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Nair PS, Zadeh-Haghighi H, Simon C. Radical pair model for magnetic field effects on NMDA receptor activity. Sci Rep 2024; 14:3628. [PMID: 38351304 PMCID: PMC10864372 DOI: 10.1038/s41598-024-54343-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 02/12/2024] [Indexed: 02/16/2024] Open
Abstract
The N-methyl-D-aspartate receptor is a prominent player in brain development and functioning. Perturbations to its functioning through external stimuli like magnetic fields can potentially affect the brain in numerous ways. Various studies have shown that magnetic fields of varying strengths affect these receptors. We propose that the radical pair mechanism, a quantum mechanical process, could explain some of these field effects. Radicals of the form [Formula: see text], where R is a protein residue that can be Serine or Tyrosine, are considered for this study. The variation in the singlet fractional yield of the radical pairs, as a function of magnetic field strength, is calculated to understand how the magnetic field affects the products of the radical pair reactions. Based on the results, the radical pair mechanism is a likely candidate for explaining the magnetic field effects observed on the receptor activity. The model predicts changes in the behaviour of the system as magnetic field strength is varied and also predicts certain isotope effects. The results further suggest that similar effects on radical pairs could be a plausible explanation for various magnetic field effects within the brain.
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Affiliation(s)
- Parvathy S Nair
- Department of Physics, Indian Institute of Science Education and Research (IISER), Tirupati, Tirupati, Andhra Pradesh, 517507, India.
| | - Hadi Zadeh-Haghighi
- Department of Physics and Astronomy, University of Calgary, Calgary, AB, T2N 1N4, Canada.
- Institute for Quantum Science and Technology, University of Calgary, Calgary, AB, T2N 1N4, Canada.
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 1N4, Canada.
| | - Christoph Simon
- Department of Physics and Astronomy, University of Calgary, Calgary, AB, T2N 1N4, Canada.
- Institute for Quantum Science and Technology, University of Calgary, Calgary, AB, T2N 1N4, Canada.
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 1N4, Canada.
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2
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Chuang KH, Qian C, Gilad A, Pelled G. Magnetogenetic stimulation inside MRI induces spontaneous and evoked changes in neural circuits activity in rats. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.14.571681. [PMID: 38168269 PMCID: PMC10760131 DOI: 10.1101/2023.12.14.571681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
The ability to modulate specific neural circuits and simultaneously visualize and measure brain activity with MRI would greatly impact understanding brain function in health and disease. The combination of neurostimulation methods and MRI in animal models have already shown promise in elucidating fundamental mechanisms associated with brain activity. We developed an innovative magnetogenetics neurostimulation technology that can trigger neural activity through magnetic fields. Similar to other genetic-based neuromodulation methods, magnetogenetics offers cell-, area- and temporal-specific control of neural activity. However, the magnetogenetics protein (Electromagnetic Preceptive Gene (EPG)) are activated by non-invasive magnetic fields, providing a unique way to target neural circuits by the MRI gradients while simultaneously measure their effect on brain activity. EPG was expressed in rat's visual cortex and the amplitude of low-frequency fluctuation (fALFF), resting-state functional connectivity (FC), and sensory activation was measured using a 7T MRI. The results demonstrate that EPG-expressing rats had significantly higher signal fluctuations in the visual areas and stronger FC in sensory areas consistent with known anatomical visuosensory and visuomotor connections. This new technology complements the existing neurostimulation toolbox and provides a mean to study brain function in a minimally-invasive way which was not possible previously.
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Affiliation(s)
- Kai-Hsiang Chuang
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
- Australian Research Council Training Centre for Innovation in Biomedical Imaging Technology, Brisbane, QLD, Australia
| | - Chunqi Qian
- Department of Radiology, Michigan State University, East Lansing, MI, United States
| | - Assaf Gilad
- Department of Radiology, Michigan State University, East Lansing, MI, United States
- Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, MI, United States
| | - Galit Pelled
- Department of Radiology, Michigan State University, East Lansing, MI, United States
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, United States
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3
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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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4
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Binhi VN. Statistical Amplification of the Effects of Weak Magnetic Fields in Cellular Translation. Cells 2023; 12:cells12050724. [PMID: 36899858 PMCID: PMC10000676 DOI: 10.3390/cells12050724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 02/21/2023] [Accepted: 02/22/2023] [Indexed: 03/12/2023] Open
Abstract
We assume that the enzymatic processes of recognition of amino acids and their addition to the synthesized molecule in cellular translation include the formation of intermediate pairs of radicals with spin-correlated electrons. The mathematical model presented describes the changes in the probability of incorrectly synthesized molecules in response to a change in the external weak magnetic field. A relatively high chance of errors has been shown to arise from the statistical enhancement of the low probability of local incorporation errors. This statistical mechanism does not require a long thermal relaxation time of electron spins of about 1 μs-a conjecture often used to match theoretical models of magnetoreception with experiments. The statistical mechanism allows for experimental verification by testing the usual Radical Pair Mechanism properties. In addition, this mechanism localizes the site where magnetic effects originate, the ribosome, which makes it possible to verify it by biochemical methods. This mechanism predicts a random nature of the nonspecific effects caused by weak and hypomagnetic fields and agrees with the diversity of biological responses to a weak magnetic field.
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Affiliation(s)
- Vladimir N Binhi
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilov St., 119991 Moscow, Russia
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5
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Grüning G, Wong SY, Gerhards L, Schuhmann F, Kattnig DR, Hore PJ, Solov’yov IA. Effects of Dynamical Degrees of Freedom on Magnetic Compass Sensitivity: A Comparison of Plant and Avian Cryptochromes. J Am Chem Soc 2022; 144:22902-22914. [DOI: 10.1021/jacs.2c06233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Affiliation(s)
- Gesa Grüning
- Department of Physics, Carl von Ossietzky University, Carl-von-Ossietzky-Street 9-11, 26129 Oldenburg, Germany
| | - Siu Ying Wong
- Department of Physics, Carl von Ossietzky University, Carl-von-Ossietzky-Street 9-11, 26129 Oldenburg, Germany
| | - Luca Gerhards
- Department of Physics, Carl von Ossietzky University, Carl-von-Ossietzky-Street 9-11, 26129 Oldenburg, Germany
| | - Fabian Schuhmann
- Department of Physics, Carl von Ossietzky University, Carl-von-Ossietzky-Street 9-11, 26129 Oldenburg, Germany
| | - Daniel R. Kattnig
- Department of Physics and Living Systems Institute, University of Exeter, Stocker Road, Exeter EX4 4QD, U.K
| | - P. J. Hore
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, U.K
| | - Ilia A. Solov’yov
- Department of Physics, Carl von Ossietzky University, Carl-von-Ossietzky-Street 9-11, 26129 Oldenburg, Germany
- Research Center for Neurosensory Science, Carl von Ossietzky Universität Oldenburg, 26111 Oldenburg, Germany
- Center for Nanoscale Dynamics (CENAD), Carl von Ossietzky Universität Oldenburg, Institut für Physik, Ammerländer Heerstreet 114-118, 26129 Oldenburg, Germany
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6
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Smith LD, Chowdhury FT, Peasgood I, Dawkins N, Kattnig DR. Driven Radical Motion Enhances Cryptochrome Magnetoreception: Toward Live Quantum Sensing. J Phys Chem Lett 2022; 13:10500-10506. [PMID: 36332112 PMCID: PMC9677492 DOI: 10.1021/acs.jpclett.2c02840] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 10/25/2022] [Indexed: 06/16/2023]
Abstract
The mechanism underlying magnetoreception has long eluded explanation. A popular hypothesis attributes this sense to the quantum coherent spin dynamics and spin-selective recombination reactions of radical pairs in the protein cryptochrome. However, concerns about the validity of the hypothesis have been raised because unavoidable inter-radical interactions, such as the strong electron-electron dipolar coupling, appear to suppress its sensitivity. We demonstrate that sensitivity can be restored by driving the spin system through a modulation of the inter-radical distance. It is shown that this dynamical process markedly enhances geomagnetic field sensitivity in strongly coupled radical pairs via Landau-Zener-Stückelberg-Majorana transitions between singlet and triplet states. These findings suggest that a "live" harmonically driven magnetoreceptor can be more sensitive than its "dead" static counterpart.
