1
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Giannoulis A, Butbul K, Carmieli R, Kim J, Montrazi ET, Singh K, Frydman L. Cryogenic and Dissolution DNP NMR on γ-Irradiated Organic Molecules. J Am Chem Soc 2024; 146:20758-20769. [PMID: 39029111 PMCID: PMC11295201 DOI: 10.1021/jacs.4c04041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 06/19/2024] [Accepted: 06/21/2024] [Indexed: 07/21/2024]
Abstract
Nuclear magnetic resonance (NMR) plays a central role in the elucidation of chemical structures but is often limited by low sensitivity. Dissolution dynamic nuclear polarization (dDNP) emerges as a transformative methodology for both solution-state NMR and metabolic NMR imaging, which could overcome this limitation. Typically, dDNP relies on combining a stable radical with the analyte within a uniform glass under cryogenic conditions. The electron polarization is then transferred through microwave irradiation to the nuclei. The present study explores the use of radicals introduced via γ-irradiation, as bearers of the electron spins that will enhance 1H or 13C nuclides. 1H solid-state NMR spectra of γ-irradiated powders at 1-5 K revealed, upon microwave irradiation, signal enhancements that, in general, were higher than those achieved through conventional glass-based DNP. Transfer of these samples to a solution-state NMR spectrometer via a rapid dissolution driven by a superheated water provided significant enhancements of solution-state 1H NMR signals. Enhancements of 13C signals in the γ-irradiated solids were more modest, as a combined consequence of a low radical concentration and of the dilute concentration of 13C in the natural abundant samples examined. Nevertheless, ca. 700-800-fold enhancements in 13C solution NMR spectra of certain sites recorded at 11.7 T could still be achieved. A total disappearance of the radicals upon performing a dDNP-like aqueous dissolution and a high stability of the samples were found. Overall, the study showcases the advantages and limitations of γ-irradiated radicals as candidates for advancing spectroscopic dDNP-enhanced NMR.
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Affiliation(s)
- Angeliki Giannoulis
- Department
of Chemical and Biological Physics, Weizmann
Institute of Science, 234 Herzl Street, Rehovot 7610001, Israel
| | - Korin Butbul
- Department
of Chemical and Biological Physics, Weizmann
Institute of Science, 234 Herzl Street, Rehovot 7610001, Israel
| | - Raanan Carmieli
- Department
of Chemical Research Support, Weizmann Institute
of Science, 234 Herzl
Street, Rehovot 7610001, Israel
| | - Jihyun Kim
- Department
of Chemical and Biological Physics, Weizmann
Institute of Science, 234 Herzl Street, Rehovot 7610001, Israel
- Department
of Chemistry Education, Kyungpook National
University, Daegu 41566, Republic of Korea
| | - Elton Tadeu Montrazi
- Department
of Chemical and Biological Physics, Weizmann
Institute of Science, 234 Herzl Street, Rehovot 7610001, Israel
| | - Kawarpal Singh
- Department
of Chemical and Biological Physics, Weizmann
Institute of Science, 234 Herzl Street, Rehovot 7610001, Israel
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Cambridge CB2 1EW, U.K.
| | - Lucio Frydman
- Department
of Chemical and Biological Physics, Weizmann
Institute of Science, 234 Herzl Street, Rehovot 7610001, Israel
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2
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Levien M, Yang L, van der Ham A, Reinhard M, John M, Purea A, Ganz J, Marquardsen T, Tkach I, Orlando T, Bennati M. Overhauser enhanced liquid state nuclear magnetic resonance spectroscopy in one and two dimensions. Nat Commun 2024; 15:5904. [PMID: 39003303 PMCID: PMC11246421 DOI: 10.1038/s41467-024-50265-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Accepted: 07/02/2024] [Indexed: 07/15/2024] Open
Abstract
Nuclear magnetic resonance (NMR) is fundamental in the natural sciences, from chemical analysis and structural biology, to medicine and physics. Despite its enormous achievements, one of its most severe limitations is the low sensitivity, which arises from the small population difference of nuclear spin states. Methods such as dissolution dynamic nuclear polarization and parahydrogen induced hyperpolarization can enhance the NMR signal by several orders of magnitude, however, their intrinsic limitations render multidimensional hyperpolarized liquid-state NMR a challenge. Here, we report an instrumental design for 9.4 Tesla liquid-state dynamic nuclear polarization that enabled enhanced high-resolution NMR spectra in one and two-dimensions for small molecules, including drugs and metabolites. Achieved enhancements of up to two orders of magnitude translate to signal acquisition gains up to a factor of 10,000. We show that hyperpolarization can be transferred between nuclei, allowing DNP-enhanced two-dimensional 13C-13C correlation experiments at 13C natural abundance. The enhanced sensitivity opens up perspectives for structural determination of natural products or characterization of drugs, available in small quantities. The results provide a starting point for a broader implementation of DNP in liquid-state NMR.
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Affiliation(s)
- Marcel Levien
- Electron-Spin Resonance Spectroscopy, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077, Göttingen, Germany
- Institute of Physical Chemistry, Department of Chemistry, Georg-August-University, Tammannstr. 6, 37077, Göttingen, Germany
- Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Luming Yang
- Electron-Spin Resonance Spectroscopy, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077, Göttingen, Germany
| | - Alex van der Ham
- Electron-Spin Resonance Spectroscopy, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077, Göttingen, Germany
| | - Maik Reinhard
- Electron-Spin Resonance Spectroscopy, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077, Göttingen, Germany
- Institute of Physical Chemistry, Department of Chemistry, Georg-August-University, Tammannstr. 6, 37077, Göttingen, Germany
| | - Michael John
- Institute of Organic and Biomolecular Chemistry, Department of Chemistry, Georg-August-University, Tammannstr. 2, 37077, Göttingen, Germany
| | - Armin Purea
- Bruker Biospin GmbH, Rudolf-Plank-Str. 23, 76275, Ettlingen, Germany
| | - Jürgen Ganz
- Bruker Biospin GmbH, Rudolf-Plank-Str. 23, 76275, Ettlingen, Germany
| | | | - Igor Tkach
- Electron-Spin Resonance Spectroscopy, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077, Göttingen, Germany
| | - Tomas Orlando
- Electron-Spin Resonance Spectroscopy, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077, Göttingen, Germany
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., 32310, Tallahassee, FL, USA
| | - Marina Bennati
- Electron-Spin Resonance Spectroscopy, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077, Göttingen, Germany.
- Institute of Physical Chemistry, Department of Chemistry, Georg-August-University, Tammannstr. 6, 37077, Göttingen, Germany.
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3
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Okuno Y, Clore GM. Extending the Experimentally Accessible Range of Spin Dipole-Dipole Spectral Densities for Protein-Cosolute Interactions by Temperature-Dependent Solvent Paramagnetic Relaxation Enhancement Measurements. J Phys Chem B 2023; 127:7887-7898. [PMID: 37681752 DOI: 10.1021/acs.jpcb.3c05301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/09/2023]
Abstract
Longitudinal (Γ1) and transverse (Γ2) solvent paramagnetic relaxation enhancement (sPRE) yields field-dependent information in the form of spectral densities that provides unique information related to cosolute-protein interactions and electrostatics. A typical protein sPRE data set can only sample a few points on the spectral density curve, J(ω), within a narrow frequency window (500 MHz to ∼1 GHz). However, complex interactions and dynamics of paramagnetic cosolutes around a protein make it difficult to directly interpret the few experimentally accessible points of J(ω). In this paper, we show that it is possible to significantly extend the experimentally accessible frequency range (corresponding to a range from ∼270 MHz to 1.8 GHz) by acquiring a series of sPRE experiments at different temperatures. This approach is based on the scaling property of J(ω) originally proposed by Melchior and Fries for small molecules. Here, we demonstrate that the same scaling property also holds for geometrically far more complex systems such as proteins. Using the extended spectral densities derived from the scaling property as the reference dataset, we demonstrate that our previous approach that makes use of a non-Lorentzian Ansatz spectral density function to fit only J(0) and one to two J(ω) points allows one to obtain accurate values for the concentration-normalized equilibrium average of the electron-proton interspin separation ⟨r-6⟩norm and the correlation time τC, which provide quantitative information on the energetics and timescale, respectively, of local cosolute-protein interactions. We also show that effective near-surface potentials, ϕENS, obtained from ⟨r-6⟩norm provide a reliable and quantitative measure of intermolecular interactions including electrostatics, while ϕENS values obtained from only Γ1 or Γ2 sPRE rates can have significant artifacts as a consequence of potential variations and changes in the diffusive properties of the cosolute around the protein surface. Finally, we discuss the experimental feasibility and limitations of extracting the high-frequency limit of J(ω) that is related to ⟨r-8⟩norm and report on the extremely local intermolecular potential.
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Affiliation(s)
- Yusuke Okuno
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, United States
| | - G Marius Clore
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, United States
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4
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Dai D, Denysenkov V, Bagryanskaya EG, Tormyshev VM, Prisner TF, Kuzhelev AA. 13C Hyperpolarization of Viscous Liquids by Transfer of Solid-Effect 1H Dynamic Nuclear Polarization at High Magnetic Field. J Phys Chem Lett 2023; 14:7059-7064. [PMID: 37526333 DOI: 10.1021/acs.jpclett.3c01732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/02/2023]
Abstract
Dynamic nuclear polarization (DNP) is routinely used as a method for increasing the sensitivity to nuclear magnetic resonance (NMR). Recently, high-field solid-effect DNP in viscous liquids on 1H nuclei was demonstrated using narrow-line polarizing agents. Here we expand the applicability of DNP in viscous media to 13C nuclei. To hyperpolarize 13C nuclei, we combined solid-effect 1H DNP with a subsequent transfer of the 1H polarization to 13C via insensitive nuclei enhanced by polarization transfer (INEPT). We demonstrate this approach using a triarylmethyl radical as a polarizing agent and glycerol-13C3 as an analyte. We achieved 13C enhancement factors of up to 45 at a magnetic field of 9.4 T and room temperature.
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Affiliation(s)
- Danhua Dai
- Goethe University Frankfurt am Main, Institute of Physical and Theoretical Chemistry and Center for Biomolecular Magnetic Resonance, Max von Laue Str. 7, Frankfurt am Main 60438, Germany
| | - Vasyl Denysenkov
- Goethe University Frankfurt am Main, Institute of Physical and Theoretical Chemistry and Center for Biomolecular Magnetic Resonance, Max von Laue Str. 7, Frankfurt am Main 60438, Germany
| | - Elena G Bagryanskaya
- N. N. Vorozhtsov Institute of Organic Chemistry, Siberian Branch of Russian Academy of Sciences (SB RAS), Acad. Lavrentiev Avenue 9, Novosibirsk 630090, Russia
| | - Victor M Tormyshev
- N. N. Vorozhtsov Institute of Organic Chemistry, Siberian Branch of Russian Academy of Sciences (SB RAS), Acad. Lavrentiev Avenue 9, Novosibirsk 630090, Russia
| | - Thomas F Prisner
- Goethe University Frankfurt am Main, Institute of Physical and Theoretical Chemistry and Center for Biomolecular Magnetic Resonance, Max von Laue Str. 7, Frankfurt am Main 60438, Germany
| | - Andrei A Kuzhelev
- Goethe University Frankfurt am Main, Institute of Physical and Theoretical Chemistry and Center for Biomolecular Magnetic Resonance, Max von Laue Str. 7, Frankfurt am Main 60438, Germany
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5
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Negroni M, Kurzbach D. Missing Pieces in Structure Puzzles: How Hyperpolarized NMR Spectroscopy Can Complement Structural Biology and Biochemistry. Chembiochem 2023; 24:e202200703. [PMID: 36624049 DOI: 10.1002/cbic.202200703] [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: 11/30/2022] [Revised: 01/08/2023] [Accepted: 01/09/2023] [Indexed: 01/11/2023]
Abstract
Structure determination lies at the heart of many biochemical research programs. However, the "giants": X-ray diffraction, electron microscopy, molecular dynamics simulations, and nuclear magnetic resonance, among others, leave quite a few dark spots on the structural pictures drawn of proteins, nucleic acids, membranes, and other biomacromolecules. For example, structural models under physiological conditions or of short-lived intermediates often remain out of reach of the established experimental methods. This account frames the possibility of including hyperpolarized, that is, dramatically signal-enhanced NMR in existing workflows to fill these spots with detailed depictions. We highlight how integrating methods based on dissolution dynamic nuclear polarization can provide valuable complementary information about formerly inaccessible conformational spaces for many systems. A particular focus will be on hyperpolarized buffers to facilitate the NMR structure determination of challenging systems.
