1
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Zachrdla M, Turhan E, Pötzl C, Sadet A, Vasos PR, Kurzbach D. Hyperpolarized nuclear Overhauser enhancement of alanine methyl groups by doubly relayed proton exchange. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2024; 364:107727. [PMID: 38941676 DOI: 10.1016/j.jmr.2024.107727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 06/03/2024] [Accepted: 06/20/2024] [Indexed: 06/30/2024]
Abstract
Hyperpolarized water in dissolution dynamic nuclear polarization (dDNP) experiments has emerged as a promising method for enhancing nuclear magnetic resonance (NMR) signals, particularly in studies of proteins and peptides. Herein, we focus on the application of "proton exchange-doubly relayed" nuclear Overhauser effects (NOE) from hyperpolarized water to achieve positive signal enhancement of methyl groups in the side chain of an alanine-glycine peptide. In particular, we show a cascade hyperpolarization transfer. Initial proton exchange between solvent and amide introduces hyperpolarization into the peptide. Subsequently, intermolecular NOE relays the hyperpolarization first to Ala-Hα and then in a second step to the Ala-CH3 moiety. Both NOEs have negative signs. Hence, the twice-relayed NOE pathway leads to a positive signal enhancement of the methyl group with respect to the thermal equilibrium magnetization. This effect might indicate a way towards hyperpolarized water-based signal enhancement for methyl groups, which are often used for NMR studies of large proteins in solution.
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Affiliation(s)
- Milan Zachrdla
- Institute of Biological Chemistry, Faculty of Chemistry, University of Vienna, Währinger Str. 38, 1090 Vienna, Austria.
| | - Ertan Turhan
- Institute of Biological Chemistry, Faculty of Chemistry, University of Vienna, Währinger Str. 38, 1090 Vienna, Austria; University of Vienna, Vienna Doctoral School in Chemistry (DoSChem), Währinger Str. 42, 1090 Vienna, Austria
| | - Christopher Pötzl
- Institute of Biological Chemistry, Faculty of Chemistry, University of Vienna, Währinger Str. 38, 1090 Vienna, Austria; University of Vienna, Vienna Doctoral School in Chemistry (DoSChem), Währinger Str. 42, 1090 Vienna, Austria
| | - Aude Sadet
- Institute of Biological Chemistry, Faculty of Chemistry, University of Vienna, Währinger Str. 38, 1090 Vienna, Austria; Biophysics and Biomedical Applications Laboratory and Group, LGED, Extreme Light Infrastructure-Nuclear Physics, "Horia Hulubei" National Institute for Physics and Nuclear Engineering IFIN-HH, Reactorului Street, No. 30, 077125 Bucharest-Magurele, Romania
| | - Paul R Vasos
- Institute of Biological Chemistry, Faculty of Chemistry, University of Vienna, Währinger Str. 38, 1090 Vienna, Austria; Biophysics and Biomedical Applications Laboratory and Group, LGED, Extreme Light Infrastructure-Nuclear Physics, "Horia Hulubei" National Institute for Physics and Nuclear Engineering IFIN-HH, Reactorului Street, No. 30, 077125 Bucharest-Magurele, Romania; University of Bucharest, Interdisciplinary School for Doctoral Studies (ISDS), 36-46 Bd Kogalniceanu, RO-050107 Bucharest, Romania
| | - Dennis Kurzbach
- Institute of Biological Chemistry, Faculty of Chemistry, University of Vienna, Währinger Str. 38, 1090 Vienna, Austria
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2
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Teleanu F, Hanganu A, Tuta C, Sadet A, Voda MA, Vasos PR. Multiple Stroboscopic Detection of Long-Lived Nuclear Magnetization for Glutathione Oxidation Kinetics. J Phys Chem Lett 2023; 14:4247-4251. [PMID: 37126581 DOI: 10.1021/acs.jpclett.2c03924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Imaging the molecular kinetics of antioxidants by magnetic resonance can contribute to the mechanistic understanding of therapeutic approaches. Magnetic resonance detection of the response to flashes of oxidative stress requires sequential spectroscopy on the same time scale on which reactive oxygen species are generated. To this effect, we propose a single-polarization multiple-detection stroboscopic experiment. We demonstrate this experiment for the follow-up of glutathione oxidation kinetics. On-the-fly stroboscopic detection minimizes the durations necessary for single acquisitions yet necessitates sustaining of magnetization lifetimes. Long-lived proton spin states (LLS) in the cysteine and glycine residues of glutathione with TLLS up to 16 s are reached. Based on 1H LLS, we followed fast oxidation kinetics in the glutathione redox pair GSH/GSSG. This new detection method allows sampling of long-lived spin order multiple times via small flip-angle excitations. This establishes the ground for the follow-up of redox processes detecting GSH/GSSG kinetics as magnetic-resonance biomarker of FLASH oxidative processes on time scales of tens of seconds.
