1
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Chaklashiya RK, Equbal A, Shernyukov A, Li Y, Tsay K, Stern Q, Tormyshev V, Bagryanskaya E, Han S. Dynamic Nuclear Polarization Using Electron Spin Cluster. J Phys Chem Lett 2024; 15:5366-5375. [PMID: 38735065 DOI: 10.1021/acs.jpclett.4c00182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2024]
Abstract
Dynamic nuclear polarization (DNP) utilizing narrow-line electron spin clusters (ESCs) to achieve nuclear spin resonance matching (ESC-DNP) by microwave irradiation is a promising way to achieve NMR signal enhancements with a wide design scope requiring low microwave power at high magnetic field. Here we present the design for a trityl-based tetra-radical (TetraTrityl) to achieve DNP for 1H NMR at 7 T, supported by experimental data and quantum mechanical simulations. A slow-relaxing (T1e ≈ 1 ms) 4-ESC is found to require at least two electron spin pairs at <8 Å e-e spin distance to yield 1H ESC-DNP enhancement, while squeezing the rest of the e-e spin distances to <12 Å results in optimal 1H ESC-DNP enhancements. Fast-relaxing ESCs (T1e ≈ 10 μs) are found to require a weakly coupled narrow-line radical (sensitizer) to extract polarization from the ESC. These results provide design principles for achieving a power-efficient DNP at high field via ESC-DNP.
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Affiliation(s)
- Raj K Chaklashiya
- Materials Department, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Asif Equbal
- Division of Chemistry, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
- Center for Quantum and Topological Systems, NYUAD Research Institute, New York University Abu Dhabi, PO Box 129188, Abu Dhabi, United Arab Emirates
| | - Andrey Shernyukov
- N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, Novosibirsk 630090, Russia
| | - Yuanxin Li
- Department of Chemistry & Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Karen Tsay
- Department of Chemistry & Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Quentin Stern
- Department of Chemistry, Northwestern University, Wilmette, Illinois 60208, United States
| | - Victor Tormyshev
- N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, Novosibirsk 630090, Russia
| | - Elena Bagryanskaya
- N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, Novosibirsk 630090, Russia
| | - Songi Han
- Department of Chemistry, Northwestern University, Wilmette, Illinois 60208, United States
- Department of Chemical Engineering, University of California, Santa Barbara, Santa Barbara, California 93106, United States
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2
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Venkatesh A, Casano G, Wei R, Rao Y, Lingua H, Karoui H, Yulikov M, Ouari O, Emsley L. Rational Design of Dinitroxide Polarizing Agents for Dynamic Nuclear Polarization to Enhance Overall NMR Sensitivity. Angew Chem Int Ed Engl 2024; 63:e202317337. [PMID: 38193258 DOI: 10.1002/anie.202317337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 01/03/2024] [Accepted: 01/08/2024] [Indexed: 01/10/2024]
Abstract
We evaluate the overall sensitivity gains provided by a series of eighteen nitroxide biradicals for dynamic nuclear polarization (DNP) solid-state NMR at 9.4 T and 100 K, including eight new biradicals. We find that in the best performing group the factors contributing to the overall sensitivity gains, namely the DNP enhancement, the build-up time, and the contribution factor, often compete with each other leading to very similar overall sensitivity across a range of biradicals. NaphPol and HydroPol are found to provide the best overall sensitivity factors, in organic and aqueous solvents respectively. One of the new biradicals, AMUPolCbm, provides high sensitivity for all three solvent formulations measured here, and can be considered to be a "universal" polarizing agent.
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Affiliation(s)
- Amrit Venkatesh
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
- Current address: National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA
| | - Gilles Casano
- Aix Marseille Univ, CNRS, Institut de Chimie Radicalaire UMR 7273, 13013, Marseille, France
| | - Ran Wei
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Yu Rao
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Hugo Lingua
- Aix Marseille Univ, CNRS, Institut de Chimie Radicalaire UMR 7273, 13013, Marseille, France
| | - Hakim Karoui
- Aix Marseille Univ, CNRS, Institut de Chimie Radicalaire UMR 7273, 13013, Marseille, France
| | - Maxim Yulikov
- Laboratory of Physical Chemistry, Department of Chemistry, ETH Zürich, 8093, Zürich, Switzerland
| | - Olivier Ouari
- Aix Marseille Univ, CNRS, Institut de Chimie Radicalaire UMR 7273, 13013, Marseille, France
| | - Lyndon Emsley
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
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3
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Zhao Y, El Mkami H, Hunter RI, Casano G, Ouari O, Smith GM. Large cross-effect dynamic nuclear polarisation enhancements with kilowatt inverting chirped pulses at 94 GHz. Commun Chem 2023; 6:171. [PMID: 37607991 PMCID: PMC10444895 DOI: 10.1038/s42004-023-00963-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 07/25/2023] [Indexed: 08/24/2023] Open
Abstract
Dynamic nuclear polarisation (DNP) is a process that transfers electron spin polarisation to nuclei by applying resonant microwave radiation, and has been widely used to improve the sensitivity of nuclear magnetic resonance (NMR). Here we demonstrate new levels of performance for static cross-effect proton DNP using high peak power chirped inversion pulses at 94 GHz to create a strong polarisation gradient across the inhomogeneously broadened line of the mono-radical 4-amino TEMPO. Enhancements of up to 340 are achieved at an average power of a few hundred mW, with fast build-up times (3 s). Experiments are performed using a home-built wideband kW pulsed electron paramagnetic resonance (EPR) spectrometer operating at 94 GHz, integrated with an NMR detection system. Simultaneous DNP and EPR characterisation of other mono-radicals and biradicals, as a function of temperature, leads to additional insights into limiting relaxation mechanisms and give further motivation for the development of wideband pulsed amplifiers for DNP at higher frequencies.
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Affiliation(s)
- Yujie Zhao
- School of Physics and Astronomy, University of St Andrews, KY16 9SS, Fife, Scotland
| | - Hassane El Mkami
- School of Physics and Astronomy, University of St Andrews, KY16 9SS, Fife, Scotland
| | - Robert I Hunter
- School of Physics and Astronomy, University of St Andrews, KY16 9SS, Fife, Scotland
| | - Gilles Casano
- Aix Marseille University, CNRS, ICR, UMR 7273, F-13013, Marseille, France
| | - Olivier Ouari
- Aix Marseille University, CNRS, ICR, UMR 7273, F-13013, Marseille, France
| | - Graham M Smith
- School of Physics and Astronomy, University of St Andrews, KY16 9SS, Fife, Scotland.
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4
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Beatrez W, Pillai A, Janes O, Suter D, Ajoy A. Electron Induced Nanoscale Nuclear Spin Relaxation Probed by Hyperpolarization Injection. PHYSICAL REVIEW LETTERS 2023; 131:010802. [PMID: 37478433 DOI: 10.1103/physrevlett.131.010802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 06/07/2023] [Indexed: 07/23/2023]
Abstract
We report on experiments that quantify the role of a central electronic spin as a relaxation source for nuclear spins in its nanoscale environment. Our strategy exploits hyperpolarization injection from the electron as a means to controllably probe an increasing number of nuclear spins in the bath and subsequently interrogate them with high fidelity. Our experiments are focused on a model system of a nitrogen vacancy center electronic spin surrounded by several hundred ^{13}C nuclear spins. We observe that the ^{13}C transverse spin relaxation times vary significantly with the extent of hyperpolarization injection, allowing the ability to measure the influence of electron-mediated relaxation extending over several nanometers. These results suggest interesting new means to spatially discriminate nuclear spins in a nanoscale environment and have direct relevance to dynamic nuclear polarization and quantum sensors and memories constructed from hyperpolarized nuclei.
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Affiliation(s)
- William Beatrez
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, USA
| | - Arjun Pillai
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, USA
| | - Otto Janes
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, USA
| | - Dieter Suter
- Fakultät Physik, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - Ashok Ajoy
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, USA
- Lawrence Berkeley National Laboratory, Chemical Sciences Division, Berkeley, California 94720, USA
- CIFAR Azrieli Global Scholars Program, 661 University Ave, Toronto, ON M5G 1M1, Canada
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5
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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: 55] [Impact Index Per Article: 55.0] [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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6
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Jardón-Álvarez D, Malka T, van Tol J, Feldman Y, Carmieli R, Leskes M. Monitoring electron spin fluctuations with paramagnetic relaxation enhancement. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2022; 336:107143. [PMID: 35085928 DOI: 10.1016/j.jmr.2022.107143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 12/30/2021] [Accepted: 01/03/2022] [Indexed: 06/14/2023]
Abstract
The magnetic interactions between the spin of an unpaired electron and the surrounding nuclear spins can be exploited to gain structural information, to reduce nuclear relaxation times as well as to create nuclear hyperpolarization via dynamic nuclear polarization (DNP). A central aspect that determines how these interactions manifest from the point of view of NMR is the timescale of the fluctuations of the magnetic moment of the electron spins. These fluctuations, however, are elusive, particularly when electron relaxation times are short or interactions among electronic spins are strong. Here we map the fluctuations by analyzing the ratio between longitudinal and transverse nuclear relaxation times T1/T2, a quantity which depends uniquely on the rate of the electron fluctuations and the Larmor frequency of the involved nuclei. This analysis enables rationalizing the evolution of NMR lineshapes, signal quenching as well as DNP enhancements as a function of the concentration of the paramagnetic species and the temperature, demonstrated here for LiMg1-xMnxPO4 and Fe(III) doped Li4Ti5O12, respectively. For the latter, we observe a linear dependence of the DNP enhancement and the electron relaxation time within a temperature range between 100 and 300 K.
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Affiliation(s)
- Daniel Jardón-Álvarez
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Tahel Malka
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Johan van Tol
- National High Magnetic Field Laboratory, Florida State University, 1800 E. Paul Dirac Dr, Tallahassee, FL 32310, United States
| | - Yishay Feldman
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Raanan Carmieli
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Michal Leskes
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot 76100, Israel.
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7
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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: 42] [Impact Index Per Article: 21.0] [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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8
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Matsuki Y, Kobayashi T, Fukazawa J, Perras FA, Pruski M, Fujiwara T. Efficiency analysis of helium-cooled MAS DNP: case studies of surface-modified nanoparticles and homogeneous small-molecule solutions. Phys Chem Chem Phys 2021; 23:4919-4926. [PMID: 33620367 DOI: 10.1039/d0cp05658h] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Despite the growing number of successful applications of dynamic nuclear polarization (DNP)-enhanced magic-angle spinning (MAS) NMR in structural biology and materials science, the nuclear polarizations achieved by current MAS DNP instrumentation are still considerably lower than the theoretical maximum. The method could be significantly strengthened if experiments were performed at temperatures much lower than those currently widely used (∼100 K). Recently, the prospects of helium (He)-cooled MAS DNP have been increased with the instrumental developments in MAS technology that uses cold helium gas for sample cooling. Despite the additional gains in sensitivity that have been observed with He-cooled MAS DNP, the performance of the technique has not been evaluated in the case of surfaces and interfaces that benefit the most from DNP. Herein, we studied the efficiency of DNP at temperatures between ∼30 K and ∼100 K for organically functionalized silica material and a homogeneous solution of small organic molecules at a magnetic field B0 = 16.4 T. We recorded the changes in signal enhancement, paramagnet-induced quenching and depolarization effects, DNP build-up rate, and Boltzmann polarization. For these samples, the increases in MAS-induced depolarization and DNP build-up times at around 30 K were not as severe as anticipated. In the case of the surface species, we determined that MAS DNP at 30 K provided ∼10 times higher sensitivity than MAS DNP at 90 K, which corresponds to the acceleration of experiments by multiplicative factors of up to 100.
