1
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Wilson CB, Qi M, Han S, Sherwin MS. Gadolinium Spin Decoherence Mechanisms at High Magnetic Fields. J Phys Chem Lett 2023; 14:10578-10584. [PMID: 37976425 PMCID: PMC10694812 DOI: 10.1021/acs.jpclett.3c01847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 10/23/2023] [Accepted: 10/24/2023] [Indexed: 11/19/2023]
Abstract
Favorable relaxation processes, high-field spectral properties, and biological compatibility have made spin-7/2 Gd3+-based spin labels an increasingly popular choice for protein structure studies using high-field electron paramagnetic resonance. However, high-field relaxation and decoherence in ensembles of half-integer high-spin systems, such as Gd3+, remain poorly understood. We report spin-lattice (T1) and phase memory (TM) relaxation times at 8.6 T (240 GHz), and we present the first comprehensive model of high-field, high-spin decoherence accounting for both the electron spin concentration and temperature. The model includes four principal mechanisms driving decoherence: energy-conserving electron spin flip-flops, direct "T1" spin-lattice relaxation-driven electron spin flip processes, indirect T1-driven flips of nearby electron spins, and nuclear spin flip-flops. Mechanistic insight into decoherence can inform the design of experiments making use of Gd3+ as spin probes or relaxivity agents and can be used to measure local average interspin distances as long as 17 nm.
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Affiliation(s)
- C. Blake Wilson
- Laboratory
of Chemical Physics, National Institute of Diabetes and Digestive
and Kidney Diseases, National Institutes
of Health, Bethesda, Maryland 20892, United States
| | - Mian Qi
- Faculty
of Chemistry and Center for Molecular Materials, Bielefeld University, 33615 Bielefeld, Germany
| | - Songi Han
- Department
of Chemistry and Biochemistry, University
of California, Santa Barbara, Santa Barbara, California 93106, United States
- Department
of Chemical Engineering, University of California,
Santa Barbara, Santa
Barbara, California 93106, United States
- Institute
for Terahertz Science and Technology, University
of California, Santa Barbara, Santa
Barbara, California 93106, United States
| | - Mark S. Sherwin
- Institute
for Terahertz Science and Technology, University
of California, Santa Barbara, Santa
Barbara, California 93106, United States
- Department
of Physics, University of California, Santa
Barbara, Santa Barbara, California 93106, United States
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2
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Teucher M, Kucher S, Timachi MH, Wilson CB, Śmiłowicz D, Stoll R, Metzler-Nolte N, Sherwin MS, Han S, Bordignon E. Spectroscopically Orthogonal Spin Labels in Structural Biology at Physiological Temperatures. J Phys Chem B 2023; 127:6668-6674. [PMID: 37490415 PMCID: PMC10405217 DOI: 10.1021/acs.jpcb.3c04497] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 07/08/2023] [Indexed: 07/27/2023]
Abstract
Electron paramagnetic resonance spectroscopy (EPR) is mostly used in structural biology in conjunction with pulsed dipolar spectroscopy (PDS) methods to monitor interspin distances in biomacromolecules at cryogenic temperatures both in vitro and in cells. In this context, spectroscopically orthogonal spin labels were shown to increase the information content that can be gained per sample. Here, we exploit the characteristic properties of gadolinium and nitroxide spin labels at physiological temperatures to study side chain dynamics via continuous wave (cw) EPR at X band, surface water dynamics via Overhauser dynamic nuclear polarization at X band and short-range distances via cw EPR at high fields. The presented approaches further increase the accessible information content on biomolecules tagged with orthogonal labels providing insights into molecular interactions and dynamic equilibria that are only revealed under physiological conditions.
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Affiliation(s)
- Markus Teucher
- Faculty
of Chemistry and Biochemistry, Ruhr University
of Bochum, Bochum 44801, Germany
| | - Svetlana Kucher
- Faculty
of Chemistry and Biochemistry, Ruhr University
of Bochum, Bochum 44801, Germany
- Department
of Physical Chemistry, University of Geneva, Genève 1211, Switzerland
| | - M. Hadi Timachi
- Faculty
of Chemistry and Biochemistry, Ruhr University
of Bochum, Bochum 44801, Germany
| | - C. Blake Wilson
- Department
of Physics, University of California, Santa
Barbara, Santa
Barbara, California 93106, United States
- Institute
for Terahertz Science and Technology, University
of California, Santa Barbara, Santa
Barbara, California 93106, United States
| | - Dariusz Śmiłowicz
- Faculty
of Chemistry and Biochemistry, Ruhr University
of Bochum, Bochum 44801, Germany
| | - Raphael Stoll
- Faculty
of Chemistry and Biochemistry, Ruhr University
of Bochum, Bochum 44801, Germany
| | - Nils Metzler-Nolte
- Faculty
of Chemistry and Biochemistry, Ruhr University
of Bochum, Bochum 44801, Germany
| | - Mark S. Sherwin
- Department
of Physics, University of California, Santa
Barbara, Santa
Barbara, California 93106, United States
- Institute
for Terahertz Science and Technology, University
of California, Santa Barbara, Santa
Barbara, California 93106, United States
| | - Songi Han
- Institute
for Terahertz Science and Technology, University
of California, Santa Barbara, Santa
Barbara, California 93106, United States
- Department
of Chemistry and Biochemistry, University
of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Enrica Bordignon
- Faculty
of Chemistry and Biochemistry, Ruhr University
of Bochum, Bochum 44801, Germany
- Department
of Physical Chemistry, University of Geneva, Genève 1211, Switzerland
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3
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Dubroca T, Wang X, Mentink-Vigier F, Trociewitz B, Starck M, Parker D, Sherwin MS, Hill S, Krzystek J. Terahertz EPR spectroscopy using a 36-tesla high-homogeneity series-connected hybrid magnet. J Magn Reson 2023; 353:107480. [PMID: 37331305 DOI: 10.1016/j.jmr.2023.107480] [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] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 04/24/2023] [Accepted: 05/13/2023] [Indexed: 06/20/2023]
Abstract
Electron Paramagnetic Resonance (EPR) is a powerful technique to study materials and biological samples on an atomic scale. High-field EPR in particular enables extracting very small g-anisotropies in organic radicals and half-filled 3d and 4f metal ions such as MnII (3d5) or GdIII (4f7), and resolving EPR signals from unpaired spins with very close g-values, both of which provide high-resolution details of the local atomic environment. Before the recent commissioning of the high-homogeneity Series Connected Hybrid magnet (SCH, superconducting + resistive) at the National High Magnetic Field Laboratory (NHMFL), the highest-field, high-resolution EPR spectrometer available was limited to 25 T using a purely resistive "Keck" magnet at the NHMFL. Herein, we report the first EPR experiments performed using the SCH magnet capable of reaching the field of 36 T, corresponding to an EPR frequency of 1 THz for g = 2. The magnet's intrinsic homogeneity (25 ppm, that is 0.9 mT at 36 T over 1 cm diameter, 1 cm length cylinder) was previously established by NMR. We characterized the magnet's temporal stability (5 ppm, which is 0.2 mT at 36 T over one-minute, the typical acquisition time) using 2,2-diphenyl-1-picrylhydrazyl (DPPH). This high resolution enables resolving the weak g-anisotropy of 1,3-bis(diphenylene)-2-phenylallyl (BDPA), Δg = 2.5 × 10-4 obtained from measurements at 932 GHz and 33 T. Subsequently, we recorded EPR spectra at multiple frequencies for two GdIII complexes with potential applications as spin labels. We demonstrated a significant reduction in line broadening in Gd[DTPA], attributed to second order zero field splitting, and a resolution enhancement of g-tensor anisotropy for Gd[sTPATCN]-SL.
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Affiliation(s)
- Thierry Dubroca
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA.
| | - Xiaoling Wang
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA; Center for Molecular Magnetic Quantum Materials, University of Florida, Gainesville, FL 32611, USA
| | - Frédéric Mentink-Vigier
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA
| | - Bianca Trociewitz
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA
| | - Matthieu Starck
- Department of Chemistry, University of Durham, Durham DH13LE, UK
| | - David Parker
- Department of Chemistry, University of Durham, Durham DH13LE, UK
| | - Mark S Sherwin
- Department of Physics, University of California Santa Barbara, CA 93106, USA
| | - Stephen Hill
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA; Center for Molecular Magnetic Quantum Materials, University of Florida, Gainesville, FL 32611, USA; Department of Physics, Florida State University, Tallahassee FL 32306, USA
| | - J Krzystek
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA.