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Affiliation(s)
- Florin Teleanu
- Biophysics and Biomedical Applications Laboratory and Group, LGED, ELI-NP, Extreme Light Infrastructure-Nuclear Physics, "Horia Hulubei" National Institute for Physics and Nuclear Engineering IFIN-HH, Reactorului Street, no. 30, 077125 Bucharest-Magurele, Romania
| | - Anamaria Hanganu
- "C. D. Nenitzescu" Institute of Organic and Supramolecular Chemistry of the Romanian Academy, ICOS, Romanian Academy, Spl. Independentei 202B, 060023 Bucharest, Romania
| | - Catalin Tuta
- "Horia Hulubei" National Institute for Physics and Nuclear Engineering IFIN-HH, DRMR, Reactorului Street, no. 30, 077125 Bucharest-Magurele, Romania
| | - Aude Sadet
- Biophysics and Biomedical Applications Laboratory and Group, LGED, ELI-NP, Extreme Light Infrastructure-Nuclear Physics, "Horia Hulubei" National Institute for Physics and Nuclear Engineering IFIN-HH, Reactorului Street, no. 30, 077125 Bucharest-Magurele, Romania
| | - Mihai A Voda
- Biophysics and Biomedical Applications Laboratory and Group, LGED, ELI-NP, Extreme Light Infrastructure-Nuclear Physics, "Horia Hulubei" National Institute for Physics and Nuclear Engineering IFIN-HH, Reactorului Street, no. 30, 077125 Bucharest-Magurele, Romania
| | - Paul R Vasos
- Biophysics and Biomedical Applications Laboratory and Group, LGED, ELI-NP, Extreme Light Infrastructure-Nuclear Physics, "Horia Hulubei" National Institute for Physics and Nuclear Engineering IFIN-HH, Reactorului Street, no. 30, 077125 Bucharest-Magurele, Romania
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3
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Epasto LM, Honegger P, Che K, Kozak F, Jörg F, Schröder C, Kurzbach D. Nuclear Overhauser spectroscopy in hyperpolarized water - chemical vs. magnetic exchange. Chem Commun (Camb) 2022; 58:11661-11664. [PMID: 36169286 PMCID: PMC9578288 DOI: 10.1039/d2cc03735a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 09/21/2022] [Indexed: 11/29/2022]
Abstract
Dissolution dynamic nuclear polarization (dDNP) is a versatile hyperpolarization technique to boost signal intensities in nuclear magnetic resonance (NMR) spectroscopy. The possibility to dissolve biomolecules in a hyperpolarized aqueous buffer under mild conditions has recently widened the scope of NMR by dDNP. The water-to-target hyperpolarization transfer mechanisms remain yet unclear, not least due to an often-encountered dilemma of dDNP experiments: The strongly enhanced signal intensities are accompanied by limited structural information as data acquisition is restricted to short time series of only one-dimensional spectra or a single correlation spectrum. Tackling this challenge, we combine dDNP with molecular dynamics (MD) simulations and predictions of cross-relaxation rates to unravel the spin dynamics of magnetization flow in hyperpolarized solutions.
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Affiliation(s)
- Ludovica Martina Epasto
- University of Vienna, Faculty of Chemistry, Department of Biological Chemistry, Währingerstr. 38, 1090 Vienna, Austria.
- University of Vienna, Doctoral School in Chemistry (DoSChem), Währingerstr. 42, 1090 Vienna, Austria
| | - Philipp Honegger
- University of Vienna, Faculty of Chemistry, Department of Computational Biological Chemistry, Währingerstr. 17, 1090 Vienna, Austria
- Department of Systems Biology, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA
| | - Kateryna Che
- University of Vienna, Faculty of Chemistry, Department of Biological Chemistry, Währingerstr. 38, 1090 Vienna, Austria.
| | - Fanny Kozak
- University of Vienna, Faculty of Chemistry, Department of Biological Chemistry, Währingerstr. 38, 1090 Vienna, Austria.
- University of Vienna, Doctoral School in Chemistry (DoSChem), Währingerstr. 42, 1090 Vienna, Austria
| | - Florian Jörg
- University of Vienna, Doctoral School in Chemistry (DoSChem), Währingerstr. 42, 1090 Vienna, Austria
- University of Vienna, Faculty of Chemistry, Department of Computational Biological Chemistry, Währingerstr. 17, 1090 Vienna, Austria
| | - Christian Schröder
- University of Vienna, Faculty of Chemistry, Department of Computational Biological Chemistry, Währingerstr. 17, 1090 Vienna, Austria
| | - Dennis Kurzbach
- University of Vienna, Faculty of Chemistry, Department of Biological Chemistry, Währingerstr. 38, 1090 Vienna, Austria.
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4
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Negroni M, Guarin D, Che K, Epasto LM, Turhan E, Selimović A, Kozak F, Cousin S, Abergel D, Bodenhausen G, Kurzbach D. Inversion of Hyperpolarized 13C NMR Signals through Cross-Correlated Cross-Relaxation in Dissolution DNP Experiments. J Phys Chem B 2022; 126:4599-4610. [PMID: 35675502 PMCID: PMC9234958 DOI: 10.1021/acs.jpcb.2c03375] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Revised: 05/25/2022] [Indexed: 11/29/2022]
Abstract
Dissolution dynamic nuclear polarization (DDNP) is a versatile tool to boost signal amplitudes in solution-state nuclear magnetic resonance (NMR) spectroscopy. For DDNP, nuclei are spin-hyperpolarized "ex situ" in a dedicated DNP device and then transferred to an NMR spectrometer for detection. Dramatic signal enhancements can be achieved, enabling shorter acquisition times, real-time monitoring of fast reactions, and reduced sample concentrations. Here, we show how the sample transfer in DDNP experiments can affect NMR spectra through cross-correlated cross-relaxation (CCR), especially in the case of low-field passages. Such processes can selectively invert signals of 13C spins in proton-carrying moieties. For their investigations, we use schemes for simultaneous or "parallel" detection of hyperpolarized 1H and 13C nuclei. We find that 1H → 13C CCR can invert signals of 13C spins if the proton polarization is close to 100%. We deduce that low-field passage in a DDNP experiment, a common occurrence due to the introduction of so-called "ultra-shielded" magnets, accelerates these effects due to field-dependent paramagnetic relaxation enhancements that can influence CCR. The reported effects are demonstrated for various molecules, laboratory layouts, and DDNP systems. As coupled 13C-1H spin systems are ubiquitous, we expect similar effects to be observed in various DDNP experiments. This might be exploited for selective spectroscopic labeling of hydrocarbons.
