1
|
Frederiksen A, Aldag M, Solov’yov IA, Gerhards L. Activation of Cryptochrome 4 from Atlantic Herring. Biology (Basel) 2024; 13:262. [PMID: 38666874 PMCID: PMC11048568 DOI: 10.3390/biology13040262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 04/04/2024] [Accepted: 04/11/2024] [Indexed: 04/28/2024]
Abstract
Marine fish migrate long distances up to hundreds or even thousands of kilometers for various reasons that include seasonal dependencies, feeding, or reproduction. The ability to perceive the geomagnetic field, called magnetoreception, is one of the many mechanisms allowing some fish to navigate reliably in the aquatic realm. While it is believed that the photoreceptor protein cryptochrome 4 (Cry4) is the key component for the radical pair-based magnetoreception mechanism in night migratory songbirds, the Cry4 mechanism in fish is still largely unexplored. The present study aims to investigate properties of the fish Cry4 protein in order to understand the potential involvement in a radical pair-based magnetoreception. Specifically, a computationally reconstructed atomistic model of Cry4 from the Atlantic herring (Clupea harengus) was studied employing classical molecular dynamics (MD) and quantum mechanics/molecular mechanics (QM/MM) methods to investigate internal electron transfers and the radical pair formation. The QM/MM simulations reveal that electron transfers occur similarly to those found experimentally and computationally in Cry4 from European robin (Erithacus rubecula). It is therefore plausible that the investigated Atlantic herring Cry4 has the physical and chemical properties to form radical pairs that in turn could provide fish with a radical pair-based magnetic field compass sensor.
Collapse
Affiliation(s)
- Anders Frederiksen
- Institute of Physics, Carl von Ossietzky University of Oldenburg, Carl-von-Ossietzky Straße 9-11, 26129 Oldenburg, Germany; (A.F.); (M.A.); (I.A.S.)
| | - Mandus Aldag
- Institute of Physics, Carl von Ossietzky University of Oldenburg, Carl-von-Ossietzky Straße 9-11, 26129 Oldenburg, Germany; (A.F.); (M.A.); (I.A.S.)
| | - Ilia A. Solov’yov
- Institute of Physics, Carl von Ossietzky University of Oldenburg, Carl-von-Ossietzky Straße 9-11, 26129 Oldenburg, Germany; (A.F.); (M.A.); (I.A.S.)
- Research Centre for Neurosensory Sciences, Carl von Ossietzky University of Oldenburg, Carl-von-Ossietzky Straße 9-11, 26129 Oldenburg, Germany
- Center for Nanoscale Dynamics (CENAD), Carl von Ossietzky University of Oldenburg, Ammerländer Heerstr. 114-118, 26129 Oldenburg, Germany
| | - Luca Gerhards
- Institute of Physics, Carl von Ossietzky University of Oldenburg, Carl-von-Ossietzky Straße 9-11, 26129 Oldenburg, Germany; (A.F.); (M.A.); (I.A.S.)
| |
Collapse
|
2
|
Bradlaugh AA, Fedele G, Munro AL, Hansen CN, Hares JM, Patel S, Kyriacou CP, Jones AR, Rosato E, Baines RA. Essential elements of radical pair magnetosensitivity in Drosophila. Nature 2023; 615:111-116. [PMID: 36813962 PMCID: PMC9977682 DOI: 10.1038/s41586-023-05735-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 01/16/2023] [Indexed: 02/24/2023]
Abstract
Many animals use Earth's magnetic field (also known as the geomagnetic field) for navigation1. The favoured mechanism for magnetosensitivity involves a blue-light-activated electron-transfer reaction between flavin adenine dinucleotide (FAD) and a chain of tryptophan residues within the photoreceptor protein CRYPTOCHROME (CRY). The spin-state of the resultant radical pair, and therefore the concentration of CRY in its active state, is influenced by the geomagnetic field2. However, the canonical CRY-centric radical-pair mechanism does not explain many physiological and behavioural observations2-8. Here, using electrophysiology and behavioural analyses, we assay magnetic-field responses at the single-neuron and organismal levels. We show that the 52 C-terminal amino acid residues of Drosophila melanogaster CRY, lacking the canonical FAD-binding domain and tryptophan chain, are sufficient to facilitate magnetoreception. We also show that increasing intracellular FAD potentiates both blue-light-induced and magnetic-field-dependent effects on the activity mediated by the C terminus. High levels of FAD alone are sufficient to cause blue-light neuronal sensitivity and, notably, the potentiation of this response in the co-presence of a magnetic field. These results reveal the essential components of a primary magnetoreceptor in flies, providing strong evidence that non-canonical (that is, non-CRY-dependent) radical pairs can elicit magnetic-field responses in cells.
Collapse
Affiliation(s)
- Adam A Bradlaugh
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Giorgio Fedele
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
- Department of Biology, Ecology and Earth Sciences (DiBEST), University of Calabria, Rende, Italy
| | - Anna L Munro
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Celia Napier Hansen
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
| | - John M Hares
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
- Pelican Healthcare, Cardiff, UK
| | - Sanjai Patel
- Manchester Fly Facility, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | | | - Alex R Jones
- Biometrology, Chemical and Biological Sciences Department, National Physical Laboratory, Teddington, UK
| | - Ezio Rosato
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK.
| | - Richard A Baines
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK.
| |
Collapse
|
3
|
Ledray AP, Dwaraknath S, Chakarawet K, Sponholtz MR, Merchen C, Van Stappen C, Rao G, Britt RD, Lu Y. Tryptophan Can Promote Oxygen Reduction to Water in a Biosynthetic Model of Heme Copper Oxidases. Biochemistry 2023; 62:388-395. [PMID: 36215733 DOI: 10.1021/acs.biochem.2c00300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Heme-copper oxidases (HCOs) utilize tyrosine (Tyr) to donate one of the four electrons required for the reduction of O2 to water in biological respiration, while tryptophan (Trp) is speculated to fulfill the same role in cyt bd oxidases. We previously engineered myoglobin into a biosynthetic model of HCOs and demonstrated the critical role that Tyr serves in the oxygen reduction reaction (ORR). To address the roles of Tyr and Trp in these oxidases, we herein report the preparation of the same biosynthetic model with the Tyr replaced by Trp and further demonstrate that Trp can also promote the ORR, albeit with lower activity. An X-ray crystal structure of the Trp variant shows a hydrogen-bonding network involving two water molecules that are organized by Trp, similar to that in the Tyr variant, which is absent in the crystal structure with the native Phe residue. Additional electron paramagnetic resonance measurements are consistent with the formation of a Trp radical species upon reacting with H2O2. We attribute the lower activity of the Trp variant to Trp's higher reduction potential relative to Tyr. Together, these findings demonstrate, for the first time, that Trp can indeed promote the ORR and provides a structural basis for the observation of varying activities. The results support a redox role for the conserved Trp in bd oxidase while suggesting that HCOs use Tyr instead of Trp to achieve higher reactivity.
Collapse
Affiliation(s)
- Aaron P Ledray
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Sudharsan Dwaraknath
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Khetpakorn Chakarawet
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Madeline R Sponholtz
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Claire Merchen
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Casey Van Stappen
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Guodong Rao
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - R David Britt
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Yi Lu
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States.,Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.,Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| |
Collapse
|
4
|
An ML, Miao JL. Genetic and Molecular Characterization of a Dash Cryptochrome Homologous Gene from Antarctic Diatom Phaeodactylum tricornutum ICE-H. Mol Biol 2022. [DOI: 10.1134/s0026893322060024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
5
|
Alachkar A. Aromatic patterns: Tryptophan aromaticity as a catalyst for the emergence of life and rise of consciousness. Phys Life Rev 2022; 42:93-114. [PMID: 35905538 DOI: 10.1016/j.plrev.2022.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 07/12/2022] [Indexed: 11/28/2022]
Abstract
Sunlight held the key to the origin of life on Earth. The earliest life forms, cyanobacteria, captured the sunlight to generate energy through photosynthesis. Life on Earth evolved in accordance with the circadian rhythms tied to sensitivity to sunlight patterns. A unique feature of cyanobacterial photosynthetic proteins and circadian rhythms' molecules, and later of nearly all photon-sensing molecules throughout evolution, is that the aromatic amino acid tryptophan (Trp) resides at the center of light-harvesting active sites. In this perspective, I review the literature and integrate evidence from different scientific fields to explore the role Trp plays in photon-sensing capabilities of living organisms through its resonance delocalization of π-electrons. The observations presented here are the product of apparently unrelated phenomena throughout evolution, but nevertheless share consistent patterns of photon-sensing by Trp-containing and Trp-derived molecules. I posit the unique capacity to transfer electrons during photosynthesis in the earliest life forms is conferred to Trp due to its aromaticity. I propose this ability evolved to assume more complex functions, serving as a host for mechanisms underlying mental aptitudes - a concept which provides a theoretical basis for defining the neural correlates of consciousness. The argument made here is that Trp aromaticity may have allowed for the inception of the mechanistic building blocks used to fabricate complexity in higher forms of life. More specifically, Trp aromatic non-locality may have acted as a catalyst for the emergence of consciousness by instigating long-range synchronization and stabilizing the large-scale coherence of neural networks, which mediate functional brain activity. The concepts proposed in this perspective provide a conceptual foundation that invites further interdisciplinary dialogue aimed at examining and defining the role of aromaticity (beyond Trp) in the emergence of life and consciousness.
Collapse
Affiliation(s)
- Amal Alachkar
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, University of California, Irvine, CA 92697, USA; UC Irvine Center for the Neurobiology of Learning and Memory, University of California-Irvine, Irvine, CA 92697, USA; Institute for Genomics and Bioinformatics, School of Information and Computer Sciences, University of California, Irvine, CA 92697, USA.
| |
Collapse
|
6
|
Lacombat F, Espagne A, Dozova N, Plaza P, Müller P, Emmerich HJ, Saft M, Essen LO. Ultrafast photoreduction dynamics of a new class of CPD photolyases. Photochem Photobiol Sci 2021; 20:733-746. [PMID: 33977513 DOI: 10.1007/s43630-021-00048-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 04/22/2021] [Indexed: 01/09/2023]
Abstract
NewPHL is a recently discovered subgroup of ancestral DNA photolyases. Its domain architecture displays pronounced differences from that of canonical photolyases, in particular at the level of the characteristic electron transfer chain, which is limited to merely two tryptophans, instead of the "classical" three or four. Using transient absorption spectroscopy, we show that the dynamics of photoreduction of the oxidized FAD cofactor in the NewPHL begins similarly as that in canonical photolyases, i.e., with a sub-ps primary reduction of the excited FAD cofactor by an adjacent tryptophan, followed by migration of the electron hole towards the second tryptophan in the tens of ps regime. However, the resulting tryptophanyl radical then undergoes an unprecedentedly fast deprotonation in less than 100 ps in the NewPHL. In spite of the stabilization effect of this deprotonation, almost complete charge recombination follows in two phases of ~ 950 ps and ~ 50 ns. Such a rapid recombination of the radical pair implies that the first FAD photoreduction step, i.e., conversion of the fully oxidized to the semi-quinone state, should be rather difficult in vivo. We hence suggest that the flavin chromophore likely switches only between its semi-reduced and fully reduced form in NewPHL under physiological conditions.