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Affiliation(s)
- Mattia Negroni
- Faculty of Chemistry, Institute of Biological Chemistry, University of Vienna, Währinger Str. 38, 1090, Vienna, Austria
| | - Dennis Kurzbach
- Faculty of Chemistry, Institute of Biological Chemistry, University of Vienna, Währinger Str. 38, 1090, Vienna, Austria
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6
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Eills J, Budker D, Cavagnero S, Chekmenev EY, Elliott SJ, Jannin S, Lesage A, Matysik J, Meersmann T, Prisner T, Reimer JA, Yang H, Koptyug IV. Spin Hyperpolarization in Modern Magnetic Resonance. Chem Rev 2023; 123:1417-1551. [PMID: 36701528 PMCID: PMC9951229 DOI: 10.1021/acs.chemrev.2c00534] [Citation(s) in RCA: 62] [Impact Index Per Article: 62.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Magnetic resonance techniques are successfully utilized in a broad range of scientific disciplines and in various practical applications, with medical magnetic resonance imaging being the most widely known example. Currently, both fundamental and applied magnetic resonance are enjoying a major boost owing to the rapidly developing field of spin hyperpolarization. Hyperpolarization techniques are able to enhance signal intensities in magnetic resonance by several orders of magnitude, and thus to largely overcome its major disadvantage of relatively low sensitivity. This provides new impetus for existing applications of magnetic resonance and opens the gates to exciting new possibilities. In this review, we provide a unified picture of the many methods and techniques that fall under the umbrella term "hyperpolarization" but are currently seldom perceived as integral parts of the same field. Specifically, before delving into the individual techniques, we provide a detailed analysis of the underlying principles of spin hyperpolarization. We attempt to uncover and classify the origins of hyperpolarization, to establish its sources and the specific mechanisms that enable the flow of polarization from a source to the target spins. We then give a more detailed analysis of individual hyperpolarization techniques: the mechanisms by which they work, fundamental and technical requirements, characteristic applications, unresolved issues, and possible future directions. We are seeing a continuous growth of activity in the field of spin hyperpolarization, and we expect the field to flourish as new and improved hyperpolarization techniques are implemented. Some key areas for development are in prolonging polarization lifetimes, making hyperpolarization techniques more generally applicable to chemical/biological systems, reducing the technical and equipment requirements, and creating more efficient excitation and detection schemes. We hope this review will facilitate the sharing of knowledge between subfields within the broad topic of hyperpolarization, to help overcome existing challenges in magnetic resonance and enable novel applications.
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Affiliation(s)
- James Eills
- Institute
for Bioengineering of Catalonia, Barcelona
Institute of Science and Technology, 08028Barcelona, Spain,
| | - Dmitry Budker
- Johannes
Gutenberg-Universität Mainz, 55128Mainz, Germany,Helmholtz-Institut,
GSI Helmholtzzentrum für Schwerionenforschung, 55128Mainz, Germany,Department
of Physics, UC Berkeley, Berkeley, California94720, United States
| | - Silvia Cavagnero
- Department
of Chemistry, University of Wisconsin, Madison, Madison, Wisconsin53706, United States
| | - Eduard Y. Chekmenev
- Department
of Chemistry, Integrative Biosciences (IBio), Karmanos Cancer Institute
(KCI), Wayne State University, Detroit, Michigan48202, United States,Russian
Academy of Sciences, Moscow119991, Russia
| | - Stuart J. Elliott
- Molecular
Sciences Research Hub, Imperial College
London, LondonW12 0BZ, United Kingdom
| | - Sami Jannin
- Centre
de RMN à Hauts Champs de Lyon, Université
de Lyon, CNRS, ENS Lyon, Université Lyon 1, 69100Villeurbanne, France
| | - Anne Lesage
- Centre
de RMN à Hauts Champs de Lyon, Université
de Lyon, CNRS, ENS Lyon, Université Lyon 1, 69100Villeurbanne, France
| | - Jörg Matysik
- Institut
für Analytische Chemie, Universität
Leipzig, Linnéstr. 3, 04103Leipzig, Germany
| | - Thomas Meersmann
- Sir
Peter Mansfield Imaging Centre, University Park, School of Medicine, University of Nottingham, NottinghamNG7 2RD, United Kingdom
| | - Thomas Prisner
- Institute
of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic
Resonance, Goethe University Frankfurt, , 60438Frankfurt
am Main, Germany
| | - Jeffrey A. Reimer
- Department
of Chemical and Biomolecular Engineering, UC Berkeley, and Materials Science Division, Lawrence Berkeley National
Laboratory, Berkeley, California94720, United States
| | - Hanming Yang
- Department
of Chemistry, University of Wisconsin, Madison, Madison, Wisconsin53706, United States
| | - Igor V. Koptyug
- International Tomography Center, Siberian
Branch of the Russian Academy
of Sciences, 630090Novosibirsk, Russia,
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7
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Okuno Y, Schwieters CD, Yang Z, Clore GM. Theory and Applications of Nitroxide-based Paramagnetic Cosolutes for Probing Intermolecular and Electrostatic Interactions on Protein Surfaces. J Am Chem Soc 2022; 144:21371-21388. [DOI: 10.1021/jacs.2c10035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Yusuke Okuno
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, United States
| | - Charles D. Schwieters
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, United States
- Computational Biomolecular Magnetic Resonance Core, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, United States
| | - Zhilin Yang
- Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - G. Marius Clore
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, United States
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8
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Kircher R, Mross S, Hasse H, Münnemann K. Functionalized Controlled Porous Glasses for Producing Radical-Free Hyperpolarized Liquids by Overhauser DNP. Molecules 2022; 27:molecules27196402. [PMID: 36234939 PMCID: PMC9572983 DOI: 10.3390/molecules27196402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 09/13/2022] [Accepted: 09/25/2022] [Indexed: 11/26/2022] Open
Abstract
Overhauser dynamic nuclear polarization (ODNP) can be used as a tool for NMR signal enhancement and happens on very short time scales. Therefore, ODNP is well suited for the measurement of fast-flowing samples, even in compact magnets, which is beneficial for the real-time monitoring of chemical reactions or processes. ODNP requires the presence of unpaired electrons in the sample, which is usually accomplished by the addition of stable radicals. However, radicals affect the nuclear relaxation times and can hamper the NMR detection. This is circumvented by immobilizing radicals in a packed bed allowing for the measurement of radical-free samples when using ex situ DNP techniques (DNP build-up and NMR detection happen at different places) and flow-induced separation of the hyperpolarized liquid from the radicals. Therefore, the synthesis of robust and chemically inert immobilized radical matrices is mandatory. In the present work, this is accomplished by immobilizing the radical glycidyloxy-tetramethylpiperidinyloxyl with a polyethyleneimine (PEI) linker on the surface of controlled porous glasses (CPG). Both the porosity of the CPGs and also the size of the PEI-linker were varied, resulting in a set of distinct radical matrices for continuous-flow ODNP. The study shows that CPGs with PEI-linkers provide robust, inert and efficient ODNP matrices.
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9
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Rao Y, Venkatesh A, Moutzouri P, Emsley L. 1H Hyperpolarization of Solutions by Overhauser Dynamic Nuclear Polarization with 13C- 1H Polarization Transfer. J Phys Chem Lett 2022; 13:7749-7755. [PMID: 35969266 PMCID: PMC9421900 DOI: 10.1021/acs.jpclett.2c01956] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 08/09/2022] [Indexed: 06/15/2023]
Abstract
Dynamic nuclear polarization (DNP) is a method that can significantly increase the sensitivity of nuclear magnetic resonance. The only effective DNP mechanism for in situ hyperpolarization in solution is Overhauser DNP, which is inefficient for 1H at high magnetic fields. Here we demonstrate the possibility of generating significant 1H hyperpolarization in solution at room temperature. To counter the poor direct 1H Overhauser DNP, we implement steady-state 13C Overhauser DNP in solutions and then transfer the 13C hyperpolarization to 1H via a reverse insensitive nuclei enhanced by polarization transfer scheme. We demonstrate this approach using a 400 MHz gyrotron-equipped 3.2 mm magic angle spinning DNP system to obtain 1H DNP enhancement factors of 48, 8, and 6 for chloroform, tetrachloroethane, and phenylacetylene, respectively, at room temperature.
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10
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Epasto LM, Che K, Kozak F, Selimovic A, Kadeřávek P, Kurzbach D. Toward protein NMR at physiological concentrations by hyperpolarized water-Finding and mapping uncharted conformational spaces. SCIENCE ADVANCES 2022; 8:eabq5179. [PMID: 35930648 PMCID: PMC9355353 DOI: 10.1126/sciadv.abq5179] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Nuclear magnetic resonance (NMR) spectroscopy is a key method for determining the structural dynamics of proteins in their native solution state. However, the low sensitivity of NMR typically necessitates nonphysiologically high sample concentrations, which often limit the relevance of the recorded data. We show how to use hyperpolarized water by dissolution dynamic nuclear polarization (DDNP) to acquire protein spectra at concentrations of 1 μM within seconds and with a high signal-to-noise ratio. The importance of approaching physiological concentrations is demonstrated for the vital MYC-associated factor X, which we show to switch conformations when diluted. While in vitro conditions lead to a population of the well-documented dimer, concentrations lowered by more than two orders of magnitude entail dimer dissociation and formation of a globularly folded monomer. We identified this structure by integrating DDNP with computational techniques to overcome the often-encountered constraint of DDNP of limited structural information provided by the typically detected one-dimensional spectra.
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Affiliation(s)
- Ludovica M. Epasto
- University of Vienna, Faculty of Chemistry, Institute of Biological Chemistry, Währinger Str. 38, 1090 Vienna, Austria
| | - Kateryna Che
- University of Vienna, Faculty of Chemistry, Institute of Biological Chemistry, Währinger Str. 38, 1090 Vienna, Austria
| | - Fanny Kozak
- University of Vienna, Faculty of Chemistry, Institute of Biological Chemistry, Währinger Str. 38, 1090 Vienna, Austria
| | - Albina Selimovic
- University of Vienna, Faculty of Chemistry, Institute of Biological Chemistry, Währinger Str. 38, 1090 Vienna, Austria
| | - Pavel Kadeřávek
- Masaryk University, CEITEC, Kamenice 5, 625 00 Brno, Czech Republic
| | - Dennis Kurzbach
- University of Vienna, Faculty of Chemistry, Institute of Biological Chemistry, Währinger Str. 38, 1090 Vienna, Austria
- Corresponding author.
