1
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Nevzorov AA, Marek A, Milikisiyants S, Smirnov AI. High-frequency high-power DNP/EPR spectrometer operating at 7 T magnetic field. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2024; 362:107677. [PMID: 38631171 PMCID: PMC11102838 DOI: 10.1016/j.jmr.2024.107677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 03/26/2024] [Accepted: 04/09/2024] [Indexed: 04/19/2024]
Abstract
One of the most essential prerequisites for the development of pulse Dynamic Nuclear Polarization (DNP) is the ability to generate high-power coherent mm-wave pulses at the electron precession frequencies corresponding to the magnetic fields of modern high-resolution NMR spectrometers. As a major step towards achieving this goal, an Extended Interaction Klystron (EIK) pulse amplifier custom-built by the Communications and Power Industries, Inc. and producing up to 140 W at 197.8 GHz, was integrated with in-house built NMR/DNP/EPR spectrometer operating at 7 T magnetic field. The spectrometer employs a Thomas Keating, Ltd. quasioptical bridge to direct mm-waves into a homebuilt DNP probe incorporating photonic bandgap (PBG) resonators to further boost electronic B1e fields. Three-pulse electron spin echo nutation experiments were employed to characterize the B1e fields at the sample by operating the homodyne 198 GHz bridge in an induction mode. Room-temperature experiments with a single-crystal high-pressure, high-temperature (HPHT) diamond and a polystyrene film doped with BDPA radical yielded < 9 ns π/2 pulses at ca. 50 W specified EIK output at the corresponding resonance frequencies and the PBG resonator quality factor of Q≈300. DNP experiments carried out in a "gated" mode by supplying 20 μs mm-wave pulses every 1 ms yielded 13C solid-effect DNP with gains up to 20 for the polystyrene-BDPA sample at natural 13C abundance. For a single-crystal HPHT diamond, the gated DNP mode yielded almost the same 13C enhancement as a low-power continuous wave (CW) mode at 0.4 W, whereas no DNP effect was observed for the BDPA/polystyrene sample in the latter case. To illustrate the versatility of our upgraded DNP spectrometer, room-temperature Overhauser DNP enhancements of 7-14 for 31P NMR signal were demonstrated using a liquid droplet of 1 M tri-phenyl phosphine co-dissolved with 100 mM of BDPA in toluene‑d8.
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Affiliation(s)
- Alexander A Nevzorov
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Dr., Raleigh, NC 27695, US.
| | - Antonin Marek
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Dr., Raleigh, NC 27695, US
| | - Sergey Milikisiyants
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Dr., Raleigh, NC 27695, US
| | - Alex I Smirnov
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Dr., Raleigh, NC 27695, US.
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2
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Chatterjee S, Venkatesh A, Sigurdsson ST, Mentink-Vigier F. Role of Protons in and around Strongly Coupled Nitroxide Biradicals for Cross-Effect Dynamic Nuclear Polarization. J Phys Chem Lett 2024; 15:2160-2168. [PMID: 38364262 DOI: 10.1021/acs.jpclett.3c03472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2024]
Abstract
In magic angle spinning dynamic nuclear polarization (DNP), biradicals such as bis-nitroxides are used to hyperpolarize protons under microwave irradiation through the cross-effect mechanism. This mechanism relies on electron-electron spin interactions (dipolar coupling and exchange interaction) and electron-nuclear spin interactions (hyperfine coupling) to hyperpolarize the protons surrounding the biradical. This hyperpolarization is then transferred to the bulk sample via nuclear spin diffusion. However, the involvement of the protons in the biradical in the cross-effect DNP process has been under debate. In this work, we address this question by exploring the hyperpolarization pathways in and around bis-nitroxides. We demonstrate that for biradicals with strong electron-electron interactions, as in the case of the AsymPols, the protons on the biradical may not be necessary to quickly generate hyperpolarization. Instead, such biradicals can efficiently, and directly, polarize the surrounding protons of the solvent. The findings should impact the design of the next generation of biradicals.
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Affiliation(s)
- Satyaki Chatterjee
- University of Iceland, Department of Chemistry, Science Institute, Dunhaga 3, 107 Reykjavik, Iceland
| | - Amrit Venkatesh
- National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac Drive, Tallahassee, Florida 32310, United States
| | - Snorri Th Sigurdsson
- University of Iceland, Department of Chemistry, Science Institute, Dunhaga 3, 107 Reykjavik, Iceland
| | - Frédéric Mentink-Vigier
- National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac Drive, Tallahassee, Florida 32310, United States
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3
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Harrabi R, Halbritter T, Alarab S, Chatterjee S, Wolska-Pietkiewicz M, Damodaran KK, van Tol J, Lee D, Paul S, Hediger S, Sigurdsson ST, Mentink-Vigier F, De Paëpe G. AsymPol-TEKs as efficient polarizing agents for MAS-DNP in glass matrices of non-aqueous solvents. Phys Chem Chem Phys 2024; 26:5669-5682. [PMID: 38288878 PMCID: PMC10849081 DOI: 10.1039/d3cp04271e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 01/22/2024] [Indexed: 02/03/2024]
Abstract
Two polarizing agents from the AsymPol family, AsymPol-TEK and cAsymPol-TEK (methyl-free version) are introduced for MAS-DNP applications in non-aqueous solvents. The performance of these new biradicals is rationalized in detail using a combination of electron paramagnetic resonance spectroscopy, density functional theory, molecular dynamics and quantitative MAS-DNP spin dynamics simulations. By slightly modifying the experimental protocol to keep the sample temperature low at insertion, we are able to obtain reproducable DNP-NMR data with 1,1,2,2-tetrachloroethane (TCE) at 100 K, which facilitates optimization and comparison of different polarizing agents. At intermediate magnetic fields, AsymPol-TEK and cAsymPol-TEK provide 1.5 to 3-fold improvement in sensitivity compared to TEKPol, one of the most widely used polarizing agents for organic solvents, with significantly shorter DNP build-up times of ∼1 s and ∼2 s at 9.4 and 14.1 T respectively. In the course of the work, we also isolated and characterized two diastereoisomers that can form during the synthesis of AsymPol-TEK; their difference in performance is described and discussed. Finally, the advantages of the AsymPol-TEKs are demonstrated by recording 2D 13C-13C correlation experiments at natural 13C-abundance of proton-dense microcrystals and by polarizing the surface of ZnO nanocrystals (NCs) coated with diphenyl phosphate ligands. For those experiments, cAsymPol-TEK yielded a three-fold increase in sensitivity compared to TEKPol, corresponding to a nine-fold time saving.
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Affiliation(s)
- Rania Harrabi
- Univ. Grenoble Alpes, CEA, CNRS, IRIG, MEM, 38000 Grenoble, France.
| | - Thomas Halbritter
- University of Iceland, Department of Chemistry, Science Institute, Dunhaga 3, 107 Reykjavik, Iceland.
| | - Shadi Alarab
- Univ. Grenoble Alpes, CEA, CNRS, IRIG, MEM, 38000 Grenoble, France.
| | - Satyaki Chatterjee
- University of Iceland, Department of Chemistry, Science Institute, Dunhaga 3, 107 Reykjavik, Iceland.
| | | | - Krishna K Damodaran
- University of Iceland, Department of Chemistry, Science Institute, Dunhaga 3, 107 Reykjavik, Iceland.
| | - Johan van Tol
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32301, USA.
| | - Daniel Lee
- Univ. Grenoble Alpes, CEA, CNRS, IRIG, MEM, 38000 Grenoble, France.
| | - Subhradip Paul
- Univ. Grenoble Alpes, CEA, CNRS, IRIG, MEM, 38000 Grenoble, France.
| | - Sabine Hediger
- Univ. Grenoble Alpes, CEA, CNRS, IRIG, MEM, 38000 Grenoble, France.
| | - Snorri Th Sigurdsson
- University of Iceland, Department of Chemistry, Science Institute, Dunhaga 3, 107 Reykjavik, Iceland.
| | - Frederic Mentink-Vigier
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32301, USA.
| | - Gaël De Paëpe
- Univ. Grenoble Alpes, CEA, CNRS, IRIG, MEM, 38000 Grenoble, France.
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4
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Paul S, Bouleau E, Reynard-Feytis Q, Arnaud JP, Bancel F, Rollet B, Dalban-Moreynas P, Reiter C, Purea A, Engelke F, Hediger S, De Paëpe G. Sustainable and cost-effective MAS DNP-NMR at 30 K with cryogenic sample exchange. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2023; 356:107561. [PMID: 37837749 DOI: 10.1016/j.jmr.2023.107561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 09/18/2023] [Accepted: 09/22/2023] [Indexed: 10/16/2023]
Abstract
We report here instrumental developments to achieve sustainable, cost-effective cryogenic Helium sample spinning in order to conduct dynamic nuclear polarisation (DNP) and solid-state NMR (ssNMR) at ultra-low temperatures (<30 K). More specifically, we describe an efficient closed-loop helium system composed of a powerful heat exchanger (95% efficient), a single cryocooler, and a single helium compressor to power the sample spinning and cooling. The system is integrated with a newly designed triple-channel NMR probe that minimizes thermal losses without compromising the radio frequency (RF) performance and spinning stability (±0.05%). The probe is equipped with an innovative cryogenic sample exchange system that allows swapping samples in minutes without introducing impurities in the closeloop system. We report that significant gain in sensitivity can be obtained at 30-40 K on large micro-crystalline molecules with unfavorable relaxation timescales, making them difficult or impossible to polarize at 100 K. We also report rotor-synchronized 2D experiments to demonstrate the stability of the system.
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Affiliation(s)
- Subhradip Paul
- Univ. Grenoble. Alpes, CEA, CNRS, IRIG, MEM, 38000 Grenoble, France
| | - Eric Bouleau
- Univ. Grenoble Alpes, CEA, IRIG, DSBT, 38000 Grenoble, France
| | | | | | - Florian Bancel
- Univ. Grenoble Alpes, CEA, IRIG, DSBT, 38000 Grenoble, France
| | - Bertrand Rollet
- Univ. Grenoble Alpes, CEA, IRIG, DSBT, 38000 Grenoble, France
| | | | | | | | | | - Sabine Hediger
- Univ. Grenoble. Alpes, CEA, CNRS, IRIG, MEM, 38000 Grenoble, France
| | - Gaël De Paëpe
- Univ. Grenoble. Alpes, CEA, CNRS, IRIG, MEM, 38000 Grenoble, France.
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5
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Menzildjian G, Schlagnitweit J, Casano G, Ouari O, Gajan D, Lesage A. Polarizing agents for efficient high field DNP solid-state NMR spectroscopy under magic-angle spinning: from design principles to formulation strategies. Chem Sci 2023; 14:6120-6148. [PMID: 37325158 PMCID: PMC10266460 DOI: 10.1039/d3sc01079a] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 05/09/2023] [Indexed: 06/17/2023] Open
Abstract
Dynamic Nuclear Polarization (DNP) has recently emerged as a cornerstone approach to enhance the sensitivity of solid-state NMR spectroscopy under Magic Angle Spinning (MAS), opening unprecedented analytical opportunities in chemistry and biology. DNP relies on a polarization transfer from unpaired electrons (present in endogenous or exogenous polarizing agents) to nearby nuclei. Developing and designing new polarizing sources for DNP solid-state NMR spectroscopy is currently an extremely active research field per se, that has recently led to significant breakthroughs and key achievements, in particular at high magnetic fields. This review describes recent developments in this area, highlighting key design principles that have been established over time and led to the introduction of increasingly more efficient polarizing sources. After a short introduction, Section 2 presents a brief history of solid-state DNP, highlighting the main polarization transfer schemes. The third section is devoted to the development of dinitroxide radicals, discussing the guidelines that were progressively established to design the fine-tuned molecular structures in use today. In Section 4, we describe recent efforts in developing hybrid radicals composed of a narrow EPR line radical covalently linked to a nitroxide, highlighting the parameters that modulate the DNP efficiency of these mixed structures. Section 5 reviews recent advances in the design of metal complexes suitable for DNP MAS NMR as exogenous electron sources. In parallel, current strategies that exploit metal ions as endogenous polarization sources are discussed. Section 6 briefly describes the recent introduction of mixed-valence radicals. In the last part, experimental aspects regarding sample formulation are reviewed to make best use of these polarizing agents in a broad panel of application fields.
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Affiliation(s)
- Georges Menzildjian
- Centre de RMN à, Très Hauts Champs, Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1) 5 Rue de la doua 69100 Villeurbanne France
| | - Judith Schlagnitweit
- Centre de RMN à, Très Hauts Champs, Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1) 5 Rue de la doua 69100 Villeurbanne France
| | - Gilles Casano
- Aix Marseille Univ., CNRS, Institut de Chimie Radicalaire, UMR 7273 Marseille France
| | - Olivier Ouari
- Aix Marseille Univ., CNRS, Institut de Chimie Radicalaire, UMR 7273 Marseille France
| | - David Gajan
- Centre de RMN à, Très Hauts Champs, Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1) 5 Rue de la doua 69100 Villeurbanne France
| | - Anne Lesage
- Centre de RMN à, Très Hauts Champs, Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1) 5 Rue de la doua 69100 Villeurbanne France
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6
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Armstrong CM, Snively EC, Shumail M, Nantista C, Li Z, Tantawi S, Loo BW, Temkin RJ, Griffin RG, Feng J, Dionisio R, Mentgen F, Ayllon N, Henderson MA, Goodman TP. Frontiers in the Application of RF Vacuum Electronics. IEEE TRANSACTIONS ON ELECTRON DEVICES 2023; 70:2643-2655. [PMID: 37250956 PMCID: PMC10216895 DOI: 10.1109/ted.2023.3239841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The application of radio frequency (RF) vacuum electronics for the betterment of the human condition began soon after the invention of the first vacuum tubes in the 1920s and has not stopped since. Today, microwave vacuum devices are powering important applications in health treatment, material and biological science, wireless communication-terrestrial and space, Earth environment remote sensing, and the promise of safe, reliable, and inexhaustible energy. This article highlights some of the exciting application frontiers of vacuum electronics.
