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Kim Y, Alia A, Kurle-Tucholski P, Wiebeler C, Matysik J. Electronic Structures of Radical-Pair-Forming Cofactors in a Heliobacterial Reaction Center. Molecules 2024; 29:1021. [PMID: 38474533 DOI: 10.3390/molecules29051021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 02/16/2024] [Accepted: 02/22/2024] [Indexed: 03/14/2024] Open
Abstract
Photosynthetic reaction centers (RCs) are membrane proteins converting photonic excitations into electric gradients. The heliobacterial RCs (HbRCs) are assumed to be the precursors of all known RCs, making them a compelling subject for investigating structural and functional relationships. A comprehensive picture of the electronic structure of the HbRCs is still missing. In this work, the combination of selective isotope labelling of 13C and 15N nuclei and the utilization of photo-CIDNP MAS NMR (photochemically induced dynamic nuclear polarization magic-angle spinning nuclear magnetic resonance) allows for highly enhanced signals from the radical-pair-forming cofactors. The remarkable magnetic-field dependence of the solid-state photo-CIDNP effect allows for observation of positive signals of the electron donor cofactor at 4.7 T, which is interpreted in terms of a dominant contribution of the differential relaxation (DR) mechanism. Conversely, at 9.4 T, the emissive signals mainly originate from the electron acceptor, due to the strong activation of the three-spin mixing (TSM) mechanism. Consequently, we have utilized two-dimensional homonuclear photo-CIDNP MAS NMR at both 4.7 T and 9.4 T. These findings from experimental investigations are corroborated by calculations based on density functional theory (DFT). This allows us to present a comprehensive investigation of the electronic structure of the cofactors involved in electron transfer (ET).
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Affiliation(s)
- Yunmi Kim
- Institut für Analytische Chemie, Universität Leipzig, Linnéstraße 3, D-04103 Leipzig, Germany
| | - A Alia
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2301 RA Leiden, The Netherlands
- Institut für Medizinische Physik und Biophysik, Universität Leipzig, Härtelstr. 16-18, D-04107 Leipzig, Germany
| | - Patrick Kurle-Tucholski
- Institut für Analytische Chemie, Universität Leipzig, Linnéstraße 3, D-04103 Leipzig, Germany
| | - Christian Wiebeler
- Institut für Analytische Chemie, Universität Leipzig, Linnéstraße 3, D-04103 Leipzig, Germany
- Institut für Physik, Universität Augsburg, Universitätsstraße 1, D-86159 Augsburg, Germany
| | - Jörg Matysik
- Institut für Analytische Chemie, Universität Leipzig, Linnéstraße 3, D-04103 Leipzig, Germany
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2
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Bernarding J, Bruns C, Prediger I, Mützel M, Plaumann M. Detection of sub-nmol amounts of the antiviral drug favipiravir in 19F MRI using photo-chemically induced dynamic nuclear polarization. Sci Rep 2024; 14:1527. [PMID: 38233411 PMCID: PMC10794400 DOI: 10.1038/s41598-024-51454-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 01/05/2024] [Indexed: 01/19/2024] Open
Abstract
In biological tissues, 19F magnetic resonance (MR) enables the non-invasive, background-free detection of 19F-containing biomarkers. However, the signal-to-noise ratio (SNR) is usually low because biomarkers are typically present at low concentrations. Measurements at low magnetic fields further reduce the SNR. In a proof-of-principal study we applied LED-based photo-chemically induced dynamic nuclear polarization (photo-CIDNP) to amplify the 19F signal at 0.6 T. For the first time, 19F MR imaging (MRI) and spectroscopy (MRS) of a fully biocompatible model system containing the antiviral drug favipiravir has been successfully performed. This fluorinated drug has been used to treat Ebola and COVID-19. Since the partially cyclic reaction scheme for photo-CIDNP allows for multiple data acquisitions, averaging further improved the SNR. The mean signal gain factor for 19F has been estimated to be in the order of 103. An in-plane resolution of 0.39 × 0.39 mm2 enabled the analysis of spatially varying degrees of hyperpolarization. The minimal detectable amount of favipiravir per voxel was estimated to about 500 pmol. The results show that 19F photo-CIDNP is a promising method for the non-invasive detection of suitable 19F-containing drugs and other compounds with very low levels of the substance.