Collapse
Affiliation(s)
- Fabien Lacombat
- PASTEUR, Département de Chimie, École Normale Supérieure, PSL University, CNRS, Sorbonne Université, 75005, Paris, France
| | - Agathe Espagne
- PASTEUR, Département de Chimie, École Normale Supérieure, PSL University, CNRS, Sorbonne Université, 75005, Paris, France
| | - Nadia Dozova
- PASTEUR, Département de Chimie, École Normale Supérieure, PSL University, CNRS, Sorbonne Université, 75005, Paris, France
| | - Pascal Plaza
- PASTEUR, Département de Chimie, École Normale Supérieure, PSL University, CNRS, Sorbonne Université, 75005, Paris, France.
| | - Pavel Müller
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198, Gif-sur-Yvette, France.
| | - Hans-Joachim Emmerich
- Department of Chemistry, Center for Synthetic Microbiology, Philipps University, 35032, Marburg, Germany
| | - Martin Saft
- Department of Chemistry, Center for Synthetic Microbiology, Philipps University, 35032, Marburg, Germany
| | - Lars-Oliver Essen
- Department of Chemistry, Center for Synthetic Microbiology, Philipps University, 35032, Marburg, Germany.
| |
Collapse
|
7
|
Emmerich HJ, Saft M, Schneider L, Kock D, Batschauer A, Essen LO. A topologically distinct class of photolyases specific for UV lesions within single-stranded DNA. Nucleic Acids Res 2021; 48:12845-12857. [PMID: 33270891 PMCID: PMC7736829 DOI: 10.1093/nar/gkaa1147] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 11/07/2020] [Accepted: 11/09/2020] [Indexed: 11/30/2022] Open
Abstract
Photolyases are ubiquitously occurring flavoproteins for catalyzing photo repair of UV-induced DNA damages. All photolyases described so far have a bilobal architecture with a C-terminal domain comprising flavin adenine dinucleotide (FAD) as catalytic cofactor and an N-terminal domain capable of harboring an additional antenna chromophore. Using sequence-similarity network analysis we discovered a novel subgroup of the photolyase/cryptochrome superfamily (PCSf), the NewPHLs. NewPHL occur in bacteria and have an inverted topology with an N-terminal catalytic domain and a C-terminal domain for sealing the FAD binding site from solvent access. By characterizing two NewPHL we show a photochemistry characteristic of other PCSf members as well as light-dependent repair of CPD lesions. Given their common specificity towards single-stranded DNA many bacterial species use NewPHL as a substitute for DASH-type photolyases. Given their simplified architecture and function we suggest that NewPHL are close to the evolutionary origin of the PCSf.
Collapse
Affiliation(s)
- Hans-Joachim Emmerich
- Unit for Structural Biochemistry, Department of Chemistry, Philipps University Marburg, Hans-Meerwein Straße 4, 35032 Marburg, Germany
| | - Martin Saft
- Unit for Structural Biochemistry, Department of Chemistry, Philipps University Marburg, Hans-Meerwein Straße 4, 35032 Marburg, Germany
| | - Leonie Schneider
- Unit for Structural Biochemistry, Department of Chemistry, Philipps University Marburg, Hans-Meerwein Straße 4, 35032 Marburg, Germany
| | - Dennis Kock
- Department of Biology, Philipps University Marburg, Karl-von-Frisch-Straße 8, 35032 Marburg, Germany
| | - Alfred Batschauer
- Department of Biology, Philipps University Marburg, Karl-von-Frisch-Straße 8, 35032 Marburg, Germany
| | - Lars-Oliver Essen
- Unit for Structural Biochemistry, Department of Chemistry, Philipps University Marburg, Hans-Meerwein Straße 4, 35032 Marburg, Germany.,Center of Synthetic Microbiology, Philipps University Marburg, Hans-Meerwein Straße 4, 35032 Marburg, Germany
| |
Collapse
|
8
|
Richter M, Fingerhut BP. Regulatory Impact of the C-Terminal Tail on Charge Transfer Pathways in Drosophila Cryptochrome. Molecules 2020; 25:E4810. [PMID: 33086760 DOI: 10.3390/molecules25204810] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 10/14/2020] [Accepted: 10/14/2020] [Indexed: 01/02/2023] Open
Abstract
Interconnected transcriptional and translational feedback loops are at the core of the molecular mechanism of the circadian clock. Such feedback loops are synchronized to external light entrainment by the blue light photoreceptor cryptochrome (CRY) that undergoes conformational changes upon light absorption by an unknown photoexcitation mechanism. Light-induced charge transfer (CT) reactions in Drosophila CRY (dCRY) are investigated by state-of-the-art simulations that reveal a complex, multi-redox site nature of CT dynamics on the microscopic level. The simulations consider redox-active chromophores of the tryptophan triad (Trp triad) and further account for pathways mediated by W314 and W422 residues proximate to the C-terminal tail (CTT), thus avoiding a pre-bias to specific W-mediated CT pathways. The conducted dissipative quantum dynamics simulations employ microscopically derived model Hamiltonians and display complex and ultrafast CT dynamics on the picosecond timescale, subtly balanced by the electrostatic environment of dCRY. In silicio point mutations provide a microscopic basis for rationalizing particular CT directionality and demonstrate the degree of electrostatic control realized by a discrete set of charged amino acid residues. The predicted participation of CT states in proximity to the CTT relates the directionality of CT reactions to the spatial vicinity of a linear interaction motif. The results stress the importance of CTT directional charge transfer in addition to charge transfer via the Trp triad and call for the use of full-length CRY models including the interactions of photolyase homology region (PHR) and CTT domains.
Collapse
|
9
|
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
| |
Collapse
|
10
|
Holub D, Lamparter T, Elstner M, Gillet N. Biological relevance of charge transfer branching pathways in photolyases. Phys Chem Chem Phys 2019; 21:17072-17081. [PMID: 31313765 DOI: 10.1039/c9cp01609k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The repair of sun-induced DNA lesions by photolyases is driven by a photoinduced electron transfer from a fully reduced FAD to the damaged DNA. A chain of several aromatic residues connecting FAD to solvent ensures the prior photoreduction of the FAD cofactor. In PhrA, a class III CPD photolyase, two branching tryptophan charge transfer pathways have been characterized. According to previous experiments, both pathways play a role in the FAD photoreduction. To provide a molecular insight to the charge transfer abilities of both pathways, we perform multiscales simulations where the protein motion and the positive charge are simultaneously propagated. Our computational approach reveals that one pathway drives a very fast charge transfer whereas the other pathway provides a very good thermodynamic stabilization of the positive charge. During the simulations, the positive charge firstly moves on the fast triad, while a reorganization of the close FAD˙- environment occurs. Then, backward transfers can lead to the propagation of the positive charge on the second pathway. After one nanosecond, we observe a nearly equal probability to find the charge at ending tryptophan of either pathway; eventually the charge distribution will likely evolve towards a charge stabilization on the last tryptophan of the slowest pathway. Our results highlight the role the protein environment, which manages the association of a kinetic and a thermodynamic pathways to trigger a fast and efficient FAD photoreduction.
Collapse
Affiliation(s)
- Daniel Holub
- Department for Theoretical Chemical Biology, Institute for Physical Chemistry, Karlsruhe Institute for Technology, Kaiserstr. 12, 76131, Karlsruhe, Germany.
| | - Tilman Lamparter
- Botanical Institute, Karlsruhe Institute of Technology, Fritz Haber Weg 4, 76131, Karlsruhe, Germany
| | - Marcus Elstner
- Department for Theoretical Chemical Biology, Institute for Physical Chemistry, Karlsruhe Institute for Technology, Kaiserstr. 12, 76131, Karlsruhe, Germany. and Institute of Biological Interfaces (IBG2), Karlsruhe Institute for Technology, Kaiserstr. 12, 76131, Karlsruhe, Germany
| | - Natacha Gillet
- Department for Theoretical Chemical Biology, Institute for Physical Chemistry, Karlsruhe Institute for Technology, Kaiserstr. 12, 76131, Karlsruhe, Germany.
| |
Collapse
|
11
|
Bialas C, Barnard DT, Auman DB, McBride RA, Jarocha LE, Hore PJ, Dutton PL, Stanley RJ, Moser CC. Ultrafast flavin/tryptophan radical pair kinetics in a magnetically sensitive artificial protein. Phys Chem Chem Phys 2019; 21:13453-13461. [PMID: 31187821 DOI: 10.1039/c9cp01916b] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Radical pair formation and decay are implicated in a wide range of biological processes including avian magnetoreception. However, studying such biological radical pairs is complicated by both the complexity and relative fragility of natural systems. To resolve open questions about how natural flavin-amino acid radical pair systems are engineered, and to create new systems with novel properties, we developed a stable and highly adaptable de novo artificial protein system. These protein maquettes are designed with intentional simplicity and transparency to tolerate aggressive manipulations that are impractical or impossible in natural proteins. Here we characterize the ultrafast dynamics of a series of maquettes with differing electron-transfer distance between a covalently ligated flavin and a tryptophan in an environment free of other potential radical centers. We resolve the spectral signatures of the cysteine-ligated flavin singlet and triplet states and reveal the picosecond formation and recombination of singlet-born radical pairs. Magnetic field-sensitive triplet-born radical pair formation and recombination occurs at longer timescales. These results suggest that both triplet- and singlet-born radical pairs could be exploited as biological magnetic sensors.
Collapse
Affiliation(s)
- Chris Bialas
- Johnson Research Foundation, Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Sjulstok E, Lüdemann G, Kubař T, Elstner M, Solov'yov IA. Molecular Insights into Variable Electron Transfer in Amphibian Cryptochrome. Biophys J 2019; 114:2563-2572. [PMID: 29874607 DOI: 10.1016/j.bpj.2018.04.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 04/04/2018] [Accepted: 04/05/2018] [Indexed: 01/23/2023] Open
Abstract
Cryptochrome proteins are activated by the absorption of blue light, leading to the formation of radical pairs through electron transfer in the active site. Recent experimental studies have shown that once some of the amino acid residues in the active site of Xenopus laevis cryptochrome DASH are mutated, radical-pair formation is still observed. In this study, we computationally investigate electron-transfer pathways in the X. laevis cryptochrome DASH by extensively equilibrating a previously established homology model using molecular dynamics simulations and then mutating key amino acids involved in the electron transfer. The electron-transfer pathways are then probed by using tight-binding density-functional theory. We report the alternative electron-transfer pathways resolved at the molecular level and, through comparison of amino acid sequences for cryptochromes from different species, we demonstrate that one of these alternative electron-transfer pathways could be general for all cryptochrome DASH proteins.