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Affiliation(s)
- Mattia Negroni
- Faculty
of Chemistry, Institute of Biological Chemistry, University Vienna, Währinger
Str. 38, 1090 Vienna, Austria
| | - David Guarin
- Athinoula
A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, Massachusetts 02129, United States
- Polarize
ApS, 1808 Frederiksberg, Denmark
| | - Kateryna Che
- Faculty
of Chemistry, Institute of Biological Chemistry, University Vienna, Währinger
Str. 38, 1090 Vienna, Austria
| | - Ludovica M. Epasto
- Faculty
of Chemistry, Institute of Biological Chemistry, University Vienna, Währinger
Str. 38, 1090 Vienna, Austria
| | - Ertan Turhan
- Faculty
of Chemistry, Institute of Biological Chemistry, University Vienna, Währinger
Str. 38, 1090 Vienna, Austria
| | - Albina Selimović
- Faculty
of Chemistry, Institute of Biological Chemistry, University Vienna, Währinger
Str. 38, 1090 Vienna, Austria
| | - Fanny Kozak
- Faculty
of Chemistry, Institute of Biological Chemistry, University Vienna, Währinger
Str. 38, 1090 Vienna, Austria
| | - Samuel Cousin
- Institut
de Chimie Radicalaire—UMR 7273, Saint-Jérôme
Campus, Av. Esc. Normandie Niemen, Aix-Marseille Université/CNRS, 13397 Marseille
Cedex 20, France
| | - Daniel Abergel
- Laboratoire
des Biomolécules, LBM, Département de chimie, École
Normale Supérieure, PSL University, Sorbonne Université,
CNRS, 24 rue Lhomond, 75005 Paris, France
| | - Geoffrey Bodenhausen
- Laboratoire
des Biomolécules, LBM, Département de chimie, École
Normale Supérieure, PSL University, Sorbonne Université,
CNRS, 24 rue Lhomond, 75005 Paris, France
| | - Dennis Kurzbach
- Faculty
of Chemistry, Institute of Biological Chemistry, University Vienna, Währinger
Str. 38, 1090 Vienna, Austria
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5
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Abstract
Thanks to recent improvements in NMR spectrometer hardware and pulse sequence design, modern 13C NMR has become a useful tool for biomolecular applications. The complete assignment of a protein can be accomplished by using 13C detected multinuclear experiments and it can provide unique information relevant for the study of a variety of different biomolecules including paramagnetic proteins and intrinsically disordered proteins. A wide range of NMR observables can be measured, concurring to the structural and dynamic characterization of a protein in isolation, as part of a larger complex, or even inside a living cell. We present the different properties of 13C with respect to 1H, which provide the rationale for the experiments developed and their application, the technical aspects that need to be faced, and the many experimental variants designed to address different cases. Application areas where these experiments successfully complement proton NMR are also described.
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Affiliation(s)
- Isabella C. Felli
- Department of Chemistry “Ugo
Schiff” and Magnetic Resonance Center, University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino (Florence), Italy
| | - Roberta Pierattelli
- Department of Chemistry “Ugo
Schiff” and Magnetic Resonance Center, University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino (Florence), Italy
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6
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Hilty C, Kurzbach D, Frydman L. Hyperpolarized water as universal sensitivity booster in biomolecular NMR. Nat Protoc 2022; 17:1621-1657. [PMID: 35546640 DOI: 10.1038/s41596-022-00693-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 02/25/2022] [Indexed: 11/09/2022]
Abstract
NMR spectroscopy is the only method to access the structural dynamics of biomolecules at high (atomistic) resolution in their native solution state. However, this method's low sensitivity has two important consequences: (i) typically experiments have to be performed at high concentrations that increase sensitivity but are not physiological, and (ii) signals have to be accumulated over long periods, complicating the determination of interaction kinetics on the order of seconds and impeding studies of unstable systems. Both limitations are of equal, fundamental relevance: non-native conditions are of limited pharmacological relevance, and the function of proteins, enzymes and nucleic acids often relies on their interaction kinetics. To overcome these limitations, we have developed applications that involve 'hyperpolarized water' to boost signal intensities in NMR of proteins and nucleic acids. The technique includes four stages: (i) preparation of the biomolecule in partially deuterated buffers, (ii) preparation of 'hyperpolarized' water featuring enhanced 1H NMR signals via cryogenic dynamic nuclear polarization, (iii) sudden melting of the cryogenic pellet and dissolution of the protein or nucleic acid in the hyperpolarized water (enabling spontaneous exchanges of protons between water and target) and (iv) recording signal-amplified NMR spectra targeting either labile 1H or neighboring 15N/13C nuclei in the biomolecule. Water in the ensuing experiments is used as a universal 'hyperpolarization' agent, rendering the approach versatile and applicable to any biomolecule possessing labile hydrogens. Thus, questions can be addressed, ranging from protein and RNA folding problems to resolving structure-function relationships of intrinsically disordered proteins to investigating membrane interactions.