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11
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Hilty C, Kurzbach D, Frydman L. Hyperpolarized water as universal sensitivity booster in biomolecular NMR. Nat Protoc 2022; 17:1621-1657. [PMID: 35546640 DOI: 10.1038/s41596-022-00693-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 02/25/2022] [Indexed: 11/09/2022]
Abstract
NMR spectroscopy is the only method to access the structural dynamics of biomolecules at high (atomistic) resolution in their native solution state. However, this method's low sensitivity has two important consequences: (i) typically experiments have to be performed at high concentrations that increase sensitivity but are not physiological, and (ii) signals have to be accumulated over long periods, complicating the determination of interaction kinetics on the order of seconds and impeding studies of unstable systems. Both limitations are of equal, fundamental relevance: non-native conditions are of limited pharmacological relevance, and the function of proteins, enzymes and nucleic acids often relies on their interaction kinetics. To overcome these limitations, we have developed applications that involve 'hyperpolarized water' to boost signal intensities in NMR of proteins and nucleic acids. The technique includes four stages: (i) preparation of the biomolecule in partially deuterated buffers, (ii) preparation of 'hyperpolarized' water featuring enhanced 1H NMR signals via cryogenic dynamic nuclear polarization, (iii) sudden melting of the cryogenic pellet and dissolution of the protein or nucleic acid in the hyperpolarized water (enabling spontaneous exchanges of protons between water and target) and (iv) recording signal-amplified NMR spectra targeting either labile 1H or neighboring 15N/13C nuclei in the biomolecule. Water in the ensuing experiments is used as a universal 'hyperpolarization' agent, rendering the approach versatile and applicable to any biomolecule possessing labile hydrogens. Thus, questions can be addressed, ranging from protein and RNA folding problems to resolving structure-function relationships of intrinsically disordered proteins to investigating membrane interactions.
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Affiliation(s)
- Christian Hilty
- Chemistry Department, Texas A&M University, College Station, TX, USA.
| | - Dennis Kurzbach
- Faculty of Chemistry, Institute for Biological Chemistry, University of Vienna, Vienna, Austria.
| | - Lucio Frydman
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel.
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12
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Denysenkov V, Dai D, Prisner TF. A triple resonance (e, 1H, 13C) probehead for liquid-state DNP experiments at 9.4 Tesla. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2022; 337:107185. [PMID: 35276481 DOI: 10.1016/j.jmr.2022.107185] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/24/2022] [Accepted: 02/27/2022] [Indexed: 06/14/2023]
Abstract
In DNP experiments, NMR signal intensity is increased by transferring the much larger electron spin polarization to nuclear spins via microwave irradiation. Here we describe the design and performance of a probehead that makes it possible to perform Overhauser DNP experiments at 1H and 13C in liquid samples with a volume of up to 100 nl. We demonstrate on a 13C-labeled sodium pyruvate sample in water that proton decoupling under DNP conditions is possible with this new triple-resonance DNP probehead. In addition, the heat dissipation from the sample has been greatly improved with our new probe design. This makes it possible to keep liquid samples at a constant temperature under irradiation with a high-frequency 263 GHz microwave gyrotron with a few watts of output power. This improved performance opens up the possibility to disentangle the role of sample temperature and applied microwave power for DNP efficiency in liquids and to obtain a quantitative determination of EPR saturation by observing the suppression of paramagnetic shift as a function of microwave power.
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Affiliation(s)
- Vasyl Denysenkov
- Institute for Physical Chemistry, and Center of Biomolecular Magnetic Resonance, Goethe University Frankfurt, Max von Laue Str. 7, 60438 Frankfurt am Main, Germany
| | - Danhua Dai
- Institute for Physical Chemistry, and Center of Biomolecular Magnetic Resonance, Goethe University Frankfurt, Max von Laue Str. 7, 60438 Frankfurt am Main, Germany
| | - Thomas F Prisner
- Institute for Physical Chemistry, and Center of Biomolecular Magnetic Resonance, Goethe University Frankfurt, Max von Laue Str. 7, 60438 Frankfurt am Main, Germany.
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13
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Eills J, Hale W, Utz M. Synergies between Hyperpolarized NMR and Microfluidics: A Review. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2022; 128:44-69. [PMID: 35282869 DOI: 10.1016/j.pnmrs.2021.09.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 09/10/2021] [Accepted: 09/11/2021] [Indexed: 06/14/2023]
Abstract
Hyperpolarized nuclear magnetic resonance and lab-on-a-chip microfluidics are two dynamic, but until recently quite distinct, fields of research. Recent developments in both areas increased their synergistic overlap. By microfluidic integration, many complex experimental steps can be brought together onto a single platform. Microfluidic devices are therefore increasingly finding applications in medical diagnostics, forensic analysis, and biomedical research. In particular, they provide novel and powerful ways to culture cells, cell aggregates, and even functional models of entire organs. Nuclear magnetic resonance is a non-invasive, high-resolution spectroscopic technique which allows real-time process monitoring with chemical specificity. It is ideally suited for observing metabolic and other biological and chemical processes in microfluidic systems. However, its intrinsically low sensitivity has limited its application. Recent advances in nuclear hyperpolarization techniques may change this: under special circumstances, it is possible to enhance NMR signals by up to 5 orders of magnitude, which dramatically extends the utility of NMR in the context of microfluidic systems. Hyperpolarization requires complex chemical and/or physical manipulations, which in turn may benefit from microfluidic implementation. In fact, many hyperpolarization methodologies rely on processes that are more efficient at the micro-scale, such as molecular diffusion, penetration of electromagnetic radiation into a sample, or restricted molecular mobility on a surface. In this review we examine the confluence between the fields of hyperpolarization-enhanced NMR and microfluidics, and assess how these areas of research have mutually benefited one another, and will continue to do so.
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Affiliation(s)
- James Eills
- Institute for Physics, Johannes Gutenberg University, D-55090 Mainz, Germany; GSI Helmholtzzentrum für Schwerionenforschung GmbH, Helmholtz-Institut Mainz, 55128 Mainz, Germany.
| | - William Hale
- Department of Chemistry, University of Florida, 32611, USA
| | - Marcel Utz
- School of Chemistry, University of Southampton, SO17 1BJ, UK.
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14
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Biedenbänder T, Aladin V, Saeidpour S, Corzilius B. Dynamic Nuclear Polarization for Sensitivity Enhancement in Biomolecular Solid-State NMR. Chem Rev 2022; 122:9738-9794. [PMID: 35099939 DOI: 10.1021/acs.chemrev.1c00776] [Citation(s) in RCA: 47] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Solid-state NMR with magic-angle spinning (MAS) is an important method in structural biology. While NMR can provide invaluable information about local geometry on an atomic scale even for large biomolecular assemblies lacking long-range order, it is often limited by low sensitivity due to small nuclear spin polarization in thermal equilibrium. Dynamic nuclear polarization (DNP) has evolved during the last decades to become a powerful method capable of increasing this sensitivity by two to three orders of magnitude, thereby reducing the valuable experimental time from weeks or months to just hours or days; in many cases, this allows experiments that would be otherwise completely unfeasible. In this review, we give an overview of the developments that have opened the field for DNP-enhanced biomolecular solid-state NMR including state-of-the-art applications at fast MAS and high magnetic field. We present DNP mechanisms, polarizing agents, and sample constitution methods suitable for biomolecules. A wide field of biomolecular NMR applications is covered including membrane proteins, amyloid fibrils, large biomolecular assemblies, and biomaterials. Finally, we present perspectives and recent developments that may shape the field of biomolecular DNP in the future.
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Affiliation(s)
- Thomas Biedenbänder
- Institute of Chemistry, University of Rostock, Albert-Einstein-Straße 3a, 18059 Rostock, Germany.,Department Life, Light & Matter, University of Rostock, Albert-Einstein-Straße 25, 18059 Rostock, Germany
| | - Victoria Aladin
- Institute of Chemistry, University of Rostock, Albert-Einstein-Straße 3a, 18059 Rostock, Germany.,Department Life, Light & Matter, University of Rostock, Albert-Einstein-Straße 25, 18059 Rostock, Germany
| | - Siavash Saeidpour
- Institute of Chemistry, University of Rostock, Albert-Einstein-Straße 3a, 18059 Rostock, Germany.,Department Life, Light & Matter, University of Rostock, Albert-Einstein-Straße 25, 18059 Rostock, Germany
| | - Björn Corzilius
- Institute of Chemistry, University of Rostock, Albert-Einstein-Straße 3a, 18059 Rostock, Germany.,Department Life, Light & Matter, University of Rostock, Albert-Einstein-Straße 25, 18059 Rostock, Germany
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15
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Gizatullin B, Mattea C, Stapf S. Three mechanisms of room temperature dynamic nuclear polarization occur simultaneously in an ionic liquid. Phys Chem Chem Phys 2022; 24:27004-27008. [DOI: 10.1039/d2cp03437a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
For the first time, several mechanisms of dynamic nuclear polarization, namely Overhauser, solid effect and cross effect/thermal mixing, have been identified in an ionic liquid with a nitroxide radical at ambient temperatures.
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Affiliation(s)
- Bulat Gizatullin
- FG Technische Physik II/Polymerphysik, Technische Universität Ilmenau, D-98684 Ilmenau, Germany
| | - Carlos Mattea
- FG Technische Physik II/Polymerphysik, Technische Universität Ilmenau, D-98684 Ilmenau, Germany
| | - Siegfried Stapf
- FG Technische Physik II/Polymerphysik, Technische Universität Ilmenau, D-98684 Ilmenau, Germany
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16
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Dai D, Wang X, Liu Y, Yang XL, Glaubitz C, Denysenkov V, He X, Prisner T, Mao J. Room-temperature dynamic nuclear polarization enhanced NMR spectroscopy of small biological molecules in water. Nat Commun 2021; 12:6880. [PMID: 34824218 PMCID: PMC8616939 DOI: 10.1038/s41467-021-27067-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 11/01/2021] [Indexed: 11/15/2022] Open
Abstract
Nuclear magnetic resonance (NMR) spectroscopy is a powerful and popular technique for probing the molecular structures, dynamics and chemical properties. However the conventional NMR spectroscopy is bottlenecked by its low sensitivity. Dynamic nuclear polarization (DNP) boosts NMR sensitivity by orders of magnitude and resolves this limitation. In liquid-state this revolutionizing technique has been restricted to a few specific non-biological model molecules in organic solvents. Here we show that the carbon polarization in small biological molecules, including carbohydrates and amino acids, can be enhanced sizably by in situ Overhauser DNP (ODNP) in water at room temperature and at high magnetic field. An observed connection between ODNP 13C enhancement factor and paramagnetic 13C NMR shift has led to the exploration of biologically relevant heterocyclic compound indole. The QM/MM MD simulation underscores the dynamics of intermolecular hydrogen bonds as the driving force for the scalar ODNP in a long-living radical-substrate complex. Our work reconciles results obtained by DNP spectroscopy, paramagnetic NMR and computational chemistry and provides new mechanistic insights into the high-field scalar ODNP.
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Affiliation(s)
- Danhua Dai
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, 60438, Frankfurt am Main, Germany
- Center for Biomolecular Magnetic Resonance, Goethe University Frankfurt, 60438, Frankfurt am Main, Germany
| | - Xianwei Wang
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200062, China
- College of Science, Zhejiang University of Technology, Hangzhou, Zhejiang, 310023, China
| | - Yiwei Liu
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200062, China
| | - Xiao-Liang Yang
- Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, China
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, China
| | - Clemens Glaubitz
- Center for Biomolecular Magnetic Resonance, Goethe University Frankfurt, 60438, Frankfurt am Main, Germany
- Institute of Biophysical Chemistry, Goethe University Frankfurt, 60438, Frankfurt am Main, Germany
| | - Vasyl Denysenkov
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, 60438, Frankfurt am Main, Germany
- Center for Biomolecular Magnetic Resonance, Goethe University Frankfurt, 60438, Frankfurt am Main, Germany
| | - Xiao He
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200062, China.
- NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai, 200062, China.
| | - Thomas Prisner
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, 60438, Frankfurt am Main, Germany
- Center for Biomolecular Magnetic Resonance, Goethe University Frankfurt, 60438, Frankfurt am Main, Germany
| | - Jiafei Mao
- Center for Biomolecular Magnetic Resonance, Goethe University Frankfurt, 60438, Frankfurt am Main, Germany.