Collapse
Affiliation(s)
- Emil Sjulstok
- Department of Physics, Chemistry, and Pharmacy, University of Southern Denmark, Odense, Denmark
| | - Gesa Lüdemann
- Institute of Physical Chemistry, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Tomáš Kubař
- Institute of Physical Chemistry, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Marcus Elstner
- Institute of Physical Chemistry, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Ilia A Solov'yov
- Department of Physics, Chemistry, and Pharmacy, University of Southern Denmark, Odense, Denmark.
| |
Collapse
|
13
|
Abstract
Flavin semiquinone redox states are important intermediates in a broad variety of reactions catalyzed by flavoproteins. As paramagnetic states they can be favorably probed by EPR spectroscopy in all its flavors. This review summarizes recent results in the characterization of flavin radicals. On the one hand, flavin radical states, e.g., trapped as reaction intermediates, can be characterized using modern pulsed EPR methods to unravel their electronic structure and to gain information about the surrounding environment and its changes on protein action. On the other hand, short-lived intermediate flavin radical states generated, e.g., photochemically, can be followed by time-resolved EPR, which allows a direct tracking of flavin-dependent reactions with a temporal resolution reaching nanoseconds.
Collapse
Affiliation(s)
- Daniel Nohr
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Stefan Weber
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Erik Schleicher
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany.
| |
Collapse
|
14
|
|
15
|
Kutta RJ, Archipowa N, Scrutton NS. The sacrificial inactivation of the blue-light photosensor cryptochrome from Drosophila melanogaster. Phys Chem Chem Phys 2018; 20:28767-28776. [PMID: 30417904 PMCID: PMC6250122 DOI: 10.1039/c8cp04671a] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 09/25/2018] [Indexed: 01/10/2023]
Abstract
Drosophila melanogaster cryptochrome functions as the primary blue-light receptor that mediates circadian photo entrainment. Absorption of a photon leads to reduction of the protein-bound FAD via consecutive electron transfer along a conserved tryptophan tetrad resembling the signalling state required for conformational changes and induction of subsequent signalling cascades. However, how the initial photochemistry and subsequent dark processes leading to downstream signalling are linked to each other at the molecular level is still poorly understood. Here, we investigated in detail the initial photochemical events in DmCRY by time-resolved and stationary absorption spectroscopy combined with quantum chemical and molecular dynamics calculations. We resolved the early events along the conserved tryptophan tetrad and the final deprotonation of the terminal tryptophanyl radical cation. These initial events lead to conformational changes, such as the known C-terminal tail release, Trp decomposition, and finally FAD release providing evidence that DmCRY does not undergo a photocycle. We propose that light is a negative regulator of DmCRY stability even under in vitro conditions where the proteasomal machinery is missing, that is in line with its biological function, i.e. entrainment of the circadian clock.
Collapse
Affiliation(s)
- Roger Jan Kutta
- Manchester Institute of Biotechnology (MIB) and School of Chemistry
, The University of Manchester
,
131 Princess Street
, Manchester
, M1 7DN
, UK
.
| | - Nataliya Archipowa
- Manchester Institute of Biotechnology (MIB) and School of Chemistry
, The University of Manchester
,
131 Princess Street
, Manchester
, M1 7DN
, UK
.
| | - Nigel Shaun Scrutton
- Manchester Institute of Biotechnology (MIB) and School of Chemistry
, The University of Manchester
,
131 Princess Street
, Manchester
, M1 7DN
, UK
.
| |
Collapse
|
16
|
Worster SB, Hore PJ. Proposal to use superparamagnetic nanoparticles to test the role of cryptochrome in magnetoreception. J R Soc Interface 2018; 15:20180587. [PMID: 30381345 PMCID: PMC6228473 DOI: 10.1098/rsif.2018.0587] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 10/08/2018] [Indexed: 11/12/2022] Open
Abstract
Evidence is accumulating to support the hypothesis that some animals use light-induced radical pairs to detect the direction of the Earth's magnetic field. Cryptochrome proteins seem to be involved in the sensory pathway but it is not yet clear if they are the magnetic sensors: they could, instead, play a non-magnetic role as signal transducers downstream of the primary sensor. Here we propose an experiment with the potential to distinguish these functions. The principle is to use superparamagnetic nanoparticles to disable any magnetic sensing role by enhancing the electron spin relaxation of the radicals so as to destroy their spin correlation. We use spin dynamics simulations to show that magnetoferritin, a synthetic, protein-based nanoparticle, has the required properties. If cryptochrome is the primary sensor, then it should be inactivated by a magnetoferritin particle placed 12-16 nm away. This would prevent a bird from using its magnetic compass in behavioural tests and abolish magnetically sensitive neuronal firing in the retina. The key advantage of such an experiment is that any signal transduction role should be completely unaffected by the tiny magnetic interactions (≪kBT) required to enhance the spin relaxation of the radical pair.
Collapse
Affiliation(s)
- Susannah Bourne Worster
- Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford OX1 3QZ, UK
| | - P J Hore
- Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford OX1 3QZ, UK
| |
Collapse
|
17
|
Abstract
The magnetic compass sense utilized by migratory birds for long-distance navigation functions only once light of a certain wavelength is present. This piece of evidence fits partially with the popular hypothesis of chemical magnetoreception in cryptochrome proteins, located in the bird retina. According to this hypothesis a magnetosensitive radical pair is produced after photoexcitation of an FAD cofactor inside cryptochrome, and as such the absorption properties of FAD are of crucial importance for cryptochrome activation. However, we reveal that absorption spectra of FAD show very little variation between six different cryptochromes, suggesting that the electronic transitions are barely affected by the chemical differences in the proteins. This conclusion hints on the presence of a secondary photoreceptor or cofactor that could be necessary to explain green-light-activated magnetoreception in birds.
Collapse
Affiliation(s)
- Claus Nielsen
- Department of Physics, Chemistry and Pharmacy , University of Southern Denmark , DK-5230 Odense M , Denmark
| | - Morten S Nørby
- Department of Physics, Chemistry and Pharmacy , University of Southern Denmark , DK-5230 Odense M , Denmark
| | - Jacob Kongsted
- Department of Physics, Chemistry and Pharmacy , University of Southern Denmark , DK-5230 Odense M , Denmark
| | - Ilia A Solov'yov
- Department of Physics, Chemistry and Pharmacy , University of Southern Denmark , DK-5230 Odense M , Denmark
| |
Collapse
|
18
|
Lin C, Top D, Manahan CC, Young MW, Crane BR. Circadian clock activity of cryptochrome relies on tryptophan-mediated photoreduction. Proc Natl Acad Sci U S A 2018; 115:3822-7. [PMID: 29581265 DOI: 10.1073/pnas.1719376115] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Cryptochromes (CRYs) entrain the circadian clocks of plants and animals to light. Irradiation of the Drosophila cryptochrome (dCRY) causes reduction of an oxidized flavin cofactor by a chain of conserved tryptophan (Trp) residues. However, it is unclear how redox chemistry within the Trp chain couples to dCRY-mediated signaling. Here, we show that substitutions of four key Trp residues to redox-active tyrosine and redox-inactive phenylalanine tune the light sensitivity of dCRY photoreduction, conformational activation, cellular stability, and targeted degradation of the clock protein timeless (TIM). An essential surface Trp gates electron flow into the flavin cofactor, but can be relocated for enhanced photoactivation. Differential effects of Trp-mediated flavin photoreduction on cellular turnover of TIM and dCRY indicate that these activities are separated in time and space. Overall, the dCRY Trp chain has evolutionary importance for light sensing, and its manipulation has implications for optogenetic applications of CRYs.
Collapse
|
19
|
Holub D, Ma H, Krauß N, Lamparter T, Elstner M, Gillet N. Functional role of an unusual tyrosine residue in the electron transfer chain of a prokaryotic (6-4) photolyase. Chem Sci 2017; 9:1259-1272. [PMID: 29675172 PMCID: PMC5887102 DOI: 10.1039/c7sc03386a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 12/09/2017] [Indexed: 11/21/2022] Open
Abstract
Cryptochromes and photolyases form a flavoprotein family in which the FAD chromophore undergoes light induced changes of its redox state. During this process, termed photoreduction, electrons flow from the surface via conserved amino acid residues to FAD. The bacterial (6-4) photolyase PhrB belongs to a phylogenetically ancient group. Photoreduction of PhrB differs from the typical pattern because the amino acid of the electron cascade next to FAD is a tyrosine (Tyr391), whereas photolyases and cryptochromes of other groups have a tryptophan as direct electron donor of FAD. Mutagenesis studies have identified Trp342 and Trp390 as essential for charge transfer. Trp342 is located at the periphery of PhrB while Trp390 connects Trp342 and Tyr391. The role of Tyr391, which lies between Trp390 and FAD, is however unclear as its replacement by phenylalanine did not block photoreduction. Experiments reported here, which replace Tyr391 by Ala, show that photoreduction is blocked, underlining the relevance of Tyr/Phe at position 391 and indicating that charge transfer occurs via the triad 391-390-342. This raises the question, why PhrB positions a tyrosine at this location, having a less favourable ionisation potential than tryptophan, which occurs at this position in many proteins of the photolyase/cryptochrome family. Tunnelling matrix calculations show that tyrosine or phenylalanine can be involved in a productive bridged electron transfer between FAD and Trp390, in line with experimental findings. Since replacement of Tyr391 by Trp resulted in loss of FAD and DMRL chromophores, electron transfer cannot be studied experimentally in this mutant, but calculations on a mutant model suggest that Trp might participate in the electron transfer cascade. Charge transfer simulations reveal an unusual stabilization of the positive charge on site 391 compared to other photolyases or cryptochromes. Water molecules near Tyr391 offer a polar environment which stabilizes the positive charge on this site, thereby lowering the energetic barrier intrinsic to tyrosine. This opens a second charge transfer channel in addition to tunnelling through the tyrosine barrier, based on hopping and therefore transient oxidation of Tyr391, which enables a fast charge transfer similar to proteins utilizing a tryptophan-triad. Our results suggest that evolution of the first site of the redox chain has just been possible by tuning the protein structure and environment to manage a downhill hole transfer process from FAD to solvent.