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Affiliation(s)
- Yoh Matsuki
- Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan and Center for Quantum Information and Quantum Biology, Institute for Open and Transdisciplinary Research Initiatives, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Takeshi Kobayashi
- Ames Laboratory, U.S. Department of Energy, Ames, Iowa 50011-3020, USA
| | - Jun Fukazawa
- Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan
| | - Frédéric A Perras
- Ames Laboratory, U.S. Department of Energy, Ames, Iowa 50011-3020, USA
| | - Marek Pruski
- Ames Laboratory, U.S. Department of Energy, Ames, Iowa 50011-3020, USA and Department of Chemistry, Iowa State University, Ames, Iowa 50011-3020, USA
| | - Toshimichi Fujiwara
- Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan and Center for Quantum Information and Quantum Biology, Institute for Open and Transdisciplinary Research Initiatives, Osaka University, Toyonaka, Osaka 560-0043, Japan
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9
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Prisco NA, Pinon AC, Emsley L, Chmelka BF. Scaling analyses for hyperpolarization transfer across a spin-diffusion barrier and into bulk solid media. Phys Chem Chem Phys 2021; 23:1006-1020. [PMID: 33404028 DOI: 10.1039/d0cp03195j] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
By analogy to heat and mass transfer film theory, a general approach is introduced for determining hyperpolarization transfer rates between dilute electron spins and a surrounding nuclear ensemble. These analyses provide new quantitative relationships for understanding, predicting, and optimizing the effectiveness of hyperpolarization protocols, such as Dynamic Nuclear Polarization (DNP) under magic-angle spinning conditions. An empirical DNP polarization-transfer coefficient is measured as a function of the bulk matrix 1H spin density and indicates the presence of two distinct kinetic regimes associated with different rate-limiting polarization transfer phenomena. Dimensional property relationships are derived and used to evaluate the competitive rates of spin polarization generation, propagation, and dissipation that govern hyperpolarization transfer between large coupled spin ensembles. The quantitative analyses agree closely with experimental measurements for the accumulation, propagation, and dissipation of hyperpolarization in solids and provide evidence for kinetically-limited transfer associated with a spin-diffusion barrier. The results and classical approach yield general design criteria for analyzing and optimizing polarization transfer processes involving complex interfaces and composite media for applications in materials science, physical chemistry and nuclear spintronics.
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Affiliation(s)
- Nathan A Prisco
- Department of Chemical Engineering, University of California Santa Barbara, USA.
| | - Arthur C Pinon
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland
| | - Lyndon Emsley
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland
| | - Bradley F Chmelka
- Department of Chemical Engineering, University of California Santa Barbara, USA.
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10
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Heiliger J, Matzel T, Çetiner EC, Schwalbe H, Kuenze G, Corzilius B. Site-specific dynamic nuclear polarization in a Gd(III)-labeled protein. Phys Chem Chem Phys 2020; 22:25455-25466. [PMID: 33103678 DOI: 10.1039/d0cp05021k] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Dynamic nuclear polarization (DNP) of a biomolecule tagged with a polarizing agent has the potential to not only increase NMR sensitivity but also to provide specificity towards the tagging site. Although the general concept has been often discussed, the observation of true site-specific DNP and its dependence on the electron-nuclear distance has been elusive. Here, we demonstrate site-specific DNP in a uniformly isotope-labeled ubiquitin. By recombinant expression of three different ubiquitin point mutants (F4C, A28C, and G75C) post-translationally modified with a Gd3+-chelator tag, localized metal-ion DNP of 13C and 15N is investigated. Effects counteracting the site-specificity of DNP such as nuclear spin-lattice relaxation and proton-driven spin diffusion have been attenuated by perdeuteration of the protein. Particularly for 15N, large DNP enhancement factors on the order of 100 and above as well as localized effects within side-chain resonances differently distributed over the protein are observed. By analyzing the experimental DNP built-up dynamics combined with structural modeling of Gd3+-tags in ubiquitin supported by paramagnetic relaxation enhancement (PRE) in solution, we provide, for the first time, quantitative information on the distance dependence of the initial DNP transfer. We show that the direct 15N DNP transfer rate indeed linearly depends on the square of the hyperfine interaction between the electron and the nucleus following Fermi's golden rule, however, below a certain distance cutoff paramagnetic signal bleaching may dramatically skew the correlation.
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Affiliation(s)
- Jörg Heiliger
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 7, 60438 Frankfurt am Main, Germany
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11
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Judge PT, Sesti EL, Price LE, Albert BJ, Alaniva N, Saliba EP, Halbritter T, Sigurdsson ST, Kyei GB, Barnes AB. Dynamic Nuclear Polarization with Electron Decoupling in Intact Human Cells and Cell Lysates. J Phys Chem B 2020; 124:2323-2330. [DOI: 10.1021/acs.jpcb.9b10494] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Patrick T. Judge
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
- Department of Biochemistry, Biophysics & Structural Biology, Washington University in St. Louis, St. Louis, Missouri 63110, United States
| | - Erika L. Sesti
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Lauren E. Price
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Brice J. Albert
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Nicholas Alaniva
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Edward P. Saliba
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Thomas Halbritter
- Department of Chemistry, Science Institute, University of Iceland, Dunhaga 3, 107 Reykjavik, Iceland
| | - Snorri Th. Sigurdsson
- Department of Chemistry, Science Institute, University of Iceland, Dunhaga 3, 107 Reykjavik, Iceland
| | - George B. Kyei
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63130, United States
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana,
Legon, Accra 02233, Ghana
| | - Alexander B. Barnes
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
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12
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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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13
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Daube D, Vogel M, Suess B, Corzilius B. Dynamic nuclear polarization on a hybridized hammerhead ribozyme: An explorative study of RNA folding and direct DNP with a paramagnetic metal ion cofactor. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2019; 101:21-30. [PMID: 31078101 DOI: 10.1016/j.ssnmr.2019.04.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 04/16/2019] [Accepted: 04/16/2019] [Indexed: 06/09/2023]
Abstract
While uniform isotope labeling of ribonucleic acids (RNA) can simply and efficiently be achieved by in-vitro transcription, the specific introduction of nucleotides in larger constructs is non-trivial and often ineffective. Here, we demonstrate how a medium-sized (67-mer), biocatalytically relevant RNA (hammerhead ribozyme, HHRz) can be formed by spontaneous hybridization of two differently isotope-labeled strands, each individually synthesized by in-vitro transcription. This allows on the one hand for a significant reduction in the number of isotope-labeled nucleotides and thus spectral overlap particularly under magic-angle spinning (MAS) dynamic nuclear polarization (DNP) NMR conditions, on the other hand for orthogonal 13C/15N-labeling of complementary strands and thus for specific investigation of structurally or functionally relevant inter-strand and/or inter-stem contacts. By this method, we are able to confirm a non-canonical interaction due to single-site resolution and unique spectral assignments by two-dimensional 13C-13C (PDSD) as well as 15N-13C (TEDOR) correlation spectroscopy under "conventional" DNP enhancement. This contact is indicative of the ribozyme's functional conformation, and is present in frozen solution irrespective of the presence or absence of a Mg2+ co-factor. Finally, we use different isotope-labeling schemes in order to investigate the distance dependence of paramagnetic interactions and direct metal-ion DNP if the diamagnetic Mg2+ is substituted by paramagnetic Mn2+.
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Affiliation(s)
- Diane Daube
- 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 am Main, Germany
| | - Marc Vogel
- Fachbereich Biologie, Technische Universität Darmstadt, Schnittspahnstraße 10, 64287 Darmstadt, Germany
| | - Beatrix Suess
- Fachbereich Biologie, Technische Universität Darmstadt, Schnittspahnstraße 10, 64287 Darmstadt, 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 am Main, Germany; Institut für Chemie, Universität Rostock, Albert-Einstein-Str. 3a, 18059 Rostock, Germany; Department LL&M, Universität Rostock, Albert-Einstein-Str. 25, 18059 Rostock, Germany.
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14
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Good DB, Voinov MA, Bolton D, Ward ME, Sergeyev IV, Caporini M, Scheffer P, Lo A, Rosay M, Marek A, Brown LS, I Smirnov A, Ladizhansky V. A biradical-tagged phospholipid as a polarizing agent for solid-state MAS Dynamic Nuclear Polarization NMR of membrane proteins. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2019; 100:92-101. [PMID: 31029957 PMCID: PMC6709687 DOI: 10.1016/j.ssnmr.2019.04.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 03/29/2019] [Accepted: 04/12/2019] [Indexed: 06/01/2023]
Abstract
A novel Dynamic Nuclear Polarization (DNP) NMR polarizing agent ToSMTSL-PTE representing a phospholipid with a biradical TOTAPOL tethered to the polar head group has been synthesized, characterized, and employed to enhance solid-state Nuclear Magnetic Resonance (SSNMR) signal of a lipid-reconstituted integral membrane protein proteorhodopsin (PR). A matrix-free PR formulation for DNP improved the absolute sensitivity of NMR signal by a factor of ca. 4 compared to a conventional preparation with TOTAPOL dispersed in a glassy glycerol/water matrix. DNP enhancements measured at 400 MHz/263 GHz and 600 MHz/395 GHz showed a strong field dependence but remained moderate at both fields, and comparable to those obtained for PR covalently modified with ToSMTSL. Additional continuous wave (CW) X-band electron paramagnetic resonance (EPR) experiments with ToSMTSL-PTE in solutions and in lipid bilayers revealed that an unfavorable conformational change of the linker connecting mononitroxides could be one of the reasons for moderate DNP enhancements. Further, differential scanning calorimetry (DSC) and CW EPR experiments indicated an inhomogeneous distribution and/or a possibility of a partial aggregation of ToSMTSL-PTE in DMPC:DMPA bilayers when the concentration of the polarizing agent was increased to 20 mol% to maximize the DNP enhancement. Thus, conformational changes and an inhomogeneous distribution of the lipid-based biradicals in lipid bilayers emerged as important factors to consider for further development of this matrix-free approach for DNP of membrane proteins.
