan‐E. Bäckvall
- Department of Organic Chemistry Arrhenius Laboratory Stockholm University 10691 Stockholm Sweden
- Department of Natural Sciences Mid Sweden University 85170 Sundsvall Sweden
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18
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Guðmundsson A, Manna S, Bäckvall J. Iron(II)-Catalyzed Aerobic Biomimetic Oxidation of Amines using a Hybrid Hydroquinone/Cobalt Catalyst as Electron Transfer Mediator. Angew Chem Int Ed Engl 2021; 60:11819-11823. [PMID: 33725364 PMCID: PMC8252094 DOI: 10.1002/anie.202102681] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Indexed: 11/30/2022]
Abstract
Herein we report the first FeII -catalyzed aerobic biomimetic oxidation of amines. This oxidation reaction involves several electron transfer steps and is inspired by biological oxidation in the respiratory chain. The electron transfer from the amine to molecular oxygen is aided by two coupled catalytic redox systems, which lower the energy barrier and improve the selectivity of the oxidation reaction. An iron hydrogen transfer complex was utilized as the substrate-selective dehydrogenation catalyst along with a bifunctional hydroquinone/cobalt Schiff base complex as a hybrid electron transfer mediator. Various primary and secondary amines were oxidized in air to their corresponding aldimines or ketimines in good to excellent yield.
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Affiliation(s)
- Arnar Guðmundsson
- Department of Organic ChemistryArrhenius LaboratoryStockholm University10691StockholmSweden
| | - Srimanta Manna
- Department of Organic ChemistryArrhenius LaboratoryStockholm University10691StockholmSweden
| | - Jan‐E. Bäckvall
- Department of Organic ChemistryArrhenius LaboratoryStockholm University10691StockholmSweden
- Department of Natural SciencesMid Sweden University85170SundsvallSweden
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19
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Osella S. Artificial Photosynthesis: Is Computation Ready for the Challenge Ahead? NANOMATERIALS 2021; 11:nano11020299. [PMID: 33498961 PMCID: PMC7911014 DOI: 10.3390/nano11020299] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 01/19/2021] [Accepted: 01/20/2021] [Indexed: 12/13/2022]
Abstract
A tremendous effort is currently devoted to the generation of novel hybrid materials with enhanced electronic properties for the creation of artificial photosynthetic systems. This compelling and challenging problem is well-defined from an experimental point of view, as the design of such materials relies on combining organic materials or metals with biological systems like light harvesting and redox-active proteins. Such hybrid systems can be used, e.g., as bio-sensors, bio-fuel cells, biohybrid photoelectrochemical cells, and nanostructured photoelectronic devices. Despite these efforts, the main bottleneck is the formation of efficient interfaces between the biological and the organic/metal counterparts for efficient electron transfer (ET). It is within this aspect that computation can make the difference and improve the current understanding of the mechanisms underneath the interface formation and the charge transfer efficiency. Yet, the systems considered (i.e., light harvesting protein, self-assembly monolayer and surface assembly) are more and more complex, reaching (and often passing) the limit of current computation power. In this review, recent developments in computational methods for studying complex interfaces for artificial photosynthesis will be provided and selected cases discussed, to assess the inherent ability of computation to leave a mark in this field of research.