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Affiliation(s)
| | - Emma C Snively
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025 USA
| | | | | | - Zenghai Li
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025 USA
| | - Sami Tantawi
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025 USA
| | - Bill W Loo
- Department of Radiation Oncology and Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA 94305 USA
| | - Richard J Temkin
- Department of Physics and the Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
| | - Robert G Griffin
- Department of Chemistry and the Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
| | - Jinjun Feng
- Beijing Vacuum Electronics Research Institute, Beijing 100015, China
| | - Roberto Dionisio
- RF Equipment and Technologies Section, European Space Agency (ESA), NL-2200 AG Noordwijk, The Netherlands
| | - Felix Mentgen
- RF Equipment and Technologies Section, European Space Agency (ESA), NL-2200 AG Noordwijk, The Netherlands
| | - Natanael Ayllon
- RF Equipment and Technologies Section, European Space Agency (ESA), NL-2200 AG Noordwijk, The Netherlands
| | - Mark A Henderson
- United Kingdom Atomic Energy Authority, Culham Science Centre, OX14 3DB Abingdon, U.K
| | - Timothy P Goodman
- Swiss Plasma Center, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
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7
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Kumar A, Watbled B, Baussanne I, Hediger S, Demeunynck M, De Paëpe G. Optimizing chemistry at the surface of prodrug-loaded cellulose nanofibrils with MAS-DNP. Commun Chem 2023; 6:58. [PMID: 36977767 PMCID: PMC10049993 DOI: 10.1038/s42004-023-00852-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 03/09/2023] [Indexed: 03/30/2023] Open
Abstract
Studying the surface chemistry of functionalized cellulose nanofibrils at atomic scale is an ongoing challenge, mainly because FT-IR, NMR, XPS and RAMAN spectroscopy are limited in sensitivity or resolution. Herein, we show that dynamic nuclear polarization (DNP) enhanced 13C and 15N solid-state NMR is a uniquely suited technique to optimize the drug loading on nanocellulose using aqueous heterogenous chemistry. We compare the efficiency of two conventional coupling agents (DMTMM vs EDC/NHS) to bind a complex prodrug of ciprofloxacin designed for controlled drug release. Besides quantifying the drug grafting, we also evidence the challenge to control the concurrent prodrug adsorption and to optimize washing procedures. We notably highlight the presence of an unexpected prodrug cleavage mechanism triggered by carboxylates at the surface of the cellulose nanofibrils.
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Affiliation(s)
- Akshay Kumar
- Univ. Grenoble Alpes, CEA, CNRS, IRIG-MEM, Grenoble, France
| | | | | | - Sabine Hediger
- Univ. Grenoble Alpes, CEA, CNRS, IRIG-MEM, Grenoble, France
| | | | - Gaël De Paëpe
- Univ. Grenoble Alpes, CEA, CNRS, IRIG-MEM, Grenoble, France.
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8
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Chen J, Wang F, Wen Y, Tang W, Peng L. Emerging Applications of 17O Solid-State NMR Spectroscopy for Catalytic Oxides. ACS Catal 2023. [DOI: 10.1021/acscatal.2c06267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Affiliation(s)
- Junchao Chen
- Key Laboratory of Mesoscopic Chemistry of Ministry of Education and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Fang Wang
- Key Laboratory of Mesoscopic Chemistry of Ministry of Education and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Yujie Wen
- Key Laboratory of Mesoscopic Chemistry of Ministry of Education and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Weiping Tang
- School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Luming Peng
- Key Laboratory of Mesoscopic Chemistry of Ministry of Education and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
- Jiangsu Key Laboratory of Vehicle Emissions Control, Nanjing University, Nanjing 210093, China
- Frontiers Science Center for Critical Earth Material Cycling (FSC-CEMaC), Nanjing University, Nanjing, Jiangsu 210023, China
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9
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Eills J, Budker D, Cavagnero S, Chekmenev EY, Elliott SJ, Jannin S, Lesage A, Matysik J, Meersmann T, Prisner T, Reimer JA, Yang H, Koptyug IV. Spin Hyperpolarization in Modern Magnetic Resonance. Chem Rev 2023; 123:1417-1551. [PMID: 36701528 PMCID: PMC9951229 DOI: 10.1021/acs.chemrev.2c00534] [Citation(s) in RCA: 62] [Impact Index Per Article: 62.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Magnetic resonance techniques are successfully utilized in a broad range of scientific disciplines and in various practical applications, with medical magnetic resonance imaging being the most widely known example. Currently, both fundamental and applied magnetic resonance are enjoying a major boost owing to the rapidly developing field of spin hyperpolarization. Hyperpolarization techniques are able to enhance signal intensities in magnetic resonance by several orders of magnitude, and thus to largely overcome its major disadvantage of relatively low sensitivity. This provides new impetus for existing applications of magnetic resonance and opens the gates to exciting new possibilities. In this review, we provide a unified picture of the many methods and techniques that fall under the umbrella term "hyperpolarization" but are currently seldom perceived as integral parts of the same field. Specifically, before delving into the individual techniques, we provide a detailed analysis of the underlying principles of spin hyperpolarization. We attempt to uncover and classify the origins of hyperpolarization, to establish its sources and the specific mechanisms that enable the flow of polarization from a source to the target spins. We then give a more detailed analysis of individual hyperpolarization techniques: the mechanisms by which they work, fundamental and technical requirements, characteristic applications, unresolved issues, and possible future directions. We are seeing a continuous growth of activity in the field of spin hyperpolarization, and we expect the field to flourish as new and improved hyperpolarization techniques are implemented. Some key areas for development are in prolonging polarization lifetimes, making hyperpolarization techniques more generally applicable to chemical/biological systems, reducing the technical and equipment requirements, and creating more efficient excitation and detection schemes. We hope this review will facilitate the sharing of knowledge between subfields within the broad topic of hyperpolarization, to help overcome existing challenges in magnetic resonance and enable novel applications.
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Affiliation(s)
- James Eills
- Institute
for Bioengineering of Catalonia, Barcelona
Institute of Science and Technology, 08028Barcelona, Spain,
| | - Dmitry Budker
- Johannes
Gutenberg-Universität Mainz, 55128Mainz, Germany,Helmholtz-Institut,
GSI Helmholtzzentrum für Schwerionenforschung, 55128Mainz, Germany,Department
of Physics, UC Berkeley, Berkeley, California94720, United States
| | - Silvia Cavagnero
- Department
of Chemistry, University of Wisconsin, Madison, Madison, Wisconsin53706, United States
| | - Eduard Y. Chekmenev
- Department
of Chemistry, Integrative Biosciences (IBio), Karmanos Cancer Institute
(KCI), Wayne State University, Detroit, Michigan48202, United States,Russian
Academy of Sciences, Moscow119991, Russia
| | - Stuart J. Elliott
- Molecular
Sciences Research Hub, Imperial College
London, LondonW12 0BZ, United Kingdom
| | - Sami Jannin
- Centre
de RMN à Hauts Champs de Lyon, Université
de Lyon, CNRS, ENS Lyon, Université Lyon 1, 69100Villeurbanne, France
| | - Anne Lesage
- Centre
de RMN à Hauts Champs de Lyon, Université
de Lyon, CNRS, ENS Lyon, Université Lyon 1, 69100Villeurbanne, France
| | - Jörg Matysik
- Institut
für Analytische Chemie, Universität
Leipzig, Linnéstr. 3, 04103Leipzig, Germany
| | - Thomas Meersmann
- Sir
Peter Mansfield Imaging Centre, University Park, School of Medicine, University of Nottingham, NottinghamNG7 2RD, United Kingdom
| | - Thomas Prisner
- Institute
of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic
Resonance, Goethe University Frankfurt, , 60438Frankfurt
am Main, Germany
| | - Jeffrey A. Reimer
- Department
of Chemical and Biomolecular Engineering, UC Berkeley, and Materials Science Division, Lawrence Berkeley National
Laboratory, Berkeley, California94720, United States
| | - Hanming Yang
- Department
of Chemistry, University of Wisconsin, Madison, Madison, Wisconsin53706, United States
| | - Igor V. Koptyug
- International Tomography Center, Siberian
Branch of the Russian Academy
of Sciences, 630090Novosibirsk, Russia,
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10
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Palani RS, Mardini M, Delage-Laurin L, Banks D, Ouyang Y, Bryerton E, Kempf JG, Swager TM, Griffin RG. Amplified Overhauser DNP with Selective Deuteration: Attenuation of Double-Quantum Cross-Relaxation. J Phys Chem Lett 2023; 14:95-100. [PMID: 36573841 PMCID: PMC9903202 DOI: 10.1021/acs.jpclett.2c03087] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
We recently used selective 2H labeling of BDPA to investigate the Overhauser Effect (OE) dynamic nuclear polarization (DNP) mechanism in insulating solids doped with 1,3-bis(diphenylene)-2-phenylallyl (BDPA), and established that the α and γ 1H spins on the fluorene rings are responsible for generating a zero quantum (ZQ) mediated positive bulk polarization. Here, we establish that the phenyl 1H spins relax via double-quantum (DQ) processes and therefore contribute negative enhancements which attenuate the OE-DNP. With measurements at different magnetic field strengths, we show that phenyl-d5-BDPA offers >50% improvement in OE-DNP enhancement compared to h21-BDPA attaining a maximum of ∼90 at 14.1 T and 5 kHz MAS, the highest observed OE-DNP enhancement to date under these conditions. The approach may be utilized to optimize other polarizing agents exhibiting an OE, an important DNP mechanism with a favorable field and spinning frequency dependence.
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Affiliation(s)
| | | | | | - Daniel Banks
- Bruker Biospin Corporation, Billerica, Massachusetts 01821, United States
| | | | - Eric Bryerton
- Virginia Diodes Corporation, Charlottesville, Virginia 22902, United States
| | - James G Kempf
- Bruker Biospin Corporation, Billerica, Massachusetts 01821, United States
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11
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Michaelis VK, Keeler EG, Bahri S, Ong TC, Daviso E, Colvin MT, Griffin RG. Biradical Polarizing Agents at High Fields. J Phys Chem B 2022; 126:7847-7856. [PMID: 36194539 PMCID: PMC9886493 DOI: 10.1021/acs.jpcb.2c03985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The sensitivity enhancements available from dynamic nuclear polarization (DNP) are rapidly reshaping the research landscape and expanding the field of nuclear magnetic resonance (NMR) spectroscopy as a tool for solving complex chemical and structural problems. The past decade has seen considerable advances in this burgeoning method, while efforts to further improve its capabilities continue along many avenues. In this report, we examine the influence of static magnetic field strength and temperature on the reported 1H DNP enhancements from three conventional organic biradicals: TOTAPOL, AMUPol, and SPIROPOL. In contrast to the conventional wisdom, our findings show that at liquid nitrogen temperatures and 700 MHz/460.5 GHz, these three bisnitroxides all provide similar 1H DNP enhancements, ε ≈ 60. Furthermore, we investigate the influence of temperature, microwave power, magnetic field strength, and protein sample deuteration on the NMR experimental results.
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Affiliation(s)
- Vladimir K. Michaelis
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge 02139 Massachusetts, United States; Department of Chemistry, University of Alberta, Edmonton T6G 2G2 Alberta, Canada
| | - Eric G. Keeler
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge 02139 Massachusetts, United States; New York Structural Biology Center, New York 10027, New York, United States
| | - Salima Bahri
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge 02139 Massachusetts, United States; Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht 3584CH, The Netherlands
| | - Ta-Chung Ong
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge 02139 Massachusetts, United States; Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles 90095 California, United States
| | - Eugenio Daviso
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge 02139 Massachusetts, United States; Department of Scientific Support and Applications Development, Covaris LLC, Woburn 01801 Massachusetts, United States
| | - Michael T. Colvin
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge 02139 Massachusetts, United States; Ortho Clinical Diagnostics, Rochester 14626 New York, United States
| | - Robert G. Griffin
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge 02139 Massachusetts, United States
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12
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Pang Z, Jain S, Yang C, Kong X, Tan KO. A unified description for polarization-transfer mechanisms in magnetic resonance in static solids: Cross polarization and DNP. J Chem Phys 2022; 156:244109. [DOI: 10.1063/5.0092265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Polarization transfers are crucial building blocks in magnetic resonance experiments, i.e., they can be used to polarize insensitive nuclei and correlate nuclear spins in multidimensional nuclear magnetic resonance (NMR) spectroscopy. The polarization can be transferred either across different nuclear spin species or from electron spins to the relatively low-polarized nuclear spins. The former route occurring in solid-state NMR can be performed via cross polarization (CP), while the latter route is known as dynamic nuclear polarization (DNP). Despite having different operating conditions, we opinionate that both mechanisms are theoretically similar processes in ideal conditions, i.e., the electron is merely another spin-1/2 particle with a much higher gyromagnetic ratio. Here, we show that the CP and DNP processes can be described using a unified theory based on average Hamiltonian theory combined with fictitious operators. The intuitive and unified approach has allowed new insights into the cross-effect DNP mechanism, leading to better design of DNP polarizing agents and extending the applications beyond just hyperpolarization. We explore the possibility of exploiting theoretically predicted DNP transients for electron–nucleus distance measurements—such as routine dipolar-recoupling experiments in solid-state NMR.
