1
|
Kuzhelev AA, Denysenkov V, Ahmad IM, Rogozhnikova OY, Trukhin DV, Bagryanskaya EG, Tormyshev VM, Sigurdsson ST, Prisner TF. Solid-Effect Dynamic Nuclear Polarization in Viscous Liquids at 9.4 T Using Narrow-Line Polarizing Agents. J Am Chem Soc 2023; 145:10268-10274. [PMID: 37104685 DOI: 10.1021/jacs.3c01358] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
Dynamic nuclear polarization (DNP) is a hyperpolarization method that is widely used for increasing the sensitivity of nuclear magnetic resonance (NMR) experiments. DNP is efficient in solid-state and liquid-state NMR, but its implementation in the intermediate state, namely, viscous media, is still less explored. Here, we show that a 1H DNP enhancement of over 50 can be obtained in viscous liquids at a magnetic field of 9.4 T and a temperature of 315 K. This was accomplished by using narrow-line polarizing agents in glycerol, both the water-soluble α,γ-bisdiphenylen-β-phenylallyl (BDPA) and triarylmethyl radicals, and a microwave/RF double-resonance probehead. We observed DNP enhancements with a field profile indicative of the solid effect and investigated the influence of microwave power, temperature, and concentration on the 1H NMR results. To demonstrate potential applications of this new DNP approach for chemistry and biology, we show hyperpolarized 1H NMR spectra of tripeptides, triglycine, and glypromate, in glycerol-d8.
Collapse
Affiliation(s)
- Andrei A Kuzhelev
- Institute of Physical and Theoretical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University Frankfurt am Main, Max von Laue Straße 7, 60438 Frankfurt am Main, Germany
| | - Vasyl Denysenkov
- Institute of Physical and Theoretical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University Frankfurt am Main, Max von Laue Straße 7, 60438 Frankfurt am Main, Germany
| | - Iram M Ahmad
- Department of Chemistry, Science Institute, University of Iceland, Dunhaga 3, 107 Reykjavik, Iceland
| | - Olga Yu Rogozhnikova
- N. N. Vorozhtsov Institute of Organic Chemistry, Siberian Branch of Russian Academy of Sciences (SB RAS), Acad. Lavrentiev Avenue 9, 630090 Novosibirsk, Russia
| | - Dmitry V Trukhin
- N. N. Vorozhtsov Institute of Organic Chemistry, Siberian Branch of Russian Academy of Sciences (SB RAS), Acad. Lavrentiev Avenue 9, 630090 Novosibirsk, Russia
| | - Elena G Bagryanskaya
- N. N. Vorozhtsov Institute of Organic Chemistry, Siberian Branch of Russian Academy of Sciences (SB RAS), Acad. Lavrentiev Avenue 9, 630090 Novosibirsk, Russia
| | - Victor M Tormyshev
- N. N. Vorozhtsov Institute of Organic Chemistry, Siberian Branch of Russian Academy of Sciences (SB RAS), Acad. Lavrentiev Avenue 9, 630090 Novosibirsk, Russia
| | - Snorri Th Sigurdsson
- Department of Chemistry, Science Institute, University of Iceland, Dunhaga 3, 107 Reykjavik, Iceland
| | - Thomas F Prisner
- Institute of Physical and Theoretical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University Frankfurt am Main, Max von Laue Straße 7, 60438 Frankfurt am Main, Germany
| |
Collapse
|
2
|
Rao Y, Venkatesh A, Moutzouri P, Emsley L. 1H Hyperpolarization of Solutions by Overhauser Dynamic Nuclear Polarization with 13C- 1H Polarization Transfer. J Phys Chem Lett 2022; 13:7749-7755. [PMID: 35969266 PMCID: PMC9421900 DOI: 10.1021/acs.jpclett.2c01956] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 08/09/2022] [Indexed: 06/15/2023]
Abstract
Dynamic nuclear polarization (DNP) is a method that can significantly increase the sensitivity of nuclear magnetic resonance. The only effective DNP mechanism for in situ hyperpolarization in solution is Overhauser DNP, which is inefficient for 1H at high magnetic fields. Here we demonstrate the possibility of generating significant 1H hyperpolarization in solution at room temperature. To counter the poor direct 1H Overhauser DNP, we implement steady-state 13C Overhauser DNP in solutions and then transfer the 13C hyperpolarization to 1H via a reverse insensitive nuclei enhanced by polarization transfer scheme. We demonstrate this approach using a 400 MHz gyrotron-equipped 3.2 mm magic angle spinning DNP system to obtain 1H DNP enhancement factors of 48, 8, and 6 for chloroform, tetrachloroethane, and phenylacetylene, respectively, at room temperature.
Collapse
|
3
|
Cheney DJ, Wedge CJ. Sample volume effects in optical overhauser dynamic nuclear polarization. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2022; 337:107170. [PMID: 35240365 DOI: 10.1016/j.jmr.2022.107170] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 02/13/2022] [Accepted: 02/16/2022] [Indexed: 06/14/2023]
Abstract
The optical dynamic nuclear polarization (DNP) method has been proposed as an alternative to microwave pumping as a hyperpolarization method for solution-state NMR studies. Using continuous laser illumination to photogenerate triplet states in the presence of a persistent radical produces chemically-induced dynamic electron polarization (CIDEP) via the radical-triplet pair mechanism (RTPM), with cross-relaxation transferring this to nuclear hyperpolarization via an Overhauser mechanism. Numerical simulations have previously indicated that reducing the sample volume while maintaining a constant optical density can significantly increase the NMR signal enhancement, due to the larger steady-state concentration of triplets obtained. Here we provide the first experimental confirmation of these effects, producing a nearly five-fold increase in the optical DNP enhancement factor just by reducing the sample volume with optimal dye and radical concentrations adjusted for each optical path length. The results are supported with an in depth analysis of volume effects in the numerical model, with which they are in good qualitative agreement. These important observations will impact on the future development of the technique, with particular significance for attempts to apply DNP methods to increase sensitivity for volume-limited biological samples.
Collapse
Affiliation(s)
- Daniel J Cheney
- Department of Chemical Sciences, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, United Kingdom
| | - Christopher J Wedge
- Department of Chemical Sciences, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, United Kingdom.
| |
Collapse
|
4
|
Eills J, Hale W, Utz M. Synergies between Hyperpolarized NMR and Microfluidics: A Review. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2022; 128:44-69. [PMID: 35282869 DOI: 10.1016/j.pnmrs.2021.09.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 09/10/2021] [Accepted: 09/11/2021] [Indexed: 06/14/2023]
Abstract
Hyperpolarized nuclear magnetic resonance and lab-on-a-chip microfluidics are two dynamic, but until recently quite distinct, fields of research. Recent developments in both areas increased their synergistic overlap. By microfluidic integration, many complex experimental steps can be brought together onto a single platform. Microfluidic devices are therefore increasingly finding applications in medical diagnostics, forensic analysis, and biomedical research. In particular, they provide novel and powerful ways to culture cells, cell aggregates, and even functional models of entire organs. Nuclear magnetic resonance is a non-invasive, high-resolution spectroscopic technique which allows real-time process monitoring with chemical specificity. It is ideally suited for observing metabolic and other biological and chemical processes in microfluidic systems. However, its intrinsically low sensitivity has limited its application. Recent advances in nuclear hyperpolarization techniques may change this: under special circumstances, it is possible to enhance NMR signals by up to 5 orders of magnitude, which dramatically extends the utility of NMR in the context of microfluidic systems. Hyperpolarization requires complex chemical and/or physical manipulations, which in turn may benefit from microfluidic implementation. In fact, many hyperpolarization methodologies rely on processes that are more efficient at the micro-scale, such as molecular diffusion, penetration of electromagnetic radiation into a sample, or restricted molecular mobility on a surface. In this review we examine the confluence between the fields of hyperpolarization-enhanced NMR and microfluidics, and assess how these areas of research have mutually benefited one another, and will continue to do so.
Collapse
Affiliation(s)
- James Eills
- Institute for Physics, Johannes Gutenberg University, D-55090 Mainz, Germany; GSI Helmholtzzentrum für Schwerionenforschung GmbH, Helmholtz-Institut Mainz, 55128 Mainz, Germany.
| | - William Hale
- Department of Chemistry, University of Florida, 32611, USA
| | - Marcel Utz
- School of Chemistry, University of Southampton, SO17 1BJ, UK.
| |
Collapse
|
5
|
Kuzhelev AA, Dai D, Denysenkov V, Prisner TF. Solid-like Dynamic Nuclear Polarization Observed in the Fluid Phase of Lipid Bilayers at 9.4 T. J Am Chem Soc 2022; 144:1164-1168. [PMID: 35029974 DOI: 10.1021/jacs.1c12837] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Dynamic nuclear polarization (DNP) is a powerful method to enhance NMR sensitivity. Much progress has been achieved recently to optimize DNP performance at high magnetic fields in solid-state samples, mostly by utilizing the solid or the cross effect. In liquids, only the Overhauser mechanism is active, which exhibits a DNP field profile matching the EPR line shape of the radical, distinguishable from other DNP mechanisms. Here, we observe DNP enhancements with a field profile indicative of the solid effect and thermal mixing at ∼320 K and a magnetic field of 9.4 T in the fluid phase of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) lipid bilayers doped with the radical BDPA (1,3-bis(diphenylene)-2-phenylallyl). This interesting observation might open up new perspectives for DNP applications in macromolecular systems at ambient temperatures.