Collapse
Affiliation(s)
- Daniel Holub
- Department for Theoretical Chemical Biology , Institute for Physical Chemistry , Karlsruhe Institute for Technology , Kaiserstr. 12 , 76131 , Karlsruhe , Germany .
| | - Hongju Ma
- Botanical Institute , Karlsruhe Institute for Technology , Fritz Haber Weg 4 , 76131 , Karlsruhe , Germany
| | - Norbert Krauß
- Botanical Institute , Karlsruhe Institute for Technology , Fritz Haber Weg 4 , 76131 , Karlsruhe , Germany
| | - Tilman Lamparter
- Botanical Institute , Karlsruhe Institute for Technology , Fritz Haber Weg 4 , 76131 , Karlsruhe , Germany
| | - Marcus Elstner
- Department for Theoretical Chemical Biology , Institute for Physical Chemistry , Karlsruhe Institute for Technology , Kaiserstr. 12 , 76131 , Karlsruhe , Germany . .,Institute of Biological Interfaces (IGB2) , Karlsruhe Institute for Technology , Kaiserstr. 12 , 76131 , Karlsruhe , Germany
| | - Natacha Gillet
- Department for Theoretical Chemical Biology , Institute for Physical Chemistry , Karlsruhe Institute for Technology , Kaiserstr. 12 , 76131 , Karlsruhe , Germany .
| |
Collapse
|
20
|
Friis I, Sjulstok E, Solov'yov IA. Computational reconstruction reveals a candidate magnetic biocompass to be likely irrelevant for magnetoreception. Sci Rep 2017; 7:13908. [PMID: 29066765 PMCID: PMC5654753 DOI: 10.1038/s41598-017-13258-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 09/20/2017] [Indexed: 11/30/2022] Open
Abstract
Birds use the magnetic field of the Earth to navigate during their annual migratory travel. The possible mechanism to explain the biophysics of this compass sense involves electron transfers within the photoreceptive protein cryptochrome. The magnetoreceptive functioning of cryptochromes is supposedly facilitated through an iron rich polymer complex which couples to multiple cryptochromes. The present investigation aims to independently reconstruct this complex and describe its interaction with Drosophila melanogaster cryptochromes. The polymer complex consists of ISCA1 protein monomers with internally bound iron sulphur clusters and simultaneously binds ten cryptochromes. Through molecular dynamics we have analysed the stability of the ISCA1-cryptochrome complex and characterized the interaction at the binding sites between individual cryptochrome and ISCA1. It is found that the cryptochrome binding to the ISCA1 polymer is not uniform and that the binding affinity depends on its placement along the ISCA1 polymer. This finding supports the claim that the individual ISCA1 monomer acts as possible intracellular interaction partner of cryptochrome, but the proposed existence of an elongated ISCA1 polymer with multiple attached cryptochromes appears to be questionable.
Collapse
Affiliation(s)
- Ida Friis
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK-5230, Odense M, Denmark.
| | - Emil Sjulstok
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK-5230, Odense M, Denmark
| | - Ilia A Solov'yov
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK-5230, Odense M, Denmark.
| |
Collapse
|
21
|
Yamamoto J, Shimizu K, Kanda T, Hosokawa Y, Iwai S, Plaza P, Müller P. Loss of Fourth Electron-Transferring Tryptophan in Animal (6–4) Photolyase Impairs DNA Repair Activity in Bacterial Cells. Biochemistry 2017; 56:5356-5364. [DOI: 10.1021/acs.biochem.7b00366] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Junpei Yamamoto
- Graduate
School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan
| | - Kohei Shimizu
- Graduate
School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan
| | - Takahiro Kanda
- Graduate
School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan
| | - Yuhei Hosokawa
- Graduate
School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan
| | - Shigenori Iwai
- Graduate
School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan
| | - Pascal Plaza
- PASTEUR,
Département de chimie, École normale supérieure, UPMC Univ. Paris 06, CNRS, PSL Research University, 75005 Paris, France
- Sorbonne Universités, UPMC Univ. Paris 06, École normale supérieure, CNRS, PASTEUR, 75005 Paris, France
| | - Pavel Müller
- Institute
for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette cedex, France
| |
Collapse
|
22
|
Paul S, Kiryutin AS, Guo J, Ivanov KL, Matysik J, Yurkovskaya AV, Wang X. Magnetic field effect in natural cryptochrome explored with model compound. Sci Rep 2017; 7:11892. [PMID: 28928466 PMCID: PMC5605708 DOI: 10.1038/s41598-017-10356-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 08/02/2017] [Indexed: 11/09/2022] Open
Abstract
Many animals sense the Earth's magnetic-field and use it for navigation. It is proposed that a light-dependent quantum effect in cryptochrome proteins, residing in the retina, allows for such an iron-free spin-chemical compass. The photochemical processes, spin-dynamics and its magnetic field dependence in natural cryptochrome are not fully understood by the in vivo and in vitro studies. For a deeper insight into these biophysical mechanisms in cryptochrome, we had introduced a flavin-tryptophan dyad (F10T). Here we present the magnetic field dependence of 1H photo-CIDNP NMR on F10T and a theoretical model for low-field photo-CIDNP of F10T. This model provides mixing mechanism of energy-levels and spin-dynamics at low magnetic fields. Photo-CIDNP has been observed even at Earth's magnetic field (~0.05 mT). These experiments prove F10T to be an excellent model compound establishing the key mechanism of avian-magnetoreception and provide insight into the optimal behaviour of cryptochrome at Earth's magnetic field.
Collapse
Affiliation(s)
- Shubhajit Paul
- Institut für Analytische Chemie, Universität Leipzig, Linnéstr, 3, D-04103, Leipzig, Germany
| | - Alexey S Kiryutin
- International Tomography Center, Siberian Branch of the Russian Academy of Science, Institutskaya 3a, Novosibirsk, 630090, Russia
- Novosibirsk State University, Pirogova 2, Novosibirsk, 630090, Russia
| | - Jinping Guo
- Department of Chemistry and Biology, College of Science, National University of Defense Technology, 410073, Changsha, China
| | - Konstantin L Ivanov
- International Tomography Center, Siberian Branch of the Russian Academy of Science, Institutskaya 3a, Novosibirsk, 630090, Russia
- Novosibirsk State University, Pirogova 2, Novosibirsk, 630090, Russia
| | - Jörg Matysik
- Institut für Analytische Chemie, Universität Leipzig, Linnéstr, 3, D-04103, Leipzig, Germany
| | - Alexandra V Yurkovskaya
- International Tomography Center, Siberian Branch of the Russian Academy of Science, Institutskaya 3a, Novosibirsk, 630090, Russia
- Novosibirsk State University, Pirogova 2, Novosibirsk, 630090, Russia
| | - Xiaojie Wang
- Department of Chemistry and Biology, College of Science, National University of Defense Technology, 410073, Changsha, China.
| |
Collapse
|
23
|
Giachello CN, Scrutton NS, Jones AR, Baines RA. Magnetic Fields Modulate Blue-Light-Dependent Regulation of Neuronal Firing by Cryptochrome. J Neurosci 2016; 36:10742-9. [PMID: 27798129 DOI: 10.1523/JNEUROSCI.2140-16.2016] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [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.
Collapse
|
24
|
Nohr D, Paulus B, Rodriguez R, Okafuji A, Bittl R, Schleicher E, Weber S. Bestimmung des Radikal-Radikal-Abstands in lichtaktiven Proteinen im angeregten Zustand und dessen Bedeutung für die biologische Magnetorezeption. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201700389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Daniel Nohr
- Institut für Physikalische Chemie; Albert-Ludwigs-Universität Freiburg; Albertstraße 21 79104 Freiburg Deutschland
| | - Bernd Paulus
- Institut für Physikalische Chemie; Albert-Ludwigs-Universität Freiburg; Albertstraße 21 79104 Freiburg Deutschland
| | - Ryan Rodriguez
- Institut für Physikalische Chemie; Albert-Ludwigs-Universität Freiburg; Albertstraße 21 79104 Freiburg Deutschland
| | - Asako Okafuji
- Institut für Physikalische Chemie; Albert-Ludwigs-Universität Freiburg; Albertstraße 21 79104 Freiburg Deutschland
| | - Robert Bittl
- Fachbereich Physik; Freie Universität Berlin; Arnimallee 14 14195 Berlin Deutschland
| | - Erik Schleicher
- Institut für Physikalische Chemie; Albert-Ludwigs-Universität Freiburg; Albertstraße 21 79104 Freiburg Deutschland
| | - Stefan Weber
- Institut für Physikalische Chemie; Albert-Ludwigs-Universität Freiburg; Albertstraße 21 79104 Freiburg Deutschland
| |
Collapse
|
25
|
Nohr D, Paulus B, Rodriguez R, Okafuji A, Bittl R, Schleicher E, Weber S. Determination of Radical-Radical Distances in Light-Active Proteins and Their Implication for Biological Magnetoreception. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/anie.201700389] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Daniel Nohr
- Institute of Physical Chemistry; Albert-Ludwigs-Universität Freiburg; Albertstrasse 21 79104 Freiburg Germany
| | - Bernd Paulus
- Institute of Physical Chemistry; Albert-Ludwigs-Universität Freiburg; Albertstrasse 21 79104 Freiburg Germany
| | - Ryan Rodriguez
- Institute of Physical Chemistry; Albert-Ludwigs-Universität Freiburg; Albertstrasse 21 79104 Freiburg Germany
| | - Asako Okafuji
- Institute of Physical Chemistry; Albert-Ludwigs-Universität Freiburg; Albertstrasse 21 79104 Freiburg Germany
| | - Robert Bittl
- Department of Physics; Freie Universität Berlin; Arnimallee 14 14195 Berlin Germany
| | - Erik Schleicher
- Institute of Physical Chemistry; Albert-Ludwigs-Universität Freiburg; Albertstrasse 21 79104 Freiburg Germany
| | - Stefan Weber
- Institute of Physical Chemistry; Albert-Ludwigs-Universität Freiburg; Albertstrasse 21 79104 Freiburg Germany
| |
Collapse
|
26
|
Nohr D, Franz S, Rodriguez R, Paulus B, Essen LO, Weber S, Schleicher E. Extended Electron-Transfer in Animal Cryptochromes Mediated by a Tetrad of Aromatic Amino Acids. Biophys J 2017; 111:301-311. [PMID: 27463133 DOI: 10.1016/j.bpj.2016.06.009] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 05/24/2016] [Accepted: 06/10/2016] [Indexed: 02/06/2023] Open
Abstract
The cryptochrome/photolyase protein family possesses a conserved triad of tryptophans that may act as a molecular wire to transport electrons from the protein surface to the FAD cofactor for activation and/or signaling-state formation. Members from the animal (and animal-like) cryptochrome subclade use this process in a light-induced fashion in a number of exciting responses, such as the (re-)setting of circadian rhythms or magnetoreception; however, electron-transfer pathways have not been explored in detail yet. Therefore, we present an in-depth time-resolved optical and electron-paramagnetic resonance spectroscopic study of two cryptochromes from Chlamydomonas reinhardtii and Drosophila melanogaster. The results do not only reveal the existence of a fourth, more distant aromatic amino acid that serves as a terminal electron donor in both proteins, but also show that a tyrosine is able to fulfill this very role in Chlamydomonas reinhardtii cryptochrome. Additionally, exchange of the respective fourth aromatic amino acid to redox-inactive phenylalanines still leads to light-induced radical pair formation; however, the lifetimes of these species are drastically reduced from the ms- to the μs-range. The results presented in this study open up a new chapter, to our knowledge, in the diversity of electron-transfer pathways in cryptochromes. Moreover, they could explain unique functions of animal cryptochromes, in particular their potential roles in magnetoreception because magnetic-field effects of light-induced radical pairs strongly depend on distance and orientation parameters.