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Affiliation(s)
- J Bernarding
- Institute of Biometry and Medical Informatics, Otto-von-Guericke University Magdeburg, Leipziger Strasse 44, 39120, Magdeburg, Germany.
| | - C Bruns
- Institute of Biometry and Medical Informatics, Otto-von-Guericke University Magdeburg, Leipziger Strasse 44, 39120, Magdeburg, Germany
| | - I Prediger
- Institute of Biometry and Medical Informatics, Otto-von-Guericke University Magdeburg, Leipziger Strasse 44, 39120, Magdeburg, Germany
| | - M Mützel
- Pure Devices GmbH, 97222, Rimpar, Germany
| | - M Plaumann
- Institute of Biometry and Medical Informatics, Otto-von-Guericke University Magdeburg, Leipziger Strasse 44, 39120, Magdeburg, Germany
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3
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Kurle-Tucholski P, Köhler L, Zhao Z, Link G, Wiebeler C, Matysik J. Stabilization of a flavoprotein for solid-state photo-CIDNP MAS NMR at room temperature by embedding in a glassy sugar matrix. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2023; 353:107497. [PMID: 37295281 DOI: 10.1016/j.jmr.2023.107497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 05/26/2023] [Accepted: 05/30/2023] [Indexed: 06/12/2023]
Abstract
Hyperpolarization via the solid-state photochemically induced dynamic nuclear polarization (photo-CIDNP) effect can be detected in frozen solutions of electron transfer proteins generating a radical-pair upon illumination. The effect has been observed in various natural photosynthetic reaction centers and in light-oxygen-voltage (LOV) sensing domains incorporating a flavin mononucleotide (FMN) as chromophore. In LOV domains, where a highly conserved cysteine is mutated to a flavin to interrupt its natural photochemistry, a radical-pair is generated by electron transfer from a nearby tryptophan to the photoexcited triplet state of FMN. During the photocycle, both the LOV domain and the chromophore are photochemically degraded, e.g., by the formation of singlet oxygen. This limits the time for collection of hyperpolarized nuclear magnetic resonance (NMR) data. We show that embedding of the protein into a trehalose sugar glass matrix stabilizes the protein for 13C solid-state photo-CIDNP NMR experiments which can be conducted at room temperature in a powder sample. Additionally, this preparation allows for incorporation of high amounts of protein further boosting the intensity of the detected signals from FMN and tryptophan at natural abundance. Signal assignment is aided by quantum chemical calculations of absolute shieldings. The underlying mechanism for the surprising absorption-only signal pattern is not yet understood. Comparison to calculated isotropic hyperfine couplings imply that the enhancement is not due to the classical radical-pair mechanism (RPM). Analysis of the anisotropic hyperfine couplings associated with solid-state photo-CIDNP mechanisms also show no simple correlation, suggesting a more complex underlying mechanism.
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Affiliation(s)
- Patrick Kurle-Tucholski
- Institut für Analytische Chemie, Universität Leipzig, Linnéstraße 3, D-04103 Leipzig, Germany
| | - Lisa Köhler
- Institut für Analytische Chemie, Universität Leipzig, Linnéstraße 3, D-04103 Leipzig, Germany
| | - Ziyue Zhao
- Institut für Analytische Chemie, Universität Leipzig, Linnéstraße 3, D-04103 Leipzig, Germany
| | - Gerhard Link
- Institut für Physikalische Chemie, Universität Freiburg, Albertstraße 21, D-79104 Freiburg, Germany
| | - Christian Wiebeler
- Institut für Analytische Chemie, Universität Leipzig, Linnéstraße 3, D-04103 Leipzig, Germany; Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Linnéstraße 2, D-04103 Leipzig, Germany; Institut für Physik, Universität Augsburg, Universitätsstraße 1, D-86159 Augsburg, Germany
| | - Jörg Matysik
- Institut für Analytische Chemie, Universität Leipzig, Linnéstraße 3, D-04103 Leipzig, Germany.