Collapse
Affiliation(s)
- Andrei A Kuzhelev
- Goethe University Frankfurt am Main, Institute of Physical and Theoretical Chemistry and Center for Biomolecular Magnetic Resonance, Max von Laue Str. 7, 60438 Frankfurt am Main, Germany
| | - Danhua Dai
- Goethe University Frankfurt am Main, Institute of Physical and Theoretical Chemistry and Center for Biomolecular Magnetic Resonance, Max von Laue Str. 7, 60438 Frankfurt am Main, Germany
| | - Vasyl Denysenkov
- Goethe University Frankfurt am Main, Institute of Physical and Theoretical Chemistry and Center for Biomolecular Magnetic Resonance, Max von Laue Str. 7, 60438 Frankfurt am Main, Germany
| | - Thomas F Prisner
- Goethe University Frankfurt am Main, Institute of Physical and Theoretical Chemistry and Center for Biomolecular Magnetic Resonance, Max von Laue Str. 7, 60438 Frankfurt am Main, Germany
| |
Collapse
|
6
|
Zhang Z, Jiang Y, Pi H, Chen H, Liu C, Feng J, Liu M. THz-enhanced dynamic nuclear polarized liquid spectrometer. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2021; 330:107044. [PMID: 34352701 DOI: 10.1016/j.jmr.2021.107044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 07/21/2021] [Accepted: 07/22/2021] [Indexed: 06/13/2023]
Abstract
Dynamic nuclear polarization (DNP) technology can be utilized to dramatically enhance NMR signal. In this paper, we report on the development of a self-constructed 5 T DNP spectrometer for liquid samples and the 13C DNP enhancement achieved with this spectrometer. The DNP spectrometer is comprised of a wide-bore superconducting magnet, a home-made console, a dual resonance probe and a self-built 140 GHz microwave source for the spectrometer. Specifically, a microwave source of traveling wave tube (TWT) amplifier has been developed, which can provide a maximum power output of 4.4 W and a wide frequency tuning range of 1 GHz. The excellent performance of our built liquid-state DNP spectrometer is verified by the observation of more than 100-fold DNP enhancement of the 13C NMR signal for liquid 13CCl4 sample. Our result shows the superiority of DNP technology in the liquid-state high-field NMR spectrometer.
Collapse
Affiliation(s)
- Zhekai Zhang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yi Jiang
- Institute of Applied Electronics of CAEP, Mianyang 621900, China
| | - Haiya Pi
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hongbin Chen
- Institute of Applied Electronics of CAEP, Mianyang 621900, China.
| | - Chaoyang Liu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China; Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China.
| | - Jiwen Feng
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China.
| | - Maili Liu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China; Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
| |
Collapse
|
7
|
Abhyankar N, Szalai V. Challenges and Advances in the Application of Dynamic Nuclear Polarization to Liquid-State NMR Spectroscopy. J Phys Chem B 2021; 125:5171-5190. [PMID: 33960784 PMCID: PMC9871957 DOI: 10.1021/acs.jpcb.0c10937] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Nuclear magnetic resonance (NMR) spectroscopy is a powerful method to study the molecular structure and dynamics of materials. The inherently low sensitivity of NMR spectroscopy is a consequence of low spin polarization. Hyperpolarization of a spin ensemble is defined as a population difference between spin states that far exceeds what is expected from the Boltzmann distribution for a given temperature. Dynamic nuclear polarization (DNP) can overcome the relatively low sensitivity of NMR spectroscopy by using a paramagnetic matrix to hyperpolarize a nuclear spin ensemble. Application of DNP to NMR can result in sensitivity gains of up to four orders of magnitude compared to NMR without DNP. Although DNP NMR is now more routinely utilized for solid-state (ss) NMR spectroscopy, it has not been exploited to the same degree for liquid-state samples. This Review will consider challenges and advances in the application of DNP NMR to liquid-state samples. The Review is organized into four sections: (i) mechanisms of DNP NMR relevant to hyperpolarization of liquid samples; (ii) applications of liquid-state DNP NMR; (iii) available detection schemes for liquid-state samples; and (iv) instrumental challenges and outlook for liquid-state DNP NMR.
Collapse
Affiliation(s)
- Nandita Abhyankar
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD 20742, USA,National Institute of Standards and Technology, Gaithersburg, MD 20899, USA,Corresponding authors: ,
| | - Veronika Szalai
- National Institute of Standards and Technology, Gaithersburg, MD 20899, USA,Corresponding authors: ,
| |
Collapse
|
8
|
Levien M, Reinhard M, Hiller M, Tkach I, Bennati M, Orlando T. Spin density localization and accessibility of organic radicals affect liquid-state DNP efficiency. Phys Chem Chem Phys 2021; 23:4480-4485. [PMID: 33599637 DOI: 10.1039/d0cp05796g] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We report a large variation in liquid DNP performance of up to a factor of about five in coupling factor among organic radicals commonly used as polarizing agents. A comparative study of 1H and 13C DNP in model systems shows the impact of the spin density distribution and accessibility of the radical site by the target molecule.
Collapse
Affiliation(s)
- Marcel Levien
- ESR Spectroscopy Group, Max Planck Institute for Biophysical Chemistry, Am Faßberg 11, Göttigen, Germany.
| | | | | | | | | | | |
Collapse
|
9
|
Nevzorov AA, Marek A, Milikisiyants S, Smirnov AI. Characterization of photonic band resonators for DNP NMR of thin film samples at 7 T magnetic field. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2021; 323:106893. [PMID: 33418455 PMCID: PMC8362290 DOI: 10.1016/j.jmr.2020.106893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 12/09/2020] [Accepted: 12/10/2020] [Indexed: 06/12/2023]
Abstract
Polarization of nuclear spins via Dynamic Nuclear Polarization (DNP) relies on generating sufficiently high mm-wave B1e fields over the sample, which could be achieved by developing suitable resonance structures. Recently, we have introduced one-dimensional photonic band gap (1D PBG) resonators for DNP and reported on prototype devices operating at ca. 200 GHz electron resonance frequency. Here we systematically compare the performance of five (5) PBG resonators constructed from various alternating dielectric layers by monitoring the DNP effect on natural-abundance 13C spins in synthetic diamond microparticles embedded into a commercial polyester-based lapping film of just 3 mil (76 μm) thickness. An odd-numbered configuration of dielectric layers for 1D PBG resonator was introduced to achieve further B1e enhancements. Among the PBG configurations tested, combinations of high-ε perovskite LiTaO3 together with AlN as well as AlN with optical quartz wafers have resulted in ca. 40 to over 50- fold gains in the average mm-wave power over the sample vs. the mirror-only configuration. The results are rationalized in terms of the electromagnetic energy distribution inside the resonators obtained analytically and from COMSOL simulations. It was found that average of B1e2 over the sample strongly depends on the arrangement of the dielectric layers that are the closest to the sample, which favors odd-numbered PBG resonator configurations for their use in DNP.
Collapse
Affiliation(s)
- Alexander A Nevzorov
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27695-8204, United States.
| | - Antonin Marek
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27695-8204, United States
| | - Sergey Milikisiyants
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27695-8204, United States
| | - Alex I Smirnov
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27695-8204, United States.
| |
Collapse
|
10
|
Murzakhanov FF, Mamin GV, Goldberg MA, Knotko AV, Gafurov MR, Orlinskii SB. EPR of Radiation-Induced Nitrogen Centers in Hydroxyapatite: New Approaches to the Study of Electron-Nuclear Interactions. RUSS J COORD CHEM+ 2020. [DOI: 10.1134/s1070328420110044] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
|
11
|
Hyperpolarization via dissolution dynamic nuclear polarization: new technological and methodological advances. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2020; 34:5-23. [PMID: 33185800 DOI: 10.1007/s10334-020-00894-w] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 10/04/2020] [Accepted: 10/23/2020] [Indexed: 12/20/2022]
Abstract
Dissolution-DNP is a method to boost liquid-state NMR sensitivity by several orders of magnitude. The technique consists in hyperpolarizing samples by solid-state dynamic nuclear polarization at low temperature and moderate magnetic field, followed by an instantaneous melting and dilution of the sample happening inside the polarizer. Although the technique is well established and the outstanding signal enhancement paved the way towards many applications precluded to conventional NMR, the race to develop new methods allowing higher throughput, faster and higher polarization, and longer exploitation of the signal is still vivid. In this work, we review the most recent advances on dissolution-DNP methods trying to overcome the original technique's shortcomings. The review describes some of the new approaches in the field, first, in terms of sample formulation and properties, and second, in terms of instrumentation.