- Institute of Biophysical Chemistry, Goethe University Frankfurt, 60438, Frankfurt am Main, Germany.
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17
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Zhang Z, Jiang Y, Pi H, Chen H, Liu C, Feng J, Liu M. THz-enhanced dynamic nuclear polarized liquid spectrometer. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2021; 330:107044. [PMID: 34352701 DOI: 10.1016/j.jmr.2021.107044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 07/21/2021] [Accepted: 07/22/2021] [Indexed: 06/13/2023]
Abstract
Dynamic nuclear polarization (DNP) technology can be utilized to dramatically enhance NMR signal. In this paper, we report on the development of a self-constructed 5 T DNP spectrometer for liquid samples and the 13C DNP enhancement achieved with this spectrometer. The DNP spectrometer is comprised of a wide-bore superconducting magnet, a home-made console, a dual resonance probe and a self-built 140 GHz microwave source for the spectrometer. Specifically, a microwave source of traveling wave tube (TWT) amplifier has been developed, which can provide a maximum power output of 4.4 W and a wide frequency tuning range of 1 GHz. The excellent performance of our built liquid-state DNP spectrometer is verified by the observation of more than 100-fold DNP enhancement of the 13C NMR signal for liquid 13CCl4 sample. Our result shows the superiority of DNP technology in the liquid-state high-field NMR spectrometer.
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Affiliation(s)
- Zhekai Zhang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yi Jiang
- Institute of Applied Electronics of CAEP, Mianyang 621900, China
| | - Haiya Pi
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hongbin Chen
- Institute of Applied Electronics of CAEP, Mianyang 621900, China.
| | - Chaoyang Liu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China; Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China.
| | - Jiwen Feng
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China.
| | - Maili Liu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China; Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
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18
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Marko A, Sojka A, Laguta O, Neugebauer P. Simulation of nitrogen nuclear spin magnetization of liquid solved nitroxides. Phys Chem Chem Phys 2021; 23:17310-17322. [PMID: 34346404 PMCID: PMC8371994 DOI: 10.1039/d0cp06071b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 06/25/2021] [Indexed: 12/15/2022]
Abstract
Nitroxide radicals are widely used in electron paramagnetic resonance (EPR) applications. Nitroxides are stable organic radicals containing the N-O˙ group with hyperfine coupled unpaired electron and nitrogen nuclear spins. In the past, much attention was devoted to studying nitroxide EPR spectra and electron spin magnetization evolution under various experimental conditions. However, the dynamics of nitrogen nuclear spin has not been investigated in detail so far. In this work, we performed quantitative prediction and simulation of nitrogen nuclear spin magnetization evolution in several magnetic resonance experiments. Our research was focused on fast rotating nitroxide radicals in liquid solutions. We used a general approach allowing us to compute electron and nitrogen nuclear spin magnetization from the same time-dependent spin density matrix obtained by solving the Liouville/von Neumann equation. We investigated the nitrogen nuclear spin dynamics subjected to various radiofrequency magnetic fields. Furthermore, we predicted a large dynamic nuclear polarization of nitrogen upon nitroxide irradiation with microwaves and analyzed its effect on the nitroxide EPR saturation factor.
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Affiliation(s)
- Andriy Marko
- Central European Institute of Technology, Brno University of TechnologyPurkynova-Str. 12361200BrnoCzech Republic
| | - Antonin Sojka
- Central European Institute of Technology, Brno University of TechnologyPurkynova-Str. 12361200BrnoCzech Republic
| | - Oleksii Laguta
- Central European Institute of Technology, Brno University of TechnologyPurkynova-Str. 12361200BrnoCzech Republic
| | - Petr Neugebauer
- Central European Institute of Technology, Brno University of TechnologyPurkynova-Str. 12361200BrnoCzech Republic
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19
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Fast-field-cycling ultralow-field nuclear magnetic relaxation dispersion. Nat Commun 2021; 12:4041. [PMID: 34193862 PMCID: PMC8245537 DOI: 10.1038/s41467-021-24248-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 06/07/2021] [Indexed: 12/03/2022] Open
Abstract
Optically pumped magnetometers (OPMs) based on alkali-atom vapors are ultra-sensitive devices for dc and low-frequency ac magnetic measurements. Here, in combination with fast-field-cycling hardware and high-resolution spectroscopic detection, we demonstrate applicability of OPMs in quantifying nuclear magnetic relaxation phenomena. Relaxation rate dispersion across the nT to mT field range enables quantitative investigation of extremely slow molecular motion correlations in the liquid state, with time constants > 1 ms, and insight into the corresponding relaxation mechanisms. The 10-20 fT/\documentclass[12pt]{minimal}
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\begin{document}$$\sqrt{{\rm{H}}}{\rm{z}}$$\end{document}Hz sensitivity of an OPM between 10 Hz and 5.5 kHz 1H Larmor frequency suffices to detect magnetic resonance signals from ~ 0.1 mL liquid volumes imbibed in simple mesoporous materials, or inside metal tubing, following nuclear spin prepolarization adjacent to the OPM. High-resolution spectroscopic detection can resolve inter-nucleus spin-spin couplings, further widening the scope of application to chemical systems. Expected limits of the technique regarding measurement of relaxation rates above 100 s−1 are discussed. Nuclear spin polarization and relaxation can be studied using nuclear magnetic resonance (NMR). Here the authors demonstrate a combination of fast-field cycling and optical magnetometry techniques, to realize a NMR sensor that operates in the region of very low frequency and high relaxation rate.
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20
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Parigi G, Ravera E, Fragai M, Luchinat C. Unveiling protein dynamics in solution with field-cycling NMR relaxometry. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2021; 124-125:85-98. [PMID: 34479712 DOI: 10.1016/j.pnmrs.2021.05.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 05/04/2021] [Accepted: 05/04/2021] [Indexed: 06/13/2023]
Abstract
Field-cycling NMR relaxometry is a well-established technique that can give information on molecular structure and dynamics of biological systems. It provides the nuclear relaxation rates as a function of the applied magnetic field, starting from fields as low as ~ 10-4 T up to about 1-3 T. The profiles so collected, called nuclear magnetic relaxation dispersion (NMRD) profiles, can be extended to include the relaxation rates at the largest fields achievable with high resolution NMR spectrometers. By exploiting this wide range of frequencies, the NMRD profiles can provide information on motions occurring on time scales from 10-6 to 10-9 s. 1H NMRD measurements have proved very useful also for the characterization of paramagnetic proteins, because they can help characterise a number of parameters including the number, distance and residence time of water molecules coordinated to the paramagnetic center, the reorientation correlation times and the electron spin relaxation time, and the electronic structure at the metal site.
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Affiliation(s)
- Giacomo Parigi
- Magnetic Resonance Center (CERM) University of Florence, via Sacconi 6, Sesto Fiorentino, Italy; Department of Chemistry, "Ugo Schiff", University of Florence, via della Lastruccia 3, Sesto Fiorentino, Italy; Consorzio Interuniversitario Risonanze Magnetiche di Metalloproteine (CIRMMP), via Sacconi 6, Sesto Fiorentino, Italy.
| | - Enrico Ravera
- Magnetic Resonance Center (CERM) University of Florence, via Sacconi 6, Sesto Fiorentino, Italy; Department of Chemistry, "Ugo Schiff", University of Florence, via della Lastruccia 3, Sesto Fiorentino, Italy; Consorzio Interuniversitario Risonanze Magnetiche di Metalloproteine (CIRMMP), via Sacconi 6, Sesto Fiorentino, Italy
| | - Marco Fragai
- Magnetic Resonance Center (CERM) University of Florence, via Sacconi 6, Sesto Fiorentino, Italy; Department of Chemistry, "Ugo Schiff", University of Florence, via della Lastruccia 3, Sesto Fiorentino, Italy; Consorzio Interuniversitario Risonanze Magnetiche di Metalloproteine (CIRMMP), via Sacconi 6, Sesto Fiorentino, Italy
| | - Claudio Luchinat
- Magnetic Resonance Center (CERM) University of Florence, via Sacconi 6, Sesto Fiorentino, Italy; Department of Chemistry, "Ugo Schiff", University of Florence, via della Lastruccia 3, Sesto Fiorentino, Italy; Consorzio Interuniversitario Risonanze Magnetiche di Metalloproteine (CIRMMP), via Sacconi 6, Sesto Fiorentino, Italy
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21
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Okuno Y, Szabo A, Clore GM. Quantitative Interpretation of Solvent Paramagnetic Relaxation for Probing Protein-Cosolute Interactions. J Am Chem Soc 2020; 142:8281-8290. [PMID: 32286812 DOI: 10.1021/jacs.0c00747] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Protein-small cosolute molecule interactions are ubiquitous and known to modulate the solubility, stability, and function of many proteins. Characterization of such transient weak interactions at atomic resolution remains challenging. In this work, we develop a simple and practical NMR method for extracting both energetic and dynamic information on protein-cosolute interactions from solvent paramagnetic relaxation enhancement (sPRE) measurements. Our procedure is based on an approximate (non-Lorentzian) spectral density that behaves exactly at both high and low frequencies. This spectral density contains two parameters, one global related to the translational diffusion coefficient of the paramagnetic cosolute, and the other residue specific. These parameters can be readily determined from sPRE data, and then used to calculate analytically a concentration normalized equilibrium average of the interspin distance, ⟨r-6⟩norm, and an effective correlation time, τC, that provide measures of the energetics and dynamics of the interaction at atomic resolution. We compare our approach with existing ones, and demonstrate the utility of our method using experimental 1H longitudinal and transverse sPRE data recorded on the protein ubiquitin in the presence of two different nitroxide radical cosolutes, at multiple static magnetic fields. The approach for analyzing sPRE data outlined here provides a powerful tool for deepening our understanding of extremely weak protein-cosolute interactions.
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Affiliation(s)
- Yusuke Okuno
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, United States
| | - Attila Szabo
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, United States
| | - G Marius Clore
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, United States
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22
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Keller TJ, Laut AJ, Sirigiri J, Maly T. High-resolution Overhauser dynamic nuclear polarization enhanced proton NMR spectroscopy at low magnetic fields. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2020; 313:106719. [PMID: 32217425 PMCID: PMC7172445 DOI: 10.1016/j.jmr.2020.106719] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 03/13/2020] [Accepted: 03/15/2020] [Indexed: 05/11/2023]
Abstract
Dynamic nuclear polarization (DNP) has gained large interest due to its ability to increase signal intensities in nuclear magnetic resonance (NMR) experiments by several orders of magnitude. Currently, DNP is typically used to enhance high-field, solid-state NMR experiments. However, the method is also capable of dramatically increasing the observed signal intensities in solution-state NMR spectroscopy. In this work, we demonstrate the application of Overhauser dynamic nuclear polarization (ODNP) spectroscopy at an NMR frequency of 14.5 MHz (0.35 T) to observe DNP-enhanced high-resolution NMR spectra of small molecules in solutions. Using a compact hybrid magnet with integrated shim coils to improve the magnetic field homogeneity we are able to routinely obtain proton linewidths of less than 4 Hz and enhancement factors >30. The excellent field resolution allows us to perform chemical-shift resolved ODNP experiments on ethyl crotonate to observe proton J-coupling. Furthermore, recording high-resolution ODNP-enhanced NMR spectra of ethylene glycol allows us to characterize the microwave induced sample heating in-situ, by measuring the separation of the OH and CH2 proton peaks.