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4
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Gerhards L, Nielsen C, Kattnig DR, Hore PJ, Solov'yov IA. Modeling spin relaxation in complex radical systems using MolSpin. J Comput Chem 2023. [PMID: 37186467 DOI: 10.1002/jcc.27120] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 04/07/2023] [Accepted: 04/11/2023] [Indexed: 05/17/2023]
Abstract
Spin relaxation is an important aspect of the spin dynamics of free radicals and can have a significant impact on the outcome of their spin-selective reactions. Examples range from the use of radicals as spin qubits in quantum information processing to the radical pair reactions in proteins that may allow migratory birds to sense the direction of the Earth's magnetic field. Accurate modeling of spin relaxation, however, is non-trivial. Bloch-Redfield-Wangsness theory derives a quantum mechanical master equation from system-bath interactions in the Markovian limit that provides a comprehensive framework for describing spin relaxation. Unfortunately, the construction of the master equation is system-specific and often resource-heavy. To address this challenge, we introduce a generalized and efficient implementation of BRW theory as a new feature of the spin dynamics toolkit MolSpin which offers an easy-to-use approach for studying systems of reacting radicals of varying complexity.
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Affiliation(s)
- Luca Gerhards
- Institute of Physics, Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany
| | - Claus Nielsen
- Research & Development Department, Unicontrol, Odense, Denmark
| | - Daniel R Kattnig
- Department of Physics and Living Systems Institute, University of Exeter, Exeter, UK
| | - P J Hore
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford, UK
| | - Ilia A Solov'yov
- Institute of Physics, Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany
- Research Center for Neurosensory Science, Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany
- Center for Nanoscale Dynamics (CENAD), Institut für Physik, Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany
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5
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Schray D, Westerbeck D, Braun J, Lan Y, Gómez-Coca S, Wernsdorfer W, Ruiz E, Anson CE, Schnack J, Powell AK. Fe-Gd Ferromagnetic Cyclic Coordination Cluster [Fe III4Gd III4(teaH) 8(N 3) 8(H 2O)] with Magnetic Anisotropy─Theory and Experiment. Inorg Chem 2023; 62:6642-6648. [PMID: 37068219 DOI: 10.1021/acs.inorgchem.3c00042] [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: 04/19/2023]
Abstract
The synthesis, structural, and magnetic characterization of [FeIII4LnIII4(teaH)8(N3)8(H2O)] (Ln = Gd and Y) and the previously reported isostructural Dy analogue are discussed. The commonly held belief that both FeIII and GdIII can be regarded as isotropic ions is shown to be an oversimplification. This conclusion is derived from the magnetic data for the YIII analogue in terms of the zero-field splitting seen for FeIII and from the fact that the magnetic data for the new GdIII analogue can only be fit employing an additional anisotropy term for the GdIII ions. Furthermore, the Fe4Gd4 ring shows slow relaxation of magnetization. Our analysis of the experimental magnetic data employs both density functional theory as well as the finite-temperature Lanczos method which finally enables us to provide an almost perfect fit of magnetocaloric properties.
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Affiliation(s)
- Dirk Schray
- Institute of Inorganic Chemistry (AOC), Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131 Karlsruhe, Germany
| | - Dennis Westerbeck
- Fakultät für Physik, Universität Bielefeld, Postfach 100131, 33501 Bielefeld, Germany
| | - Jonas Braun
- Institute of Inorganic Chemistry (AOC), Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131 Karlsruhe, Germany
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Herrmann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Yanhua Lan
- Institute of Inorganic Chemistry (AOC), Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131 Karlsruhe, Germany
| | - Silvia Gómez-Coca
- Departament de Química Inorgànica and Institut de Recerca de Química Teòrica i Computacional, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain
| | - Wolfgang Wernsdorfer
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Herrmann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
- Physikalisches Institut (PHI), Karlsruhe Institute of Technology, Wolfgang-Gaede-Str. 1, 76131 Karlsruhe, Germany
- Institute for Quantum Materials and Technologies (IQMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Eliseo Ruiz
- Departament de Química Inorgànica and Institut de Recerca de Química Teòrica i Computacional, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain
| | - Christopher E Anson
- Institute of Inorganic Chemistry (AOC), Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131 Karlsruhe, Germany
| | - Jürgen Schnack
- Fakultät für Physik, Universität Bielefeld, Postfach 100131, 33501 Bielefeld, Germany
| | - Annie K Powell
- Institute of Inorganic Chemistry (AOC), Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131 Karlsruhe, Germany
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Herrmann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
- Institute for Quantum Materials and Technologies (IQMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
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6
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Maity S, Price BD, Wilson CB, Mukherjee A, Starck M, Parker D, Wilson MZ, Lovett JE, Han S, Sherwin MS. Triggered Functional Dynamics of AsLOV2 by Time-Resolved Electron Paramagnetic Resonance at High Magnetic Fields. Angew Chem Int Ed Engl 2023; 62:e202212832. [PMID: 36638360 DOI: 10.1002/anie.202212832] [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: 09/26/2022] [Revised: 01/06/2023] [Accepted: 01/09/2023] [Indexed: 01/15/2023]
Abstract
We present time-resolved Gd-Gd electron paramagnetic resonance (TiGGER) at 240 GHz for tracking inter-residue distances during a protein's mechanical cycle in the solution state. TiGGER makes use of Gd-sTPATCN spin labels, whose favorable qualities include a spin-7/2 EPR-active center, short linker, narrow intrinsic linewidth, and virtually no anisotropy at high fields (8.6 T) when compared to nitroxide spin labels. Using TiGGER, we determined that upon light activation, the C-terminus and N-terminus of AsLOV2 separate in less than 1 s and relax back to equilibrium with a time constant of approximately 60 s. TiGGER revealed that the light-activated long-range mechanical motion is slowed in the Q513A variant of AsLOV2 and is correlated to the similarly slowed relaxation of the optically excited chromophore as described in recent literature. TiGGER has the potential to valuably complement existing methods for the study of triggered functional dynamics in proteins.
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Affiliation(s)
- Shiny Maity
- Dept. of Chemistry and Biochemistry, Univ. of California, Santa Barbara, CA 93106, USA
| | - Brad D Price
- Dept. of Physics, Univ. of California, Santa Barbara, CA 93106, USA
| | - C Blake Wilson
- Dept. of Physics, Univ. of California, Santa Barbara, CA 93106, USA.,Laboratory of Chemical Physics, Nat. Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD 20892-0520, USA
| | - Arnab Mukherjee
- Dept. of Chemical Engineering, Univ. of California, Santa Barbara, CA 93106, USA
| | | | - David Parker
- Dept. of Chemistry, Univ. of Durham, Durham, DH1 3LE, UK
| | - Maxwell Z Wilson
- Dept. of Molecular, Cellular, and Developmental Biology, Univ. of California, Santa Barbara, CA 93106, USA
| | - Janet E Lovett
- School of Physics and Astronomy and the Biomedical Sciences Research Complex, Univ. of St. Andrews, St. Andrews, KY16 9SS, UK
| | - Songi Han
- Dept. of Chemistry and Biochemistry, Univ. of California, Santa Barbara, CA 93106, USA
| | - Mark S Sherwin
- Dept. of Physics, Univ. of California, Santa Barbara, CA 93106, USA
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7
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Chen H, Manvell AS, Kubus M, Dunstan MA, Lorusso G, Gracia D, Jørgensen MSB, Kegnæs S, Wilhelm F, Rogalev A, Evangelisti M, Pedersen KS. Towards frustration in Eu(II) Archimedean tessellations. Chem Commun (Camb) 2023; 59:1609-1612. [PMID: 36692932 DOI: 10.1039/d2cc06224k] [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: 12/23/2022]
Abstract
Self-assembly of trans-{EuI2} nodes and ditopic ligands leads to isoreticular 2D frameworks featuring a rare, non-kagome Archimedean tessellation. The topology and intra-layer Eu(II)-Eu(II) antiferromagnetic interactions provide the prerequisites for geometrical spin frustration, which, due to the spin state degeneracy, is key for novel phenomena such as enhanced magnetic refrigeration.