Collapse
|
12
|
Tamski M, Milani J, Roussel C, Ansermet JP. Electrochemical Overhauser dynamic nuclear polarization. Phys Chem Chem Phys 2020; 22:17769-17776. [PMID: 32766651 DOI: 10.1039/d0cp00984a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Nuclear Magnetic Resonance (NMR) spectroscopy suffers from low sensitivity due to the low nuclear spin polarization obtained within practically achievable external magnetic fields. Dynamic Nuclear Polarization (DNP) refers to techniques that increase the NMR signal intensity by transferring spin polarization from electrons to the nuclei. Until now, a common method of introducing unpaired electrons to a sample has been to add to it a radical such as TEMPOL or trityl. The alternative we address here is to use electrochemical oxidation and/or reduction of a redox mediator to generate radical species that can be used for DNP. Surprisingly, the potential of electrochemically-generated radicals as a source of hyperpolarization for DNP has not been investigated so far. In this communication, we show the proof of principle of performing an in situ DNP experiment at a low magnetic field in a solution phase, with electrochemically generated methyl viologen cation radicals. Electrochemistry as a source of radicals can offer exciting prospects for DNP. The electrode may be one that generates radicals with a high spin polarization. The concentration of radicals in the sample can be adjusted by changing the duration and magnitude of the applied electrode potential. Removal of the radical from the sample after spin polarization transfer is also possible, thereby increasing the lifetime of the nuclear hyperpolarization.
Collapse
Affiliation(s)
- Mika Tamski
- Institut de physique, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
| | | | | | | |
Collapse
|
13
|
Dubroca T, Wi S, van Tol J, Frydman L, Hill S. Large volume liquid state scalar Overhauser dynamic nuclear polarization at high magnetic field. Phys Chem Chem Phys 2019; 21:21200-21204. [PMID: 31310269 DOI: 10.1039/c9cp02997d] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Dynamic Nuclear Polarization (DNP) can increase the sensitivity of Nuclear Magnetic Resonance (NMR), but it is challenging in the liquid state at high magnetic fields. In this study we demonstrate significant enhancements of NMR signals (up to 70 on 13C) in the liquid state by scalar Overhauser DNP at 14.1 T, with high resolution (∼0.1 ppm) and relatively large sample volume (∼100 μL).
Collapse
|
14
|
Orlando T, Dervişoğlu R, Levien M, Tkach I, Prisner TF, Andreas LB, Denysenkov VP, Bennati M. Dynamic Nuclear Polarization of 13
C Nuclei in the Liquid State over a 10 Tesla Field Range. Angew Chem Int Ed Engl 2018; 58:1402-1406. [DOI: 10.1002/anie.201811892] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Indexed: 12/16/2022]
Affiliation(s)
- Tomas Orlando
- Research Group of EPR Spectroscopy; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
| | - Rıza Dervişoğlu
- Department of NMR Based Structural Biology; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
| | - Marcel Levien
- Research Group of EPR Spectroscopy; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
- Department of Chemistry; Georg-August-University; Tammannstrasse 4 Göttingen Germany
| | - Igor Tkach
- Research Group of EPR Spectroscopy; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
| | - Thomas F. Prisner
- Institute of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic Resonance; Goethe University; Max-von-Laue-Strasse 7 Frankfurt am Main Germany
| | - Loren B. Andreas
- Department of NMR Based Structural Biology; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
| | - Vasyl P. Denysenkov
- Institute of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic Resonance; Goethe University; Max-von-Laue-Strasse 7 Frankfurt am Main Germany
| | - Marina Bennati
- Research Group of EPR Spectroscopy; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
- Department of Chemistry; Georg-August-University; Tammannstrasse 4 Göttingen Germany
| |
Collapse
|
15
|
Orlando T, Dervişoğlu R, Levien M, Tkach I, Prisner TF, Andreas LB, Denysenkov VP, Bennati M. Dynamic Nuclear Polarization of 13
C Nuclei in the Liquid State over a 10 Tesla Field Range. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201811892] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Tomas Orlando
- Research Group of EPR Spectroscopy; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
| | - Rıza Dervişoğlu
- Department of NMR Based Structural Biology; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
| | - Marcel Levien
- Research Group of EPR Spectroscopy; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
- Department of Chemistry; Georg-August-University; Tammannstrasse 4 Göttingen Germany
| | - Igor Tkach
- Research Group of EPR Spectroscopy; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
| | - Thomas F. Prisner
- Institute of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic Resonance; Goethe University; Max-von-Laue-Strasse 7 Frankfurt am Main Germany
| | - Loren B. Andreas
- Department of NMR Based Structural Biology; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
| | - Vasyl P. Denysenkov
- Institute of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic Resonance; Goethe University; Max-von-Laue-Strasse 7 Frankfurt am Main Germany
| | - Marina Bennati
- Research Group of EPR Spectroscopy; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
- Department of Chemistry; Georg-August-University; Tammannstrasse 4 Göttingen Germany
| |
Collapse
|
16
|
Chen HY, Tycko R. Temperature-Dependent Nuclear Spin Relaxation Due to Paramagnetic Dopants Below 30 K: Relevance to DNP-Enhanced Magnetic Resonance Imaging. J Phys Chem B 2018; 122:11731-11742. [PMID: 30277390 DOI: 10.1021/acs.jpcb.8b07958] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Dynamic nuclear polarization (DNP) can increase nuclear magnetic resonance (NMR) signal strengths by factors of 100 or more at low temperatures. In magnetic resonance imaging (MRI), signal enhancements from DNP potentially lead to enhancements in image resolution. However, the paramagnetic dopants required for DNP also reduce nuclear spin relaxation times, producing signal losses that may cancel the signal enhancements from DNP. Here we investigate the dependence of 1H NMR relaxation times, including T1ρ and T2, under conditions of Lee-Goldburg 1H-1H decoupling and pulsed spin locking, on temperature and dopant concentration in frozen solutions that contain the trinitroxide compound DOTOPA. We find that relaxation times become longer at temperatures below 10 K, where DOTOPA electron spins become strongly polarized at equilibrium in a 9.39 T magnetic field. We show that the dependences of relaxation times on temperature and DOTOPA concentration can be reproduced qualitatively (although not quantitatively) by detailed simulations of magnetic field fluctuations due to flip-flop transitions in a system of dipole-coupled electron spin magnetic moments. These results have implications for ongoing attempts to reach submicron resolution in inductively detected MRI at very low temperatures.
Collapse
Affiliation(s)
- Hsueh-Ying Chen
- Laboratory of Chemical Physics National Institute of Diabetes and Digestive and Kidney Diseases , National Institutes of Health , Bethesda , Maryland 20892-0520 , United States
| | - Robert Tycko
- Laboratory of Chemical Physics National Institute of Diabetes and Digestive and Kidney Diseases , National Institutes of Health , Bethesda , Maryland 20892-0520 , United States
| |
Collapse
|
17
|
Deryugina AV, Oshevenskiy LV, Talamanova MN, Tsvetkov AI, Shabalin MA, Glyavin MY, Krylov VN. Electrokinetic and Biochemical Changes in Erythrocytes under the Action of Terahertz Range Electromagnetic Waves. Biophysics (Nagoya-shi) 2017. [DOI: 10.1134/s0006350917060033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
|
18
|
van Meerten SGJ, Tayler MCD, Kentgens APM, van Bentum PJM. Towards Overhauser DNP in supercritical CO(2). JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 267:30-6. [PMID: 27082277 DOI: 10.1016/j.jmr.2016.04.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 04/01/2016] [Accepted: 04/03/2016] [Indexed: 05/14/2023]
Abstract
Overhauser Dynamic Nuclear Polarization (ODNP) is a well known technique to improve NMR sensitivity in the liquid state, where the large polarization of an electron spin is transferred to a nucleus of interest by cross-relaxation. The efficiency of the Overhauser mechanism for dipolar interactions depends critically on fast local translational dynamics at the timescale of the inverse electron Larmor frequency. The maximum polarization enhancement that can be achieved for (1)H at high magnetic fields benefits from a low viscosity solvent. In this paper we investigate the option to use supercritical CO2 as a solvent for Overhauser DNP. We have investigated the diffusion constants and longitudinal nuclear relaxation rates of toluene in high pressure CO2. The change in (1)H T1 by addition of TEMPO radical was analyzed to determine the Overhauser cross-relaxation in such a mixture, and is compared with calculations based on the Force Free Hard Sphere (FFHS) model. By analyzing the relaxation data within this model we find translational correlation times in the range of 2-4ps, depending on temperature, pressure and toluene concentration. Such short correlation times may be instrumental for future Overhauser DNP applications at high magnetic fields, as are commonly used in NMR. Preliminary DNP experiments have been performed at 3.4T on high pressure superheated water and model systems such as toluene in high pressure CO2.