Collapse
Affiliation(s)
- Daniel Nohr
- Institute of Physical Chemistry, University of Freiburg, Freiburg, Germany
| | | | - Ryan Rodriguez
- Institute of Physical Chemistry, University of Freiburg, Freiburg, Germany
| | - Bernd Paulus
- Institute of Physical Chemistry, University of Freiburg, Freiburg, Germany
| | | | - Stefan Weber
- Institute of Physical Chemistry, University of Freiburg, Freiburg, Germany
| | - Erik Schleicher
- Institute of Physical Chemistry, University of Freiburg, Freiburg, Germany.
| |
Collapse
|
27
|
Abstract
Bacterial biofilms are promising tools for functional applications as bionanomaterials.
Collapse
Affiliation(s)
- Ebuzer Kalyoncu
- UNAM – National Nanotechnology Research Center and Institute of Materials Science and Nanotechnology
- Bilkent University
- Ankara
- Turkey
| | - Recep E. Ahan
- UNAM – National Nanotechnology Research Center and Institute of Materials Science and Nanotechnology
- Bilkent University
- Ankara
- Turkey
| | - Tolga T. Olmez
- UNAM – National Nanotechnology Research Center and Institute of Materials Science and Nanotechnology
- Bilkent University
- Ankara
- Turkey
| | - Urartu Ozgur Safak Seker
- UNAM – National Nanotechnology Research Center and Institute of Materials Science and Nanotechnology
- Bilkent University
- Ankara
- Turkey
| |
Collapse
|
28
|
Abstract
The magnetic compass sense of migratory birds is thought to rely on magnetically sensitive radical pairs formed photochemically in cryptochrome proteins in the retina. An important requirement of this hypothesis is that electron spin relaxation is slow enough for the Earth's magnetic field to have a significant effect on the coherent spin dynamics of the radicals. It is generally assumed that evolutionary pressure has led to protection of the electron spins from irreversible loss of coherence in order that the underlying quantum dynamics can survive in a noisy biological environment. Here, we address this question for a structurally characterized model cryptochrome expected to share many properties with the putative avian receptor protein. To this end we combine all-atom molecular dynamics simulations, Bloch-Redfield relaxation theory and spin dynamics calculations to assess the effects of spin relaxation on the performance of the protein as a compass sensor. Both flavin-tryptophan and flavin-Z˙ radical pairs are studied (Z˙ is a radical with no hyperfine interactions). Relaxation is considered to arise from modulation of hyperfine interactions by librational motions of the radicals and fluctuations in certain dihedral angles. For Arabidopsis thaliana cryptochrome 1 (AtCry1) we find that spin relaxation implies optimal radical pair lifetimes of the order of microseconds, and that flavin-Z˙ pairs are less affected by relaxation than flavin-tryptophan pairs. Our results also demonstrate that spin relaxation in isolated AtCry1 is incompatible with the long coherence times that have been postulated to explain the disruption of the avian magnetic compass sense by weak radiofrequency magnetic fields. We conclude that a cryptochrome sensor in vivo would have to differ dynamically, if not structurally, from isolated AtCry1. Our results clearly mark the limits of the current hypothesis and lead to a better understanding of the operation of radical pair magnetic sensors in noisy biological environments.
Collapse
Affiliation(s)
- Daniel R Kattnig
- Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory, OX1 3QZ, UK.
| | | | | |
Collapse
|
29
|
Nohr D, Rodriguez R, Weber S, Schleicher E. How can EPR spectroscopy help to unravel molecular mechanisms of flavin-dependent photoreceptors? Front Mol Biosci 2015; 2:49. [PMID: 26389123 PMCID: PMC4555020 DOI: 10.3389/fmolb.2015.00049] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 08/10/2015] [Indexed: 11/25/2022] Open
Abstract
Electron paramagnetic resonance (EPR) spectroscopy is a well-established spectroscopic method for the examination of paramagnetic molecules. Proteins can contain paramagnetic moieties in form of stable cofactors, transiently formed intermediates, or spin labels artificially introduced to cysteine sites. The focus of this review is to evaluate potential scopes of application of EPR to the emerging field of optogenetics. The main objective for EPR spectroscopy in this context is to unravel the complex mechanisms of light-active proteins, from their primary photoreaction to downstream signal transduction. An overview of recent results from the family of flavin-containing, blue-light dependent photoreceptors is given. In detail, mechanistic similarities and differences are condensed from the three classes of flavoproteins, the cryptochromes, LOV (Light-oxygen-voltage), and BLUF (blue-light using FAD) domains. Additionally, a concept that includes spin-labeled proteins and examination using modern pulsed EPR is introduced, which allows for a precise mapping of light-induced conformational changes.
Collapse
Affiliation(s)
- Daniel Nohr
- Department of Physical Chemistry, Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg Freiburg, Germany
| | - Ryan Rodriguez
- Department of Physical Chemistry, Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg Freiburg, Germany
| | - Stefan Weber
- Department of Physical Chemistry, Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg Freiburg, Germany
| | - Erik Schleicher
- Department of Physical Chemistry, Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg Freiburg, Germany
| |
Collapse
|
30
|
Sure S, Torriero AAJ, Gaur A, Li LH, Chen Y, Tripathi C, Adholeya A, Ackland ML, Kochar M. Inquisition of Microcystis aeruginosa and Synechocystis nanowires: characterization and modelling. Antonie Van Leeuwenhoek 2015; 108:1213-25. [PMID: 26319534 DOI: 10.1007/s10482-015-0576-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 08/24/2015] [Indexed: 10/23/2022]
Abstract
Identification of extracellular conductive pilus-like structures (PLS) i.e. microbial nanowires has spurred great interest among scientists due to their potential applications in the fields of biogeochemistry, bioelectronics, bioremediation etc. Using conductive atomic force microscopy, we identified microbial nanowires in Microcystis aeruginosa PCC 7806 which is an aerobic, photosynthetic microorganism. We also confirmed the earlier finding that Synechocystis sp. PCC 6803 produces microbial nanowires. In contrast to the use of highly instrumented continuous flow reactors for Synechocystis reported earlier, we identified simple and optimum culture conditions which allow increased production of nanowires in both test cyanobacteria. Production of these nanowires in Synechocystis and Microcystis were found to be sensitive to the availability of carbon source and light intensity. These structures seem to be proteinaceous in nature and their diameter was found to be 4.5-7 and 8.5-11 nm in Synechocystis and M. aeruginosa, respectively. Characterization of Synechocystis nanowires by transmission electron microscopy and biochemical techniques confirmed that they are type IV pili (TFP) while nanowires in M. aeruginosa were found to be similar to an unnamed protein (GenBank : CAO90693.1). Modelling studies of the Synechocystis TFP subunit i.e. PilA1 indicated that strategically placed aromatic amino acids may be involved in electron transfer through these nanowires. This study identifies PLS from Microcystis which can act as nanowires and supports the earlier hypothesis that microbial nanowires are widespread in nature and play diverse roles.
Collapse
Affiliation(s)
- Sandeep Sure
- TERI-Deakin Nanobiotechnology Centre, TERI Gram, The Energy and Resources Institute, Gual Pahari, Gurgaon Faridabad Road, Gurgaon, 122 001, Haryana, India
| | - Angel A J Torriero
- Centre for Cellular and Molecular Biology, Deakin University, 221 Burwood Highway, Burwood, Melbourne, VIC, 3125, Australia
| | - Aditya Gaur
- TERI-Deakin Nanobiotechnology Centre, TERI Gram, The Energy and Resources Institute, Gual Pahari, Gurgaon Faridabad Road, Gurgaon, 122 001, Haryana, India
| | - Lu Hua Li
- Institute for Frontier Materials, Deakin University, Geelong Waurn Ponds Campus, Geelong, VIC, 3216, Australia
| | - Ying Chen
- Institute for Frontier Materials, Deakin University, Geelong Waurn Ponds Campus, Geelong, VIC, 3216, Australia
| | - Chandrakant Tripathi
- TERI-Deakin Nanobiotechnology Centre, TERI Gram, The Energy and Resources Institute, Gual Pahari, Gurgaon Faridabad Road, Gurgaon, 122 001, Haryana, India
| | - Alok Adholeya
- TERI-Deakin Nanobiotechnology Centre, TERI Gram, The Energy and Resources Institute, Gual Pahari, Gurgaon Faridabad Road, Gurgaon, 122 001, Haryana, India
| | - M Leigh Ackland
- Centre for Cellular and Molecular Biology, Deakin University, 221 Burwood Highway, Burwood, Melbourne, VIC, 3125, Australia
| | - Mandira Kochar
- TERI-Deakin Nanobiotechnology Centre, TERI Gram, The Energy and Resources Institute, Gual Pahari, Gurgaon Faridabad Road, Gurgaon, 122 001, Haryana, India.
| |
Collapse
|
31
|
Abstract
Tryptophan and tyrosine can form radical intermediates that enable long-range, multistep electron transfer (ET) reactions in proteins. This report describes the mechanisms of formation and quenching of a neutral tryptophan radical in azurin, a blue-copper protein that contains native tyrosine (Y108 and Y72) and tryptophan (W48) residues. A long-lived neutral tryptophan radical W48• is formed upon UV-photoexcitation of a zinc(II)-substituted azurin mutant in the presence of an external electron acceptor. The quantum yield of W48• formation (Φ) depends upon the tyrosine residues in the protein. A tyrosine-deficient mutant, Zn(II)Az48W, exhibited a value of Φ = 0.080 with a Co(III) electron acceptor. A nearly identical quantum yield was observed when the electron acceptor was the analogous tyrosine-free, copper(II) mutant; this result for the Zn(II)Az48W:Cu(II)Az48W mixture suggests there is an interprotein ET path. A single tyrosine residue at one of the native positions reduced the quantum yield to 0.062 (Y108) or 0.067 (Y72). Wild-type azurin with two tyrosine residues exhibited a quantum yield of Φ = 0.045. These data indicate that tyrosine is able to quench the tryptophan radical in azurin.