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Matysik J, Gerhards L, Theiss T, Timmermann L, Kurle-Tucholski P, Musabirova G, Qin R, Ortmann F, Solov'yov IA, Gulder T. Spin Dynamics of Flavoproteins. Int J Mol Sci 2023; 24:ijms24098218. [PMID: 37175925 PMCID: PMC10179055 DOI: 10.3390/ijms24098218] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 04/19/2023] [Accepted: 04/27/2023] [Indexed: 05/15/2023] Open
Abstract
This short review reports the surprising phenomenon of nuclear hyperpolarization occurring in chemical reactions, which is called CIDNP (chemically induced dynamic nuclear polarization) or photo-CIDNP if the chemical reaction is light-driven. The phenomenon occurs in both liquid and solid-state, and electron transfer systems, often carrying flavins as electron acceptors, are involved. Here, we explain the physical and chemical properties of flavins, their occurrence in spin-correlated radical pairs (SCRP) and the possible involvement of flavin-carrying SCRPs in animal magneto-reception at earth's magnetic field.
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Affiliation(s)
- Jörg Matysik
- Institut für Analytische Chemie, Universität Leipzig, Linnéstr. 3, 04103 Leipzig, Germany
| | - Luca Gerhards
- Institut für Physik, Carl von Ossietzky Universität Oldenburg, Carl-von Ossietzky-Str. 9-11, 26129 Oldenburg, Germany
| | - Tobias Theiss
- Institut für Organische Chemie, Universität Leipzig, Johannisallee 29, 04103 Leipzig, Germany
| | - Lisa Timmermann
- Institut für Organische Chemie, Universität Leipzig, Johannisallee 29, 04103 Leipzig, Germany
| | | | - Guzel Musabirova
- Institut für Analytische Chemie, Universität Leipzig, Linnéstr. 3, 04103 Leipzig, Germany
| | - Ruonan Qin
- Institut für Analytische Chemie, Universität Leipzig, Linnéstr. 3, 04103 Leipzig, Germany
| | - Frank Ortmann
- TUM School of Natural Sciences, Technische Universität München, Lichtenbergstr. 4, 85748 Garching, Germany
| | - Ilia A Solov'yov
- Institut für Physik, Carl von Ossietzky Universität Oldenburg, Carl-von Ossietzky-Str. 9-11, 26129 Oldenburg, Germany
- Research Center for Neurosensory Science, Carl von Ossietzky Universität Oldenburg, Carl-von-Ossietzky-Str. 9-11, 26129 Oldenburg, Germany
- Center for Nanoscale Dynamics (CENAD), Carl von Ossietzky Universität Oldenburg, Carl-von-Ossietzky-Str. 9-11, 26129 Oldenburg, Germany
| | - Tanja Gulder
- Institut für Organische Chemie, Universität Leipzig, Johannisallee 29, 04103 Leipzig, Germany
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5
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Mishra A, Sharma A, Kateriya S. Effect of tryptophan mutation on the structure of LOV1 domain of phototropin1 protein of Ostreococcus tauri: A combined molecular dynamics simulation and biophysical approach. Biochim Biophys Acta Gen Subj 2023; 1867:130304. [PMID: 36627087 DOI: 10.1016/j.bbagen.2023.130304] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 12/13/2022] [Accepted: 01/04/2023] [Indexed: 01/08/2023]
Abstract
BACKGROUND Light, oxygen and voltage (LOV) proteins detect blue light by formation of a covalent 'photoadduct' between the flavin chromophore and the neighboring conserved cysteine residue. LOV proteins devoid of this conserved photoactive cysteine are unable to form this 'photoadduct' upon light illumination, but they can still elicit functional response via the formation of neutral flavin radical. Recently, tryptophan residue has been shown to be the primary electron donors to the flavin excited state. METHODS Photoactive cysteine (Cys42) and tryptophan (Trp68) residues in the LOV1 domain of phototropin1 of Ostreococcus tauri (OtLOV1) was mutated to alanine and threonine respectively. Effect of these mutations have been studied using molecular dynamics simulation and spectroscopic techniques. RESULTS Molecular dynamics simulation indicated that W68T did not affect the structure of OtLOV1 protein, but C42A leads to some structural changes. An increase in the fluorescence lifetime and quantum yield values was observed for the Trp68 mutant. CONCLUSIONS An increase in the fluorescence lifetime and quantum yield of Trp68 mutant compared to the wild type protein suggests that Trp68 residue participates in quenching of the flavin excited state followed by photoexcitation. GENERAL SIGNIFICANCE Enhanced photo-physical properties of Trp68 OtLOV1 mutant might enable its use for the optogenetic and microscopic applications.