Collapse
Affiliation(s)
- S G J van Meerten
- Radboud University, Institute for Molecules and Materials, Heyendaalseweg 135, 6525AJ Nijmegen, The Netherlands
| | - M C D Tayler
- Radboud University, Institute for Molecules and Materials, Heyendaalseweg 135, 6525AJ Nijmegen, The Netherlands
| | - A P M Kentgens
- Radboud University, Institute for Molecules and Materials, Heyendaalseweg 135, 6525AJ Nijmegen, The Netherlands
| | - P J M van Bentum
- Radboud University, Institute for Molecules and Materials, Heyendaalseweg 135, 6525AJ Nijmegen, The Netherlands.
| |
Collapse
|
19
|
Ravera E, Luchinat C, Parigi G. Basic facts and perspectives of Overhauser DNP NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 264:78-87. [PMID: 26920833 DOI: 10.1016/j.jmr.2015.12.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 12/16/2015] [Accepted: 12/17/2015] [Indexed: 05/03/2023]
Abstract
After the first surprisingly large (1)H DNP enhancements of the water signal in aqueous solutions of nitroxide radicals observed at high magnetic fields, Overhauser DNP is gaining increasing attention for a number of applications now flourishing, showing the potentialities of this mechanism in solution and solid state NMR as well as in MRI. Unexpected Overhauser DNP enhancements in insulating solids were recently measured at 100K, with a magnitude which increases with the applied magnetic field. We recapitulate here the theoretical premises of Overhauser DNP in solution and analyze the effects of the various parameters on the efficacy of the mechanism, underlining the link between the DNP enhancements and the field dependent relaxation properties. Promisingly, more effective DNP enhancements are expected by exploiting the potentialities offered by (13)C detection and the use of supercritical fluids.
Collapse
Affiliation(s)
- Enrico Ravera
- Magnetic Resonance Center (CERM) and Department of Chemistry "Ugo Schiff", University of Florence, Italy
| | - Claudio Luchinat
- Magnetic Resonance Center (CERM) and Department of Chemistry "Ugo Schiff", University of Florence, Italy
| | - Giacomo Parigi
- Magnetic Resonance Center (CERM) and Department of Chemistry "Ugo Schiff", University of Florence, Italy.
| |
Collapse
|
20
|
Prisner T, Denysenkov V, Sezer D. Liquid state DNP at high magnetic fields: Instrumentation, experimental results and atomistic modelling by molecular dynamics simulations. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 264:68-77. [PMID: 26920832 DOI: 10.1016/j.jmr.2015.11.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 11/11/2015] [Accepted: 11/12/2015] [Indexed: 05/14/2023]
Abstract
Dynamic nuclear polarization (DNP) at high magnetic fields has recently become one of the major research areas in magnetic resonance spectroscopy and imaging. Whereas much work has been devoted to experiments where the polarization transfer from the electron spin to the nuclear spin is performed in the solid state, only a few examples exist of experiments where the polarization transfer is performed in the liquid state. Here we describe such experiments at a magnetic field of 9.2 T, corresponding to a nuclear Larmor frequency of 400 MHz for proton spins and an excitation frequency of 263 GHz for the electron spins. The technical requirements to perform such experiments are discussed in the context of the double resonance structures that we have implemented. The experimental steps that allowed access to the enhancement factors for proton spins of several organic solvents with nitroxide radicals as polarizing agents are described. A computational scheme for calculating the coupling factors from molecular dynamics (MD) simulations is outlined and used to highlight the limitations of the classical models based on translational and rotational motion that are typically employed to quantify the observed coupling factors. The ability of MD simulations to predict enhancements for a variety of radicals and solvent molecules at any magnetic field strength should prove useful in optimizing experimental conditions for DNP in the liquid state.
Collapse
Affiliation(s)
- Thomas Prisner
- Institute of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic Resonance, Goethe University Frankfurt, Germany.
| | - Vasyl Denysenkov
- Institute of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic Resonance, Goethe University Frankfurt, Germany
| | - Deniz Sezer
- Faculty of Engineering and Natural Sciences, Sabancı University, Orhanlı-Tuzla, 34956 Istanbul, Turkey.
| |
Collapse
|
21
|
van Bentum J, van Meerten B, Sharma M, Kentgens A. Perspectives on DNP-enhanced NMR spectroscopy in solutions. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 264:59-67. [PMID: 26920831 DOI: 10.1016/j.jmr.2016.01.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 01/12/2016] [Accepted: 01/13/2016] [Indexed: 05/03/2023]
Abstract
More than 60 years after the seminal work of Albert Overhauser on dynamic nuclear polarization by dynamic cross relaxation of coupled electron-nuclear spin systems, the quest for sensitivity enhancement in NMR spectroscopy is as pressing as ever. In this contribution we will review the status and perspectives for dynamic nuclear polarization in the liquid state. An appealing approach seems to be the use of supercritical solvents that may allow an extension of the Overhauser mechanism towards common high magnetic fields. A complementary approach is the use of solid state DNP on frozen solutions, followed by a rapid dissolution or in-situ melting step and NMR detection with substantially enhanced polarization levels in the liquid state. We will review recent developments in the field and discuss perspectives for the near future.
Collapse
|
22
|
Rosay M, Blank M, Engelke F. Instrumentation for solid-state dynamic nuclear polarization with magic angle spinning NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 264:88-98. [PMID: 26920834 DOI: 10.1016/j.jmr.2015.12.026] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 12/17/2015] [Accepted: 12/18/2015] [Indexed: 05/08/2023]
Abstract
Advances in dynamic nuclear polarization (DNP) instrumentation and methodology have been key factors in the recent growth of solid-state DNP NMR applications. We review the current state of the art of solid-state DNP NMR instrumentation primarily based on available commercial platforms. We start with a general system overview, including options for microwave sources and DNP NMR probes, and then focus on specific developments for DNP at 100K with magic angle spinning (MAS). Gyrotron microwave sources, passive components to transmit microwaves, the DNP MAS probe, a cooling device for low-temperature MAS, and sample preparation procedures including radicals for DNP are considered.
Collapse
Affiliation(s)
- Melanie Rosay
- Bruker-Biospin, 15 Fortune Drive, Billerica, MA 01730, USA.
| | - Monica Blank
- Communications and Power Industries, 811 Hansen Way, Palo Alto, CA 94304, USA.
| | - Frank Engelke
- Bruker-Biospin, Silberstreifen 4, 76287 Rheinstetten, Germany.
| |
Collapse
|
23
|
Kaminker I, Shimon D, Hovav Y, Feintuch A, Vega S. Heteronuclear DNP of protons and deuterons with TEMPOL. Phys Chem Chem Phys 2016; 18:11017-41. [DOI: 10.1039/c5cp06689a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Dynamic nuclear polarization (DNP) experiments on samples with several types of magnetic nuclei sometimes exhibit “cross-talk” between the nuclei, such as different nuclei having DNP spectra with similar shapes and enhancements.
Collapse
Affiliation(s)
| | - D. Shimon
- Weizmann Institute of Science
- Rehovot
- Israel
| | - Y. Hovav
- Weizmann Institute of Science
- Rehovot
- Israel
| | | | - S. Vega
- Weizmann Institute of Science
- Rehovot
- Israel
| |
Collapse
|
24
|
Ardenkjaer-Larsen JH, Boebinger GS, Comment A, Duckett S, Edison AS, Engelke F, Griesinger C, Griffin RG, Hilty C, Maeda H, Parigi G, Prisner T, Ravera E, van Bentum J, Vega S, Webb A, Luchinat C, Schwalbe H, Frydman L. Facing and Overcoming Sensitivity Challenges in Biomolecular NMR Spectroscopy. Angew Chem Int Ed Engl 2015; 54:9162-85. [PMID: 26136394 PMCID: PMC4943876 DOI: 10.1002/anie.201410653] [Citation(s) in RCA: 216] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Revised: 01/26/2015] [Indexed: 11/07/2022]
Abstract
In the Spring of 2013, NMR spectroscopists convened at the Weizmann Institute in Israel to brainstorm on approaches to improve the sensitivity of NMR experiments, particularly when applied in biomolecular settings. This multi-author interdisciplinary Review presents a state-of-the-art description of the primary approaches that were considered. Topics discussed included the future of ultrahigh-field NMR systems, emerging NMR detection technologies, new approaches to nuclear hyperpolarization, and progress in sample preparation. All of these are orthogonal efforts, whose gains could multiply and thereby enhance the sensitivity of solid- and liquid-state experiments. While substantial advances have been made in all these areas, numerous challenges remain in the quest of endowing NMR spectroscopy with the sensitivity that has characterized forms of spectroscopies based on electrical or optical measurements. These challenges, and the ways by which scientists and engineers are striving to solve them, are also addressed.