Collapse
Affiliation(s)
- Bethany C. Larson
- Department of Chemistry and Biochemistry, University of California at San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Jennifer R. Pomponio
- Department of Chemistry and Biochemistry, University of California at San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | | | - Rachel H. Kim
- Department of Chemistry and Biochemistry, University of California at San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Brian S. Leigh
- Department of Chemistry and Biochemistry, University of California at San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Michael J. Tauber
- Department of Chemistry and Biochemistry, University of California at San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Judy E. Kim
- Department of Chemistry and Biochemistry, University of California at San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| |
Collapse
|
32
|
Fudim R, Mehlhorn J, Berthold T, Weber S, Schleicher E, Kennis JTM, Mathes T. Photoinduced formation of flavin radicals in BLUF domains lacking the central glutamine. FEBS J 2015; 282:3161-74. [DOI: 10.1111/febs.13297] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 04/08/2015] [Accepted: 04/13/2015] [Indexed: 11/29/2022]
Affiliation(s)
- Roman Fudim
- Institut für Biologie/Experimentelle Biophysik; Humboldt Universität zu Berlin; Berlin Germany
| | - Jennifer Mehlhorn
- Institut für Biologie/Experimentelle Biophysik; Humboldt Universität zu Berlin; Berlin Germany
| | - Thomas Berthold
- Institut für Physikalische Chemie; Albert-Ludwigs-Universität Freiburg; Freiburg Germany
| | - Stefan Weber
- Institut für Physikalische Chemie; Albert-Ludwigs-Universität Freiburg; Freiburg Germany
- Freiburg Institute for Advanced Studies (FRIAS); Albert-Ludwigs-Universität Freiburg; Germany
| | - Erik Schleicher
- Institut für Physikalische Chemie; Albert-Ludwigs-Universität Freiburg; Freiburg Germany
- Inorganic Chemistry Laboratory; University of Oxford; UK
| | - John T. M. Kennis
- Biophysics Section; Department of Physics and Astronomy; Faculty of Sciences; VU University; Amsterdam The Netherlands
| | - Tilo Mathes
- Institut für Biologie/Experimentelle Biophysik; Humboldt Universität zu Berlin; Berlin Germany
- Biophysics Section; Department of Physics and Astronomy; Faculty of Sciences; VU University; Amsterdam The Netherlands
| |
Collapse
|
33
|
Paulus B, Bajzath C, Melin F, Heidinger L, Kromm V, Herkersdorf C, Benz U, Mann L, Stehle P, Hellwig P, Weber S, Schleicher E. Spectroscopic characterization of radicals and radical pairs in fruit fly cryptochrome - protonated and nonprotonated flavin radical-states. FEBS J 2015; 282:3175-89. [PMID: 25879256 DOI: 10.1111/febs.13299] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 03/21/2015] [Accepted: 04/14/2015] [Indexed: 01/05/2023]
Abstract
Drosophila melanogaster cryptochrome is one of the model proteins for animal blue-light photoreceptors. Using time-resolved and steady-state optical spectroscopy, we studied the mechanism of light-induced radical-pair formation and decay, and the photoreduction of the FAD cofactor. Exact kinetics on a microsecond to minutes timescale could be extracted for the wild-type protein using global analysis. The wild-type exhibits a fast photoreduction reaction from the oxidized FAD to the FAD(•-) state with a very positive midpoint potential of ~ +125 mV, although no further reduction could be observed. We could also demonstrate that the terminal tryptophan of the conserved triad, W342, is directly involved in electron transfer; however, photoreduction could not be completely inhibited in a W342F mutant. The investigation of another mutation close to the FAD cofactor, C416N, rather unexpectedly reveals accumulation of a protonated flavin radical on a timescale of several seconds. The obtained data are critically discussed with the ones obtained from another protein, Escherichia coli photolyase, and we conclude that the amino acid opposite N(5) of the isoalloxazine moiety of FAD is able to (de)stabilize the protonated FAD radical but not to significantly modulate the kinetics of any light-inducted reactions.
Collapse
Affiliation(s)
- Bernd Paulus
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Germany
| | - Csaba Bajzath
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Germany
| | - Frédéric Melin
- Laboratoire de Bioélectrochimie et Spectroscopie Université de Strasbourg, France
| | - Lorenz Heidinger
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Germany
| | - Viktoria Kromm
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Germany
| | | | - Ulrike Benz
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Germany
| | - Lisa Mann
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Germany
| | - Patricia Stehle
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Germany
| | - Petra Hellwig
- Laboratoire de Bioélectrochimie et Spectroscopie Université de Strasbourg, France
| | - Stefan Weber
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Germany
| | - Erik Schleicher
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Germany
| |
Collapse
|
34
|
Scheerer P, Zhang F, Kalms J, von Stetten D, Krauß N, Oberpichler I, Lamparter T. The class III cyclobutane pyrimidine dimer photolyase structure reveals a new antenna chromophore binding site and alternative photoreduction pathways. J Biol Chem 2015; 290:11504-14. [PMID: 25784552 DOI: 10.1074/jbc.m115.637868] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Indexed: 11/06/2022] Open
Abstract
Photolyases are proteins with an FAD chromophore that repair UV-induced pyrimidine dimers on the DNA in a light-dependent manner. The cyclobutane pyrimidine dimer class III photolyases are structurally unknown but closely related to plant cryptochromes, which serve as blue-light photoreceptors. Here we present the crystal structure of a class III photolyase termed photolyase-related protein A (PhrA) of Agrobacterium tumefaciens at 1.67-Å resolution. PhrA contains 5,10-methenyltetrahydrofolate (MTHF) as an antenna chromophore with a unique binding site and mode. Two Trp residues play pivotal roles for stabilizing MTHF by a double π-stacking sandwich. Plant cryptochrome I forms a pocket at the same site that could accommodate MTHF or a similar molecule. The PhrA structure and mutant studies showed that electrons flow during FAD photoreduction proceeds via two Trp triads. The structural studies on PhrA give a clearer picture on the evolutionary transition from photolyase to photoreceptor.
Collapse
Affiliation(s)
- Patrick Scheerer
- From the Charité, University Medicine Berlin, Institute of Medical Physics and Biophysics (CC2), AG Protein X-ray Crystallography and Signal Transduction, Charitéplatz 1, D-10117 Berlin, Germany,
| | - Fan Zhang
- the Karlsruhe Institute of Technology (KIT), Botanical Institute, Kaiserstr. 2, D-76131 Karlsruhe, Germany
| | - Jacqueline Kalms
- From the Charité, University Medicine Berlin, Institute of Medical Physics and Biophysics (CC2), AG Protein X-ray Crystallography and Signal Transduction, Charitéplatz 1, D-10117 Berlin, Germany
| | - David von Stetten
- the Structural Biology Group, European Synchroton Radiation Facility, CS 40220, F-38043 Grenoble Cedex 9, France, and
| | - Norbert Krauß
- the Queen Mary University of London, School of Biological and Chemical Sciences, Mile End Road, London E1 4NS, United Kingdom
| | - Inga Oberpichler
- the Karlsruhe Institute of Technology (KIT), Botanical Institute, Kaiserstr. 2, D-76131 Karlsruhe, Germany,
| | - Tilman Lamparter
- the Karlsruhe Institute of Technology (KIT), Botanical Institute, Kaiserstr. 2, D-76131 Karlsruhe, Germany,
| |
Collapse
|
35
|
Salahub DR, Noskov SY, Lev B, Zhang R, Ngo V, Goursot A, Calaminici P, Köster AM, Alvarez-Ibarra A, Mejía-Rodríguez D, Řezáč J, Cailliez F, de la Lande A. QM/MM calculations with deMon2k. Molecules 2015; 20:4780-812. [PMID: 25786164 DOI: 10.3390/molecules20034780] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 02/25/2015] [Accepted: 03/02/2015] [Indexed: 11/18/2022] Open
Abstract
The density functional code deMon2k employs a fitted density throughout (Auxiliary Density Functional Theory), which offers a great speed advantage without sacrificing necessary accuracy. Powerful Quantum Mechanical/Molecular Mechanical (QM/MM) approaches are reviewed. Following an overview of the basic features of deMon2k that make it efficient while retaining accuracy, three QM/MM implementations are compared and contrasted. In the first, deMon2k is interfaced with the CHARMM MM code (CHARMM-deMon2k); in the second MM is coded directly within the deMon2k software; and in the third the Chemistry in Ruby (Cuby) wrapper is used to drive the calculations. Cuby is also used in the context of constrained-DFT/MM calculations. Each of these implementations is described briefly; pros and cons are discussed and a few recent applications are described briefly. Applications include solvated ions and biomolecules, polyglutamine peptides important in polyQ neurodegenerative diseases, copper monooxygenases and ultra-rapid electron transfer in cryptochromes.