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Affiliation(s)
- Hua Chen
- Department of Chemistry, Technical University of Denmark, Kongens Lyngby, DK-2800, Denmark.
| | - Anna S Manvell
- Department of Chemistry, Technical University of Denmark, Kongens Lyngby, DK-2800, Denmark.
| | - Mariusz Kubus
- Department of Chemistry, Technical University of Denmark, Kongens Lyngby, DK-2800, Denmark.
| | - Maja A Dunstan
- Department of Chemistry, Technical University of Denmark, Kongens Lyngby, DK-2800, Denmark.
| | - Giulia Lorusso
- CNR-Institute for Microelectronics and Microsystems, Bologna Unit, Bologna 40129, Italy
| | - David Gracia
- Instituto de Nanociencia y Materiales de Aragón, Departamento de Física de la Materia Condensada, CSIC-Universidad de Zaragoza, Zaragoza 50009, Spain
| | - Mike S B Jørgensen
- Department of Chemistry, Technical University of Denmark, Kongens Lyngby, DK-2800, Denmark.
| | - Søren Kegnæs
- Department of Chemistry, Technical University of Denmark, Kongens Lyngby, DK-2800, Denmark.
| | - Fabrice Wilhelm
- European Synchrotron Radiation Facility, BP 220, Grenoble Cedex 9 38043, France
| | - Andrei Rogalev
- European Synchrotron Radiation Facility, BP 220, Grenoble Cedex 9 38043, France
| | - Marco Evangelisti
- Instituto de Nanociencia y Materiales de Aragón, Departamento de Física de la Materia Condensada, CSIC-Universidad de Zaragoza, Zaragoza 50009, Spain
| | - Kasper S Pedersen
- Department of Chemistry, Technical University of Denmark, Kongens Lyngby, DK-2800, Denmark.
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8
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Ossadnik D, Kuzin S, Qi M, Yulikov M, Godt A. A Gd III-Based Spin Label at the Limits for Linewidth Reduction through Zero-Field Splitting Optimization. Inorg Chem 2023; 62:408-432. [PMID: 36525400 DOI: 10.1021/acs.inorgchem.2c03531] [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: 12/23/2022]
Abstract
The remarkably narrow central line in the electron paramagnetic resonance spectrum and the very weak zero-field splitting (ZFS) make [GdIII(NO3Pic)] ([GdIII(TPATCN)]) an attractive starting point for the development of spin labels. For retaining the narrow line of this parent complex when modifying it with a substituent enabling bioconjugation, alkyl with a somehow remote functional group as a substituent at the picolinate moiety was found to be highly suitable because ZFS stayed weak, even if the threefold axial symmetry was broken. The ZFS is so weak that hyperfine coupling and/or g-value variations noticeably determine the linewidth in Q band and higher fields when the biomolecule is protonated, which is the standard situation, and in W band and higher fields for the protonated complex in a fully deuterated surrounding. Clearly, [NDSE-{GdIII(NO3Pic)}], a spin label targeting the cysteines in a peptide, is at a limit of linewidth narrowing through ZFS minimization. The labeling reaction is highly chemoselective and, applied to a polyproline with two cysteine units, it took no more than a minute at 7 °C and pH 7.8. Subsequent disulfide scrambling is very slow and can therefore be prevented. Double electron-electron resonance and relaxation-induced dipolar modulation enhancement applied to the spin-labeled polyproline proved the spin label useful for distance determination in peptides.
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Affiliation(s)
- Daniel Ossadnik
- Faculty of Chemistry and Center for Molecular Materials (CM2), Bielefeld University, Universitätsstraße 25, 33615Bielefeld, Germany
| | - Sergei Kuzin
- Laboratory of Physical Chemistry, Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 2, 8093Zurich, Switzerland
| | - Mian Qi
- Faculty of Chemistry and Center for Molecular Materials (CM2), Bielefeld University, Universitätsstraße 25, 33615Bielefeld, Germany
| | - Maxim Yulikov
- Laboratory of Physical Chemistry, Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 2, 8093Zurich, Switzerland
| | - Adelheid Godt
- Faculty of Chemistry and Center for Molecular Materials (CM2), Bielefeld University, Universitätsstraße 25, 33615Bielefeld, Germany
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9
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Scherer A, Yao X, Qi M, Wiedmaier M, Godt A, Drescher M. Increasing the Modulation Depth of Gd III-Based Pulsed Dipolar EPR Spectroscopy (PDS) with Porphyrin-Gd III Laser-Induced Magnetic Dipole Spectroscopy. J Phys Chem Lett 2022; 13:10958-10964. [PMID: 36399541 PMCID: PMC9720741 DOI: 10.1021/acs.jpclett.2c02138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 07/08/2022] [Accepted: 10/03/2022] [Indexed: 06/16/2023]
Abstract
Distance determination with pulsed EPR has become an important technique for the structural investigation of biomacromolecules, with double electron-electron resonance spectroscopy (DEER) as the most important method. GdIII-based spin labels are one of the most frequently used spin labels for DEER owing to their stability against reduction, high magnetic moment, and absence of orientation selection. A disadvantage of GdIII-GdIII DEER is the low modulation depth due to the broad EPR spectrum of GdIII. Here, we introduce laser-induced magnetic dipole spectroscopy (LaserIMD) with a spin pair consisting of GdIII(PymiMTA) and a photoexcited porphyrin as an alternative technique. We show that the excited state of the porphyrin is not disturbed by the presence of the GdIII complex and that herewith modulation depths of almost 40% are possible. This is significantly higher than the value of 7.2% that was achieved with GdIII-GdIII DEER.
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Affiliation(s)
- Andreas Scherer
- Department
of Chemistry and Konstanz Research School Chemical Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Xuemei Yao
- Faculty
of Chemistry and Center of Molecular Materials (CM2), Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Mian Qi
- Faculty
of Chemistry and Center of Molecular Materials (CM2), Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Max Wiedmaier
- Department
of Chemistry and Konstanz Research School Chemical Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Adelheid Godt
- Faculty
of Chemistry and Center of Molecular Materials (CM2), Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Malte Drescher
- Department
of Chemistry and Konstanz Research School Chemical Biology, University of Konstanz, 78457 Konstanz, Germany
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10
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Elliott SJ, Duff BB, Taylor-Hughes AR, Cheney DJ, Corley JP, Paul S, Brookfield A, Pawsey S, Gajan D, Aspinall HC, Lesage A, Blanc F. Off-the-Shelf Gd(NO 3) 3 as an Efficient High-Spin Metal Ion Polarizing Agent for Magic Angle Spinning Dynamic Nuclear Polarization. J Phys Chem B 2022; 126:6281-6289. [PMID: 35973071 PMCID: PMC9421651 DOI: 10.1021/acs.jpcb.2c04184] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Magic angle spinning nuclear magnetic resonance spectroscopy experiments are widely employed in the characterization of solid media. The approach is incredibly versatile but deleteriously suffers from low sensitivity, which may be alleviated by adopting dynamic nuclear polarization methods, resulting in large signal enhancements. Paramagnetic metal ions such as Gd3+ have recently shown promising results as polarizing agents for 1H, 13C, and 15N nuclear spins. We demonstrate that the widely available and inexpensive chemical agent Gd(NO3)3 achieves significant signal enhancements for the 13C and 15N nuclear sites of [2-13C,15N]glycine at 9.4 T and ∼105 K. Analysis of the signal enhancement profiles at two magnetic fields, in conjunction with electron paramagnetic resonance data, reveals the solid effect to be the dominant signal enhancement mechanism. The signal amplification obtained paves the way for efficient dynamic nuclear polarization without the need for challenging synthesis of Gd3+ polarizing agents.