Collapse
Affiliation(s)
- Jan-Henrik Ardenkjaer-Larsen
- GE Healthcare, Broendby, Denmark; Department of Electrical Engineering, Technical University of Denmark, Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital Hvidovre (Denmark)
| | - Gregory S Boebinger
- U.S. National High Magnetic Field Lab, Florida State University, Tallahassee, FL 32310 (USA)
| | - Arnaud Comment
- Institute of Physics of Biological Systems, Ecole Polytechnique Fédérale de Lausanne, Lausanne (Switzerland)
| | - Simon Duckett
- Department of Chemistry, University of York, Heslington, York, YO10 5DD (UK)
| | - Arthur S Edison
- Department of Biochemistry & Molecular Biology, University of Florida, Gainesville, FL 32610 (USA)
| | | | | | - Robert G Griffin
- Department of Chemistry and Francis Bitter Magnet Lab, MIT, Cambridge, MA 02139-4703 (USA)
| | - Christian Hilty
- Department of Chemistry, Texas A&M University, College Station (USA)
| | - Hidaeki Maeda
- Riken Center for Life Science Technologies, Yokohama, Kanagawa (Japan)
| | - Giacomo Parigi
- CERM and Department of Chemistry, University of Florence, Sesto Fiorentino (Italy)
| | - Thomas Prisner
- Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt, Max-von-Laue-Strasse 7, 60438 Frankfurt am Main (Germany)
| | - Enrico Ravera
- CERM and Department of Chemistry, University of Florence, Sesto Fiorentino (Italy)
| | | | - Shimon Vega
- Chemical Physics Department, Weizmann Institute of Science, Rehovot (Israel)
| | - Andrew Webb
- Department of Radiology, C. J. Gorter Center for High Field MRI, Leiden University Medical Center (The Netherlands)
| | - Claudio Luchinat
- CERM and Department of Chemistry, University of Florence, Sesto Fiorentino (Italy).
| | - Harald Schwalbe
- Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt, Max-von-Laue-Strasse 7, 60438 Frankfurt am Main (Germany).
| | - Lucio Frydman
- Chemical Physics Department, Weizmann Institute of Science, Rehovot (Israel).
| |
Collapse
|
25
|
Ardenkjaer-Larsen JH, Boebinger GS, Comment A, Duckett S, Edison AS, Engelke F, Griesinger C, Griffin RG, Hilty C, Maeda H, Parigi G, Prisner T, Ravera E, van Bentum J, Vega S, Webb A, Luchinat C, Schwalbe H, Frydman L. Neue Ansätze zur Empfindlichkeitssteigerung in der biomolekularen NMR-Spektroskopie. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201410653] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|
26
|
Shimon D, Hovav Y, Kaminker I, Feintuch A, Goldfarb D, Vega S. Simultaneous DNP enhancements of (1)H and (13)C nuclei: theory and experiments. Phys Chem Chem Phys 2015; 17:11868-83. [PMID: 25869779 DOI: 10.1039/c5cp00406c] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
DNP on heteronuclear spin systems often results in interesting phenomena such as the polarization enhancement of one nucleus during MW irradiation at the "forbidden" transition frequencies of another nucleus or the polarization transfer between the nuclei without MW irradiation. In this work we discuss the spin dynamics in a four-spin model system of the form {ea-eb-((1)H,(13)C)}, with the Larmor frequencies ωa, ωb, ωH and ωC, by performing Liouville space simulations. This spin system exhibits the common (1)H solid effect (SE), (13)C cross effect (CE) and in addition high order CE-DNP enhancements. Here we show, in particular, the "proton shifted (13)C-CE" mechanism that results in (13)C polarization when the model system, at one of its (13)C-CE conditions, is excited by a MW field at the zero quantum or double quantum electron-proton transitions ωMW = ωa ± ωH and ωMW = ωb ± ωH. Furthermore, we introduce the "heteronuclear" CE mechanism that becomes efficient when the system is at one of its combined CE conditions |ωa - ωb| = |ωH ± ωC|. At these conditions, simulations of the four-spin system show polarization transfer processes between the nuclei, during and without MW irradiation, resembling the polarization exchange effects often discussed in the literature. To link the "microscopic" four-spin simulations to the experimental results we use DNP lineshape simulations based on "macroscopic" rate equations describing the electron and nuclear polarization dynamics in large spin systems. This approach is applied based on electron-electron double resonance (ELDOR) measurements that show strong (1)H-SE features outside the EPR frequency range. Simulated ELDOR spectra combined with the indirect (13)C-CE (iCE) mechanism, result in additional "proton shifted (13)C-CE" features that are similar to the experimental ones. These features are also observed experimentally in (13)C-DNP spectra of a sample containing 15 mM of trityl in a glass forming solution of (13)C-glycerol/H2O and are analyzed by calculating the basic (13)C-SE and (13)C-iCE shapes using simulated ELDOR spectra that were fitted to the experimental ones.
Collapse
Affiliation(s)
- Daphna Shimon
- Department of Chemical Physics, Weizmann Institute of Science, Rehovot, Israel.
| | | | | | | | | | | |
Collapse
|
27
|
Pravdivtsev AN, Yurkovskaya AV, Vieth HM, Ivanov KL. RF-SABRE: A Way to Continuous Spin Hyperpolarization at High Magnetic Fields. J Phys Chem B 2015; 119:13619-29. [DOI: 10.1021/acs.jpcb.5b03032] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Andrey N. Pravdivtsev
- International
Tomography Center, Siberian Branch of the Russian Academy of Science, Institutskaya 3a, Novosibirsk, 630090, Russia
- Novosibirsk State University, Pirogova
2, Novosibirsk, 630090, Russia
| | - Alexandra V. Yurkovskaya
- International
Tomography Center, Siberian Branch of the Russian Academy of Science, Institutskaya 3a, Novosibirsk, 630090, Russia
- Novosibirsk State University, Pirogova
2, Novosibirsk, 630090, Russia
| | - Hans-Martin Vieth
- Institut
für Experimentalphysik, Freie Universität of Berlin, Arnimallee
14, Berlin, 14195, Germany
| | - Konstantin L. Ivanov
- International
Tomography Center, Siberian Branch of the Russian Academy of Science, Institutskaya 3a, Novosibirsk, 630090, Russia
- Novosibirsk State University, Pirogova
2, Novosibirsk, 630090, Russia
| |
Collapse
|
28
|
Neugebauer P, Krummenacker JG, Denysenkov VP, Helmling C, Luchinat C, Parigi G, Prisner TF. High-field liquid state NMR hyperpolarization: a combined DNP/NMRD approach. Phys Chem Chem Phys 2015; 16:18781-7. [PMID: 25078259 DOI: 10.1039/c4cp02451f] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Here we show how fast dynamics between radicals and solvent molecules in liquid solutions can be detected by comparison of coupling factors determined by nuclear magnetic relaxation dispersion (NMRD) measurements and dynamic nuclear polarization (DNP) enhancement measurements at high magnetic field (9.2 T). This is important for a theoretical understanding of the Overhauser DNP mechanism at high magnetic fields and thus for optimization of the DNP agent/target system for high resolution liquid state NMR applications. Mixtures of the solution of TEMPOL radicals in water, toluene, acetone and DMSO have been investigated. The results are compared to the classical hard-sphere model and molecular dynamic simulations. Our results clearly indicate that fast sub-ps dynamics, which are not related to classical rotational or translational motion of the molecules, significantly contribute to the Overhauser DNP mechanism at high magnetic fields.
Collapse
Affiliation(s)
- Petr Neugebauer
- Institute of Physical and Theoretical Chemistry and Center for Biomolecular Magnetic Resonance (BMRZ), Goethe-University, Max-von-Laue-Str. 7, 60438, Frankfurt am Main, Germany.
| | | | | | | | | | | | | |
Collapse
|
29
|
Glyavin MY, Chirkov AV, Denisov GG, Fokin AP, Kholoptsev VV, Kuftin AN, Luchinin AG, Golubyatnikov GY, Malygin VI, Morozkin MV, Manuilov VN, Proyavin MD, Sedov AS, Sokolov EV, Tai EM, Tsvetkov AI, Zapevalov VE. Experimental tests of a 263 GHz gyrotron for spectroscopic applications and diagnostics of various media. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2015; 86:054705. [PMID: 26026544 DOI: 10.1063/1.4921322] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A 263 GHz continuous-wave (CW) gyrotron was developed at the IAP RAS for future applications as a microwave power source in Dynamic Nuclear Polarization / Nuclear magnetic resonance (DNP/NMR) spectrometers. A new experimental facility with a computerized control was built to test this and subsequent gyrotrons. We obtained the maximum CW power up to 1 kW in the 15 kV/0.4 A operation regime. The power about 10 W, which is sufficient for many spectroscopic applications, was realized in the low current 14 kV/0.02 A regime. The possibility of frequency tuning by variation of the coolant temperature about 4 MHz/1 °C was demonstrated. The spectral width of the gyrotron radiation was about 10(-6).
Collapse
Affiliation(s)
- M Yu Glyavin
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - A V Chirkov
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - G G Denisov
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - A P Fokin
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - V V Kholoptsev
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - A N Kuftin
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - A G Luchinin
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - G Yu Golubyatnikov
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - V I Malygin
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - M V Morozkin
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - V N Manuilov
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - M D Proyavin
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - A S Sedov
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | | | - E M Tai
- Gycom Ltd., Nizhny Novgorod, Russia
| | - A I Tsvetkov
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - V E Zapevalov
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| |
Collapse
|
30
|
Enkin N, Liu G, Gimenez-Lopez MDC, Porfyrakis K, Tkach I, Bennati M. A high saturation factor in Overhauser DNP with nitroxide derivatives: the role of 14N nuclear spin relaxation. Phys Chem Chem Phys 2015; 17:11144-9. [DOI: 10.1039/c5cp00935a] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Functionalization of nitroxide radicals leads to an increase of the saturation factor and of the Overhauser DNP enhancement.