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Affiliation(s)
- Zhenfeng Pang
- Department of Chemistry, Zhejiang University, 310027 Hangzhou, China
- Laboratoire des Biomolécules, LBM, Département de Chimie, École Normale Supérieure, PSL University, Sorbonne Université, CNRS, 75005 Paris, France
| | - Sheetal Jain
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| | - Chen Yang
- Amazon Robotics, 300 Riverpark Drive, North Reading, Massachusetts 01864, USA
| | - Xueqian Kong
- Department of Chemistry, Zhejiang University, 310027 Hangzhou, China
| | - Kong Ooi Tan
- Laboratoire des Biomolécules, LBM, Département de Chimie, École Normale Supérieure, PSL University, Sorbonne Université, CNRS, 75005 Paris, France
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13
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Jabbour R, Renom-Carrasco M, Chan KW, Völker L, Berruyer P, Wang Z, Widdifield CM, Lelli M, Gajan D, Copéret C, Thieuleux C, Lesage A. Multiple Surface Site Three-Dimensional Structure Determination of a Supported Molecular Catalyst. J Am Chem Soc 2022; 144:10270-10281. [PMID: 35642739 DOI: 10.1021/jacs.2c01013] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The structural characterization of supported molecular catalysts is challenging due to the low density of active sites and the presence of several organic/organometallic surface groups resulting from the often complex surface chemistry associated with support functionalization. Here, we provide a complete atomic-scale description of all surface sites in an N-heterocyclic carbene based on iridium and supported on silica, at all stages of its synthesis. By combining a suitable isotope labeling strategy with the implementation of multinuclear dipolar recoupling DNP-enhanced NMR experiments, the 3D structure of the Ir-NHC sites, as well as that of the synthesis intermediates were determined. As a significant fraction of parent surface fragments does not react during the multistep synthesis, site-selective experiments were implemented to specifically probe proximities between the organometallic groups and the solid support. The NMR-derived structure of the iridium sites points to a well-defined conformation. By interpreting EXAFS spectroscopy and chemical analysis data augmented by computational studies, the presence of two coordination geometries is demonstrated: Ir-NHC fragments coordinated by a 1,5-cyclooctadiene and one Cl ligand, as well as, more surprisingly, a fragment coordinated by two NHC and two Cl ligands. This study demonstrates a unique methodology to disclose individual surface structures in complex, multisite environments, a long-standing challenge in the field of heterogeneous/supported catalysts, while revealing new, unexpected structural features of metallo-NHC-supported substrates. It also highlights the potentially large diversity of surface sites present in functional materials prepared by surface chemistry, an essential knowledge to design materials with improved performances.
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Affiliation(s)
- Ribal Jabbour
- Université de Lyon, CNRS, ENS Lyon, Université Lyon 1, Centre de RMN de Lyon, UMR 5082, 5 rue de la Doua, 69100 Villeurbanne, France
| | - Marc Renom-Carrasco
- Université de Lyon, Institut de Chimie de Lyon, CP2M, UMR 5128 CNRS-CPE Lyon-UCBL, CPE Lyon, 43 Bvd du 11 Novembre 1918, 69100 Villeurbanne, France
| | - Ka Wing Chan
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1-5/10, 8093 Zürich, Switzerland
| | - Laura Völker
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1-5/10, 8093 Zürich, Switzerland
| | - Pierrick Berruyer
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Zhuoran Wang
- Université de Lyon, CNRS, ENS Lyon, Université Lyon 1, Centre de RMN de Lyon, UMR 5082, 5 rue de la Doua, 69100 Villeurbanne, France
| | - Cory M Widdifield
- Department of Chemistry and Biochemistry, University of Regina, 3737 Wascana Parkway, Regina, SK S4S 0A2, Canada
| | - Moreno Lelli
- Magnetic Resonance Center (CERM), University of Florence, 50019 Sesto Fiorentino, FI, Italy
| | - David Gajan
- Université de Lyon, CNRS, ENS Lyon, Université Lyon 1, Centre de RMN de Lyon, UMR 5082, 5 rue de la Doua, 69100 Villeurbanne, France
| | - Christophe Copéret
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1-5/10, 8093 Zürich, Switzerland
| | - Chloé Thieuleux
- Université de Lyon, Institut de Chimie de Lyon, CP2M, UMR 5128 CNRS-CPE Lyon-UCBL, CPE Lyon, 43 Bvd du 11 Novembre 1918, 69100 Villeurbanne, France
| | - Anne Lesage
- Université de Lyon, CNRS, ENS Lyon, Université Lyon 1, Centre de RMN de Lyon, UMR 5082, 5 rue de la Doua, 69100 Villeurbanne, France
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14
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Elathram N, Ackermann BE, Debelouchina GT. DNP-enhanced solid-state NMR spectroscopy of chromatin polymers. JOURNAL OF MAGNETIC RESONANCE OPEN 2022; 10-11:100057. [PMID: 35707629 PMCID: PMC9191766 DOI: 10.1016/j.jmro.2022.100057] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Chromatin is a DNA-protein polymer that represents the functional form of the genome. The main building block of chromatin is the nucleosome, a structure that contains 147 base pairs of DNA and two copies each of the histone proteins H2A, H2B, H3 and H4. Previous work has shown that magic angle spinning (MAS) NMR spectroscopy can capture the nucleosome at high resolution although studies have been challenging due to low sensitivity, the presence of dynamic and rigid components, and the complex interaction networks of nucleosomes within the chromatin polymer. Here, we use dynamic nuclear polarization (DNP) to enhance the sensitivity of MAS NMR experiments of nucleosome arrays at 100 K and show that well-resolved 13C-13C MAS NMR correlations can be obtained much more efficiently. We evaluate the effect of temperature on the chemical shifts and linewidths in the spectra and demonstrate that changes are relatively minimal and clustered in regions of histone-DNA or histone-histone contacts. We also compare samples prepared with and without DNA and show that the low temperature 13C-13C correlations exhibit sufficient resolution to detect chemical shift changes and line broadening for residues that form the DNA-histone interface. On the other hand, we show that the measurement of DNP-enhanced 15N-13C histone-histone interactions within the nucleosome core is complicated by the natural 13C abundance network in the sample. Nevertheless, the enhanced sensitivity afforded by DNP can be used to detect long-range correlations between histone residues and DNA. Overall, our experiments demonstrate that DNP-enhanced MAS NMR spectroscopy of chromatin samples yields spectra with high resolution and sensitivity and can be used to capture functionally relevant protein-DNA interactions that have implications for gene regulation and genome organization.
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Affiliation(s)
| | | | - Galia T. Debelouchina
- Corresponding author: Galia Debelouchina, University of California, San Diego, Natural Sciences Building 4322, 9500 Gilman Dr., La Jolla, CA 92093, 858-534-3038,
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15
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Kundu K, Dubroca T, Rane V, Mentink-Vigier F. Spinning-Driven Dynamic Nuclear Polarization with Optical Pumping. J Phys Chem A 2022; 126:2600-2608. [PMID: 35417169 PMCID: PMC9121629 DOI: 10.1021/acs.jpca.2c01559] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
We propose a new, more efficient, and potentially cost effective, solid-state nuclear spin hyperpolarization method combining the cross-effect mechanism and electron spin optical hyperpolarization in rotating solids. We first demonstrate optical hyperpolarization in the solid state at low temperatures and low field and then investigate its field dependence to obtain the optimal condition for high-field electron spin hyperpolarization. The results are then incorporated into advanced magic-angle spinning dynamic nuclear polarization (MAS-DNP) numerical simulations that show that optically pumped MAS-DNP could yield breakthrough enhancements at very high magnetic fields. Based on these investigations, enhancements greater than the ratio of electron to nucleus magnetic moments (>658 for 1H) are possible without microwave irradiation. This could solve at once the MAS-DNP performance decrease with increasing field and the high cost of MAS-DNP instruments at very high fields.
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Affiliation(s)
- Krishnendu Kundu
- National High Magnetic Field Laboratory, Florida State University, 1800 E Paul Dirac Drive, Tallahassee, Florida 32310, United States
| | - Thierry Dubroca
- National High Magnetic Field Laboratory, Florida State University, 1800 E Paul Dirac Drive, Tallahassee, Florida 32310, United States
| | - Vinayak Rane
- Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
| | - Frederic Mentink-Vigier
- National High Magnetic Field Laboratory, Florida State University, 1800 E Paul Dirac Drive, Tallahassee, Florida 32310, United States
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16
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Chow WY, De Paëpe G, Hediger S. Biomolecular and Biological Applications of Solid-State NMR with Dynamic Nuclear Polarization Enhancement. Chem Rev 2022; 122:9795-9847. [PMID: 35446555 DOI: 10.1021/acs.chemrev.1c01043] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Solid-state NMR spectroscopy (ssNMR) with magic-angle spinning (MAS) enables the investigation of biological systems within their native context, such as lipid membranes, viral capsid assemblies, and cells. However, such ambitious investigations often suffer from low sensitivity due to the presence of significant amounts of other molecular species, which reduces the effective concentration of the biomolecule or interaction of interest. Certain investigations requiring the detection of very low concentration species remain unfeasible even with increasing experimental time for signal averaging. By applying dynamic nuclear polarization (DNP) to overcome the sensitivity challenge, the experimental time required can be reduced by orders of magnitude, broadening the feasible scope of applications for biological solid-state NMR. In this review, we outline strategies commonly adopted for biological applications of DNP, indicate ongoing challenges, and present a comprehensive overview of biological investigations where MAS-DNP has led to unique insights.
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Affiliation(s)
- Wing Ying Chow
- Univ. Grenoble Alpes, CEA, CNRS, Interdisciplinary Research Institute of Grenoble (IRIG), Modeling and Exploration of Materials Laboratory (MEM), 38054 Grenoble, France.,Univ. Grenoble Alpes, CEA, CNRS, Inst. Biol. Struct. IBS, 38044 Grenoble, France
| | - Gaël De Paëpe
- Univ. Grenoble Alpes, CEA, CNRS, Interdisciplinary Research Institute of Grenoble (IRIG), Modeling and Exploration of Materials Laboratory (MEM), 38054 Grenoble, France
| | - Sabine Hediger
- Univ. Grenoble Alpes, CEA, CNRS, Interdisciplinary Research Institute of Grenoble (IRIG), Modeling and Exploration of Materials Laboratory (MEM), 38054 Grenoble, France
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17
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Wi S, Dwivedi N, Dubey R, Mentink-Vigier F, Sinha N. Dynamic nuclear polarization-enhanced, double-quantum filtered 13C- 13C dipolar correlation spectroscopy of natural 13C abundant bone-tissue biomaterial. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2022; 335:107144. [PMID: 35085899 PMCID: PMC8823282 DOI: 10.1016/j.jmr.2022.107144] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Revised: 01/07/2022] [Accepted: 01/08/2022] [Indexed: 05/03/2023]
Abstract
Here, we describe a method for obtaining a dynamic nuclear polarization (DNP)-enhanced double-quantum filtered (DQF) two-dimensional (2D) dipolar 13C-13C correlation spectra of bone-tissue material at natural 13C abundance. DNP-enhanced DQF 2D dipolar 13C-13C spectra were obtained using a few different mixing times of the dipolar-assisted rotational resonance (DARR) scheme and these spectra were compared to a conventional 2D through-space double-quantum (DQ)-single-quantum (SQ) correlation spectrum. While this scheme can only be used for an assignment purpose to reveal the carbon-carbon connectivity within a residue, the DQF 13C-13C dipolar correlation scheme introduced here can be used to obtain longer distance carbon-carbon constraints. A DQF pulse block is placed before the DARR mixing scheme for removing dominant 13C single-quantum (SQ) signals because these SQ 13C signals are overwhelmingly large compared to those 13C-13C dipolar cross-peaks generated and therefore saturate the dynamic range of the NMR detection. This approach exhibits strong enough 2D cross-peaks in a dipolar 13C-13C correlation spectrum and potentially provides pairwise 13C-13C dipolar constraints because the dipolar truncation effect as well as multi-step signal propagations involving a spin cluster that contains more than two spins can be ignored probabilistically. To obtain fast signal averaging, AsymPolPOK was used to provide a short 1H DNP signal build-up time (1.3 s) and to expedite our MAS DNP NMR acquisitions while still maintaining a satisfactory DNP enhancement factor (ε = 50). Under long DARR mixing, a t1-noise-like artifact was observed at a site that possesses a large chemical shift anisotropy (CSA) and a few different strategies to address this problem were discussed.