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Affiliation(s)
- Christian Hilty
- Chemistry Department, Texas A&M University, College Station, TX, USA.
| | - Dennis Kurzbach
- Faculty of Chemistry, Institute for Biological Chemistry, University of Vienna, Vienna, Austria.
| | - Lucio Frydman
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel.
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7
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Lê TP, Hyacinthe JN, Capozzi A. How to improve the efficiency of a traditional dissolution dynamic nuclear polarization (dDNP) apparatus: Design and performance of a fluid path compatible dDNP/LOD-ESR probe. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2022; 338:107197. [PMID: 35344922 DOI: 10.1016/j.jmr.2022.107197] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 03/12/2022] [Accepted: 03/14/2022] [Indexed: 06/14/2023]
Abstract
Dissolution Dynamic Nuclear Polarization (dDNP) was invented almost twenty years ago. Ever since, hardware advancement has observed 2 trends: the quest for DNP at higher field and, more recently, the development of cryogen free polarizers. Despite the DNP community is slowly migrating towards "dry" systems, many "wet" polarizers are still in use. Traditional DNP polarizers can use up to 100 L of liquid helium per week, but are less sensitive to air contamination and have higher cooling power. These two characteristics make them very versatile when it comes to new methods development. In this study we retrofitted a 5 T/1.15 K "wet" DNP polarizer with the aim of improving cryogenic and DNP performance. We designed, built, and tested a new DNP insert that is compatible with the fluid path (FP) technology and a LOgitudinal Detected Electron Spin Resonance (LOD-ESR) probe to investigate radical properties at real DNP conditions. The new hardware increased the maximum achievable polarization and the polarization rate constant of a [1-13C]pyruvic acid-trityl sample by a factor 1.5. Moreover, the increased liquid He holding time together with the possibility to constantly keep the sample space at low pressure upon sample loading and dissolution allowed us to save about 20 L of liquid He per week.
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Affiliation(s)
- Thanh Phong Lê
- Geneva School of Health Sciences, HES-SO University of Applied Sciences and Arts Western Switzerland, Avenue de Champel 47, 1206 Geneva, Switzerland; LIFMET, Institute of Physics, École polytechnique fédérale de Lausanne (EPFL), Station 6, 1015 Lausanne, Switzerland
| | - Jean-Noël Hyacinthe
- Geneva School of Health Sciences, HES-SO University of Applied Sciences and Arts Western Switzerland, Avenue de Champel 47, 1206 Geneva, Switzerland; Image Guided Interventions Laboratory, Department of Radiology and Medical Informatics, University of Geneva, Rue Gabrielle-Perret-Gentil 4, 1211 Geneva, Switzerland
| | - Andrea Capozzi
- LIFMET, Institute of Physics, École polytechnique fédérale de Lausanne (EPFL), Station 6, 1015 Lausanne, Switzerland; HYPERMAG, Department of Health Technology, Technical University of Denmark, Building 349, 2800 Kgs Lyngby, Denmark.
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8
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Kouřil K, Gramberg M, Jurkutat M, Kouřilová H, Meier B. A cryogen-free, semi-automated apparatus for bullet-dynamic nuclear polarization with improved resolution. MAGNETIC RESONANCE (GOTTINGEN, GERMANY) 2021; 2:815-825. [PMID: 37905208 PMCID: PMC10539728 DOI: 10.5194/mr-2-815-2021] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 10/20/2021] [Indexed: 11/01/2023]
Abstract
In dissolution-dynamic nuclear polarization, a hyperpolarized solid is dissolved with a jet of hot solvent. The solution is then transferred to a secondary magnet, where spectra can be recorded with improved sensitivity. In bullet-dynamic nuclear polarization this order is reversed. Pressurized gas is used to rapidly transfer the hyperpolarized solid to the secondary magnet, and the hyperpolarized solid is dissolved only upon arrival. A potential advantage of this approach is that it may avoid excessive dilution and the associated signal loss, in particular for small sample quantities. Previously, we have shown that liquid-state NMR spectra with polarization levels of up to 30 % may be recorded within less than 1 s after the departure of the hyperpolarized solid from the polarizing magnet. The resolution of the recorded spectra however was limited. The system consumed significant amounts of liquid helium, and substantial manual work was required in between experiments to prepare for the next shot. Here, we present a new bullet-DNP (dynamic nuclear polarization) system that addresses these limitations.
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Affiliation(s)
- Karel Kouřil
- Institute for Biological Interfaces 4, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Michel Gramberg
- Institute for Biological Interfaces 4, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Michael Jurkutat
- Institute for Biological Interfaces 4, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Hana Kouřilová
- Institute for Biological Interfaces 4, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Benno Meier
- Institute for Biological Interfaces 4, Karlsruhe Institute of Technology, Karlsruhe, Germany
- Institute of Organic Chemistry, Karlsruhe Institute of Technology, Karlsruhe, Germany
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9
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Residue-resolved monitoring of protein hyperpolarization at sub-second time resolution. Commun Chem 2021; 4:147. [PMID: 36697662 PMCID: PMC9814832 DOI: 10.1038/s42004-021-00587-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 10/05/2021] [Indexed: 02/07/2023] Open
Abstract
Signal-enhancement techniques for NMR spectroscopy are important to amplify the weak resonances provided by nuclear spins. Recently, 'hyperpolarization' techniques have been intensively investigated. These provide nuclear spin states far from equilibrium yielding strong signal boosts up to four orders of magnitude. Here we propose a method for real-time NMR of 'hyperpolarized' proteins at residue resolution. The approach is based on dissolution dynamic nuclear polarization (d-DNP), which enables the use of hyperpolarized buffers that selectively boost NMR signals of solvent-exposed protein residues. The resulting spectral sparseness and signal enhancements enable recording of residue-resolved spectra at a 2 Hz sampling rate. Thus, we monitor the hyperpolarization level of different protein residues simultaneously under near-physiological conditions. We aim to address two points: 1) NMR experiments are often performed under conditions that increase sensitivity but are physiologically irrelevant; 2) long signal accumulation impedes fast real-time monitoring. Both limitations are of fundamental relevance to ascertain pharmacological relevance and study protein kinetics.
