1
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Cheney DJ, Cerreia Vioglio P, Brookfield A, Blanc F. Optimisation of dynamic nuclear polarisation using "off-the-shelf" Gd(III)-based polarising agents. Phys Chem Chem Phys 2024; 26:24395-24406. [PMID: 39258402 DOI: 10.1039/d4cp02924k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/12/2024]
Abstract
Complexes of paramagnetic metal ions, in particular Gd3+, have been demonstrated as efficient polarising agents for magic-angle spinning (MAS) dynamic nuclear polarisation (DNP). We recently demonstrated that commercially available and inexpensive Gd(NO3)3 is suitable for use as an "off-the-shelf" MAS DNP polarising agent, providing promising sensitivity enhancements to 1H, 13C, and 15N NMR signals. Here we expand upon this approach by investigating the impact of the Gd(NO3)3 concentration and by exploring a larger range of readily available Gd3+ sources. We found that a Gd(NO3)3 concentration of 20 mM in the case of 1H and 13C, and 40 mM in the case of 15N, offers optimum signal enhancements and is rationalised as a trade-off between DNP enhancements, polarisation build-up times, and electron paramagnetic resonance (EPR) spin-spin relaxation times. We determined that a range of different gadolinium compounds (GdCl3, Gd2(SO4)3, GdBr3, and Gd(OAc)3) are also suitable for use as polarising agents and yield 1H, 13C, and 15N signal enhancements of variable values. Gd(OAc)3 yields lower signal enhancements, which is proposed to be the result of greater local asymmetry at the Gd3+ centre leading to EPR line broadening, and the methyl group in the acetate ion acting as a relaxation sink and limiting the nuclear polarisation available.
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Affiliation(s)
- Daniel J Cheney
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, UK.
| | - Paolo Cerreia Vioglio
- DNP MAS NMR Facility, Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham NG7 2RD, UK
| | - Adam Brookfield
- Department of Chemistry and Photon Science Institute, University of Manchester, Manchester M13 9PL, UK
| | - Frédéric Blanc
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, UK.
- Leverhulme Research Centre for Functional Materials Design, Materials Innovation Factory, University of Liverpool, Liverpool, L69 7ZD, UK
- Stephenson Institute for Renewable Energy, University of Liverpool, Liverpool L69 7ZF, UK
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2
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Menzildjian G, Schlagnitweit J, Casano G, Ouari O, Gajan D, Lesage A. Polarizing agents for efficient high field DNP solid-state NMR spectroscopy under magic-angle spinning: from design principles to formulation strategies. Chem Sci 2023; 14:6120-6148. [PMID: 37325158 PMCID: PMC10266460 DOI: 10.1039/d3sc01079a] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 05/09/2023] [Indexed: 06/17/2023] Open
Abstract
Dynamic Nuclear Polarization (DNP) has recently emerged as a cornerstone approach to enhance the sensitivity of solid-state NMR spectroscopy under Magic Angle Spinning (MAS), opening unprecedented analytical opportunities in chemistry and biology. DNP relies on a polarization transfer from unpaired electrons (present in endogenous or exogenous polarizing agents) to nearby nuclei. Developing and designing new polarizing sources for DNP solid-state NMR spectroscopy is currently an extremely active research field per se, that has recently led to significant breakthroughs and key achievements, in particular at high magnetic fields. This review describes recent developments in this area, highlighting key design principles that have been established over time and led to the introduction of increasingly more efficient polarizing sources. After a short introduction, Section 2 presents a brief history of solid-state DNP, highlighting the main polarization transfer schemes. The third section is devoted to the development of dinitroxide radicals, discussing the guidelines that were progressively established to design the fine-tuned molecular structures in use today. In Section 4, we describe recent efforts in developing hybrid radicals composed of a narrow EPR line radical covalently linked to a nitroxide, highlighting the parameters that modulate the DNP efficiency of these mixed structures. Section 5 reviews recent advances in the design of metal complexes suitable for DNP MAS NMR as exogenous electron sources. In parallel, current strategies that exploit metal ions as endogenous polarization sources are discussed. Section 6 briefly describes the recent introduction of mixed-valence radicals. In the last part, experimental aspects regarding sample formulation are reviewed to make best use of these polarizing agents in a broad panel of application fields.