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Affiliation(s)
- Silvio Osella
- Chemical and Biological Systems Simulation Lab, Center of New Technologies, University of Warsaw, Banacha 2C, 02-097 Warsaw, Poland
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20
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Tonai S, Kawabata A, Nakanishi T, Lee JY, Okamoto A, Shimada M, Yamashita Y. Iron deficiency induces female infertile in order to failure of follicular development in mice. J Reprod Dev 2020; 66:475-483. [PMID: 32713881 PMCID: PMC7593635 DOI: 10.1262/jrd.2020-074] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Iron is important for many cellular functions, including ATP synthesis and cell proliferation. Insufficient of iron in the diet causes iron deficiency anemia
(IDA), which often occurs in people living in the world. Since 50% of women with IDA show amenorrhea, the relationship of between iron deficiency and
reproductive function was assessed using mice fed a low Fe diet (LFD). The estrous cycle in the LFD mice was blocked at diestrus, which impair follicle
development, and fertility. Further, even LFD mice were injected with exogenous pregnant mare serum gonadotropin (PMSG), follicular development was ceased at
the secondary follicle stage, and preovulatory follicles were not observed. Amount of ATP decreased in the ovary of the LFD mice, and expression of follicle
development markers (Fshr, Cyp19a1, Ccnd2) and estradiol-17β (E2) was low level compared to levels mice fed a
normal diet. Feeding a normal diet with sufficient iron to the LFD mice for an additional 3 weeks completely reversed absence the effects of iron insufficient
on the estrous cycle and infertility. Thus, iron restriction depresses ovary functions, especially follicular development from secondary follicle to antral
follicles and infertility. These effects are fully reversible by supplementation of a normal diet containing iron.
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Affiliation(s)
- Shingo Tonai
- Graduate School of Comprehensive Scientific Research, Prefectural University of Hiroshima, Hiroshima 727-0023, Japan
| | - Akane Kawabata
- Graduate School of Comprehensive Scientific Research, Prefectural University of Hiroshima, Hiroshima 727-0023, Japan
| | - Tomoya Nakanishi
- Graduate School of Comprehensive Scientific Research, Prefectural University of Hiroshima, Hiroshima 727-0023, Japan
| | - Joo Yeon Lee
- Graduate School of Comprehensive Scientific Research, Prefectural University of Hiroshima, Hiroshima 727-0023, Japan
| | - Asako Okamoto
- Graduate School of Comprehensive Scientific Research, Prefectural University of Hiroshima, Hiroshima 727-0023, Japan.,Department of Comparative Animal Science, College of Life Science, Kurashiki University of Science and the Arts, Okayama 712-8505, Japan
| | - Masayuki Shimada
- Graduate School of Biosphere Science, Hiroshima University, Hiroshima 739-8528, Japan
| | - Yasuhisa Yamashita
- Graduate School of Comprehensive Scientific Research, Prefectural University of Hiroshima, Hiroshima 727-0023, Japan
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21
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Guðmundsson A, Schlipköter KE, Bäckvall J. Iron(II)-Catalyzed Biomimetic Aerobic Oxidation of Alcohols. Angew Chem Int Ed Engl 2020; 59:5403-5406. [PMID: 31999013 PMCID: PMC7154773 DOI: 10.1002/anie.202000054] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Indexed: 12/16/2022]
Abstract
We report the first FeII -catalyzed biomimetic aerobic oxidation of alcohols. The principle of this oxidation, which involves several electron-transfer steps, is reminiscent of biological oxidation in the respiratory chain. The electron transfer from the alcohol to molecular oxygen occurs with the aid of three coupled catalytic redox systems, leading to a low-energy pathway. An iron transfer-hydrogenation complex was utilized as a substrate-selective dehydrogenation catalyst, along with an electron-rich quinone and an oxygen-activating Co(salen)-type complex as electron-transfer mediators. Various primary and secondary alcohols were oxidized in air to the corresponding aldehydes or ketones with this method in good to excellent yields.