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Ramsay J, Kattnig DR. Radical triads, not pairs, may explain effects of hypomagnetic fields on neurogenesis. PLoS Comput Biol 2022; 18:e1010519. [PMID: 36108063 PMCID: PMC9514667 DOI: 10.1371/journal.pcbi.1010519] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 09/27/2022] [Accepted: 08/27/2022] [Indexed: 12/03/2022] Open
Abstract
Adult hippocampal neurogenesis and hippocampus-dependent cognition in mice have been found to be adversely affected by hypomagnetic field exposure. The effect concurred with a reduction of reactive oxygen species in the absence of the geomagnetic field. A recent theoretical study suggests a mechanistic interpretation of this phenomenon in the framework of the Radical Pair Mechanism. According to this model, a flavin-superoxide radical pair, born in the singlet spin configuration, undergoes magnetic field-dependent spin dynamics such that the pair’s recombination is enhanced as the applied magnetic field is reduced. This model has two ostensible weaknesses: a) the assumption of a singlet initial state is irreconcilable with known reaction pathways generating such radical pairs, and b) the model neglects the swift spin relaxation of free superoxide, which abolishes any magnetic sensitivity in geomagnetic/hypomagnetic fields. We here suggest that a model based on a radical triad and the assumption of a secondary radical scavenging reaction can, in principle, explain the phenomenon without unnatural assumptions, thus providing a coherent explanation of hypomagnetic field effects in biology. The hippocampal region of the brain plays a major role in learning and memory functionality. In male mice, shielding of the Earth’s magnetic field was found to decrease hippocampal neurogenesis, i.e. the formation of new neurons, following from a decrease in levels of reactive oxygen species. In this study, we suggest an explanation in terms of spin dynamics of a three radical system composed of flavin-semiquinone, superoxide and ascorbyl radical. This model agrees with the experimental data whilst retaining realistic parameters for a biological system, unlike the Radical Pair Mechanism.
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Affiliation(s)
- Jess Ramsay
- Living Systems Institute and Department of Physics, University of Exeter, Exeter, Devon, United Kingdom
| | - Daniel R. Kattnig
- Living Systems Institute and Department of Physics, University of Exeter, Exeter, Devon, United Kingdom
- * E-mail:
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8
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Wong CJK, Tai YK, Yap JLY, Fong CHH, Loo LSW, Kukumberg M, Fröhlich J, Zhang S, Li JZ, Wang JW, Rufaihah AJ, Franco-Obregón A. Brief exposure to directionally-specific pulsed electromagnetic fields stimulates extracellular vesicle release and is antagonized by streptomycin: A potential regenerative medicine and food industry paradigm. Biomaterials 2022; 287:121658. [PMID: 35841726 DOI: 10.1016/j.biomaterials.2022.121658] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 06/24/2022] [Indexed: 12/12/2022]
Abstract
Pulsing electromagnetic fields (PEMFs) have been shown to promote in vitro and in vivo myogeneses via mitohormetic survival adaptations of which secretome activation is a key component. A single 10-min exposure of donor myoblast cultures to 1.5 mT amplitude PEMFs produced a conditioned media (pCM) capable of enhancing the myogenesis of recipient cultures to a similar degree as direct magnetic exposure. Downwardly-directed magnetic fields produced greater secretome responses than upwardly-directed fields in adherent and fluid-suspended myoblasts. The suspension paradigm allowed for the rapid concentrating of secreted factors, particularly of extracellular vesicles. The brief conditioning of basal media from magnetically-stimulated myoblasts was capable of conferring myoblast survival to a greater degree than basal media supplemented with fetal bovine serum (5%). Downward-directed magnetic fields, applied directly to cells or in the form of pCM, upregulated the protein expression of TRPC channels, markers for cell cycle progression and myogenesis. Direct magnetic exposure produced mild oxidative stress, whereas pCM provision did not, providing a survival advantage on recipient cells. Streptomycin, a TRP channel antagonist, precluded the production of a myogenic pCM. We present a methodology employing a brief and non-invasive PEMF-exposure paradigm to effectively stimulate secretome production and release for commercial or clinical exploitation.
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Affiliation(s)
- Craig Jun Kit Wong
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, 119228, Singapore; Institute of Health Technology and Innovation (iHealthtech), National University of Singapore, 117599, Singapore; Biolonic Currents Electromagnetic Pulsing Systems Laboratory (BICEPS), National University of Singapore, 117599, Singapore
| | - Yee Kit Tai
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, 119228, Singapore; Institute of Health Technology and Innovation (iHealthtech), National University of Singapore, 117599, Singapore; Biolonic Currents Electromagnetic Pulsing Systems Laboratory (BICEPS), National University of Singapore, 117599, Singapore.
| | - Jasmine Lye Yee Yap
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, 119228, Singapore; Institute of Health Technology and Innovation (iHealthtech), National University of Singapore, 117599, Singapore; Biolonic Currents Electromagnetic Pulsing Systems Laboratory (BICEPS), National University of Singapore, 117599, Singapore
| | - Charlene Hui Hua Fong
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, 119228, Singapore; Institute of Health Technology and Innovation (iHealthtech), National University of Singapore, 117599, Singapore; Biolonic Currents Electromagnetic Pulsing Systems Laboratory (BICEPS), National University of Singapore, 117599, Singapore
| | - Larry Sai Weng Loo
- Institute of Bioengineering and Bioimaging, A*STAR, The Nanos, #06-01, 31 Biopolis Way, 138669, Singapore; Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 117593, Singapore
| | - Marek Kukumberg
- Department of Obstetrics & Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, 119228, Singapore; Healthy Longevity Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, 119228, Singapore
| | - Jürg Fröhlich
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, 119228, Singapore; Fields at Work GmbH, Zurich 8032, Switzerland
| | - Sitong Zhang
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, 119228, Singapore; Nanomedicine Translational Research Programme, Centre for NanoMedicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Jing Ze Li
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, 119228, Singapore
| | - Jiong-Wei Wang
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, 119228, Singapore; Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 117593, Singapore; Nanomedicine Translational Research Programme, Centre for NanoMedicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Cardiovascular Research Institute, National University Heart Centre Singapore, Singapore, 119074, Singapore
| | - Abdul Jalil Rufaihah
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, 119228, Singapore; Healthy Longevity Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, 119228, Singapore; School of Applied Sciences, Temasek Polytechnic, 529757, Singapore
| | - Alfredo Franco-Obregón
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, 119228, Singapore; Institute of Health Technology and Innovation (iHealthtech), National University of Singapore, 117599, Singapore; Biolonic Currents Electromagnetic Pulsing Systems Laboratory (BICEPS), National University of Singapore, 117599, Singapore; Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 117593, Singapore; Healthy Longevity Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, 119228, Singapore; Nanomedicine Translational Research Programme, Centre for NanoMedicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; NUS Centre for Cancer Research, Yong Loo Lin School of Medicine, National University of Singapore, 117599, Singapore.
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9
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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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10
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Effect of weak alternating magnetic fields on planarian regeneration. Biochem Biophys Res Commun 2021; 592:7-12. [PMID: 35007847 DOI: 10.1016/j.bbrc.2021.12.096] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 12/25/2021] [Indexed: 11/23/2022]
Abstract
We investigated the effect of weak combined magnetic field (CMF) on stem cell proliferation and regeneration of the planarian Schmidtea mediterranea. CMF parameters were set in accordance with Valery Lednev's theory of magnetic parametric resonance. It was shown that CMF with an amplitude of 74 μT and a frequency of 30 Hz accelerated the growth of the planarian head blastema by 25%. Alterations of the frequency in range from 27 to 33 Hz led to a complete disappearance of the effect. A further decrease in the CMF frequency inhibited regeneration. The maximum inhibition (24%) was observed at a frequency of 16 Hz. A further decrease in the CMF frequency (down to 13 Hz) led to disappearance of the described effect. Regeneration rate changes under the CMF are influenced by alterations in stem cell mitotic activity, which in turn depends on the wound-induced gene expression level. Thus, the CMF, preset in accordance to the Lednev's theory, can specifically influence the expression of regeneration-related genes and regeneration itself, what can find biomedical applications.
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11
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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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12
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Khan MW, Juutilainen J, Naarala J, Roivainen P. Residential extremely low frequency magnetic fields and skin cancer. Occup Environ Med 2021; 79:49-54. [PMID: 34593542 DOI: 10.1136/oemed-2021-107776] [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: 05/25/2021] [Accepted: 09/07/2021] [Indexed: 11/03/2022]
Abstract
OBJECTIVE Photoinduced radical reactions have a fundamental role in skin cancer induced by ultraviolet radiation, and changes in radical reactions have also been proposed as a mechanism for the putative carcinogenic effects of extremely low frequency (ELF) magnetic fields (MFs). We assessed the association of melanoma and squamous cell carcinoma with residential MF exposure. METHODS All cohort members had lived in buildings with indoor transformer stations (TSs) during the period from 1971 to 2016. MF exposure was assessed based on apartment location. Out of the 225 492 individuals, 8617 (149 291 person-years of follow-up) living in apartments next to TSs were considered as exposed, while individuals living on higher floors of the same buildings were considered as referents. Associations between MF exposure and skin cancers were examined using Cox proportional hazard models. RESULTS The HR for MF exposure ≥6 month was 1.05 (95% CI 0.72 to 1.53) for melanoma and 0.94 (95% CI 0.55 to 1.61) for squamous cell carcinoma. Analysis of the age at the start of residence showed an elevated HR (2.55, 95% CI 1.15 to 5.69) for melanoma among those who lived in the apartments when they were less than 15 years old. This finding was based on seven exposed cases. CONCLUSIONS The results of this study suggested an association between childhood ELF MF exposure and adult melanoma. This is in agreement with previous findings suggesting that the carcinogenic effects of ELF MFs may be associated particularly with childhood exposure.