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Affiliation(s)
| | | | | | - Thorsten Maly
- Bridge12 Technologies, 37 Loring Drive, Framingham, MA 01702, USA
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23
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Levien M, Hiller M, Tkach I, Bennati M, Orlando T. Nitroxide Derivatives for Dynamic Nuclear Polarization in Liquids: The Role of Rotational Diffusion. J Phys Chem Lett 2020; 11:1629-1635. [PMID: 32003568 PMCID: PMC7307959 DOI: 10.1021/acs.jpclett.0c00270] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 01/31/2020] [Indexed: 06/07/2023]
Abstract
Polarization transfer efficiency in liquid-state dynamic nuclear polarization (DNP) depends on the interaction between polarizing agents (PAs) and target nuclei modulated by molecular motions. We show how translational and rotational diffusion differently affect the DNP efficiency. These contributions were disentangled by measuring 1H-DNP enhancements of toluene and chloroform doped with nitroxide derivatives at 0.34 T as a function of either the temperature or the size of the PA. The results were employed to analyze 13C-DNP data at higher fields, where the polarization transfer is also driven by the Fermi contact interaction. In this case, bulky nitroxide PAs perform better than the small TEMPONE radical due to structural fluctuations of the ring conformation. These findings will help in designing PAs with features specifically optimized for liquid-state DNP at various magnetic fields.
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Affiliation(s)
- M. Levien
- Research
Group EPR Spectroscopy, Max Planck Institute
for Biophysical Chemistry, Göttingen 37077, Germany
- Department
of Chemistry, Georg-August University, Göttingen 37077, Germany
| | - M. Hiller
- Research
Group EPR Spectroscopy, Max Planck Institute
for Biophysical Chemistry, Göttingen 37077, Germany
| | - I. Tkach
- Research
Group EPR Spectroscopy, Max Planck Institute
for Biophysical Chemistry, Göttingen 37077, Germany
| | - M. Bennati
- Research
Group EPR Spectroscopy, Max Planck Institute
for Biophysical Chemistry, Göttingen 37077, Germany
- Department
of Chemistry, Georg-August University, Göttingen 37077, Germany
| | - T. Orlando
- Research
Group EPR Spectroscopy, Max Planck Institute
for Biophysical Chemistry, Göttingen 37077, Germany
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24
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Abstract
Dynamic nuclear polarization (DNP) is one of the most prominent methods of sensitivity enhancement in nuclear magnetic resonance (NMR). Even though solid-state DNP under magic-angle spinning (MAS) has left the proof-of-concept phase and has become an important tool for structural investigations of biomolecules as well as materials, it is still far from mainstream applicability because of the potentially overwhelming combination of unique instrumentation, complex sample preparation, and a multitude of different mechanisms and methods available. In this review, I introduce the diverse field and history of DNP, combining aspects of NMR and electron paramagnetic resonance. I then explain the general concepts and detailed mechanisms relevant at high magnetic field, including solution-state methods based on Overhauser DNP but with a greater focus on the more established MAS DNP methods. Finally, I review practical considerations and fields of application and discuss future developments.
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Affiliation(s)
- Björn Corzilius
- Institute of Chemistry and Department of Life, Light and Matter, University of Rostock, 18059 Rostock, Germany;
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25
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Dubroca T, Wi S, van Tol J, Frydman L, Hill S. Large volume liquid state scalar Overhauser dynamic nuclear polarization at high magnetic field. Phys Chem Chem Phys 2019; 21:21200-21204. [PMID: 31310269 DOI: 10.1039/c9cp02997d] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Dynamic Nuclear Polarization (DNP) can increase the sensitivity of Nuclear Magnetic Resonance (NMR), but it is challenging in the liquid state at high magnetic fields. In this study we demonstrate significant enhancements of NMR signals (up to 70 on 13C) in the liquid state by scalar Overhauser DNP at 14.1 T, with high resolution (∼0.1 ppm) and relatively large sample volume (∼100 μL).
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26
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Orlando T, Dervişoğlu R, Levien M, Tkach I, Prisner TF, Andreas LB, Denysenkov VP, Bennati M. Dynamic Nuclear Polarization of 13
C Nuclei in the Liquid State over a 10 Tesla Field Range. Angew Chem Int Ed Engl 2018; 58:1402-1406. [DOI: 10.1002/anie.201811892] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Indexed: 12/16/2022]
Affiliation(s)
- Tomas Orlando
- Research Group of EPR Spectroscopy; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
| | - Rıza Dervişoğlu
- Department of NMR Based Structural Biology; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
| | - Marcel Levien
- Research Group of EPR Spectroscopy; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
- Department of Chemistry; Georg-August-University; Tammannstrasse 4 Göttingen Germany
| | - Igor Tkach
- Research Group of EPR Spectroscopy; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
| | - Thomas F. Prisner
- Institute of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic Resonance; Goethe University; Max-von-Laue-Strasse 7 Frankfurt am Main Germany
| | - Loren B. Andreas
- Department of NMR Based Structural Biology; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
| | - Vasyl P. Denysenkov
- Institute of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic Resonance; Goethe University; Max-von-Laue-Strasse 7 Frankfurt am Main Germany
| | - Marina Bennati
- Research Group of EPR Spectroscopy; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
- Department of Chemistry; Georg-August-University; Tammannstrasse 4 Göttingen Germany
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27
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Orlando T, Dervişoğlu R, Levien M, Tkach I, Prisner TF, Andreas LB, Denysenkov VP, Bennati M. Dynamic Nuclear Polarization of 13
C Nuclei in the Liquid State over a 10 Tesla Field Range. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201811892] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Tomas Orlando
- Research Group of EPR Spectroscopy; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
| | - Rıza Dervişoğlu
- Department of NMR Based Structural Biology; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
| | - Marcel Levien
- Research Group of EPR Spectroscopy; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
- Department of Chemistry; Georg-August-University; Tammannstrasse 4 Göttingen Germany
| | - Igor Tkach
- Research Group of EPR Spectroscopy; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
| | - Thomas F. Prisner
- Institute of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic Resonance; Goethe University; Max-von-Laue-Strasse 7 Frankfurt am Main Germany
| | - Loren B. Andreas
- Department of NMR Based Structural Biology; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
| | - Vasyl P. Denysenkov
- Institute of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic Resonance; Goethe University; Max-von-Laue-Strasse 7 Frankfurt am Main Germany
| | - Marina Bennati
- Research Group of EPR Spectroscopy; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
- Department of Chemistry; Georg-August-University; Tammannstrasse 4 Göttingen Germany
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28
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Parigi G, Ravera E, Bennati M, Luchinat C. Understanding Overhauser Dynamic Nuclear Polarisation through NMR relaxometry. Mol Phys 2018. [DOI: 10.1080/00268976.2018.1527409] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Giacomo Parigi
- Magnetic Resonance Center (CERM) and Interuniversity Consortium for Magnetic Resonance of Metallo Proteins (CIRMMP), Sesto Fiorentino, Italy
- Department of Chemistry “Ugo Schiff”, University of Florence, Sesto Fiorentino, Italy
| | - Enrico Ravera
- Magnetic Resonance Center (CERM) and Interuniversity Consortium for Magnetic Resonance of Metallo Proteins (CIRMMP), Sesto Fiorentino, Italy
- Department of Chemistry “Ugo Schiff”, University of Florence, Sesto Fiorentino, Italy
| | - Marina Bennati
- Electron-Spin Resonance Spectroscopy, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
- Department of Chemistry, Georg-Augusta-University, Göttingen, Germany
| | - Claudio Luchinat
- Magnetic Resonance Center (CERM) and Interuniversity Consortium for Magnetic Resonance of Metallo Proteins (CIRMMP), Sesto Fiorentino, Italy
- Department of Chemistry “Ugo Schiff”, University of Florence, Sesto Fiorentino, Italy
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29
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Yoon D, Dimitriadis AI, Soundararajan M, Caspers C, Genoud J, Alberti S, de Rijk E, Ansermet JP. High-Field Liquid-State Dynamic Nuclear Polarization in Microliter Samples. Anal Chem 2018; 90:5620-5626. [PMID: 29620353 DOI: 10.1021/acs.analchem.7b04700] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nuclear hyperpolarization in the liquid state by dynamic nuclear polarization (DNP) has been of great interest because of its potential use in NMR spectroscopy of small samples of biological and chemical compounds in aqueous media. Liquid state DNP generally requires microwave resonators in order to generate an alternating magnetic field strong enough to saturate electron spins in the solution. As a consequence, the sample size is limited to dimensions of the order of the wavelength, and this restricts the sample volume to less than 100 nL for DNP at 9 T (∼260 GHz). We show here a new approach that overcomes this sample size limitation. Large saturation of electron spins was obtained with a high-power (∼150 W) gyrotron without microwave resonators. Since high power microwaves can cause serious dielectric heating in polar solutions, we designed a planar probe which effectively alleviates dielectric heating. A thin liquid sample of 100 μm of thickness is placed on a block of high thermal conductivity aluminum nitride, with a gold coating that serves both as a ground plane and as a heat sink. A meander or a coil were used for NMR. We performed 1H DNP at 9.2 T (∼260 GHz) and at room temperature with 10 μL of water, a volume that is more than 100× larger than reported so far. The 1H NMR signal is enhanced by a factor of about -10 with 70 W of microwave power. We also demonstrated the liquid state of 31P DNP in fluorobenzene containing triphenylphosphine and obtained an enhancement of ∼200.
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Affiliation(s)
- Dongyoung Yoon
- Institute of Physics , École Polytechnique Fédérale de Lausanne , CH-1015 Lausanne , Switzerland
| | - Alexandros I Dimitriadis
- Institute of Physics , École Polytechnique Fédérale de Lausanne , CH-1015 Lausanne , Switzerland.,SWISSto12 SA, 1015 , Lausanne , Switzerland
| | - Murari Soundararajan
- Institute of Physics , École Polytechnique Fédérale de Lausanne , CH-1015 Lausanne , Switzerland
| | - Christian Caspers
- Institute of Physics , École Polytechnique Fédérale de Lausanne , CH-1015 Lausanne , Switzerland
| | - Jeremy Genoud
- Institute of Physics , École Polytechnique Fédérale de Lausanne , CH-1015 Lausanne , Switzerland.,Swiss Plasma Center , École Polytechnique Fédérale de Lausanne , CH-1015 Lausanne , Switzerland
| | - Stefano Alberti
- Institute of Physics , École Polytechnique Fédérale de Lausanne , CH-1015 Lausanne , Switzerland.,Swiss Plasma Center , École Polytechnique Fédérale de Lausanne , CH-1015 Lausanne , Switzerland
| | - Emile de Rijk
- Institute of Physics , École Polytechnique Fédérale de Lausanne , CH-1015 Lausanne , Switzerland.,SWISSto12 SA, 1015 , Lausanne , Switzerland
| | - Jean-Philippe Ansermet
- Institute of Physics , École Polytechnique Fédérale de Lausanne , CH-1015 Lausanne , Switzerland
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30
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Dubroca T, Smith AN, Pike KJ, Froud S, Wylde R, Trociewitz B, McKay J, Mentink-Vigier F, van Tol J, Wi S, Brey W, Long JR, Frydman L, Hill S. A quasi-optical and corrugated waveguide microwave transmission system for simultaneous dynamic nuclear polarization NMR on two separate 14.1 T spectrometers. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 289:35-44. [PMID: 29459343 PMCID: PMC5978701 DOI: 10.1016/j.jmr.2018.01.015] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 01/25/2018] [Accepted: 01/25/2018] [Indexed: 05/03/2023]
Abstract
Nuclear magnetic resonance (NMR) is an intrinsically insensitive technique, with Boltzmann distributions of nuclear spin states on the order of parts per million in conventional magnetic fields. To overcome this limitation, dynamic nuclear polarization (DNP) can be used to gain up to three orders of magnitude in signal enhancement, which can decrease experimental time by up to six orders of magnitude. In DNP experiments, nuclear spin polarization is enhanced by transferring the relatively larger electron polarization to NMR active nuclei via microwave irradiation. Here, we describe the design and performance of a quasi-optical system enabling the use of a single 395 GHz gyrotron microwave source to simultaneously perform DNP experiments on two different 14.1 T (1H 600 MHz) NMR spectrometers: one configured for magic angle spinning (MAS) solid state NMR; the other configured for solution state NMR experiments. In particular, we describe how the high power microwave beam is split, transmitted, and manipulated between the two spectrometers. A 13C enhancement of 128 is achieved via the cross effect for alanine, using the nitroxide biradical AMUPol, under MAS-DNP conditions at 110 K, while a 31P enhancement of 160 is achieved via the Overhauser effect for triphenylphosphine using the monoradical BDPA under solution NMR conditions at room temperature. The latter result is the first demonstration of Overhauser DNP in the solution state at a field of 14.1 T (1H 600 MHz). Moreover these results have been produced with large sample volumes (∼100 µL, i.e. 3 mm diameter NMR tubes).