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Affiliation(s)
- Stuart J Elliott
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, United Kingdom
| | - Benjamin B Duff
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, United Kingdom.,Stephenson Institute for Renewable Energy, University of Liverpool, Liverpool L69 7ZD, United Kingdom
| | | | - Daniel J Cheney
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, United Kingdom
| | - John P Corley
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, United Kingdom
| | - Subhradip Paul
- DNP MAS NMR Facility, Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham NG7 3RD, United Kingdom
| | - Adam Brookfield
- Department of Chemistry and Photon Science Institute, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Shane Pawsey
- Bruker BioSpin Corporation, Billerica, Massachusetts 01821, United States
| | - David Gajan
- Université de Lyon, Centre de Résonance Magnétique Nucléaire à Très Hauts Champs (UMR 5082, CNRS/ENS Lyon/UCBL), 69100 Villeurbanne, France
| | - Helen C Aspinall
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, United Kingdom
| | - Anne Lesage
- Université de Lyon, Centre de Résonance Magnétique Nucléaire à Très Hauts Champs (UMR 5082, CNRS/ENS Lyon/UCBL), 69100 Villeurbanne, France
| | - Frédéric Blanc
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, United Kingdom.,Stephenson Institute for Renewable Energy, University of Liverpool, Liverpool L69 7ZD, United Kingdom
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11
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Rao Y, Palumbo CT, Venkatesh A, Keener M, Stevanato G, Chauvin AS, Menzildjian G, Kuzin S, Yulikov M, Jeschke G, Lesage A, Mazzanti M, Emsley L. Design Principles for the Development of Gd(III) Polarizing Agents for Magic Angle Spinning Dynamic Nuclear Polarization. J Phys Chem C Nanomater Interfaces 2022; 126:11310-11317. [PMID: 35865791 PMCID: PMC9289950 DOI: 10.1021/acs.jpcc.2c01721] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Nuclear magnetic resonance suffers from an intrinsically low sensitivity, which can be overcome by dynamic nuclear polarization (DNP). Gd(III) complexes are attractive exogenous polarizing agents for magic angle spinning (MAS) DNP due to their high chemical stability in contrast to nitroxide-based radicals. However, even the state-of-the-art Gd(III) complexes have so far provided relatively low DNP signal enhancements of ca. 36 in comparison to standard DNP biradicals, which show enhancements of over 200. Here, we report a series of new Gd(III) complexes for DNP and show that the observed DNP enhancements of the new and existing Gd(III) complexes are inversely proportional to the square of the zero-field splitting (ZFS) parameter D, which is in turn determined by the ligand-type and the local coordination environment. The experimental DNP enhancements at 9.4 T and the ZFS parameters measured with pulsed electron paramagnetic resonance (EPR) spectroscopy agree with the above model, paving the way for the development of more efficient Gd(III) polarizing agents.
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Affiliation(s)
- Yu Rao
- Laboratory
of Magnetic Resonance, Institut des Sciences et Ingénierie
Chimiques, École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Chad T. Palumbo
- Group
of Coordination Chemistry, Institut des Sciences et Ingénierie
Chimiques, École Polytechnique Fédérale
de Lausanne (EPFL, CH-1015 Lausanne, Switzerland
| | - Amrit Venkatesh
- Laboratory
of Magnetic Resonance, Institut des Sciences et Ingénierie
Chimiques, École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Megan Keener
- Group
of Coordination Chemistry, Institut des Sciences et Ingénierie
Chimiques, École Polytechnique Fédérale
de Lausanne (EPFL, CH-1015 Lausanne, Switzerland
| | - Gabriele Stevanato
- Laboratory
of Magnetic Resonance, Institut des Sciences et Ingénierie
Chimiques, École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Anne-Sophie Chauvin
- Group
of Coordination Chemistry, Institut des Sciences et Ingénierie
Chimiques, École Polytechnique Fédérale
de Lausanne (EPFL, CH-1015 Lausanne, Switzerland
| | - Georges Menzildjian
- Laboratory
of Magnetic Resonance, Institut des Sciences et Ingénierie
Chimiques, École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Sergei Kuzin
- Laboratory
of Physical Chemistry, Department of Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Maxim Yulikov
- Laboratory
of Physical Chemistry, Department of Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Gunnar Jeschke
- Laboratory
of Physical Chemistry, Department of Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Anne Lesage
- Centre
de RMN à Très Hauts Champs, Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1), 69100 Villeurbanne, France
| | - Marinella Mazzanti
- Group
of Coordination Chemistry, Institut des Sciences et Ingénierie
Chimiques, École Polytechnique Fédérale
de Lausanne (EPFL, CH-1015 Lausanne, Switzerland
| | - Lyndon Emsley
- Laboratory
of Magnetic Resonance, Institut des Sciences et Ingénierie
Chimiques, École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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12
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Abstract
Different types of spin labels are currently available for structural studies of biomolecules both in vitro and in cells using Electron Paramagnetic Resonance (EPR) and pulse dipolar spectroscopy (PDS). Each type of label has its own advantages and disadvantages, that will be addressed in this chapter. The spectroscopically distinct properties of the labels have fostered new applications of PDS aimed to simultaneously extract multiple inter-label distances on the same sample. In fact, combining different labels and choosing the optimal strategy to address their inter-label distances can increase the information content per sample, and this is pivotal to better characterize complex multi-component biomolecular systems. In this review, we provide a brief background of the spectroscopic properties of the four most common orthogonal spin labels for PDS measurements and focus on the various methods at disposal to extract homo- and hetero-label distances in proteins. We also devote a section to possible artifacts arising from channel crosstalk and provide few examples of applications in structural biology.
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13
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Fadeeva IV, Deyneko DV, Barbaro K, Davydova GA, Sadovnikova MA, Murzakhanov FF, Fomin AS, Yankova VG, Antoniac IV, Barinov SM, Lazoryak BI, Rau JV. Influence of Synthesis Conditions on Gadolinium-Substituted Tricalcium Phosphate Ceramics and Its Physicochemical, Biological, and Antibacterial Properties. Nanomaterials 2022; 12:852. [PMID: 35269340 PMCID: PMC8912835 DOI: 10.3390/nano12050852] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 02/28/2022] [Accepted: 03/01/2022] [Indexed: 01/27/2023]
Abstract
Gadolinium-containing calcium phosphates are promising contrast agents for various bioimaging modalities. Gadolinium-substituted tricalcium phosphate (TCP) powders with 0.51 wt% of gadolinium (0.01Gd-TCP) and 5.06 wt% of (0.1Gd-TCP) were synthesized by two methods: precipitation from aqueous solutions of salts (1) (Gd-TCP-pc) and mechano-chemical activation (2) (Gd-TCP-ma). The phase composition of the product depends on the synthesis method. The product of synthesis (1) was composed of β-TCP (main phase, 96%), apatite/chlorapatite (2%), and calcium pyrophosphate (2%), after heat treatment at 900 °C. The product of synthesis (2) was represented by β-TCP (main phase, 73%), apatite/chlorapatite (20%), and calcium pyrophosphate (7%), after heat treatment at 900 °C. The substitution of Ca2+ ions by Gd3+ in both β-TCP (main phase) and apatite (admixture) phases was proved by the electron paramagnetic resonance technique. The thermal stability and specific surface area of the Gd-TCP powders synthesized by two methods were significantly different. The method of synthesis also influenced the size and morphology of the prepared Gd-TCP powders. In the case of synthesis route (1), powders with particle sizes of tens of nanometers were obtained, while in the case of synthesis (2), the particle size was hundreds of nanometers, as revealed by transmission electron microscopy. The Gd-TCP ceramics microstructure investigated by scanning electron microscopy was different depending on the synthesis route. In the case of (1), ceramics with grains of 1–50 μm, pore sizes of 1–10 µm, and a bending strength of about 30 MPa were obtained; in the case of (2), the ceramics grain size was 0.4–1.4 μm, the pore size was 2 µm, and a bending strength of about 39 MPa was prepared. The antimicrobial activity of powders was tested for four bacteria (S. aureus, E. coli, S. typhimurium, and E. faecalis) and one fungus (C. albicans), and there was roughly 30% of inhibition of the micro-organism’s growth. The metabolic activity of the NCTC L929 cell and viability of the human dental pulp stem cell study demonstrated the absence of toxic effects for all the prepared ceramic materials doped with Gd ions, with no difference for the synthesis route.
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14
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Amrutha K, Kathirvelu V. Interpretation of EPR and optical spectra of Ni(II) ions in crystalline lattices at ambient temperature. Magn Reson Chem 2022; 60:414-421. [PMID: 34859492 DOI: 10.1002/mrc.5237] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 11/24/2021] [Accepted: 11/25/2021] [Indexed: 06/13/2023]
Abstract
Many biologically important paramagnetic metal ions are characterized by electron paramagnetic resonance (EPR) spectroscopy to use as spin probes to investigate the structure and function of biomolecules. Though nickel(II) ions are an essential trace element and part of many biomolecules, the EPR properties are least understood. Herein, the EPR and optical absorption spectra measured at 300 K for Ni(II) ions diluted in two different diamagnetic hosts are investigated and reported. The EPR spectrum of a polycrystalline Ni/Mg(3-methylpyrazole)6 (ClO4 )2 [Ni/MMPC] shows two transitions at X-band frequency (~9.5 GHz), suggesting the zero-field splitting parameter (D) is larger than the resonance field of the free electron (Ho ). This incomplete and complex spectrum is successfully analyzed to obtain EPR parameters. The EPR spectrum of the polycrystalline Ni/Zn(pyrazole)6 (NO3 )2 [Ni/ZPN] shows a triplet spectrum indicating D < Ho . A detailed analysis of single-crystal EPR data yielded the spin Hamiltonian parameters. The optical absorption spectra are deconvoluted to understand the symmetry of the coordination environment in the complex.