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Affiliation(s)
- Arnar Guðmundsson
- Department of Organic ChemistryArrhenius LaboratoryStockholm University10691StockholmSweden
| | - Kim Elisabeth Schlipköter
- Department of Organic ChemistryArrhenius LaboratoryStockholm University10691StockholmSweden
- Current address: Institute of Technical BiocatalysisHamburg University of Technology TUHH21071HamburgGermany
| | - Jan‐E. Bäckvall
- Department of Organic ChemistryArrhenius LaboratoryStockholm University10691StockholmSweden
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22
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Guðmundsson A, Schlipköter KE, Bäckvall J. Iron(II)‐Catalyzed Biomimetic Aerobic Oxidation of Alcohols. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202000054] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Arnar Guðmundsson
- Department of Organic ChemistryArrhenius Laboratory Stockholm University 10691 Stockholm Sweden
| | - Kim Elisabeth Schlipköter
- Department of Organic ChemistryArrhenius Laboratory Stockholm University 10691 Stockholm Sweden
- Current address: Institute of Technical BiocatalysisHamburg University of Technology TUHH 21071 Hamburg Germany
| | - Jan‐E. Bäckvall
- Department of Organic ChemistryArrhenius Laboratory Stockholm University 10691 Stockholm Sweden
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23
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Bhattacharya A, Pulliam D, Liu Y, Salmon AB. Mitochondrial-targeted methionine sulfoxide reductase overexpression increases the production of oxidative stress in mitochondria from skeletal muscle. ACTA ACUST UNITED AC 2020; 2:45-51. [PMID: 33829213 PMCID: PMC8023689 DOI: 10.31491/apt.2020.03.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Objective: Mitochondrial dysfunction comprises part of the etiology of myriad health issues, particularly those that occur with advancing age. Methionine sulfoxide reductase A (MsrA) is a ubiquitous protein oxidation repair enzyme that specifically and catalytically reduces a specific epimer of oxidized methionine: methionine sulfoxide. In this study, we tested the ways in which mitochondrial bioenergetic functions are affected by increasing MsrA expression in different cellular compartments. Methods: In this study, we tested the function of isolated mitochondria, including free radical generation, ATP production, and respiration, from the skeletal muscle of two lines of transgenic mice with increased MsrA expression: mitochondria-targeted MsrA overexpression or cytosol-targeted MsrA overexpression. Results: Surprisingly, in the samples from mice with mitochondrial-targeted MsrA overexpression, we found dramatically increased free radical production though no specific defect in respiration, ATP production, or membrane potential. Among the electron transport chain complexes, we found the activity of complex I was specifically reduced in mitochondrial MsrA transgenic mice. In mice with cytosolic-targeted MsrA overexpression, we found no significant alteration made to any of these parameters of mitochondrial energetics. Conclusions: There is also a growing amount of evidence that MsrA is a functional requirement for sustaining optimal mitochondrial respiration and free radical generation. MsrA is also known to play a partial role in maintaining normal protein homeostasis by specifically repairing oxidized proteins. Our studies highlight a potential novel role for MsrA in regulating the activity of mitochondrial function through its interaction with the mitochondrial proteome.
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Affiliation(s)
- Arunabh Bhattacharya
- The Sam and Ann Barshop Institute for Longevity and Aging Studies, UT Health San Antonio, San Antonio TX, USA.,Department of Cellular & Structural Anatomy, UT Health San Antonio, San Antonio TX, USA.,Department of Clinically Applied Science Education, University of the Incarnate Word School of Osteopathic Medicine, San Antonio, TX, USA
| | - Daniel Pulliam
- The Sam and Ann Barshop Institute for Longevity and Aging Studies, UT Health San Antonio, San Antonio TX, USA
| | - Yuhong Liu
- The Sam and Ann Barshop Institute for Longevity and Aging Studies, UT Health San Antonio, San Antonio TX, USA
| | - Adam B Salmon
- The Sam and Ann Barshop Institute for Longevity and Aging Studies, UT Health San Antonio, San Antonio TX, USA.,Department of Molecular Medicine, UT Health San Antonio, San Antonio TX, USA.,Geriatric Research, Education and Clinical Center, South Texas Veterans Healthcare System, San Antonio TX, USA
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24
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mTOR-Mediated Antioxidant Activation in Solid Tumor Radioresistance. JOURNAL OF ONCOLOGY 2019; 2019:5956867. [PMID: 31929797 PMCID: PMC6942807 DOI: 10.1155/2019/5956867] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 11/20/2019] [Accepted: 11/30/2019] [Indexed: 12/27/2022]
Abstract
Radiotherapy is widely used for the treatment of cancer patients, but tumor radioresistance presents serious therapy challenges. Tumor radioresistance is closely related to high levels of mTOR signaling in tumor tissues. Therefore, targeting the mTOR pathway might be a strategy to promote solid tumor sensitivity to ionizing radiation. Radioresistance is associated with enhanced antioxidant mechanisms in cancer cells. Therefore, examination of the relationship between mTOR signaling and antioxidant mechanism-linked radioresistance is required for effective radiotherapy. In particular, the effect of mTOR signaling on antioxidant glutathione induction by the Keap1-NRF2-xCT pathway is described in this review. This review is expected to assist in the identification of therapeutic adjuvants to increase the efficacy of radiotherapy.
