1
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Deviers J, Cailliez F, de la Lande A, Kattnig DR. Avian cryptochrome 4 binds superoxide. Comput Struct Biotechnol J 2024; 26:11-21. [PMID: 38204818 PMCID: PMC10776438 DOI: 10.1016/j.csbj.2023.12.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 12/06/2023] [Accepted: 12/12/2023] [Indexed: 01/12/2024] Open
Abstract
Flavin-binding cryptochromes are blue-light sensitive photoreceptors that have been implicated with magnetoreception in some species. The photocycle involves an intra-protein photo-reduction of the flavin cofactor, generating a magnetosensitive radical pair, and its subsequent re-oxidation. Superoxide (O2 • - ) is generated in the re-oxidation with molecular oxygen. The resulting O2 • - -containing radical pairs have also been hypothesised to underpin various magnetosensitive traits, but due to fast spin relaxation when tumbling in solution would require immobilisation. We here describe our insights in the binding of superoxide to cryptochrome 4 from C. livia based on extensive all-atom molecular dynamics studies and density-functional theory calculations. The positively charged "crypt" region that leads to the flavin binding pocket transiently binds O2 • - at 5 flexible binding sites centred on arginine residues. Typical binding times amounted to tens of nanoseconds, but exceptional binding events extended to several hundreds of nanoseconds and slowed the rotational diffusion, thereby realising rotational correlation times as large as 1 ns. The binding sites are particularly efficient in scavenging superoxide escaping from a putative generation site close to the flavin-cofactor, possibly implying a functional relevance. We discuss our findings in view of a potential magnetosensitivity of biological flavin semiquinone/superoxide radical pairs.
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Affiliation(s)
- Jean Deviers
- Living Systems Institute and Department of Physics, University of Exeter, Stocker Road, Exeter, Devon, EX4 4QD, United Kingdom
- Institut de Chimie Physique, CNRS UMR 8000, Université Paris-Saclay, 91405 Orsay, France
| | - Fabien Cailliez
- Institut de Chimie Physique, CNRS UMR 8000, Université Paris-Saclay, 91405 Orsay, France
| | - Aurélien de la Lande
- Institut de Chimie Physique, CNRS UMR 8000, Université Paris-Saclay, 91405 Orsay, France
| | - Daniel R. Kattnig
- Living Systems Institute and Department of Physics, University of Exeter, Stocker Road, Exeter, Devon, EX4 4QD, United Kingdom
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2
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Kretschmer K, Frederiksen A, Reinholdt P, Kongsted J, Solov'yov IA. Understanding the Red Shift in the Absorption Spectrum of the FAD Cofactor in ClCry4 Protein. J Phys Chem B 2024. [PMID: 38805723 DOI: 10.1021/acs.jpcb.4c00710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2024]
Abstract
It is still a puzzle that has not been entirely solved how migratory birds utilize the Earth's magnetic field for biannual migration. The most consistent explanation thus far is rooted in the modulation of the biological function of the cryptochrome 4 (Cry4) protein by an external magnetic field. This phenomenon is closely linked with the flavin adenine dinucleotide (FAD) cofactor that is noncovalently bound in the protein. Cry4 is activated by blue light, which is absorbed by the FAD cofactor. Subsequent electron and proton transfers trigger radical pair formation in the protein, which is sensitive to the external magnetic field. An important long-lasting redox state of the FAD cofactor is the signaling (FADH•) state, which is present after the transient electron transfer steps have been completed. Recent experimental efforts succeeded in crystallizing the Cry4 protein from Columbia livia (ClCry4) with all of the important residues needed for protein photoreduction. This specific crystallization of Cry4 protein so far is the only avian cryptochrome crystal structure available, which, however, has great similarity to the Cry4 proteins of night migratory birds. The previous experimental studies of the ClCry4 protein included the absorption properties of the protein in its different redox states. The absorption spectrum of the FADH• state demonstrated a peculiar red shift compared to the photoabsorption properties of the FAD cofactor in its FADH• state in other Cry proteins from other species. The aim of this study is to understand this red shift by employing the tools of computational microscopy and, in particular, a QM/MM approach that relies on the polarizable embedding approximation.
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Affiliation(s)
- Katarina Kretschmer
- Institute of Physics, Carl von Ossietzky Universität Oldenburg, Carl-von-Ossietzky Str. 9-11, 26129 Oldenburg, Germany
| | - Anders Frederiksen
- Institute of Physics, Carl von Ossietzky Universität Oldenburg, Carl-von-Ossietzky Str. 9-11, 26129 Oldenburg, Germany
| | - Peter Reinholdt
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK 5230 Odense, Denmark
| | - Jacob Kongsted
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK 5230 Odense, Denmark
| | - Ilia A Solov'yov
- Institute of Physics, Carl von Ossietzky Universität Oldenburg, Carl-von-Ossietzky Str. 9-11, 26129 Oldenburg, Germany
- Research Centre for Neurosensory Science, Carl von Ossietzky Universität Oldenburg, Carl-von-Ossietzky Str. 9-11, 26129 Oldenburg, Germany
- Center for Nanoscale Dynamics (CENAD), Carl von Ossietzky Universität Oldenburg, Ammerländer Heerstr. 114-118, 26129 Oldenburg, Germany
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3
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Schuhmann F, Ramsay JL, Kattnig DR, Solov’yov IA. Structural Rearrangements of Pigeon Cryptochrome 4 Undergoing a Complete Redox Cycle. J Phys Chem B 2024; 128:3844-3855. [PMID: 38568745 PMCID: PMC11056986 DOI: 10.1021/acs.jpcb.4c00424] [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: 01/20/2024] [Revised: 03/04/2024] [Accepted: 03/11/2024] [Indexed: 04/26/2024]
Abstract
Cryptochrome is currently the major contender of a protein to underpin magnetoreception, the ability to sense the Earth's magnetic field. Among various types of cryptochromes, cryptochrome 4 has been identified as the likely magnetoreceptor in migratory birds. All-atom molecular dynamics (MD) studies have offered first insights into the structural dynamics of cryptochrome but are limited to a short time scale due to large computational demands. Here, we employ coarse-grained MD simulations to investigate the emergence of long-lived states and conformational changes in pigeon cryptochrome 4. Our coarse-grained simulations complete the picture by permitting observation on a significantly longer time scale. We observe conformational transitions in the phosphate-binding loop of pigeon cryptochrome 4 upon activation and identify prominent motions in residues 440-460, suggesting a possible role as a signaling state of the protein or as a gated interaction site for forming protein complexes that might facilitate downstream processes. The findings highlight the importance of considering longer time scales in studying cryptochrome dynamics and magnetoreception. Coarse-grained MD simulations offer a valuable tool to unravel the complex behavior of cryptochrome proteins and shed new light on the mechanisms underlying their role in magnetoreception. Further exploration of these conformational changes and their functional implications may contribute to a deeper understanding of the molecular mechanisms of magnetoreception in birds.
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Affiliation(s)
- Fabian Schuhmann
- Institute
of Physics, Carl von Ossietzky Universität
Oldenburg, Carl-von-Ossietzky Str. 9-11, Oldenburg 26129, Germany
- Niels
Bohr International Academy, Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, Copenhagen 2100, Denmark
| | - Jessica L. Ramsay
- Living
Systems Institute and Department of Physics, University of Exeter, Stocker Rd., Exeter EX4
4QD, U.K.
| | - Daniel R. Kattnig
- Living
Systems Institute and Department of Physics, University of Exeter, Stocker Rd., Exeter EX4
4QD, U.K.
| | - Ilia A. Solov’yov
- Institute
of Physics, Carl von Ossietzky Universität
Oldenburg, Carl-von-Ossietzky Str. 9-11, Oldenburg 26129, Germany
- Research
Centre for Neurosensory Science, Carl von
Ossietzky Universität Oldenburg, Carl-von-Ossietzky-Str. 9-11, Oldenburg 26129, Germany
- Center
for Nanoscale Dynamics (CENAD), Carl von
Ossietzky Universität Oldenburg, Ammerländer Heerstr. 114-118, Oldenburg 26129, Germany
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4
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Austvold CK, Keable SM, Procopio M, Usselman RJ. Quantitative measurements of reactive oxygen species partitioning in electron transfer flavoenzyme magnetic field sensing. Front Physiol 2024; 15:1348395. [PMID: 38370016 PMCID: PMC10869518 DOI: 10.3389/fphys.2024.1348395] [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] [Received: 12/02/2023] [Accepted: 01/16/2024] [Indexed: 02/20/2024] Open
Abstract
Biological magnetic field sensing that gives rise to physiological responses is of considerable importance in quantum biology. The radical pair mechanism (RPM) is a fundamental quantum process that can explain some of the observed biological magnetic effects. In magnetically sensitive radical pair (RP) reactions, coherent spin dynamics between singlet and triplet pairs are modulated by weak magnetic fields. The resulting singlet and triplet reaction products lead to distinct biological signaling channels and cellular outcomes. A prevalent RP in biology is between flavin semiquinone and superoxide (O2 •-) in the biological activation of molecular oxygen. This RP can result in a partitioning of reactive oxygen species (ROS) products to form either O2 •- or hydrogen peroxide (H2O2). Here, we examine magnetic sensing of recombinant human electron transfer flavoenzyme (ETF) reoxidation by selectively measuring O2 •- and H2O2 product distributions. ROS partitioning was observed between two static magnetic fields at 20 nT and 50 μT, with a 13% decrease in H2O2 singlet products and a 10% increase in O2 •- triplet products relative to 50 µT. RPM product yields were calculated for a realistic flavin/superoxide RP across the range of static magnetic fields, in agreement with experimental results. For a triplet born RP, the RPM also predicts about three times more O2 •- than H2O2, with experimental results exhibiting about four time more O2 •- produced by ETF. The method presented here illustrates the potential of a novel magnetic flavoprotein biological sensor that is directly linked to mitochondria bioenergetics and can be used as a target to study cell physiology.