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Affiliation(s)
- Thierry Dubroca
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, FL 32310, USA
| | - Adam N. Smith
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, FL 32310, USA
- Department of Chemistry, University of Florida, 214 Leigh Hall, Gainesville, FL 32611, USA
| | - Kevin J. Pike
- Thomas Keating Ltd., Station Mills, Daux Road, Billingshurst, West Sussex RH14 9SH, UK
| | - Stuart Froud
- Thomas Keating Ltd., Station Mills, Daux Road, Billingshurst, West Sussex RH14 9SH, UK
| | - Richard Wylde
- Thomas Keating Ltd., Station Mills, Daux Road, Billingshurst, West Sussex RH14 9SH, UK
| | - Bianca Trociewitz
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, FL 32310, USA
| | - Johannes McKay
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, FL 32310, USA
| | | | - Johan van Tol
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, FL 32310, USA
| | - Sungsool Wi
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, FL 32310, USA
| | - William Brey
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, FL 32310, USA
| | - Joanna R. Long
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, FL 32310, USA
- Department of Biochemistry and Molecular Biology and National High Magnetic Field Laboratory, PO Box 100245, Gainesville, FL 32610-0245, USA
| | - Lucio Frydman
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, FL 32310, USA
- Department of Chemical and Biological Physics, Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Stephen Hill
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, FL 32310, USA
- Department of Physics, Florida State University, Tallahassee, FL 32306, USA
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31
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Biller JR, Stupic KF, Moreland J. A table-top PXI based low-field spectrometer for solution dynamic nuclear polarization. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2018; 56:153-163. [PMID: 29049871 DOI: 10.1002/mrc.4672] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 09/29/2017] [Accepted: 10/04/2017] [Indexed: 06/07/2023]
Abstract
We present the development of a portable dynamic nuclear polarization (DNP) instrument based on the PCI eXtensions for Instrumentation platform. The main purpose of the instrument is for study of 1 H polarization enhancements in solution through the Overhauser mechanism at low magnetic fields. A DNP probe set was constructed for use at 6.7 mT, using a modified Alderman-Grant resonator at 241 MHz for saturation of the electron transition. The solenoid for detection of the enhanced 1 H signal at 288 kHz was constructed with Litz wire. The largest observed 1 H enhancements (ε) at 6.7 mT for 14 N-CTPO radical in air saturated aqueous solution was ε~65. A concentration dependence of the enhancement is observed, with maximum ε at 5.5 mM. A low resonator efficiency for saturation of the electron paramagnetic resonance transition results in a decrease in ε for the 10.3 mM sample. At high incident powers (42 W) and long pump times, capacitor heating effects can also decrease the enhancement. The core unit and program described here could be easily adopted for multi-frequency DNP work, depending on available main magnets and selection of the "plug and play" arbitrary waveform generator, digitizer, and radiofrequency synthesizer PCI eXtensions for Instrumentatione cards.
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Affiliation(s)
- Joshua R Biller
- Physical Measurement Laboratory, National Institute of Standards and Technology, Boulder, CO, USA
| | - Karl F Stupic
- Physical Measurement Laboratory, National Institute of Standards and Technology, Boulder, CO, USA
| | - J Moreland
- Physical Measurement Laboratory, National Institute of Standards and Technology, Boulder, CO, USA
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32
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Biller JR, Barnes R, Han S. Perspective of Overhauser dynamic nuclear polarization for the study of soft materials. Curr Opin Colloid Interface Sci 2018. [DOI: 10.1016/j.cocis.2018.02.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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33
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Neugebauer P, Bloos D, Marx R, Lutz P, Kern M, Aguilà D, Vaverka J, Laguta O, Dietrich C, Clérac R, van Slageren J. Ultra-broadband EPR spectroscopy in field and frequency domains. Phys Chem Chem Phys 2018; 20:15528-15534. [DOI: 10.1039/c7cp07443c] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Electron paramagnetic resonance (EPR) is a powerful technique to investigate the electronic and magnetic properties of a wide range of materials.
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34
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Ravera E, Parigi G, Luchinat C. Perspectives on paramagnetic NMR from a life sciences infrastructure. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2017; 282:154-169. [PMID: 28844254 DOI: 10.1016/j.jmr.2017.07.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 07/28/2017] [Accepted: 07/31/2017] [Indexed: 05/17/2023]
Abstract
The effects arising in NMR spectroscopy because of the presence of unpaired electrons, collectively referred to as "paramagnetic NMR" have attracted increasing attention over the last decades. From the standpoint of the structural and mechanistic biology, paramagnetic NMR provides long range restraints that can be used to assess the accuracy of crystal structures in solution and to improve them by simultaneous refinements through NMR and X-ray data. These restraints also provide information on structure rearrangements and conformational variability in biomolecular systems. Theoretical improvements in quantum chemistry calculations can nowadays allow for accurate calculations of the paramagnetic data from a molecular structural model, thus providing a tool to refine the metal coordination environment by matching the paramagnetic effects observed far away from the metal. Furthermore, the availability of an improved technology (higher fields and faster magic angle spinning) has promoted paramagnetic NMR applications in the fast-growing area of biomolecular solid-state NMR. Major improvements in dynamic nuclear polarization have been recently achieved, especially through the exploitation of the Overhauser effect occurring through the contact-driven relaxation mechanism: the very large enhancement of the 13C signal observed in a variety of liquid organic compounds at high fields is expected to open up new perspectives for applications of solution NMR.
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Affiliation(s)
- Enrico Ravera
- Magnetic Resonance Center (CERM) and Department of Chemistry "Ugo Schiff", University of Florence, via Sacconi 6, 50019 Sesto Fiorentino, Italy
| | - Giacomo Parigi
- Magnetic Resonance Center (CERM) and Department of Chemistry "Ugo Schiff", University of Florence, via Sacconi 6, 50019 Sesto Fiorentino, Italy
| | - Claudio Luchinat
- Magnetic Resonance Center (CERM) and Department of Chemistry "Ugo Schiff", University of Florence, via Sacconi 6, 50019 Sesto Fiorentino, Italy.
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35
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Meenakumari V, Utsumi H, Jawahar A, Milton Franklin Benial A. ESR line width and line shape dependence of Overhauser-enhanced magnetic resonance imaging. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2016; 54:874-879. [PMID: 27432403 DOI: 10.1002/mrc.4489] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 07/10/2016] [Accepted: 07/13/2016] [Indexed: 06/06/2023]
Abstract
Electron spin resonance and Overhauser-enhanced magnetic resonance imaging studies were carried out for various concentrations of 14 N-labeled 3-carbamoyl-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl in pure water. Overhauser-enhancement factor attains maxima in the range of 2.5-3 mm concentration. The leakage factor showed an asymptotic increase with increasing agent concentration. The coupling parameter showed the interaction between the electron and nuclear spins to be mainly dipolar in origin. The electron spin resonance parameters, such as the line width, line shape and g-factor, were determined. The line width analysis confirms that the line broadening is proportional to the agent concentration, and also the agent concentration is optimized in the range of 2.5-3 mm. The line shape analysis shows that the observed electron spin resonance line shape is a Voigt line shape, in which the Lorentzian component is dominant. The contribution of Lorentzian component was estimated using the winsim package. The Lorentzian component of the resonance line attains maxima in the range of 2.5-3 mm concentration. Therefore, this study reveals that the agent concentration, line width and Lorentzian component are the important factors in determining the Overhauser-enhancement factor. Hence, the agent concentration was optimized as 2.5-3 mm for in vivo/in vitro electron spin resonance imaging and Overhauser-enhanced magnetic resonance imaging phantom studies. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- V Meenakumari
- Department of Physics, NMSSVN College, Madurai, Tamil Nadu, India
| | - Hideo Utsumi
- Innovation Center for Medical Redox Navigation, Kyushu University, Fukuoka, Japan
| | - A Jawahar
- Department of Chemistry, NMSSVN College, Madurai, Tamil Nadu, India
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36
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Yoon D, Soundararajan M, Caspers C, Braunmueller F, Genoud J, Alberti S, Ansermet JP. 500-fold enhancement of in situ (13)C liquid state NMR using gyrotron-driven temperature-jump DNP. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 270:142-146. [PMID: 27490302 DOI: 10.1016/j.jmr.2016.07.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 07/22/2016] [Accepted: 07/25/2016] [Indexed: 06/06/2023]
Abstract
A 550-fold increase in the liquid state (13)C NMR signal of a 50μL sample was obtained by first hyperpolarizing the sample at 20K using a gyrotron (260GHz), then, switching its frequency in order to apply 100W for 1.5s so as to melt the sample, finally, turning off the gyrotron to acquire the (13)C NMR signal. The sample stays in its NMR resonator, so the sequence can be repeated with rapid cooling as the entire cryostat stays cold. DNP and thawing of the sample are performed only by the switchable and tunable gyrotron without external devices. Rapid transition from DNP to thawing in one second time scale was necessary especially in order to enhance liquid (1)H NMR signal.
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Affiliation(s)
- Dongyoung Yoon
- Institute of Physics, École Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland.
| | - Murari Soundararajan
- Institute of Physics, École Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland
| | - Christian Caspers
- Institute of Physics, École Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland
| | - Falk Braunmueller
- Swiss Plasma Center, École Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland
| | - Jérémy Genoud
- Swiss Plasma Center, École Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland
| | - Stefano Alberti
- Swiss Plasma Center, École Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland
| | - Jean-Philippe Ansermet
- Institute of Physics, École Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland
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37
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van Meerten SGJ, Tayler MCD, Kentgens APM, van Bentum PJM. Towards Overhauser DNP in supercritical CO(2). JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 267:30-6. [PMID: 27082277 DOI: 10.1016/j.jmr.2016.04.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 04/01/2016] [Accepted: 04/03/2016] [Indexed: 05/14/2023]
Abstract
Overhauser Dynamic Nuclear Polarization (ODNP) is a well known technique to improve NMR sensitivity in the liquid state, where the large polarization of an electron spin is transferred to a nucleus of interest by cross-relaxation. The efficiency of the Overhauser mechanism for dipolar interactions depends critically on fast local translational dynamics at the timescale of the inverse electron Larmor frequency. The maximum polarization enhancement that can be achieved for (1)H at high magnetic fields benefits from a low viscosity solvent. In this paper we investigate the option to use supercritical CO2 as a solvent for Overhauser DNP. We have investigated the diffusion constants and longitudinal nuclear relaxation rates of toluene in high pressure CO2. The change in (1)H T1 by addition of TEMPO radical was analyzed to determine the Overhauser cross-relaxation in such a mixture, and is compared with calculations based on the Force Free Hard Sphere (FFHS) model. By analyzing the relaxation data within this model we find translational correlation times in the range of 2-4ps, depending on temperature, pressure and toluene concentration. Such short correlation times may be instrumental for future Overhauser DNP applications at high magnetic fields, as are commonly used in NMR. Preliminary DNP experiments have been performed at 3.4T on high pressure superheated water and model systems such as toluene in high pressure CO2.