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25
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Martin DR, Dinpajooh M, Matyushov DV. Polarizability of the Active Site in Enzymatic Catalysis: Cytochrome c. J Phys Chem B 2019; 123:10691-10699. [DOI: 10.1021/acs.jpcb.9b09236] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Mohammadhasan Dinpajooh
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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26
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Kaila VRI. Long-range proton-coupled electron transfer in biological energy conversion: towards mechanistic understanding of respiratory complex I. J R Soc Interface 2019; 15:rsif.2017.0916. [PMID: 29643224 PMCID: PMC5938582 DOI: 10.1098/rsif.2017.0916] [Citation(s) in RCA: 97] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 03/13/2018] [Indexed: 12/20/2022] Open
Abstract
Biological energy conversion is driven by efficient enzymes that capture, store and transfer protons and electrons across large distances. Recent advances in structural biology have provided atomic-scale blueprints of these types of remarkable molecular machinery, which together with biochemical, biophysical and computational experiments allow us to derive detailed energy transduction mechanisms for the first time. Here, I present one of the most intricate and least understood types of biological energy conversion machinery, the respiratory complex I, and how its redox-driven proton-pump catalyses charge transfer across approximately 300 Å distances. After discussing the functional elements of complex I, a putative mechanistic model for its action-at-a-distance effect is presented, and functional parallels are drawn to other redox- and light-driven ion pumps.
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Affiliation(s)
- Ville R I Kaila
- Department of Chemistry, Technische Universität München, Lichtenbergstr. 4, Garching, Germany
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27
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Bennett JP. Medical hypothesis: Neurodegenerative diseases arise from oxidative damage to electron tunneling proteins in mitochondria. Med Hypotheses 2019; 127:1-4. [PMID: 31088629 DOI: 10.1016/j.mehy.2019.03.034] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Revised: 03/26/2019] [Accepted: 03/27/2019] [Indexed: 12/15/2022]
Abstract
Mitochondria likely arose from serial endosymbiosis by early eukaryotic cells and control electron flow to molecular oxygen to facilitate energy transformation. Mitochondria translate between the quantum and macroscopic worlds and utilize quantum tunneling of electrons to reduce activation energy barriers to electron flow. Electron tunneling has been extensively characterized in Complex I of the electron transport chain. Age-related increases in oxidative damage to these electron tunneling systems may account for decreased energy storage found in aged and neurodegenerative disease tissues, such as those from sufferers of amyotrophic lateral sclerosis (ALS), Alzheimer's disease (AD) and Parkinson's disease (PD). This hypothesis is testable. If correct, this hypothesis supports pre-symptomatic, mitochondrially-directed oxygen free radical scavenging therapies.
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Affiliation(s)
- James P Bennett
- Neurodegeneration Therapeutics, Inc., 3050A Berkmar Drive, Charlottesville, VA 22901-3450, United States.