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Affiliation(s)
- Chase K. Austvold
- Chemistry and Biochemistry, Montana State University, Bozeman, MT, United States
| | - Stephen M. Keable
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Maria Procopio
- Biophysics, Johns Hopkins University, Baltimore, MD, United States
| | - Robert J. Usselman
- Chemistry and Chemical Engineering, Florida Institute of Technology, Melbourne, FL, United States
- Computational Research At Florida Tech, Melbourne, FL, United States
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5
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Salerno KM, Domenico J, Le NQ, Balakrishnan K, McQuillen RJ, Stiles CD, Solov'yov IA, Martino CF. Long-Time Oxygen and Superoxide Localization in Arabidopsis thaliana Cryptochrome. J Chem Inf Model 2023; 63:6756-6767. [PMID: 37874902 DOI: 10.1021/acs.jcim.3c00325] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2023]
Abstract
Cryptochromes are proteins that are highly conserved across species and in many instances bind the flavin adenine dinucleotide (FAD) cofactor within their photolyase-homology region (PHR) domain. The FAD cofactor has multiple redox states that help catalyze reactions, and absorbs photons at about 450 nm, a feature linked to the light-related functions of cryptochrome proteins. Reactive oxygen species (ROS) are produced from redox reactions involving molecular oxygen and are involved in a myriad of biological processes. Superoxide O2•- is an exemplary ROS that may be formed through electron transfer from FAD to O2, generating an electron radical pair. Although the formation of a superoxide-FAD radical pair has been speculated, it is still unclear if the required process steps could be realized in cryptochrome. Here, we present results from molecular dynamics (MD) simulations of oxygen interacting with the PHR domain of Arabidopsis thaliana cryptochrome 1 (AtCRY1). Using MD simulation trajectories, oxygen binding locations are characterized through both the O2-FAD intermolecular distance and the local protein environment. Oxygen unbinding times are characterized through replica simulations of the bound oxygen. Simulations reveal that oxygen molecules can localize at certain sites within the cryptochrome protein for tens of nanoseconds, and superoxide molecules can localize for significantly longer. This relatively long-duration molecule binding suggests the possibility of an electron-transfer reaction leading to superoxide formation. Estimates of electron-transfer rates using the Marcus theory are performed for the identified potential binding sites. Molecular oxygen binding results are compared with recent results demonstrating long-time oxygen binding within the electron-transfer flavoprotein (ETF), another FAD binding protein.
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Affiliation(s)
- K Michael Salerno
- Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, Maryland 20723, United States
| | - Janna Domenico
- Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, Maryland 20723, United States
| | - Nam Q Le
- Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, Maryland 20723, United States
| | - Krithika Balakrishnan
- Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, Maryland 20723, United States
| | - Ryan J McQuillen
- Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, Maryland 20723, United States
| | - Christopher D Stiles
- Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, Maryland 20723, United States
| | - Ilia A Solov'yov
- Institute of Physics, Carl von Ossietzky University Oldenburg, Carl von Ossietzky Straße 9-11, 26129 Oldenburg, Germany
- Centre for Nanoscale Dynamics (CENAD), Carl von Ossietzky Universität Oldenburg, Carl von Ossietzky Straße 9-11, 26129 Oldenburg, Germany
- Centre for Neurosensory Science, Carl von Ossietzky Universität Oldenburg, Carl von Ossietzky Straße 9-11, 26129 Oldenburg, Germany
| | - Carlos F Martino
- Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, Maryland 20723, United States
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6
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Krylov VV, Osipova EA. Molecular Biological Effects of Weak Low-Frequency Magnetic Fields: Frequency-Amplitude Efficiency Windows and Possible Mechanisms. Int J Mol Sci 2023; 24:10989. [PMID: 37446167 DOI: 10.3390/ijms241310989] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 06/26/2023] [Accepted: 06/29/2023] [Indexed: 07/15/2023] Open
Abstract
This review covers the phenomenon of resonance-like responses of biological systems to low-frequency magnetic fields (LFMF). The historical development of this branch of magnetobiology, including the most notable biophysical models that explain the resonance-like responses of biological systems to LFMF with a specific frequency and amplitude, is given. Two groups can be distinguished among these models: one considers ion-cofactors of proteins as the primary targets for the LFMF influence, and the other regards the magnetic moments of particles in biomolecules. Attention is paid to the dependence of resonance-like LFMF effects on the cell type. A radical-pair mechanism of the magnetic field's influence on biochemical processes is described with the example of cryptochrome. Conditions for this mechanism's applicability to explain the biological effects of LFMF are given. A model of the influence of LFMF on radical pairs in biochemical oscillators, which can explain the frequency-amplitude efficiency windows of LFMF, is proposed.
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Affiliation(s)
- Viacheslav V Krylov
- Papanin Institute for Biology of Inland Waters, Russian Academy of Sciences, Borok 152742, Russia
| | - Elena A Osipova
- Papanin Institute for Biology of Inland Waters, Russian Academy of Sciences, Borok 152742, Russia
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7
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Matysik J, Gerhards L, Theiss T, Timmermann L, Kurle-Tucholski P, Musabirova G, Qin R, Ortmann F, Solov'yov IA, Gulder T. Spin Dynamics of Flavoproteins. Int J Mol Sci 2023; 24:ijms24098218. [PMID: 37175925 PMCID: PMC10179055 DOI: 10.3390/ijms24098218] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 04/19/2023] [Accepted: 04/27/2023] [Indexed: 05/15/2023] Open
Abstract
This short review reports the surprising phenomenon of nuclear hyperpolarization occurring in chemical reactions, which is called CIDNP (chemically induced dynamic nuclear polarization) or photo-CIDNP if the chemical reaction is light-driven. The phenomenon occurs in both liquid and solid-state, and electron transfer systems, often carrying flavins as electron acceptors, are involved. Here, we explain the physical and chemical properties of flavins, their occurrence in spin-correlated radical pairs (SCRP) and the possible involvement of flavin-carrying SCRPs in animal magneto-reception at earth's magnetic field.
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Affiliation(s)
- Jörg Matysik
- Institut für Analytische Chemie, Universität Leipzig, Linnéstr. 3, 04103 Leipzig, Germany
| | - Luca Gerhards
- Institut für Physik, Carl von Ossietzky Universität Oldenburg, Carl-von Ossietzky-Str. 9-11, 26129 Oldenburg, Germany
| | - Tobias Theiss
- Institut für Organische Chemie, Universität Leipzig, Johannisallee 29, 04103 Leipzig, Germany
| | - Lisa Timmermann
- Institut für Organische Chemie, Universität Leipzig, Johannisallee 29, 04103 Leipzig, Germany
| | | | - Guzel Musabirova
- Institut für Analytische Chemie, Universität Leipzig, Linnéstr. 3, 04103 Leipzig, Germany
| | - Ruonan Qin
- Institut für Analytische Chemie, Universität Leipzig, Linnéstr. 3, 04103 Leipzig, Germany
| | - Frank Ortmann
- TUM School of Natural Sciences, Technische Universität München, Lichtenbergstr. 4, 85748 Garching, Germany
| | - Ilia A Solov'yov
- Institut für Physik, Carl von Ossietzky Universität Oldenburg, Carl-von Ossietzky-Str. 9-11, 26129 Oldenburg, Germany
- Research Center for Neurosensory Science, Carl von Ossietzky Universität Oldenburg, Carl-von-Ossietzky-Str. 9-11, 26129 Oldenburg, Germany
- Center for Nanoscale Dynamics (CENAD), Carl von Ossietzky Universität Oldenburg, Carl-von-Ossietzky-Str. 9-11, 26129 Oldenburg, Germany
| | - Tanja Gulder
- Institut für Organische Chemie, Universität Leipzig, Johannisallee 29, 04103 Leipzig, Germany
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8
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Bradlaugh AA, Fedele G, Munro AL, Hansen CN, Hares JM, Patel S, Kyriacou CP, Jones AR, Rosato E, Baines RA. Essential elements of radical pair magnetosensitivity in Drosophila. Nature 2023; 615:111-116. [PMID: 36813962 PMCID: PMC9977682 DOI: 10.1038/s41586-023-05735-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 01/16/2023] [Indexed: 02/24/2023]
Abstract
Many animals use Earth's magnetic field (also known as the geomagnetic field) for navigation1. The favoured mechanism for magnetosensitivity involves a blue-light-activated electron-transfer reaction between flavin adenine dinucleotide (FAD) and a chain of tryptophan residues within the photoreceptor protein CRYPTOCHROME (CRY). The spin-state of the resultant radical pair, and therefore the concentration of CRY in its active state, is influenced by the geomagnetic field2. However, the canonical CRY-centric radical-pair mechanism does not explain many physiological and behavioural observations2-8. Here, using electrophysiology and behavioural analyses, we assay magnetic-field responses at the single-neuron and organismal levels. We show that the 52 C-terminal amino acid residues of Drosophila melanogaster CRY, lacking the canonical FAD-binding domain and tryptophan chain, are sufficient to facilitate magnetoreception. We also show that increasing intracellular FAD potentiates both blue-light-induced and magnetic-field-dependent effects on the activity mediated by the C terminus. High levels of FAD alone are sufficient to cause blue-light neuronal sensitivity and, notably, the potentiation of this response in the co-presence of a magnetic field. These results reveal the essential components of a primary magnetoreceptor in flies, providing strong evidence that non-canonical (that is, non-CRY-dependent) radical pairs can elicit magnetic-field responses in cells.
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Affiliation(s)
- Adam A Bradlaugh
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Giorgio Fedele
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
- Department of Biology, Ecology and Earth Sciences (DiBEST), University of Calabria, Rende, Italy
| | - Anna L Munro
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Celia Napier Hansen
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
| | - John M Hares
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
- Pelican Healthcare, Cardiff, UK
| | - Sanjai Patel
- Manchester Fly Facility, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | | | - Alex R Jones
- Biometrology, Chemical and Biological Sciences Department, National Physical Laboratory, Teddington, UK
| | - Ezio Rosato
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK.
| | - Richard A Baines
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK.
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9
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Martino CF, Jimenez P, Goldfarb M, Abdulla UG. Optimization of parameters in coherent spin dynamics of radical pairs in quantum biology. PLoS One 2023; 18:e0273404. [PMID: 36827400 PMCID: PMC9956872 DOI: 10.1371/journal.pone.0273404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 08/08/2022] [Indexed: 02/26/2023] Open
Abstract
Identification of the external electromagnetic fields and internal hyperfine parameters which optimize the quantum singlet-triplet yield of simplified radical pairs modeled by Schrödinger system with spin Hamiltonians given by the sum of Zeeman interaction and hyperfine coupling interaction terms are analyzed. A method that combines sensitivity analysis with Tikhonov regularization is implemented. Numerical results demonstrate that the quantum singlet-triplet yield of the radical pair system can be significantly reduced if optimization is pursued simultaneously for both external magnetic fields and internal hyperfine parameters. The results may contribute towards understanding the structure-function relationship of a putative magnetoreceptor to manipulate and enhance quantum coherences at room temperature and leveraging biofidelic function to inspire novel quantum devices.