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10
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Felli IC, Bermel W, Pierattelli R. Exclusively heteronuclear NMR experiments for the investigation of intrinsically disordered proteins: focusing on proline residues. MAGNETIC RESONANCE (GOTTINGEN, GERMANY) 2021; 2:511-522. [PMID: 37904768 PMCID: PMC10539766 DOI: 10.5194/mr-2-511-2021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Accepted: 06/02/2021] [Indexed: 11/01/2023]
Abstract
NMR represents a key spectroscopic technique that contributes to the emerging field of highly flexible, intrinsically disordered proteins (IDPs) or protein regions (IDRs) that lack a stable three-dimensional structure. A set of exclusively heteronuclear NMR experiments tailored for proline residues, highly abundant in IDPs/IDRs, are presented here. They provide a valuable complement to the widely used approach based on amide proton detection, filling the gap introduced by the lack of amide protons in proline residues within polypeptide chains. The novel experiments have very interesting properties for the investigations of IDPs/IDRs of increasing complexity.
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Affiliation(s)
- Isabella C. Felli
- CERM and Department of Chemistry “Ugo Schiff”, University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Florence, Italy
| | - Wolfgang Bermel
- Bruker BioSpin GmbH, Silberstreifen 4, 76287 Rheinstetten, Germany
| | - Roberta Pierattelli
- CERM and Department of Chemistry “Ugo Schiff”, University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Florence, Italy
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11
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Kress T, Che K, Epasto L, Kozak F, Negroni M, Olsen G, Selimovic A, Kurzbach D. A novel sample handling system for dissolution dynamic nuclear polarization experiments. MAGNETIC RESONANCE (GOTTINGEN, GERMANY) 2021; 2:387-394. [PMID: 37904780 PMCID: PMC10539747 DOI: 10.5194/mr-2-387-2021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 05/19/2021] [Indexed: 11/01/2023]
Abstract
We present a system for facilitated sample vitrification, melting, and transfer in dissolution dynamic nuclear polarization (DDNP) experiments. In DDNP, a sample is typically hyperpolarized at cryogenic temperatures before dissolution with hot solvent and transfer to a nuclear magnetic resonance (NMR) spectrometer for detection in the liquid state. The resulting signal enhancements can exceed 4 orders of magnitude. However, the sudden temperature jump from cryogenic temperatures close to 1 K to ambient conditions imposes a particular challenge. It is necessary to rapidly melt the sample to avoid a prohibitively fast decay of hyperpolarization. Here, we demonstrate a sample dissolution method that facilitates the temperature jump by eliminating the need to open the cryostat used to cool the sample. This is achieved by inserting the sample through an airlock in combination with a dedicated dissolution system that is inserted through the same airlock shortly before the melting event. The advantages are threefold: (1) the cryostat can be operated continuously at low temperatures. (2) The melting process is rapid as no pressurization steps of the cryostat are required. (3) Blockages of the dissolution system due to freezing of solvents during melting and transfer are minimized.
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Affiliation(s)
- Thomas Kress
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road,
Cambridge CB2 1EW, UK
| | - Kateryna Che
- Faculty of Chemistry, Institute of Biological
Chemistry, University of Vienna, Währinger Str. 38, Vienna, Austria
| | - Ludovica M. Epasto
- Faculty of Chemistry, Institute of Biological
Chemistry, University of Vienna, Währinger Str. 38, Vienna, Austria
| | - Fanny Kozak
- Faculty of Chemistry, Institute of Biological
Chemistry, University of Vienna, Währinger Str. 38, Vienna, Austria
| | - Mattia Negroni
- Faculty of Chemistry, Institute of Biological
Chemistry, University of Vienna, Währinger Str. 38, Vienna, Austria
| | - Gregory L. Olsen
- Faculty of Chemistry, Institute of Biological
Chemistry, University of Vienna, Währinger Str. 38, Vienna, Austria
| | - Albina Selimovic
- Faculty of Chemistry, Institute of Biological
Chemistry, University of Vienna, Währinger Str. 38, Vienna, Austria
| | - Dennis Kurzbach
- Faculty of Chemistry, Institute of Biological
Chemistry, University of Vienna, Währinger Str. 38, Vienna, Austria
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12
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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] [MESH Headings] [Grants] [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.
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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
| | - Veronika Szalai
- National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
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13
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Kim J, Mandal R, Hilty C. 2D NMR spectroscopy of refolding RNase Sa using polarization transfer from hyperpolarized water. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2021; 326:106942. [PMID: 33713971 DOI: 10.1016/j.jmr.2021.106942] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 02/01/2021] [Accepted: 02/02/2021] [Indexed: 06/12/2023]
Abstract
Polarization transfer from hyperpolarized water through proton exchange is used to enhance the NMR signals of amide protons of the Ribonuclease Sa protein. Spectra of the refolding protein are measured within 6 s after dilution of the denaturant urea, at urea-dependent folding rates adjusted in the range of 0.3-0.8 s-1. Peak patterns including a mixture of folded and unfolded protein at different ratios are observed. The changes in the observed signals indicate that each spectrum accesses a different point in the partial completion of the folding. A comparison to simulated 2D NMR spectra suggests a lower polarization transfer efficiency from water when the protein folds slowly, which may result from the molecular motions in the unfolded protein and the absence of long-range contacts. The ability to acquire 2D NMR spectra under different refolding conditions may open a new avenue for residue specific characterization of the folding process.