Collapse
|
36
|
Lüdemann G, Solov’yov IA, Kubař T, Elstner M. Solvent Driving Force Ensures Fast Formation of a Persistent and Well-Separated Radical Pair in Plant Cryptochrome. J Am Chem Soc 2015; 137:1147-56. [DOI: 10.1021/ja510550g] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Gesa Lüdemann
- Department
for Theoretical Chemical Biology, Institute for Physical Chemistry, Karlsruhe Institute of Technology, Kaiserstrasse 12, 76131 Karlsruhe, Germany
| | - Ilia A. Solov’yov
- Department
of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
| | - Tomáš Kubař
- Department
for Theoretical Chemical Biology, Institute for Physical Chemistry, Karlsruhe Institute of Technology, Kaiserstrasse 12, 76131 Karlsruhe, Germany
| | - Marcus Elstner
- Department
for Theoretical Chemical Biology, Institute for Physical Chemistry, Karlsruhe Institute of Technology, Kaiserstrasse 12, 76131 Karlsruhe, Germany
| |
Collapse
|
37
|
Morozova OB, Yurkovskaya AV. Modulation of the Rate of Reversible Electron Transfer in Oxidized Tryptophan and Tyrosine Containing Peptides in Acidic Aqueous Solution. J Phys Chem B 2014; 119:140-9. [DOI: 10.1021/jp511068n] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Olga B. Morozova
- International Tomography Center, Institutskaya
3a, 630090 Novosibirsk, Russia
| | - Alexandra V. Yurkovskaya
- International Tomography Center, Institutskaya
3a, 630090 Novosibirsk, Russia
- Novosibirsk State University, Pirogova
2, 630090, Novosibirsk, Russia
| |
Collapse
|
38
|
Hense A, Herman E, Oldemeyer S, Kottke T. Proton transfer to flavin stabilizes the signaling state of the blue light receptor plant cryptochrome. J Biol Chem 2014; 290:1743-51. [PMID: 25471375 DOI: 10.1074/jbc.m114.606327] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Plant cryptochromes regulate the circadian rhythm, flowering time, and photomorphogenesis in higher plants as responses to blue light. In the dark, these photoreceptors bind oxidized FAD in the photolyase homology region (PHR). Upon blue light absorption, FAD is converted to the neutral radical state, the likely signaling state, by electron transfer via a conserved tryptophan triad and proton transfer from a nearby aspartic acid. Here we demonstrate, by infrared and time-resolved UV-visible spectroscopy on the PHR domain, that replacement of the aspartic acid Asp-396 with cysteine prevents proton transfer. The lifetime of the radical is decreased by 6 orders of magnitude. This short lifetime does not permit to drive conformational changes in the C-terminal extension that have been associated with signal transduction. Only in the presence of ATP do both the wild type and mutant form a long-lived radical state. However, in the mutant, an anion radical is formed instead of the neutral radical, as found previously in animal type I cryptochromes. Infrared spectroscopic experiments demonstrate that the light-induced conformational changes of the PHR domain are conserved in the mutant despite the lack of proton transfer. These changes are not detected in the photoreduction of the non-photosensory d-amino acid oxidase to the anion radical. In conclusion, formation of the anion radical is sufficient to generate a protein response in plant cryptochromes. Moreover, the intrinsic proton transfer is required for stabilization of the signaling state in the absence of ATP.
Collapse
Affiliation(s)
- Anika Hense
- From the Physical and Biophysical Chemistry, Department of Chemistry, Bielefeld University, Universitätsstrasse 25, 33615 Bielefeld, Germany
| | - Elena Herman
- From the Physical and Biophysical Chemistry, Department of Chemistry, Bielefeld University, Universitätsstrasse 25, 33615 Bielefeld, Germany
| | - Sabine Oldemeyer
- From the Physical and Biophysical Chemistry, Department of Chemistry, Bielefeld University, Universitätsstrasse 25, 33615 Bielefeld, Germany
| | - Tilman Kottke
- From the Physical and Biophysical Chemistry, Department of Chemistry, Bielefeld University, Universitätsstrasse 25, 33615 Bielefeld, Germany
| |
Collapse
|
39
|
Williamson HR, Dow BA, Davidson VL. Mechanisms for control of biological electron transfer reactions. Bioorg Chem 2014; 57:213-221. [PMID: 25085775 PMCID: PMC4285783 DOI: 10.1016/j.bioorg.2014.06.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 06/17/2014] [Accepted: 06/20/2014] [Indexed: 10/25/2022]
Abstract
Electron transfer (ET) through and between proteins is a fundamental biological process. The rates and mechanisms of these ET reactions are controlled by the proteins in which the redox centers that donate and accept electrons reside. The protein influences the magnitudes of the ET parameters, the electronic coupling and reorganization energy that are associated with the ET reaction. The protein can regulate the rates of the ET reaction by requiring reaction steps to optimize the system for ET, leading to kinetic mechanisms of gated or coupled ET. Amino acid residues in the segment of the protein through which long range ET occurs can also modulate the ET rate by serving as staging points for hopping mechanisms of ET. Specific examples are presented to illustrate these mechanisms by which proteins control rates of ET reactions.
Collapse
Affiliation(s)
- Heather R Williamson
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32827, United States
| | - Brian A Dow
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32827, United States
| | - Victor L Davidson
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32827, United States.
| |
Collapse
|
40
|
Fedele G, Edwards MD, Bhutani S, Hares JM, Murbach M, Green EW, Dissel S, Hastings MH, Rosato E, Kyriacou CP. Genetic analysis of circadian responses to low frequency electromagnetic fields in Drosophila melanogaster. PLoS Genet 2014; 10:e1004804. [PMID: 25473952 PMCID: PMC4256086 DOI: 10.1371/journal.pgen.1004804] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 10/03/2014] [Indexed: 11/18/2022] Open
Abstract
The blue-light sensitive photoreceptor cryptochrome (CRY) may act as a magneto-receptor through formation of radical pairs involving a triad of tryptophans. Previous genetic analyses of behavioral responses of Drosophila to electromagnetic fields using conditioning, circadian and geotaxis assays have lent some support to the radical pair model (RPM). Here, we describe a new method that generates consistent and reliable circadian responses to electromagnetic fields that differ substantially from those already reported. We used the Schuderer apparatus to isolate Drosophila from local environmental variables, and observe extremely low frequency (3 to 50 Hz) field-induced changes in two locomotor phenotypes, circadian period and activity levels. These field-induced phenotypes are CRY- and blue-light dependent, and are correlated with enhanced CRY stability. Mutational analysis of the terminal tryptophan of the triad hypothesised to be indispensable to the electron transfer required by the RPM reveals that this residue is not necessary for field responses. We observe that deletion of the CRY C-terminus dramatically attenuates the EMF-induced period changes, whereas the N-terminus underlies the hyperactivity. Most strikingly, an isolated CRY C-terminus that does not encode the Tryptophan triad nor the FAD binding domain is nevertheless able to mediate a modest EMF-induced period change. Finally, we observe that hCRY2, but not hCRY1, transformants can detect EMFs, suggesting that hCRY2 is blue light-responsive. In contrast, when we examined circadian molecular cycles in wild-type mouse suprachiasmatic nuclei slices under blue light, there was no field effect. Our results are therefore not consistent with the classical Trp triad-mediated RPM and suggest that CRYs act as blue-light/EMF sensors depending on trans-acting factors that are present in particular cellular environments.
Collapse
Affiliation(s)
- Giorgio Fedele
- Department of Genetics, University of Leicester, Leicester, United Kingdom
| | - Mathew D. Edwards
- Division of Neurobiology, Medical Research Council Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Supriya Bhutani
- Department of Genetics, University of Leicester, Leicester, United Kingdom
| | - John M. Hares
- Department of Genetics, University of Leicester, Leicester, United Kingdom
| | - Manuel Murbach
- IT'IS Foundation, Zurich, Switzerland
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
| | - Edward W. Green
- Department of Genetics, University of Leicester, Leicester, United Kingdom
| | - Stephane Dissel
- Department of Genetics, University of Leicester, Leicester, United Kingdom
| | - Michael H. Hastings
- Division of Neurobiology, Medical Research Council Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Ezio Rosato
- Department of Genetics, University of Leicester, Leicester, United Kingdom
| | | |
Collapse
|
41
|
Engelhard C, Wang X, Robles D, Moldt J, Essen LO, Batschauer A, Bittl R, Ahmad M. Cellular metabolites enhance the light sensitivity of Arabidopsis cryptochrome through alternate electron transfer pathways. Plant Cell 2014; 26:4519-31. [PMID: 25428980 PMCID: PMC4277212 DOI: 10.1105/tpc.114.129809] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Cryptochromes are blue light receptors with multiple signaling roles in plants and animals. Plant cryptochrome (cry1 and cry2) biological activity has been linked to flavin photoreduction via an electron transport chain comprising three evolutionarily conserved tryptophan residues known as the Trp triad. Recently, it has been reported that cry2 Trp triad mutants, which fail to undergo photoreduction in vitro, nonetheless show biological activity in vivo, raising the possibility of alternate signaling pathways. Here, we show that Arabidopsis thaliana cry2 proteins containing Trp triad mutations indeed undergo robust photoreduction in living cultured insect cells. UV/Vis and electron paramagnetic resonance spectroscopy resolves the discrepancy between in vivo and in vitro photochemical activity, as small metabolites, including NADPH, NADH, and ATP, were found to promote cry photoreduction even in mutants lacking the classic Trp triad electron transfer chain. These metabolites facilitate alternate electron transfer pathways and increase light-induced radical pair formation. We conclude that cryptochrome activation is consistent with a mechanism of light-induced electron transfer followed by flavin photoreduction in vivo. We further conclude that in vivo modulation by cellular compounds represents a feature of the cryptochrome signaling mechanism that has important consequences for light responsivity and activation.
Collapse
Affiliation(s)
| | - Xuecong Wang
- University of Paris VI, UMR 8256 (B2A), IBPS, 75005 Paris, France
| | - David Robles
- University of Paris VI, UMR 8256 (B2A), IBPS, 75005 Paris, France
| | - Julia Moldt
- Department of Plant Physiology and Photobiology, Faculty of Biology, Philipps-University, 35032 Marburg, Germany
| | - Lars-Oliver Essen
- Biomedical Research Centre/Faculty of Chemistry, Philipps-University, 35032 Marburg, Germany
| | - Alfred Batschauer
- Department of Plant Physiology and Photobiology, Faculty of Biology, Philipps-University, 35032 Marburg, Germany
| | - Robert Bittl
- Fachbereich Physik, Free University, 14195 Berlin, Germany
| | - Margaret Ahmad
- University of Paris VI, UMR 8256 (B2A), IBPS, 75005 Paris, France Xavier University, Cincinatti, Ohio 45207
| |
Collapse
|
42
|
Cailliez F, Müller P, Gallois M, de la Lande A. ATP binding and aspartate protonation enhance photoinduced electron transfer in plant cryptochrome. J Am Chem Soc 2014; 136:12974-86. [PMID: 25157750 DOI: 10.1021/ja506084f] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Cryptochromes are flavoproteins encountered in most vegetal and animal species. They play a role of blue-light receptors in plants and in invertebrates. The putative resting state of the FAD cofactor in these proteins is its fully oxidized form, FADox. Upon blue-light excitation, the isoalloxazine ring (ISO) may undergo an ultrafast reduction by a nearby tryptophan residue W400. This primary reduction triggers a cascade of electron and proton transfers, ultimately leading to the formation of the FADH° radical. A recent experimental study has shown that the yield of FADH° formation in Arabidopsis cryptochrome can be strongly modulated by ATP binding and by pH, affecting the protonation state of D396 (proton donor to FAD°(-)). Here we provide a detailed molecular analysis of these effects by means of combined classical molecular dynamics simulations and time-dependent density functional theory calculations. When ATP is present and D396 protonated, FAD remains in close contact with W400, thereby enhancing electron transfer (ET) from W400 to ISO*. In contrast, deprotonation of D396 and absence of ATP introduce flexibility to the photoactive site prior to FAD excitation, with the consequence of increased ISO-W400 distance and diminished tunneling rate by almost two orders of magnitude. We show that under these conditions, ET from the adenine moiety of FAD becomes a competitive relaxation pathway. Overall, our data suggest that the observed effects of ATP and pH on the FAD photoreduction find their roots in the earliest stage of the photoreduction process; i.e., ATP binding and the protonation state of D396 determine the preferred pathway of ISO* relaxation.