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Affiliation(s)
- Daryl B Good
- Department of Physics and Biophysics Interdepartmental Group, University of Guelph, Guelph, Ontario, Canada
| | - Maxim A Voinov
- Department of Chemistry, North Carolina State University, Raleigh, NC, USA
| | - David Bolton
- Department of Physics and Biophysics Interdepartmental Group, University of Guelph, Guelph, Ontario, Canada
| | - Meaghan E Ward
- Department of Physics and Biophysics Interdepartmental Group, University of Guelph, Guelph, Ontario, Canada
| | | | | | - Peter Scheffer
- Department of Physics and Biophysics Interdepartmental Group, University of Guelph, Guelph, Ontario, Canada
| | - Andy Lo
- Department of Physics and Biophysics Interdepartmental Group, University of Guelph, Guelph, Ontario, Canada
| | | | - Antonin Marek
- Department of Chemistry, North Carolina State University, Raleigh, NC, USA
| | - Leonid S Brown
- Department of Physics and Biophysics Interdepartmental Group, University of Guelph, Guelph, Ontario, Canada
| | - Alex I Smirnov
- Department of Chemistry, North Carolina State University, Raleigh, NC, USA; Bruker Biospin, Billerica, MA, USA.
| | - Vlad Ladizhansky
- Department of Physics and Biophysics Interdepartmental Group, University of Guelph, Guelph, Ontario, Canada; Bruker Biospin, Billerica, MA, USA.
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15
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Gupta R, Zhang H, Lu M, Hou G, Caporini M, Rosay M, Maas W, Struppe J, Ahn J, Byeon IJL, Oschkinat H, Jaudzems K, Barbet-Massin E, Emsley L, Pintacuda G, Lesage A, Gronenborn AM, Polenova T. Dynamic Nuclear Polarization Magic-Angle Spinning Nuclear Magnetic Resonance Combined with Molecular Dynamics Simulations Permits Detection of Order and Disorder in Viral Assemblies. J Phys Chem B 2019; 123:5048-5058. [PMID: 31125232 DOI: 10.1021/acs.jpcb.9b02293] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We report dynamic nuclear polarization (DNP)-enhanced magic-angle spinning (MAS) NMR spectroscopy in viral capsids from HIV-1 and bacteriophage AP205. Viruses regulate their life cycles and infectivity through modulation of their structures and dynamics. While static structures of capsids from several viruses are now accessible with near-atomic-level resolution, atomic-level understanding of functionally important motions in assembled capsids is lacking. We observed up to 64-fold signal enhancements by DNP, which permitted in-depth analysis of these assemblies. For the HIV-1 CA assemblies, a remarkably high spectral resolution in the 3D and 2D heteronuclear data sets permitted the assignment of a significant fraction of backbone and side-chain resonances. Using an integrated DNP MAS NMR and molecular dynamics (MD) simulation approach, the conformational space sampled by the assembled capsid at cryogenic temperatures was mapped. Qualitatively, a remarkable agreement was observed for the experimental 13C/15N chemical shift distributions and those calculated from substructures along the MD trajectory. Residues that are mobile at physiological temperatures are frozen out in multiple conformers at cryogenic conditions, resulting in broad experimental and calculated chemical shift distributions. Overall, our results suggest that DNP MAS NMR measurements in combination with MD simulations facilitate a thorough understanding of the dynamic signatures of viral capsids.
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Affiliation(s)
- Rupal Gupta
- Department of Chemistry and Biochemistry , University of Delaware , Newark , Delaware 19716 , United States
| | - Huilan Zhang
- Department of Chemistry and Biochemistry , University of Delaware , Newark , Delaware 19716 , United States
| | - Manman Lu
- Department of Chemistry and Biochemistry , University of Delaware , Newark , Delaware 19716 , United States
| | - Guangjin Hou
- Department of Chemistry and Biochemistry , University of Delaware , Newark , Delaware 19716 , United States
| | - Marc Caporini
- Bruker Biospin Corporation , 15 Fortune Drive , Billerica , Massachusetts 01821 , United States
| | - Melanie Rosay
- Bruker Biospin Corporation , 15 Fortune Drive , Billerica , Massachusetts 01821 , United States
| | - Werner Maas
- Bruker Biospin Corporation , 15 Fortune Drive , Billerica , Massachusetts 01821 , United States
| | - Jochem Struppe
- Bruker Biospin Corporation , 15 Fortune Drive , Billerica , Massachusetts 01821 , United States
| | | | | | - Hartmut Oschkinat
- Leibniz-Institut für Molekulare Pharmakologie , Robert-Roessle-Str. 10 , 13125 Berlin , Germany
| | - Kristaps Jaudzems
- Centre de RMN à Très Hauts Champs , Institut des Sciences Analytiques, UMR 5280 CNRS / Ecole Normale Supérieure de Lyon , 5 Rue de la Doua , Villeurbanne, 69100 Lyon , France
| | - Emeline Barbet-Massin
- Centre de RMN à Très Hauts Champs , Institut des Sciences Analytiques, UMR 5280 CNRS / Ecole Normale Supérieure de Lyon , 5 Rue de la Doua , Villeurbanne, 69100 Lyon , France
| | - Lyndon Emsley
- Institut des Sciences et Ingénierie Chimques , Ecole Polytechnique Fédérale de Lausanne (EPFL) CH-1015 Lausanne , Switzerland
| | - Guido Pintacuda
- Centre de RMN à Très Hauts Champs , Institut des Sciences Analytiques, UMR 5280 CNRS / Ecole Normale Supérieure de Lyon , 5 Rue de la Doua , Villeurbanne, 69100 Lyon , France
| | - Anne Lesage
- Centre de RMN à Très Hauts Champs , Institut des Sciences Analytiques, UMR 5280 CNRS / Ecole Normale Supérieure de Lyon , 5 Rue de la Doua , Villeurbanne, 69100 Lyon , France
| | | | - Tatyana Polenova
- Department of Chemistry and Biochemistry , University of Delaware , Newark , Delaware 19716 , United States
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16
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Stevanato G, Kubicki DJ, Menzildjian G, Chauvin AS, Keller K, Yulikov M, Jeschke G, Mazzanti M, Emsley L. A Factor Two Improvement in High-Field Dynamic Nuclear Polarization from Gd(III) Complexes by Design. J Am Chem Soc 2019; 141:8746-8751. [DOI: 10.1021/jacs.9b03723] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Gabriele Stevanato
- Laboratory of
Magnetic Resonance, Institut des Sciences et Ingéniere Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Dominik Józef Kubicki
- Laboratory of
Magnetic Resonance, Institut des Sciences et Ingéniere Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Georges Menzildjian
- Laboratory of
Magnetic Resonance, Institut des Sciences et Ingéniere Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Anne-Sophie Chauvin
- Group of Coordination
Chemistry, Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Katharina Keller
- Laboratory of Inorganic
Chemistry, Department of Chemistry, Laboratory, ETH Zurich, 8093 Zurich, Switzerland
| | - Maxim Yulikov
- Laboratory of Inorganic
Chemistry, Department of Chemistry, Laboratory, ETH Zurich, 8093 Zurich, Switzerland
| | - Gunnar Jeschke
- Laboratory of Inorganic
Chemistry, Department of Chemistry, Laboratory, ETH Zurich, 8093 Zurich, Switzerland
| | - Marinella Mazzanti
- Group of Coordination
Chemistry, Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Lyndon Emsley
- Laboratory of
Magnetic Resonance, Institut des Sciences et Ingéniere Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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17
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Lu M, Wang M, Sergeyev IV, Quinn CM, Struppe J, Rosay M, Maas W, Gronenborn AM, Polenova T. 19F Dynamic Nuclear Polarization at Fast Magic Angle Spinning for NMR of HIV-1 Capsid Protein Assemblies. J Am Chem Soc 2019; 141:5681-5691. [PMID: 30871317 PMCID: PMC6521953 DOI: 10.1021/jacs.8b09216] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
We report remarkably high, up to 100-fold, signal enhancements in 19F dynamic nuclear polarization (DNP) magic angle spinning (MAS) spectra at 14.1 T on HIV-1 capsid protein (CA) assemblies. These enhancements correspond to absolute sensitivity ratios of 12-29 and are of similar magnitude to those seen for 1H signals in the same samples. At MAS frequencies above 20 kHz, it was possible to record 2D 19F-13C HETCOR spectra, which contain long-range intra- and intermolecular correlations. Such correlations provide unique distance restraints, inaccessible in conventional experiments without DNP, for protein structure determination. Furthermore, systematic quantification of the DNP enhancements as a function of biradical concentration, MAS frequency, temperature, and microwave power is reported. Our work establishes the power of DNP-enhanced 19F MAS NMR spectroscopy for structural characterization of HIV-1 CA assemblies, and this approach is anticipated to be applicable to a wide range of large biomolecular systems.
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Affiliation(s)
- Manman Lu
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
- Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, 1051 Biomedical Science Tower 3, 3501 Fifth Ave., Pittsburgh, PA 15261, United States
- Department of Structural Biology, University of Pittsburgh School of Medicine, 3501 Fifth Ave., Pittsburgh, PA 15261, United States
| | - Mingzhang Wang
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
- Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, 1051 Biomedical Science Tower 3, 3501 Fifth Ave., Pittsburgh, PA 15261, United States
| | - Ivan V. Sergeyev
- Bruker Biospin Corporation, 15 Fortune Drive, Billerica, MA, United States
| | - Caitlin M. Quinn
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Jochem Struppe
- Bruker Biospin Corporation, 15 Fortune Drive, Billerica, MA, United States
| | - Melanie Rosay
- Bruker Biospin Corporation, 15 Fortune Drive, Billerica, MA, United States
| | - Werner Maas
- Bruker Biospin Corporation, 15 Fortune Drive, Billerica, MA, United States
| | - Angela M. Gronenborn
- Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, 1051 Biomedical Science Tower 3, 3501 Fifth Ave., Pittsburgh, PA 15261, United States
- Department of Structural Biology, University of Pittsburgh School of Medicine, 3501 Fifth Ave., Pittsburgh, PA 15261, United States
| | - Tatyana Polenova
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
- Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, 1051 Biomedical Science Tower 3, 3501 Fifth Ave., Pittsburgh, PA 15261, United States
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18
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Zhao EW, Maligal-Ganesh R, Mentink-Vigier F, Zhao TY, Du Y, Pei Y, Huang W, Bowers CR. Atomic-Scale Structure of Mesoporous Silica-Encapsulated Pt and PtSn Nanoparticles Revealed by Dynamic Nuclear Polarization- Enhanced 29Si MAS NMR Spectroscopy. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2019; 123:7299-7307. [PMID: 31186824 PMCID: PMC6558955 DOI: 10.1021/acs.jpcc.9b01782] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Mesoporous silica encapsulated Pt (Pt@mSiO2) and PtSn (PtSn@mSiO2) nanoparticles (NPs) are representatives of a novel class of heterogeneous catalysts with uniform particle size, enhanced catalytic properties, and superior thermal stability. In the ship-in-a-bottle synthesis, PtSn@mSiO2 intermetallic NPs are derived from Pt@mSiO2 seeds where the mSiO2 shell is formed by polymerization of tetraethyl orthosilicate around a tetradecyltrimethylammonium bromide template, a surfactant used to template MCM-41. Incorporation of Sn into the Pt@mSiO2 seeds is accommodated by chemical etching of the mSiO2 shell. The effect of this etching on the atomic-scale structure of the mSiO2 has not been previously examined, nor has the extent of the structural similarity to MCM-41. Here, the quaternary Q2, Q3 and Q4 sites corresponding to formulas Si(O1/2)2(OH)2, Si(O1/2)3(OH)1 and Si(O1/2)4, in MCM-41 and the mesoporous silica of Pt@mSiO2 and PtSn@mSiO2 NPs were identified and quantified by conventional and dynamic nuclear polarization enhanced Si-29 Magic Angle Spinning Nuclear Magnetic Resonance (DNP MAS NMR). The connectivity of the -Si-O-Si-network was revealed by DNP enhanced two-dimensional 29Si-29Si correlation spectroscopy.