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Affiliation(s)
- Sungsool Wi
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32304, USA.
| | - Navneet Dwivedi
- Department of Advanced Spectroscopy and Imaging, Centre of Biomedical Research, SGPGIMS Campus, Raebarelly Road, Lucknow 226014, India; Department of Physics, Integral University, Lucknow 226026, India
| | - Richa Dubey
- Department of Advanced Spectroscopy and Imaging, Centre of Biomedical Research, SGPGIMS Campus, Raebarelly Road, Lucknow 226014, India
| | - Frederic Mentink-Vigier
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32304, USA
| | - Neeraj Sinha
- Department of Advanced Spectroscopy and Imaging, Centre of Biomedical Research, SGPGIMS Campus, Raebarelly Road, Lucknow 226014, India
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18
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Biedenbänder T, Aladin V, Saeidpour S, Corzilius B. Dynamic Nuclear Polarization for Sensitivity Enhancement in Biomolecular Solid-State NMR. Chem Rev 2022; 122:9738-9794. [PMID: 35099939 DOI: 10.1021/acs.chemrev.1c00776] [Citation(s) in RCA: 47] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Solid-state NMR with magic-angle spinning (MAS) is an important method in structural biology. While NMR can provide invaluable information about local geometry on an atomic scale even for large biomolecular assemblies lacking long-range order, it is often limited by low sensitivity due to small nuclear spin polarization in thermal equilibrium. Dynamic nuclear polarization (DNP) has evolved during the last decades to become a powerful method capable of increasing this sensitivity by two to three orders of magnitude, thereby reducing the valuable experimental time from weeks or months to just hours or days; in many cases, this allows experiments that would be otherwise completely unfeasible. In this review, we give an overview of the developments that have opened the field for DNP-enhanced biomolecular solid-state NMR including state-of-the-art applications at fast MAS and high magnetic field. We present DNP mechanisms, polarizing agents, and sample constitution methods suitable for biomolecules. A wide field of biomolecular NMR applications is covered including membrane proteins, amyloid fibrils, large biomolecular assemblies, and biomaterials. Finally, we present perspectives and recent developments that may shape the field of biomolecular DNP in the future.
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Affiliation(s)
- Thomas Biedenbänder
- Institute of Chemistry, University of Rostock, Albert-Einstein-Straße 3a, 18059 Rostock, Germany.,Department Life, Light & Matter, University of Rostock, Albert-Einstein-Straße 25, 18059 Rostock, Germany
| | - Victoria Aladin
- Institute of Chemistry, University of Rostock, Albert-Einstein-Straße 3a, 18059 Rostock, Germany.,Department Life, Light & Matter, University of Rostock, Albert-Einstein-Straße 25, 18059 Rostock, Germany
| | - Siavash Saeidpour
- Institute of Chemistry, University of Rostock, Albert-Einstein-Straße 3a, 18059 Rostock, Germany.,Department Life, Light & Matter, University of Rostock, Albert-Einstein-Straße 25, 18059 Rostock, Germany
| | - Björn Corzilius
- Institute of Chemistry, University of Rostock, Albert-Einstein-Straße 3a, 18059 Rostock, Germany.,Department Life, Light & Matter, University of Rostock, Albert-Einstein-Straße 25, 18059 Rostock, Germany
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19
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Menzildjian G, Lund A, Yulikov M, Gajan D, Niccoli L, Karthikeyan G, Casano G, Jeschke G, Ouari O, Lelli M, Lesage A. Efficient Dynamic Nuclear Polarization up to 230 K with Hybrid BDPA-Nitroxide Radicals at a High Magnetic Field. J Phys Chem B 2021; 125:13329-13338. [PMID: 34818009 DOI: 10.1021/acs.jpcb.1c07307] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Pairing the spectral resolution provided by high magnetic fields at ambient temperature with the enhanced sensitivity offered by dynamic nuclear polarization (DNP) is a major goal of modern solid-state NMR spectroscopy, which will allow one to unlock ever-challenging applications. This study demonstrates that, by combining HyTEK2, a hybrid BDPA-nitroxide biradical polarizing agent, with ortho-terphenyl (OTP), a rigid DNP matrix, enhancement factors as high as 65 can be obtained at 230 K, 40 kHz magic angle spinning (MAS), and 18.8 T. The temperature dependence of the DNP enhancement and its behavior around the glass transition temperature (Tg) of the matrix is investigated by variable-temperature EPR measurements of the electron relaxation properties and numerical simulations. A correlation is suggested between the decrease in enhancement at the passage of the Tg and the concomitant drop of both transverse electron relaxation times in the biradical.
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Affiliation(s)
- Georges Menzildjian
- Centre de RMN à Très Hauts Champs, Université de Lyon (CNRS/ENS Lyon/UCBL), 69100 Villeurbanne, France
| | - Alicia Lund
- Centre de RMN à Très Hauts Champs, Université de Lyon (CNRS/ENS Lyon/UCBL), 69100 Villeurbanne, France
| | - Maxim Yulikov
- Department of Chemistry and Applied Biosciences, Eidgenössische Technische Hochschule Zürich, CH-8093 Zürich, Switzerland
| | - David Gajan
- Centre de RMN à Très Hauts Champs, Université de Lyon (CNRS/ENS Lyon/UCBL), 69100 Villeurbanne, France
| | - Lorenzo Niccoli
- Center of Magnetic Resonance (CERM), University of Florence, 50019 Sesto Fiorentino, Italy
| | - Ganesan Karthikeyan
- Aix Marseille Univ, CNRS, Institut de Chimie Radicalaire, 13013 Marseille, France
| | - Gilles Casano
- Aix Marseille Univ, CNRS, Institut de Chimie Radicalaire, 13013 Marseille, France
| | - Gunnar Jeschke
- Department of Chemistry and Applied Biosciences, Eidgenössische Technische Hochschule Zürich, CH-8093 Zürich, Switzerland
| | - Olivier Ouari
- Aix Marseille Univ, CNRS, Institut de Chimie Radicalaire, 13013 Marseille, France
| | - Moreno Lelli
- Center of Magnetic Resonance (CERM), University of Florence, 50019 Sesto Fiorentino, Italy
| | - Anne Lesage
- Centre de RMN à Très Hauts Champs, Université de Lyon (CNRS/ENS Lyon/UCBL), 69100 Villeurbanne, France
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20
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Ghassemi N, Poulhazan A, Deligey F, Mentink-Vigier F, Marcotte I, Wang T. Solid-State NMR Investigations of Extracellular Matrixes and Cell Walls of Algae, Bacteria, Fungi, and Plants. Chem Rev 2021; 122:10036-10086. [PMID: 34878762 DOI: 10.1021/acs.chemrev.1c00669] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Extracellular matrixes (ECMs), such as the cell walls and biofilms, are important for supporting cell integrity and function and regulating intercellular communication. These biomaterials are also of significant interest to the production of biofuels and the development of antimicrobial treatment. Solid-state nuclear magnetic resonance (ssNMR) and magic-angle spinning-dynamic nuclear polarization (MAS-DNP) are uniquely powerful for understanding the conformational structure, dynamical characteristics, and supramolecular assemblies of carbohydrates and other biomolecules in ECMs. This review highlights the recent high-resolution investigations of intact ECMs and native cells in many organisms spanning across plants, bacteria, fungi, and algae. We spotlight the structural principles identified in ECMs, discuss the current technical limitation and underexplored biochemical topics, and point out the promising opportunities enabled by the recent advances of the rapidly evolving ssNMR technology.
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Affiliation(s)
- Nader Ghassemi
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Alexandre Poulhazan
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States.,Department of Chemistry, Université du Québec à Montréal, Montreal H2X 2J6, Canada
| | - Fabien Deligey
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | | | - Isabelle Marcotte
- Department of Chemistry, Université du Québec à Montréal, Montreal H2X 2J6, Canada
| | - Tuo Wang
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States
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21
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Mentink-Vigier F. Numerical recipes for faster MAS-DNP simulations. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2021; 333:107106. [PMID: 34837803 PMCID: PMC8639796 DOI: 10.1016/j.jmr.2021.107106] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 11/05/2021] [Accepted: 11/07/2021] [Indexed: 05/11/2023]
Abstract
Numerical simulations of Magic Angle Spinning Dynamic Nuclear Polarization (MAS-DNP) have transformed the way the DNP process is understood in rotating samples. In 2012, two methods were concomitantly developed to simulate small spin systems (< 4 spin-1/2). The development of new polarizing agents, including those containing metal centers with S > 1/2, makes it necessary to further expand the numerical tools with minimal approximations that will help rationalize the experimental observations and build approximate models. In this paper, three strategies developed in the past five years are presented: an adaptive integration scheme, a hybrid Hilbert/Liouville formalism, and a method to truncate the Liouville space basis for periodic Hamiltonian. Each of these methods enable time savings ranging from a factor of 3 to > 100. We illustrate the code performance by reporting for the first time the MAS-DNP field profiles for "AMUPol", in which the couplings to the nitrogen nuclei are explicitly considered, as well as Cross-Effect MAS-DNP field profiles with two electrons spin 5/2 interacting with a nuclear spin 1/2.
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Affiliation(s)
- Frederic Mentink-Vigier
- National High Magnetic Field Laboratory, Florida State University, 1800 E. Paul Dirac Dr, FL 32310, USA.
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22
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Korchak S, Kaltschnee L, Dervisoglu R, Andreas L, Griesinger C, Glöggler S. Spontaneous Enhancement of Magnetic Resonance Signals Using a RASER. Angew Chem Int Ed Engl 2021; 60:20984-20990. [PMID: 34289241 PMCID: PMC8518078 DOI: 10.1002/anie.202108306] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Indexed: 11/06/2022]
Abstract
Nuclear magnetic resonance is usually drastically limited by its intrinsically low sensitivity: Only a few spins contribute to the overall signal. To overcome this limitation, hyperpolarization methods were developed that increase signals several times beyond the normal/thermally polarized signals. The ideal case would be a universal approach that can signal enhance the complete sample of interest in solution to increase detection sensitivity. Here, we introduce a combination of para-hydrogen enhanced magnetic resonance with the phenomenon of the RASER: Large signals of para-hydrogen enhanced molecules interact with the magnetic resonance coil in a way that the signal is spontaneously converted into an in-phase signal. These molecules directly interact with other compounds via dipolar couplings and enhance their signal. We demonstrate that this is not only possible for solvent molecules but also for an amino acid.
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Affiliation(s)
- Sergey Korchak
- NMR Signal Enhancement GroupMax Planck Institute for Biophysical ChemistryAm Fassberg 1137077GöttingenGermany
- Center for Biostructural Imaging of Neurodegeneration of UMGVon-Siebold-Str. 3A37075GöttingenGermany
| | - Lukas Kaltschnee
- NMR Signal Enhancement GroupMax Planck Institute for Biophysical ChemistryAm Fassberg 1137077GöttingenGermany
- Center for Biostructural Imaging of Neurodegeneration of UMGVon-Siebold-Str. 3A37075GöttingenGermany
| | - Riza Dervisoglu
- Research Group for Solid State NMRMax Planck Institute for Biophysical ChemistryAm Fassberg 1137077GöttingenGermany
| | - Loren Andreas
- Research Group for Solid State NMRMax Planck Institute for Biophysical ChemistryAm Fassberg 1137077GöttingenGermany
| | - Christian Griesinger
- Department of NMR-based Structural BiologyMax Planck Institute for Biophysical ChemistryAm Fassberg 1137077GöttingenGermany
| | - Stefan Glöggler
- NMR Signal Enhancement GroupMax Planck Institute for Biophysical ChemistryAm Fassberg 1137077GöttingenGermany
- Center for Biostructural Imaging of Neurodegeneration of UMGVon-Siebold-Str. 3A37075GöttingenGermany
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23
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Korchak S, Kaltschnee L, Dervisoglu R, Andreas L, Griesinger C, Glöggler S. Spontaneous Enhancement of Magnetic Resonance Signals Using a RASER. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202108306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Sergey Korchak
- NMR Signal Enhancement Group Max Planck Institute for Biophysical Chemistry Am Fassberg 11 37077 Göttingen Germany
- Center for Biostructural Imaging of Neurodegeneration of UMG Von-Siebold-Str. 3A 37075 Göttingen Germany
| | - Lukas Kaltschnee
- NMR Signal Enhancement Group Max Planck Institute for Biophysical Chemistry Am Fassberg 11 37077 Göttingen Germany
- Center for Biostructural Imaging of Neurodegeneration of UMG Von-Siebold-Str. 3A 37075 Göttingen Germany
| | - Riza Dervisoglu
- Research Group for Solid State NMR Max Planck Institute for Biophysical Chemistry Am Fassberg 11 37077 Göttingen Germany
| | - Loren Andreas
- Research Group for Solid State NMR Max Planck Institute for Biophysical Chemistry Am Fassberg 11 37077 Göttingen Germany
| | - Christian Griesinger
- Department of NMR-based Structural Biology Max Planck Institute for Biophysical Chemistry Am Fassberg 11 37077 Göttingen Germany
| | - Stefan Glöggler
- NMR Signal Enhancement Group Max Planck Institute for Biophysical Chemistry Am Fassberg 11 37077 Göttingen Germany
- Center for Biostructural Imaging of Neurodegeneration of UMG Von-Siebold-Str. 3A 37075 Göttingen Germany
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24
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Nagashima H, Trébosc J, Kon Y, Lafon O, Amoureux JP. Efficient transfer of DNP-enhanced 1 H magnetization to half-integer quadrupolar nuclei in solids at moderate spinning rate. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2021; 59:920-939. [PMID: 33300128 DOI: 10.1002/mrc.5121] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 12/02/2020] [Accepted: 12/05/2020] [Indexed: 06/12/2023]
Abstract
We show herein how the proton magnetization enhanced by dynamic nuclear polarization (DNP) can be efficiently transferred at moderate magic-angle spinning (MAS) frequencies to half-integer quadrupolar nuclei, S ≥ 3/2, using the Dipolar-mediated Refocused Insensitive Nuclei Enhanced by Polarization Transfer (D-RINEPT) technique, in which a symmetry-based SR 4 1 2 recoupling scheme built from adiabatic inversion 1 H pulses reintroduces the 1 H-S dipolar couplings, while suppressing the 1 H-1 H ones. The use of adiabatic pulses also improves the robustness to offsets and radiofrequency (rf)-field inhomogeneity. Furthermore, the efficiency of the polarization transfer is further improved by using 1 H composite pulses and continuous-wave irradiations between the recoupling blocks, as well as by manipulating the S satellite transitions during the first recoupling block. Furthermore, in the case of large 1 H-S dipolar couplings, the D-RINEPT variant with two pulses on the quadrupolar channel results in an improved transfer efficiency. We compare here the performances of this new adiabatic scheme with those of its parent version with single π pulses, as well as with those of PRESTO and CPMAS transfers. This comparison is performed using simulations as well as DNP-enhanced 27 Al, 95 Mo, and 17 O NMR experiments on isotopically unmodified γ-alumina, hydrated titania-supported MoO3 , Mg(OH)2 , and l-histidine·HCl·H2 O. The introduced RINEPT method outperforms the existing methods, both in terms of efficiency and robustness to rf-field inhomogeneity and offset.