Collapse
Affiliation(s)
- Fabien Cailliez
- Laboratoire de Chimie Physique, UMR 8000, Université Paris-Sud and CNRS , Orsay F-91405, France
| | | | | | | |
Collapse
|
43
|
Abstract
Leishmania major was proposed to either utilize haem from its host or partially synthesize the tetrapyrrole from host provided precursors. However, only indirect evidence was available for this partial late haem biosynthetic pathway. Here, we demonstrate that the LMJF_06_1280 gene of L. major encodes a HemG-type PPO (protoporphyrinogen IX oxidase) catalysing the oxidation of protoporphyrinogen IX to protoporphyrin IX. Interestingly, trypanosomatids are currently the only known eukaryotes possessing HemG-type enzymes. The LMJF_06_1280 gene forms a potential transcriptional unit with LMJF_06_1270 encoding CPO (coproporphyrinogen III oxidase) and with LMJF_06_1290 for a cytochrome b5. In vivo function of the L. major hemG gene was shown by the functional complementation of the Escherichia coli ΔhemG strain LG285. Restored haem formation in E. coli was observed using HPLC analyses. Purified recombinant L. major HemG revealed PPO activity in vitro using different ubiquinones and triphenyltetrazolium as electron acceptors. FMN was identified as the L. major HemG cofactor. Active site residues were found to be essential for HemG catalysis. These data in combination with the solved crystal structures of L. major CPO and the physiological proof of a ferrochelatase activity provide clear-cut evidence for a partial haem biosynthetic pathway in L. major.
Collapse
|
44
|
Fedele G, Green EW, Rosato E, Kyriacou CP. An electromagnetic field disrupts negative geotaxis in Drosophila via a CRY-dependent pathway. Nat Commun 2014; 5:4391. [PMID: 25019586 PMCID: PMC4104433 DOI: 10.1038/ncomms5391] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 06/13/2014] [Indexed: 11/27/2022] Open
Abstract
Many higher animals have evolved the ability to use the Earth’s magnetic field, particularly for orientation. Drosophila melanogaster also respond to electromagnetic fields (EMFs), although the reported effects are quite modest. Here we report that negative geotaxis in flies, scored as climbing, is disrupted by a static EMF, and this is mediated by cryptochrome (CRY), the blue-light circadian photoreceptor. CRYs may sense EMFs via formation of radical pairs of electrons requiring photoactivation of flavin adenine dinucleotide (FAD) bound near a triad of Trp residues, but mutation of the terminal Trp in the triad maintains EMF responsiveness in climbing. In contrast, deletion of the CRY C terminus disrupts EMF responses, indicating that it plays an important signalling role. CRY expression in a subset of clock neurons, or the photoreceptors, or the antennae, is sufficient to mediate negative geotaxis and EMF sensitivity. Climbing therefore provides a robust and reliable phenotype for studying EMF responses in Drosophila. The earth’s electromagnetic field has a modest effect on the behaviour of Drosophila melanogaster. Here, Fedele et al. use an assessment of climbing behaviour to describe how the blue-light circadian photoreceptor cryptochrome mediates a negative movement response to gravity in flies.
Collapse
Affiliation(s)
- Giorgio Fedele
- Department of Genetics, University of Leicester, Leicester LE1 7RH, UK
| | - Edward W Green
- Department of Genetics, University of Leicester, Leicester LE1 7RH, UK
| | - Ezio Rosato
- Department of Genetics, University of Leicester, Leicester LE1 7RH, UK
| | | |
Collapse
|
45
|
Du XL, Wang J, Pan WS, Liu QJ, Wang XJ, Wu WJ. Observation of magnetic field effects on transient fluorescence spectra of cryptochrome 1 from homing pigeons. Photochem Photobiol 2014; 90:989-96. [PMID: 24689535 DOI: 10.1111/php.12276] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2014] [Accepted: 03/24/2014] [Indexed: 11/28/2022]
Abstract
Cryptochromes are suggested to be involved in the bird magnetoreception based on the radical pair mechanism (RPM), a well established theory of weak magnetic field effects on chemical reactions. Two members of cryptochrome/photolyase family were found to respond to magnetic field, however, no direct responses of bird cryptochrome to magnetic field as weak as the Earth's magnetic field have been obtained so far. In this study, we used transient fluorescence spectroscopy to characterize the weak magnetic field effects of bird cryptochromes. To do this, we cloned the cryptochrome 1 gene (clCRY1) from the retina of homing pigeons (Columba livia), expressed it in insect Sf9 cells and analyzed the transient fluorescence of purified clCRY1 by application of 45-300 μT magnetic fields. The flavin adenine dinucleotide (FADox ) and glucose oxidase (GOD) in PBS buffer were set as controls which could be excited by light to generate radicals, but would not be sensitive to magnetic field. We observed that the transient fluorescence spectra of clCRY1 were sensitive to the applied magnetic field at room temperature. Our result provides a new proof of the cryptochrome-based model of avian magnetoreception in vitro.
Collapse
Affiliation(s)
- Xian-li Du
- Department of Chemistry and Biology, National University of Defense Technology, Changsha, China
| | | | | | | | | | | |
Collapse
|
46
|
Solov'yov IA, Domratcheva T, Schulten K. Separation of photo-induced radical pair in cryptochrome to a functionally critical distance. Sci Rep 2014; 4:3845. [PMID: 24457842 PMCID: PMC4894384 DOI: 10.1038/srep03845] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Accepted: 12/27/2013] [Indexed: 11/09/2022] Open
Abstract
Cryptochrome is a blue light receptor that acts as a sensor for the geomagnetic field and assists many animals in long-range navigation. The magnetoreceptor function arises from light-induced formation of a radical pair through electron transfer between a flavin cofactor (FAD) and a triad of tryptophan residues. Here, this electron transfer is investigated by quantum chemical and classical molecular dynamics calculations. The results reveal how sequential electron transfer, assisted by rearrangement of polar side groups in the cryptochrome interior, can yield a FAD-Trp radical pair state with the FAD and Trp partners separated beyond a critical distance. The large radical pair separation reached establishes cryptochrome's sensitivity to the geomagnetic field through weakening of distance-dependent exchange and dipole-dipole interactions. It is estimated that the key secondary electron transfer step can overcome in speed both recombination (electron back-transfer) and proton transfer involving the radical pair reached after primary electron transfer.
Collapse
Affiliation(s)
- Ilia A Solov'yov
- 1] Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, 405 N. Mathews Ave, Urbana Illinois 61801, USA [2] Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Tatiana Domratcheva
- Department of Biomolecular Mechanisms, Max Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany
| | - Klaus Schulten
- 1] Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, 405 N. Mathews Ave, Urbana Illinois 61801, USA [2] Department of Physics, University of Illinois at Urbana-Champaign, 1110 W. Green Street, Urbana, Illinois 61801, USA
| |
Collapse
|
47
|
Saprygina NN, Morozova OB, Grampp G, Yurkovskaya AV. Effect of Amino Group Charge on the Photooxidation Kinetics of Aromatic Amino Acids. J Phys Chem A 2013; 118:339-49. [DOI: 10.1021/jp4097919] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Natalya N. Saprygina
- International Tomography Center, Institutskaya
3a, 630090 Novosibirsk, Russia
- Novosibirsk State University, Pirogova 2, 630090 Novosibirsk, Russia
| | - Olga B. Morozova
- International Tomography Center, Institutskaya
3a, 630090 Novosibirsk, Russia
- Novosibirsk State University, Pirogova 2, 630090 Novosibirsk, Russia
| | - Günter Grampp
- Institute
of Physical and Theoretical Chemistry, Graz University of Technology, Stremayrgasse
9, 8010 Graz, Austria
| | - Alexandra V. Yurkovskaya
- International Tomography Center, Institutskaya
3a, 630090 Novosibirsk, Russia
- Novosibirsk State University, Pirogova 2, 630090 Novosibirsk, Russia
| |
Collapse
|
48
|
|
49
|
Abstract
Within the framework of the radical pair mechanism, magnetic fields may alter the rate and yields of chemical reactions involving spin-correlated radical pairs as intermediates. Such effects have been studied in detail in a variety of chemical systems both experimentally and theoretically. In recent years, there has been growing interest in whether such magnetic field effects (MFEs) also occur in biological systems, a question driven most notably by the increasing body of evidence for the involvement of such effects in the magnetic compass sense of animals. The blue-light photoreceptor cryptochrome is placed at the centre of this debate and photoexcitation of its bound flavin cofactor has indeed been shown to result in the formation of radical pairs. Here, we review studies of MFEs on free flavins in model systems as well as in blue-light photoreceptor proteins and discuss the properties that are crucial in determining the magnetosensitivity of these systems.
Collapse
Affiliation(s)
- Emrys W. Evans
- Centre for Advanced Electron Spin Resonance, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, UK
| | - Charlotte A. Dodson
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK
| | - Kiminori Maeda
- Centre for Advanced Electron Spin Resonance, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, UK
| | - Till Biskup
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104 Freiburg, Germany
| | - C. J. Wedge
- Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK
| | - Christiane R. Timmel
- Centre for Advanced Electron Spin Resonance, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, UK
| |
Collapse
|
50
|
Dodson CA, Hore PJ, Wallace MI. A radical sense of direction: signalling and mechanism in cryptochrome magnetoreception. Trends Biochem Sci 2013; 38:435-46. [PMID: 23938034 DOI: 10.1016/j.tibs.2013.07.002] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 06/26/2013] [Accepted: 07/02/2013] [Indexed: 10/26/2022]
Abstract
The remarkable phenomenon of magnetoreception in migratory birds and other organisms has fascinated biologists for decades. Much evidence has accumulated to suggest that birds sense the magnetic field of the Earth using photochemical transformations in cryptochrome flavoproteins. In the last 5 years this highly interdisciplinary field has seen advances in structural biology, biophysics, spin chemistry, and genetic studies in model organisms. We review these developments and consider how this chemical signal can be integrated into the cellular response.
Collapse
Affiliation(s)
- Charlotte A Dodson
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, UK.
| | | | | |
Collapse
|