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Affiliation(s)
- Kamalon Amrutha
- Department of Applied Sciences, National Institute of Technology Goa, Ponda, India
| | - Velavan Kathirvelu
- Department of Applied Sciences, National Institute of Technology Goa, Ponda, India
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15
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Ansari KU, Rasamsetty A, Kumar P, Shukla P, Tripathi S, Wasim M, Shanmugam M. Magneto-thermal and magnetization relaxation dynamics of a family of di-nuclear lanthanide complexes. Polyhedron 2022; 212:115613. [DOI: 10.1016/j.poly.2021.115613] [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: 11/19/2022]
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16
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Starck M, Fradgley JD, De Rosa DF, Batsanov AS, Papa M, Taylor MJ, Lovett JE, Lutter JC, Allen MJ, Parker D. Versatile Para-Substituted Pyridine Lanthanide Coordination Complexes Allow Late Stage Tailoring of Complex Function. Chemistry 2021; 27:17921-17927. [PMID: 34705302 PMCID: PMC8688332 DOI: 10.1002/chem.202103243] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [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: 09/07/2021] [Indexed: 12/28/2022]
Abstract
A series of cationic and neutral p-Br and p-NO2 pyridine substituted Eu(III) and Gd(III) coordination complexes serve as versatile synthetic intermediates. Nucleophilic aromatic substitution occurs readily at the para position under mild conditions, allowing C-N and C-C bond forming reactions to take place, permitting the introduction of azide, amino and alkynyl substituents. For Eu(III) complexes, this approach allows late stage tuning of absorption and emission spectral properties, exemplified by the lowering of the energy of an LMCT transition accompanied by a reduction in the Eu-Npy bond length. Additionally, these complexes provide direct access to the corresponding Eu(II) analogues. With the Gd(III) series, the nature of the p-substituent does not significantly change the EPR properties (linewidth, relaxation times), as required for their development as EPR spin probes that can be readily conjugated to biomolecules under mild conditions.
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Affiliation(s)
- Matthieu Starck
- Department of ChemistryDurham UniversitySouth RoadDurhamDH1 3LEUK
| | - Jack D. Fradgley
- Department of ChemistryDurham UniversitySouth RoadDurhamDH1 3LEUK
| | | | | | - Maria Papa
- SUPASchool of Physics and Astronomy and BSRCUniversity of St AndrewsNorth HaughSt AndrewsKY16 9SSUK
| | - Michael J. Taylor
- SUPASchool of Physics and Astronomy and BSRCUniversity of St AndrewsNorth HaughSt AndrewsKY16 9SSUK
| | - Janet E. Lovett
- SUPASchool of Physics and Astronomy and BSRCUniversity of St AndrewsNorth HaughSt AndrewsKY16 9SSUK
| | - Jacob C. Lutter
- Department of ChemistryWayne State University5101 Cass AvenueDetroitMI 48202USA
| | - Matthew J. Allen
- Department of ChemistryWayne State University5101 Cass AvenueDetroitMI 48202USA
| | - David Parker
- Department of ChemistryDurham UniversitySouth RoadDurhamDH1 3LEUK
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17
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Gompa TP, Greer SM, Rice NT, Jiang N, Telser J, Ozarowski A, Stein BW, La Pierre HS. High-Frequency and -Field Electron Paramagnetic Resonance Spectroscopic Analysis of Metal-Ligand Covalency in a 4f 7 Valence Series (Eu 2+, Gd 3+, and Tb 4+). Inorg Chem 2021; 60:9064-9073. [PMID: 34106710 DOI: 10.1021/acs.inorgchem.1c01062] [Citation(s) in RCA: 6] [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] [Indexed: 01/09/2023]
Abstract
The recent isolation of molecular tetravalent lanthanide complexes has enabled renewed exploration of the effect of oxidation state on the single-ion properties of the lanthanide ions. Despite the isotropic nature of the 8S ground state in a tetravalent terbium complex, [Tb(NP(1,2-bis-tBu-diamidoethane)(NEt2))4], preliminary X-band electron paramagnetic resonance (EPR) measurements on tetravalent terbium complexes show rich spectra with broad resonances. The complexity of these spectra highlights the limits of conventional X-band EPR for even qualitative determination of zero-field splitting (ZFS) in these complexes. Therefore, we report the synthesis and characterization of a novel valence series of 4f7 molecular complexes spanning three oxidation states (Eu2+, Gd3+, and Tb4+) featuring a weak-field imidophosphorane ligand system, and employ high-frequency and -field electron paramagnetic resonance (HFEPR) to obtain quantitative values for ZFS across this valence series. The series was designed to minimize deviation in the first coordination sphere from the pseudotetrahedral geometry in order to directly interrogate the role of metal identity and charge on the complexes' electronic structures. These HFEPR studies are supported by crystallographic analysis and quantum-chemical calculations to assess the relative covalent interactions in each member of this valence series and the effect of the oxidation state on the splitting of the ground state and first excited state.
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Affiliation(s)
| | - Samuel M Greer
- Los Alamos National Laboratory (LANL), Los Alamos, New Mexico 87545, United States
| | | | | | - Joshua Telser
- Department of Biological, Physical and Health Sciences, Roosevelt University, Chicago, Illinois 60605, United States
| | - Andrew Ozarowski
- National High Magnetic Field Laboratory (NHMFL), Florida State University, Tallahassee, Florida 32310, United States
| | - Benjamin W Stein
- Los Alamos National Laboratory (LANL), Los Alamos, New Mexico 87545, United States
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18
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Ivanin SN, Buz’ko VY, Sokolov ME, Magomadova MA, Panyushkin VT. STRUCTURE AND PROPERTIES OF THE MIXED-LIGAND COMPLEX COMPOUND OF GADOLINIUM STEARATE WITH BENZOYLTRIFLUOROACETONE. J STRUCT CHEM+ 2021. [DOI: 10.1134/s0022476621040077] [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]
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19
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Abstract
Gd(III) complexes are currently established as spin labels for structural studies of biomolecules using pulse dipolar electron paramagnetic resonance (PD-EPR) techniques. This has been achieved by the availability of medium- and high-field spectrometers, understanding the spin physics underlying the spectroscopic properties of high spin Gd(III) (S=7/2) pairs and their dipolar interaction, the design of well-defined model compounds and optimization of measurement techniques. In addition, a variety of Gd(III) chelates and labeling schemes have allowed a broad scope of applications. In this review, we provide a brief background of the spectroscopic properties of Gd(III) pertinent for effective PD-EPR measurements and focus on the various labels available to date. We report on their use in PD-EPR applications and highlight their pros and cons for particular applications. We also devote a section to recent in-cell structural studies of proteins using Gd(III), which is an exciting new direction for Gd(III) spin labeling.
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Affiliation(s)
- Angeliki Giannoulis
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Yasmin Ben-Ishay
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Daniella Goldfarb
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel.