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Affiliation(s)
- Evan Wenbo Zhao
- Department of Chemistry, University of Florida,
Gainesville, Florida, 32611 United States
- Correspondence to:
, ,
| | | | | | - Tommy Yunpu Zhao
- Department of Chemistry, University of Florida,
Gainesville, Florida, 32611 United States
| | - Yong Du
- Department of Chemistry, University of Florida,
Gainesville, Florida, 32611 United States
| | - Yuchen Pei
- Department of Chemistry, Iowa State University, Ames, Iowa,
50011 United States
| | - Wenyu Huang
- Department of Chemistry, Iowa State University, Ames, Iowa,
50011 United States
- Ames Laboratory, U.S. Department of Energy, Ames, Iowa
50011 United States
- Correspondence to:
, ,
| | - Clifford Russell Bowers
- Department of Chemistry, University of Florida,
Gainesville, Florida, 32611 United States
- Correspondence to:
, ,
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19
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Brodrecht M, Kumari B, Thankamony ASSL, Breitzke H, Gutmann T, Buntkowsky G. Structural Insights into Peptides Bound to the Surface of Silica Nanopores. Chemistry 2019; 25:5214-5221. [DOI: 10.1002/chem.201805480] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Indexed: 11/10/2022]
Affiliation(s)
- Martin Brodrecht
- Institut für Physikalische ChemieTechnische Universität Darmstadt 64287 Darmstadt Germany
| | - Bharti Kumari
- Institut für Physikalische ChemieTechnische Universität Darmstadt 64287 Darmstadt Germany
| | | | - Hergen Breitzke
- Institut für Physikalische ChemieTechnische Universität Darmstadt 64287 Darmstadt Germany
| | - Torsten Gutmann
- Institut für Physikalische ChemieTechnische Universität Darmstadt 64287 Darmstadt Germany
| | - Gerd Buntkowsky
- Institut für Physikalische ChemieTechnische Universität Darmstadt 64287 Darmstadt Germany
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20
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Klimavicius V, Neumann S, Kunz S, Gutmann T, Buntkowsky G. Room temperature CO oxidation catalysed by supported Pt nanoparticles revealed by solid-state NMR and DNP spectroscopy. Catal Sci Technol 2019. [DOI: 10.1039/c9cy00684b] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A series of 1 and 2 nm sized platinum nanoparticles deposited on different support materials are investigated by solid-state NMR combined with dynamic nuclear polarization (DNP).
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Affiliation(s)
- Vytautas Klimavicius
- TU Darmstadt
- Eduard-Zintl-Institute for Inorganic and Physical Chemistry
- 64287 Darmstadt
- Germany
| | - Sarah Neumann
- University of Bremen
- Institute for Applied and Physical Chemistry
- 28359 Bremen
- Germany
| | - Sebastian Kunz
- University of Bremen
- Institute for Applied and Physical Chemistry
- 28359 Bremen
- Germany
| | - Torsten Gutmann
- TU Darmstadt
- Eduard-Zintl-Institute for Inorganic and Physical Chemistry
- 64287 Darmstadt
- Germany
- University Kassel
| | - Gerd Buntkowsky
- TU Darmstadt
- Eduard-Zintl-Institute for Inorganic and Physical Chemistry
- 64287 Darmstadt
- Germany
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21
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Li W, Zhang Q, Joos JJ, Smet PF, Schmedt Auf der Günne J. Blind spheres of paramagnetic dopants in solid state NMR. Phys Chem Chem Phys 2019; 21:10185-10194. [PMID: 31063169 DOI: 10.1039/c9cp00953a] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Solid-state NMR on paramagnetically doped crystal structures gives information about the spatial distribution of dopants in the host. Paramagnetic dopants may render NMR active nuclei virtually invisible by relaxation, paramagnetic broadening or shielding. In this contribution blind sphere radii r0 have been reported, which could be extracted through fitting the NMR signal visibility function f(x) = exp(-ar03x) to experimental data obtained on several model compound series: La1-xLnxPO4 (Ln = Nd, Sm, Gd, Dy, Ho, Er, Tm, Yb), Sr1-xEuxGa2S4 and (Zn1-xMnx)3(PO4)2·4H2O. Radii were extracted for 1H, 31P and 71Ga, and dopants like Nd3+, Gd3+, Dy3+, Ho3+, Er3+, Tm3+, Yb3+ and Mn2+. The observed radii determined differed in all cases and covered a range from 5.5 to 13.5 Å. While these radii were obtained from the amount of invisible NMR signal, we also show how to link the visibility function to lineshape parameters. We show under which conditions empirical correlations of linewidth and doping concentration can be used to extract blind sphere radii from second moment or linewidth parameter data. From the second moment analysis of La1-xSmxPO431P MAS NMR spectra for example, a blind sphere size of Sm3+ can be determined, even though the visibility function remains close to 100% over the entire doping range. Dependence of the blind sphere radius r0 on the NMR isotope and on the paramagnetic dopant could be suggested and verified: for different nuclei, r0 shows a -dependence, γ being the gyromagnetic ratio. The blind sphere radii r0 for different paramagnetic dopants in a lanthanide series could be predicted from the pseudo-contact term.
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Affiliation(s)
- Wenyu Li
- Inorganic Materials Chemistry, University of Siegen, Adolf-Reichwein-Str. 2, 57076 Siegen, Germany.
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22
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Enhanced dynamic nuclear polarization via swept microwave frequency combs. Proc Natl Acad Sci U S A 2018; 115:10576-10581. [PMID: 30279178 DOI: 10.1073/pnas.1807125115] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Dynamic nuclear polarization (DNP) has enabled enormous gains in magnetic resonance signals and led to vastly accelerated NMR/MRI imaging and spectroscopy. Unlike conventional cw-techniques, DNP methods that exploit the full electron spectrum are appealing since they allow direct participation of all electrons in the hyperpolarization process. Such methods typically entail sweeps of microwave radiation over the broad electron linewidth to excite DNP but are often inefficient because the sweeps, constrained by adiabaticity requirements, are slow. In this paper, we develop a technique to overcome the DNP bottlenecks set by the slow sweeps, using a swept microwave frequency comb that increases the effective number of polarization transfer events while respecting adiabaticity constraints. This allows a multiplicative gain in DNP enhancement, scaling with the number of comb frequencies and limited only by the hyperfine-mediated electron linewidth. We demonstrate the technique for the optical hyperpolarization of 13C nuclei in powdered microdiamonds at low fields, increasing the DNP enhancement from 30 to 100 measured with respect to the thermal signal at 7T. For low concentrations of broad linewidth electron radicals [e.g., TEMPO ((2,2,6,6-tetramethylpiperidin-1-yl)oxyl)], these multiplicative gains could exceed an order of magnitude.
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23
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Sesti EL, Saliba EP, Alaniva N, Barnes AB. Electron decoupling with cross polarization and dynamic nuclear polarization below 6 K. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 295:1-5. [PMID: 30077145 PMCID: PMC7015119 DOI: 10.1016/j.jmr.2018.07.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 07/17/2018] [Accepted: 07/21/2018] [Indexed: 05/05/2023]
Abstract
Dynamic nuclear polarization (DNP) can improve nuclear magnetic resonance (NMR) sensitivity by orders of magnitude. Polarizing agents containing unpaired electrons required for DNP can broaden nuclear resonances in the presence of appreciable hyperfine couplings. Here we present the first cross polarization experiments implemented with electron decoupling, which attenuates detrimental hyperfine couplings. We also demonstrate magic angle spinning (MAS) DNP experiments below 6 K, producing unprecedented nuclear spin polarization in rotating solids. 13C correlation spectra were collected with MAS DNP below 6 K for the first time. Polarization build-up times with MAS DNP (T1DNP, 1H) of urea in a frozen glassy matrix below 6 K were measured for both the solid effect and the cross effect. Trityl radicals exhibit a T1DNP (1H) of 18.7 s and the T1DNP (1H) of samples doped with 20 mM AMUPol is only 1.3 s. MAS below 6 K with DNP and electron decoupling is an effective strategy to increase NMR signal-to-noise ratios per transient while retaining short polarization periods.
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Affiliation(s)
- Erika L Sesti
- 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
| | - Nicholas Alaniva
- 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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24
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Jaudzems K, Polenova T, Pintacuda G, Oschkinat H, Lesage A. DNP NMR of biomolecular assemblies. J Struct Biol 2018; 206:90-98. [PMID: 30273657 DOI: 10.1016/j.jsb.2018.09.011] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 09/13/2018] [Accepted: 09/27/2018] [Indexed: 11/30/2022]
Abstract
Dynamic Nuclear Polarization (DNP) is an effective approach to alleviate the inherently low sensitivity of solid-state NMR (ssNMR) under magic angle spinning (MAS) towards large-sized multi-domain complexes and assemblies. DNP relies on a polarization transfer at cryogenic temperatures from unpaired electrons to adjacent nuclei upon continuous microwave irradiation. This is usually made possible via the addition in the sample of a polarizing agent. The first pioneering experiments on biomolecular assemblies were reported in the early 2000s on bacteriophages and membrane proteins. Since then, DNP has experienced tremendous advances, with the development of extremely efficient polarizing agents or with the introduction of new microwaves sources, suitable for NMR experiments at very high magnetic fields (currently up to 900 MHz). After a brief introduction, several experimental aspects of DNP enhanced NMR spectroscopy applied to biomolecular assemblies are discussed. Recent demonstration experiments of the method on viral capsids, the type III and IV bacterial secretion systems, ribosome and membrane proteins are then described.