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Affiliation(s)
- Georges Menzildjian
- Centre de RMN à, Très Hauts Champs, Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1) 5 Rue de la doua 69100 Villeurbanne France
| | - Judith Schlagnitweit
- Centre de RMN à, Très Hauts Champs, Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1) 5 Rue de la doua 69100 Villeurbanne France
| | - Gilles Casano
- Aix Marseille Univ., CNRS, Institut de Chimie Radicalaire, UMR 7273 Marseille France
| | - Olivier Ouari
- Aix Marseille Univ., CNRS, Institut de Chimie Radicalaire, UMR 7273 Marseille France
| | - David Gajan
- Centre de RMN à, Très Hauts Champs, Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1) 5 Rue de la doua 69100 Villeurbanne France
| | - Anne Lesage
- Centre de RMN à, Très Hauts Champs, Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1) 5 Rue de la doua 69100 Villeurbanne France
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3
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Thomas B, Jardón-Álvarez D, Carmieli R, van Tol J, Leskes M. The Effect of Disorder on Endogenous MAS-DNP: Study of Silicate Glasses and Crystals. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2023; 127:4759-4772. [PMID: 36925559 PMCID: PMC10009812 DOI: 10.1021/acs.jpcc.2c08849] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Revised: 02/05/2023] [Indexed: 06/18/2023]
Abstract
In dynamic nuclear polarization nuclear magnetic resonance (DNP-NMR) experiments, the large Boltzmann polarization of unpaired electrons is transferred to surrounding nuclei, leading to a significant increase in the sensitivity of the NMR signal. In order to obtain large polarization gains in the bulk of inorganic samples, paramagnetic metal ions are introduced as minor dopants acting as polarizing agents. While this approach has been shown to be very efficient in crystalline inorganic oxides, significantly lower enhancements have been reported when applying this approach to oxide glasses. In order to rationalize the origin of the difference in the efficiency of DNP in amorphous and crystalline inorganic matrices, we performed a detailed comparison in terms of their magnetic resonance properties. To diminish differences in the DNP performance arising from distinct nuclear interactions, glass and crystal systems of similar compositions were chosen, Li2OCaO·2SiO2 and Li2CaSiO4, respectively. Using Gd(III) as polarizing agent, DNP provided signal enhancements in the range of 100 for the crystalline sample, while only up to around factor 5 in the glass, for both 6Li and 29Si nuclei. We find that the drop in enhancement in glasses can be attributed to three main factors: shorter nuclear and electron relaxation times as well as the dielectric properties of glass and crystal. The amorphous nature of the glass sample is responsible for a high dielectric loss, leading to efficient microwave absorption and consequently lower effective microwave power and an increase in sample temperature which leads to further reduction of the electron relaxation time. These results help rationalize the observed sensitivity enhancements and provide guidance in identifying materials that could benefit from the DNP approach.