Collapse
Affiliation(s)
- Nikolay Enkin
- RG EPR spectroscopy
- Max-Planck Institute for Biophysical Chemistry
- 37077 Göttingen
- Germany
| | - Guoquan Liu
- RG EPR spectroscopy
- Max-Planck Institute for Biophysical Chemistry
- 37077 Göttingen
- Germany
| | | | | | - Igor Tkach
- RG EPR spectroscopy
- Max-Planck Institute for Biophysical Chemistry
- 37077 Göttingen
- Germany
| | - Marina Bennati
- RG EPR spectroscopy
- Max-Planck Institute for Biophysical Chemistry
- 37077 Göttingen
- Germany
- Department of Chemistry
| |
Collapse
|
31
|
Jakdetchai O, Denysenkov V, Becker-Baldus J, Dutagaci B, Prisner TF, Glaubitz C. Dynamic nuclear polarization-enhanced NMR on aligned lipid bilayers at ambient temperature. J Am Chem Soc 2014; 136:15533-6. [PMID: 25333422 DOI: 10.1021/ja509799s] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Dynamic nuclear polarization (DNP)-enhanced solid-state NMR spectroscopy has been shown to hold great potential for functional studies of membrane proteins at low temperatures due to its great sensitivity improvement. There are, however, numerous applications for which experiments at ambient temperature are desirable and which would also benefit from DNP signal enhancement. Here, we demonstrate as a proof of concept that a significant signal increase for lipid bilayers under room-temperature conditions can be achieved by utilizing the Overhauser effect. Experiments were carried out on aligned bilayers at 400 MHz/263 GHz using a stripline structure combined with a Fabry-Perot microwave resonator. A signal enhancement of protons of up to -10 was observed. Our results demonstrate that Overhauser DNP at high field provides efficient polarization transfer within insoluble samples, which is driven by fast local molecular fluctuations. Furthermore, our experimental setup offers an attractive option for DNP-enhanced solid-state NMR on ordered membranes and provides a general perspective toward DNP at ambient temperatures.
Collapse
Affiliation(s)
- Orawan Jakdetchai
- Institute of Biophysical Chemistry and ‡Institute of Physical and Theoretical Chemistry, Center for Biomolecular Magnetic Resonance Frankfurt, Goethe University Frankfurt , 60438 Frankfurt am Main, Germany
| | | | | | | | | | | |
Collapse
|
32
|
Zotova IV, Ginzburg NS, Sergeev AS, Kocharovskaya ER, Zaslavsky VY. Conversion of an electromagnetic wave into a periodic train of solitons under cyclotron resonance interaction with a backward beam of unexcited electron-oscillators. PHYSICAL REVIEW LETTERS 2014; 113:143901. [PMID: 25325645 DOI: 10.1103/physrevlett.113.143901] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Indexed: 06/04/2023]
Abstract
The possibility of the conversion of intense continuous microwave radiation into a periodic train of short pulses by means of resonant interaction with a beam of unexcited cyclotron electron oscillators moving backward is shown. In such a system there is a certain range of parameters where the incident stationary signal splits into a train of short pulses and each of them can be interpreted as a soliton. It is proposed to use this effect for amplitude modulation of radiation of short wavelength gyrotrons.
Collapse
Affiliation(s)
- I V Zotova
- Institute of Applied Physics RAS, GSP-120 Nizhny Novgorod, Russia
| | - N S Ginzburg
- Institute of Applied Physics RAS, GSP-120 Nizhny Novgorod, Russia and Nizhny Novgorod State University, 603950 Nizhny Novgorod, Russia
| | - A S Sergeev
- Institute of Applied Physics RAS, GSP-120 Nizhny Novgorod, Russia
| | | | - V Yu Zaslavsky
- Institute of Applied Physics RAS, GSP-120 Nizhny Novgorod, Russia and Nizhny Novgorod State University, 603950 Nizhny Novgorod, Russia
| |
Collapse
|
33
|
van der Heijden GHA, Kentgens APM, van Bentum PJM. Liquid state dynamic nuclear polarization of ethanol at 3.4 T (95 GHz). Phys Chem Chem Phys 2014; 16:8493-502. [PMID: 24668422 DOI: 10.1039/c3cp55254c] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Dynamic Nuclear Polarization (DNP) in the liquid state has become the focus of attention to improve the NMR sensitivity of mass limited samples. The Overhauser model predicts a fast reduction in DNP enhancement at high magnetic fields where the electron Larmor frequency exceeds the typical inverse correlation time of the magnetic interaction between an unpaired electron spin of a radical and proton spins of the solvent molecules. The Overhauser hard sphere model is able to predict quantitatively the DNP enhancement for water TEMPOL solutions. The increase in temperature due to dielectric heating of the sample acts to reduce the correlation times and allows a substantial Overhauser DNP. In this paper we extend the work done on water towards other small molecules, such as ethanol. Experimentally we observe a similar enhancement for all three proton groups in the ethanol molecule. The classical interpretation of the low field Overhauser experiments on ethanol invokes a very fast anisotropic rotation of the hydrogen bonded TEMPOL-ethanol complex to explain the fast relaxation of the OH proton. Here we will discuss W-band relaxation and DNP enhancement within this classical model. Although the description can be made quantitative, the invoked parameters do not seem to be realistic. We will propose an alternative model based on the dynamic interaction both in free collision and due to modulation of the hydrogen bond length of the complex.
Collapse
Affiliation(s)
- G H A van der Heijden
- Institute for Molecules and Materials, Radboud University Nijmegen, P.O. Box 9010, 6500 GL Nijmegen, The Netherlands.
| | | | | |
Collapse
|
34
|
Luchinat C, Parigi G, Ravera E. Can metal ion complexes be used as polarizing agents for solution DNP? A theoretical discussion. JOURNAL OF BIOMOLECULAR NMR 2014; 58:239-249. [PMID: 23606273 DOI: 10.1007/s10858-013-9728-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2012] [Accepted: 04/05/2013] [Indexed: 06/02/2023]
Abstract
Dynamic nuclear polarization (DNP) can be used to dramatically increase the NMR signal intensities in solutions and solids. DNP is usually performed using nitroxide radicals as polarizing agents, characterized by sharp EPR lines, fast rotation, fast diffusion, and favorable distribution of the unpaired electron. These features make the nitroxide radicals ideally suited for solution DNP. Here, we report some theoretical considerations on the different behavior of some inorganic compounds with respect to nitroxide radicals. The relaxation profiles of slow relaxing paramagnetic metal aqua ions [copper(II), manganese(II), gadolinium(III) and oxovanadium(IV)] and complexes have been re-analyzed according to the standard theory for dipolar and contact relaxation, in order to estimate the coupling factor responsible for the maximum DNP enhancement that can be achieved in solution and its dependence on field, temperature and relative importance of outer-sphere versus inner-sphere relaxation.
Collapse
Affiliation(s)
- Claudio Luchinat
- CERM, University of Florence, Via Luigi Sacconi 6, 50019, Sesto Fiorentino, Italy,
| | | | | |
Collapse
|
35
|
Lee JH, Okuno Y, Cavagnero S. Sensitivity enhancement in solution NMR: emerging ideas and new frontiers. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2014; 241:18-31. [PMID: 24656077 PMCID: PMC3967054 DOI: 10.1016/j.jmr.2014.01.005] [Citation(s) in RCA: 114] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Revised: 01/14/2014] [Accepted: 01/17/2014] [Indexed: 05/05/2023]
Abstract
Modern NMR spectroscopy has reached an unprecedented level of sophistication in the determination of biomolecular structure and dynamics at atomic resolution in liquids. However, the sensitivity of this technique is still too low to solve a variety of cutting-edge biological problems in solution, especially those that involve viscous samples, very large biomolecules or aggregation-prone systems that need to be kept at low concentration. Despite the challenges, a variety of efforts have been carried out over the years to increase sensitivity of NMR spectroscopy in liquids. This review discusses basic concepts, recent developments and future opportunities in this exciting area of research.