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Affiliation(s)
- Ayushi Mishra
- Laboratory of Optobiotechnology, School of Biotechnology, Jawaharlal Nehru University, New Delhi 110067, India
| | - Amit Sharma
- Multidisciplinary Centre for Advanced Research and Studies, Jamia Millia Islamia, New Delhi 110025, India
| | - Suneel Kateriya
- Laboratory of Optobiotechnology, School of Biotechnology, Jawaharlal Nehru University, New Delhi 110067, India.
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Eills J, Budker D, Cavagnero S, Chekmenev EY, Elliott SJ, Jannin S, Lesage A, Matysik J, Meersmann T, Prisner T, Reimer JA, Yang H, Koptyug IV. Spin Hyperpolarization in Modern Magnetic Resonance. Chem Rev 2023; 123:1417-1551. [PMID: 36701528 PMCID: PMC9951229 DOI: 10.1021/acs.chemrev.2c00534] [Citation(s) in RCA: 64] [Impact Index Per Article: 64.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Indexed: 01/27/2023]
Abstract
Magnetic resonance techniques are successfully utilized in a broad range of scientific disciplines and in various practical applications, with medical magnetic resonance imaging being the most widely known example. Currently, both fundamental and applied magnetic resonance are enjoying a major boost owing to the rapidly developing field of spin hyperpolarization. Hyperpolarization techniques are able to enhance signal intensities in magnetic resonance by several orders of magnitude, and thus to largely overcome its major disadvantage of relatively low sensitivity. This provides new impetus for existing applications of magnetic resonance and opens the gates to exciting new possibilities. In this review, we provide a unified picture of the many methods and techniques that fall under the umbrella term "hyperpolarization" but are currently seldom perceived as integral parts of the same field. Specifically, before delving into the individual techniques, we provide a detailed analysis of the underlying principles of spin hyperpolarization. We attempt to uncover and classify the origins of hyperpolarization, to establish its sources and the specific mechanisms that enable the flow of polarization from a source to the target spins. We then give a more detailed analysis of individual hyperpolarization techniques: the mechanisms by which they work, fundamental and technical requirements, characteristic applications, unresolved issues, and possible future directions. We are seeing a continuous growth of activity in the field of spin hyperpolarization, and we expect the field to flourish as new and improved hyperpolarization techniques are implemented. Some key areas for development are in prolonging polarization lifetimes, making hyperpolarization techniques more generally applicable to chemical/biological systems, reducing the technical and equipment requirements, and creating more efficient excitation and detection schemes. We hope this review will facilitate the sharing of knowledge between subfields within the broad topic of hyperpolarization, to help overcome existing challenges in magnetic resonance and enable novel applications.