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Affiliation(s)
- Carlos F. Martino
- Johns Hopkins University Applied Physics Lab, Laurel, MD, United States of America
- * E-mail:
| | - Pablo Jimenez
- Departamento de Física Médica, Instituto Balseiro, San Carlos de Bariloche, Argentina
| | - Max Goldfarb
- Department of Mathematical Sciences, Florida Institute of Technology, Melbourne, Fl, United States of America
| | - Ugur G. Abdulla
- Department of Mathematical Sciences, Florida Institute of Technology, Melbourne, Fl, United States of America
- Analysis & PDE Unit, Okinawa Institute of Science and Technology, Okinawa, Japan
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10
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Salerno KM, Domenico J, Le NQ, Stiles CD, Solov’yov IA, Martino CF. Long-Time Oxygen Localization in Electron Transfer Flavoprotein. J Chem Inf Model 2022; 62:4191-4199. [PMID: 35998902 PMCID: PMC9472800 DOI: 10.1021/acs.jcim.2c00430] [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: 04/18/2022] [Indexed: 11/30/2022]
Abstract
Reactive oxygen species (ROS) exert a wide range of biological effects from beneficial regulatory function to deleterious oxidative stress. The electron transfer flavoprotein (ETF) is ubiquitous to life and is associated with aerobic metabolism and ROS production due to its location in the mitochondria. Quantifying oxygen localization within the ETF complex is critical for understanding the potential for electron transfer and radical pair formation between flavin adenine dinucleotide (FAD) cofactor and superoxide during ROS formation. Our study employed all-atom molecular dynamics simulations and identified several novel, long-lived oxygen binding sites within the ETF complex that appear near the FAD cofactor. Site locations, the local electrostatic environment, and characteristic oxygen binding times for each site were evaluated to establish factors that may lead to possible charge transfer reactions and superoxide formation within the ETF complex. The study revealed that some oxygen binding sites are naturally linked to protein domain features, suggesting opportunities to engineer and control ROS production and subsequent dynamics.
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Affiliation(s)
- K. Michael Salerno
- The
Johns Hopkins University Applied Physics
Laboratory, 11100 Johns
Hopkins Road, Laurel, Maryland 20723, United States
| | - Janna Domenico
- The
Johns Hopkins University Applied Physics
Laboratory, 11100 Johns
Hopkins Road, Laurel, Maryland 20723, United States
| | - Nam Q. Le
- The
Johns Hopkins University Applied Physics
Laboratory, 11100 Johns
Hopkins Road, Laurel, Maryland 20723, United States
| | - Christopher D. Stiles
- The
Johns Hopkins University Applied Physics
Laboratory, 11100 Johns
Hopkins Road, Laurel, Maryland 20723, United States
| | - Ilia A. Solov’yov
- Institute
of Physics, Carl von Ossietzky University
Oldenburg, Carl von Ossietzky
Straße 9-11, 26129 Oldenburg, Germany
- Centre
for Neurosensory Science, Carl von Ossietzky
University Oldenburg, Carl von Ossietzky Straße 9-11, 26129 Oldenburg, Germany
| | - Carlos F. Martino
- The
Johns Hopkins University Applied Physics
Laboratory, 11100 Johns
Hopkins Road, Laurel, Maryland 20723, United States
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11
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Lin S, Zhu L, Tang Z, Wang ZL. Spin-selected electron transfer in liquid-solid contact electrification. Nat Commun 2022; 13:5230. [PMID: 36064784 PMCID: PMC9445095 DOI: 10.1038/s41467-022-32984-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Accepted: 08/26/2022] [Indexed: 01/12/2023] Open
Abstract
Electron transfer has been proven the dominant charge carrier during contact electrification at the liquid-solid interface. However, the effect of electron spin in contact electrification remains to be investigated. This study examines the charge transfer between different liquids and ferrimagnetic solids in a magnetic field, focusing on the contribution of O2 molecules to the liquid-solid contact electrification. The findings reveal that magnetic fields promote electron transfer at the O2-containing liquid-solid interfaces. Moreover, magnetic field-induced electron transfer increases at higher O2 concentrations in the liquids and decreases at elevated temperatures. The results indicate spin-selected electron transfer at liquid-solid interface. External magnetic fields can modulate the spin conversion of the radical pairs at the O2-containing liquid and ferrimagnetic solid interfaces due to the Zeeman interaction, promoting electron transfer. A spin-selected electron transfer model for liquid-solid contact electrification is further proposed based on the radical pair mechanism, in which the HO2 molecules and the free unpaired electrons from the ferrimagnetic solids are considered radical pairs. The spin conversion of the [HO2• •e-] pairs is affected by magnetic fields, rendering the electron transfer magnetic field-sensitive.
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Affiliation(s)
- Shiquan Lin
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 100083, P. R. China.,School of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Laipan Zhu
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 100083, P. R. China.,School of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Zhen Tang
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 100083, P. R. China.,School of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Zhong Lin Wang
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 100083, P. R. China. .,School of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China. .,School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA, 30332-0245, USA.
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12
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Zadeh-Haghighi H, Simon C. Magnetic field effects in biology from the perspective of the radical pair mechanism. J R Soc Interface 2022; 19:20220325. [PMID: 35919980 PMCID: PMC9346374 DOI: 10.1098/rsif.2022.0325] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 07/14/2022] [Indexed: 04/07/2023] Open
Abstract
Hundreds of studies have found that weak magnetic fields can significantly influence various biological systems. However, the underlying mechanisms behind these phenomena remain elusive. Remarkably, the magnetic energies implicated in these effects are much smaller than thermal energies. Here, we review these observations, and we suggest an explanation based on the radical pair mechanism, which involves the quantum dynamics of the electron and nuclear spins of transient radical molecules. While the radical pair mechanism has been studied in detail in the context of avian magnetoreception, the studies reviewed here show that magnetosensitivity is widespread throughout biology. We review magnetic field effects on various physiological functions, discussing static, hypomagnetic and oscillating magnetic fields, as well as isotope effects. We then review the radical pair mechanism as a potential unifying model for the described magnetic field effects, and we discuss plausible candidate molecules for the radical pairs. We review recent studies proposing that the radical pair mechanism provides explanations for isotope effects in xenon anaesthesia and lithium treatment of hyperactivity, magnetic field effects on the circadian clock, and hypomagnetic field effects on neurogenesis and microtubule assembly. We conclude by discussing future lines of investigation in this exciting new area of quantum biology.
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Affiliation(s)
- Hadi Zadeh-Haghighi
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada T2N 1N4
- Institute for Quantum Science and Technology, University of Calgary, Calgary, Alberta, Canada T2N 1N4
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada T2N 1N4
| | - Christoph Simon
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada T2N 1N4
- Institute for Quantum Science and Technology, University of Calgary, Calgary, Alberta, Canada T2N 1N4
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada T2N 1N4
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13
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Human magnetic sense is mediated by a light and magnetic field resonance-dependent mechanism. Sci Rep 2022; 12:8997. [PMID: 35637212 PMCID: PMC9151822 DOI: 10.1038/s41598-022-12460-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 05/10/2022] [Indexed: 11/13/2022] Open
Abstract
Numerous organisms use the Earth’s magnetic field as a sensory cue for migration, body alignment, or food search. Despite some contradictory reports, yet it is generally accepted that humans do not sense the geomagnetic field. Here, we demonstrate that a magnetic field resonance mechanism mediates light-dependent magnetic orientation in men, using a rotary chair experiment combined with a two-alternative forced choice paradigm. Two groups of subjects were classified with different magnetic orientation tendencies depending on the food context. Magnetic orientation of the subjects was sensitive to the wavelength of incident light and was critically dependent on blue light reaching the eyes. Importantly, it appears that a magnetic field resonance-dependent mechanism mediates these responses, as evidenced by disruption or augmentation of the ability to orient by radiofrequency magnetic fields at the Larmor frequency and the dependence of these effects on the angle between the radiofrequency and geomagnetic fields. Furthermore, inversion of the vertical component of the geomagnetic field revealed a non-canonical inclination compass effect on the magnetic orientation. These results establish the existence of a human magnetic sense and suggest an underlying quantum mechanical magnetoreception mechanism.
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14
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Deviers J, Cailliez F, de la Lande A, Kattnig DR. Anisotropic magnetic field effects in the re-oxidation of cryptochrome in the presence of scavenger radicals. J Chem Phys 2022; 156:025101. [PMID: 35032990 DOI: 10.1063/5.0078115] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The avian compass and many other of nature's magnetoreceptive traits are widely ascribed to the protein cryptochrome. There, magnetosensitivity is thought to emerge as the spin dynamics of radicals in the applied magnetic field enters in competition with their recombination. The first and dominant model makes use of a radical pair. However, recent studies have suggested that magnetosensitivity could be markedly enhanced for a radical triad, the primary radical pair of which undergoes a spin-selective recombination reaction with a third radical. Here, we test the practicality of this supposition for the reoxidation reaction of the reduced FAD cofactor in cryptochrome, which has been implicated with light-independent magnetoreception but appears irreconcilable with the classical radical pair mechanism (RPM). Based on the available realistic cryptochrome structures, we predict the magnetosensitivity of radical triad systems comprising the flavin semiquinone, the superoxide, and a tyrosine or ascorbyl scavenger radical. We consider many hyperfine-coupled nuclear spins, the relative orientation and placement of the radicals, their coupling by the electron-electron dipolar interaction, and spin relaxation in the superoxide radical in the limit of instantaneous decoherence, which have not been comprehensively considered before. We demonstrate that these systems can provide superior magnetosensitivity under realistic conditions, with implications for dark-state cryptochrome magnetoreception and other biological magneto- and isotope-sensitive radical recombination reactions.
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Affiliation(s)
- Jean Deviers
- Department of Physics and Living Systems Institute, University of Exeter, Stocker Road, EX4 4QD Exeter, United Kingdom
| | - Fabien Cailliez
- Institut de Chimie Physique, Université Paris Saclay, CNRS (UMR 8000), 15 avenue Jean Perrin, 91405 Orsay, France
| | - Aurélien de la Lande
- Institut de Chimie Physique, Université Paris Saclay, CNRS (UMR 8000), 15 avenue Jean Perrin, 91405 Orsay, France
| | - Daniel R Kattnig
- Department of Physics and Living Systems Institute, University of Exeter, Stocker Road, EX4 4QD Exeter, United Kingdom
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15
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Babcock N, Kattnig DR. Radical Scavenging Could Answer the Challenge Posed by Electron-Electron Dipolar Interactions in the Cryptochrome Compass Model. JACS AU 2021; 1:2033-2046. [PMID: 34841416 PMCID: PMC8611662 DOI: 10.1021/jacsau.1c00332] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Indexed: 06/13/2023]
Abstract
Many birds are endowed with a visual magnetic sense that may exploit magnetosensitive radical recombination processes in the protein cryptochrome. In this widely accepted but unproven model, geomagnetic sensitivity is suggested to arise from variations in the recombination rate of a pair of radicals, whose unpaired electron spins undergo coherent singlet-triplet interconversion in the geomagnetic field by coupling to nuclear spins via hyperfine interactions. However, simulations of this conventional radical pair mechanism (RPM) predicted only tiny magnetosensitivities for realistic conditions because the RPM's directional sensitivity is strongly suppressed by the intrinsic electron-electron dipolar (EED) interactions, casting doubt on its viability as a magnetic sensor. We show how this RPM-suppression problem is overcome in a three-radical system in which a third "scavenger" radical reacts with one member of the primary pair. We use this finding to predict substantial magnetic field effects that exceed those of the RPM in the presence of EED interactions in animal cryptochromes.