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Affiliation(s)
- Muhammad Waseem Khan
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland.,Department of Biotechnology, Balochistan University of Information Technology, Engineering and Management Sciences, Quetta, Pakistan
| | - Jukka Juutilainen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - Jonne Naarala
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - Päivi Roivainen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland .,Radiation and Nuclear Safety Authority (STUK), Helsinki, Finland
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13
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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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14
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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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15
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Abstract
We demonstrate, by direct, single-cell imaging kinetic measurements, that endogenous autofluorescence in HeLa cells is sensitive to the application of external magnetic fields of 25 mT and less. We provide spectroscopic and mechanistic evidence that our findings can be explained in terms of magnetic field effects on photoinduced electron transfer reactions to flavins, through the radical pair mechanism. The observed magnetic field dependence is consistent with a triplet-born radical pair and a B1/2 value of 18.0 mT with a saturation value of 3.7%.
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16
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Amplification of weak magnetic field effects on oscillating reactions. Sci Rep 2021; 11:9615. [PMID: 33953230 PMCID: PMC8100163 DOI: 10.1038/s41598-021-88871-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Accepted: 04/19/2021] [Indexed: 11/30/2022] Open
Abstract
We explore the possibility that chemical feedback and autocatalysis in oscillating chemical reactions could amplify weak magnetic field effects on the rate constant of one of the constituent reactions, assumed to proceed via a radical pair mechanism. Using the Brusselator model oscillator, we find that the amplitude of limit cycle oscillations in the concentrations of reaction intermediates can be extraordinarily sensitive to minute changes in the rate constant of the initiation step. The relevance of such amplification to biological effects of 50/60 Hz electromagnetic fields is discussed.
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17
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Keens RH, Sampson C, Kattnig DR. How symmetry-breaking can amplify the magnetosensitivity of dipolarly coupled n-radical systems. J Chem Phys 2021; 154:094101. [PMID: 33685169 DOI: 10.1063/5.0041552] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
In systems of more than two reactive radicals, the radical recombination probability can be magnetosensitive due to the mere effect of the inter-radical electron-electron dipolar coupling. Here, we demonstrate that this principle, previously established for three-radical systems, generalizes to n-radical systems. We focus on radical systems in the plane and explore the effects of symmetry, in particular its absence, on the associated magnetic field effects of the recombination yield. We show, by considering regular configurations and slightly distorted geometries, that the breaking of geometric symmetry can lead to an enhancement of the magnetosensitivity of these structures. Furthermore, we demonstrate the presence of effects at low-field that are abolished in the highly symmetric case. This could be important to the understanding of the behavior of radicals in biological environments in the presence of weak magnetic fields comparable to the Earth's, as well as the construction of high-precision quantum sensing devices.
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Affiliation(s)
- Robert H Keens
- Living Systems Institute and Department of Physics, University of Exeter, Stocker Road, Exeter, Devon EX4 4QD, United Kingdom
| | - Chris Sampson
- Living Systems Institute and Department of Physics, University of Exeter, Stocker Road, Exeter, Devon EX4 4QD, United Kingdom
| | - 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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18
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Konowalczyk M, Foster Vander Elst O, Storey JG. Development of lock-in based overtone modulated MARY spectroscopy for detection of weak magnetic field effects. Phys Chem Chem Phys 2021; 23:1273-1284. [PMID: 33355552 DOI: 10.1039/d0cp04814c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Modulated magnetically altered reaction yield (ModMARY) spectroscopy is a derivative variant of fluorescence detected magnetic field effect measurement, where the applied magnetic field has both a constant and a modulated component. As in many derivative spectroscopy techniques, the signal to noise ratio scales with the magnitude of the modulation. High modulation amplitudes, however, distort the signal and can obscure small features of the measured spectrum. In order to detect weak magnetic field effects (including the low field effect) a balance of the two has to be found. In this work we look in depth at the origin of the distortion of the MARY signal by field modulation. We then present an overtone detection scheme, as well as a data analysis method which allows for correct fitting of both harmonic and overtone signals of the modulation broadened MARY data. This allows us to robustly reconstruct the underlying MARY curve at different modulation depths. To illustrate the usefulness of the technique, we show measurements and analysis of a well known magnetosensitive system of pyrene/1,3-dicyanobenzene (Py/DCB). The measurements of first (h1) and second (h2) harmonic spectra are performed at different modulation depths for both natural isotopic abundance (PyH10), and perdeuterated (PyD10) pyrene samples.
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Affiliation(s)
- Marcin Konowalczyk
- Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory, Oxford OX1 3QZ, UK. and Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, Oxford OX1 3QR, UK
| | | | - Jonathan G Storey
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, Oxford OX1 3QR, UK
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19
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Wong SY, Solov'yov IA, Hore PJ, Kattnig DR. Nuclear polarization effects in cryptochrome-based magnetoreception. J Chem Phys 2021; 154:035102. [PMID: 33499614 DOI: 10.1063/5.0038947] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The mechanism of the magnetic compass sense of migratory songbirds is thought to involve magnetically sensitive chemical reactions of light-induced radical pairs in cryptochrome proteins located in the birds' eyes. However, it is not yet clear whether this mechanism would be sensitive enough to form the basis of a viable compass. In the present work, we report spin dynamics simulations of models of cryptochrome-based radical pairs to assess whether accumulation of nuclear spin polarization in multiple photocycles could lead to significant enhancements in the sensitivity with which the proteins respond to the direction of the geomagnetic field. Although buildup of nuclear polarization appears to offer sensitivity advantages in the more idealized model systems studied, we find that these enhancements do not carry over to conditions that more closely resemble the situation thought to exist in vivo. On the basis of these simulations, we conclude that buildup of nuclear polarization seems unlikely to be a source of significant improvements in the performance of cryptochrome-based radical pair magnetoreceptors.
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Affiliation(s)
- Siu Ying Wong
- Institut für Physik, Carl-von-Ossietzky Universität Oldenburg, 26111 Oldenburg, Germany
| | - Ilia A Solov'yov
- Institut für Physik, Carl-von-Ossietzky Universität Oldenburg, 26111 Oldenburg, Germany
| | - P J Hore
- Department of Chemistry, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - Daniel R Kattnig
- Living Systems Institute and Department of Physics, University of Exeter, Exeter EX4 4QD, United Kingdom
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20
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Behera RK, Sau A, Mishra L, Mondal S, Bera K, Kumar S, Basu S, Sarangi MK. Metal nanoparticle alters adenine induced charge transfer kinetics of vitamin K3 in magnetic field. Sci Rep 2020; 10:18454. [PMID: 33116189 PMCID: PMC7595215 DOI: 10.1038/s41598-020-75262-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 09/28/2020] [Indexed: 01/05/2023] Open
Abstract
In this article, we highlight the alterations in the photoinduced electron transfer (ET) and hydrogen atom transfer (HAT) pathways between an anti-tumor drug vitamin-K3 (MQ) and a nucleobase adenine (ADN) in the presence of gold (Au) and iron (Fe) nanoparticles (NPs). Inside the confined micellar media, with laser flash photolysis corroborated with an external magnetic field (MF), we have detected the transient geminate radicals of MQ and ADN, photo-generated through ET and HAT. We observe that the presence of AuNP on the MQ-ADN complex (AuMQ-ADN) assists HAT by limiting the ET channel, on the other hand, FeNP on the MQ-ADN complex (FeMQ-ADN) mostly favors a facile PET. We hypothesize that through selective interactions of the ADN molecules with AuNP and MQ molecules with FeNP, a preferential HAT and PET process is eased. The enhanced HAT and PET have been confirmed by the escape yields of radical intermediates by time-resolved transient absorption spectroscopy in the presence of MF.