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Affiliation(s)
- James Eills
- Institute
for Bioengineering of Catalonia, Barcelona
Institute of Science and Technology, 08028Barcelona, Spain
| | - Dmitry Budker
- Johannes
Gutenberg-Universität Mainz, 55128Mainz, Germany
- Helmholtz-Institut,
GSI Helmholtzzentrum für Schwerionenforschung, 55128Mainz, Germany
- Department
of Physics, UC Berkeley, Berkeley, California94720, United States
| | - Silvia Cavagnero
- Department
of Chemistry, University of Wisconsin, Madison, Madison, Wisconsin53706, United States
| | - Eduard Y. Chekmenev
- Department
of Chemistry, Integrative Biosciences (IBio), Karmanos Cancer Institute
(KCI), Wayne State University, Detroit, Michigan48202, United States
- Russian
Academy of Sciences, Moscow119991, Russia
| | - Stuart J. Elliott
- Molecular
Sciences Research Hub, Imperial College
London, LondonW12 0BZ, United Kingdom
| | - Sami Jannin
- Centre
de RMN à Hauts Champs de Lyon, Université
de Lyon, CNRS, ENS Lyon, Université Lyon 1, 69100Villeurbanne, France
| | - Anne Lesage
- Centre
de RMN à Hauts Champs de Lyon, Université
de Lyon, CNRS, ENS Lyon, Université Lyon 1, 69100Villeurbanne, France
| | - Jörg Matysik
- Institut
für Analytische Chemie, Universität
Leipzig, Linnéstr. 3, 04103Leipzig, Germany
| | - Thomas Meersmann
- Sir
Peter Mansfield Imaging Centre, University Park, School of Medicine, University of Nottingham, NottinghamNG7 2RD, United Kingdom
| | - Thomas Prisner
- Institute
of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic
Resonance, Goethe University Frankfurt, , 60438Frankfurt
am Main, Germany
| | - Jeffrey A. Reimer
- Department
of Chemical and Biomolecular Engineering, UC Berkeley, and Materials Science Division, Lawrence Berkeley National
Laboratory, Berkeley, California94720, United States
| | - Hanming Yang
- Department
of Chemistry, University of Wisconsin, Madison, Madison, Wisconsin53706, United States
| | - Igor V. Koptyug
- International Tomography Center, Siberian
Branch of the Russian Academy
of Sciences, 630090Novosibirsk, Russia
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7
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Zerlotti R, Losi A, Polverini E. Oxygen diffusion pathways in mutated forms of a LOV photoreceptor from Methylobacterium radiotolerans: A molecular dynamics study. Biomol Concepts 2022; 13:164-174. [DOI: 10.1515/bmc-2022-0013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 03/08/2022] [Indexed: 11/15/2022] Open
Abstract
Abstract
Mr4511 from Methylobacterium radiotolerans is a photoreceptor of the light, oxygen voltage (LOV) family, binding flavin mononucleotide (FMN) as a chromophore. It exhibits the prototypical LOV photocycle, with the reversible formation of an FMN-Cys71 adduct via fast decay of the FMN triplet state. Mr4511 has high potential as a photosensitiser for singlet oxygen (SO) upon mutation of C71. Mr4511-C71S shows a triplet lifetime (τ
T) of several hundreds of microseconds, ensuring efficient energy transfer to dioxygen to form SO. In this work, we have explored the potential diffusion pathways for dioxygen within Mr4511 using molecular dynamics (MD) simulations. The structural model of wild-type (wt) Mr4511 showed a dimeric structure stabilised by a strong leucine zipper at the two C-terminal helical ends. We then introduced in silico the C71S mutation and analysed transient and persistent oxygen channels. MD simulations indicate that the chromophore binding site is highly accessible to dioxygen. Mutations that might favour SO generation were designed based on their position with respect to FMN and the oxygen channels. In particular, the C71S-Y61T and C71S-Y61S variants showed an increased diffusion and persistence of oxygen molecules inside the binding cavity.