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Affiliation(s)
- Hiroki Nagashima
- Interdisciplinary Research Center for Catalytic Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
| | - Julien Trébosc
- Univ. Lille, CNRS, Centrale Lille, Univ. Artois, UMR 8181-UCCS-Unité de Catalyse et de Chimie du Solide, Lille, France
- Univ. Lille, CNRS, INRAE, Centrale Lille, Univ. Artois, FR 2638 - IMEC - Institut Michel-Eugène Chevreul, Lille, France
| | - Yoshihiro Kon
- Interdisciplinary Research Center for Catalytic Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
| | - Olivier Lafon
- Univ. Lille, CNRS, Centrale Lille, Univ. Artois, UMR 8181-UCCS-Unité de Catalyse et de Chimie du Solide, Lille, France
- Institut Universitaire de France, France
| | - Jean-Paul Amoureux
- Univ. Lille, CNRS, Centrale Lille, Univ. Artois, UMR 8181-UCCS-Unité de Catalyse et de Chimie du Solide, Lille, France
- Bruker BioSpin, Wissembourg, France
- NMR Science and Development Division, Riken, Yokohama, Japan
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25
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Mentink-Vigier F, Dubroca T, Van Tol J, Sigurdsson ST. The distance between g-tensors of nitroxide biradicals governs MAS-DNP performance: The case of the bTurea family. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2021; 329:107026. [PMID: 34246883 PMCID: PMC8316413 DOI: 10.1016/j.jmr.2021.107026] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Revised: 06/14/2021] [Accepted: 06/16/2021] [Indexed: 05/20/2023]
Abstract
Bis-nitroxide radicals are common polarizing agents (PA), used to enhance the sensitivity of solid-state NMR experiments via Magic Angle Spinning Dynamic Nuclear Polarization (MAS-DNP). These biradicals can increase the proton spin polarization through the Cross-Effect (CE) mechanism, which requires PAs with at least two unpaired electrons. The relative orientation of the bis-nitroxide moieties is critical to ensure efficient polarization transfer. Recently, we have defined a new quantity, the distance between g-tensors, that correlates the relative orientation of the nitroxides with the ability to polarize the surrounding nuclei. Here we analyse experimentally and theoretically a series of biradicals belonging to the bTurea family, namely bcTol, AMUPol and bcTol-M. They differ by the degree of substitution on the urea bridge that connects the two nitroxides. Using quantitative simulations developed for moderate MAS frequencies, we show that these modifications mostly affect the relative orientations of the nitroxide, i.e. the length and distribution of the distance between the g-tensors, that in turn impacts both the steady state nuclear polarization/depolarization as well as the build-up times. The doubly substituted urea bridge favours a large distance between the g-tensors, which enables bcTol-M to provide ∊on/off>200 at 14.1 T/600 MHz/395 GHz with build-up times of 3.8 s using a standard homogenous solution. The methodology described herein was used to show how the conformation of the spirocyclic rings flanking the nitroxide function in the recently described c- and o-HydrOPol affects the distance between the g-tensors and thereby polarization performance.
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Affiliation(s)
- Frédéric Mentink-Vigier
- National High Magnetic Field Laboratory, Florida State University, 1800 E. Paul Dirac Dr, Tallahassee, FL 32310, United States.
| | - Thierry Dubroca
- National High Magnetic Field Laboratory, Florida State University, 1800 E. Paul Dirac Dr, Tallahassee, FL 32310, United States
| | - Johan Van Tol
- National High Magnetic Field Laboratory, Florida State University, 1800 E. Paul Dirac Dr, Tallahassee, FL 32310, United States
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26
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Keller T, Maly T. Overhauser dynamic nuclear polarization (ODNP)-enhanced two-dimensional proton NMR spectroscopy at low magnetic fields. MAGNETIC RESONANCE (GOTTINGEN, GERMANY) 2021; 2:117-128. [PMID: 35465650 PMCID: PMC9030190 DOI: 10.5194/mr-2-117-2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 03/23/2021] [Indexed: 04/16/2023]
Abstract
The majority of low-field Overhauser dynamic nuclear polarization (ODNP) experiments reported so far have been 1D NMR experiments to study molecular dynamics and in particular hydration dynamics. In this work, we demonstrate the application of ODNP-enhanced 2D J-resolved (JRES) spectroscopy to improve spectral resolution beyond the limit imposed by the line broadening introduced by the paramagnetic polarizing agent. Using this approach, we are able to separate the overlapping multiplets of ethyl crotonate into a second dimension and clearly identify each chemical site individually. Crucial to these experiments is interleaved spectral referencing, a method introduced to compensate for temperature-induced field drifts over the course of the NMR acquisition. This method does not require additional hardware such as a field-frequency lock, which is especially challenging when designing compact systems.
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Affiliation(s)
- Timothy J. Keller
- Bridge12 Technologies Inc., 37 Loring Drive, Framingham, MA 01702, USA
| | - Thorsten Maly
- Bridge12 Technologies Inc., 37 Loring Drive, Framingham, MA 01702, USA
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27
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Stern Q, Cousin SF, Mentink-Vigier F, Pinon AC, Elliott SJ, Cala O, Jannin S. Direct observation of hyperpolarization breaking through the spin diffusion barrier. SCIENCE ADVANCES 2021; 7:7/18/eabf5735. [PMID: 33931450 PMCID: PMC8087418 DOI: 10.1126/sciadv.abf5735] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 03/11/2021] [Indexed: 05/02/2023]
Abstract
Dynamic nuclear polarization (DNP) is a widely used tool for overcoming the low intrinsic sensitivity of nuclear magnetic resonance spectroscopy and imaging. Its practical applicability is typically bounded, however, by the so-called "spin diffusion barrier," which relates to the poor efficiency of polarization transfer from highly polarized nuclei close to paramagnetic centers to bulk nuclei. A quantitative assessment of this barrier has been hindered so far by the lack of general methods for studying nuclear polarization flow in the vicinity of paramagnetic centers. Here, we fill this gap and introduce a general set of experiments based on microwave gating that are readily implemented. We demonstrate the versatility of our approach in experiments conducted between 1.2 and 4.2 K in static mode and at 100 K under magic angle spinning (MAS)-conditions typical for dissolution DNP and MAS-DNP-and directly observe the marked dependence of polarization flow on temperature.
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Affiliation(s)
- Quentin Stern
- Univ Lyon, CNRS, ENS Lyon, UCBL, Université de Lyon, CRMN UMR 5280, 69100 Villeurbanne, France.
| | - Samuel François Cousin
- Univ Lyon, CNRS, ENS Lyon, UCBL, Université de Lyon, CRMN UMR 5280, 69100 Villeurbanne, France
| | - Frédéric Mentink-Vigier
- National High Magnetic Field Laboratory, Florida State University, 1800 E. Paul Dirac Dr, Tallahassee, FL 32310, USA
| | | | - Stuart James Elliott
- Department of Chemistry, Crown Street, University of Liverpool, Liverpool L69 7ZD, UK
| | - Olivier Cala
- Univ Lyon, CNRS, ENS Lyon, UCBL, Université de Lyon, CRMN UMR 5280, 69100 Villeurbanne, France
| | - Sami Jannin
- Univ Lyon, CNRS, ENS Lyon, UCBL, Université de Lyon, CRMN UMR 5280, 69100 Villeurbanne, France
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28
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Deo T, Cheng Q, Paul S, Qiang W, Potapov A. Application of DNP-enhanced solid-state NMR to studies of amyloid-β peptide interaction with lipid membranes. Chem Phys Lipids 2021; 236:105071. [PMID: 33716023 DOI: 10.1016/j.chemphyslip.2021.105071] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 02/13/2021] [Accepted: 03/01/2021] [Indexed: 11/16/2022]
Abstract
The cellular membrane disruption induced by the aggregation of Aβ peptide has been proposed as a plausible cause of neuronal cell death during Alzheimer's disease. The molecular-level details of the Aβ interaction with cellular membranes were previously probed using solid state NMR (ssNMR), however, due to the limited sensitivity of the latter, studies were limited to samples with high Aβ-to-lipid ratio. The dynamic nuclear polarization (DNP) is a technique for increasing the sensitivity of NMR. In this work we demonstrate the feasibility of DNP-enhanced ssNMR studies of Aβ40 peptide interacting with various model liposomes: (1) a mixture of zwitterionic 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine (POPC) and negatively charged 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (POPG); (2) a mixture of POPC, POPG, cholesterol, sphingomyelin and ganglioside GM1; (3) the synaptic plasma membrane vesicles (SPMVs) extracted from rat brain tissues. In addition, DNP-ssNMR was applied to capturing changes in Aβ40 conformation taking place upon the peptide insertion into POPG liposomes. The signal enhancements under conditions of DNP allow carrying out informative 2D ssNMR experiments with about 0.25 mg of Aβ40 peptides (i.e. reaching Aβ40-to-lipid ratio of 1:200). In the studied liposome models, the 13C NMR chemical shifts at many 13C-labelled sites of Aβ40 are characteristic of β-sheets. In addition, in POPG liposomes the peptide forms hydrophobic contacts F19-L34 and F19-I32. Both the chemical shifts and hydrophobic contacts of Aβ40 in POPG remain the same before and after 8 h of incubation. This suggests that conformation at the 13C-labelled sites of the peptide is similar before and after the insertion process. Overall, our results demonstrate that DNP helps to overcome the sensitivity limitation of ssNMR, and thereby expand the applicability of ssNMR for charactering the Aβ peptide interacting with lipids.
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Affiliation(s)
- Thomas Deo
- School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Qinghui Cheng
- Department of Chemistry, Binghamton University, the State University of New York, Binghamton, NY, 13902, USA
| | - Subhadip Paul
- School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Wei Qiang
- Department of Chemistry, Binghamton University, the State University of New York, Binghamton, NY, 13902, USA
| | - Alexey Potapov
- School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK.
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29
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Keller TJ, Maly T. Overhauser dynamic nuclear polarization (ODNP)-enhanced two-dimensional proton NMR spectroscopy at low magnetic fields. MAGNETIC RESONANCE (GOTTINGEN, GERMANY) 2021. [PMID: 35465650 DOI: 10.5281/zenodo.4479048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 04/24/2023]
Abstract
The majority of low-field Overhauser dynamic nuclear polarization (ODNP) experiments reported so far have been 1D NMR experiments to study molecular dynamics and in particular hydration dynamics. In this work, we demonstrate the application of ODNP-enhanced 2D J-resolved (JRES) spectroscopy to improve spectral resolution beyond the limit imposed by the line broadening introduced by the paramagnetic polarizing agent. Using this approach, we are able to separate the overlapping multiplets of ethyl crotonate into a second dimension and clearly identify each chemical site individually. Crucial to these experiments is interleaved spectral referencing, a method introduced to compensate for temperature-induced field drifts over the course of the NMR acquisition. This method does not require additional hardware such as a field-frequency lock, which is especially challenging when designing compact systems.