Collapse
Affiliation(s)
- Jung Ho Lee
- Department of Chemistry and Biophysics Program, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706-1322, USA
| | - Yusuke Okuno
- Department of Chemistry and Biophysics Program, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706-1322, USA
| | - Silvia Cavagnero
- Department of Chemistry and Biophysics Program, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706-1322, USA.
| |
Collapse
|
36
|
Valentine K, Mathies G, Bédard S, Nucci NV, Dodevski I, Stetz MA, Can TV, Griffin RG, Wand AJ. Reverse micelles as a platform for dynamic nuclear polarization in solution NMR of proteins. J Am Chem Soc 2014; 136:2800-7. [PMID: 24456213 PMCID: PMC3955360 DOI: 10.1021/ja4107176] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2013] [Indexed: 02/06/2023]
Abstract
Despite tremendous advances in recent years, solution NMR remains fundamentally restricted due to its inherent insensitivity. Dynamic nuclear polarization (DNP) potentially offers significant improvements in this respect. The basic DNP strategy is to irradiate the EPR transitions of a stable radical and transfer this nonequilibrium polarization to the hydrogen spins of water, which will in turn transfer polarization to the hydrogens of the macromolecule. Unfortunately, these EPR transitions lie in the microwave range of the electromagnetic spectrum where bulk water absorbs strongly, often resulting in catastrophic heating. Furthermore, the residence times of water on the surface of the protein in bulk solution are generally too short for efficient transfer of polarization. Here we take advantage of the properties of solutions of encapsulated proteins dissolved in low viscosity solvents to implement DNP in liquids. Such samples are largely transparent to the microwave frequencies required and thereby avoid significant heating. Nitroxide radicals are introduced into the reverse micelle system in three ways: attached to the protein, embedded in the reverse micelle shell, and free in the aqueous core. Significant enhancements of the water resonance ranging up to ∼-93 at 0.35 T were observed. We also find that the hydration properties of encapsulated proteins allow for efficient polarization transfer from water to the protein. These and other observations suggest that merging reverse micelle encapsulation technology with DNP offers a route to a significant increase in the sensitivity of solution NMR spectroscopy of proteins and other biomolecules.
Collapse
Affiliation(s)
- Kathleen
G. Valentine
- Johnson
Research Foundation and Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6059
| | - Guinevere Mathies
- Francis
Bitter Magnet Laboratory and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Sabrina Bédard
- Johnson
Research Foundation and Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6059
| | - Nathaniel V. Nucci
- Johnson
Research Foundation and Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6059
| | - Igor Dodevski
- Johnson
Research Foundation and Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6059
| | - Matthew A. Stetz
- Johnson
Research Foundation and Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6059
| | - Thach V. Can
- Francis
Bitter Magnet Laboratory and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Robert G. Griffin
- Francis
Bitter Magnet Laboratory and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - A. Joshua Wand
- Johnson
Research Foundation and Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6059
| |
Collapse
|
37
|
Mao J, Akhmetzyanov D, Ouari O, Denysenkov V, Corzilius B, Plackmeyer J, Tordo P, Prisner TF, Glaubitz C. Host-guest complexes as water-soluble high-performance DNP polarizing agents. J Am Chem Soc 2013; 135:19275-81. [PMID: 24279469 DOI: 10.1021/ja409840y] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Dynamic nuclear polarization (DNP) enhances the sensitivity of solid-state NMR (SSNMR) spectroscopy by orders of magnitude and, therefore, opens possibilities for novel applications from biology to materials science. This multitude of opportunities implicates a need for high-performance polarizing agents, which integrate specific physical and chemical features tailored for various applications. Here, we demonstrate that for the biradical bTbK in complex with captisol (CAP), a β-cyclodextrin derivative, host-guest assembling offers a new and easily accessible approach for the development of new polarizing agents. In contrast to bTbK, the CAP-bTbK complex is water-soluble and shows significantly improved DNP performance compared to the commonly used DNP agent TOTAPOL. Furthermore, NMR and EPR data reveal improved electron and nuclear spin relaxation properties for bTbK within the host molecule. The numerous possibilities to functionalize host molecules will permit designing novel radical complexes targeting diverse applications.
Collapse
Affiliation(s)
- Jiafei Mao
- Institutes of Biophysical Chemistry, ‡Physical and Theoretical Chemistry and §Center for Biomolecular Magnetic Resonance BMRZ, Goethe University Frankfurt , 60438 Frankfurt/M., Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Cheng CY, Han S. Dynamic Nuclear Polarization Methods in Solids and Solutions to Explore Membrane Proteins and Membrane Systems. Annu Rev Phys Chem 2013; 64:507-32. [DOI: 10.1146/annurev-physchem-040412-110028] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Membrane proteins regulate vital cellular processes, including signaling, ion transport, and vesicular trafficking. Obtaining experimental access to their structures, conformational fluctuations, orientations, locations, and hydration in membrane environments, as well as the lipid membrane properties, is critical to understanding their functions. Dynamic nuclear polarization (DNP) of frozen solids can dramatically boost the sensitivity of current solid-state nuclear magnetic resonance tools to enhance access to membrane protein structures in native membrane environments. Overhauser DNP in the solution state can map out the local and site-specific hydration dynamics landscape of membrane proteins and lipid membranes, critically complementing the structural and dynamics information obtained by electron paramagnetic resonance spectroscopy. Here, we provide an overview of how DNP methods in solids and solutions can significantly increase our understanding of membrane protein structures, dynamics, functions, and hydration in complex biological membrane environments.
Collapse
Affiliation(s)
- Chi-Yuan Cheng
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106
| | - Songi Han
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106
| |
Collapse
|
39
|
Neugebauer P, Krummenacker JG, Denysenkov VP, Parigi G, Luchinat C, Prisner TF. Liquid state DNP of water at 9.2 T: an experimental access to saturation. Phys Chem Chem Phys 2013; 15:6049-56. [PMID: 23493879 DOI: 10.1039/c3cp44461a] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have performed liquid state ("Overhauser") Dynamic Nuclear Polarization (DNP) experiments at high magnetic field (9.2 T, corresponding to 260 GHz EPR and 400 MHz (1)H-NMR resonance frequency) on aqueous solutions of (14)N-TEMPOL nitroxide radicals. Integrated signal enhancements exceeding -80 were observed for the water protons at microwave superheated temperatures (160 °C) and still -14 at ambient temperatures (45 °C) relevant to biological applications. Different contributions contributing to the DNP enhancement such as saturation factor, leakage factor and sample temperature under microwave irradiation could be determined independently for a high spin concentration of 1 M, allowing the calculation of the coupling factors as a function of temperature and a quantitative comparison of this parameter with values derived from field dependent relaxation measurements or predictions from MD simulation.
Collapse
Affiliation(s)
- Petr Neugebauer
- Institute of Physical and Theoretical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe-University, Max-von-Laue-Str. 7, 60438, Frankfurt am Main, Germany
| | | | | | | | | | | |
Collapse
|
40
|
Sezer D. Computation of DNP coupling factors of a nitroxide radical in toluene: seamless combination of MD simulations and analytical calculations. Phys Chem Chem Phys 2013; 15:526-40. [DOI: 10.1039/c2cp42430d] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
41
|
Jawla S, Ni QZ, Barnes A, Guss W, Daviso E, Herzfeld J, Griffin R, Temkin R. Continuously Tunable 250 GHz Gyrotron with a Double Disk Window for DNP-NMR Spectroscopy. JOURNAL OF INFRARED, MILLIMETER AND TERAHERTZ WAVES 2013; 34:42-52. [PMID: 23539422 PMCID: PMC3607393 DOI: 10.1007/s10762-012-9947-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
In this paper, we describe the design and experimental results from the rebuild of a 250 GHz gyrotron used for Dynamic Nuclear Polarization enhanced Nuclear Magnetic Resonance spectroscopy on a 380 MHz spectrometer. Tuning bandwidth of approximately 2 GHz is easily achieved at a fixed magnetic field of 9.24 T and a beam current of 95 mA producing an average output power of >10 W over the entire tuning band. This tube incorporates a double disk output sapphire window in order to maximize the transmission at 250.58 GHz. DNP Signal enhancement of >125 is achieved on a 13C-Urea sample using this gyrotron.
Collapse
Affiliation(s)
- Sudheer Jawla
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA-02139, USA
| | - Qing Zhe Ni
- Francis Bitter Magnet Lab and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA-02139, USA
| | - Alexander Barnes
- Francis Bitter Magnet Lab and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA-02139, USA
| | - William Guss
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA-02139, USA
| | - Eugenio Daviso
- Francis Bitter Magnet Lab and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA-02139, USA
- Department of Chemistry, Brandies University, Waltham, MA-02454, USA
| | - Judith Herzfeld
- Department of Chemistry, Brandies University, Waltham, MA-02454, USA
| | - Robert Griffin
- Francis Bitter Magnet Lab and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA-02139, USA
| | - Richard Temkin
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA-02139, USA
| |
Collapse
|
42
|
Abstract
Nuclear magnetic resonance (NMR) spectroscopy is one of the most commonly used spectroscopic techniques to obtain information on the structure and dynamics of biological and chemical materials. A variety of samples can be studied including solutions, crystalline solids, powders and hydrated protein extracts. However, biological NMR spectroscopy is limited to concentrated samples, typically in the millimolar range, due to its intrinsic low sensitivity compared to other techniques such as fluorescence or electron paramagnetic resonance (EPR) spectroscopy.Dynamic nuclear polarization (DNP) is a method that increases the sensitivity of NMR by several orders of magnitude. It exploits a polarization transfer from unpaired electrons to neighboring nuclei which leads to an absolute increase of the signal-to-noise ratio (S/N). Consequently, biological samples with much lower concentrations can now be studied in hours or days compared to several weeks.This chapter will explain the different types of DNP enhanced NMR experiments, focusing primarily on solid-state magic angle spinning (MAS) DNP, its applications, and possible means of improvement.