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Affiliation(s)
| | - Abhishek Sau
- Chemical Sciences Division, Saha Institute of Nuclear Physics, Kolkata, India.,Department of Molecular and Cellular Medicine, Texas A&M University, College Station, USA
| | - Leepsa Mishra
- Department of Physics, Indian Institute of Technology Patna, Patna, India
| | - Sankalan Mondal
- Department of Physics, Indian Institute of Technology Patna, Patna, India
| | - Kallol Bera
- Chemical Sciences Division, Saha Institute of Nuclear Physics, Kolkata, India.,Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, USA
| | - Satish Kumar
- Department of Physics, Indian Institute of Technology Patna, Patna, India
| | - Samita Basu
- Chemical Sciences Division, Saha Institute of Nuclear Physics, Kolkata, India
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21
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Déjean V, Konowalczyk M, Gravell J, Golesworthy MJ, Gunn C, Pompe N, Foster Vander Elst O, Tan KJ, Oxborrow M, Aarts DGAL, Mackenzie SR, Timmel CR. Detection of magnetic field effects by confocal microscopy. Chem Sci 2020; 11:7772-7781. [PMID: 34094150 PMCID: PMC8163210 DOI: 10.1039/d0sc01986k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Certain pairs of paramagnetic species generated under conservation of total spin angular momentum are known to undergo magnetosensitive processes. Two prominent examples of systems exhibiting these so-called magnetic field effects (MFEs) are photogenerated radical pairs created from either singlet or triplet molecular precursors, and pairs of triplet states generated by singlet fission. Here, we showcase confocal microscopy as a powerful technique for the investigation of such phenomena. We first characterise the instrument by studying the field-sensitive chemistry of two systems in solution: radical pairs formed in a cryptochrome protein and the flavin mononucleotide/hen egg-white lysozyme model system. We then extend these studies to single crystals. Firstly, we report temporally and spatially resolved MFEs in flavin-doped lysozyme single crystals. Anisotropic magnetic field effects are then reported in tetracene single crystals. Finally, we discuss the future applications of confocal microscopy for the study of magnetosensitive processes with a particular focus on the cryptochrome-based chemical compass believed to lie at the heart of animal magnetoreception. Confocal microscopy is showcased as a powerful technique for the measurement of spatiotemporally-resolved magnetic field effects in both solutions and single crystals.![]()
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Affiliation(s)
- Victoire Déjean
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory Oxford OX1 3QR UK
| | - Marcin Konowalczyk
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory Oxford OX1 3QR UK .,Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory Oxford OX1 3QZ UK
| | - Jamie Gravell
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory Oxford OX1 3QR UK
| | - Matthew J Golesworthy
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory Oxford OX1 3QR UK
| | - Catlin Gunn
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory Oxford OX1 3QR UK
| | - Nils Pompe
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory Oxford OX1 3QR UK
| | | | - Ke-Jie Tan
- Department of Materials, Imperial College London London SW7 2AZ UK
| | - Mark Oxborrow
- Department of Materials, Imperial College London London SW7 2AZ UK
| | - Dirk G A L Aarts
- Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory Oxford OX1 3QZ UK
| | - Stuart R Mackenzie
- Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory Oxford OX1 3QZ UK
| | - Christiane R Timmel
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory Oxford OX1 3QR UK .,Centre for Advanced Electron Spin Resonance (CAESR), Department of Chemistry, University of Oxford Oxford OX1 3QR UK
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22
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Kim D, Lee YJ, Ahn DH, Song JW, Seo J, Lee H. Peptoid-Conjugated Magnetic Field-Sensitive Exciplex System at High and Low Solvent Polarities. J Phys Chem Lett 2020; 11:4668-4677. [PMID: 32441939 DOI: 10.1021/acs.jpclett.0c00636] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The magnetic field effect (MFE) in exciplex emission (ExE) has been studied for decades, but it has been observed to occur only in solvents with a limited range of polarity. This limitation is mainly due to the reversible interconversion collapse between two quenching products of the photoinduced electron transfer, the exciplex and magnetic field-sensitive radical ion pair (RIP) beyond that polarity range. In a nonpolar solvent, the formation of RIPs is suppressed, whereas in a polar solvent, the probability of their re-encounter forming the exciplexes decreases. In this study, we developed new exciplex-forming (phenyl-phenanthrene)-(phenyl-N,N-dimethylaniline)-peptoid conjugates (PhD-PCs) to overcome this limitation. The well-defined peptoid structure allows precise control of the distance and the relative orientation between two conjugated moieties. Steady-state and time-resolved spectroscopic data indicate that the PhD-PCs can maintain the reversibility, which allows MFEs in ExE regardless of the solvent polarity. Subtle differences between the ExEs of the PhD-PCs were observed and explained by their exciplex geometries obtained through time-dependent density functional theory (TD-DFT) calculations.
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Affiliation(s)
- Dongkyum Kim
- Department of Chemistry, Gwangju Institute of Science and Technology (GIST), 123 Cheomdan Gwagiro, Buk-gu, Gwangju 61005, Republic of Korea
| | - Yen Jea Lee
- Department of Chemistry, Gwangju Institute of Science and Technology (GIST), 123 Cheomdan Gwagiro, Buk-gu, Gwangju 61005, Republic of Korea
| | - Dae-Hwan Ahn
- Department of Chemistry Education, Daegu University, Gyeongsan-si 113-8656, Republic of Korea
| | - Jong-Won Song
- Department of Chemistry Education, Daegu University, Gyeongsan-si 113-8656, Republic of Korea
| | - Jiwon Seo
- Department of Chemistry, Gwangju Institute of Science and Technology (GIST), 123 Cheomdan Gwagiro, Buk-gu, Gwangju 61005, Republic of Korea
| | - Hohjai Lee
- Department of Chemistry, Gwangju Institute of Science and Technology (GIST), 123 Cheomdan Gwagiro, Buk-gu, Gwangju 61005, Republic of Korea
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23
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Lindoy LP, Fay TP, Manolopoulos DE. Quantum mechanical spin dynamics of a molecular magnetoreceptor. J Chem Phys 2020; 152:164107. [DOI: 10.1063/5.0006411] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Lachlan P. Lindoy
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Thomas P. Fay
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - David E. Manolopoulos
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
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24
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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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25
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Vanderstraeten J, Gailly P, Malkemper EP. Light entrainment of retinal biorhythms: cryptochrome 2 as candidate photoreceptor in mammals. Cell Mol Life Sci 2020; 77:875-884. [PMID: 31982933 PMCID: PMC11104904 DOI: 10.1007/s00018-020-03463-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 01/08/2020] [Accepted: 01/14/2020] [Indexed: 12/31/2022]
Abstract
The mechanisms that synchronize the biorhythms of the mammalian retina with the light/dark cycle are independent of those synchronizing the rhythms in the central pacemaker, the suprachiasmatic nucleus. The identity of the photoreceptor(s) responsible for the light entrainment of the retina of mammals is still a matter of debate, and recent studies have reported contradictory results in this respect. Here, we suggest that cryptochromes (CRY), in particular CRY 2, are involved in that light entrainment. CRY are highly conserved proteins that are a key component of the cellular circadian clock machinery. In plants and insects, they are responsible for the light entrainment of these biorhythms, mediated by the light response of their flavin cofactor (FAD). In mammals, however, no light-dependent role is currently assumed for CRY in light-exposed tissues, including the retina. It has been reported that FAD influences the function of mammalian CRY 2 and that human CRY 2 responds to light in Drosophila, suggesting that mammalian CRY 2 keeps the ability to respond to light. Here, we hypothesize that CRY 2 plays a role in the light entrainment of retinal biorhythms, at least in diurnal mammals. Indeed, published data shows that the light intensity dependence and the wavelength sensitivity commonly reported for that light entrainment fits the light sensitivity and absorption spectrum of light-responsive CRY. We propose experiments to test our hypothesis and to further explore the still-pending question of the function of CRY 2 in the mammalian retina.
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Affiliation(s)
- Jacques Vanderstraeten
- Faculty of Medicine, School of Public Health, Environmental and Work Health Research Center, Université Libre de Bruxelles, CP593, Route de Lennik, 808, 1070, Brussels, Belgium.
- , Avenue Constant Montald, 11, 1200, Brussels, Belgium.
| | - Philippe Gailly
- Faculty of Medicine, Institute of Neuroscience (IONS), Cellular and Molecular Pole (CEMO), Catholic University of Louvain, Avenue Mounier 53/B1.53.17, 1200, Brussels, Belgium
| | - E Pascal Malkemper
- Center of Advanced European Studies and Research (CAESAR), Ludwig-Erhard-Allee 2, Bonn, 53175, Germany
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26
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Pan H, Jiang X, Wang X, Wang Q, Wang M, Shen Y. Effective Magnetic Field Regulation of the Radical Pair Spin States in Electrocatalytic CO 2 Reduction. J Phys Chem Lett 2020; 11:48-53. [PMID: 31821005 DOI: 10.1021/acs.jpclett.9b03146] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Regulation of the radical pair spin states allows effective optimization of the electrocatalytic CO2 reduction reaction. This study for the first time reports an experimental observation of significantly boosting the catalytic activity of tin nanoparticle catalysts by an external magnetic field for electrocatalytic CO2 reduction to formate/formic acid. We reveal that enhancing the amount of singlet radical pairs via magnetic field-facilitated triplet → singlet spin evolution can significantly increase the catalytic activity toward an efficient overall electrochemical CO2 reduction reaction. When a common Sn nanoparticle electrode was used as an example, in a constant applied magnetic field (about 0.9 T), the yield of formic acid can be nearly doubled compared to that of zero magnetic field. This finding suggests the merits of radical pair spin states in the electron-transfer process and paves the way toward high formate production in electrocatalytic reduction of CO2.