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Affiliation(s)
- Timothy J Keller
- Bridge12 Technologies Inc., 37 Loring Drive, Framingham, MA 01702, USA
| | - Thorsten Maly
- Bridge12 Technologies Inc., 37 Loring Drive, Framingham, MA 01702, USA
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30
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Kumar A, Durand H, Zeno E, Balsollier C, Watbled B, Sillard C, Fort S, Baussanne I, Belgacem N, Lee D, Hediger S, Demeunynck M, Bras J, De Paëpe G. The surface chemistry of a nanocellulose drug carrier unravelled by MAS-DNP. Chem Sci 2020; 11:3868-3877. [PMID: 34122855 PMCID: PMC8152408 DOI: 10.1039/c9sc06312a] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Cellulose nanofibrils (CNF) are renewable bio-based materials with high specific area, which makes them ideal candidates for multiple emerging applications including for instance on-demand drug release. However, in-depth chemical and structural characterization of the CNF surface chemistry is still an open challenge, especially for low weight percentage of functionalization. This currently prevents the development of efficient, cost-effective and reproducible green synthetic routes and thus the widespread development of targeted and responsive drug-delivery CNF carriers. We show in this work how we use dynamic nuclear polarization (DNP) to overcome the sensitivity limitation of conventional solid-state NMR and gain insight into the surface chemistry of drug-functionalized TEMPO-oxidized cellulose nanofibrils. The DNP enhanced-NMR data can report unambiguously on the presence of trace amounts of TEMPO moieties and depolymerized cellulosic units in the starting material, as well as coupling agents on the CNFs surface (used in the heterogeneous reaction). This enables a precise estimation of the drug loading while differentiating adsorption from covalent bonding (∼1 wt% in our case) as opposed to other analytical techniques such as elemental analysis and conductometric titration that can neither detect the presence of coupling agents, nor differentiate unambiguously between adsorption and grafting. The approach, which does not rely on the use of 13C/15N enriched compounds, will be key to further develop efficient surface chemistry routes and has direct implication for the development of drug delivery applications both in terms of safety and dosage. DNP-enhanced solid-state NMR unravels the surface chemistry of functionalized nanocellulose.![]()
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Affiliation(s)
- Akshay Kumar
- Univ. Grenoble Alpes, CEA, CNRS, IRIG-MEM Grenoble France
| | | | - Elisa Zeno
- Centre Technique du Papier (CTP) Grenoble France
| | - Cyril Balsollier
- Univ. Grenoble Alpes, CNRS, CERMAV Grenoble France.,Univ. Grenoble Alpes, CNRS, DPM Grenoble France
| | | | - Cecile Sillard
- Univ. Grenoble Alpes, CNRS, Grenoble-INP, LGP2 Grenoble France
| | | | | | - Naceur Belgacem
- Univ. Grenoble Alpes, CNRS, Grenoble-INP, LGP2 Grenoble France
| | - Daniel Lee
- Univ. Grenoble Alpes, CEA, CNRS, IRIG-MEM Grenoble France
| | - Sabine Hediger
- Univ. Grenoble Alpes, CEA, CNRS, IRIG-MEM Grenoble France
| | | | - Julien Bras
- Univ. Grenoble Alpes, CNRS, Grenoble-INP, LGP2 Grenoble France
| | - Gaël De Paëpe
- Univ. Grenoble Alpes, CEA, CNRS, IRIG-MEM Grenoble France
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31
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Park H, Uluca-Yazgi B, Heumann S, Schlögl R, Granwehr J, Heise H, Schleker PPM. Heteronuclear cross-relaxation effect modulated by the dynamics of N-functional groups in the solid state under 15N DP-MAS DNP. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2020; 312:106688. [PMID: 32004819 DOI: 10.1016/j.jmr.2020.106688] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 01/12/2020] [Accepted: 01/14/2020] [Indexed: 06/10/2023]
Abstract
In a typical magic-angle spinning (MAS) dynamic nuclear polarization (DNP) nuclear magnetic resonance (NMR) experiment, several mechanisms are simultaneously involved when transferring much larger polarization of electron spins to NMR active nuclei of interest. Recently, specific cross-relaxation enhancement by active motions under DNP (SCREAM-DNP) [Daube et al. JACS 2016] has been reported as one of these mechanisms. Thereby 13C enhancement with inverted sign was observed in a direct polarization (DP) MAS DNP experiment, caused by reorientation dynamics of methyl that was not frozen out at 100 K. Here, we report on the spontaneous polarization transfer from hyperpolarized 1H to both primary amine and ammonium nitrogens, resulting in an additional positive signal enhancement in the 15N NMR spectra during 15N DP-MAS DNP. The cross-relaxation induced signal enhancement (CRE) for 15N is of opposite sign compared to that observed for 13C due to the negative sign of the gyromagnetic ratio of 15N. The influence on CRE efficiency caused by variation of the radical solution composition and by temperature was also investigated.
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Affiliation(s)
- Heeyong Park
- Max Planck Institute for Chemical Energy Conversion, Department of Heterogeneous Reactions, 45470 Mülheim an der Ruhr, Germany; Forschungszentrum Jülich, IEK-9, 52425 Jülich, Germany; RWTH Aachen University, Institute of Technical and Macromolecular Chemistry, 52074 Aachen, Germany
| | - Boran Uluca-Yazgi
- Forschungszentrum Jülich, IBI-7 and JuStruct, 52425 Jülich, Germany; Heinrich Heine Universität Düsseldorf, Institute of Physical Biology, 40225 Düsseldorf, Germany
| | - Saskia Heumann
- Max Planck Institute for Chemical Energy Conversion, Department of Heterogeneous Reactions, 45470 Mülheim an der Ruhr, Germany
| | - Robert Schlögl
- Max Planck Institute for Chemical Energy Conversion, Department of Heterogeneous Reactions, 45470 Mülheim an der Ruhr, Germany; Fritz Haber Institute of the Max Planck Society, 14195 Berlin, Germany
| | - Josef Granwehr
- Forschungszentrum Jülich, IEK-9, 52425 Jülich, Germany; RWTH Aachen University, Institute of Technical and Macromolecular Chemistry, 52074 Aachen, Germany
| | - Henrike Heise
- Forschungszentrum Jülich, IBI-7 and JuStruct, 52425 Jülich, Germany; Heinrich Heine Universität Düsseldorf, Institute of Physical Biology, 40225 Düsseldorf, Germany
| | - P Philipp M Schleker
- Max Planck Institute for Chemical Energy Conversion, Department of Heterogeneous Reactions, 45470 Mülheim an der Ruhr, Germany; Forschungszentrum Jülich, IEK-9, 52425 Jülich, Germany.
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32
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Mandal S, Sigurdsson ST. Water-soluble BDPA radicals with improved persistence. Chem Commun (Camb) 2020; 56:13121-13124. [DOI: 10.1039/d0cc04920d] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
1,3-Bis(diphenylene)-2-phenylallyl (BDPA) radicals are promising polarizing agents for dynamic nuclear polarization (DNP) NMR spectroscopy. BDPAs containing tetraalkyl/aryl-ammonium groups have increased persistence and solubility in polar solvents.
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Affiliation(s)
- Sucharita Mandal
- University of Iceland
- Department of Chemistry
- Science Institute
- Reykjavik 107
- Iceland
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33
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Kaminker I. Recent Advances in Magic Angle Spinning‐Dynamic Nuclear Polarization Methodology. Isr J Chem 2019. [DOI: 10.1002/ijch.201900092] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Ilia Kaminker
- School of ChemistryTel Aviv University Ramat Aviv 6997801 Tel Aviv Israel
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34
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Reese M, George C, Yang C, Jawla S, Grün JT, Schwalbe H, Redfield C, Temkin RJ, Griffin RG. Modular, triple-resonance, transmission line DNP MAS probe for 500 MHz/330 GHz. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2019; 307:106573. [PMID: 31505305 PMCID: PMC6766420 DOI: 10.1016/j.jmr.2019.106573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 08/12/2019] [Accepted: 08/13/2019] [Indexed: 06/10/2023]
Abstract
We describe the design and construction of a modular, triple-resonance, fully balanced, DNP-MAS probe based on transmission line technology and its integration into a 500 MHz/330 GHz DNP-NMR spectrometer. A novel quantitative probe design and characterization strategy is developed and employed to achieve optimal sensitivity, RF homogeneity and excellent isolation between channels. The resulting three channel HCN probe has a modular design with each individual, swappable module being equipped with connectorized, transmission line ports. This strategy permits attachment of a mating connector that facilitates accurate impedance measurements at these ports and allows characterization and adjustment (e.g. for balancing or tuning/matching) of each component individually. The RF performance of the probe is excellent; for example, the 13C channel attains a Rabi frequency of 280 kHz for a 3.2 mm rotor. In addition, a frequency tunable 330 GHz gyrotron operating at the second harmonic of the electron cyclotron frequency was developed for DNP applications. Careful alignment of the corrugated waveguide led to minimal loss of the microwave power, and an enhancement factor ε = 180 was achieved for U-13C urea in the glassy matrix at 80 K. We demonstrated the operation of the system with acquisition of multidimensional spectra of cross-linked lysozyme crystals which are insoluble in glycerol-water mixtures used for DNP and samples of RNA.
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Affiliation(s)
- Marcel Reese
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Christy George
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Chen Yang
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Sudheer Jawla
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - J Tassilo Grün
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Johann Wolfgang Goethe-Universität Frankfurt, 60438 Frankfurt, Germany
| | - Harald Schwalbe
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Johann Wolfgang Goethe-Universität Frankfurt, 60438 Frankfurt, Germany
| | - Christina Redfield
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Richard J Temkin
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Robert G Griffin
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, United States.
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35
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Rankin AGM, Trébosc J, Pourpoint F, Amoureux JP, Lafon O. Recent developments in MAS DNP-NMR of materials. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2019; 101:116-143. [PMID: 31189121 DOI: 10.1016/j.ssnmr.2019.05.009] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 05/21/2019] [Accepted: 05/21/2019] [Indexed: 05/03/2023]
Abstract
Solid-state NMR spectroscopy is a powerful technique for the characterization of the atomic-level structure and dynamics of materials. Nevertheless, the use of this technique is often limited by its lack of sensitivity, which can prevent the observation of surfaces, defects or insensitive isotopes. Dynamic Nuclear Polarization (DNP) has been shown to improve by one to three orders of magnitude the sensitivity of NMR experiments on materials under Magic-Angle Spinning (MAS), at static magnetic field B0 ≥ 5 T, conditions allowing for the acquisition of high-resolution spectra. The field of DNP-NMR spectroscopy of materials has undergone a rapid development in the last ten years, spurred notably by the availability of commercial DNP-NMR systems. We provide here an in-depth overview of MAS DNP-NMR studies of materials at high B0 field. After a historical perspective of DNP of materials, we describe the DNP transfers under MAS, the transport of polarization by spin diffusion and the various contributions to the overall sensitivity of DNP-NMR experiments. We discuss the design of tailored polarizing agents and the sample preparation in the case of materials. We present the DNP-NMR hardware and the influence of key experimental parameters, such as microwave power, magnetic field, temperature and MAS frequency. We give an overview of the isotopes that have been detected by this technique, and the NMR methods that have been combined with DNP. Finally, we show how MAS DNP-NMR has been applied to gain new insights into the structure of organic, hybrid and inorganic materials with applications in fields, such as health, energy, catalysis, optoelectronics etc.
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Affiliation(s)
- Andrew G M Rankin
- Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181, UCCS, Unité de Catalyse et Chimie du Solide, F-59000, Lille, France
| | - Julien Trébosc
- Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181, UCCS, Unité de Catalyse et Chimie du Solide, F-59000, Lille, France; Univ. Lille, CNRS-FR2638, Fédération Chevreul, F-59000 Lille, France
| | - Frédérique Pourpoint
- Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181, UCCS, Unité de Catalyse et Chimie du Solide, F-59000, Lille, France
| | - Jean-Paul Amoureux
- Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181, UCCS, Unité de Catalyse et Chimie du Solide, F-59000, Lille, France; Bruker Biospin, 34 rue de l'industrie, F-67166, Wissembourg, France
| | - Olivier Lafon
- Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181, UCCS, Unité de Catalyse et Chimie du Solide, F-59000, Lille, France; Institut Universitaire de France, 1 rue Descartes, F-75231, Paris, France.
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36
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Smith AN, Märker K, Hediger S, De Paëpe G. Natural Isotopic Abundance 13C and 15N Multidimensional Solid-State NMR Enabled by Dynamic Nuclear Polarization. J Phys Chem Lett 2019; 10:4652-4662. [PMID: 31361489 DOI: 10.1021/acs.jpclett.8b03874] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Dynamic nuclear polarization (DNP) has made feasible solid-state NMR experiments that were previously thought impractical due to sensitivity limitations. One such class of experiments is the structural characterization of organic and biological samples at natural isotopic abundance (NA). Herein, we describe the many advantages of DNP-enabled ssNMR at NA, including the extraction of long-range distance constraints using dipolar recoupling pulse sequences without the deleterious effects of dipolar truncation. In addition to the theoretical underpinnings in the analysis of these types of experiments, numerous applications of DNP-enabled ssNMR at NA are discussed.
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Affiliation(s)
- Adam N Smith
- Univ. Grenoble Alpes, CEA, CNRS, IRIG, MEM , F-38000 Grenoble , France
| | - Katharina Märker
- Univ. Grenoble Alpes, CEA, CNRS, IRIG, MEM , F-38000 Grenoble , France
| | - Sabine Hediger
- Univ. Grenoble Alpes, CEA, CNRS, IRIG, MEM , F-38000 Grenoble , France
| | - Gaël De Paëpe
- Univ. Grenoble Alpes, CEA, CNRS, IRIG, MEM , F-38000 Grenoble , France
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37
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Albannay MM, Vinther JMO, Capozzi A, Zhurbenko V, Ardenkjaer-Larsen JH. Optimized microwave delivery in dDNP. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2019; 305:58-65. [PMID: 31220776 DOI: 10.1016/j.jmr.2019.06.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 06/09/2019] [Accepted: 06/10/2019] [Indexed: 06/09/2023]
Abstract
Dissolution dynamic nuclear polarization (dDNP) has permitted the production of highly polarized liquid-state samples, enabling real-time imaging of metabolic processes non-invasively in vivo. The desire for higher magnetic resonance sensitivity has led to the development of multiple home-built and commercial dDNP polarizers employing solid-state microwave sources. Providing efficient microwave delivery that avoids unwanted heating of the sample is a crucial step to achieve high nuclear polarization. Consequently, a process is described to reduce waveguide attenuation due to resistive loss thereby doubling the delivered power. A mirror and reflector are designed and tested to increase the microwave field density across the sample volume resulting in a 2.3 dB increase of delivered power. Thermal considerations with regards to waveguide geometry and dDNP probe design are discussed. A thermal model of the dDNP probe is computed and experimentally verified.