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20
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21
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Morales-Guevara R, Fuentes JA, Paez-Hernández D, Carreño A. The role of substituted pyridine Schiff bases as ancillary ligands in the optical properties of a new series of fac-rhenium( i) tricarbonyl complexes: a theoretical view. RSC Adv 2021; 11:37181-37193. [PMID: 35496390 PMCID: PMC9043815 DOI: 10.1039/d1ra05737e] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 12/01/2021] [Accepted: 11/01/2021] [Indexed: 11/21/2022] Open
Abstract
Over the last few years, luminescent Re(i) tricarbonyl complexes have been increasingly proposed as fluorophores suitable for fluorescence microscopy to visualize biological structures and cells. In this sense, incorporating an asymmetrical pyridine Schiff base (PSB) as the ancillary ligand strongly modifies the staining and luminescent properties of Re(i) tricarbonyl complexes. In this work, we analyzed two series of Re(i) tricarbonyl complexes with their respective PSB ligands: (1) fac-[Re(CO)3(2,2′-bpy)(PSB)]1+ and (2) fac-[Re(CO)3(4,4′-bis(ethoxycarbonyl)-2,2′-bpy)(PSB)]1+, where the PSB exhibits substitutions at positions 4 or 6 in the phenolic ring with methyl or halogen substituents. Thus, we performed computational relativistic DFT and TDDFT studies to determine their optical properties. The ten complexes analyzed showed absorption in the visible light range. Furthermore, our analyses, including zero-field splitting (ZFS), allowed us to determine that the low-lying excited state locates below the 3LLCT states. Interestingly, seven of the ten analyzed complexes, whose corresponding PSB harbors an intramolecular hydrogen bond (IHB), exhibited luminescent emission that could be suitable for biological purposes: large Stokes shift, emission in the range 600–700 nm and τ in the order of 10−2 to 10−3 s. Conversely, the three complexes lacking the IHB due to two halogen substituents in the corresponding PSB showed a predicted emission with the lowest triplet excited state energy entering the NIR region. The main differences in the complexes' photophysical behavior have been explained by the energy gap law and time-resolved luminescence. These results emphasize the importance of choosing suitable substituents at the 4 and 6 positions in the phenolic ring of the PSB, which determine the presence of the IHB since they modulate the luminescence properties of the Re(i) core. Therefore, this study could predict Re(i) tricarbonyl complexes' properties, considering the desired emission features for biological and other applications. Over the last few years, luminescent Re(i) tricarbonyl complexes have been increasingly proposed as fluorophores suitable for fluorescence microscopy to visualize biological structures and cells.![]()
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Affiliation(s)
- Rosaly Morales-Guevara
- Universidad Andres Bello, Programa de Doctorado en Físicoquímica Molecular, Facultad de Ciencias Exactas, Santiago, Chile
- Laboratory of Organometallic Synthesis, Center of Applied NanoSciences (CANS), Facultad de Ciencias Exactas, Universidad Andres Bello, República 330, Santiago, Chile
| | - Juan A. Fuentes
- Laboratorio de Genética y Patogénesis Bacteriana, Facultad de Ciencias de la Vida, Universidad Andres Bello, República 330, Santiago, Chile
| | - Dayán Paez-Hernández
- Universidad Andres Bello, Programa de Doctorado en Físicoquímica Molecular, Facultad de Ciencias Exactas, Santiago, Chile
- Laboratory of Organometallic Synthesis, Center of Applied NanoSciences (CANS), Facultad de Ciencias Exactas, Universidad Andres Bello, República 330, Santiago, Chile
| | - Alexander Carreño
- Universidad Andres Bello, Programa de Doctorado en Físicoquímica Molecular, Facultad de Ciencias Exactas, Santiago, Chile
- Laboratory of Organometallic Synthesis, Center of Applied NanoSciences (CANS), Facultad de Ciencias Exactas, Universidad Andres Bello, República 330, Santiago, Chile
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22
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Soetbeer J, Millen M, Zouboulis K, Hülsmann M, Godt A, Polyhach Y, Jeschke G. Dynamical decoupling in water-glycerol glasses: a comparison of nitroxides, trityl radicals and gadolinium complexes. Phys Chem Chem Phys 2021; 23:5352-5369. [PMID: 33635938 DOI: 10.1039/d1cp00055a] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Our previous study on nitroxides in o-terphenyl (OTP) revealed two separable decoherence processes at low temperatures, best captured by the sum of two stretched exponentials (SSE) model. Dynamical decoupling (DD) extends both associated dephasing times linearly for 1 to 5 refocusing pulses [Soetbeer et al., Phys. Chem. Chem. Phys., 2018, 20, 1615]. Here we demonstrate an analogous DD behavior of water-soluble nitroxides in water-glycerol glass by using nitroxide and/or solvent deuteration for component assignment. Compared to the conventional Hahn experiment, we show that Carr-Purcell and Uhrig DD schemes are superior in resolving and identifying active dephasing mechanisms. Thereby, we observe a partial coherence loss to intramolecular nitroxide and trityl nuclei that can be alleviated, while the zero field splitting-induced losses for gadolinium labels cannot be refocused and contribute even at the central transition of this spin-7/2 system. Independent of the studied spin system, Uhrig DD leads to a characteristic convex dephasing envelope in both protonated water-glycerol and OTP glass, thus outperforming the Carr-Purcell scheme.
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Affiliation(s)
- Janne Soetbeer
- Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland.
| | - Marthe Millen
- Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland.
| | - Konstantin Zouboulis
- Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland.
| | - Miriam Hülsmann
- Bielefeld University, Department of Chemistry, Universitätsstr. 25, D-33615 Bielefeld, Germany
| | - Adelheid Godt
- Bielefeld University, Department of Chemistry, Universitätsstr. 25, D-33615 Bielefeld, Germany
| | - Yevhen Polyhach
- Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland.
| | - Gunnar Jeschke
- Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland.
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23
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Miao Q, Zurlo E, de Bruin D, Wondergem JAJ, Timmer M, Blok A, Heinrich D, Overhand M, Huber M, Ubbink M. A Two-Armed Probe for In-Cell DEER Measurements on Proteins*. Chemistry 2020; 26:17128-17133. [PMID: 33200852 PMCID: PMC7839491 DOI: 10.1002/chem.202002743] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [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: 06/06/2020] [Revised: 08/27/2020] [Indexed: 12/21/2022]
Abstract
The application of double electron‐electron resonance (DEER) with site‐directed spin labeling (SDSL) to measure distances in proteins and protein complexes in living cells puts rigorous restraints on the spin‐label. The linkage and paramagnetic centers need to resist the reducing conditions of the cell. Rigid attachment of the probe to the protein improves precision of the measured distances. Here, three two‐armed GdIII complexes, GdIII‐CLaNP13a/b/c were synthesized. Rather than the disulfide linkage of most other CLaNP molecules, a thioether linkage was used to avoid reductive dissociation of the linker. The doubly GdIII labeled N55C/V57C/K147C/T151C variants of T4Lysozyme were measured by 95 GHz DEER. The constructs were measured in vitro, in cell lysate and in Dictyostelium discoideum cells. Measured distances were 4.5 nm, consistent with results from paramagnetic NMR. A narrow distance distribution and typical modulation depth, also in cell, indicate complete and durable labeling and probe rigidity due to the dual attachment sites.
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Affiliation(s)
- Qing Miao
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, Einsteinweg 55, 2333, CC, Leiden, The Netherlands
| | - Enrico Zurlo
- Department of Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, PO box 9504, 2300, RA, Leiden, The Netherlands
| | - Donny de Bruin
- Department of Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, PO box 9504, 2300, RA, Leiden, The Netherlands
| | - Joeri A J Wondergem
- Department of Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, PO box 9504, 2300, RA, Leiden, The Netherlands
| | - Monika Timmer
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, Einsteinweg 55, 2333, CC, Leiden, The Netherlands
| | - Anneloes Blok
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, Einsteinweg 55, 2333, CC, Leiden, The Netherlands
| | - Doris Heinrich
- Department of Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, PO box 9504, 2300, RA, Leiden, The Netherlands.,Fraunhofer Institute for Silicate Research ISC, 97082, Würzburg, Germany
| | - Mark Overhand
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, Einsteinweg 55, 2333, CC, Leiden, The Netherlands
| | - Martina Huber
- Department of Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, PO box 9504, 2300, RA, Leiden, The Netherlands
| | - Marcellus Ubbink
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, Einsteinweg 55, 2333, CC, Leiden, The Netherlands
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24
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EL Mkami H, Hunter R, Cruickshank P, Taylor M, Lovett J, Feintuch A, Qi M, Godt A, Smith G. High-sensitivity Gd 3+-Gd 3+ EPR distance measurements that eliminate artefacts seen at short distances. Magn Reson (Gott) 2020; 1:301-313. [PMID: 37904818 PMCID: PMC10500690 DOI: 10.5194/mr-1-301-2020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 11/18/2020] [Indexed: 11/01/2023]
Abstract
Gadolinium complexes are attracting increasing attention as spin labels for EPR dipolar distance measurements in biomolecules and particularly for in-cell measurements. It has been shown that flip-flop transitions within the central transition of the high-spin Gd3 + ion can introduce artefacts in dipolar distance measurements, particularly when measuring distances less than 3 nm. Previous work has shown some reduction of these artefacts through increasing the frequency separation between the two frequencies required for the double electron-electron resonance (DEER) experiment. Here we use a high-power (1 kW), wideband, non-resonant system operating at 94 GHz to evaluate DEER measurement protocols using two stiff Gd(III) rulers, consisting of two b i s -Gd3 + -PyMTA complexes, with separations of 2.1 nm and 6.0 nm, respectively. We show that by avoiding the - 1 2 → 1 2 central transition completely, and placing both the pump and the observer pulses on either side of the central transition, we can now observe apparently artefact-free spectra and narrow distance distributions, even for a Gd-Gd distance of 2.1 nm. Importantly we still maintain excellent signal-to-noise ratio and relatively high modulation depths. These results have implications for in-cell EPR measurements at naturally occurring biomolecule concentrations.