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Affiliation(s)
- Brijith Thomas
- Department
of Molecular Chemistry & Materials Science, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Daniel Jardón-Álvarez
- Department
of Molecular Chemistry & Materials Science, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Raanan Carmieli
- Department
of Chemical Research Support, Weizmann Institute
of Science, Rehovot 76100, Israel
| | - Johan van Tol
- National
High Magnetic Field Laboratory, Florida
State University, Tallahassee, Florida 32310, United States
| | - Michal Leskes
- Department
of Molecular Chemistry & Materials Science, Weizmann Institute of Science, Rehovot 76100, Israel
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4
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Buch CD, Kundu K, Marbey JJ, van Tol J, Weihe H, Hill S, Piligkos S. Spin–Lattice Relaxation Decoherence Suppression in Vanishing Orbital Angular Momentum Qubits. J Am Chem Soc 2022; 144:17597-17603. [DOI: 10.1021/jacs.2c07057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Christian D. Buch
- Department of Chemistry, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Krishnendu Kundu
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, United States
| | - Jonathan J. Marbey
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, United States
| | - Johan van Tol
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, United States
| | - Høgni Weihe
- Department of Chemistry, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Stephen Hill
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, United States
| | - Stergios Piligkos
- Department of Chemistry, University of Copenhagen, DK-2100 Copenhagen, Denmark
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5
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Elliott SJ, Duff BB, Taylor-Hughes AR, Cheney DJ, Corley JP, Paul S, Brookfield A, Pawsey S, Gajan D, Aspinall HC, Lesage A, Blanc F. Off-the-Shelf Gd(NO 3) 3 as an Efficient High-Spin Metal Ion Polarizing Agent for Magic Angle Spinning Dynamic Nuclear Polarization. J Phys Chem B 2022; 126:6281-6289. [PMID: 35973071 PMCID: PMC9421651 DOI: 10.1021/acs.jpcb.2c04184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Magic angle spinning nuclear magnetic resonance spectroscopy experiments are widely employed in the characterization of solid media. The approach is incredibly versatile but deleteriously suffers from low sensitivity, which may be alleviated by adopting dynamic nuclear polarization methods, resulting in large signal enhancements. Paramagnetic metal ions such as Gd3+ have recently shown promising results as polarizing agents for 1H, 13C, and 15N nuclear spins. We demonstrate that the widely available and inexpensive chemical agent Gd(NO3)3 achieves significant signal enhancements for the 13C and 15N nuclear sites of [2-13C,15N]glycine at 9.4 T and ∼105 K. Analysis of the signal enhancement profiles at two magnetic fields, in conjunction with electron paramagnetic resonance data, reveals the solid effect to be the dominant signal enhancement mechanism. The signal amplification obtained paves the way for efficient dynamic nuclear polarization without the need for challenging synthesis of Gd3+ polarizing agents.
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Affiliation(s)
- Stuart J Elliott
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, United Kingdom
| | - Benjamin B Duff
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, United Kingdom.,Stephenson Institute for Renewable Energy, University of Liverpool, Liverpool L69 7ZD, United Kingdom
| | | | - Daniel J Cheney
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, United Kingdom
| | - John P Corley
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, United Kingdom
| | - Subhradip Paul
- DNP MAS NMR Facility, Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham NG7 3RD, United Kingdom
| | - Adam Brookfield
- Department of Chemistry and Photon Science Institute, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Shane Pawsey
- Bruker BioSpin Corporation, Billerica, Massachusetts 01821, United States
| | - David Gajan
- Université de Lyon, Centre de Résonance Magnétique Nucléaire à Très Hauts Champs (UMR 5082, CNRS/ENS Lyon/UCBL), 69100 Villeurbanne, France
| | - Helen C Aspinall
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, United Kingdom
| | - Anne Lesage
- Université de Lyon, Centre de Résonance Magnétique Nucléaire à Très Hauts Champs (UMR 5082, CNRS/ENS Lyon/UCBL), 69100 Villeurbanne, France
| | - Frédéric Blanc
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, United Kingdom.,Stephenson Institute for Renewable Energy, University of Liverpool, Liverpool L69 7ZD, United Kingdom
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6
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Rao Y, Palumbo CT, Venkatesh A, Keener M, Stevanato G, Chauvin AS, Menzildjian G, Kuzin S, Yulikov M, Jeschke G, Lesage A, Mazzanti M, Emsley L. Design Principles for the Development of Gd(III) Polarizing Agents for Magic Angle Spinning Dynamic Nuclear Polarization. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2022; 126:11310-11317. [PMID: 35865791 PMCID: PMC9289950 DOI: 10.1021/acs.jpcc.2c01721] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Nuclear magnetic resonance suffers from an intrinsically low sensitivity, which can be overcome by dynamic nuclear polarization (DNP). Gd(III) complexes are attractive exogenous polarizing agents for magic angle spinning (MAS) DNP due to their high chemical stability in contrast to nitroxide-based radicals. However, even the state-of-the-art Gd(III) complexes have so far provided relatively low DNP signal enhancements of ca. 36 in comparison to standard DNP biradicals, which show enhancements of over 200. Here, we report a series of new Gd(III) complexes for DNP and show that the observed DNP enhancements of the new and existing Gd(III) complexes are inversely proportional to the square of the zero-field splitting (ZFS) parameter D, which is in turn determined by the ligand-type and the local coordination environment. The experimental DNP enhancements at 9.4 T and the ZFS parameters measured with pulsed electron paramagnetic resonance (EPR) spectroscopy agree with the above model, paving the way for the development of more efficient Gd(III) polarizing agents.