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Affiliation(s)
- Mohammed M Albannay
- Center for Hyperpolarization in Magnetic Resonance, Magnetic Resonance, Department of Health Technology, Technical University of Denmark, Ørsteds Plads, 2800 Kgs. Lyngby, Denmark
| | - Joachim M O Vinther
- Center for Hyperpolarization in Magnetic Resonance, Magnetic Resonance, Department of Health Technology, Technical University of Denmark, Ørsteds Plads, 2800 Kgs. Lyngby, Denmark
| | - Andrea Capozzi
- Center for Hyperpolarization in Magnetic Resonance, Magnetic Resonance, Department of Health Technology, Technical University of Denmark, Ørsteds Plads, 2800 Kgs. Lyngby, Denmark
| | - Vitaliy Zhurbenko
- Center for Hyperpolarization in Magnetic Resonance, Magnetic Resonance, Department of Health Technology, Technical University of Denmark, Ørsteds Plads, 2800 Kgs. Lyngby, Denmark
| | - Jan Henrik Ardenkjaer-Larsen
- Center for Hyperpolarization in Magnetic Resonance, Magnetic Resonance, Department of Health Technology, Technical University of Denmark, Ørsteds Plads, 2800 Kgs. Lyngby, Denmark; GE Healthcare, Brøndby, Denmark.
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38
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Salnikov ES, Aussenac F, Abel S, Purea A, Tordo P, Ouari O, Bechinger B. Dynamic Nuclear Polarization / solid-state NMR of membranes. Thermal effects and sample geometry. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2019; 100:70-76. [PMID: 30995597 DOI: 10.1016/j.ssnmr.2019.03.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 03/18/2019] [Accepted: 03/18/2019] [Indexed: 06/09/2023]
Abstract
Whereas specially designed dinitroxide biradicals, reconstitution protocols, oriented sample geometries and NMR probes have helped to much increase the DNP enhancement factors of membrane samples they still lag considerably behind those obtained from glasses made of protein solutions. Here we show that not only the MAS rotor material but also the distribution of the membrane samples within the NMR rotor have a pronounced effect on the DNP enhancement. These observations are rationalized with the cooling efficiency and the internal properties of the sample, monitored by their T1 relaxation, microwave ON versus OFF signal intensities and DNP effect. The data are suggestive that for membranes the speed of cooling has a pronounced effect on the membrane properties and concomitantly the distribution of biradicals within the sample.
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Affiliation(s)
| | | | - Sebastian Abel
- Aix-Marseille University, CNRS, UMR 7273, Institut de Chimie Radicalaire, 13013, Marseille, France
| | | | - Paul Tordo
- Aix-Marseille University, CNRS, UMR 7273, Institut de Chimie Radicalaire, 13013, Marseille, France
| | - Olivier Ouari
- Aix-Marseille University, CNRS, UMR 7273, Institut de Chimie Radicalaire, 13013, Marseille, France
| | - Burkhard Bechinger
- Institute of Chemistry, University of Strasbourg / CNRS, UMR7177, 67070, Strasbourg, France.
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39
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Sergeyev IV, Aussenac F, Purea A, Reiter C, Bryerton E, Retzloff S, Hesler J, Tometich L, Rosay M. Efficient 263 GHz magic angle spinning DNP at 100 K using solid-state diode sources. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2019; 100:63-69. [PMID: 30965254 DOI: 10.1016/j.ssnmr.2019.03.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 03/22/2019] [Accepted: 03/26/2019] [Indexed: 05/03/2023]
Abstract
The development of new, high-frequency solid-state diode sources capable of operating at 263 GHz, together with an optimized stator design for improved millimeter-wave coupling to the NMR sample, have enabled low-power DNP experiments at 263 GHz/400 MHz. With 250 mW output power, signal enhancements as high as 120 are achieved on standard samples - approximately 1/3 of the maximal enhancement available with high-power gyrotrons under similar conditions. Diode-based sources have a number of advantages over vacuum tube devices: they emit a pure mode, can be rapidly frequency-swept over a wide range of frequencies, have reproducible output power over this range, and have excellent output stability. By virtue of their small size, low thermal footprint, and lack of facility requirements, solid-state diodes are also considerably cheaper to operate and maintain than high-power vacuum tube devices. In light of these features, and anticipating further improvements in terms of available output power, solid-state diodes are likely to find widespread use in DNP and contribute to further advances in the field.
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Affiliation(s)
- Ivan V Sergeyev
- Bruker BioSpin Corp., 15 Fortune Drive, Billerica, MA, 01821, USA.
| | - Fabien Aussenac
- Bruker France S.A.S., 34 Rue de l'Industrie, 67160, Wissembourg, France
| | - Armin Purea
- Bruker BioSpin GmbH, Silberstreifen 4, 76287, Rheinstetten, Germany
| | - Christian Reiter
- Bruker BioSpin GmbH, Silberstreifen 4, 76287, Rheinstetten, Germany
| | - Eric Bryerton
- Virginia Diodes Inc., 979 2(nd) St. SE, Charlottesville, VA, 22902, USA
| | - Steven Retzloff
- Virginia Diodes Inc., 979 2(nd) St. SE, Charlottesville, VA, 22902, USA
| | - Jeffrey Hesler
- Virginia Diodes Inc., 979 2(nd) St. SE, Charlottesville, VA, 22902, USA
| | - Leo Tometich
- Bruker BioSpin Corp., 15 Fortune Drive, Billerica, MA, 01821, USA
| | - Melanie Rosay
- Bruker BioSpin Corp., 15 Fortune Drive, Billerica, MA, 01821, USA
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40
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Thureau P, Juramy M, Ziarelli F, Viel S, Mollica G. Brute-force solvent suppression for DNP studies of powders at natural isotopic abundance. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2019; 99:15-19. [PMID: 30836289 DOI: 10.1016/j.ssnmr.2019.02.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 02/15/2019] [Accepted: 02/15/2019] [Indexed: 06/09/2023]
Abstract
A method based on highly concentrated radical solutions is investigated for the suppression of the NMR signals arising from solvents that are usually used for dynamic nuclear polarization experiments. The presented method is suitable in the case of powders, which are impregnated with a radical-containing solution. It is also demonstrated that the intensity and the resolution of the signals due to the sample of interest is not affected by the high concentration of radicals. The method proposed here is therefore valuable when sensitivity is of the utmost importance, namely samples at natural isotopic abundance.
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Affiliation(s)
| | - Marie Juramy
- Aix Marseille Univ, CNRS, ICR, Marseille, France
| | - Fabio Ziarelli
- Aix Marseille Univ, CNRS, Centrale Marseille, FSCM, Marseille, France
| | - Stephane Viel
- Aix Marseille Univ, CNRS, ICR, Marseille, France; Institut Universitaire de France, Paris, France
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41
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Aladin V, Corzilius B. Methyl dynamics in amino acids modulate heteronuclear cross relaxation in the solid state under MAS DNP. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2019; 99:27-35. [PMID: 30865870 DOI: 10.1016/j.ssnmr.2019.02.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 02/20/2019] [Accepted: 02/20/2019] [Indexed: 05/09/2023]
Abstract
Dynamic Nuclear Polarization (DNP) is a wide-spread technique for sensitivity enhancement of MAS NMR. During a typical MAS DNP experiment, several mechanisms resulting in polarization transfer may be active at the same time. One such mechanism which is most commonly active but up to now mostly disregarded is SCREAM-DNP (Specific Cross Relaxation Enhancement by Active Motions under DNP). This effect is generally observed in direct DNP experiments if molecular dynamics are supporting heteronuclear cross relaxation similar to the nuclear Overhauser effect. We investigate this effect for the CH3 groups of all methyl-bearing amino acids (i.e., alanine, valine, leucine, isoleucine, threonine, and methionine). At the typical DNP temperature of ∼110 K the three-fold reorientation dynamics are still active, and efficient SCREAM-DNP is observed. We discuss variations in enhancement factors obtained by this effect in context of sample temperature and sterical hindrance of the methyl group. Next to the direct transfer to the methyl carbon, we also find evidence for much weaker transfer from the methyl protons directly to other carbons in the amino acid molecule and succeed to correlate build-up dynamics with the CH dipole coupling which is modulated by the CH3 orientation. Besides methyl dynamics we also identify ring dynamics within proline as a source of SCREAM-DNP. Our results are the first step towards utilization of this effect as a specific probing techniqueusing methyl groups in protein systems.
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Affiliation(s)
- Victoria Aladin
- Institute of Physical Chemistry, Institute of Biophysical Chemistry, Biomolecular Magnetic Resonance Center (BMRZ), Goethe University Frankfurt, Max-von-Laue-Str. 7-9, 60438, Frankfurt, Germany
| | - Björn Corzilius
- Institute of Physical Chemistry, Institute of Biophysical Chemistry, Biomolecular Magnetic Resonance Center (BMRZ), Goethe University Frankfurt, Max-von-Laue-Str. 7-9, 60438, Frankfurt, Germany.
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42
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Brownbill NJ, Lee D, De Paëpe G, Blanc F. Detection of the Surface of Crystalline Y 2O 3 Using Direct 89Y Dynamic Nuclear Polarization. J Phys Chem Lett 2019; 10:3501-3508. [PMID: 31150249 PMCID: PMC6589743 DOI: 10.1021/acs.jpclett.9b01185] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 05/31/2019] [Indexed: 05/29/2023]
Abstract
Nuclei with low gyromagnetic ratio (γ) present a serious sensitivity challenge for nulear magnetic resonance (NMR) spectroscopy. Recently, dynamic nuclear polarization (DNP) has shown great promise in overcoming this hurdle by indirect hyperpolarization (via 1H) of these low-γ nuclei. Here we show that at a magnetic field of 9.4 T and cryogenic temperature of about 110 K direct DNP of 89Y in a frozen solution of Y(NO3)3 can offer signal enhancements greater than 80 times using exogeneous trityl OX063 monoradical by satisfying the cross effect magic angle spinning (MAS) DNP mechanism. The large signal enhancement achieved permits 89Y NMR spectra of Y2O3 and Gd2O3-added Y2O3 materials to be obtained quickly (∼30 min), revealing a range of surface yttrium hydroxyl groups in addition to the two octahedral yttrium signals of the core. The results open up promises for the observation of low gyromagnetic ratio nuclei and the detection of corresponding surface and (sub-)surface sites.
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Affiliation(s)
- Nick J. Brownbill
- Department
of Chemistry, University of Liverpool, Crown Street, Liverpool L69 7ZD, United
Kingdom
| | - Daniel Lee
- Univ.
Grenoble Alpes, CEA, IRIG, MEM, F-38000 Grenoble, France
| | - Gaël De Paëpe
- Univ.
Grenoble Alpes, CEA, IRIG, MEM, F-38000 Grenoble, France
| | - Frédéric Blanc
- Department
of Chemistry, University of Liverpool, Crown Street, Liverpool L69 7ZD, United
Kingdom
- Stephenson
Institute for Renewable Energy, University
of Liverpool, Crown Street, Liverpool L69 7ZF, United Kingdom
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43
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Purea A, Reiter C, Dimitriadis AI, de Rijk E, Aussenac F, Sergeyev I, Rosay M, Engelke F. Improved waveguide coupling for 1.3 mm MAS DNP probes at 263 GHz. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2019; 302:43-49. [PMID: 30953925 DOI: 10.1016/j.jmr.2019.03.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 03/26/2019] [Accepted: 03/27/2019] [Indexed: 06/09/2023]
Abstract
We consider the geometry of a radially irradiated microwave beam in MAS DNP NMR probes and its impact on DNP enhancement. Two related characteristic features are found to be relevant: (i) the focus of the microwave beam on the DNP MAS sample and (ii) the microwave magnetic field magnitude in the sample. We present a waveguide coupler setup that enables us to significantly improve beam focus and field magnitude in 1.3 mm MAS DNP probes at a microwave frequency of 263 GHz, which results in an increase of the DNP enhancement by a factor of 2 compared to previous standard hardware setups. We discuss the implications of improved coupling and its potential to enable cutting-edge applications, such as pulsed high-field DNP and the use of low-power solid-state microwave sources.
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44
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König A, Schölzel D, Uluca B, Viennet T, Akbey Ü, Heise H. Hyperpolarized MAS NMR of unfolded and misfolded proteins. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2019; 98:1-11. [PMID: 30641444 DOI: 10.1016/j.ssnmr.2018.12.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 12/28/2018] [Accepted: 12/30/2018] [Indexed: 05/09/2023]
Abstract
In this article we give an overview over the use of DNP-enhanced solid-state NMR spectroscopy for the investigation of unfolded, disordered and misfolded proteins. We first provide an overview over studies in which DNP spectroscopy has successfully been applied for the structural investigation of well-folded amyloid fibrils formed by short peptides as well as full-length proteins. Sample cooling to cryogenic temperatures often leads to severe line broadening of resonance signals and thus a loss in resolution. However, inhomogeneous line broadening at low temperatures provides valuable information about residual dynamics and flexibility in proteins, and, in combination with appropriate selective isotope labeling techniques, inhomogeneous linewidths in disordered proteins or protein regions may be exploited for evaluation of conformational ensembles. In the last paragraph we highlight some recent studies where DNP-enhanced MAS-NMR-spectroscopy was applied to the study of disordered proteins/protein regions and inhomogeneous sample preparations.