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Affiliation(s)
- Kristaps Jaudzems
- Centre de RMN à Très Hauts Champs, Institut des Sciences Analytiques (UMR 5280 - CNRS, ENS Lyon, UCB Lyon 1), Université de Lyon, 5 rue de la Doua, 69100 Villeurbanne, France
| | - Tatyana Polenova
- Department of Chemistry and Biochemistry, University of Delaware, 163 The Green, DE 19716, USA
| | - Guido Pintacuda
- Centre de RMN à Très Hauts Champs, Institut des Sciences Analytiques (UMR 5280 - CNRS, ENS Lyon, UCB Lyon 1), Université de Lyon, 5 rue de la Doua, 69100 Villeurbanne, France
| | - Hartmut Oschkinat
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie im Forschungsverbund Berlin e.V. (FMP), Campus Berlin-Buch Robert-Roessle-Str. 10 13125 Berlin, Germany
| | - Anne Lesage
- Centre de RMN à Très Hauts Champs, Institut des Sciences Analytiques (UMR 5280 - CNRS, ENS Lyon, UCB Lyon 1), Université de Lyon, 5 rue de la Doua, 69100 Villeurbanne, France
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25
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Cao W, Wang WD, Xu HS, Sergeyev IV, Struppe J, Wang X, Mentink-Vigier F, Gan Z, Xiao MX, Wang LY, Chen GP, Ding SY, Bai S, Wang W. Exploring Applications of Covalent Organic Frameworks: Homogeneous Reticulation of Radicals for Dynamic Nuclear Polarization. J Am Chem Soc 2018; 140:6969-6977. [PMID: 29799739 PMCID: PMC6045815 DOI: 10.1021/jacs.8b02839] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Rapid progress has been witnessed in the past decade in the fields of covalent organic frameworks (COFs) and dynamic nuclear polarization (DNP). In this contribution, we bridge these two fields by constructing radical-embedded COFs as promising DNP agents. Via polarization transfer from unpaired electrons to nuclei, DNP realizes significant enhancement of NMR signal intensities. One of the crucial issues in DNP is to screen for suitable radicals to act as efficient polarizing agents, the basic criteria for which are homogeneous distribution and fixed orientation of unpaired electrons. We therefore envisioned that the crystalline and porous structures of COFs, if evenly embedded with radicals, may work as a new "crystalline sponge" for DNP experiments. As a proof of concept, we constructed a series of proxyl-radical-embedded COFs (denoted as PR( x)-COFs) and successfully applied them to achieve substantial DNP enhancement. Benefiting from the bottom-up and multivariate synthetic strategies, proxyl radicals have been covalently reticulated, homogeneously distributed, and rigidly embedded into the crystalline and mesoporous frameworks with adjustable concentration ( x%). Excellent performance of PR( x)-COFs has been observed for DNP 1H, 13C, and 15N solid-state NMR enhancements. This contribution not only realizes the direct construction of radical COFs from radical monomers, but also explores the new application of COFs as DNP polarizing agents. Given that many radical COFs can therefore be rationally designed and facilely constructed with well-defined composition, distribution, and pore size, we expect that our effort will pave the way for utilizing radical COFs as standard polarizing agents in DNP NMR experiments.
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Affiliation(s)
- Wei Cao
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering , Lanzhou University , Lanzhou , Gansu 730000 , China
| | - Wei David Wang
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering , Lanzhou University , Lanzhou , Gansu 730000 , China
| | - Hai-Sen Xu
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering , Lanzhou University , Lanzhou , Gansu 730000 , China
| | - Ivan V Sergeyev
- Bruker BioSpin Corporation , 15 Fortune Drive , Billerica , Massachusetts 01821 , United States
| | - Jochem Struppe
- Bruker BioSpin Corporation , 15 Fortune Drive , Billerica , Massachusetts 01821 , United States
| | - Xiaoling Wang
- National High Magnetic Field Laboratory , Florida State University , Tallahassee , Florida 32310 , United States
| | - Frederic Mentink-Vigier
- National High Magnetic Field Laboratory , Florida State University , Tallahassee , Florida 32310 , United States
| | - Zhehong Gan
- National High Magnetic Field Laboratory , Florida State University , Tallahassee , Florida 32310 , United States
| | - Ming-Xing Xiao
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering , Lanzhou University , Lanzhou , Gansu 730000 , China
| | - Lu-Yao Wang
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering , Lanzhou University , Lanzhou , Gansu 730000 , China
| | - Guo-Peng Chen
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering , Lanzhou University , Lanzhou , Gansu 730000 , China
| | - San-Yuan Ding
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering , Lanzhou University , Lanzhou , Gansu 730000 , China
| | - Shi Bai
- Department of Chemistry and Biochemistry , University of Delaware , Newark , Delaware 19716 , United States
| | - Wei Wang
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering , Lanzhou University , Lanzhou , Gansu 730000 , China
- Collaborative Innovation Center of Chemical Science and Engineering , Tianjin 300071 , China
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26
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Rogawski R, Sergeyev IV, Zhang Y, Tran TH, Li Y, Tong L, McDermott AE. NMR Signal Quenching from Bound Biradical Affinity Reagents in DNP Samples. J Phys Chem B 2017; 121:10770-10781. [PMID: 29116793 PMCID: PMC5842680 DOI: 10.1021/acs.jpcb.7b08274] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
We characterize the effect of specifically bound biradicals on the NMR spectra of dihydrofolate reductase from E. coli. Dynamic nuclear polarization methods enhance the signal-to-noise of solid state NMR experiments by transferring polarization from unpaired electrons of biradicals to nuclei. There has been recent interest in colocalizing the paramagnetic polarizing agents with the analyte of interest through covalent or noncovalent specific interactions. This experimental approach broadens the scope of dynamic nuclear polarization methods by offering the possibility of selective signal enhancements and the potential to work in a broad range of environments. Paramagnetic compounds can have other effects on the NMR spectroscopy of nearby nuclei, including broadening of nuclear resonances due to the proximity of the paramagnetic agent. Understanding the distance dependence of these interactions is important for the success of the technique. Here we explore paramagnetic signal quenching due to a bound biradical, specifically a biradical-derivatized trimethoprim ligand of E. coli dihydrofolate reductase. Biradical-derivatized trimethoprim has nanomolar affinity for its target, and affords strong and selective signal enhancements in dynamic nuclear polarization experiments. In this work, we show that, although the trimethoprim fragment is well ordered, the biradical (TOTAPOL) moiety is disordered when bound to the protein. The distance dependence in bleaching of NMR signal intensity allows us to detect numerous NMR signals in the protein. We present the possibility that static disorder and electron spin diffusion play roles in this observation, among other contributions. The fact that the majority of signals are observed strengthens the case for the use of high affinity or covalent radicals in dynamic nuclear polarization solid state NMR enhancement.
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Affiliation(s)
- Rivkah Rogawski
- Department of Chemistry, Columbia University , New York, New York 10027, United States
| | - Ivan V Sergeyev
- Department of Chemistry, Columbia University , New York, New York 10027, United States
| | - Yinglu Zhang
- Department of Biological Sciences, Columbia University , New York, New York 10027, United States
| | - Timothy H Tran
- Department of Biological Sciences, Columbia University , New York, New York 10027, United States
| | - Yongjun Li
- Department of Chemistry, Columbia University , New York, New York 10027, United States
| | - Liang Tong
- Department of Biological Sciences, Columbia University , New York, New York 10027, United States
| | - Ann E McDermott
- Department of Chemistry, Columbia University , New York, New York 10027, United States
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27
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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: 268] [Impact Index Per Article: 38.3] [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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28
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Kobayashi T, Perras FA, Chaudhary U, Slowing II, Huang W, Sadow AD, Pruski M. Improved strategies for DNP-enhanced 2D 1H-X heteronuclear correlation spectroscopy of surfaces. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2017; 87:38-44. [PMID: 28834782 DOI: 10.1016/j.ssnmr.2017.08.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 08/04/2017] [Accepted: 08/08/2017] [Indexed: 06/07/2023]
Abstract
We demonstrate that dynamic nuclear polarization (DNP)-enhanced 1H-X heteronuclear correlation (HETCOR) measurements of hydrogen-rich surface species are better accomplished by using proton-free solvents. This approach notably prevents HETCOR spectra from being obfuscated by the solvent-derived signals otherwise present in DNP measurements. Additionally, in the hydrogen-rich materials studied here, which included functionalized mesoporous silica nanoparticles and metal organic frameworks, the use of proton-free solvents afforded higher sensitivity gains than the commonly used solvents containing protons. We also explored the possibility of using a solvent-free sample formulation and the feasibility of indirect detection in DNP-enhanced HETCOR experiments.
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Affiliation(s)
| | | | - Umesh Chaudhary
- Department of Chemistry, Iowa State University, IA 50011, USA
| | - Igor I Slowing
- Ames Laboratory, U.S. Department of Energy, Ames, IA 50011, USA; Department of Chemistry, Iowa State University, IA 50011, USA
| | - Wenyu Huang
- Ames Laboratory, U.S. Department of Energy, Ames, IA 50011, USA; Department of Chemistry, Iowa State University, IA 50011, USA
| | - Aaron D Sadow
- Ames Laboratory, U.S. Department of Energy, Ames, IA 50011, USA; Department of Chemistry, Iowa State University, IA 50011, USA
| | - Marek Pruski
- Ames Laboratory, U.S. Department of Energy, Ames, IA 50011, USA; Department of Chemistry, Iowa State University, IA 50011, USA.
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29
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Rogawski R, McDermott AE. New NMR tools for protein structure and function: Spin tags for dynamic nuclear polarization solid state NMR. Arch Biochem Biophys 2017; 628:102-113. [PMID: 28623034 PMCID: PMC5815514 DOI: 10.1016/j.abb.2017.06.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 06/05/2017] [Accepted: 06/12/2017] [Indexed: 12/13/2022]
Abstract
Magic angle spinning solid state NMR studies of biological macromolecules [1-3] have enabled exciting studies of membrane proteins [4,5], amyloid fibrils [6], viruses, and large macromolecular assemblies [7]. Dynamic nuclear polarization (DNP) provides a means to enhance detection sensitivity for NMR, particularly for solid state NMR, with many recent biological applications and considerable contemporary efforts towards elaboration and optimization of the DNP experiment. This review explores precedents and innovations in biological DNP experiments, especially highlighting novel chemical biology approaches to introduce the radicals that serve as a source of polarization in DNP experiments.
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Affiliation(s)
- Rivkah Rogawski
- Department of Chemistry, Columbia University, NY, NY 10027, United States
| | - Ann E McDermott
- Department of Chemistry, Columbia University, NY, NY 10027, United States.
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30
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Chen H, Cai S, Chen Z. A method for longitudinal relaxation time measurement in inhomogeneous fields. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2017; 281:118-124. [PMID: 28586739 DOI: 10.1016/j.jmr.2017.05.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 05/13/2017] [Accepted: 05/16/2017] [Indexed: 06/07/2023]
Abstract
The spin-lattice relaxation time (T1) plays a crucial role in the study of spin dynamics, signal optimization and data quantification. However, the measurement of chemical shift-specific T1 constants is hampered by the magnetic field inhomogeneity due to poorly shimmed external magnetic fields or intrinsic magnetic susceptibility heterogeneity in samples. In this study, we present a new protocol to determine chemical shift-specific T1 constants in inhomogeneous fields. Based on intermolecular double-quantum coherences, the new method can resolve overlapped peaks in inhomogeneous fields. The measurement results are in consistent with the measurements in homogeneous fields using the conventional method. Since spatial encoding technique is involved, the experimental time for the new method is very close to that for the conventional method. With the aid of T1 knowledge, some concealed information can be exploited by T1 weighting experiments.