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Affiliation(s)
- Yu Rao
- Laboratory
of Magnetic Resonance, Institut des Sciences et Ingénierie
Chimiques, École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Chad T. Palumbo
- Group
of Coordination Chemistry, Institut des Sciences et Ingénierie
Chimiques, École Polytechnique Fédérale
de Lausanne (EPFL, CH-1015 Lausanne, Switzerland
| | - Amrit Venkatesh
- Laboratory
of Magnetic Resonance, Institut des Sciences et Ingénierie
Chimiques, École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Megan Keener
- Group
of Coordination Chemistry, Institut des Sciences et Ingénierie
Chimiques, École Polytechnique Fédérale
de Lausanne (EPFL, CH-1015 Lausanne, Switzerland
| | - Gabriele Stevanato
- Laboratory
of Magnetic Resonance, Institut des Sciences et Ingénierie
Chimiques, École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Anne-Sophie Chauvin
- Group
of Coordination Chemistry, Institut des Sciences et Ingénierie
Chimiques, École Polytechnique Fédérale
de Lausanne (EPFL, CH-1015 Lausanne, Switzerland
| | - Georges Menzildjian
- Laboratory
of Magnetic Resonance, Institut des Sciences et Ingénierie
Chimiques, École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Sergei Kuzin
- Laboratory
of Physical Chemistry, Department of Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Maxim Yulikov
- Laboratory
of Physical Chemistry, Department of Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Gunnar Jeschke
- Laboratory
of Physical Chemistry, Department of Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Anne Lesage
- Centre
de RMN à Très Hauts Champs, Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1), 69100 Villeurbanne, France
| | - Marinella Mazzanti
- Group
of Coordination Chemistry, Institut des Sciences et Ingénierie
Chimiques, École Polytechnique Fédérale
de Lausanne (EPFL, CH-1015 Lausanne, Switzerland
| | - Lyndon Emsley
- Laboratory
of Magnetic Resonance, Institut des Sciences et Ingénierie
Chimiques, École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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7
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Carnahan SL, Chen Y, Wishart JF, Lubach JW, Rossini AJ. Magic angle spinning dynamic nuclear polarization solid-state NMR spectroscopy of γ-irradiated molecular organic solids. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2022; 119:101785. [PMID: 35405629 DOI: 10.1016/j.ssnmr.2022.101785] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 02/22/2022] [Accepted: 03/04/2022] [Indexed: 06/14/2023]
Abstract
In the past 15 years, magic angle spinning (MAS) dynamic nuclear polarization (DNP) has emerged as a method to increase the sensitivity of high-resolution solid-state NMR spectroscopy experiments. Recently, γ-irradiation has been used to generate significant concentrations of homogeneously distributed free radicals in a variety of solids, including quartz, glucose, and cellulose. Both γ-irradiated quartz and glucose previously showed significant MAS DNP enhancements. Here, γ-irradiation is applied to twelve small organic molecules to test the applicability of γ-irradiation as a general method of creating stable free radicals for MAS DNP experiments on organic solids and pharmaceuticals. Radical concentrations in the range of 0.25 mM-10 mM were observed in irradiated glucose, histidine, malic acid, and malonic acid, and significant 1H DNP enhancements of 32, 130, 19, and 11 were obtained, respectively, as measured by 1H→13C CPMAS experiments. However, concentrations of free radicals below 0.05 mM were generally observed in organic molecules containing aromatic rings, preventing sizeable DNP enhancements. DNP sensitivity gains for several of the irradiated compounds exceed that which can be obtained with the relayed DNP approach that uses exogeneous polarizing agent solutions and impregnation procedures. In several cases, significant 1H DNP enhancements were realized at room temperature. This study demonstrates that in many cases γ-irradiation is a viable alternative to addition of stable exogenous radicals for DNP experiments on organic solids.