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Affiliation(s)
- Jihyun Kim
- Chemistry Department, Texas A&M University, 3255 TAMU, College Station, TX 77843, USA
| | - Ratnamala Mandal
- Chemistry Department, Texas A&M University, 3255 TAMU, College Station, TX 77843, USA
| | - Christian Hilty
- Chemistry Department, Texas A&M University, 3255 TAMU, College Station, TX 77843, USA.
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14
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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: 24] [Impact Index Per Article: 6.0] [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.
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15
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Wang Y, Kim J, Hilty C. Determination of protein-ligand binding modes using fast multi-dimensional NMR with hyperpolarization. Chem Sci 2020; 11:5935-5943. [PMID: 32874513 PMCID: PMC7441707 DOI: 10.1039/d0sc00266f] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 05/05/2020] [Indexed: 11/21/2022] Open
Abstract
Elucidation of small molecule-protein interactions provides essential information for understanding biological processes such as cellular signaling, as well as for rational drug development. Here, multi-dimensional NMR with sensitivity enhancement by dissolution dynamic nuclear polarization (D-DNP) is shown to allow the determination of the binding epitope of folic acid when complexed with the target dihydrofolate reductase. Protein signals are selectively enhanced by polarization transfer from the hyperpolarized ligand. A pseudo three-dimensional data acquisition with ligand-side Hadamard encoding results in protein-side [13C, 1H] chemical shift correlations that contain intermolecular nuclear Overhauser effect (NOE) information. A scoring function based on this data is used to select pre-docked ligand poses. The top five poses are within 0.76 Å root-mean-square deviation from a reference structure for the encoded five protons, showing improvements compared with the poses selected by an energy-based scoring function without experimental inputs. The sensitivity enhancement provided by the D-DNP combined with multi-dimensional NMR increases the speed and potentially the selectivity of structure elucidation of ligand binding epitopes.
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Affiliation(s)
- Yunyi Wang
- Department of Chemistry , Texas A&M University , 3255 TAMU , College Station , TX 77843 , USA .
| | - Jihyun Kim
- Department of Chemistry , Texas A&M University , 3255 TAMU , College Station , TX 77843 , USA .
| | - Christian Hilty
- Department of Chemistry , Texas A&M University , 3255 TAMU , College Station , TX 77843 , USA .
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16
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Szekely O, Olsen GL, Novakovic M, Rosenzweig R, Frydman L. Assessing Site-Specific Enhancements Imparted by Hyperpolarized Water in Folded and Unfolded Proteins by 2D HMQC NMR. J Am Chem Soc 2020; 142:9267-9284. [PMID: 32338002 PMCID: PMC7304870 DOI: 10.1021/jacs.0c00807] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
![]()
Hyperpolarized water
can be a valuable aid in protein NMR, leading
to amide group 1H polarizations that are orders of magnitude
larger than their thermal counterparts. Suitable procedures can exploit
this to deliver 2D 1H–15N correlations
with good resolution and enhanced sensitivity. These enhancements
depend on the exchange rates between the amides and the water, thereby
yielding diagnostic information about solvent accessibility. This
study applied this “HyperW” method to four proteins
exhibiting a gamut of exchange behaviors: PhoA(350–471), an unfolded 122-residue fragment; barstar, a fully folded ribonuclease
inhibitor; R17, a 13.3 kDa system possessing folded and unfolded forms
under slow interconversion; and drkN SH3, a protein domain whose folded
and unfolded forms interchange rapidly and with temperature-dependent
population ratios. For PhoA4(350–471) HyperW sensitivity
enhancements were ≥300×, as expected for an unfolded protein
sequence. Though fully folded, barstar also exhibited substantial
enhancements; these, however, were not uniform and, according to CLEANEX
experiments, reflected the solvent-exposed residues. R17 showed the
expected superposition of ≥100-fold enhancements for its unfolded
form, coexisting with more modest enhancements for their folded counterparts.
Unexpected, however, was the behavior of drkN SH3, for which HyperW
enhanced the unfolded but, surprisingly, enhanced even more certain folded protein sites. These preferential enhancements were
repeatedly and reproducibly observed. A number of explanations—including
three-site exchange magnetization transfers between water and the
unfolded and folded states; cross-correlated relaxation processes
from hyperpolarized “structural” waters and labile side-chain
protons; and the possibility that faster solvent exchange rates characterize
certain folded sites over their unfolded counterparts—are considered
to account for them.