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28
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Le Poul N, Colasson B, Thiabaud G, Dit Fouque DJ, Iacobucci C, Memboeuf A, Douziech B, Řezáč J, Prangé T, de la Lande A, Reinaud O, Le Mest Y. Gating the electron transfer at a monocopper centre through the supramolecular coordination of water molecules within a protein chamber mimic. Chem Sci 2018; 9:8282-8290. [PMID: 30542577 PMCID: PMC6240898 DOI: 10.1039/c8sc03124j] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Accepted: 08/29/2018] [Indexed: 11/21/2022] Open
Abstract
Functionality of enzymes is strongly related to water dynamic processes.
Functionality of enzymes is strongly related to water dynamic processes. The control of the redox potential for metallo-enzymes is intimately linked to the mediation of water molecules in the first and second coordination spheres. Here, we report a unique example of supramolecular control of the redox properties of a biomimetic monocopper complex by water molecules. It is shown that the copper complex based on a calix[6]arene covalently capped with a tetradentate [tris(2-methylpyridyl)amine] (tmpa) core, embedding the metal ion in a hydrophobic cavity, can exist in three different states. The first system displays a totally irreversible redox behaviour. It corresponds to the reduction of the 5-coordinate mono-aqua-CuII complex, which is the thermodynamic species in the +II state. The second system is detected at a high redox potential. It is ascribed to an “empty cavity” or “water-free” state, where the CuI ion sits in a 4-coordinate trigonal environment provided by the tmpa cap. This complex is the thermodynamic species in the +I state under “dry conditions”. Surprisingly, a third redox system appears as the water concentration is increased. Under water-saturation conditions, it displays a pseudo-reversible behaviour at a low scan rate at the mid-point from the water-free and aqua species. This third system is not observed with the Cu-tmpa complex deprived of a cavity. In the calix[6]cavity environment, it is ascribed to a species where a pair of water molecules is hosted by the calixarene cavity. A molecular mechanism for the CuII/CuI redox process with an interplay of (H2O)x (x = 0, 1, 2) hosting is proposed on the basis of computational studies. Such an unusual behaviour is ascribed to the unexpected stabilization of the CuI state by inclusion of the pair of water molecules. This phenomenon strongly evidences the drastic influence of the interaction between water molecules and a hydrophobic cavity on controlling the thermodynamics and kinetics of the CuII/CuI electron transfer process.
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Affiliation(s)
- Nicolas Le Poul
- Laboratoire de Chimie , Electrochimie Moléculaires et Chimie Analytique , UMR CNRS 6521 , Université de Brest , 29238 Brest , France . ; ; ; ; ;
| | - Benoit Colasson
- Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques , UMR CNRS 8601 , Université Paris Descartes , 75006 Paris , France . ;
| | - Grégory Thiabaud
- Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques , UMR CNRS 8601 , Université Paris Descartes , 75006 Paris , France . ;
| | - Dany Jeanne Dit Fouque
- Laboratoire de Chimie , Electrochimie Moléculaires et Chimie Analytique , UMR CNRS 6521 , Université de Brest , 29238 Brest , France . ; ; ; ; ;
| | - Claudio Iacobucci
- Laboratoire de Chimie , Electrochimie Moléculaires et Chimie Analytique , UMR CNRS 6521 , Université de Brest , 29238 Brest , France . ; ; ; ; ;
| | - Antony Memboeuf
- Laboratoire de Chimie , Electrochimie Moléculaires et Chimie Analytique , UMR CNRS 6521 , Université de Brest , 29238 Brest , France . ; ; ; ; ;
| | - Bénédicte Douziech
- Laboratoire de Chimie , Electrochimie Moléculaires et Chimie Analytique , UMR CNRS 6521 , Université de Brest , 29238 Brest , France . ; ; ; ; ;
| | - Jan Řezáč
- Institute of Organic Chemistry and Biochemistry , Academy of Sciences of the Czech Republic , Flemingovonám. 2 , 166 10 Prague 6 , Czech Republic .