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Affiliation(s)
- Scott L Carnahan
- US DOE Ames Laboratory, Ames, IA, 50011, USA; Iowa State University, Department of Chemistry, Ames, IA, 50011, USA
| | - Yunhua Chen
- US DOE Ames Laboratory, Ames, IA, 50011, USA; Iowa State University, Department of Chemistry, Ames, IA, 50011, USA
| | - James F Wishart
- Brookhaven National Laboratory, Chemistry Division, Upton, NY, 11973, United States
| | - Joseph W Lubach
- Genentech Inc., South San Francisco, CA, 94080, United States
| | - Aaron J Rossini
- US DOE Ames Laboratory, Ames, IA, 50011, USA; Iowa State University, Department of Chemistry, Ames, IA, 50011, USA.
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8
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Chow WY, De Paëpe G, Hediger S. Biomolecular and Biological Applications of Solid-State NMR with Dynamic Nuclear Polarization Enhancement. Chem Rev 2022; 122:9795-9847. [PMID: 35446555 DOI: 10.1021/acs.chemrev.1c01043] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Solid-state NMR spectroscopy (ssNMR) with magic-angle spinning (MAS) enables the investigation of biological systems within their native context, such as lipid membranes, viral capsid assemblies, and cells. However, such ambitious investigations often suffer from low sensitivity due to the presence of significant amounts of other molecular species, which reduces the effective concentration of the biomolecule or interaction of interest. Certain investigations requiring the detection of very low concentration species remain unfeasible even with increasing experimental time for signal averaging. By applying dynamic nuclear polarization (DNP) to overcome the sensitivity challenge, the experimental time required can be reduced by orders of magnitude, broadening the feasible scope of applications for biological solid-state NMR. In this review, we outline strategies commonly adopted for biological applications of DNP, indicate ongoing challenges, and present a comprehensive overview of biological investigations where MAS-DNP has led to unique insights.
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Affiliation(s)
- Wing Ying Chow
- Univ. Grenoble Alpes, CEA, CNRS, Interdisciplinary Research Institute of Grenoble (IRIG), Modeling and Exploration of Materials Laboratory (MEM), 38054 Grenoble, France.,Univ. Grenoble Alpes, CEA, CNRS, Inst. Biol. Struct. IBS, 38044 Grenoble, France
| | - Gaël De Paëpe
- Univ. Grenoble Alpes, CEA, CNRS, Interdisciplinary Research Institute of Grenoble (IRIG), Modeling and Exploration of Materials Laboratory (MEM), 38054 Grenoble, France
| | - Sabine Hediger
- Univ. Grenoble Alpes, CEA, CNRS, Interdisciplinary Research Institute of Grenoble (IRIG), Modeling and Exploration of Materials Laboratory (MEM), 38054 Grenoble, France
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9
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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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10
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Mentink-Vigier F. Numerical recipes for faster MAS-DNP simulations. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2021; 333:107106. [PMID: 34837803 PMCID: PMC8639796 DOI: 10.1016/j.jmr.2021.107106] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 11/05/2021] [Accepted: 11/07/2021] [Indexed: 05/11/2023]
Abstract
Numerical simulations of Magic Angle Spinning Dynamic Nuclear Polarization (MAS-DNP) have transformed the way the DNP process is understood in rotating samples. In 2012, two methods were concomitantly developed to simulate small spin systems (< 4 spin-1/2). The development of new polarizing agents, including those containing metal centers with S > 1/2, makes it necessary to further expand the numerical tools with minimal approximations that will help rationalize the experimental observations and build approximate models. In this paper, three strategies developed in the past five years are presented: an adaptive integration scheme, a hybrid Hilbert/Liouville formalism, and a method to truncate the Liouville space basis for periodic Hamiltonian. Each of these methods enable time savings ranging from a factor of 3 to > 100. We illustrate the code performance by reporting for the first time the MAS-DNP field profiles for "AMUPol", in which the couplings to the nitrogen nuclei are explicitly considered, as well as Cross-Effect MAS-DNP field profiles with two electrons spin 5/2 interacting with a nuclear spin 1/2.
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Affiliation(s)
- Frederic Mentink-Vigier
- National High Magnetic Field Laboratory, Florida State University, 1800 E. Paul Dirac Dr, FL 32310, USA.