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Affiliation(s)
- S G J van Meerten
- Radboud University, Institute for Molecules and Materials, Heyendaalseweg 135, 6525AJ Nijmegen, The Netherlands
| | - M C D Tayler
- Radboud University, Institute for Molecules and Materials, Heyendaalseweg 135, 6525AJ Nijmegen, The Netherlands
| | - A P M Kentgens
- Radboud University, Institute for Molecules and Materials, Heyendaalseweg 135, 6525AJ Nijmegen, The Netherlands
| | - P J M van Bentum
- Radboud University, Institute for Molecules and Materials, Heyendaalseweg 135, 6525AJ Nijmegen, The Netherlands.
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38
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Ravera E, Luchinat C, Parigi G. Basic facts and perspectives of Overhauser DNP NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 264:78-87. [PMID: 26920833 DOI: 10.1016/j.jmr.2015.12.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 12/16/2015] [Accepted: 12/17/2015] [Indexed: 05/03/2023]
Abstract
After the first surprisingly large (1)H DNP enhancements of the water signal in aqueous solutions of nitroxide radicals observed at high magnetic fields, Overhauser DNP is gaining increasing attention for a number of applications now flourishing, showing the potentialities of this mechanism in solution and solid state NMR as well as in MRI. Unexpected Overhauser DNP enhancements in insulating solids were recently measured at 100K, with a magnitude which increases with the applied magnetic field. We recapitulate here the theoretical premises of Overhauser DNP in solution and analyze the effects of the various parameters on the efficacy of the mechanism, underlining the link between the DNP enhancements and the field dependent relaxation properties. Promisingly, more effective DNP enhancements are expected by exploiting the potentialities offered by (13)C detection and the use of supercritical fluids.
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Affiliation(s)
- Enrico Ravera
- Magnetic Resonance Center (CERM) and Department of Chemistry "Ugo Schiff", University of Florence, Italy
| | - Claudio Luchinat
- Magnetic Resonance Center (CERM) and Department of Chemistry "Ugo Schiff", University of Florence, Italy
| | - Giacomo Parigi
- Magnetic Resonance Center (CERM) and Department of Chemistry "Ugo Schiff", University of Florence, Italy.
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39
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Prisner T, Denysenkov V, Sezer D. Liquid state DNP at high magnetic fields: Instrumentation, experimental results and atomistic modelling by molecular dynamics simulations. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 264:68-77. [PMID: 26920832 DOI: 10.1016/j.jmr.2015.11.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 11/11/2015] [Accepted: 11/12/2015] [Indexed: 05/14/2023]
Abstract
Dynamic nuclear polarization (DNP) at high magnetic fields has recently become one of the major research areas in magnetic resonance spectroscopy and imaging. Whereas much work has been devoted to experiments where the polarization transfer from the electron spin to the nuclear spin is performed in the solid state, only a few examples exist of experiments where the polarization transfer is performed in the liquid state. Here we describe such experiments at a magnetic field of 9.2 T, corresponding to a nuclear Larmor frequency of 400 MHz for proton spins and an excitation frequency of 263 GHz for the electron spins. The technical requirements to perform such experiments are discussed in the context of the double resonance structures that we have implemented. The experimental steps that allowed access to the enhancement factors for proton spins of several organic solvents with nitroxide radicals as polarizing agents are described. A computational scheme for calculating the coupling factors from molecular dynamics (MD) simulations is outlined and used to highlight the limitations of the classical models based on translational and rotational motion that are typically employed to quantify the observed coupling factors. The ability of MD simulations to predict enhancements for a variety of radicals and solvent molecules at any magnetic field strength should prove useful in optimizing experimental conditions for DNP in the liquid state.
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Affiliation(s)
- Thomas Prisner
- Institute of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic Resonance, Goethe University Frankfurt, Germany.
| | - Vasyl Denysenkov
- Institute of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic Resonance, Goethe University Frankfurt, Germany
| | - Deniz Sezer
- Faculty of Engineering and Natural Sciences, Sabancı University, Orhanlı-Tuzla, 34956 Istanbul, Turkey.
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40
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van Bentum J, van Meerten B, Sharma M, Kentgens A. Perspectives on DNP-enhanced NMR spectroscopy in solutions. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 264:59-67. [PMID: 26920831 DOI: 10.1016/j.jmr.2016.01.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 01/12/2016] [Accepted: 01/13/2016] [Indexed: 05/03/2023]
Abstract
More than 60 years after the seminal work of Albert Overhauser on dynamic nuclear polarization by dynamic cross relaxation of coupled electron-nuclear spin systems, the quest for sensitivity enhancement in NMR spectroscopy is as pressing as ever. In this contribution we will review the status and perspectives for dynamic nuclear polarization in the liquid state. An appealing approach seems to be the use of supercritical solvents that may allow an extension of the Overhauser mechanism towards common high magnetic fields. A complementary approach is the use of solid state DNP on frozen solutions, followed by a rapid dissolution or in-situ melting step and NMR detection with substantially enhanced polarization levels in the liquid state. We will review recent developments in the field and discuss perspectives for the near future.
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41
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Yoon D, Soundararajan M, Cuanillon P, Braunmueller F, Alberti S, Ansermet JP. Dynamic nuclear polarization by frequency modulation of a tunable gyrotron of 260GHz. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 262:62-67. [PMID: 26759116 DOI: 10.1016/j.jmr.2015.11.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 11/20/2015] [Accepted: 11/21/2015] [Indexed: 06/05/2023]
Abstract
An increase in Dynamic Nuclear Polarization (DNP) signal intensity is obtained with a tunable gyrotron producing frequency modulation around 260GHz at power levels less than 1W. The sweep rate of frequency modulation can reach 14kHz, and its amplitude is fixed at 50MHz. In water/glycerol glassy ice doped with 40mM TEMPOL, the relative increase in the DNP enhancement was obtained as a function of frequency-sweep rate for several temperatures. A 68 % increase was obtained at 15K, thus giving a DNP enhancement of about 80. By employing λ/4 and λ/8 polarizer mirrors, we transformed the polarization of the microwave beam from linear to circular, and achieved an increase in the enhancement by a factor of about 66% for a given power.
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Affiliation(s)
- Dongyoung Yoon
- École Polytechnique Fédérale de Lausanne, Institute of Condensed Matter Physics, CH-1015 Lausanne-EPFL, Switzerland.
| | - Murari Soundararajan
- École Polytechnique Fédérale de Lausanne, Institute of Condensed Matter Physics, CH-1015 Lausanne-EPFL, Switzerland
| | - Philippe Cuanillon
- École Polytechnique Fédérale de Lausanne, Institute of Condensed Matter Physics, CH-1015 Lausanne-EPFL, Switzerland
| | - Falk Braunmueller
- Centre de Recherches en Physique des Plasmas, Station 13, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne-EPFL, CH-1015 Lausanne, Switzerland
| | - Stefano Alberti
- Centre de Recherches en Physique des Plasmas, Station 13, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne-EPFL, CH-1015 Lausanne, Switzerland
| | - Jean-Philippe Ansermet
- École Polytechnique Fédérale de Lausanne, Institute of Condensed Matter Physics, CH-1015 Lausanne-EPFL, Switzerland
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42
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Hoff DEM, Albert BJ, Saliba EP, Scott FJ, Choi EJ, Mardini M, Barnes AB. Frequency swept microwaves for hyperfine decoupling and time domain dynamic nuclear polarization. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2015; 72:79-89. [PMID: 26482131 PMCID: PMC4762658 DOI: 10.1016/j.ssnmr.2015.10.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2015] [Revised: 09/30/2015] [Accepted: 10/01/2015] [Indexed: 05/05/2023]
Abstract
Hyperfine decoupling and pulsed dynamic nuclear polarization (DNP) are promising techniques to improve high field DNP NMR. We explore experimental and theoretical considerations to implement them with magic angle spinning (MAS). Microwave field simulations using the high frequency structural simulator (HFSS) software suite are performed to characterize the inhomogeneous phase independent microwave field throughout a 198GHz MAS DNP probe. Our calculations show that a microwave power input of 17W is required to generate an average EPR nutation frequency of 0.84MHz. We also present a detailed calculation of microwave heating from the HFSS parameters and find that 7.1% of the incident microwave power contributes to dielectric sample heating. Voltage tunable gyrotron oscillators are proposed as a class of frequency agile microwave sources to generate microwave frequency sweeps required for the frequency modulated cross effect, electron spin inversions, and hyperfine decoupling. Electron spin inversions of stable organic radicals are simulated with SPINEVOLUTION using the inhomogeneous microwave fields calculated by HFSS. We calculate an electron spin inversion efficiency of 56% at a spinning frequency of 5kHz. Finally, we demonstrate gyrotron acceleration potentials required to generate swept microwave frequency profiles for the frequency modulated cross effect and electron spin inversions.
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Affiliation(s)
- Daniel E M Hoff
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
| | - Brice J Albert
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
| | - Edward P Saliba
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
| | - Faith J Scott
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
| | - Eric J Choi
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
| | - Michael Mardini
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
| | - Alexander B Barnes
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA.
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43
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Wang X, Isley Iii WC, Salido SI, Sun Z, Song L, Tsai KH, Cramer CJ, Dorn HC. Optimization and prediction of the electron-nuclear dipolar and scalar interaction in 1H and 13C liquid state dynamic nuclear polarization. Chem Sci 2015; 6:6482-6495. [PMID: 30090267 PMCID: PMC6054052 DOI: 10.1039/c5sc02499d] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 07/25/2015] [Indexed: 12/19/2022] Open
Abstract
During the last 10-15 years, dynamic nuclear polarization (DNP) has evolved as a powerful tool for hyperpolarization of NMR and MRI nuclides. However, it is not as well appreciated that solution-state dynamic nuclear polarization is a powerful approach to study intermolecular interactions in solution. For solutions and fluids, the 1H nuclide is usually dominated by an Overhauser dipolar enhancement and can be significantly increased by decreasing the correlation time (τc) of the substrate/nitroxide interaction by utilizing supercritical fluids (SF CO2). For molecules containing the ubiquitous 13C nuclide, the Overhauser enhancement is usually a profile of both scalar and dipolar interactions. For carbon atoms without an attached hydrogen, a dipolar enhancement usually dominates as we illustrate for sp2 hybridized carbons in the fullerenes, C60 and C70. However, the scalar interaction is dependent on a Fermi contact interaction which does not have the magnetic field dependence inherent in the dipolar interaction. For a comprehensive range of molecular systems we show that molecules that exhibit weakly acidic complexation interaction(s) with nitroxides provide corresponding large scalar enhancements. For the first time, we report that sp hybridized (H-C) alkyne systems, for example, the phenylacetylene-nitroxide system exhibit very large scalar dominated enhancements. Finally, we demonstrate for a wide range of molecular systems that the Fermi contact interaction can be computationally predicted via electron-nuclear hyperfine coupling and correlated with experimental 13C DNP enhancements.
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Affiliation(s)
- X Wang
- Department of Chemistry , Virginia Tech , Blacksburg , Virginia 24061 , USA .
| | - W C Isley Iii
- Department of Chemistry and Minnesota Supercomputing Institute , University of Minnesota , Minneapolis , Minnesota 55455-0431 , USA .
| | - S I Salido
- Department of Chemistry , Virginia Tech , Blacksburg , Virginia 24061 , USA .
| | - Z Sun
- Department of Chemistry , Virginia Tech , Blacksburg , Virginia 24061 , USA .
| | - L Song
- Department of Chemistry , Virginia Tech , Blacksburg , Virginia 24061 , USA .
| | - K H Tsai
- Department of Chemistry , Virginia Tech , Blacksburg , Virginia 24061 , USA .
| | - C J Cramer
- Department of Chemistry and Minnesota Supercomputing Institute , University of Minnesota , Minneapolis , Minnesota 55455-0431 , USA .
| | - H C Dorn
- Department of Chemistry , Virginia Tech , Blacksburg , Virginia 24061 , USA .