| | - Thierry Prangé
- Laboratoire de Cristallographie et de Résonance Magnétique Nucléaire , Biologiques (CNRS UMR 8015) , Université Paris Descartes , 4, Avenue de l'Observatoire , 75006 Paris , France .
| | - Aurélien de la Lande
- Laboratoire de Chimie Physique , UMR CNRS 8000 , Université Paris Sud , 91405 Orsay , France .
| | - Olivia Reinaud
- Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques , UMR CNRS 8601 , Université Paris Descartes , 75006 Paris , France . ;
| | - Yves Le Mest
- Laboratoire de Chimie , Electrochimie Moléculaires et Chimie Analytique , UMR CNRS 6521 , Université de Brest , 29238 Brest , France . ; ; ; ; ;
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29
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Waskasi MM, Martin DR, Matyushov DV. Wetting of the Protein Active Site Leads to Non-Marcusian Reaction Kinetics. J Phys Chem B 2018; 122:10490-10495. [PMID: 30365331 DOI: 10.1021/acs.jpcb.8b10376] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Enzymes exist in continuously fluctuating water bath dramatically affecting their function. Water not only forms the solvation shell but also penetrates into the protein interior. Changing the wetting pattern of the protein's active site in response to altering redox state initiates a highly nonlinear structural change and non-Gaussian electrostatic fluctuations at the active site. The free-energy surfaces of electron transfer are highly nonparabolic (non-Marcusian), as shown by atomistic molecular dynamics simulations of hydrated ferredoxin protein and by an analytical model in agreement with simulations. The reorganization energy of electron transfer passes through a spike marking equal probabilities of the wet and dry states of the active site. The activation thermodynamics affected by wetting leads to a non-Arrhenius, passing through a maximum, plot for the reaction rate vs the inverse temperature.
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Affiliation(s)
- Morteza M Waskasi
- School of Molecular Sciences , Arizona State University , P.O. Box 871604, Tempe , Arizona 85287-1604 , United States
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Links Between Iron and Lipids: Implications in Some Major Human Diseases. Pharmaceuticals (Basel) 2018; 11:ph11040113. [PMID: 30360386 PMCID: PMC6315991 DOI: 10.3390/ph11040113] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 10/18/2018] [Accepted: 10/19/2018] [Indexed: 12/30/2022] Open
Abstract
Maintenance of iron homeostasis is critical to cellular health as both its excess and insufficiency are detrimental. Likewise, lipids, which are essential components of cellular membranes and signaling mediators, must also be tightly regulated to hinder disease progression. Recent research, using a myriad of model organisms, as well as data from clinical studies, has revealed links between these two metabolic pathways, but the mechanisms behind these interactions and the role these have in the progression of human diseases remains unclear. In this review, we summarize literature describing cross-talk between iron and lipid pathways, including alterations in cholesterol, sphingolipid, and lipid droplet metabolism in response to changes in iron levels. We discuss human diseases correlating with both iron and lipid alterations, including neurodegenerative disorders, and the available evidence regarding the potential mechanisms underlying how iron may promote disease pathogenesis. Finally, we review research regarding iron reduction techniques and their therapeutic potential in treating patients with these debilitating conditions. We propose that iron-mediated alterations in lipid metabolic pathways are involved in the progression of these diseases, but further research is direly needed to elucidate the mechanisms involved.