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Affiliation(s)
- Nathan
Sean Babcock
- Quantum
Biology Laboratory, Howard University, 2400 Sixth Street NW, Washington District of Columbia, 20059, United States of America
- Living
Systems Institute and Department of Physics University of Exeter, Stocker Road, Exeter, EX4 4QD, United Kingdom
| | - Daniel R. Kattnig
- Living
Systems Institute and Department of Physics University of Exeter, Stocker Road, Exeter, EX4 4QD, United Kingdom
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16
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Park J, Koehler F, Varnavides G, Antonini M, Anikeeva P. Influence of Magnetic Fields on Electrochemical Reactions of Redox Cofactor Solutions. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202106288] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jimin Park
- Department of Materials Science and Engineering Massachusetts Institute of Technology Cambridge MA 02139 USA
- Research Laboratory of Electronics and McGovern Institute for Brain Research Massachusetts Institute of Technology Cambridge MA 02139 USA
| | - Florian Koehler
- Research Laboratory of Electronics and McGovern Institute for Brain Research Massachusetts Institute of Technology Cambridge MA 02139 USA
- Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology Cambridge MA 02139 USA
| | - Georgios Varnavides
- Department of Materials Science and Engineering Massachusetts Institute of Technology Cambridge MA 02139 USA
- Research Laboratory of Electronics and McGovern Institute for Brain Research Massachusetts Institute of Technology Cambridge MA 02139 USA
| | - Marc‐Joseph Antonini
- Research Laboratory of Electronics and McGovern Institute for Brain Research Massachusetts Institute of Technology Cambridge MA 02139 USA
- Harvard/MIT Health Science & Technology Graduate Program Cambridge MA 02139 USA
| | - Polina Anikeeva
- Department of Materials Science and Engineering Massachusetts Institute of Technology Cambridge MA 02139 USA
- Research Laboratory of Electronics and McGovern Institute for Brain Research Massachusetts Institute of Technology Cambridge MA 02139 USA
- Department of Brain and Cognitive Sciences Massachusetts Institute of Technology Cambridge MA 02139 USA
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17
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Park J, Koehler F, Varnavides G, Antonini MJ, Anikeeva P. Influence of Magnetic Fields on Electrochemical Reactions of Redox Cofactor Solutions. Angew Chem Int Ed Engl 2021; 60:18295-18302. [PMID: 34097813 DOI: 10.1002/anie.202106288] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Indexed: 11/06/2022]
Abstract
Redox cofactors mediate many enzymatic processes and are increasingly employed in biomedical and energy applications. Exploring the influence of external magnetic fields on redox cofactor chemistry can enhance our understanding of magnetic-field-sensitive biological processes and allow the application of magnetic fields to modulate redox reactions involving cofactors. Through a combination of experiments and modeling, we investigate the influence of magnetic fields on electrochemical reactions in redox cofactor solutions. By employing flavin mononucleotide (FMN) cofactor as a model system, we characterize magnetically induced changes in Faradaic currents. We find that radical pair intermediates have negligible influence on current increases in FMN solution upon application of a magnetic field. The dominant mechanism underlying the observed current increases is the magneto-hydrodynamic effect. We extend our analyses to other diffusion-limited electrochemical reactions of redox cofactor solutions and arrive at similar conclusions, highlighting the opportunity to use this framework in redox cofactor chemistry.
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Affiliation(s)
- Jimin Park
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.,Research Laboratory of Electronics and McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Florian Koehler
- Research Laboratory of Electronics and McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.,Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Georgios Varnavides
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.,Research Laboratory of Electronics and McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Marc-Joseph Antonini
- Research Laboratory of Electronics and McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.,Harvard/MIT Health Science & Technology Graduate Program, Cambridge, MA, 02139, USA
| | - Polina Anikeeva
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.,Research Laboratory of Electronics and McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
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18
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Castello P, Jimenez P, Martino CF. The Role of Pulsed Electromagnetic Fields on the Radical Pair Mechanism. Bioelectromagnetics 2021; 42:491-500. [PMID: 34224591 DOI: 10.1002/bem.22358] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 06/08/2021] [Accepted: 06/19/2021] [Indexed: 11/09/2022]
Abstract
In recent decades, the use of pulsed electromagnetic fields (PEMF) in therapeutics has been one of the main fields of activity in the bioelectromagnetics arena. Nevertheless, progress in this area has been hindered by the lack of consensus on a biophysical mechanism of interaction that can satisfactorily explain how low-level, non-thermal electromagnetic fields would be able to sufficiently affect chemistry as to elicit biological effects in living organisms. This specifically applies in cases where the induced electric fields are too small to generate a biological response of any consequence. A growing body of experimental observations that would explain the nature of these effects speaks strongly about the involvement of a theory known as the radical pair mechanism (RPM). This mechanism explains how a pair of reactive oxygen species with distinct chemical fate can be influenced by a low-level external magnetic field through Zeeman and hyperfine interactions. So far, a study of the effects of complex spatiotemporal signals within the context of the RPM has not been performed. Here, we present a computational investigation of such effects by utilizing a generic PEMF test signal and RPM models of different complexity. Surprisingly, our results show how substantially different chemical results can be obtained within ranges that depend on the specific orientation of the PEMF test signal with respect to the background static magnetic field, its waveform, and both of their amplitudes. These results provide a basis for explaining the distinctive biological relevance of PEMF signals on radical pair chemical reactions. © 2021 Bioelectromagnetics Society.
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Affiliation(s)
- Pablo Castello
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Ciencias Exactas y Naturales, Universidad de Belgrano, Buenos Aires, Argentina
| | - Pablo Jimenez
- Centro Atómico Bariloche, CONICET, CNEA, S. C. de Bariloche, Argentina
| | - Carlos F Martino
- Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland
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19
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Carter CS, Huang SC, Searby CC, Cassaidy B, Miller MJ, Grzesik WJ, Piorczynski TB, Pak TK, Walsh SA, Acevedo M, Zhang Q, Mapuskar KA, Milne GL, Hinton AO, Guo DF, Weiss R, Bradberry K, Taylor EB, Rauckhorst AJ, Dick DW, Akurathi V, Falls-Hubert KC, Wagner BA, Carter WA, Wang K, Norris AW, Rahmouni K, Buettner GR, Hansen JM, Spitz DR, Abel ED, Sheffield VC. Exposure to Static Magnetic and Electric Fields Treats Type 2 Diabetes. Cell Metab 2020; 32:561-574.e7. [PMID: 33027675 PMCID: PMC7819711 DOI: 10.1016/j.cmet.2020.09.012] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 06/29/2020] [Accepted: 09/11/2020] [Indexed: 12/17/2022]
Abstract
Aberrant redox signaling underlies the pathophysiology of many chronic metabolic diseases, including type 2 diabetes (T2D). Methodologies aimed at rebalancing systemic redox homeostasis have had limited success. A noninvasive, sustained approach would enable the long-term control of redox signaling for the treatment of T2D. We report that static magnetic and electric fields (sBE) noninvasively modulate the systemic GSH-to-GSSG redox couple to promote a healthier systemic redox environment that is reducing. Strikingly, when applied to mouse models of T2D, sBE rapidly ameliorates insulin resistance and glucose intolerance in as few as 3 days with no observed adverse effects. Scavenging paramagnetic byproducts of oxygen metabolism with SOD2 in hepatic mitochondria fully abolishes these insulin sensitizing effects, demonstrating that mitochondrial superoxide mediates induction of these therapeutic changes. Our findings introduce a remarkable redox-modulating phenomenon that exploits endogenous electromagneto-receptive mechanisms for the noninvasive treatment of T2D, and potentially other redox-related diseases.
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Affiliation(s)
- Calvin S Carter
- Department of Pediatrics and Division of Medical Genetics and Genomics, University of Iowa Hospitals & Clinics, Iowa City, IA, USA.
| | - Sunny C Huang
- Department of Pediatrics and Division of Medical Genetics and Genomics, University of Iowa Hospitals & Clinics, Iowa City, IA, USA; Medical Scientist Training Program, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Charles C Searby
- Department of Pediatrics and Division of Medical Genetics and Genomics, University of Iowa Hospitals & Clinics, Iowa City, IA, USA
| | - Benjamin Cassaidy
- Department of Pediatrics and Division of Medical Genetics and Genomics, University of Iowa Hospitals & Clinics, Iowa City, IA, USA
| | - Michael J Miller
- Department of Physics and Astronomy, University of Iowa, Iowa City, IA, USA
| | - Wojciech J Grzesik
- Fraternal Order of Eagles Diabetes Research Center, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Ted B Piorczynski
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT, USA
| | - Thomas K Pak
- Department of Pediatrics and Division of Medical Genetics and Genomics, University of Iowa Hospitals & Clinics, Iowa City, IA, USA; Medical Scientist Training Program, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Susan A Walsh
- Department of Radiology, Division of Nuclear Medicine, University of Iowa Hospitals & Clinics, Iowa City, IA, USA
| | - Michael Acevedo
- Department of Radiology, Division of Nuclear Medicine, University of Iowa Hospitals & Clinics, Iowa City, IA, USA
| | - Qihong Zhang
- Department of Pediatrics and Division of Medical Genetics and Genomics, University of Iowa Hospitals & Clinics, Iowa City, IA, USA
| | - Kranti A Mapuskar
- Free Radical and Radiation Biology Program, Department of Radiation Oncology, Holden Comprehensive Cancer Center, University of Iowa Hospitals & Clinics, Iowa City, IA, USA
| | - Ginger L Milne
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Antentor O Hinton
- Fraternal Order of Eagles Diabetes Research Center, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Deng-Fu Guo
- Department of Neuroscience and Pharmacology, University of Iowa Hospitals & Clinics, Iowa City, IA, USA
| | - Robert Weiss
- Department of Internal Medicine, Division of Cardiology, University of Iowa Hospitals & Clinics, Iowa City, IA, USA
| | - Kyle Bradberry
- Fraternal Order of Eagles Diabetes Research Center, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Eric B Taylor
- Fraternal Order of Eagles Diabetes Research Center, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA; Department of Molecular Physiology and Biophysics, University of Iowa Hospitals & Clinics, Iowa City, IA, USA
| | - Adam J Rauckhorst
- Fraternal Order of Eagles Diabetes Research Center, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA; Department of Molecular Physiology and Biophysics, University of Iowa Hospitals & Clinics, Iowa City, IA, USA
| | - David W Dick
- Department of Radiology, Division of Nuclear Medicine, University of Iowa Hospitals & Clinics, Iowa City, IA, USA
| | - Vamsidhar Akurathi
- Department of Radiology, Division of Nuclear Medicine, University of Iowa Hospitals & Clinics, Iowa City, IA, USA
| | - Kelly C Falls-Hubert
- Medical Scientist Training Program, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA; Free Radical and Radiation Biology Program, Department of Radiation Oncology, Holden Comprehensive Cancer Center, University of Iowa Hospitals & Clinics, Iowa City, IA, USA
| | - Brett A Wagner
- Free Radical and Radiation Biology Program, Department of Radiation Oncology, Holden Comprehensive Cancer Center, University of Iowa Hospitals & Clinics, Iowa City, IA, USA
| | - Walter A Carter
- Department of Pediatrics and Division of Medical Genetics and Genomics, University of Iowa Hospitals & Clinics, Iowa City, IA, USA
| | - Kai Wang
- College of Public Health, Department of Biostatistics, University of Iowa, Iowa City, IA, USA
| | - Andrew W Norris
- Department of Pediatrics and Division of Medical Genetics and Genomics, University of Iowa Hospitals & Clinics, Iowa City, IA, USA; Fraternal Order of Eagles Diabetes Research Center, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Kamal Rahmouni
- Department of Neuroscience and Pharmacology, University of Iowa Hospitals & Clinics, Iowa City, IA, USA
| | - Garry R Buettner
- Free Radical and Radiation Biology Program, Department of Radiation Oncology, Holden Comprehensive Cancer Center, University of Iowa Hospitals & Clinics, Iowa City, IA, USA
| | - Jason M Hansen
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT, USA
| | - Douglas R Spitz
- Free Radical and Radiation Biology Program, Department of Radiation Oncology, Holden Comprehensive Cancer Center, University of Iowa Hospitals & Clinics, Iowa City, IA, USA
| | - E Dale Abel
- Fraternal Order of Eagles Diabetes Research Center, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA; Department of Internal Medicine, Division of Endocrinology and Metabolism, University of Iowa Hospitals & Clinics, Iowa City, IA, USA
| | - Val C Sheffield
- Department of Pediatrics and Division of Medical Genetics and Genomics, University of Iowa Hospitals & Clinics, Iowa City, IA, USA.