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Affiliation(s)
- Haiping Pan
- Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information , Huazhong University of Science and Technology , Wuhan 430074 , China
- School of Physics and Optoelectronic Engineering , Foshan University , Foshan , Guangdong 528000 , China
| | - XingXing Jiang
- Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information , Huazhong University of Science and Technology , Wuhan 430074 , China
| | - Xikui Wang
- Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information , Huazhong University of Science and Technology , Wuhan 430074 , China
| | - Qinglong Wang
- Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information , Huazhong University of Science and Technology , Wuhan 430074 , China
| | - Mingkui Wang
- Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information , Huazhong University of Science and Technology , Wuhan 430074 , China
| | - Yan Shen
- Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information , Huazhong University of Science and Technology , Wuhan 430074 , China
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27
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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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28
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Yap JLY, Tai YK, Fröhlich J, Fong CHH, Yin JN, Foo ZL, Ramanan S, Beyer C, Toh SJ, Casarosa M, Bharathy N, Kala MP, Egli M, Taneja R, Lee CN, Franco-Obregón A. Ambient and supplemental magnetic fields promote myogenesis via a TRPC1-mitochondrial axis: evidence of a magnetic mitohormetic mechanism. FASEB J 2019; 33:12853-12872. [PMID: 31518158 DOI: 10.1096/fj.201900057r] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
We show that both supplemental and ambient magnetic fields modulate myogenesis. A lone 10 min exposure of myoblasts to 1.5 mT amplitude supplemental pulsed magnetic fields (PEMFs) accentuated in vitro myogenesis by stimulating transient receptor potential (TRP)-C1-mediated calcium entry and downstream nuclear factor of activated T cells (NFAT)-transcriptional and P300/CBP-associated factor (PCAF)-epigenetic cascades, whereas depriving myoblasts of ambient magnetic fields slowed myogenesis, reduced TRPC1 expression, and silenced NFAT-transcriptional and PCAF-epigenetic cascades. The expression levels of peroxisome proliferator-activated receptor γ coactivator 1α, the master regulator of mitochondriogenesis, was also enhanced by brief PEMF exposure. Accordingly, mitochondriogenesis and respiratory capacity were both enhanced with PEMF exposure, paralleling TRPC1 expression and pharmacological sensitivity. Clustered regularly interspaced short palindromic repeats-Cas9 knockdown of TRPC1 precluded proliferative and mitochondrial responses to supplemental PEMFs, whereas small interfering RNA gene silencing of TRPM7 did not, coinciding with data that magnetoreception did not coincide with the expression or function of other TRP channels. The aminoglycoside antibiotics antagonized and down-regulated TRPC1 expression and, when applied concomitantly with PEMF exposure, attenuated PEMF-stimulated calcium entry, mitochondrial respiration, proliferation, differentiation, and epigenetic directive in myoblasts, elucidating why the developmental potential of magnetic fields may have previously escaped detection. Mitochondrial-based survival adaptations were also activated upon PEMF stimulation. Magnetism thus deploys an authentic myogenic directive that relies on an interplay between mitochondria and TRPC1 to reach fruition.-Yap, J. L. Y., Tai, Y. K., Fröhlich, J., Fong, C. H. H., Yin, J. N., Foo, Z. L., Ramanan, S., Beyer, C., Toh, S. J., Casarosa, M., Bharathy, N., Kala, M. P., Egli, M., Taneja, R., Lee, C. N., Franco-Obregón, A. Ambient and supplemental magnetic fields promote myogenesis via a TRPC1-mitochondrial axis: evidence of a magnetic mitohormetic mechanism.
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Affiliation(s)
- Jasmine Lye Yee Yap
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,BioIonic Currents Electromagnetic Pulsing Systems (BICEPS) Laboratory, National University of Singapore, Singapore
| | - Yee Kit Tai
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,BioIonic Currents Electromagnetic Pulsing Systems (BICEPS) Laboratory, National University of Singapore, Singapore
| | - Jürg Fröhlich
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Institute for Electromagnetic Fields, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland
| | - Charlene Hui Hua Fong
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,BioIonic Currents Electromagnetic Pulsing Systems (BICEPS) Laboratory, National University of Singapore, Singapore
| | - Jocelyn Naixin Yin
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,BioIonic Currents Electromagnetic Pulsing Systems (BICEPS) Laboratory, National University of Singapore, Singapore
| | - Zi Ling Foo
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,BioIonic Currents Electromagnetic Pulsing Systems (BICEPS) Laboratory, National University of Singapore, Singapore
| | - Sharanya Ramanan
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,BioIonic Currents Electromagnetic Pulsing Systems (BICEPS) Laboratory, National University of Singapore, Singapore
| | - Christian Beyer
- Institute for Electromagnetic Fields, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland.,Centre Suisse d'Électronique et de Microtechnique (CSEM SA), Neuchâtel, Switzerland
| | - Shi Jie Toh
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,BioIonic Currents Electromagnetic Pulsing Systems (BICEPS) Laboratory, National University of Singapore, Singapore
| | - Marco Casarosa
- Department of Experimental and Clinical Biomedical Sciences Mario Serio, University of Florence, Florence, Italy
| | - Narendra Bharathy
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Children's Cancer Therapy Development Institute, Beaverton, Oregon, USA
| | - Monica Palanichamy Kala
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Marcel Egli
- Institute of Medical Engineering, Lucerne University of Applied Sciences and Arts, Hergiswil, Switzerland; and
| | - Reshma Taneja
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Chuen Neng Lee
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Institute for Health Innovation and Technology, iHealthtech, National University of Singapore, Singapore
| | - Alfredo Franco-Obregón
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,BioIonic Currents Electromagnetic Pulsing Systems (BICEPS) Laboratory, National University of Singapore, Singapore.,Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Institute for Health Innovation and Technology, iHealthtech, National University of Singapore, Singapore
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29
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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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30
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Sampson C, Keens RH, Kattnig DR. On the magnetosensitivity of lipid peroxidation: two- versus three-radical dynamics. Phys Chem Chem Phys 2019; 21:13526-13538. [PMID: 31210238 DOI: 10.1039/c9cp01746a] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
We present a theoretical analysis of the putative magnetosensitivity of lipid peroxidation. We focus on the widely accepted radical pair mechanism (RPM) and a recently suggested idea based on spin dynamics induced in three-radical systems by the mutual electron-electron dipolar coupling (D3M). We show that, contrary to claims in the literature, lipid peroxides, the dominant chain carriers of the autoxidation process, have associated non-zero hyperfine coupling interactions. This suggests that their recombination could, in principle, be magnetosensitive due to the RPM. While the RPM indeed goes a long way to explaining magnetosensitivity in these systems, we show that the simultaneous interaction of three peroxyl radicals via the D3M can achieve larger magnetic field effects (MFE), even if the third radical is remote from the recombining radical pair. For randomly oriented three-radical systems, the D3M induces a low-field effect comparable to that of the RPM. The mechanism furthermore immunizes the spin dynamics to the presence of large exchange coupling interactions in the recombining radical pair, thereby permitting much larger MFE at magnetic field intensities comparable to the geomagnetic field than would be expected for the RPM. Based on these characteristics, we suggest that the D3M could be particularly relevant for MFE at low fields, provided that the local radical concentration is sufficient to allow for three-spin radical correlations. Eventually, our observations suggest that MFEs could intricately depend on radical concentration and larger effects could ensue under conditions of oxidative stress.
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Affiliation(s)
- Chris Sampson
- Living Systems Institute and Department of Physics, University of Exeter, Stocker Road, Exeter, Devon, EX4 4QD, UK.