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Affiliation(s)
- Hao Chen
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, Xiamen University, Xiamen, Fujian 361005, China
| | - Shuhui Cai
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, Xiamen University, Xiamen, Fujian 361005, China.
| | - Zhong Chen
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, Xiamen University, Xiamen, Fujian 361005, China
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31
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Viger-Gravel J, Berruyer P, Gajan D, Basset JM, Lesage A, Tordo P, Ouari O, Emsley L. Frozen Acrylamide Gels as Dynamic Nuclear Polarization Matrices. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201703758] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Jasmine Viger-Gravel
- Institut des Sciences et Ingénierie Chimiques; Ecole Polytechnique Fédérale de Lausanne (EPFL); 1015 Lausanne Switzerland
| | - Pierrick Berruyer
- Université de Lyon; Institut des Sciences Analytiques (UMR 5280 CNRS/UCBL/ENS Lyon), Centre de RMN à Très Hauts Champs; 69100 Villeurbanne France
| | - David Gajan
- Université de Lyon; Institut des Sciences Analytiques (UMR 5280 CNRS/UCBL/ENS Lyon), Centre de RMN à Très Hauts Champs; 69100 Villeurbanne France
| | - Jean-Marie Basset
- King Abdullah University of Science and Technology (KAUST); KAUST Catalysis Center (KCC); Thuwal 23955-6900 Saudi Arabia
| | - Anne Lesage
- Université de Lyon; Institut des Sciences Analytiques (UMR 5280 CNRS/UCBL/ENS Lyon), Centre de RMN à Très Hauts Champs; 69100 Villeurbanne France
| | - Paul Tordo
- Aix Marseille Uni, CNRS, ICR UMR 7273; 13397 Marseille France
| | - Olivier Ouari
- Aix Marseille Uni, CNRS, ICR UMR 7273; 13397 Marseille France
| | - Lyndon Emsley
- Institut des Sciences et Ingénierie Chimiques; Ecole Polytechnique Fédérale de Lausanne (EPFL); 1015 Lausanne Switzerland
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32
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Frozen Acrylamide Gels as Dynamic Nuclear Polarization Matrices. Angew Chem Int Ed Engl 2017; 56:8726-8730. [DOI: 10.1002/anie.201703758] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Indexed: 01/08/2023]
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33
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DeHaven BA, Tokarski JT, Korous AA, Mentink-Vigier F, Makris TM, Brugh AM, Forbes MDE, van Tol J, Bowers CR, Shimizu LS. Persistent Radicals of Self-assembled Benzophenone bis-Urea Macrocycles: Characterization and Application as a Polarizing Agent for Solid-state DNP MAS Spectroscopy. Chemistry 2017; 23:8315-8319. [PMID: 28423212 PMCID: PMC5724385 DOI: 10.1002/chem.201701705] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Indexed: 12/22/2022]
Abstract
UV-irradiation of a self-assembled benzophenone bis-urea macrocycle generates μm amounts of radicals that persist for weeks under ambient conditions. High-field EPR and variable-temperature X-band EPR studies suggest a resonance stabilized radical pair through H-abstraction. These endogenous radicals were applied as a polarizing agent for magic angle spinning (MAS) dynamic nuclear polarization (DNP) NMR enhancement. The field-stepped DNP enhancement profile exhibits a sharp peak with a maximum enhancement of ϵon/off =4 superimposed on a nearly constant DNP enhancement of ϵon/off =2 over a broad field range. This maximum coincides with the high field EPR absorption spectrum, consistent with an Overhauser effect mechanism. DNP enhancement was observed for both the host and guests, suggesting that even low levels of endogenous radicals can facilitate the study of host-guest relationships in the solid-state.
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Affiliation(s)
- Baillie A DeHaven
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina, 29208, USA
| | - John T Tokarski
- Department of Chemistry, University of Florida, Gainesville, Florida, 32611, USA
| | - Arthur A Korous
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina, 29208, USA
| | - Frederic Mentink-Vigier
- National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac Drive, Tallahassee, Florida, 32310, USA
| | - Thomas M Makris
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina, 29208, USA
| | - Alexander M Brugh
- Department of Chemistry and Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio, 43403, USA
| | - Malcolm D E Forbes
- Department of Chemistry and Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio, 43403, USA
| | - Johan van Tol
- National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac Drive, Tallahassee, Florida, 32310, USA
| | - Clifford R Bowers
- Department of Chemistry, University of Florida, Gainesville, Florida, 32611, USA
| | - Linda S Shimizu
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina, 29208, USA
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34
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Saliba EP, Sesti EL, Scott FJ, Albert BJ, Choi EJ, Alaniva N, Gao C, Barnes AB. Electron Decoupling with Dynamic Nuclear Polarization in Rotating Solids. J Am Chem Soc 2017; 139:6310-6313. [DOI: 10.1021/jacs.7b02714] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Edward P. Saliba
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Erika L. Sesti
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Faith J. Scott
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Brice J. Albert
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Eric J. Choi
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Nicholas Alaniva
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Chukun Gao
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Alexander B. Barnes
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
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35
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Rogawski R, Sergeyev IV, Li Y, Ottaviani MF, Cornish V, McDermott AE. Dynamic Nuclear Polarization Signal Enhancement with High-Affinity Biradical Tags. J Phys Chem B 2017; 121:1169-1175. [PMID: 28099013 DOI: 10.1021/acs.jpcb.6b09021] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Dynamic nuclear polarization is an emerging technique for sensitizing solid-state NMR experiments by transferring polarization from electrons to nuclei. Stable biradicals, the polarization source for the cross effect mechanism, are typically codissolved at millimolar concentrations with proteins of interest. Here we describe the high-affinity biradical tag TMP-T, created by covalently linking trimethoprim, a nanomolar affinity ligand of dihydrofolate reductase (DHFR), to the biradical polarizing agent TOTAPOL. With TMP-T bound to DHFR, large enhancements of the protein spectrum are observed, comparable to when TOTAPOL is codissolved with the protein. In contrast to TOTAPOL, the tight binding TMP-T can be added stoichiometrically at radical concentrations orders of magnitude lower than in previously described preparations. Benefits of the reduced radical concentration include reduced spectral bleaching, reduced chemical perturbation of the sample, and the ability to selectively enhance signals for the protein of interest.
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Affiliation(s)
- Rivkah Rogawski
- Department of Chemistry, Columbia University , New York, New York 10027, United States
| | - Ivan V Sergeyev
- Department of Chemistry, Columbia University , New York, New York 10027, United States
| | - Yongjun Li
- Department of Chemistry, Columbia University , New York, New York 10027, United States
| | - M Francesca Ottaviani
- Department of Pure and Applied Sciences, University of Urbino , Loc. Crocicchia, 61029 Urbino, Italy
| | - Virginia Cornish
- Department of Chemistry, Columbia University , New York, New York 10027, United States
| | - Ann E McDermott
- Department of Chemistry, Columbia University , New York, New York 10027, United States
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36
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Akbey Ü, Oschkinat H. Structural biology applications of solid state MAS DNP NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 269:213-224. [PMID: 27095695 DOI: 10.1016/j.jmr.2016.04.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 04/05/2016] [Accepted: 04/05/2016] [Indexed: 06/05/2023]
Abstract
Dynamic Nuclear Polarization (DNP) has long been an aim for increasing sensitivity of nuclear magnetic resonance (NMR) spectroscopy, delivering spectra in shorter experiment times or of smaller sample amounts. In recent years, it has been applied in magic angle spinning (MAS) solid-state NMR to a large range of samples, including biological macromolecules and functional materials. New research directions in structural biology can be envisaged by DNP, facilitating investigations on very large complexes or very heterogeneous samples. Here we present a summary of state of the art DNP MAS NMR spectroscopy and its applications to structural biology, discussing the technical challenges and factors affecting DNP performance.
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Affiliation(s)
- Ümit Akbey
- Aarhus Institute of Advanced Studies (AIAS), Aarhus University, Høegh-Guldbergs Gade 6B, 8000 Aarhus C, Denmark; Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus C, Denmark.
| | - Hartmut Oschkinat
- Leibniz Institute für Molekulare Pharmakologie (FMP), NMR Supported Structural Biology, Robert Roessle Str. 10, 13125 Berlin, Germany.
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37
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Chaudhari SR, Berruyer P, Gajan D, Reiter C, Engelke F, Silverio DL, Copéret C, Lelli M, Lesage A, Emsley L. Dynamic nuclear polarization at 40 kHz magic angle spinning. Phys Chem Chem Phys 2016; 18:10616-22. [PMID: 27035630 PMCID: PMC5048395 DOI: 10.1039/c6cp00839a] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 03/11/2016] [Indexed: 01/07/2023]
Abstract
DNP-enhanced solid-state NMR spectroscopy under magic angle spinning (MAS) is rapidly developing into a powerful analytical tool to investigate the structure of a wide range of solid materials, because it provides unsurpassed sensitivity gains. Most developments and applications of DNP MAS NMR were so far reported at moderate spinning frequencies (up to 14 kHz using 3.2 mm rotors). Here, using a 1.3 mm MAS DNP probe operating at 18.8 T and ∼100 K, we show that signal amplification factors can be increased by up to a factor two when using smaller volume rotors as compared to 3.2 mm rotors, and report enhancements of around 60 over a range of sample spinning rates from 10 to 40 kHz. Spinning at 40 kHz is also shown to increase (29)Si coherence lifetimes by a factor three as compared to 10 kHz, substantially increasing sensitivity in CPMG type experiments. The contribution of quenching effects to the overall sensitivity gain at very fast MAS is evaluated, and applications are reported on a functionalised mesostructured organic-inorganic material.
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Affiliation(s)
- Sachin R. Chaudhari
- Institut de Sciences Analytiques , Centre de RMN à Très Hauts Champs , Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1) , France .
| | - Pierrick Berruyer
- Institut de Sciences Analytiques , Centre de RMN à Très Hauts Champs , Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1) , France .
| | - David Gajan
- Institut de Sciences Analytiques , Centre de RMN à Très Hauts Champs , Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1) , France .
| | | | | | - Daniel L. Silverio
- ETH Zürich , Department of Chemistry , Vladimir Prelog Weg 1-5 , CH-8093 Zürich , Switzerland
| | - Christophe Copéret
- ETH Zürich , Department of Chemistry , Vladimir Prelog Weg 1-5 , CH-8093 Zürich , Switzerland
| | - Moreno Lelli
- University of Florence , Chemistry Department , Magnetic Resonance Center , 50019 Sesto Fiorentino (FI) , Italy
| | - Anne Lesage
- Institut de Sciences Analytiques , Centre de RMN à Très Hauts Champs , Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1) , France .
| | - Lyndon Emsley
- Institut des Sciences et Ingénierie Chimiques , Ecole Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne , Switzerland .