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20
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Gaps in Knowledge Relevant to the "Guidelines for Limiting Exposure to Time-Varying Electric and Magnetic Fields (1 Hz-100 kHz)". HEALTH PHYSICS 2020; 118:533-542. [PMID: 32251081 DOI: 10.1097/hp.0000000000001261] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Sources of low-frequency fields are widely found in modern society. All wires or devices carrying or using electricity generate extremely low frequency (ELF) electric fields (EFs) and magnetic fields (MFs), but they decline rapidly with distance to the source. High magnetic flux densities are usually found in the vicinity of power lines and close to equipment using strong electrical currents, but can also be found in buildings with unbalanced return currents, or indoor transformer stations. For decades, epidemiological as well as experimental studies have addressed possible health effects of exposure to ELF-MFs. The main goal of ICNIRP is to protect people and the environment from detrimental exposure to all forms of non-ionizing radiation (NIR). To this end, ICNIRP provides advice and guidance by developing and disseminating exposure guidelines based on the available scientific research. Research in the low-frequency range began more than 40 years ago, and there is now a large body of literature available on which ICNIRP set its protection guidelines. A review of the literature has been carried out to identify possible relevant knowledge gaps, and the aim of this statement is to describe data gaps in research that would, if addressed, assist ICNIRP in further developing guidelines and setting revised recommendations on limiting exposure to electric and magnetic fields. It is articulated in two parts: the main document, which reviews the science related to LF data gaps, and the annex, which explains the methodology used to identify the data gaps.
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21
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Babcock N, Kattnig DR. Electron-Electron Dipolar Interaction Poses a Challenge to the Radical Pair Mechanism of Magnetoreception. J Phys Chem Lett 2020; 11:2414-2421. [PMID: 32141754 PMCID: PMC7145362 DOI: 10.1021/acs.jpclett.0c00370] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 03/06/2020] [Indexed: 06/10/2023]
Abstract
A visual magnetic sense in migratory birds has been hypothesized to rely on a radical pair reaction in the protein cryptochrome. In this model, magnetic sensitivity originates from coherent spin dynamics, as the radicals couple to magnetic nuclei via hyperfine interactions. Prior studies have often neglected the electron-electron dipolar (EED) coupling from this hypothesis. We show that EED interactions suppress the anisotropic response to the geomagnetic field by the radical pair mechanism in cryptochrome and that this attenuation is unlikely to be mitigated by mutual cancellation of the EED and electronic exchange coupling, as previously suggested. We then demonstrate that this limitation may be overcome by extending the conventional model to include a third, nonreacting radical. We predict that hyperfine effects could work in concert with three-radical dipolar interactions to tailor a superior magnetic response, thereby providing a new principle for magnetosensitivity with applications for sensing, navigation, and the assessment of biological magnetic field effects.
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Affiliation(s)
- Nathan
S. Babcock
- Living Systems Institute and Department
of Physics, University of Exeter, Stocker Road, Exeter EX4 4QD, United
Kingdom
| | - Daniel R. Kattnig
- Living Systems Institute and Department
of Physics, University of Exeter, Stocker Road, Exeter EX4 4QD, United
Kingdom
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22
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Player TC, Hore PJ. Viability of superoxide-containing radical pairs as magnetoreceptors. J Chem Phys 2020; 151:225101. [PMID: 31837685 DOI: 10.1063/1.5129608] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The ability of night-migratory songbirds to sense the direction of the Earth's magnetic field is increasingly attributed to a photochemical mechanism in which the magnetic field acts on transient radical pairs in cryptochrome flavoproteins located in the birds' eyes. The magnetically sensitive species is commonly assumed to be [FAD•- TrpH•+], formed by sequential light-induced intraprotein electron transfers from a chain of tryptophan residues to the flavin adenine dinucleotide chromophore. However, some evidence points to superoxide, O2 •-, as an alternative partner for the flavin radical. The absence of hyperfine interactions in O2 •- could lead to a more sensitive magnetic compass, but only if the electron spin relaxation of the O2 •- radical is much slower than normally expected for a small mobile radical with an orbitally degenerate electronic ground state. In this study we use spin dynamics simulations to model the sensitivity of a flavin-superoxide radical pair to the direction of a 50 μT magnetic field. By varying parameters that characterize the local environment and molecular dynamics of the radicals, we identify the highly restrictive conditions under which a O2 •--containing radical pair could form the basis of a geomagnetic compass sensor. We conclude that the involvement of superoxide in compass magnetoreception must remain highly speculative until further experimental evidence is forthcoming.
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Affiliation(s)
- Thomas C Player
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, United Kingdom
| | - P J Hore
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, United Kingdom
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23
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Husen P, Nielsen C, Martino CF, Solov'yov IA. Molecular Oxygen Binding in the Mitochondrial Electron Transfer Flavoprotein. J Chem Inf Model 2019; 59:4868-4879. [PMID: 31665600 DOI: 10.1021/acs.jcim.9b00702] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Reactive oxygen species such as superoxide are potentially harmful byproducts of the aerobic metabolism in the inner mitochondrial membrane, and complexes I, II, III of the electron transport chain have been identified as primary sources. The mitochondrial fatty acid b-oxidation pathway may also play a yet uncharacterized role in reactive oxygen species generation, apparently at the level of the electron transfer flavoprotein:ubiquinone oxidoreductase (ETF:QO) and/or its redox partner electron-transfer flavoprotein (ETF). These enzymes comprise a key pathway through which electrons are sequentially shuttled from several dehydrogenases to the respiratory chain. The exact mechanisms of superoxide production have not been fully established, but a crucial starting point would be the binding of molecular oxygen within one of the protein complexes. The present investigation offers a comprehensive computational approach for the determination of binding modes and characteristic binding times of small molecules inside proteins, which is then used to reveal several O2 binding sites near the flavin adenine dinucleotide cofactor of the ETF enzyme. The binding sites are further characterized to extract the necessary parameters for further studies of possible electron transfer between flavin and O2 leading to radical pair formation and possible superoxide production.
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Affiliation(s)
- Peter Husen
- Department of Physics, Chemistry and Pharmacy , University of Southern Denmark , Odense , Denmark
| | - Claus Nielsen
- Department of Physics, Chemistry and Pharmacy , University of Southern Denmark , Odense , Denmark
| | - Carlos F Martino
- Biomedical and Chemical Engineering and Science Department , Florida Institute of Technology , Melbourne , Florida 32901 , United States
| | - Ilia A Solov'yov
- Department of Physics , Carl von Ossietzky Universität Oldenburg , Oldenburg , Germany
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24
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Navigating at night: fundamental limits on the sensitivity of radical pair magnetoreception under dim light. Q Rev Biophys 2019; 52:e9. [DOI: 10.1017/s0033583519000076] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Abstract
Night-migratory songbirds appear to sense the direction of the Earth's magnetic field via radical pair intermediates formed photochemically in cryptochrome flavoproteins contained in photoreceptor cells in their retinas. It is an open question whether this light-dependent mechanism could be sufficiently sensitive given the low-light levels experienced by nocturnal migrants. The scarcity of available photons results in significant uncertainty in the signal generated by the magnetoreceptors distributed around the retina. Here we use results from Information Theory to obtain a lower bound estimate of the precision with which a bird could orient itself using only geomagnetic cues. Our approach bypasses the current lack of knowledge about magnetic signal transduction and processing in vivo by computing the best-case compass precision under conditions where photons are in short supply. We use this method to assess the performance of three plausible cryptochrome-derived flavin-containing radical pairs as potential magnetoreceptors.
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25
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Atkins C, Bajpai K, Rumball J, Kattnig DR. On the optimal relative orientation of radicals in the cryptochrome magnetic compass. J Chem Phys 2019. [DOI: 10.1063/1.5115445] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Chadsley Atkins
- Institute and Department of Physics, University of Exeter, North Park Road, Exeter EX4 4QL, United Kingdom
| | - Kieran Bajpai
- Institute and Department of Physics, University of Exeter, North Park Road, Exeter EX4 4QL, United Kingdom
| | - Jeremy Rumball
- Institute and Department of Physics, University of Exeter, North Park Road, Exeter EX4 4QL, United Kingdom
| | - Daniel R. Kattnig
- Institute and Department of Physics, University of Exeter, North Park Road, Exeter EX4 4QL, United Kingdom
- Living Systems Institute and Department of Physics, University of Exeter, Stocker Road, Exeter EX4 4QD, United Kingdom
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26
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Terpilovskii MA, Khmelevskoy DA, Shchegolev BF, Surma SV, Stefanov VE, Sukharzhevskii SM, Goncharov NV. A Hypomagnetic Field Modulates the Susceptibility of Erythrocytes to tert-Butyl Hydroperoxide in Rats. Biophysics (Nagoya-shi) 2019. [DOI: 10.1134/s0006350919030230] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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27
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Nielsen C, Hui R, Lui WY, Solov’yov IA. Towards predicting intracellular radiofrequency radiation effects. PLoS One 2019; 14:e0213286. [PMID: 30870450 PMCID: PMC6417702 DOI: 10.1371/journal.pone.0213286] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 02/12/2019] [Indexed: 11/19/2022] Open
Abstract
Recent experiments have reported an effect of weak radiofrequency magnetic fields in the MHz-range on the concentrations of reactive oxygen species (ROS) in living cells. Since the energy that could possibly be deposited by the radiation is orders of magnitude smaller than the energy of molecular thermal motion, it was suggested that the effect was caused by the interaction of RF magnetic fields with transient radical pairs within the cells, affecting the ROS formation rates through the radical pair mechanism. It is, however, at present not entirely clear how to predict RF magnetic field effects at certain field frequency and intensity in nanoscale biomolecular systems. We suggest a possible recipe for interpreting the radiofrequency effects in cells by presenting a general workflow for calculation of the reactive perturbations inside a cell as a function of RF magnetic field strength and frequency. To justify the workflow, we discuss the effects of radiofrequency magnetic fields on generic spin systems to particularly illustrate how the reactive radicals could be affected by specific parameters of the experiment. We finally argue that the suggested workflow can be used to predict effects of radiofrequency magnetic fields on radical pairs in biological cells, which is specially important for wireless recharging technologies where one has to know of any harmful effects that exposure to such radiation might cause.