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Koo J, Swartz JR. System analysis and improved [FeFe] hydrogenase O2 tolerance suggest feasibility for photosynthetic H2 production. Metab Eng 2018; 49:21-27. [DOI: 10.1016/j.ymben.2018.04.024] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 04/27/2018] [Accepted: 04/29/2018] [Indexed: 11/16/2022]
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Matyushov DV. Fluctuation relations, effective temperature, and ageing of enzymes: The case of protein electron transfer. J Mol Liq 2018. [DOI: 10.1016/j.molliq.2018.06.087] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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A modeling and simulation perspective on the mechanism and function of respiratory complex I. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:510-523. [DOI: 10.1016/j.bbabio.2018.04.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 04/03/2018] [Accepted: 04/10/2018] [Indexed: 12/12/2022]
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Seyedi S, Matyushov DV. Termination of Biological Function at Low Temperatures: Glass or Structural Transition? J Phys Chem Lett 2018; 9:2359-2366. [PMID: 29669418 DOI: 10.1021/acs.jpclett.8b00537] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Energy of life is produced by electron transfer in energy chains of respiration or photosynthesis. A small input of free energy available to biology puts significant restrictions on how much free energy can be lost in each electron-transfer reaction. We advocate the view that breaking ergodicity, leading to violation of the fluctuation-dissipation theorem (FDT), is how proteins achieve high reaction rates without sacrificing the reaction free energy. Here we show that a significant level of nonergodicity, represented by a large extent of the configurational temperature over the kinetic temperature, is maintained in the entire physiological range for the cytochrome c electron transfer protein. The protein returns to the state consistent with the FDT below the crossover temperature close to the temperature of the protein glass transition. This crossover leads to a sharp increase in the activation barrier of electron transfer and is displayed by a kink in the Arrhenius plot for the reaction rate constant.
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Affiliation(s)
- Salman Seyedi
- Department of Physics and School of Molecular Sciences , Arizona State University , P.O. Box 871504, Tempe , Arizona 85287-1504 , United States
| | - Dmitry V Matyushov
- Department of Physics and School of Molecular Sciences , Arizona State University , P.O. Box 871504, Tempe , Arizona 85287-1504 , United States
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Tsai CL, Tainer JA. Robust Production, Crystallization, Structure Determination, and Analysis of [Fe-S] Proteins: Uncovering Control of Electron Shuttling and Gating in the Respiratory Metabolism of Molybdopterin Guanine Dinucleotide Enzymes. Methods Enzymol 2017; 599:157-196. [PMID: 29746239 DOI: 10.1016/bs.mie.2017.11.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
[Fe-S] clusters are essential cofactors in all domains of life. They play many biological roles due to their unique abilities for electron transfer and conformational control. Yet, producing and analyzing Fe-S proteins can be difficult and even misleading if not done anaerobically. Due to unique redox properties of [Fe-S] clusters and their oxygen sensitivity, they pose multiple challenges and can lose enzymatic activity or cause their component proteins to be structurally disordered due to [Fe-S] cluster oxidation and loss in air. Here we highlight tested protocols and strategies enabling efficient and stable [Fe-S] protein production, purification, crystallization, X-ray diffraction data collection, and structure determination. From multiple high-resolution anaerobic crystal structures, we furthermore analyze exemplary data defining [Fe-S] clusters, substrate entry, and product exit for the functional oxidation states of type II molybdo-bis(molybdopterin guanine dinucleotide) (Mo-bisMGD) enzymes. Notably, these enzymes perform electron shuttling between quinone pools and specific substrates to catalyze respiratory metabolism. The identified structure-activity relationships for this enzyme class have broad implications germane to perchlorate environments on Earth and Mars extending to an alternative mechanism underlying metabolic origins for the evolution of the oxygen atmosphere. Integrated structural analyses of type II Mo-bisMGD enzymes unveil novel distinctive shared molecular mechanisms for dynamic control of substrate entry and product release gated by hydrophobic residues. Collective findings support a prototypic model for type II Mo-bisMGD enzymes including insights for a fundamental molecular mechanistic understanding of selectivity and regulation by a conformationally gated channel with general implications for [Fe-S] cluster respiratory enzymes.
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Affiliation(s)
- Chi-Lin Tsai
- The University of Texas M. D. Anderson Cancer Center, Houston, TX, United States
| | - John A Tainer
- The University of Texas M. D. Anderson Cancer Center, Houston, TX, United States; Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA, United States.
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