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11
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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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12
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Saliba EP, Barnes AB. Fast electron paramagnetic resonance magic angle spinning simulations using analytical powder averaging techniques. J Chem Phys 2019; 151:114107. [PMID: 31542017 PMCID: PMC7043854 DOI: 10.1063/1.5113598] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 08/27/2019] [Indexed: 11/14/2022] Open
Abstract
Simulations describing the spin physics underpinning nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) spectroscopy play an important role in the design of new experiments. When experiments are performed in the solid state, samples are commonly composed of powders or glasses, with molecules oriented at a large number of angles with respect to the laboratory frame. These powder angles must be represented in simulations to account for anisotropic interactions. Numerical techniques are typically used to accurately compute such powder averages. A large number of Euler angles are usually required, leading to lengthy simulation times. This is particularly true in broad spectra, such as those observed in EPR. The combination of the traditionally separate techniques of EPR and magic angle spinning (MAS) NMR could play an important role in future electron detected experiments, combined with dynamic nuclear polarization, which will allow for exceptional detection sensitivity of NMR spin coherences. Here, we present a method of reducing the required number of Euler angles in magnetic resonance simulations by analytically performing the powder average over one of the Euler angles in the static and MAS cases for the TEMPO nitroxide radical in a 7 T field. In the static case, this leads to a 97.5% reduction in simulation time over the fully numerical case and reproduces the expected spinning sideband manifold when simulated with a MAS frequency of 150 kHz. This technique is applicable to more traditional NMR experiments as well, such as those involving quadrupolar nuclei or multiple dimensions.
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Affiliation(s)
- Edward P Saliba
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, USA
| | - Alexander B Barnes
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, USA
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Wang X, Caulkins BG, Riviere G, Mueller LJ, Mentink-Vigier F, Long JR. Direct dynamic nuclear polarization of 15N and 13C spins at 14.1 T using a trityl radical and magic angle spinning. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2019; 100:85-91. [PMID: 31026722 PMCID: PMC6604067 DOI: 10.1016/j.ssnmr.2019.03.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 03/27/2019] [Accepted: 03/28/2019] [Indexed: 05/05/2023]
Abstract
We investigate solid-state dynamic nuclear polarization of 13C and 15N nuclei using monoradical trityl OX063 as a polarizing agent in a magnetic field of 14.1 T with magic angle spinning at ∼100 K. We monitored the field dependence of direct 13C and 15N polarization for frozen [13C, 15N] urea and achieved maximum absolute enhancement factors of 240 and 470, respectively. The field profiles are consistent with polarization of 15N spins via either the solid effect or the cross effect, and polarization of 13C spins via a combination of cross effect and solid effect. For microcrystalline, 15N-enriched tryptophan synthase sample containing trityl radical, a 1500-fold increase in 15N signal was observed under microwave irradiation. These results show the promise of trityl radicals and their derivatives for direct polarization of low gamma, spin-½ nuclei at high magnetic fields and suggest a novel approach for selectively polarizing specific moieties or for polarizing systems which have low levels of protonation.
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Affiliation(s)
- Xiaoling Wang
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, 32310, USA
| | - Bethany G Caulkins
- Department of Chemistry, University of California Riverside, Riverside, CA, 92521, USA
| | - Gwladys Riviere
- Department of Biochemistry and Molecular Biology, McKnight Brain Institute and National High Magnetic Field Laboratory, University of Florida, Gainesville, FL, 32610-0245, USA
| | - Leonard J Mueller
- Department of Chemistry, University of California Riverside, Riverside, CA, 92521, USA
| | - Frederic Mentink-Vigier
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, 32310, USA
| | - Joanna R Long
- Department of Biochemistry and Molecular Biology, McKnight Brain Institute and National High Magnetic Field Laboratory, University of Florida, Gainesville, FL, 32610-0245, USA.