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Affiliation(s)
- Claus Nielsen
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense M, Denmark
| | - Ron Hui
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, China
| | - Wing-Yee Lui
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Ilia A. Solov’yov
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense M, Denmark
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28
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Dhiman SK, Galland P. Effects of weak static magnetic fields on the gene expression of seedlings of Arabidopsis thaliana. JOURNAL OF PLANT PHYSIOLOGY 2018; 231:9-18. [PMID: 30199755 DOI: 10.1016/j.jplph.2018.08.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Revised: 08/26/2018] [Accepted: 08/29/2018] [Indexed: 05/20/2023]
Abstract
Magnetic-field reception of animals and plants is currently discussed in the framework of a cryptochrome-based radical-pair mechanism. Efforts to unravel magnetoreception in plants suffered historically from several shortcomings, most prominently, the conspicuous absence of detailed stimulus-response relationships. To determine the sensitivity of seedlings of Arabidopsis thaliana to weak static magnetic fields we generated stimulus-response curves between near zero and 188 μT for the transcript levels of the genes rbcl, cab4, pal4 and ef1. The moderate magneto-responsiveness of dark-grown seedlings was greatly enhanced under blue light, and for rbcl and pal4 also under red light. The stimulus-response curves obtained under blue light of constant photon-fluence rate displayed multiple maxima and thus a pattern fundamentally different from that prevalent in plant and animal physiology. A double mutant lacking cryptochromes 1 and 2 displayed altered stimulus-response curves without losing, however, magneto-responsiveness completely. A reversal of the magnetic field direction substantially affected the gene expression and the quantity of CAB-protein (chlorophyll a,b-binding protein). The majority of our results are at variance with the notion of cryptochromes acting as the only magnetic-field sensors. They do not, however, exclude the possibility that cryptochromes participate in the magnetic field reception of Arabidopsis. The findings have the unexpected implication that cryptochrome- and phytochrome-mediated plant responses can be modulated by the strength and the orientation of the local geomagnetic field.
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Affiliation(s)
- Sunil K Dhiman
- Faculty of Biology, Philipps-University Marburg, Karl-von-Frisch-Str. 8, D-35032 Marburg, Germany; Kirori Mal College, Delhi University (North Campus), Delhi-110007, India.
| | - Paul Galland
- Faculty of Biology, Philipps-University Marburg, Karl-von-Frisch-Str. 8, D-35032 Marburg, Germany.
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29
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Binhi VN, Prato FS. Rotations of macromolecules affect nonspecific biological responses to magnetic fields. Sci Rep 2018; 8:13495. [PMID: 30202025 PMCID: PMC6131245 DOI: 10.1038/s41598-018-31847-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 08/24/2018] [Indexed: 12/19/2022] Open
Abstract
We have previously proposed that there are at least two initial molecular transduction mechanisms needed to explain specific and nonspecific biological effects of weak magnetic fields. For the specific effect associated with animal magnetic navigation, the radical pair mechanism is the leading hypothesis; it associates the specialised magnetic sense with the radical pairs located in the eye retina. In contrast to the magnetic sense, nonspecific effects occur through the interaction of magnetic fields with magnetic moments dispersed over the organism. However, it is unlikely that the radical pair mechanism can explain such nonspecific phenomena. In order to explain these, we further develop our physical model for the case of magnetic moments residing in rotating molecules. It is shown that, in some conditions, the precession of the magnetic moments that reside on rotating molecules can be slowed relative to the immediate biophysical structures. In terms of quantum mechanics this corresponds to the mixing of the quantum levels of magnetic moments. Hence this mechanism is called the Level Mixing Mechanism, or the LMM. The results obtained are magnetic field-dependences that are in good agreement with known experiments where biological effects arise in response to the reversal of the magnetic field vector.
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Affiliation(s)
| | - Frank S Prato
- Lawson Health Research Institute, Ontario, N6A 4V2, Canada.
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30
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Kimø SM, Friis I, Solov'yov IA. Atomistic Insights into Cryptochrome Interprotein Interactions. Biophys J 2018; 115:616-628. [PMID: 30078611 DOI: 10.1016/j.bpj.2018.06.029] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 06/11/2018] [Accepted: 06/29/2018] [Indexed: 11/30/2022] Open
Abstract
It is striking that the mechanism by which birds sense geomagnetic fields during the biannual migration seasons is not entirely understood. A protein believed to be responsible for avian magnetoreception is the flavoprotein cryptochrome (CRY), which fulfills many of the criteria for a magnetic field sensor. Some experiments, however, indicate that magnetoreception in birds may be disturbed by extremely weak radio frequency fields, an effect that likely cannot be described by an isolated CRY protein. An explanation can possibly be delivered if CRY binds to another protein inside a cell that would possess certain biochemical properties, and it is, therefore, important to identify possible intracellular CRY interaction partners. The goal of this study is to investigate a possible interaction between CRY4 and the iron-sulfur-containing assembly protein (ISCA1) from Erithacus rubecula (European robin), which has recently been proposed to be relevant for magnetic field sensing. The interaction between the proteins is established through classical molecular dynamics simulations for several possible protein-docking modes. The analysis of these simulations concludes that the ISCA1 complex and CRY4 are capable of binding; however, the peculiarities of this binding argue strongly against ISCA1 as relevant for magnetoreception.
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Affiliation(s)
- Sarafina M Kimø
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense M, Denmark
| | - Ida Friis
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense M, Denmark
| | - Ilia A Solov'yov
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense M, Denmark.
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31
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Hong G, Pachter R, Ritz T. Coupling Drosophila melanogaster Cryptochrome Light Activation and Oxidation of the Kvβ Subunit Hyperkinetic NADPH Cofactor. J Phys Chem B 2018; 122:6503-6510. [PMID: 29847128 DOI: 10.1021/acs.jpcb.8b03493] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Motivated by the observations on the involvement of light-induced processes in the Drosophila melanogaster cryptochrome (DmCry) in regulation of the neuronal firing rate, which is achieved by a redox-state change of its voltage-dependent K+ channel Kvβ subunit hyperkinetic (Hk) reduced nicotinamide adenine dinucleotide phosphate (NADPH) cofactor, we propose in this work two hypothetical pathways that may potentially enable such coupling. In the first pathway, triggered by blue-light-induced formation of a radical pair [FAD•-TRP•+] in DmCry, the hole (TRP•+) may hop to Hk, for example, through a tryptophan chain and oxidize NADPH, possibly leading to inhibition of the N-terminus inactivation in the K+ channel. In a second possible pathway, DmCry's FAD•- is reoxidized by molecular oxygen, producing H2O2, which then diffuses to Hk and oxidizes NADPH. In this work, by applying a combination of quantum and empirical-based methods for free-energy calculations, we find that the oxidation of NADPH by TRP•+ or H2O2 and the reoxidation of FAD•- by O2 are thermodynamically feasible. Our results may have an implication in identifying a magnetic sensing signal transduction pathway, specifically upon Drosophila's Hk NADPH cofactor oxidation, with a subsequent inhibition of the K+ channel N-terminus inactivation gate, permitting K+ flux.
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Affiliation(s)
- Gongyi Hong
- Air Force Research Laboratory , Wright-Patterson Air Force Base , Dayton , Ohio 45433-7702 , United States
| | - Ruth Pachter
- Air Force Research Laboratory , Wright-Patterson Air Force Base , Dayton , Ohio 45433-7702 , United States
| | - Thorsten Ritz
- Department of Physics and Astronomy , University of California , Irvine , California 92697-4575 , United States
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32
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Thoss F, Bartsch B. A model of the FAD redox cycle describes the dynamics of the effect of the geomagnetic field on the human visual system. BIOLOGICAL CYBERNETICS 2017; 111:347-352. [PMID: 28776258 DOI: 10.1007/s00422-017-0725-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 07/27/2017] [Indexed: 06/07/2023]
Abstract
In experimental studies, we could show that the visual threshold of man is influenced by the geomagnetic field. One of the results was that the threshold shows periodic fluctuations when the vertical component of the field is reversed periodically. The maximum of these oscillations occurred at a period duration of 110 s. To explain this phenomenon, we chose the process that likely underlies the navigation of birds in the geomagnetic field: the light reaction of the FAD component of cryptochrome in the retina. The human retina contains cryptpochrome like the bird retina. Based on the investigations of Müller and Ahmad (J Biol Chem 286:21033-21040, 2011) and Solov'yov and Schulten (J Phys Chem B 116:1089-1099, 2012), we designed a model of the light-induced reduction and subsequent reoxidation of FAD. This model contains a radical pair, whose interconversion dynamics are affected by the geomagnetic field. The parameters of the model were partly calculated from the data of our experimental investigation and partly taken from the results of other authors. These parameters were then optimized by adjusting the model behaviour to the experimental results. The simulation of the finished model shows that the concentrations of all substances included show really oscillations with the frequency of the modelled magnetic field. After optimization of the parameters, the oscillations of FAD and FADH* show maximal amplitude at a period duration of 110 s, as was observed in the experiment. This makes it most likely that the signal, which influences the visual system, originates from FADH* (signalling state).
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Affiliation(s)
- Franz Thoss
- Carl-Ludwig-Institute of Physiology, University of Leipzig, Liebigstr. 27, 04103, Leipzig, Germany.
| | - Bengt Bartsch
- Carl-Ludwig-Institute of Physiology, University of Leipzig, Liebigstr. 27, 04103, Leipzig, Germany
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33
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Kattnig DR. Radical-Pair-Based Magnetoreception Amplified by Radical Scavenging: Resilience to Spin Relaxation. J Phys Chem B 2017; 121:10215-10227. [DOI: 10.1021/acs.jpcb.7b07672] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Daniel R. Kattnig
- Living Systems Institute
and Department of Physics, University of Exeter, Stocker Road, Exeter, Devon, EX4 4QD, United Kingdom
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34
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Friis I, Sjulstok E, Solov'yov IA. Computational reconstruction reveals a candidate magnetic biocompass to be likely irrelevant for magnetoreception. Sci Rep 2017; 7:13908. [PMID: 29066765 PMCID: PMC5654753 DOI: 10.1038/s41598-017-13258-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 09/20/2017] [Indexed: 11/30/2022] Open
Abstract
Birds use the magnetic field of the Earth to navigate during their annual migratory travel. The possible mechanism to explain the biophysics of this compass sense involves electron transfers within the photoreceptive protein cryptochrome. The magnetoreceptive functioning of cryptochromes is supposedly facilitated through an iron rich polymer complex which couples to multiple cryptochromes. The present investigation aims to independently reconstruct this complex and describe its interaction with Drosophila melanogaster cryptochromes. The polymer complex consists of ISCA1 protein monomers with internally bound iron sulphur clusters and simultaneously binds ten cryptochromes. Through molecular dynamics we have analysed the stability of the ISCA1-cryptochrome complex and characterized the interaction at the binding sites between individual cryptochrome and ISCA1. It is found that the cryptochrome binding to the ISCA1 polymer is not uniform and that the binding affinity depends on its placement along the ISCA1 polymer. This finding supports the claim that the individual ISCA1 monomer acts as possible intracellular interaction partner of cryptochrome, but the proposed existence of an elongated ISCA1 polymer with multiple attached cryptochromes appears to be questionable.