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Affiliation(s)
- Hassane EL Mkami
- SUPA, School of Physics and Astronomy, University of St Andrews, St
Andrews, KY16 9SS, UK
| | - Robert I. Hunter
- SUPA, School of Physics and Astronomy, University of St Andrews, St
Andrews, KY16 9SS, UK
| | - Paul A. S. Cruickshank
- SUPA, School of Physics and Astronomy, University of St Andrews, St
Andrews, KY16 9SS, UK
| | - Michael J. Taylor
- SUPA, School of Physics and Astronomy, University of St Andrews, St
Andrews, KY16 9SS, UK
| | - Janet E. Lovett
- SUPA, School of Physics and Astronomy, University of St Andrews, St
Andrews, KY16 9SS, UK
| | - Akiva Feintuch
- Department of Chemical Physics, Weizmann Institute of Science,
Rehovot, Israel
| | - Mian Qi
- Faculty of Chemistry and Center of Molecular Materials (CM2),
Bielefeld University, Universitätsstraße 25, 33615 Bielefeld,
Germany
| | - Adelheid Godt
- Faculty of Chemistry and Center of Molecular Materials (CM2),
Bielefeld University, Universitätsstraße 25, 33615 Bielefeld,
Germany
| | - Graham M. Smith
- SUPA, School of Physics and Astronomy, University of St Andrews, St
Andrews, KY16 9SS, UK
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25
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Mathivathanan L, Rogez G, Ben Amor N, Robert V, Raptis RG, Boudalis AK. Origin of Ferromagnetism and Magnetic Anisotropy in a Family of Copper(II) Triangles. Chemistry 2020; 26:12769-12784. [DOI: 10.1002/chem.202001028] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Indexed: 11/11/2022]
Affiliation(s)
- Logesh Mathivathanan
- Department of Chemistry and Biochemistry and the Biomolecular Sciences Institute Florida International University Miami FL 33199 USA
| | - Guillaume Rogez
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS) CNRS/Université de Strasbourg UMR 7504 67000 Strasbourg France
| | - Nadia Ben Amor
- Laboratoire de Chimie et Physique Quantiques UMR 5626 CNRS/Université Paul Sabatier—Bat. 3R1B4 118 route de Narbonne 31062, Cedex 09 Toulouse France
| | - Vincent Robert
- Institut de Chimie de Strasbourg (UMR 7177, CNRS-Unistra) Université de Strasbourg 4 rue Blaise Pascal, CS 90032 67081 Strasbourg France
| | - Raphael G. Raptis
- Department of Chemistry and Biochemistry and the Biomolecular Sciences Institute Florida International University Miami FL 33199 USA
| | - Athanassios K. Boudalis
- Institut de Chimie de Strasbourg (UMR 7177, CNRS-Unistra) Université de Strasbourg 4 rue Blaise Pascal, CS 90032 67081 Strasbourg France
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26
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Mouchel Dit Leguerrier D, Barré R, Bryden M, Imbert D, Philouze C, Jarjayes O, Luneau D, Molloy JK, Thomas F. Structural and spectroscopic investigations of nine-coordinate redox active lanthanide complexes with a pincer O,N,O ligand. Dalton Trans 2020; 49:8238-8246. [PMID: 32510087 DOI: 10.1039/d0dt01388a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The lanthanide complexes EuL3, GdL3, YbL3 and LuL3 of the N,N'-bis(2-hydroxy-di-3,5-tert-butylphenyl)amine were prepared. The X-Ray crystal structures of GdL3 and LuL3 demonstrated a nine-coordinate sphere with three ligand molecules under their anionic diamagnetic form (Cat-N-BQ)-. The complexes showed three oxidation events (Eox11/2 = 0.15-0.16 V, E1/22 = 0.51-55 V, and E1/23 = 0.75-0.78 V vs. Fc+/Fc) via cyclic voltammetry, corresponding to the successive oxidation of the aminophenolate moeities to iminosemiquinone species. The complexes GdL3 and YbL3 were characterized by EPR spectroscopy, allowing for the determination of the zero field splitting (ZFS) parameters in the first case. The monocations (LnL3)+ and monoanions (LnL3)- were electrochemically generated (Ln = Eu, Gd, Yb, Lu), as well as the dications YbL32+ and LuL32+. The spins are antiferromagnetically exchange coupled in the diradical species LuL32+ (|D| = 260 MHz, E = 0). All the complexes (incl. neutral) possess a strong absorption band in the NIR region (730-840 nm, ε > 19 mM-1 cm-1) corresponding to ligand-based transitions.
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27
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López Plá JM, Boudalis AK, Telser J, Raptis RG. Chromium(III)-pyrazole complexes. X-Ray crystal structures, 1H NMR investigation of ligand fluxional behavior and EPR studies. Inorganica Chim Acta 2020; 502:119299. [DOI: 10.1016/j.ica.2019.119299] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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28
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Azarkh M, Gast P, Mason AB, Groenen EJJ, Mathies G. Analysis of the EPR spectra of transferrin: the importance of a zero-field-splitting distribution and 4 th-order terms. Phys Chem Chem Phys 2019; 21:16937-16948. [PMID: 31339131 DOI: 10.1039/c9cp02626f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Multi-frequency EPR spectroscopy can provide high-level structural information on high-spin Fe3+ sites in proteins and enzymes. Unfortunately, analysis of the EPR spectra of these spin systems is hindered by the presence of broad distributions in the zero-field-splitting (ZFS) parameters, which reflect conformational heterogeneity of the iron sites. We present the analysis of EPR spectra of high-spin Fe3+ bound to human serum transferrin. We apply a method termed the grid-of-errors to extract the distributions of the individual ZFS parameters from EPR spectra recorded in the high-field limit at a microwave frequency of 275 GHz. Study of a series of transferrin variants shows that the ZFS distributions are as characteristic of the structure of a high-spin Fe3+ site as the ZFS parameters themselves. Simulations based on the extracted ZFS distributions reproduce spectra recorded at 34 GHz (Q band) and 9.7 GHz (X band), including subtle variations that were previously difficult to quantify. The X-band spectrum of transferrin shows a characteristic double peak, which has puzzled researchers for decades. We show that the double peak is uniquely related to the term B4-3O4-3(S) in the spin Hamiltonian. Our method is generally applicable in the analysis of spectra that arise from a broad distribution of parameters.
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Affiliation(s)
- Mykhailo Azarkh
- Department of Chemistry, University of Konstanz, 78464 Konstanz, Germany.
| | - Peter Gast
- Department of Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, PO Box 9504, 2300 RA Leiden, The Netherlands
| | - Anne B Mason
- Department of Biochemistry, University of Vermont College of Medicine, Burlington, VT 05405, USA
| | - Edgar J J Groenen
- Department of Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, PO Box 9504, 2300 RA Leiden, The Netherlands
| | - Guinevere Mathies
- Department of Chemistry, University of Konstanz, 78464 Konstanz, Germany.