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31
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Hore PJ. Upper bound on the biological effects of 50/60 Hz magnetic fields mediated by radical pairs. eLife 2019; 8:44179. [PMID: 30801245 PMCID: PMC6417859 DOI: 10.7554/elife.44179] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 02/02/2019] [Indexed: 01/02/2023] Open
Abstract
Prolonged exposure to weak (~1 μT) extremely-low-frequency (ELF, 50/60 Hz) magnetic fields has been associated with an increased risk of childhood leukaemia. One of the few biophysical mechanisms that might account for this link involves short-lived chemical reaction intermediates known as radical pairs. In this report, we use spin dynamics simulations to derive an upper bound of 10 parts per million on the effect of a 1 μT ELF magnetic field on the yield of a radical pair reaction. By comparing this figure with the corresponding effects of changes in the strength of the Earth’s magnetic field, we conclude that if exposure to such weak 50/60 Hz magnetic fields has any effect on human biology, and results from a radical pair mechanism, then the risk should be no greater than travelling a few kilometres towards or away from the geomagnetic north or south pole.
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Affiliation(s)
- P J Hore
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, Oxford, United Kingdom
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32
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Pooam M, Arthaut LD, Burdick D, Link J, Martino CF, Ahmad M. Magnetic sensitivity mediated by the Arabidopsis blue-light receptor cryptochrome occurs during flavin reoxidation in the dark. PLANTA 2019; 249:319-332. [PMID: 30194534 DOI: 10.1007/s00425-018-3002-y] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 08/29/2018] [Indexed: 05/20/2023]
Abstract
Arabidopsis cryptochrome mediates responses to magnetic fields that have been applied in the absence of light, consistent with flavin reoxidation as the primary detection mechanism. Cryptochromes are highly conserved blue-light-absorbing flavoproteins which have been linked to the perception of electromagnetic stimuli in numerous organisms. These include sensing the direction of the earth's magnetic field in migratory birds and the intensity of magnetic fields in insects and plants. When exposed to light, cryptochromes undergo flavin reduction/reoxidation redox cycles leading to biological activation which generate radical pairs thought to be the basis for magnetic sensitivity. However, the nature of the magnetically sensitive radical pairs and the steps at which they act during the cryptochrome redox cycle are currently a matter of debate. Here, we investigate the response of Arabidopsis cryptochrome-1 in vivo to a static magnetic field of 500 μT (10 × earth's field) using both plant growth and light-dependent phosphorylation as an assay. Cryptochrome responses to light were enhanced by the magnetic field, as indicated by increased inhibition of hypocotyl elongation and increased cryptochrome phosphorylation. However, when light and dark intervals were given intermittently, a plant response to the magnetic field was observed even when the magnetic field was given exclusively during the dark intervals between light exposures. This indicates that the magnetically sensitive reaction step in the cryptochrome photocycle must occur during flavin reoxidation, and likely involves the formation of reactive oxygen species.
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Affiliation(s)
- Marootpong Pooam
- Sorbonne Universités, CNRS, UMR8256, IBPS, Photobiology Research Group, 7 Quai St. Bernard, 75005, Paris, France
| | - Louis-David Arthaut
- Sorbonne Universités, CNRS, UMR8256, IBPS, Photobiology Research Group, 7 Quai St. Bernard, 75005, Paris, France
| | - Derek Burdick
- Sorbonne Universités, CNRS, UMR8256, IBPS, Photobiology Research Group, 7 Quai St. Bernard, 75005, Paris, France
- Xavier University, 3800 Victory Parkway, Cincinnati, OH, 45207, USA
| | - Justin Link
- Xavier University, 3800 Victory Parkway, Cincinnati, OH, 45207, USA
| | - Carlos F Martino
- Department of Biomedical Engineering, Florida Institute of Technology, 150W University Blvd, Melbourne, FL, 32901, USA
| | - Margaret Ahmad
- Sorbonne Universités, CNRS, UMR8256, IBPS, Photobiology Research Group, 7 Quai St. Bernard, 75005, Paris, France.
- Xavier University, 3800 Victory Parkway, Cincinnati, OH, 45207, USA.
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33
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Sannikova VA, Davydova MP, Sherin PS, Babenko SV, Korolev VV, Stepanov AA, Nikul'shin PV, Kalneus EV, Vasilevsky SF, Benassi E, Melnikov AR. Determination of Hyperfine Coupling Constants of Fluorinated Diphenylacetylene Radical Anions by Magnetic Field-Affected Reaction Yield Spectroscopy. J Phys Chem A 2019; 123:505-516. [PMID: 30566354 DOI: 10.1021/acs.jpca.8b10306] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Magnetic field-affected reaction yield (MARY) spectroscopy is a spin chemistry technique for detecting short-lived radical ions. Having sensitivity to transient species with lifetimes as short as nanoseconds, MARY spectroscopy usually does not provide detailed information on their magnetic resonance parameters, except for simple systems with equivalent magnetic nuclei. In this work, the radical anions of two fluorinated diphenylacetylene derivatives with nonequivalent magnetic nuclei and unknown hyperfine coupling constants ( AHF) were investigated by MARY spectroscopy. The MARY spectra were found to be resolved and have resonance lines in nonzero magnetic fields, which are determined by the AHF values. Simple relationships between the positions of resonance MARY lines and the AHF values were established from the analysis of the different Hamiltonian block contributions to the MARY spectrum. The obtained experimental AHF values are in agreement with the results of quantum chemical calculations at the density functional theory level.
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Affiliation(s)
- Victoria A Sannikova
- Institute of Chemical Kinetics and Combustion SB RAS , 3, Institutskaya Str. , 630090 Novosibirsk , Russian Federation.,Novosibirsk State University , 2, Pirogova Str. , 630090 Novosibirsk , Russian Federation
| | - Maria P Davydova
- Institute of Chemical Kinetics and Combustion SB RAS , 3, Institutskaya Str. , 630090 Novosibirsk , Russian Federation.,A.V. Nikolaev Institute of Inorganic Chemistry SB RAS , 3, Akademika Lavrentieva Ave. , 630090 Novosibirsk , Russian Federation
| | - Peter S Sherin
- Novosibirsk State University , 2, Pirogova Str. , 630090 Novosibirsk , Russian Federation.,International Tomography Center , 3a, Institutskaya Str. , 630090 Novosibirsk , Russian Federation
| | - Simon V Babenko
- Institute of Chemical Kinetics and Combustion SB RAS , 3, Institutskaya Str. , 630090 Novosibirsk , Russian Federation
| | - Valeri V Korolev
- Institute of Chemical Kinetics and Combustion SB RAS , 3, Institutskaya Str. , 630090 Novosibirsk , Russian Federation
| | - Alexander A Stepanov
- Institute of Chemical Kinetics and Combustion SB RAS , 3, Institutskaya Str. , 630090 Novosibirsk , Russian Federation.,Novosibirsk State University , 2, Pirogova Str. , 630090 Novosibirsk , Russian Federation
| | - Pavel V Nikul'shin
- N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS , 9, Akademika Lavrentieva Ave. , 630090 Novosibirsk , Russian Federation
| | - Evgeny V Kalneus
- Institute of Chemical Kinetics and Combustion SB RAS , 3, Institutskaya Str. , 630090 Novosibirsk , Russian Federation
| | - Sergei F Vasilevsky
- Institute of Chemical Kinetics and Combustion SB RAS , 3, Institutskaya Str. , 630090 Novosibirsk , Russian Federation.,Novosibirsk State University , 2, Pirogova Str. , 630090 Novosibirsk , Russian Federation
| | - Enrico Benassi
- Novosibirsk State University , 2, Pirogova Str. , 630090 Novosibirsk , Russian Federation.,Department of Chemistry , Hexi University , 734000 Zhangye , China
| | - Anatoly R Melnikov
- Institute of Chemical Kinetics and Combustion SB RAS , 3, Institutskaya Str. , 630090 Novosibirsk , Russian Federation.,Novosibirsk State University , 2, Pirogova Str. , 630090 Novosibirsk , Russian Federation
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34
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Vanderstraeten J, Gailly P, Malkemper EP. Corrigendum: Low-Light Dependence of the Magnetic Field Effect on Cryptochromes: Possible Relevance to Plant Ecology. FRONTIERS IN PLANT SCIENCE 2018; 9:1459. [PMID: 30310387 PMCID: PMC6173225 DOI: 10.3389/fpls.2018.01459] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 09/12/2018] [Indexed: 06/08/2023]
Abstract
[This corrects the article DOI: 10.3389/fpls.2018.00121.].