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Affiliation(s)
- Ida Friis
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK-5230, Odense M, Denmark.
| | - Emil Sjulstok
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK-5230, Odense M, Denmark
| | - Ilia A Solov'yov
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK-5230, Odense M, Denmark.
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35
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Wiltschko R, Ahmad M, Nießner C, Gehring D, Wiltschko W. Light-dependent magnetoreception in birds: the crucial step occurs in the dark. J R Soc Interface 2017; 13:rsif.2015.1010. [PMID: 27146685 PMCID: PMC4892254 DOI: 10.1098/rsif.2015.1010] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 04/12/2016] [Indexed: 11/24/2022] Open
Abstract
The Radical Pair Model proposes that the avian magnetic compass is based on spin-chemical processes: since the ratio between the two spin states singlet and triplet of radical pairs depends on their alignment in the magnetic field, it can provide information on magnetic directions. Cryptochromes, blue light-absorbing flavoproteins, with flavin adenine dinucleotide as chromophore, are suggested as molecules forming the radical pairs underlying magnetoreception. When activated by light, cryptochromes undergo a redox cycle, in the course of which radical pairs are generated during photo-reduction as well as during light-independent re-oxidation. This raised the question as to which radical pair is crucial for mediating magnetic directions. Here, we present the results from behavioural experiments with intermittent light and magnetic field pulses that clearly show that magnetoreception is possible in the dark interval, pointing to the radical pair formed during flavin re-oxidation. This differs from the mechanism considered for cryptochrome signalling the presence of light and rules out most current models of an avian magnetic compass based on the radical pair generated during photo-reduction. Using the radical pair formed during re-oxidation may represent a specific adaptation of the avian magnetic compass.
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Affiliation(s)
- Roswitha Wiltschko
- FB Biowissenschaften, Goethe-Universität Frankfurt, Max-von-Laue-Straße 13, 60438 Frankfurt am Main, Germany
| | - Margaret Ahmad
- Université Pierre et Marie Curie, Casier 156, 4 Place Jussieu, 75005 Paris, France
| | - Christine Nießner
- FB Biowissenschaften, Goethe-Universität Frankfurt, Max-von-Laue-Straße 13, 60438 Frankfurt am Main, Germany
| | - Dennis Gehring
- FB Biowissenschaften, Goethe-Universität Frankfurt, Max-von-Laue-Straße 13, 60438 Frankfurt am Main, Germany
| | - Wolfgang Wiltschko
- FB Biowissenschaften, Goethe-Universität Frankfurt, Max-von-Laue-Straße 13, 60438 Frankfurt am Main, Germany
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36
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Novikov VV, Yablokova EV, Fesenko EE. The role of hydroxyl radicals and calcium ions in the priming of a respiratory burst in neutrophils and the increase in luminol-dependent blood chemiluminescence on exposure to combined magnetic fields with a very weak low-frequency alternating component. Biophysics (Nagoya-shi) 2017. [DOI: 10.1134/s0006350917030149] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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37
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Magnetic Fields Modulate Blue-Light-Dependent Regulation of Neuronal Firing by Cryptochrome. J Neurosci 2017; 36:10742-10749. [PMID: 27798129 DOI: 10.1523/jneurosci.2140-16.2016] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 08/18/2016] [Indexed: 11/21/2022] Open
Abstract
Many animals are able to sense the Earth's geomagnetic field to enable behaviors such as migration. It is proposed that the magnitude and direction of the geomagnetic field modulates the activity of cryptochrome (CRY) by influencing photochemical radical pair intermediates within the protein. However, this proposal will remain theoretical until a CRY-dependent effect on a receptor neuron is shown to be modified by an external magnetic field (MF). It is established that blue-light (BL) photoactivation of CRY is sufficient to depolarize and activate Drosophila neurons. Here, we show that this CRY-dependent effect is significantly potentiated in the presence of an applied MF (100 mT). We use electrophysiological recordings from larval identified motoneurons, in which CRY is ectopically expressed, to show that BL-dependent depolarization of membrane potential and increased input resistance are markedly potentiated by an MF. Analysis of membrane excitability shows that these effects of MF exposure evoke increased action potential firing. Almost nothing is known about the mechanism by which a magnetically induced change in CRY activity might produce a behavioral response. We further report that specific structural changes to the protein alter the impact of the MF in ways that are strikingly similar to those from recent behavioral studies into the magnetic sense of Drosophila These observations provide the first direct experimental evidence to support the hypothesis that MF modulation of CRY activity is capable of influencing neuron activity to allow animal magnetoreception. SIGNIFICANCE STATEMENT The biophysical mechanism of animal magnetoreception is still unclear. The photoreceptor protein cryptochrome has risen to prominence as a candidate magnetoreceptor molecule based on multiple reports derived from behavioral studies. However, the role of cryptochrome as a magnetoreceptor remains controversial primarily because of a lack of direct experimental evidence linking magnetic field (MF) exposure to a change in neuronal activity. Here, we show that exposure to an MF (100 mT) is sufficient to potentiate the ability of light-activated cryptochrome to increase neuronal action potential firing. Our results provide critical missing evidence to show that the activity of cryptochrome is sensitive to an external MF that is capable of modifying animal behavior.
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38
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Binhi VN, Prato FS. Biological effects of the hypomagnetic field: An analytical review of experiments and theories. PLoS One 2017; 12:e0179340. [PMID: 28654641 PMCID: PMC5487043 DOI: 10.1371/journal.pone.0179340] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 05/26/2017] [Indexed: 11/19/2022] Open
Abstract
During interplanetary flights in the near future, a human organism will be exposed to prolonged periods of a hypomagnetic field that is 10,000 times weaker than that of Earth's. Attenuation of the geomagnetic field occurs in buildings with steel walls and in buildings with steel reinforcement. It cannot be ruled out also that a zero magnetic field might be interesting in biomedical studies and therapy. Further research in the area of hypomagnetic field effects, as shown in this article, is capable of shedding light on a fundamental problem in biophysics-the problem of primary magnetoreception. This review contains, currently, the most extensive bibliography on the biological effects of hypomagnetic field. This includes both a review of known experimental results and the putative mechanisms of magnetoreception and their explanatory power with respect to the hypomagnetic field effects. We show that the measured correlations of the HMF effect with HMF magnitude and inhomogeneity and type and duration of exposure are statistically absent. This suggests that there is no general biophysical MF target similar for different organisms. This also suggests that magnetoreception is not necessarily associated with evolutionary developed specific magnetoreceptors in migrating animals and magnetotactic bacteria. Independently, there is nonspecific magnetoreception that is common for all organisms, manifests itself in very different biological observables as mostly random reactions, and is a result of MF interaction with magnetic moments at a physical level-moments that are present everywhere in macromolecules and proteins and can sometimes transfer the magnetic signal at the level of downstream biochemical events. The corresponding universal mechanism of magnetoreception that has been given further theoretical analysis allows one to determine the parameters of magnetic moments involved in magnetoreception-their gyromagnetic ratio and thermal relaxation time-and so to better understand the nature of MF targets in organisms.
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Affiliation(s)
- Vladimir N. Binhi
- A.M. Prokhorov General Physics Institute, Moscow, Russia
- M.V. Lomonosov Moscow State University, Moscow, Russia
| | - Frank S. Prato
- Lawson Health Research Institute, Ontario, Canada
- University of Western Ontario, Ontario, Canada
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39
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Pinzon-Rodriguez A, Muheim R. Zebra finches have a light-dependent magnetic compass similar to migratory birds. J Exp Biol 2017; 220:1202-1209. [DOI: 10.1242/jeb.148098] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 01/10/2017] [Indexed: 12/24/2022]
Abstract
ABSTRACT
Birds have a light-dependent magnetic compass that provides information about the spatial alignment of the geomagnetic field. It is proposed to be located in the avian retina and mediated by a light-induced, radical-pair mechanism involving cryptochromes as sensory receptor molecules. To investigate how the behavioural responses of birds under different light spectra match with cryptochromes as the primary magnetoreceptor, we examined the spectral properties of the magnetic compass in zebra finches. We trained birds to relocate a food reward in a spatial orientation task using magnetic compass cues. The birds were well oriented along the trained magnetic compass axis when trained and tested under low-irradiance 521 nm green light. In the presence of a 1.4 MHz radio-frequency electromagnetic (RF)-field, the birds were disoriented, which supports the involvement of radical-pair reactions in the primary magnetoreception process. Birds trained and tested under 638 nm red light showed a weak tendency to orient ∼45 deg clockwise of the trained magnetic direction. Under low-irradiance 460 nm blue light, they tended to orient along the trained magnetic compass axis, but were disoriented under higher irradiance light. Zebra finches trained and tested under high-irradiance 430 nm indigo light were well oriented along the trained magnetic compass axis, but disoriented in the presence of a RF-field. We conclude that magnetic compass responses of zebra finches are similar to those observed in nocturnally migrating birds and agree with cryptochromes as the primary magnetoreceptor, suggesting that light-dependent, radical-pair-mediated magnetoreception is a common property for all birds, including non-migratory species.
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Affiliation(s)
| | - Rachel Muheim
- Department of Biology, Lund University, Biology Building B, Lund 223 62, Sweden
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40
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Melekhova OP. Use of fundamental properties of embryonic objects for studying potential environmental effects of technogenic impacts. Russ J Dev Biol 2017. [DOI: 10.1134/s1062360417010088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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41
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Compass systems. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2017; 203:447-453. [DOI: 10.1007/s00359-016-1140-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 12/04/2016] [Accepted: 12/12/2016] [Indexed: 11/26/2022]
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42
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The Quantum Biology of Reactive Oxygen Species Partitioning Impacts Cellular Bioenergetics. Sci Rep 2016; 6:38543. [PMID: 27995996 PMCID: PMC5172244 DOI: 10.1038/srep38543] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 11/10/2016] [Indexed: 12/15/2022] Open
Abstract
Quantum biology is the study of quantum effects on biochemical mechanisms and biological function. We show that the biological production of reactive oxygen species (ROS) in live cells can be influenced by coherent electron spin dynamics, providing a new example of quantum biology in cellular regulation. ROS partitioning appears to be mediated during the activation of molecular oxygen (O2) by reduced flavoenzymes, forming spin-correlated radical pairs (RPs). We find that oscillating magnetic fields at Zeeman resonance alter relative yields of cellular superoxide (O2•-) and hydrogen peroxide (H2O2) ROS products, indicating coherent singlet-triplet mixing at the point of ROS formation. Furthermore, the orientation-dependence of magnetic stimulation, which leads to specific changes in ROS levels, increases either mitochondrial respiration and glycolysis rates. Our results reveal quantum effects in live cell cultures that bridge atomic and cellular levels by connecting ROS partitioning to cellular bioenergetics.
