1
|
Wörner J, Panter S, Illarionov B, Bacher A, Fischer M, Weber S. Expanding Reaction Horizons: Evidence of the 5-Deazaflavin Radical Through Photochemically Induced Dynamic Nuclear Polarization. Angew Chem Int Ed Engl 2023; 62:e202309334. [PMID: 37571931 DOI: 10.1002/anie.202309334] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 08/09/2023] [Accepted: 08/10/2023] [Indexed: 08/13/2023]
Abstract
Deazaflavins are important analogues of the naturally occurring flavins: riboflavin, flavin mononucleotide (FMN), and flavin adenine dinucleotide (FAD). The use of 5-deazaflavin as a replacement coenzyme in a number of flavoproteins has proven particularly valuable in unraveling and manipulating their reaction mechanisms. It was frequently reported that one-electron-transfer reactions in flavoproteins are impeded with 5-deazaflavin as the cofactor. Based on these findings, it was concluded that the 5-deazaflavin radical is significantly less stable compared to the respective flavin semiquinone and quickly re-oxidizes or undergoes disproportionation. The long-standing paradigm of 5-deazaflavin being solely a two-electron/hydride acceptor/donor-"a nicotinamide in flavin clothing"-needs to be re-evaluated now with the indirect observation of a one-electron-reduced (paramagnetic) species using photochemically induced dynamic nuclear polarization (photo-CIDNP) 1 H nuclear magnetic resonance (NMR) under biologically relevant conditions.
Collapse
Affiliation(s)
- Jakob Wörner
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104, Freiburg, Germany
| | - Sabrina Panter
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104, Freiburg, Germany
| | - Boris Illarionov
- Institut für Lebensmittelchemie, Universität Hamburg, Grindelallee 117, 20146, Hamburg, Germany
| | - Adelbert Bacher
- TUM School of Natural Sciences, Technische Universität München, Lichtenbergstraße 4, 85747, Garching, Germany
| | - Markus Fischer
- Institut für Lebensmittelchemie, Universität Hamburg, Grindelallee 117, 20146, Hamburg, Germany
| | - Stefan Weber
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104, Freiburg, Germany
| |
Collapse
|
2
|
Geniman MP, Morozova OB, Lukzen NN, Grampp G, Yurkovskaya AV. Marcus Cross-Relationship Probed by Time-Resolved CIDNP. Int J Mol Sci 2023; 24:13860. [PMID: 37762162 PMCID: PMC10530771 DOI: 10.3390/ijms241813860] [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: 08/09/2023] [Revised: 09/04/2023] [Accepted: 09/05/2023] [Indexed: 09/29/2023] Open
Abstract
The time-resolved CIDNP method can provide information about degenerate exchange reactions (DEEs) involving short-lived radicals. In the temperature range from 8 to 65 °C, the DEE reactions of the guanosine-5'-monophosphate anion GMP(-H)- with the neutral radical GMP(-H)•, of the N-acetyl tyrosine anion N-AcTyrO- with a neutral radical N-AcTyrO•, and of the tyrosine anion TyrO- with a neutral radical TyrO• were studied. In all the studied cases, the radicals were formed in the reaction of quenching triplet 2,2'-dipyridyl. The reorganization energies were obtained from Arrhenius plots. The rate constant of the reductive electron transfer reaction in the pair GMP(-H)•/TyrO- was determined at T = 25 °C. Rate constants of the GMP(-H)• radical reduction reactions with TyrO- and N-AcTyrO- anions calculated by the Marcus cross-relation differ from the experimental ones by two orders of magnitude. The rate constants of several other electron transfer reactions involving GMP(-H)-/GMP(-H)•, N-AcTyrO-/N-AcTyrO•, and TyrO-/TyrO• pairs calculated by cross-relation agree well with the experimental values. The rate of nuclear paramagnetic relaxation was found for the 3,5 and β-protons of TyrO• and N-AcTyrO•, the 8-proton of GMP(-H)•, and the 3,4-protons of DPH• at each temperature. In all cases, the dependences of the rate of nuclear paramagnetic relaxation on temperature are described by the Arrhenius dependence.
Collapse
Affiliation(s)
- Maksim P. Geniman
- International Tomography Center SB RAS, 630090 Novosibirsk, Russia; (M.P.G.); (O.B.M.); (N.N.L.)
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Olga B. Morozova
- International Tomography Center SB RAS, 630090 Novosibirsk, Russia; (M.P.G.); (O.B.M.); (N.N.L.)
| | - Nikita N. Lukzen
- International Tomography Center SB RAS, 630090 Novosibirsk, Russia; (M.P.G.); (O.B.M.); (N.N.L.)
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Günter Grampp
- Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremayrgasse, 9, A-8010 Graz, Austria;
| | - Alexandra V. Yurkovskaya
- International Tomography Center SB RAS, 630090 Novosibirsk, Russia; (M.P.G.); (O.B.M.); (N.N.L.)
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| |
Collapse
|
3
|
Hey D, Jethwa RB, Farag NL, Rinkel BLD, Zhao EW, Grey CP. Identifying and preventing degradation in flavin mononucleotide-based redox flow batteries via NMR and EPR spectroscopy. Nat Commun 2023; 14:5207. [PMID: 37626038 PMCID: PMC10457286 DOI: 10.1038/s41467-023-40649-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Accepted: 07/31/2023] [Indexed: 08/27/2023] Open
Abstract
While aqueous organic redox flow batteries (RFBs) represent potential solutions to large-scale grid storage, their electrolytes suffer from short lifetimes due to rapid degradation. We show how an understanding of these degradation processes can be used to dramatically improve performance, as illustrated here via a detailed study of the redox-active biomolecule, flavin mononucleotide (FMN), a molecule readily derived from vitamin B2. Via in-situ nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) we identify FMN hydrolysis products and show that these give rise to the additional plateau seen during charging of an FMN-cyanoferrate battery. The redox reactions of the hydrolysis product are not reversible, but we demonstrate that capacity is still retained even after substantial hydrolysis, albeit with reduced voltaic efficiency, FMN acting as a redox mediator. Critically, we demonstrate that degradation is mitigated and battery efficiency is substantially improved by lowering the pH to 11. Furthermore, the addition of cheap electrolyte salts to tune the pH results in a dramatic increase in solubility (above 1 M), this systematic improvement of the flavin-based system bringing RFBs one step closer to commercial viability.
Collapse
Affiliation(s)
- Dominic Hey
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Rajesh B Jethwa
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Nadia L Farag
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | | | - Evan Wenbo Zhao
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
- Magnetic Resonance Research Centre, Institute for Molecules and Materials, Radboud University, Nijmegen, The Netherlands
| | - Clare P Grey
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK.
| |
Collapse
|
4
|
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.
Collapse
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.
| |
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|