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König A, Schölzel D, Uluca B, Viennet T, Akbey Ü, Heise H. Hyperpolarized MAS NMR of unfolded and misfolded proteins. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2019; 98:1-11. [PMID: 30641444 DOI: 10.1016/j.ssnmr.2018.12.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 12/28/2018] [Accepted: 12/30/2018] [Indexed: 05/09/2023]
Abstract
In this article we give an overview over the use of DNP-enhanced solid-state NMR spectroscopy for the investigation of unfolded, disordered and misfolded proteins. We first provide an overview over studies in which DNP spectroscopy has successfully been applied for the structural investigation of well-folded amyloid fibrils formed by short peptides as well as full-length proteins. Sample cooling to cryogenic temperatures often leads to severe line broadening of resonance signals and thus a loss in resolution. However, inhomogeneous line broadening at low temperatures provides valuable information about residual dynamics and flexibility in proteins, and, in combination with appropriate selective isotope labeling techniques, inhomogeneous linewidths in disordered proteins or protein regions may be exploited for evaluation of conformational ensembles. In the last paragraph we highlight some recent studies where DNP-enhanced MAS-NMR-spectroscopy was applied to the study of disordered proteins/protein regions and inhomogeneous sample preparations.
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Affiliation(s)
- Anna König
- Institute of Complex Systems, Structural Biochemistry (ICS-6), Research Center Jülich, 52425, Jülich, Germany; Institute of Physical Biology, Heinrich-Heine-University Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Daniel Schölzel
- Institute of Complex Systems, Structural Biochemistry (ICS-6), Research Center Jülich, 52425, Jülich, Germany; Institute of Physical Biology, Heinrich-Heine-University Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Boran Uluca
- Institute of Complex Systems, Structural Biochemistry (ICS-6), Research Center Jülich, 52425, Jülich, Germany; Institute of Physical Biology, Heinrich-Heine-University Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Thibault Viennet
- Institute of Complex Systems, Structural Biochemistry (ICS-6), Research Center Jülich, 52425, Jülich, Germany; Institute of Physical Biology, Heinrich-Heine-University Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Ümit Akbey
- Institute of Complex Systems, Structural Biochemistry (ICS-6), Research Center Jülich, 52425, Jülich, Germany; Institute of Physical Biology, Heinrich-Heine-University Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Henrike Heise
- Institute of Complex Systems, Structural Biochemistry (ICS-6), Research Center Jülich, 52425, Jülich, Germany; Institute of Physical Biology, Heinrich-Heine-University Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany.
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Lilly Thankamony AS, Wittmann JJ, Kaushik M, Corzilius B. Dynamic nuclear polarization for sensitivity enhancement in modern solid-state NMR. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2017; 102-103:120-195. [PMID: 29157490 DOI: 10.1016/j.pnmrs.2017.06.002] [Citation(s) in RCA: 278] [Impact Index Per Article: 39.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 06/03/2017] [Accepted: 06/08/2017] [Indexed: 05/03/2023]
Abstract
The field of dynamic nuclear polarization has undergone tremendous developments and diversification since its inception more than 6 decades ago. In this review we provide an in-depth overview of the relevant topics involved in DNP-enhanced MAS NMR spectroscopy. This includes the theoretical description of DNP mechanisms as well as of the polarization transfer pathways that can lead to a uniform or selective spreading of polarization between nuclear spins. Furthermore, we cover historical and state-of-the art aspects of dedicated instrumentation, polarizing agents, and optimization techniques for efficient MAS DNP. Finally, we present an extensive overview on applications in the fields of structural biology and materials science, which underlines that MAS DNP has moved far beyond the proof-of-concept stage and has become an important tool for research in these fields.
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Affiliation(s)
- Aany Sofia Lilly Thankamony
- Institute of Physical and Theoretical Chemistry, Institute of Biophysical Chemistry, and Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt, Max-von-Laue-Str. 7-9, 60438 Frankfurt, Germany
| | - Johannes J Wittmann
- Institute of Physical and Theoretical Chemistry, Institute of Biophysical Chemistry, and Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt, Max-von-Laue-Str. 7-9, 60438 Frankfurt, Germany
| | - Monu Kaushik
- Institute of Physical and Theoretical Chemistry, Institute of Biophysical Chemistry, and Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt, Max-von-Laue-Str. 7-9, 60438 Frankfurt, Germany
| | - Björn Corzilius
- Institute of Physical and Theoretical Chemistry, Institute of Biophysical Chemistry, and Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt, Max-von-Laue-Str. 7-9, 60438 Frankfurt, Germany.
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