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17
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Pinon AC, Capozzi A, Ardenkjær-Larsen JH. Hyperpolarized water through dissolution dynamic nuclear polarization with UV-generated radicals. Commun Chem 2020; 3:57. [PMID: 36703471 PMCID: PMC9814647 DOI: 10.1038/s42004-020-0301-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 04/09/2020] [Indexed: 01/29/2023] Open
Abstract
In recent years, hyperpolarization of water protons via dissolution Dynamic Nuclear Polarization (dDNP) has attracted increasing interest in the magnetic resonance community. Hyperpolarized water may provide an alternative to Gd-based contrast agents for angiographic and perfusion Magnetic Resonance Imaging (MRI) examinations, and it may report on chemical and biochemical reactions and proton exchange while perfoming Nuclear Magnetic Resonance (NMR) investigations. However, hyperpolarizing water protons is challenging. The main reason is the presence of radicals, required to create the hyperpolarized nuclear spin state. Indeed, the radicals will also be the main source of relaxation during the dissolution and transfer to the NMR or MRI system. In this work, we report water magnetizations otherwise requiring a field of 10,000 T at room temperature on a sample of pure water, by employing dDNP via UV-generated, labile radicals. We demonstrate the potential of our methodology by acquiring a 15N spectrum from natural abundance urea with a single scan, after spontaneous magnetization transfer from water protons to nitrogen nuclei.
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Affiliation(s)
- Arthur C. Pinon
- grid.5170.30000 0001 2181 8870Center for Hyperpolarization in Magnetic Resonance, Department of Health Technology, Technical University of Denmark, Building 349, 2800 Kgs Lyngby, Denmark
| | - Andrea Capozzi
- grid.5170.30000 0001 2181 8870Center for Hyperpolarization in Magnetic Resonance, Department of Health Technology, Technical University of Denmark, Building 349, 2800 Kgs Lyngby, Denmark
| | - Jan Henrik Ardenkjær-Larsen
- grid.5170.30000 0001 2181 8870Center for Hyperpolarization in Magnetic Resonance, Department of Health Technology, Technical University of Denmark, Building 349, 2800 Kgs Lyngby, Denmark
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18
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Topping GJ, Hundshammer C, Nagel L, Grashei M, Aigner M, Skinner JG, Schulte RF, Schilling F. Acquisition strategies for spatially resolved magnetic resonance detection of hyperpolarized nuclei. MAGMA (NEW YORK, N.Y.) 2020; 33:221-256. [PMID: 31811491 PMCID: PMC7109201 DOI: 10.1007/s10334-019-00807-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 10/08/2019] [Accepted: 11/21/2019] [Indexed: 12/13/2022]
Abstract
Hyperpolarization is an emerging method in magnetic resonance imaging that allows nuclear spin polarization of gases or liquids to be temporarily enhanced by up to five or six orders of magnitude at clinically relevant field strengths and administered at high concentration to a subject at the time of measurement. This transient gain in signal has enabled the non-invasive detection and imaging of gas ventilation and diffusion in the lungs, perfusion in blood vessels and tissues, and metabolic conversion in cells, animals, and patients. The rapid development of this method is based on advances in polarizer technology, the availability of suitable probe isotopes and molecules, improved MRI hardware and pulse sequence development. Acquisition strategies for hyperpolarized nuclei are not yet standardized and are set up individually at most sites depending on the specific requirements of the probe, the object of interest, and the MRI hardware. This review provides a detailed introduction to spatially resolved detection of hyperpolarized nuclei and summarizes novel and previously established acquisition strategies for different key areas of application.
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Affiliation(s)
- Geoffrey J Topping
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Christian Hundshammer
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Luca Nagel
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Martin Grashei
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Maximilian Aigner
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Jason G Skinner
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | | | - Franz Schilling
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany.
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19
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Olsen GL, Szekely O, Mateos B, Kadeřávek P, Ferrage F, Konrat R, Pierattelli R, Felli IC, Bodenhausen G, Kurzbach D, Frydman L. Sensitivity-enhanced three-dimensional and carbon-detected two-dimensional NMR of proteins using hyperpolarized water. JOURNAL OF BIOMOLECULAR NMR 2020; 74:161-171. [PMID: 32040802 PMCID: PMC7080779 DOI: 10.1007/s10858-020-00301-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 01/27/2020] [Indexed: 05/11/2023]
Abstract
Signal enhancements of up to two orders of magnitude in protein NMR can be achieved by employing HDO as a vector to introduce hyperpolarization into folded or intrinsically disordered proteins. In this approach, hyperpolarized HDO produced by dissolution-dynamic nuclear polarization (D-DNP) is mixed with a protein solution waiting in a high-field NMR spectrometer, whereupon amide proton exchange and nuclear Overhauser effects (NOE) transfer hyperpolarization to the protein and enable acquisition of a signal-enhanced high-resolution spectrum. To date, the use of this strategy has been limited to 1D and 1H-15N 2D correlation experiments. Here we introduce 2D 13C-detected D-DNP, to reduce exchange-induced broadening and other relaxation penalties that can adversely affect proton-detected D-DNP experiments. We also introduce hyperpolarized 3D spectroscopy, opening the possibility of D-DNP studies of larger proteins and IDPs, where assignment and residue-specific investigation may be impeded by spectral crowding. The signal enhancements obtained depend in particular on the rates of chemical and magnetic exchange of the observed residues, thus resulting in non-uniform 'hyperpolarization-selective' signal enhancements. The resulting spectral sparsity, however, makes it possible to resolve and monitor individual amino acids in IDPs of over 200 residues at acquisition times of just over a minute. We apply the proposed experiments to two model systems: the compactly folded protein ubiquitin, and the intrinsically disordered protein (IDP) osteopontin (OPN).
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Affiliation(s)
- Gregory L Olsen
- Faculty of Chemistry, Institute for Biological Chemistry, University of Vienna, Währinger Straße 38, 1090, Vienna, Austria.