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Affiliation(s)
- Jacques Vanderstraeten
- Environmental and Work Health Research Center, School of Public Health, Université Libre de Bruxelles, Brussels, Belgium
| | - Philippe Gailly
- Institute of Neuroscience, Université Catholique de Louvain, Brussels, Belgium
| | - E. Pascal Malkemper
- Department of General Zoology, Faculty of Biology, University of Duisburg-Essen, Essen, Germany
- Department of Wildlife Management, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Praha, Czechia
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35
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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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36
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Keens RH, Bedkihal S, Kattnig DR. Magnetosensitivity in Dipolarly Coupled Three-Spin Systems. PHYSICAL REVIEW LETTERS 2018; 121:096001. [PMID: 30230901 DOI: 10.1103/physrevlett.121.096001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Indexed: 06/08/2023]
Abstract
The radical pair mechanism is a canonical model for the magnetosensitivity of chemical reaction processes. The key ingredient of this model is the hyperfine interaction that induces a coherent mixing of singlet and triplet electron spin states in pairs of radicals, thereby facilitating magnetic field effects (MFEs) on reaction yields through spin-selective reaction channels. We show that the hyperfine interaction is not a categorical requirement to realize the sensitivity of radical reactions to weak magnetic fields. We propose that, in systems comprising three instead of two radicals, dipolar interactions provide an alternative pathway for MFEs. By considering the role of symmetries and energy level crossings, we present a model that demonstrates a directional sensitivity to fields weaker than the geomagnetic field and remarkable spikes in the reaction yield as a function of the magnetic field intensity; these effects can moreover be tuned by the exchange interaction. Our results further the current understanding of the effects of weak magnetic fields on chemical reactions, could pave the way to a clearer understanding of the mysteries of magnetoreception and other biological MFEs and motivate the design of quantum sensors. Further still, this phenomenon will affect spin systems used in quantum information processing in the solid state and may also be applicable to spintronics.
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Affiliation(s)
- Robert H Keens
- Living Systems Institute and Department of Physics, University of Exeter, Stocker Road, Exeter, Devon, EX4 4QD, United Kingdom
| | - Salil Bedkihal
- Living Systems Institute and Department of Physics, University of Exeter, Stocker Road, Exeter, Devon, EX4 4QD, United Kingdom
| | - 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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37
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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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38
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Zeng Z, Wei J, Liu Y, Zhang W, Mabe T. Magnetoreception of Photoactivated Cryptochrome 1 in Electrochemistry and Electron Transfer. ACS OMEGA 2018; 3:4752-4759. [PMID: 31458694 PMCID: PMC6641772 DOI: 10.1021/acsomega.8b00645] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Accepted: 04/23/2018] [Indexed: 06/10/2023]
Abstract
Cryptochromes are flavoproteins whose photochemistry is important for crucial functions associated with phototropism and circadian clocks. In this report, we, for the first time, observed a magnetic response of the cryptochrome 1 (CRY1) immobilized at a gold electrode with illumination of blue light. These results present the magnetic field-enhanced photoinduced electron transfer of CRY1 to the electrode by voltammetry, exhibiting magnetic responsive rate constant and electrical current changes. A mechanism of the electron transfer, which involves photoinduced radicals in the CRY, is sensitive to the weak magnetic field; and the long-lived free radical FAD•- is responsible for the detected electrochemical Faradaic current. As a photoreceptor, the finding of a 5.7% rate constant change in electron transfer corresponding to a 50 μT magnetic field may be meaningful in regulation of magnetic field signaling and circadian clock function under an electromagnetic field.
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39
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Antill LM, Beardmore JP, Woodward JR. Time-resolved optical absorption microspectroscopy of magnetic field sensitive flavin photochemistry. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:023707. [PMID: 29495862 DOI: 10.1063/1.5011693] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 02/03/2018] [Indexed: 06/08/2023]
Abstract
The photochemical reactions of blue-light receptor proteins have received much attention due to their very important biological functions. In addition, there is also growing evidence that the one particular class of such proteins, the cryptochromes, may be associated with not only a biological photo-response but also a magneto-response, which may be responsible for the mechanism by which many animals can respond to the weak geomagnetic field. Therefore, there is an important scientific question over whether it is possible to directly observe such photochemical processes, and indeed the effects of weak magnetic fields thereon, taking place both in purified protein samples in vitro and in actual biochemical cells and tissues. For the former samples, the key lies in being able to make sensitive spectroscopic measurements on very small volumes of samples at potentially low protein concentrations, while the latter requires, in addition, spatially resolved measurements on length scales smaller than typical cellular components, i.e., sub-micron resolution. In this work, we discuss a two- and three-color confocal pump-probe microscopic approach to this question which satisfies these requirements and is thus useful for experimental measurements in both cases.
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Affiliation(s)
- Lewis M Antill
- Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, Japan
| | - Joshua P Beardmore
- Earth Dynamics Research Group, The Institute for Geoscience Research (TIGeR), Department of Applied Geology, Bentley, Curtin University, Perth 6102, Australia
| | - Jonathan R Woodward
- Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, Japan
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40
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Vanderstraeten J, Gailly P, Malkemper EP. Low-Light Dependence of the Magnetic Field Effect on Cryptochromes: Possible Relevance to Plant Ecology. FRONTIERS IN PLANT SCIENCE 2018; 9:121. [PMID: 29491873 PMCID: PMC5817061 DOI: 10.3389/fpls.2018.00121] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 01/23/2018] [Indexed: 05/20/2023]
Abstract
Various responses to static magnetic fields (MF) have been reported in plants, and it has been suggested that the geomagnetic field influences plant physiology. Accordingly, diverse mechanisms have been proposed to mediate MF effects in plants. The currently most probable sensor candidates are cryptochromes (Cry) which are sensitive to submillitesla MF. Here, we propose a quantitative approach of the MF effect on Cry depending on light intensity, and try to link it to a possible functional role for magnetic sensitivity in plants. Based on a theoretical evaluation and on a review of relevant data on Arabidopsis thaliana Cry 1, we point out that the MF effect on the signaling state of Cry, as well as the possible consequences of that effect on certain phenotypes (growth in particular) show parallel dependences on light intensity, being most prominent at low light levels. Based on these findings, we propose that Cry magnetosensitivity in plants could represent an ecological adaptation which regulates the amount of Cry signaling state under low light conditions. That hypothesis would preferentially be tested by studying sensitive and specific endpoints, such as the expression of clock proteins that are downregulated by Cry, but under light intensities lower than those used so far. Finally, we highlight that the low-light dependence of the MF effect described here could also apply to light-dependent functions of animal Cry, in particular magnetoreception which, from the present evaluation, would be based on the magnetic sensitivity of the photoreduction reaction, like in plants.
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Affiliation(s)
- Jacques Vanderstraeten
- Environmental and Work Health Research Center, School of Public Health, Université Libre de Bruxelles, Brussels, Belgium
- *Correspondence: Jacques Vanderstraeten
| | - Philippe Gailly
- Institute of Neuroscience, Université Catholique de Louvain, Brussels, Belgium
| | - E. Pascal Malkemper
- Department of General Zoology, Faculty of Biology, University of Duisburg-Essen, Essen, Germany
- Department of Wildlife Management, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Praha, Czechia
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41
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Mendive-Tapia D, Mangaud E, Firmino T, de la Lande A, Desouter-Lecomte M, Meyer HD, Gatti F. Multidimensional Quantum Mechanical Modeling of Electron Transfer and Electronic Coherence in Plant Cryptochromes: The Role of Initial Bath Conditions. J Phys Chem B 2017; 122:126-136. [DOI: 10.1021/acs.jpcb.7b10412] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- David Mendive-Tapia
- Institut
Charles Gerhardt Montpellier, UMR 5253, CNRS-UM-ENSCM, CTMM, Université Montpellier, CC 15001, Place Eugène Bataillon, 34095 Montpellier, France
- Theoretische
Chemie, Physikalisch-Chemisches Institut, Universität Heidelberg, INF 229, D-69120 Heidelberg, Germany
| | - Etienne Mangaud
- Laboratoire
Collisions Agrégats Réactivité, UMR 5589, IRSAMC, Université Toulouse III Paul Sabatier, F-31062 Toulouse, France
| | - Thiago Firmino
- Laboratoire
de Chimie Physique, CNRS, Université Paris-Sud, Université Paris Saclay, Orsay F-91405, France
| | - Aurélien de la Lande
- Laboratoire
de Chimie Physique, CNRS, Université Paris-Sud, Université Paris Saclay, Orsay F-91405, France
| | - Michèle Desouter-Lecomte
- Laboratoire
de Chimie Physique, CNRS, Université Paris-Sud, Université Paris Saclay, Orsay F-91405, France
| | - Hans-Dieter Meyer
- Theoretische
Chemie, Physikalisch-Chemisches Institut, Universität Heidelberg, INF 229, D-69120 Heidelberg, Germany
| | - Fabien Gatti
- Institut
des Sciences Moléculaires d’Orsay, UMR-CNRS 8214, Université Paris-Sud, Université Paris Saclay, Orsay F-91405, France
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42
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Hiscock HG, Mouritsen H, Manolopoulos DE, Hore PJ. Disruption of Magnetic Compass Orientation in Migratory Birds by Radiofrequency Electromagnetic Fields. Biophys J 2017; 113:1475-1484. [PMID: 28978441 DOI: 10.1016/j.bpj.2017.07.031] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 07/19/2017] [Accepted: 07/31/2017] [Indexed: 11/30/2022] Open
Abstract
The radical-pair mechanism has been put forward as the basis of the magnetic compass sense of migratory birds. Some of the strongest supporting evidence has come from behavioral experiments in which birds exposed to weak time-dependent magnetic fields lose their ability to orient in the geomagnetic field. However, conflicting results and skepticism about the requirement for abnormally long quantum coherence lifetimes have cast a shroud of uncertainty over these potentially pivotal studies. Using a recently developed computational approach, we explore the effects of various radiofrequency magnetic fields on biologically plausible radicals within the theoretical framework of radical-pair magnetoreception. We conclude that the current model of radical-pair magnetoreception is unable to explain the findings of the reported behavioral experiments. Assuming that an unknown mechanism amplifies the predicted effects, we suggest experimental conditions that have the potential to distinguish convincingly between the two distinct families of radical pairs currently postulated as magnetic compass sensors. We end by making recommendations for experimental protocols that we hope will increase the chance that future experiments can be independently replicated.