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43
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Salo AB, Husen P, Solov’yov IA. Charge Transfer at the Qo-Site of the Cytochrome bc1 Complex Leads to Superoxide Production. J Phys Chem B 2016; 121:1771-1782. [DOI: 10.1021/acs.jpcb.6b10403] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Adrian Bøgh Salo
- Department of Physics,
Chemistry
and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Peter Husen
- Department of Physics,
Chemistry
and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Ilia A. Solov’yov
- Department of Physics,
Chemistry
and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
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Multiscale description of avian migration: from chemical compass to behaviour modeling. Sci Rep 2016; 6:36709. [PMID: 27830725 PMCID: PMC5103213 DOI: 10.1038/srep36709] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 10/19/2016] [Indexed: 11/08/2022] Open
Abstract
Despite decades of research the puzzle of the magnetic sense of migratory songbirds has still not been unveiled. Although the problem really needs a multiscale description, most of the individual research efforts were focused on single scale investigations. Here we seek to establish a multiscale link between some of the scales involved, and in particular construct a bridge between electron spin dynamics and migratory bird behaviour. In order to do that, we first consider a model cyclic reaction scheme that could form the basis of the avian magnetic compass. This reaction features a fast spin-dependent process which leads to an unusually precise compass. We then propose how the reaction could be realized in a realistic molecular environment, and argue that it is consistent with the known facts about avian magnetoreception. Finally we show how the microscopic dynamics of spins could possibly be interpreted by a migrating bird and used for the navigational purpose.
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Worster S, Kattnig DR, Hore PJ. Spin relaxation of radicals in cryptochrome and its role in avian magnetoreception. J Chem Phys 2016; 145:035104. [DOI: 10.1063/1.4958624] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Affiliation(s)
- Susannah Worster
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Daniel R. Kattnig
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - P. J. Hore
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
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Affiliation(s)
- P. J. Hore
- Department of Chemistry, University of Oxford, Oxford OX1 3QZ, United Kingdom;
| | - Henrik Mouritsen
- Institut für Biologie und Umweltwissenschaften, Carl von Ossietzky Universität Oldenburg, DE-26111 Oldenburg, Germany;
- Research Centre for Neurosensory Sciences, University of Oldenburg, DE-26111 Oldenburg, Germany
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Machovina MM, Usselman RJ, DuBois JL. Monooxygenase Substrates Mimic Flavin to Catalyze Cofactorless Oxygenations. J Biol Chem 2016; 291:17816-28. [PMID: 27307041 DOI: 10.1074/jbc.m116.730051] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Indexed: 01/16/2023] Open
Abstract
Members of the antibiotic biosynthesis monooxygenase family catalyze O2-dependent oxidations and oxygenations in the absence of any metallo- or organic cofactor. How these enzymes surmount the kinetic barrier to reactions between singlet substrates and triplet O2 is unclear, but the reactions have been proposed to occur via a flavin-like mechanism, where the substrate acts in lieu of a flavin cofactor. To test this model, we monitored the uncatalyzed and enzymatic reactions of dithranol, a substrate for the nogalamycin monooxygenase (NMO) from Streptomyces nogalater As with flavin, dithranol oxidation was faster at a higher pH, although the reaction did not appear to be base-catalyzed. Rather, conserved asparagines contributed to suppression of the substrate pKa The same residues were critical for enzymatic catalysis that, consistent with the flavoenzyme model, occurred via an O2-dependent slow step. Evidence for a superoxide/substrate radical pair intermediate came from detection of enzyme-bound superoxide during turnover. Small molecule and enzymatic superoxide traps suppressed formation of the oxygenation product under uncatalyzed conditions, whereas only the small molecule trap had an effect in the presence of NMO. This suggested that NMO both accelerated the formation and directed the recombination of a superoxide/dithranyl radical pair. These catalytic strategies are in some ways flavin-like and stand in contrast to the mechanisms of urate oxidase and (1H)-3-hydroxy-4-oxoquinaldine 2,4-dioxygenase, both cofactor-independent enzymes that surmount the barriers to direct substrate/O2 reactivity via markedly different means.
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Affiliation(s)
- Melodie M Machovina
- From the Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59715-3400
| | - Robert J Usselman
- From the Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59715-3400
| | - Jennifer L DuBois
- From the Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59715-3400
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Hiscock HG, Worster S, Kattnig DR, Steers C, Jin Y, Manolopoulos DE, Mouritsen H, Hore PJ. The quantum needle of the avian magnetic compass. Proc Natl Acad Sci U S A 2016; 113:4634-9. [PMID: 27044102 PMCID: PMC4855607 DOI: 10.1073/pnas.1600341113] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Migratory birds have a light-dependent magnetic compass, the mechanism of which is thought to involve radical pairs formed photochemically in cryptochrome proteins in the retina. Theoretical descriptions of this compass have thus far been unable to account for the high precision with which birds are able to detect the direction of the Earth's magnetic field. Here we use coherent spin dynamics simulations to explore the behavior of realistic models of cryptochrome-based radical pairs. We show that when the spin coherence persists for longer than a few microseconds, the output of the sensor contains a sharp feature, referred to as a spike. The spike arises from avoided crossings of the quantum mechanical spin energy-levels of radicals formed in cryptochromes. Such a feature could deliver a heading precision sufficient to explain the navigational behavior of migratory birds in the wild. Our results (i) afford new insights into radical pair magnetoreception, (ii) suggest ways in which the performance of the compass could have been optimized by evolution, (iii) may provide the beginnings of an explanation for the magnetic disorientation of migratory birds exposed to anthropogenic electromagnetic noise, and (iv) suggest that radical pair magnetoreception may be more of a quantum biology phenomenon than previously realized.
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Affiliation(s)
- Hamish G Hiscock
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - Susannah Worster
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - Daniel R Kattnig
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - Charlotte Steers
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - Ye Jin
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - David E Manolopoulos
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - Henrik Mouritsen
- Institut für Biologie und Umweltwissenschaften, Carl von Ossietzky Universität Oldenburg, 26111 Oldenburg, Germany; Research Centre for Neurosensory Sciences, University of Oldenburg, 26111 Oldenburg, Germany
| | - P J Hore
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom;
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49
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Mo WC, Zhang ZJ, Wang DL, Liu Y, Bartlett PF, He RQ. Shielding of the Geomagnetic Field Alters Actin Assembly and Inhibits Cell Motility in Human Neuroblastoma Cells. Sci Rep 2016; 6:22624. [PMID: 27029216 PMCID: PMC4814845 DOI: 10.1038/srep22624] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 02/17/2016] [Indexed: 12/28/2022] Open
Abstract
Accumulating evidence has shown that absence of the geomagnetic field (GMF), the so-called hypomagnetic field (HMF) environment, alters the biological functions in seemingly non-magnetosensitive cells and organisms, which indicates that the GMF could be sensed by non-iron-rich and non-photo-sensing cells. The underlying mechanisms of the HMF effects on those cells are closely related to their GMF sensation but remain poorly understood so far. Previously, we found that the HMF represses expressions of genes associated with cell migration and cytoskeleton assembly in human neuroblastoma cells (SH-SY5Y cell line). Here, we measured the HMF-induced changes on cell morphology, adhesion, motility and actin cytoskeleton in SH-SY5Y cells. The HMF inhibited cell adhesion and migration accompanied with a reduction in cellular F-actin amount. Moreover, following exposure to the HMF, the number of cell processes was reduced and cells were smaller in size and more round in shape. Furthermore, disordered kinetics of actin assembly in vitro were observed during exposure to the HMF, as evidenced by the presence of granule and meshed products. These results indicate that elimination of the GMF affects assembly of the motility-related actin cytoskeleton, and suggest that F-actin is a target of HMF exposure and probably a mediator of GMF sensation.
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Affiliation(s)
- Wei-Chuan Mo
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.,Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Zi-Jian Zhang
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.,Beijing University of Chinese Medicine, Beijing 100029, China
| | - Dong-Liang Wang
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Ying Liu
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Perry F Bartlett
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Rong-Qiao He
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.,Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China.,Alzheimer's Disease Center, Beijing Institute for Brain Disorders, Capital Medical University, Beijing, 10069, China
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Kattnig DR, Solov'yov IA, Hore PJ. Electron spin relaxation in cryptochrome-based magnetoreception. Phys Chem Chem Phys 2016; 18:12443-56. [PMID: 27020113 DOI: 10.1039/c5cp06731f] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The magnetic compass sense of migratory birds is thought to rely on magnetically sensitive radical pairs formed photochemically in cryptochrome proteins in the retina. An important requirement of this hypothesis is that electron spin relaxation is slow enough for the Earth's magnetic field to have a significant effect on the coherent spin dynamics of the radicals. It is generally assumed that evolutionary pressure has led to protection of the electron spins from irreversible loss of coherence in order that the underlying quantum dynamics can survive in a noisy biological environment. Here, we address this question for a structurally characterized model cryptochrome expected to share many properties with the putative avian receptor protein. To this end we combine all-atom molecular dynamics simulations, Bloch-Redfield relaxation theory and spin dynamics calculations to assess the effects of spin relaxation on the performance of the protein as a compass sensor. Both flavin-tryptophan and flavin-Z˙ radical pairs are studied (Z˙ is a radical with no hyperfine interactions). Relaxation is considered to arise from modulation of hyperfine interactions by librational motions of the radicals and fluctuations in certain dihedral angles. For Arabidopsis thaliana cryptochrome 1 (AtCry1) we find that spin relaxation implies optimal radical pair lifetimes of the order of microseconds, and that flavin-Z˙ pairs are less affected by relaxation than flavin-tryptophan pairs. Our results also demonstrate that spin relaxation in isolated AtCry1 is incompatible with the long coherence times that have been postulated to explain the disruption of the avian magnetic compass sense by weak radiofrequency magnetic fields. We conclude that a cryptochrome sensor in vivo would have to differ dynamically, if not structurally, from isolated AtCry1. Our results clearly mark the limits of the current hypothesis and lead to a better understanding of the operation of radical pair magnetic sensors in noisy biological environments.
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Affiliation(s)
- Daniel R Kattnig
- Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory, OX1 3QZ, UK.
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