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38
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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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39
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Frederick KK, Michaelis VK, Corzilius B, Ong TC, Jacavone AC, Griffin RG, Lindquist S. Sensitivity-enhanced NMR reveals alterations in protein structure by cellular milieus. Cell 2015; 163:620-8. [PMID: 26456111 PMCID: PMC4621972 DOI: 10.1016/j.cell.2015.09.024] [Citation(s) in RCA: 112] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 07/03/2015] [Accepted: 08/26/2015] [Indexed: 12/11/2022]
Abstract
Biological processes occur in complex environments containing a myriad of potential interactors. Unfortunately, limitations on the sensitivity of biophysical techniques normally restrict structural investigations to purified systems, at concentrations that are orders of magnitude above endogenous levels. Dynamic nuclear polarization (DNP) can dramatically enhance the sensitivity of nuclear magnetic resonance (NMR) spectroscopy and enable structural studies in biologically complex environments. Here, we applied DNP NMR to investigate the structure of a protein containing both an environmentally sensitive folding pathway and an intrinsically disordered region, the yeast prion protein Sup35. We added an exogenously prepared isotopically labeled protein to deuterated lysates, rendering the biological environment "invisible" and enabling highly efficient polarization transfer for DNP. In this environment, structural changes occurred in a region known to influence biological activity but intrinsically disordered in purified samples. Thus, DNP makes structural studies of proteins at endogenous levels in biological contexts possible, and such contexts can influence protein structure.
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Affiliation(s)
| | - Vladimir K Michaelis
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Björn Corzilius
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Ta-Chung Ong
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Angela C Jacavone
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Robert G Griffin
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Susan Lindquist
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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40
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Wenk P, Kaushik M, Richter D, Vogel M, Suess B, Corzilius B. Dynamic nuclear polarization of nucleic acid with endogenously bound manganese. JOURNAL OF BIOMOLECULAR NMR 2015. [PMID: 26219517 DOI: 10.1007/s10858-015-9972-1] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
We report the direct dynamic nuclear polarization (DNP) of (13)C nuclei of a uniformly [(13)C,(15)N]-labeled, paramagnetic full-length hammerhead ribozyme (HHRz) complex with Mn(2+) where the enhanced polarization is fully provided by the endogenously bound metal ion and no exogenous polarizing agent is added. A (13)C enhancement factor of ε = 8 was observed by intra-complex DNP at 9.4 T. In contrast, "conventional" indirect and direct DNP experiments were performed using AMUPol as polarizing agent where we obtained a (1)H enhancement factor of ε ≈ 250. Comparison with the diamagnetic (Mg(2+)) HHRz complex shows that the presence of Mn(2+) only marginally influences the (DNP-enhanced) NMR properties of the RNA. Furthermore two-dimensional correlation spectra ((15)N-(13)C and (13)C-(13)C) reveal structural inhomogeneity in the frozen, amorphous state indicating the coexistence of several conformational states. These demonstrations of intra-complex DNP using an endogenous metal ion as well as DNP-enhanced MAS NMR of RNA in general yield important information for the development of new methods in structural biology.
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Affiliation(s)
- Patricia Wenk
- Institute of Physical und Theoretical Chemistry, Institute of Biophysical Chemistry und Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University, Max-von-Laue-Str. 7-9, 60438, Frankfurt am Main, Germany
- Werner Siemens Imaging Center and Department of Preclinical Imaging and Radiopharmacy, University of Tübingen, Röntgenweg 13, 72076, Tübingen, Germany
| | - Monu Kaushik
- Institute of Physical und Theoretical Chemistry, Institute of Biophysical Chemistry und Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University, Max-von-Laue-Str. 7-9, 60438, Frankfurt am Main, Germany
| | - Diane Richter
- Institute of Physical und Theoretical Chemistry, Institute of Biophysical Chemistry und Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University, Max-von-Laue-Str. 7-9, 60438, Frankfurt am Main, Germany
| | - Marc Vogel
- Department of Biology, Technical University Darmstadt, Schnittspahnstraße 10, 64287, Darmstadt, Germany
| | - Beatrix Suess
- Department of Biology, Technical University Darmstadt, Schnittspahnstraße 10, 64287, Darmstadt, Germany
| | - Björn Corzilius
- Institute of Physical und Theoretical Chemistry, Institute of Biophysical Chemistry und Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University, Max-von-Laue-Str. 7-9, 60438, Frankfurt am Main, Germany.
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41
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van der Cruijsen EAW, Koers EJ, Sauvée C, Hulse RE, Weingarth M, Ouari O, Perozo E, Tordo P, Baldus M. Biomolecular DNP-Supported NMR Spectroscopy using Site-Directed Spin Labeling. Chemistry 2015; 21:12971-7. [DOI: 10.1002/chem.201501376] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Indexed: 12/24/2022]
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42
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Lee D, Hediger S, De Paëpe G. Is solid-state NMR enhanced by dynamic nuclear polarization? SOLID STATE NUCLEAR MAGNETIC RESONANCE 2015; 66-67:6-20. [PMID: 25779337 DOI: 10.1016/j.ssnmr.2015.01.003] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 01/27/2015] [Accepted: 01/28/2015] [Indexed: 05/03/2023]
Abstract
The recent trend of high-field (~5-20 T), low-temperature (~100 K) ssNMR combined with dynamic nuclear polarization (DNP) under magic angle spinning (MAS) conditions is analyzed. A brief overview of the current theory of hyperpolarization for so-called MAS-DNP experiments is given, along with various reasons why the DNP-enhancement, the ratio of the NMR signal intensities obtained in the presence and absence of microwave irradiation suitable for hyperpolarization, should not be used alone to gauge the value of performing MAS-DNP experiments relative to conventional ssNMR. This is demonstrated through a dissection of the current conditions required for MAS-DNP with particular attention to resulting absolute sensitivities and spectral resolution. Consequently, sample preparation methods specifically avoiding the surplus of glass-forming solvents so as to improve the absolute sensitivity and resolution are discussed, as are samples that are intrinsically pertinent for MAS-DNP studies (high surface area, amorphous, and porous). Owing to their pertinence, examples of recent applications on these types of samples where chemically-relevant information has been obtained that would have been impossible without the sensitivity increases bestowed by MAS-DNP are also detailed. Additionally, a promising further implementation for MAS-DNP is exampled, whereby the sensitivity improvements shown for (correlation) spectroscopy of nuclei at low natural isotopic abundance, facilitate internuclear distance measurements, especially for long distances (absence of dipolar truncation). Finally, we give some speculative perspectives for MAS-DNP.
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Affiliation(s)
- Daniel Lee
- Univ. Grenoble Alpes, INAC, SCIB, F-38000 Grenoble, France; CEA, INAC, SCIB, F-38000 Grenoble, France.
| | - Sabine Hediger
- Univ. Grenoble Alpes, INAC, SCIB, F-38000 Grenoble, France; CEA, INAC, SCIB, F-38000 Grenoble, France; CNRS, SCIB, F-38000 Grenoble, France
| | - Gaël De Paëpe
- Univ. Grenoble Alpes, INAC, SCIB, F-38000 Grenoble, France; CEA, INAC, SCIB, F-38000 Grenoble, France
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43
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Perez Linde AJ, Chinthalapalli S, Carnevale D, Bodenhausen G. Rotation-induced recovery and bleaching in magnetic resonance. Phys Chem Chem Phys 2015; 17:6415-22. [DOI: 10.1039/c4cp05735j] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A sharp decrease of the longitudinal proton spin relaxation time T1(1H) is observed at 100 K when frozen mixtures of glycerol and H2O doped with lanthanides are made to rotate slowly about the magic angle, in a manner that is reminiscent of spin refrigerators.
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Affiliation(s)
- Angel J. Perez Linde
- Institut des Sciences et Ingénierie Chimiques (ISIC)
- Ecole Polytechnique Fédérale de Lausanne (EPFL)
- 1015 Lausanne
- Switzerland
| | - Srinivas Chinthalapalli
- Institut des Sciences et Ingénierie Chimiques (ISIC)
- Ecole Polytechnique Fédérale de Lausanne (EPFL)
- 1015 Lausanne
- Switzerland
| | - Diego Carnevale
- Institut des Sciences et Ingénierie Chimiques (ISIC)
- Ecole Polytechnique Fédérale de Lausanne (EPFL)
- 1015 Lausanne
- Switzerland
| | - Geoffrey Bodenhausen
- Institut des Sciences et Ingénierie Chimiques (ISIC)
- Ecole Polytechnique Fédérale de Lausanne (EPFL)
- 1015 Lausanne
- Switzerland
- Ecole Normale Supérieure-PSL Research University
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44
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Corzilius B, Michaelis VK, Penzel SA, Ravera E, Smith AA, Luchinat C, Griffin RG. Dynamic nuclear polarization of (1)H, (13)C, and (59)Co in a tris(ethylenediamine)cobalt(III) crystalline lattice doped with Cr(III). J Am Chem Soc 2014; 136:11716-27. [PMID: 25069794 PMCID: PMC4140501 DOI: 10.1021/ja5044374] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The study of inorganic crystalline materials by solid-state NMR spectroscopy is often complicated by the low sensitivity of heavy nuclei. However, these materials often contain or can be prepared with paramagnetic dopants without significantly affecting the structure of the crystalline host. Dynamic nuclear polarization (DNP) is generally capable of enhancing NMR signals by transferring the magnetization of unpaired electrons to the nuclei. Therefore, the NMR sensitivity in these paramagnetically doped crystals might be increased by DNP. In this paper we demonstrate the possibility of efficient DNP transfer in polycrystalline samples of [Co(en)3Cl3]2·NaCl·6H2O (en = ethylenediamine, C2H8N2) doped with Cr(III) in varying concentrations between 0.1 and 3 mol %. We demonstrate that (1)H, (13)C, and (59)Co can be polarized by irradiation of Cr(III) with 140 GHz microwaves at a magnetic field of 5 T. We further explain our findings on the basis of electron paramagnetic resonance spectroscopy of the Cr(III) site and analysis of its temperature-dependent zero-field splitting, as well as the dependence of the DNP enhancement factor on the external magnetic field and microwave power. This first demonstration of DNP transfer from one paramagnetic metal ion to its diamagnetic host metal ion will pave the way for future applications of DNP in paramagnetically doped materials or metalloproteins.