Collapse
|
43
|
Türke MT, Bennati M. Comparison of Overhauser DNP at 0.34 and 3.4 T with Frémy's Salt. APPLIED MAGNETIC RESONANCE 2012; 43:129-138. [PMID: 22815593 PMCID: PMC3396338 DOI: 10.1007/s00723-012-0362-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Revised: 05/11/2012] [Indexed: 05/05/2023]
Abstract
Dynamic nuclear polarization (DNP) is investigated in the liquid state using a model system of Frémy's salt dissolved in water. Nuclear magnetic resonance signal enhancements at 0.34 and 3.4 T of the bulk water protons are recorded as a function of the irradiation time and the polarizer concentration. The build-up rates are consistent with the T(1n) of the observed water protons at room temperature (for 9 GHz/0.34 T) and for about 50 ± 10 °C at 94 GHz/3.4 T. At 94 GHz/3.4 T, we observe in our setup a maximal enhancement of -50 at 25 mM polarizer concentration. The use of Frémy's salt allows the determination of the saturation factors at 94 GHz by pulsed ELDOR experiments. The results are well consistent with the Overhauser DNP mechanism and indicate that higher enhancements at this intermediate frequency require higher sample temperatures.
Collapse
Affiliation(s)
- M.-T. Türke
- Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - M. Bennati
- Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| |
Collapse
|
44
|
Denysenkov V, Prisner T. Liquid state Dynamic Nuclear Polarization probe with Fabry-Perot resonator at 9.2 T. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2012; 217:1-5. [PMID: 22386647 DOI: 10.1016/j.jmr.2012.01.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Revised: 01/23/2012] [Accepted: 01/25/2012] [Indexed: 05/31/2023]
Abstract
Recent achievements in liquid state DNP at high magnetic fields showing significant enhancements on aqueous solutions have initiated strong interest in possible applications of this method to biomolecular research. However, in situ DNP of biomolecules at ambient temperatures is a challenging task due to high microwave losses leading to excessive sample heating. To avoid such heating the sample volume has to be reduced strongly to keep it away from the electric component of the microwave field. A helical double resonance structure, used for the first demonstrations of the applicability of Overhauser DNP to aqueous solutions at high magnetic fields (9.2 T), restricted the sample size to a very small volume of 2 nl. Together with a poor spectral resolution this resulted in small overall signal amplitude, hampering observations of biomolecules. Here we present a new type of the double resonance structure for liquid-state DNP which consists of a Fabry-Perot resonator for the microwave excitation and a stripline resonator for the NMR detection. This new double resonance structure (260 GHz/400 MHz) offers a 30-fold increase in aqueous sample volume (80 nl) with respect to the helical probe and exhibits improved NMR sensitivity and linewidth.
Collapse
Affiliation(s)
- Vasyl Denysenkov
- Institute for Physical Chemistry, Goethe University Frankfurt, Max von Laue Str. 7, 60438 Frankfurt am Main, Germany
| | | |
Collapse
|
45
|
Türke MT, Parigi G, Luchinat C, Bennati M. Overhauser DNP with15N labelled Frémy's salt at 0.35 Tesla. Phys Chem Chem Phys 2012; 14:502-10. [DOI: 10.1039/c1cp22332a] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
46
|
Macor A, de Rijk E, Annino G, Alberti S, Ansermet JP. THz-waves channeling in a monolithic saddle-coil for Dynamic Nuclear Polarization enhanced NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2011; 212:440-449. [PMID: 21903436 DOI: 10.1016/j.jmr.2011.08.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Revised: 07/21/2011] [Accepted: 08/10/2011] [Indexed: 05/31/2023]
Abstract
A saddle coil manufactured by electric discharge machining (EDM) from a solid piece of copper has recently been realized at EPFL for Dynamic Nuclear Polarization enhanced Nuclear Magnetic Resonance experiments (DNP-NMR) at 9.4 T. The corresponding electromagnetic behavior of radio-frequency (400 MHz) and THz (263 GHz) waves were studied by numerical simulation in various measurement configurations. Moreover, we present an experimental method by which the results of the THz-wave numerical modeling are validated. On the basis of the good agreement between numerical and experimental results, we conducted by numerical simulation a systematic analysis on the influence of the coil geometry and of the sample properties on the THz-wave field, which is crucial in view of the optimization of DNP-NMR in solids.
Collapse
Affiliation(s)
- A Macor
- Institut de Physique de la Matire Condense, Ecole Polytechnique Fédérale de Lausanne, Station 3, CH-1015 Lausanne, Switzerland.
| | | | | | | | | |
Collapse
|
47
|
Banerjee D, Paniagua JC, Mugnaini V, Veciana J, Feintuch A, Pons M, Goldfarb D. Correlation of the EPR properties of perchlorotriphenylmethyl radicals and their efficiency as DNP polarizers. Phys Chem Chem Phys 2011; 13:18626-37. [PMID: 21946909 DOI: 10.1039/c1cp21970g] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Water soluble perchlorinated trityl (PTM) radicals were found to be effective 95 GHz DNP (dynamic nuclear polarization) polarizers in ex situ (dissolution) (13)C DNP (Gabellieri et al., Angew Chem., Int. Ed. 2010, 49, 3360). The degree of the nuclear polarization obtained was reported to be dependent on the position of the chlorine substituents on the trityl skeleton. In addition, on the basis of the DNP frequency sweeps it was suggested that the (13)C NMR signal enhancement is mediated by the Cl nuclei. To understand the DNP mechanism of the PTM radicals we have explored the 95 GHz EPR characteristics of these radicals that are relevant to their performance as DNP polarizers. The EPR spectra of the radicals revealed axially symmetric g-tensors. A comparison of the spectra with the (13)C DNP frequency sweeps showed that although the solid effect mechanism is operational the DNP frequency sweeps reveal some extra width suggesting that contributions from EPR forbidden transitions involving (35,37)Cl nuclear flips are likely. This was substantiated experimentally by ELDOR (electron-electron double resonance) detected NMR measurements, which map the EPR forbidden transitions, and ELDOR experiments that follow the depolarization of the electron spin upon irradiation of the forbidden EPR transitions. DFT (density functional theory) calculations helped to assign the observed transitions and provided the relevant spin Hamiltonian parameters. These results show that the (35,37)Cl hyperfine and nuclear quadrupolar interactions cause a considerable nuclear state mixing at 95 GHz thus facilitating the polarization of the Cl nuclei upon microwave irradiation. Overlap of Cl nuclear frequencies and the (13)C Larmor frequency further facilitates the polarization of the (13)C nuclei by spin diffusion. Calculation of the (13)C DNP frequency sweep based on the Cl nuclear polarization showed that it does lead to an increase in the width of the spectra, improving the agreement with the experimental sweeps, thus supporting the existence of a new heteronuclear assisted DNP mechanism.
Collapse
Affiliation(s)
- Debamalya Banerjee
- Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel
| | | | | | | | | | | | | |
Collapse
|
48
|
Nanni EA, Barnes AB, Griffin RG, Temkin RJ. THz Dynamic Nuclear Polarization NMR. IEEE TRANSACTIONS ON TERAHERTZ SCIENCE AND TECHNOLOGY 2011; 1:145-163. [PMID: 24639915 PMCID: PMC3955395 DOI: 10.1109/tthz.2011.2159546] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Dynamic nuclear polarization (DNP) increases the sensitivity of nuclear magnetic resonance (NMR) spectroscopy by using high frequency microwaves to transfer the polarization of the electrons to the nuclear spins. The enhancement in NMR sensitivity can amount to a factor of well above 100, enabling faster data acquisition and greatly improved NMR measurements. With the increasing magnetic fields (up to 23 T) used in NMR research, the required frequency for DNP falls into the THz band (140-600 GHz). Gyrotrons have been developed to meet the demanding specifications for DNP NMR, including power levels of tens of watts; frequency stability of a few megahertz; and power stability of 1% over runs that last for several days to weeks. Continuous gyrotron frequency tuning of over 1 GHz has also been demonstrated. The complete DNP NMR system must include a low loss transmission line; an optimized antenna; and a holder for efficient coupling of the THz radiation to the sample. This paper describes the DNP NMR process and illustrates the THz systems needed for this demanding spectroscopic application. THz DNP NMR is a rapidly developing, exciting area of THz science and technology.
Collapse
Affiliation(s)
- Emilio A Nanni
- Department of Electrical Engineering and Computer Science, and the Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA 02139 USA ( )
| | - Alexander B Barnes
- Department of Chemistry, the Francis Bitter Magnet Laboratory, 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 ( )
| | - Richard J Temkin
- Department of Physics, and the Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA 02139 USA ( )
| |
Collapse
|
49
|
|
50
|
van Bentum PJM, van der Heijden GHA, Villanueva-Garibay JA, Kentgens APM. Quantitative analysis of high field liquid state dynamic nuclear polarization. Phys Chem Chem Phys 2011; 13:17831-40. [DOI: 10.1039/c1cp22002k] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
|