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Affiliation(s)
- Hamish G Hiscock
- Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory, Oxford, United Kingdom
| | - Henrik Mouritsen
- Institut für Biologie und Umweltwissenschaften, Carl von Ossietzky University of Oldenburg, Oldenburg, Germany; Research Centre for Neurosensory Sciences, Carl von Ossietzky University of Oldenburg, Oldenburg, Germany
| | - David E Manolopoulos
- Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory, Oxford, United Kingdom
| | - P J Hore
- Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory, Oxford, United Kingdom.
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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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44
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Review for chiral-at-metal complexes and metal-organic framework enantiomorphs. Sci Bull (Beijing) 2017; 62:1344-1354. [PMID: 36659297 DOI: 10.1016/j.scib.2017.09.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 08/13/2017] [Accepted: 09/08/2017] [Indexed: 01/21/2023]
Abstract
This review discusses chiral-at-metal complexes and introduces enantiomorphs from assembly structure. Owing to the diverse coordination number and activity of metal ions as chiral centers, abundant structures for chiral selectivity, catalysis, and polarized light-response are the notable advantages of the chiral-at-metal complexes. The rational design and preparation of linear multi-dentate ligands is a good choice to improve the stability of chiral complexes, such as multi-bonding structure for high stability as a self-limiting system. The bio-significance and potential application of chiral-at-metal complexes are discussed, such as the synergistic effect of catalysis and chiral selectivity of the metal center in enzymes. Enzyme could be remolded to replace the original central metal ions with highly active rare earth or precious metal ions to form artificial metalloenzyme or to remove the "redundant" part around the metal center to improve the accessibility of substrate. The polarized light-response mechanism of chiral opsin is introduced in relation to its role in animal migration. Metal-organic frameworks (MOFs) are crystalline and porous materials built from metal nodes or clusters and organic linkers and provide the possibility to prepare artificial enantiomorphs. The preparations, applications, and characterization methods of MOF enatiomorphs are therefore introduced. We hope this review inspires researchers at all levels of their career to consider the title topic in their own research in terms of its application and potential value.
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The sensitivity of a radical pair compass magnetoreceptor can be significantly amplified by radical scavengers. Sci Rep 2017; 7:11640. [PMID: 28912470 PMCID: PMC5599710 DOI: 10.1038/s41598-017-09914-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 07/31/2017] [Indexed: 11/08/2022] Open
Abstract
Birds have a remarkable ability to obtain navigational information from the Earth's magnetic field. The primary detection mechanism of this compass sense is uncertain but appears to involve the quantum spin dynamics of radical pairs formed transiently in cryptochrome proteins. We propose here a new version of the current model in which spin-selective recombination of the radical pair is not essential. One of the two radicals is imagined to react with a paramagnetic scavenger via spin-selective electron transfer. By means of simulations of the spin dynamics of cryptochrome-inspired radical pairs, we show that the new scheme offers two clear and important benefits. The sensitivity to a 50 μT magnetic field is greatly enhanced and, unlike the current model, the radicals can be more than 2 nm apart in the magnetoreceptor protein. The latter means that animal cryptochromes that have a tetrad (rather than a triad) of tryptophan electron donors can still be expected to be viable as magnetic compass sensors. Lifting the restriction on the rate of the spin-selective recombination reaction also means that the detrimental effects of inter-radical exchange and dipolar interactions can be minimised by placing the radicals much further apart than in the current model.
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46
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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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47
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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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48
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Heyers D, Elbers D, Bulte M, Bairlein F, Mouritsen H. The magnetic map sense and its use in fine-tuning the migration programme of birds. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2017; 203:491-497. [PMID: 28365788 DOI: 10.1007/s00359-017-1164-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 03/06/2017] [Accepted: 03/07/2017] [Indexed: 10/19/2022]
Abstract
The Earth's magnetic field is one of several natural cues, which migratory birds can use to derive directional ("compass") information for orientation on their biannual migratory journeys. Moreover, magnetic field effects on prominent aspects of the migratory programme of birds, such as migratory restlessness behaviour, fuel deposition and directional orientation, implicate that geomagnetic information can also be used to derive positional ("map") information. While the magnetic "compass" in migratory birds is likely to be based on radical pair-forming molecules embedded in their visual system, the sensory correlates underlying a magnetic "map" sense currently remain elusive. Behavioural, physiological and neurobiological findings indicate that the sensor is most likely innervated by the ophthalmic branch of the trigeminal nerve and based on magnetic iron particles. Information from this unknown sensor is neither necessary nor sufficient for a functional magnetic compass, but instead could contribute important components of a multifactorial "map" for global positioning. Positional information could allow migratory birds to make vitally important dynamic adaptations of their migratory programme at any relevant point during their journeys.
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Affiliation(s)
- D Heyers
- AG Animal Navigation, Faculty of Biology/Environmental Sciences, University of Oldenburg, 26111, Oldenburg, Germany. .,Research Centre for Neurosensory Sciences, University of Oldenburg, 26111, Oldenburg, Germany.
| | - D Elbers
- AG Animal Navigation, Faculty of Biology/Environmental Sciences, University of Oldenburg, 26111, Oldenburg, Germany.,Research Centre for Neurosensory Sciences, University of Oldenburg, 26111, Oldenburg, Germany.,AG Biochemistry, Faculty of Medicine/Health Sciences, University of Oldenburg, 26111, Oldenburg, Germany
| | - M Bulte
- , Schmidtkunzstraße 13, 86199, Augsburg, Germany.,Institute for Avian Research "Vogelwarte Helgoland", 26386, Wilhelmshaven, Germany
| | - F Bairlein
- Institute for Avian Research "Vogelwarte Helgoland", 26386, Wilhelmshaven, Germany
| | - H Mouritsen
- AG Animal Navigation, Faculty of Biology/Environmental Sciences, University of Oldenburg, 26111, Oldenburg, Germany.,Research Centre for Neurosensory Sciences, University of Oldenburg, 26111, Oldenburg, Germany
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49
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Magnetic activation in the brain of the migratory northern wheatear (Oenanthe oenanthe). J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2017; 203:591-600. [DOI: 10.1007/s00359-017-1167-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 03/16/2017] [Accepted: 03/19/2017] [Indexed: 10/19/2022]
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50
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Kavokin K. Can a hybrid chemical-ferromagnetic model of the avian compass explain its outstanding sensitivity to magnetic noise? PLoS One 2017; 12:e0173887. [PMID: 28296939 PMCID: PMC5352016 DOI: 10.1371/journal.pone.0173887] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Accepted: 02/28/2017] [Indexed: 11/30/2022] Open
Abstract
While many properties of the magnetic compass of migratory birds are satisfactory explained within the chemical model of magnetoreception, its extreme sensitivity to radio-frequency magnetic fields remains a mystery. Apparently, this difficulty could be overcome if the magnetoreceptor model were augmented with a magnetite nanoparticle, which would amplify the magnetic field at the position of the magneto-sensitive cryptochrome molecule. However, comparison of the radio-frequency power used in the experiment with intrinsic magnetization noise of such a particle, estimated from the theory of fluctuations, shows that the required sensitivity cannot be reached with realistic parameters of iron-oxide nanocrystals.
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Affiliation(s)
- Kirill Kavokin
- Spin Optics Laboratory, St. Petersburg State University, St. Petersburg, Russia
- I.M.Sechenov Institute of Evolutionary Physiology and Biochemistry RAS, St. Petersburg, Russia
- * E-mail:
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