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29
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Stevanato G, Kubicki DJ, Menzildjian G, Chauvin AS, Keller K, Yulikov M, Jeschke G, Mazzanti M, Emsley L. A Factor Two Improvement in High-Field Dynamic Nuclear Polarization from Gd(III) Complexes by Design. J Am Chem Soc 2019; 141:8746-8751. [DOI: 10.1021/jacs.9b03723] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Gabriele Stevanato
- Laboratory of
Magnetic Resonance, Institut des Sciences et Ingéniere Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Dominik Józef Kubicki
- Laboratory of
Magnetic Resonance, Institut des Sciences et Ingéniere Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Georges Menzildjian
- Laboratory of
Magnetic Resonance, Institut des Sciences et Ingéniere Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Anne-Sophie Chauvin
- Group of Coordination
Chemistry, Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Katharina Keller
- Laboratory of Inorganic
Chemistry, Department of Chemistry, Laboratory, ETH Zurich, 8093 Zurich, Switzerland
| | - Maxim Yulikov
- Laboratory of Inorganic
Chemistry, Department of Chemistry, Laboratory, ETH Zurich, 8093 Zurich, Switzerland
| | - Gunnar Jeschke
- Laboratory of Inorganic
Chemistry, Department of Chemistry, Laboratory, ETH Zurich, 8093 Zurich, Switzerland
| | - Marinella Mazzanti
- Group of Coordination
Chemistry, Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Lyndon Emsley
- Laboratory of
Magnetic Resonance, Institut des Sciences et Ingéniere Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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30
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Shah A, Roux A, Starck M, Mosely JA, Stevens M, Norman DG, Hunter RI, El Mkami H, Smith GM, Parker D, Lovett JE. A Gadolinium Spin Label with Both a Narrow Central Transition and Short Tether for Use in Double Electron Electron Resonance Distance Measurements. Inorg Chem 2019; 58:3015-3025. [DOI: 10.1021/acs.inorgchem.8b02892] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Anokhi Shah
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, U.K
- BSRC, University of St Andrews, St Andrews KY16 9ST, U.K
| | - Amandine Roux
- Department of Chemistry, Durham University, South Road, Durham DH1 3LE, U.K
| | - Matthieu Starck
- Department of Chemistry, Durham University, South Road, Durham DH1 3LE, U.K
| | - Jackie A. Mosely
- Department of Chemistry, Durham University, South Road, Durham DH1 3LE, U.K
| | - Michael Stevens
- College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, U.K
| | - David G. Norman
- College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, U.K
| | - Robert I. Hunter
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, U.K
| | - Hassane El Mkami
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, U.K
| | - Graham M. Smith
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, U.K
| | - David Parker
- Department of Chemistry, Durham University, South Road, Durham DH1 3LE, U.K
| | - Janet E. Lovett
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, U.K
- BSRC, University of St Andrews, St Andrews KY16 9ST, U.K
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31
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Ritsch I, Hintz H, Jeschke G, Godt A, Yulikov M. Improving the accuracy of Cu(ii)–nitroxide RIDME in the presence of orientation correlation in water-soluble Cu(ii)–nitroxide rulers. Phys Chem Chem Phys 2019; 21:9810-9830. [DOI: 10.1039/c8cp06573j] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Detailed analysis of artefacts in the Cu(ii)–nitroxide RIDME experiments, related to orientation averaging, echo-crossing, ESEEM and background-correction is presented.
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Affiliation(s)
- Irina Ritsch
- Laboratory of Physical Chemistry
- Department of Chemistry and Applied Bioscience
- ETH Zurich
- 8093 Zurich
- Switzerland
| | - Henrik Hintz
- Faculty of Chemistry and Center for Molecular Materials (CM2)
- Bielefeld University
- 33615 Bielefeld
- Germany
| | - Gunnar Jeschke
- Laboratory of Physical Chemistry
- Department of Chemistry and Applied Bioscience
- ETH Zurich
- 8093 Zurich
- Switzerland
| | - Adelheid Godt
- Faculty of Chemistry and Center for Molecular Materials (CM2)
- Bielefeld University
- 33615 Bielefeld
- Germany
| | - Maxim Yulikov
- Laboratory of Physical Chemistry
- Department of Chemistry and Applied Bioscience
- ETH Zurich
- 8093 Zurich
- Switzerland
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32
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Keller K, Qi M, Gmeiner C, Ritsch I, Godt A, Jeschke G, Savitsky A, Yulikov M. Intermolecular background decay in RIDME experiments. Phys Chem Chem Phys 2019; 21:8228-8245. [DOI: 10.1039/c8cp07815g] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Theoretical and experimental studies of the RIDME background reveal electron and nuclear spectral diffusion contributions.
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Affiliation(s)
- Katharina Keller
- Laboratory of Physical Chemistry
- Department of Chemistry and Applied Biosciences
- ETH Zurich
- 8093 Zurich
- Switzerland
| | - Mian Qi
- Faculty of Chemistry and Center for Molecular Materials (CM2)
- Bielefeld University
- 33615 Bielefeld
- Germany
| | - Christoph Gmeiner
- Laboratory of Physical Chemistry
- Department of Chemistry and Applied Biosciences
- ETH Zurich
- 8093 Zurich
- Switzerland
| | - Irina Ritsch
- Laboratory of Physical Chemistry
- Department of Chemistry and Applied Biosciences
- ETH Zurich
- 8093 Zurich
- Switzerland
| | - Adelheid Godt
- Faculty of Chemistry and Center for Molecular Materials (CM2)
- Bielefeld University
- 33615 Bielefeld
- Germany
| | - Gunnar Jeschke
- Laboratory of Physical Chemistry
- Department of Chemistry and Applied Biosciences
- ETH Zurich
- 8093 Zurich
- Switzerland
| | - Anton Savitsky
- Physics Department
- Technical University Dortmund
- Dortmund
- Germany
| | - Maxim Yulikov
- Laboratory of Physical Chemistry
- Department of Chemistry and Applied Biosciences
- ETH Zurich
- 8093 Zurich
- Switzerland
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33
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Boudalis AK, Rogez G, Turek P. Determination of the Distributions of the Spin-Hamiltonian Parameters in Spin Triangles: A Combined Magnetic Susceptometry and Electron Paramagnetic Resonance Spectroscopic Study of the Highly Symmetric [Cr3O(PhCOO)6(py)3](ClO4)·0.5py. Inorg Chem 2018; 57:13259-13269. [DOI: 10.1021/acs.inorgchem.8b01764] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [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)
- Athanassios K. Boudalis
- Institut de Chimie de Strasbourg (UMR 7177, CNRS-Unistra), Université de Strasbourg, 4 rue Blaise Pascal, CS 90032, F-67081 Strasbourg, France
| | - Guillaume Rogez
- Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg, CNRS, UMR 7504, F-67000 Strasbourg, France
| | - Philippe Turek
- Institut de Chimie de Strasbourg (UMR 7177, CNRS-Unistra), Université de Strasbourg, 4 rue Blaise Pascal, CS 90032, F-67081 Strasbourg, France
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34
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Yang Y, Yang F, Gong YJ, Bahrenberg T, Feintuch A, Su XC, Goldfarb D. High Sensitivity In-Cell EPR Distance Measurements on Proteins using an Optimized Gd(III) Spin Label. J Phys Chem Lett 2018; 9:6119-6123. [PMID: 30277780 DOI: 10.1021/acs.jpclett.8b02663] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Distance measurements by electron-electron double resonance (DEER) carried out on spin-labeled proteins delivered into cells provide new insights into the conformational states of proteins in their native environment. Such measurements depend on spin labels that exhibit high redox stability and high DEER sensitivity. Here we present a new Gd(III)-based spin label, BrPSPy-DO3A-Gd(III), which was derived from an earlier label, BrPSPy-DO3MA-Gd(III), by removing the methyl group from the methyl acetate pending arms. The small chemical modification led to a reduction in the zero-field splitting and to a significant increase in the phase memory time, which together culminated in a remarkable improvement of in-cell DEER sensitivity, while maintaining the high distance resolution. The excellent performance of BrPSPy-DO3A-Gd(III) in in-cell DEER measurements was demonstrated on doubly labeled ubiquitin and GB1 delivered into HeLa cells by electroporation.
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Affiliation(s)
- Yin Yang
- Department of Chemical and Biological Physics , Weizmann Institute of Science , Rehovot 76100 , Israel
| | - Feng Yang
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) , Nankai University , Tianjin 300071 , China
| | - Yan-Jun Gong
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) , Nankai University , Tianjin 300071 , China
| | - Thorsten Bahrenberg
- Department of Chemical and Biological Physics , Weizmann Institute of Science , Rehovot 76100 , Israel
| | - Akiva Feintuch
- Department of Chemical and Biological Physics , Weizmann Institute of Science , Rehovot 76100 , Israel
| | - Xun-Cheng Su
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) , Nankai University , Tianjin 300071 , China
| | - Daniella Goldfarb
- Department of Chemical and Biological Physics , Weizmann Institute of Science , Rehovot 76100 , Israel
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