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Affiliation(s)
- Rocco Zerlotti
- NeuroTrans ETN Network c/o Nanion Technologies GmbH, Ganghoferstraße 70/a , 80339 München , Bayern , Germany
- Department of Mathematical, Physical and Computer Sciences, University of Parma, Parco Area delle Scienze 7/A , 43124 Parma , Italy
| | - Aba Losi
- Department of Mathematical, Physical and Computer Sciences, University of Parma, Parco Area delle Scienze 7/A , 43124 Parma , Italy
| | - Eugenia Polverini
- Department of Mathematical, Physical and Computer Sciences, University of Parma, Parco Area delle Scienze 7/A , 43124 Parma , Italy
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Ding Y, Zhao Z, Matysik J, Gärtner W, Losi A. Mapping the role of aromatic amino acids within a blue-light sensing LOV domain. Phys Chem Chem Phys 2021; 23:16767-16775. [PMID: 34319324 DOI: 10.1039/d1cp02217b] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Photosensing LOV (Light, Oxygen, Voltage) domains detect and respond to UVA/Blue (BL) light by forming a covalent adduct between the flavin chromophore and a nearby cysteine, via the decay of the flavin triplet excited state. LOV domains where the reactive cysteine has been mutated are valuable fluorescent tools for microscopy and as genetically encoded photosensitisers for reactive oxygen species. Besides being convenient tools for applications, LOV domains without the reactive cysteine (naturally occurring or engineered) can still be functionally photoactivated via formation of a neutral flavin radical. Tryptophans and tyrosines are held as the main partners as potential electron donors to the flavin excited states. In this work, we explore the relevance of aromatic amino acids in determining the photophysical features of the LOV protein Mr4511 from Methylobacterium radiotolerans by introducing point mutations into the C71S variant that does not form the covalent adduct. By using an array of spectroscopic techniques we measured the fluorescence quantum yields and lifetimes, the triplet yields and lifetimes, and the efficiency of singlet oxygen (SO) formation for eleven Mr4511 variants. Insertion of Trp residues at distances between 0.6 and 1.5 nm from the flavin chromophore results in strong quenching of the flavin excited triplet state and, at the shorter distances even of the singlet excited state. The mutation F130W (ca. 0.6 nm) completely quenches the singlet excited state, preventing triplet formation: in this case, even if the cysteine is present, the photo-adduct is not formed. Tyrosines are also quenchers for the flavin excited states, although not as efficient as Trp residues, as demonstrated with their substitution with the inert phenylalanine. For one of these variants, C71S/Y116F, we found that the quantum yield of formation for singlet oxygen is 0.44 in aqueous aerobic solution, vs 0.17 for C71S. Based on our study with Mr4511 and on literature data for other LOV domains we suggest that Trp and Tyr residues too close to the flavin chromophore (at distances less than 0.9 nm) reduce the yield of photoproduct formation and that introduction of inert Phe residues in key positions can help in developing efficient, LOV-based photosensitisers.
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Affiliation(s)
- Yonghong Ding
- Institute for Analytical Chemistry, University of Leipzig, Linnéstrasse 3, 04103 Leipzig, Germany
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9
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Matysik J, Ding Y, Kim Y, Kurle P, Yurkovskaya A, Ivanov K, Alia A. Photo-CIDNP in Solid State. APPLIED MAGNETIC RESONANCE 2021; 53:521-537. [PMID: 33840910 PMCID: PMC8021640 DOI: 10.1007/s00723-021-01322-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 02/08/2021] [Accepted: 02/11/2021] [Indexed: 05/27/2023]
Abstract
Photo-CIDNP (photo-chemically induced dynamic nuclear polarization) refers to nuclear polarization created by the spin-chemical evolution of spin-correlated radical pairs (SCRPs). This phenomenon occurs in gases, liquids and solids. Based on the solid-state photo-CIDNP effect observed under magic-angle spinning (MAS), photo-CIDNP MAS NMR has been developed as analytical method. Here we report the origin, the theory and the state of the art of this method.
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Affiliation(s)
- Jörg Matysik
- Institut für Analytische Chemie, Universität Leipzig, Linnéstr. 3, 04103 Leipzig, Germany
| | - Yonghong Ding
- Institut für Analytische Chemie, Universität Leipzig, Linnéstr. 3, 04103 Leipzig, Germany
| | - Yunmi Kim
- Institut für Analytische Chemie, Universität Leipzig, Linnéstr. 3, 04103 Leipzig, Germany
| | - Patrick Kurle
- Institut für Analytische Chemie, Universität Leipzig, Linnéstr. 3, 04103 Leipzig, Germany
| | | | - Konstantin Ivanov
- International Tomography Center, Institutskaya, 630090 Novosibirsk, Russia
| | - A. Alia
- Institut für Medizinische Physik und Biophysik, Universität Leipzig, Härtelstr. 16-18, 04107 Leipzig, Germany
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands
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