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Affiliation(s)
- Björn Corzilius
- Francis Bitter Magnet Laboratory and Department of Chemistry, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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45
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Yau WM, Thurber KR, Tycko R. Synthesis and evaluation of nitroxide-based oligoradicals for low-temperature dynamic nuclear polarization in solid state NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2014; 244:98-106. [PMID: 24887201 PMCID: PMC4106245 DOI: 10.1016/j.jmr.2014.05.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Revised: 05/02/2014] [Accepted: 05/03/2014] [Indexed: 05/05/2023]
Abstract
We describe the synthesis of new nitroxide-based biradical, triradical, and tetraradical compounds and the evaluation of their performance as paramagnetic dopants in dynamic nuclear polarization (DNP) experiments in solid state nuclear magnetic resonance (NMR) spectroscopy with magic-angle spinning (MAS). Under our experimental conditions, which include temperatures in the 25-30 K range, a 9.4 T magnetic field, MAS frequencies of 6.2-6.8 kHz, and microwave irradiation at 264.0 GHz from a 800 mW extended interaction oscillator source, the most effective compounds are triradicals that are related to the previously-described compound DOTOPA-TEMPO (see Thurber et al., 2010), but have improved solubility in glycerol/water solvent near neutral pH. Using these compounds at 30 mM total nitroxide concentration, we observe DNP enhancement factors of 92-128 for cross-polarized (13)C NMR signals from (15)N,(13)C-labeled melittin in partially protonated glycerol/water, and build-up times of 2.6-3.8s for (1)H spin polarizations. Net sensitivity enhancements with biradical and tetraradical dopants, taking into account absolute (13)C NMR signal amplitudes and build-up times, are approximately 2-4 times lower than with the best triradicals.
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Affiliation(s)
- Wai-Ming Yau
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0520, United States
| | - Kent R Thurber
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0520, United States
| | - Robert Tycko
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0520, United States.
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46
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Le D, Casano G, Phan TNT, Ziarelli F, Ouari O, Aussenac F, Thureau P, Mollica G, Gigmes D, Tordo P, Viel S. Optimizing Sample Preparation Methods for Dynamic Nuclear Polarization Solid-state NMR of Synthetic Polymers. Macromolecules 2014. [DOI: 10.1021/ma500788n] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Dao Le
- Aix Marseille Université, CNRS,
ICR UMR 7273, 13397, Marseille, France
| | - Gilles Casano
- Aix Marseille Université, CNRS,
ICR UMR 7273, 13397, Marseille, France
| | - Trang N. T. Phan
- Aix Marseille Université, CNRS,
ICR UMR 7273, 13397, Marseille, France
| | - Fabio Ziarelli
- Aix Marseille Université, CNRS, Centrale Marseille, Fédération
des Sciences Chimiques de Marseille FR 1739, 13397, Marseille, France
| | - Olivier Ouari
- Aix Marseille Université, CNRS,
ICR UMR 7273, 13397, Marseille, France
| | | | - Pierre Thureau
- Aix Marseille Université, CNRS,
ICR UMR 7273, 13397, Marseille, France
| | - Giulia Mollica
- Aix Marseille Université, CNRS,
ICR UMR 7273, 13397, Marseille, France
| | - Didier Gigmes
- Aix Marseille Université, CNRS,
ICR UMR 7273, 13397, Marseille, France
| | - Paul Tordo
- Aix Marseille Université, CNRS,
ICR UMR 7273, 13397, Marseille, France
| | - Stéphane Viel
- Aix Marseille Université, CNRS,
ICR UMR 7273, 13397, Marseille, France
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47
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Thurber KR, Tycko R. Perturbation of nuclear spin polarizations in solid state NMR of nitroxide-doped samples by magic-angle spinning without microwaves. J Chem Phys 2014; 140:184201. [PMID: 24832263 PMCID: PMC4032438 DOI: 10.1063/1.4874341] [Citation(s) in RCA: 110] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 04/21/2014] [Indexed: 01/17/2023] Open
Abstract
We report solid state (13)C and (1)H nuclear magnetic resonance (NMR) experiments with magic-angle spinning (MAS) on frozen solutions containing nitroxide-based paramagnetic dopants that indicate significant perturbations of nuclear spin polarizations without microwave irradiation. At temperatures near 25 K, (1)H and cross-polarized (13)C NMR signals from (15)N,(13)C-labeled L-alanine in trinitroxide-doped glycerol/water are reduced by factors as large as six compared to signals from samples without nitroxide doping. Without MAS or at temperatures near 100 K, differences between signals with and without nitroxide doping are much smaller. We attribute most of the reduction of NMR signals under MAS near 25 K to nuclear spin depolarization through the cross-effect dynamic nuclear polarization mechanism, in which three-spin flips drive nuclear polarizations toward equilibrium with spin polarization differences between electron pairs. When T1e is sufficiently long relative to the MAS rotation period, the distribution of electron spin polarization across the nitroxide electron paramagnetic resonance lineshape can be very different from the corresponding distribution in a static sample at thermal equilibrium, leading to the observed effects. We describe three-spin and 3000-spin calculations that qualitatively reproduce the experimental observations.
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Affiliation(s)
- Kent R Thurber
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, USA
| | - Robert Tycko
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, USA
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48
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Corzilius B, Andreas LB, Smith AA, Ni QZ, Griffin RG. Paramagnet induced signal quenching in MAS-DNP experiments in frozen homogeneous solutions. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2014; 240:113-23. [PMID: 24394190 PMCID: PMC3951579 DOI: 10.1016/j.jmr.2013.11.013] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 11/21/2013] [Accepted: 11/22/2013] [Indexed: 05/06/2023]
Abstract
The effects of nuclear signal quenching induced by the presence of a paramagnetic polarizing agent are documented for conditions used in magic angle spinning (MAS)-dynamic nuclear polarization (DNP) experiments on homogeneous solutions. In particular, we present a detailed analysis of three time constants: (1) the longitudinal build-up time constant TB for (1)H; (2) the rotating frame relaxation time constant T1ρ for (1)H and (13)C and (3) T2 of (13)C, the transverse relaxation time constant in the laboratory frame. These relaxation times were measured during microwave irradiation at a magnetic field of 5 T (140 GHz) as a function of the concentration of four polarizing agents: TOTAPOL, 4-amino-TEMPO, trityl (OX063), and Gd-DOTA and are compared to those obtained for a sample lacking paramagnetic doping. We also report the EPR relaxation time constants T1S and T2S, the DNP enhancements, ε, and the parameter E, defined below, which measures the sensitivity enhancement for the four polarizing agents as a function of the electron concentration. We observe substantial intensity losses (paramagnetic quenching) with all of the polarizing agents due to broadening mechanisms and cross relaxation during MAS. In particular, the monoradical trityl and biradical TOTAPOL induce ∼40% and 50% loss of signal intensity. In contrast there is little suppression of signal intensity in static samples containing these paramagnetic species. Despite the losses due to quenching, we find that all of the polarizing agents provide substantial gains in signal intensity with DNP, and in particular that the net enhancement is optimal for biradicals that operate with the cross effect. We discuss the possibility that much of this polarization loss can be regained with the development of instrumentation and methods to perform electron decoupling.
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Affiliation(s)
- Björn Corzilius
- Francis Bitter Magnet Laboratory, Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Loren B Andreas
- Francis Bitter Magnet Laboratory, Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Albert A Smith
- Francis Bitter Magnet Laboratory, Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Qing Zhe Ni
- Francis Bitter Magnet Laboratory, Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Robert G Griffin
- Francis Bitter Magnet Laboratory, Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
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49
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Michaelis VK, Ong TC, Kiesewetter MK, Frantz DK, Walish JJ, Ravera E, Luchinat C, Swager TM, Griffin RG. Topical Developments in High-Field Dynamic Nuclear Polarization. Isr J Chem 2014; 54:207-221. [PMID: 25977588 DOI: 10.1002/ijch.201300126] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We report our recent efforts directed at improving high-field DNP experiments. We investigated a series of thiourea nitroxide radicals and the associated DNP enhancements ranging from ε = 25 to 82 that demonstrate the impact of molecular structure on performance. We directly polarized low-gamma nuclei including 13C, 2H, and 17O using trityl via the cross effect. We discuss a variety of sample preparation techniques for DNP with emphasis on the benefit of methods that do not use a glass-forming cryoprotecting matrix. Lastly, we describe a corrugated waveguide for use in a 700 MHz / 460 GHz DNP system that improves microwave delivery and increases enhancements up to 50%.
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Affiliation(s)
- Vladimir K Michaelis
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139, USA.,Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139, USA
| | - Ta-Chung Ong
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139, USA.,Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139, USA
| | - Matthew K Kiesewetter
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139, USA
| | - Derik K Frantz
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139, USA
| | - Joseph J Walish
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139, USA
| | - Enrico Ravera
- Department of Chemistry "Ugo Schiff" and Magnetic Resonance Center (CERM) University of Florence, 50019 Sesto Fiorentino (FI), Italy
| | - Claudio Luchinat
- Department of Chemistry "Ugo Schiff" and Magnetic Resonance Center (CERM) University of Florence, 50019 Sesto Fiorentino (FI), Italy
| | - Timothy M Swager
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139, USA
| | - Robert G Griffin
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139, USA.,Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139, USA
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50
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Ravera E, Corzilius B, Michaelis VK, Luchinat C, Griffin RG, Bertini I. DNP-enhanced MAS NMR of bovine serum albumin sediments and solutions. J Phys Chem B 2014; 118:2957-65. [PMID: 24460530 PMCID: PMC3983357 DOI: 10.1021/jp500016f] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
![]()
Protein
sedimentation sans cryoprotection is a new approach to
magic angle spinning (MAS) and dynamic nuclear polarization (DNP)
nuclear magnetic resonance (NMR) spectroscopy of proteins. It increases
the sensitivity of the experiments by a factor of ∼4.5 in comparison
to the conventional DNP sample preparation and circumvents intense
background signals from the cryoprotectant. In this paper, we investigate
sedimented samples and concentrated frozen solutions of natural abundance
bovine serum albumin (BSA) in the absence of a glycerol-based cryoprotectant.
We observe DNP signal enhancements of ε ∼ 66 at 140 GHz
in a BSA pellet sedimented from an aqueous solution containing the
biradical polarizing agent TOTAPOL and compare this with samples prepared
using the conventional protocol (i.e., dissolution of BSA in a glycerol/water
cryoprotecting mixture). The dependence of DNP parameters on the radical
concentration points to the presence of an interaction between TOTAPOL
and BSA, so much so that a frozen solution sans cryoprotectant still
gives ε ∼ 50. We have studied the interaction of BSA
with another biradical, SPIROPOL, that is more rigid than TOTAPOL
and has been reported to give higher enhancements. SPIROPOL was also
found to interact with BSA, and to give ε ∼ 26 close
to its maximum achievable concentration. Under the same conditions,
TOTAPOL gives ε ∼ 31, suggesting a lesser affinity of
BSA for SPIROPOL with respect to TOTAPOL. Altogether, these results
demonstrate that DNP is feasible in self-cryoprotecting samples.
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Affiliation(s)
- Enrico Ravera
- Magnetic Resonance Center (CERM) and Department of Chemistry "Ugo Schiff", University of Florence , 50019 Sesto Fiorentino (FI), Italy
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