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Affiliation(s)
- Anna König
- Institute of Complex Systems, Structural Biochemistry (ICS-6), Research Center Jülich, 52425, Jülich, Germany; Institute of Physical Biology, Heinrich-Heine-University Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Daniel Schölzel
- Institute of Complex Systems, Structural Biochemistry (ICS-6), Research Center Jülich, 52425, Jülich, Germany; Institute of Physical Biology, Heinrich-Heine-University Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Boran Uluca
- Institute of Complex Systems, Structural Biochemistry (ICS-6), Research Center Jülich, 52425, Jülich, Germany; Institute of Physical Biology, Heinrich-Heine-University Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Thibault Viennet
- Institute of Complex Systems, Structural Biochemistry (ICS-6), Research Center Jülich, 52425, Jülich, Germany; Institute of Physical Biology, Heinrich-Heine-University Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Ümit Akbey
- Institute of Complex Systems, Structural Biochemistry (ICS-6), Research Center Jülich, 52425, Jülich, Germany; Institute of Physical Biology, Heinrich-Heine-University Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Henrike Heise
- Institute of Complex Systems, Structural Biochemistry (ICS-6), Research Center Jülich, 52425, Jülich, Germany; Institute of Physical Biology, Heinrich-Heine-University Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany.
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45
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Demers JP, Fricke P, Shi C, Chevelkov V, Lange A. Structure determination of supra-molecular assemblies by solid-state NMR: Practical considerations. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2018; 109:51-78. [PMID: 30527136 DOI: 10.1016/j.pnmrs.2018.06.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 06/15/2018] [Accepted: 06/15/2018] [Indexed: 05/26/2023]
Abstract
In the cellular environment, biomolecules assemble in large complexes which can act as molecular machines. Determining the structure of intact assemblies can reveal conformations and inter-molecular interactions that are only present in the context of the full assembly. Solid-state NMR (ssNMR) spectroscopy is a technique suitable for the study of samples with high molecular weight that allows the atomic structure determination of such large protein assemblies under nearly physiological conditions. This review provides a practical guide for the first steps of studying biological supra-molecular assemblies using ssNMR. The production of isotope-labeled samples is achievable via several means, which include recombinant expression, cell-free protein synthesis, extraction of assemblies directly from cells, or even the study of assemblies in whole cells in situ. Specialized isotope labeling schemes greatly facilitate the assignment of chemical shifts and the collection of structural data. Advanced strategies such as mixed, diluted, or segmental subunit labeling offer the possibility to study inter-molecular interfaces. Detailed and practical considerations are presented with respect to first setting up magic-angle spinning (MAS) ssNMR experiments, including the selection of the ssNMR rotor, different methods to best transfer the sample and prepare the rotor, as well as common and robust procedures for the calibration of the instrument. Diagnostic spectra to evaluate the resolution and sensitivity of the sample are presented. Possible improvements that can reduce sample heterogeneity and improve the quality of ssNMR spectra are reviewed.
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Affiliation(s)
- Jean-Philippe Demers
- Department of Molecular Biophysics, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany; Laboratory of Cell Biology, Center for Cancer Research (CCR), National Cancer Institute (NCI), National Institutes of Health (NIH), Bethesda, MD 20892, USA
| | - Pascal Fricke
- Department of Molecular Biophysics, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | - Chaowei Shi
- Department of Molecular Biophysics, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | - Veniamin Chevelkov
- Department of Molecular Biophysics, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | - Adam Lange
- Department of Molecular Biophysics, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany; Institut für Biologie, Humboldt-Universität zu Berlin, 10115 Berlin, Germany.
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46
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Scott FJ, Alaniva N, Golota NC, Sesti EL, Saliba EP, Price LE, Albert BJ, Chen P, O'Connor RD, Barnes AB. A versatile custom cryostat for dynamic nuclear polarization supports multiple cryogenic magic angle spinning transmission line probes. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 297:23-32. [PMID: 30342370 DOI: 10.1016/j.jmr.2018.10.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 09/29/2018] [Accepted: 10/02/2018] [Indexed: 06/08/2023]
Abstract
Dynamic nuclear polarization (DNP) with cryogenic magic angle spinning (MAS) provides significant improvements in NMR sensitivity, yet presents unique technical challenges. Here we describe a custom cryostat and suite of NMR probes capable of manipulating nuclear spins with multi-resonant radiofrequency circuits, cryogenic spinning below 6 K, sample exchange, and microwave coupling for DNP. The corrugated waveguide and six transfer lines needed for DNP and cryogenic spinning functionality are coupled to the probe from the top of the magnet. Transfer lines are vacuum-jacketed and provide bearing and drive gas, variable temperature fluid, two exhaust pathways, and a sample ejection port. The cryostat thermally isolates the magnet bore, thereby protecting the magnet and increasing cryogen efficiency. This novel design supports cryogenic MAS-DNP performance over an array of probes without altering DNP functionality. We present three MAS probes (two supporting 3.2 mm rotors and one supporting 9.5 mm rotors) interfacing with the single cryostat. Mechanical details, transmission line radio frequency design, and performance of the cryostat and three probes are described.
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Affiliation(s)
- Faith J Scott
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Nicholas Alaniva
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Natalie C Golota
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Erika L Sesti
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Edward P Saliba
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Lauren E Price
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Brice J Albert
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Pinhui Chen
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA; Department of Physics, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Robert D O'Connor
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA
| | - Alexander B Barnes
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA.
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47
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Martin RW, Kelly JE, Kelz JI. Advances in instrumentation and methodology for solid-state NMR of biological assemblies. J Struct Biol 2018; 206:73-89. [PMID: 30205196 DOI: 10.1016/j.jsb.2018.09.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 07/08/2018] [Accepted: 09/06/2018] [Indexed: 01/11/2023]
Abstract
Many advances in instrumentation and methodology have furthered the use of solid-state NMR as a technique for determining the structures and studying the dynamics of molecules involved in complex biological assemblies. Solid-state NMR does not require large crystals, has no inherent size limit, and with appropriate isotopic labeling schemes, supports solving one component of a complex assembly at a time. It is complementary to cryo-EM, in that it provides local, atomic-level detail that can be modeled into larger-scale structures. This review focuses on the development of high-field MAS instrumentation and methodology; including probe design, benchmarking strategies, labeling schemes, and experiments that enable the use of quadrupolar nuclei in biomolecular NMR. Current challenges facing solid-state NMR of biological assemblies and new directions in this dynamic research area are also discussed.
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Affiliation(s)
- Rachel W Martin
- Department of Chemistry, University of California, Irvine 92697-2025, United States; Department of Molecular Biology and Biochemistry, University of California, Irvine 92697-3900, United States.
| | - John E Kelly
- Department of Chemistry, University of California, Irvine 92697-2025, United States
| | - Jessica I Kelz
- Department of Chemistry, University of California, Irvine 92697-2025, United States
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48
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Paul G, Bisio C, Braschi I, Cossi M, Gatti G, Gianotti E, Marchese L. Combined solid-state NMR, FT-IR and computational studies on layered and porous materials. Chem Soc Rev 2018; 47:5684-5739. [PMID: 30014075 DOI: 10.1039/c7cs00358g] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Understanding the structure-property relationship of solids is of utmost relevance for efficient chemical processes and technological applications in industries. This contribution reviews the concept of coupling three well-known characterization techniques (solid-state NMR, FT-IR and computational methods) for the study of solid state materials which possess 2D and 3D architectures and discusses the way it will benefit the scientific communities. It highlights the most fundamental and applied aspects of the proactive combined approach strategies to gather information at a molecular level. The integrated approach involving multiple spectroscopic and computational methods allows achieving an in-depth understanding of the surface, interfacial and confined space processes that are beneficial for the establishment of structure-property relationships. The role of ssNMR/FT-IR spectroscopic properties of probe molecules in monitoring the strength and distribution of catalytic active sites and their accessibility at the porous/layered surface is discussed. Both experimental and theoretical aspects will be considered by reporting relevant examples. This review also identifies and discusses the progress, challenges and future prospects in the field of synthesis and applications of layered and porous solids.
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Affiliation(s)
- Geo Paul
- Department of Science and Technological Innovation, Università del Piemonte Orientale, Viale T. Michel 11, 15121 Alessandria, Italy.
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49
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Wittmann JJ, Eckardt M, Harneit W, Corzilius B. Electron-driven spin diffusion supports crossing the diffusion barrier in MAS DNP. Phys Chem Chem Phys 2018; 20:11418-11429. [PMID: 29645035 DOI: 10.1039/c8cp00265g] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Dynamic nuclear polarization (DNP) can be applied to enhance the sensitivity of solid-state NMR experiments by several orders of magnitude due to microwave-driven transfer of spin polarization from unpaired electrons to nuclei. While the underlying quantum mechanical aspects are sufficiently well understood on a microscopic level, the exact description of the large-scale spin dynamics, usually involving hundreds to thousands of nuclear spins per electron, is still lacking consensus. Generally, it is assumed that nuclear hyperpolarization can only be observed on nuclei which do not experience strong influence of the unpaired electrons and thus being significantly removed from the paramagnetic polarizing agents. At the same time, sufficiently strong hyperfine interaction is required for DNP transfer. Therefore, efficient nuclear spin diffusion from the strongly-interacting nuclei to the NMR-observable bulk is considered to be essential for efficient nuclear hyperpolarization. Based on experimental results obtained on the endohedral fullerene N@C60 as a polarizing agent sparsely diluted in C60, we discuss the effect of the spin-diffusion barrier. We introduce electron-driven spin diffusion (EDSD) as a novel mechanism for nuclear polarization transfer in the proximity of an electron spin which is particularly relevant under magic-angle spinning (MAS) DNP conditions.
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Affiliation(s)
- Johannes J Wittmann
- Institute of Physical and Theoretical Chemistry, Institute of Biophysical Chemistry, and Biomolecular Magnetic Resonance Center (BMRZ), Goethe University Frankfurt, Max-von-Laue-Str. 7-9, 60438 Frankfurt, Germany.
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Dubroca T, Smith AN, Pike KJ, Froud S, Wylde R, Trociewitz B, McKay J, Mentink-Vigier F, van Tol J, Wi S, Brey W, Long JR, Frydman L, Hill S. A quasi-optical and corrugated waveguide microwave transmission system for simultaneous dynamic nuclear polarization NMR on two separate 14.1 T spectrometers. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 289:35-44. [PMID: 29459343 PMCID: PMC5978701 DOI: 10.1016/j.jmr.2018.01.015] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 01/25/2018] [Accepted: 01/25/2018] [Indexed: 05/03/2023]
Abstract
Nuclear magnetic resonance (NMR) is an intrinsically insensitive technique, with Boltzmann distributions of nuclear spin states on the order of parts per million in conventional magnetic fields. To overcome this limitation, dynamic nuclear polarization (DNP) can be used to gain up to three orders of magnitude in signal enhancement, which can decrease experimental time by up to six orders of magnitude. In DNP experiments, nuclear spin polarization is enhanced by transferring the relatively larger electron polarization to NMR active nuclei via microwave irradiation. Here, we describe the design and performance of a quasi-optical system enabling the use of a single 395 GHz gyrotron microwave source to simultaneously perform DNP experiments on two different 14.1 T (1H 600 MHz) NMR spectrometers: one configured for magic angle spinning (MAS) solid state NMR; the other configured for solution state NMR experiments. In particular, we describe how the high power microwave beam is split, transmitted, and manipulated between the two spectrometers. A 13C enhancement of 128 is achieved via the cross effect for alanine, using the nitroxide biradical AMUPol, under MAS-DNP conditions at 110 K, while a 31P enhancement of 160 is achieved via the Overhauser effect for triphenylphosphine using the monoradical BDPA under solution NMR conditions at room temperature. The latter result is the first demonstration of Overhauser DNP in the solution state at a field of 14.1 T (1H 600 MHz). Moreover these results have been produced with large sample volumes (∼100 µL, i.e. 3 mm diameter NMR tubes).
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Affiliation(s)
- Thierry Dubroca
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, FL 32310, USA
| | - Adam N. Smith
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, FL 32310, USA
- Department of Chemistry, University of Florida, 214 Leigh Hall, Gainesville, FL 32611, USA
| | - Kevin J. Pike
- Thomas Keating Ltd., Station Mills, Daux Road, Billingshurst, West Sussex RH14 9SH, UK
| | - Stuart Froud
- Thomas Keating Ltd., Station Mills, Daux Road, Billingshurst, West Sussex RH14 9SH, UK
| | - Richard Wylde
- Thomas Keating Ltd., Station Mills, Daux Road, Billingshurst, West Sussex RH14 9SH, UK
| | - Bianca Trociewitz
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, FL 32310, USA
| | - Johannes McKay
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, FL 32310, USA
| | | | - Johan van Tol
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, FL 32310, USA
| | - Sungsool Wi
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, FL 32310, USA
| | - William Brey
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, FL 32310, USA
| | - Joanna R. Long
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, FL 32310, USA
- Department of Biochemistry and Molecular Biology and National High Magnetic Field Laboratory, PO Box 100245, Gainesville, FL 32610-0245, USA
| | - Lucio Frydman
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, FL 32310, USA
- Department of Chemical and Biological Physics, Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Stephen Hill
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, FL 32310, USA
- Department of Physics, Florida State University, Tallahassee, FL 32306, USA
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