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44
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Küçük SE, Biktagirov T, Sezer D. Carbon and proton Overhauser DNP from MD simulations and ab initio calculations: TEMPOL in acetone. Phys Chem Chem Phys 2015; 17:24874-84. [PMID: 26343351 DOI: 10.1039/c5cp04405g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A computational analysis of the Overhauser effect is reported for the proton, methyl carbon, and carbonyl carbon nuclei of liquid acetone doped with the nitroxide radical TEMPOL. A practical methodology for calculating the dynamic nuclear polarization (DNP) coupling factors by accounting for both dipole-dipole and Fermi-contact interactions is presented. The contribution to the dipolar spectral density function of nuclear spins that are not too far from TEMPOL is computed through classical molecular dynamics (MD) simulations, whereas the contribution of distant spins is included analytically. Fermi contacts are obtained by subjecting a few molecules from every MD snapshot to ab initio quantum mechanical calculations. Scalar interaction is found to be an essential part of the (13)C Overhauser DNP. While mostly detrimental to the carbonyl carbon of acetone it is predicted to result in large enhancements of the methyl carbon signal at magnetic fields of 9 T and beyond. In contrast, scalar coupling is shown to be negligible for the protons of acetone. The additional influence of proton polarization on the carbon DNP (three-spin effect) is also analyzed computationally. Its effect, however, is concluded to be practically insignificant for liquid acetone.
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Affiliation(s)
- Sami Emre Küçük
- Faculty of Engineering and Natural Sciences, Sabanc University, Orhanl-Tuzla, 34956 Istanbul, Turkey.
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45
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Ardenkjaer-Larsen JH, Boebinger GS, Comment A, Duckett S, Edison AS, Engelke F, Griesinger C, Griffin RG, Hilty C, Maeda H, Parigi G, Prisner T, Ravera E, van Bentum J, Vega S, Webb A, Luchinat C, Schwalbe H, Frydman L. Facing and Overcoming Sensitivity Challenges in Biomolecular NMR Spectroscopy. Angew Chem Int Ed Engl 2015; 54:9162-85. [PMID: 26136394 PMCID: PMC4943876 DOI: 10.1002/anie.201410653] [Citation(s) in RCA: 217] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Revised: 01/26/2015] [Indexed: 11/07/2022]
Abstract
In the Spring of 2013, NMR spectroscopists convened at the Weizmann Institute in Israel to brainstorm on approaches to improve the sensitivity of NMR experiments, particularly when applied in biomolecular settings. This multi-author interdisciplinary Review presents a state-of-the-art description of the primary approaches that were considered. Topics discussed included the future of ultrahigh-field NMR systems, emerging NMR detection technologies, new approaches to nuclear hyperpolarization, and progress in sample preparation. All of these are orthogonal efforts, whose gains could multiply and thereby enhance the sensitivity of solid- and liquid-state experiments. While substantial advances have been made in all these areas, numerous challenges remain in the quest of endowing NMR spectroscopy with the sensitivity that has characterized forms of spectroscopies based on electrical or optical measurements. These challenges, and the ways by which scientists and engineers are striving to solve them, are also addressed.
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Affiliation(s)
- Jan-Henrik Ardenkjaer-Larsen
- GE Healthcare, Broendby, Denmark; Department of Electrical Engineering, Technical University of Denmark, Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital Hvidovre (Denmark)
| | - Gregory S Boebinger
- U.S. National High Magnetic Field Lab, Florida State University, Tallahassee, FL 32310 (USA)
| | - Arnaud Comment
- Institute of Physics of Biological Systems, Ecole Polytechnique Fédérale de Lausanne, Lausanne (Switzerland)
| | - Simon Duckett
- Department of Chemistry, University of York, Heslington, York, YO10 5DD (UK)
| | - Arthur S Edison
- Department of Biochemistry & Molecular Biology, University of Florida, Gainesville, FL 32610 (USA)
| | | | | | - Robert G Griffin
- Department of Chemistry and Francis Bitter Magnet Lab, MIT, Cambridge, MA 02139-4703 (USA)
| | - Christian Hilty
- Department of Chemistry, Texas A&M University, College Station (USA)
| | - Hidaeki Maeda
- Riken Center for Life Science Technologies, Yokohama, Kanagawa (Japan)
| | - Giacomo Parigi
- CERM and Department of Chemistry, University of Florence, Sesto Fiorentino (Italy)
| | - Thomas Prisner
- Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt, Max-von-Laue-Strasse 7, 60438 Frankfurt am Main (Germany)
| | - Enrico Ravera
- CERM and Department of Chemistry, University of Florence, Sesto Fiorentino (Italy)
| | | | - Shimon Vega
- Chemical Physics Department, Weizmann Institute of Science, Rehovot (Israel)
| | - Andrew Webb
- Department of Radiology, C. J. Gorter Center for High Field MRI, Leiden University Medical Center (The Netherlands)
| | - Claudio Luchinat
- CERM and Department of Chemistry, University of Florence, Sesto Fiorentino (Italy).
| | - Harald Schwalbe
- Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt, Max-von-Laue-Strasse 7, 60438 Frankfurt am Main (Germany).
| | - Lucio Frydman
- Chemical Physics Department, Weizmann Institute of Science, Rehovot (Israel).
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46
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Ardenkjaer-Larsen JH, Boebinger GS, Comment A, Duckett S, Edison AS, Engelke F, Griesinger C, Griffin RG, Hilty C, Maeda H, Parigi G, Prisner T, Ravera E, van Bentum J, Vega S, Webb A, Luchinat C, Schwalbe H, Frydman L. Neue Ansätze zur Empfindlichkeitssteigerung in der biomolekularen NMR-Spektroskopie. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201410653] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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47
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Küçük SE, Neugebauer P, Prisner TF, Sezer D. Molecular simulations for dynamic nuclear polarization in liquids: a case study of TEMPOL in acetone and DMSO. Phys Chem Chem Phys 2015; 17:6618-28. [PMID: 25665728 DOI: 10.1039/c4cp05832a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A computational strategy for calibrating, validating and analyzing molecular dynamics (MD) simulations to predict dynamic nuclear polarization (DNP) coupling factors and relaxivities of proton spins is presented. Simulations of the polarizing agent TEMPOL in liquid acetone and DMSO are conducted at low (infinite dilution) and high (1 M) concentrations of the free radical. Because DNP coupling factors and relaxivities are sensitive to the time scales of the molecular motions, the MD simulations are calibrated to reproduce the bulk translational diffusion coefficients of the pure solvents. The simulations are then validated by comparing with experimental dielectric relaxation spectra, which report on the rotational dynamics of the molecular electric dipole moments. The analysis consists of calculating spectral density functions (SDFs) of the magnetic dipole-dipole interaction between the electron spin of TEMPOL and nuclear spins of the solvent protons. Here, MD simulations are used in combination with an analytically tractable model of molecular motion. While the former provide detailed information at relatively short spin-spin distances, the latter includes contributions at large separations, all the way to infinity. The relaxivities calculated from the SDFs of acetone and DMSO are in excellent agreement with experiments at 9.2 T. For DMSO we calculate a coupling factor in agreement with experiment while for acetone we predict a value that is larger by almost 50%, suggesting a possibility for experimental improvement.
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Affiliation(s)
- Sami Emre Küçük
- Faculty of Engineering and Natural Sciences, Sabancı University, Orhanlı-Tuzla, 34956 Istanbul, Turkey.
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48
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Neugebauer P, Krummenacker JG, Denysenkov VP, Helmling C, Luchinat C, Parigi G, Prisner TF. High-field liquid state NMR hyperpolarization: a combined DNP/NMRD approach. Phys Chem Chem Phys 2015; 16:18781-7. [PMID: 25078259 DOI: 10.1039/c4cp02451f] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Here we show how fast dynamics between radicals and solvent molecules in liquid solutions can be detected by comparison of coupling factors determined by nuclear magnetic relaxation dispersion (NMRD) measurements and dynamic nuclear polarization (DNP) enhancement measurements at high magnetic field (9.2 T). This is important for a theoretical understanding of the Overhauser DNP mechanism at high magnetic fields and thus for optimization of the DNP agent/target system for high resolution liquid state NMR applications. Mixtures of the solution of TEMPOL radicals in water, toluene, acetone and DMSO have been investigated. The results are compared to the classical hard-sphere model and molecular dynamic simulations. Our results clearly indicate that fast sub-ps dynamics, which are not related to classical rotational or translational motion of the molecules, significantly contribute to the Overhauser DNP mechanism at high magnetic fields.
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Affiliation(s)
- Petr Neugebauer
- Institute of Physical and Theoretical Chemistry and Center for Biomolecular Magnetic Resonance (BMRZ), Goethe-University, Max-von-Laue-Str. 7, 60438, Frankfurt am Main, Germany.
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49
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Chappuis Q, Milani J, Vuichoud B, Bornet A, Gossert AD, Bodenhausen G, Jannin S. Hyperpolarized Water to Study Protein-Ligand Interactions. J Phys Chem Lett 2015; 6:1674-1678. [PMID: 26263332 DOI: 10.1021/acs.jpclett.5b00403] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The affinity between a chosen target protein and small molecules is a key aspect of drug discovery. Screening by popular NMR methods such as Water-LOGSY suffers from low sensitivity and from false positives caused by aggregated or denatured proteins. This work demonstrates that the sensitivity of Water-LOGSY can be greatly boosted by injecting hyperpolarized water into solutions of proteins and ligands. Ligand binding can be detected in a few seconds, whereas about 30 min is usually required without hyperpolarization. Hyperpolarized water also enhances proton signals of proteins at concentrations below 20 μM so that one can verify in a few seconds whether the proteins remain intact or have been denatured.
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Affiliation(s)
- Quentin Chappuis
- †Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Jonas Milani
- †Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Basile Vuichoud
- †Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Aurélien Bornet
- †Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Alvar D Gossert
- ‡Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Geoffrey Bodenhausen
- †Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
- §Département de Chimie, Ecole Normale Supérieure, PSL, 75005 Paris, France
- ⊥Sorbonne Université, UPMC Univ Paris 06, 75005 Paris, France
- #Laboratoire des BioMolécules, UMR 7203, 75005 Paris, France
| | - Sami Jannin
- †Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
- ∥Bruker BioSpin AG, 8117 Fällanden, Switzerland
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50
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Jakdetchai O, Denysenkov V, Becker-Baldus J, Dutagaci B, Prisner TF, Glaubitz C. Dynamic nuclear polarization-enhanced NMR on aligned lipid bilayers at ambient temperature. J Am Chem Soc 2014; 136:15533-6. [PMID: 25333422 DOI: 10.1021/ja509799s] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Dynamic nuclear polarization (DNP)-enhanced solid-state NMR spectroscopy has been shown to hold great potential for functional studies of membrane proteins at low temperatures due to its great sensitivity improvement. There are, however, numerous applications for which experiments at ambient temperature are desirable and which would also benefit from DNP signal enhancement. Here, we demonstrate as a proof of concept that a significant signal increase for lipid bilayers under room-temperature conditions can be achieved by utilizing the Overhauser effect. Experiments were carried out on aligned bilayers at 400 MHz/263 GHz using a stripline structure combined with a Fabry-Perot microwave resonator. A signal enhancement of protons of up to -10 was observed. Our results demonstrate that Overhauser DNP at high field provides efficient polarization transfer within insoluble samples, which is driven by fast local molecular fluctuations. Furthermore, our experimental setup offers an attractive option for DNP-enhanced solid-state NMR on ordered membranes and provides a general perspective toward DNP at ambient temperatures.
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Affiliation(s)
- Orawan Jakdetchai
- Institute of Biophysical Chemistry and ‡Institute of Physical and Theoretical Chemistry, Center for Biomolecular Magnetic Resonance Frankfurt, Goethe University Frankfurt , 60438 Frankfurt am Main, Germany
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