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel.
| | - Or Szekely
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Borja Mateos
- Department of Structural and Computational Biology, University of Vienna, Vienna BioCenter 5, 1030, Vienna, Austria
| | - Pavel Kadeřávek
- CEITEC-Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
- Laboratoire des biomolécules, LBM, Département de chimie, École normale supérieure, PSL University, Sorbonne Université, CNRS, 75005, Paris, France
| | - Fabien Ferrage
- Laboratoire des biomolécules, LBM, Département de chimie, École normale supérieure, PSL University, Sorbonne Université, CNRS, 75005, Paris, France
| | - Robert Konrat
- Department of Structural and Computational Biology, University of Vienna, Vienna BioCenter 5, 1030, Vienna, Austria
| | - Roberta Pierattelli
- Magnetic Resonance Center and Department of Chemistry Ugo Schiff, University of Florence, Via L. Sacconi 6, 50019, Sesto Fiorentino, FI, Italy
| | - Isabella C Felli
- Magnetic Resonance Center and Department of Chemistry Ugo Schiff, University of Florence, Via L. Sacconi 6, 50019, Sesto Fiorentino, FI, Italy
| | - Geoffrey Bodenhausen
- Laboratoire des biomolécules, LBM, Département de chimie, École normale supérieure, PSL University, Sorbonne Université, CNRS, 75005, Paris, France
| | - Dennis Kurzbach
- Faculty of Chemistry, Institute for Biological Chemistry, University of Vienna, Währinger Straße 38, 1090, Vienna, Austria.
- Laboratoire des biomolécules, LBM, Département de chimie, École normale supérieure, PSL University, Sorbonne Université, CNRS, 75005, Paris, France.
| | - Lucio Frydman
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel
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20
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A 300-fold enhancement of imino nucleic acid resonances by hyperpolarized water provides a new window for probing RNA refolding by 1D and 2D NMR. Proc Natl Acad Sci U S A 2020; 117:2449-2455. [PMID: 31949004 DOI: 10.1073/pnas.1916956117] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
NMR sensitivity-enhancement methods involving hyperpolarized water could be of importance for solution-state biophysical investigations. Hyperpolarized water (HyperW) can enhance the 1H NMR signals of exchangeable sites by orders of magnitude over their thermal counterparts, while providing insight into chemical exchange and solvent accessibility at a site-resolved level. As HyperW's enhancements are achieved by exploiting fast solvent exchanges associated with minimal interscan delays, possibilities for the rapid monitoring of chemical reactions and biomolecular (re)folding are opened. HyperW NMR can also accommodate heteronuclear transfers, facilitating the rapid acquisition of 2-dimensional (2D) 15N-1H NMR correlations, and thereby combining an enhanced spectral resolution with speed and sensitivity. This work demonstrates how these qualities can come together for the study of nucleic acids. HyperW injections were used to target the guanine-sensing riboswitch aptamer domain (GSRapt) of the xpt-pbuX operon in Bacillus subtilis Unlike what had been observed in proteins, where residues benefited of HyperW NMR only if/when sufficiently exposed to water, these enhancements applied to every imino resonance throughout the RNA. The >300-fold enhancements observed in the resulting 1H NMR spectra allowed us to monitor in real time the changes that GSRapt undergoes upon binding hypoxanthine, a high-affinity interaction leading to conformational refolding on a ∼1-s timescale at 36 °C. Structural responses could be identified for several nucleotides by 1-dimensional (1D) imino 1H NMR as well as by 2D HyperW NMR spectra acquired upon simultaneous injection of hyperpolarized water and hypoxanthine. The folding landscape revealed by this HyperW strategy for GSRapt, is briefly discussed.
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21
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Yang H, Hofstetter H, Cavagnero S. Fast-pulsing LED-enhanced NMR: A convenient and inexpensive approach to increase NMR sensitivity. J Chem Phys 2019; 151:245102. [PMID: 31893873 DOI: 10.1063/1.5131452] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Low-concentration photochemically induced dynamic nuclear polarization (LC-photo-CIDNP) has recently emerged as a powerful technology for the detection of aromatic amino acids and proteins in solution in the low-micromolar to nanomolar concentration range. LC-photo-CIDNP is typically carried out in the presence of high-power lasers, which are costly and maintenance-heavy. Here, we show that LC-photo-CIDNP can be performed with light-emitting diodes (LEDs), which are inexpensive and much less cumbersome than lasers, laser diodes, flash lamps, or other light sources. When nuclear magnetic resonance (NMR) sample concentration is within the low-micromolar to nanomolar range, as in LC-photo-CIDNP, replacement of lasers with LEDs leads to no losses in sensitivity. We also investigate the effect of optical-fiber thickness and compare excitation rate constants of an Ar ion laser (488 nm) and a 466 nm LED, taking LED emission bandwidths into account. In addition, importantly, we develop a novel pulse sequence (13C RASPRINT) to perform ultrarapid LC-photo-CIDNP data collection. Remarkably, 13C RASPRINT leads to 4-fold savings in data collection time. The latter advance relies on the fact that photo-CID nuclear hyperpolarization does not suffer from the longitudinal-relaxation recovery requirements of conventional NMR. Finally, we combine both the above improvements, resulting in facile and rapid (≈16 s-2.5 min) collection of 1 and 2D NMR data on aromatic amino acids and proteins in solution at nanomolar to low micromolar concentration.
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Affiliation(s)
- Hanming Yang
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706, USA
| | - Heike Hofstetter
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706, USA
| | - Silvia Cavagnero
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706, USA
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22
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Sadet A, Stavarache C, Teleanu F, Vasos PR. Water hydrogen uptake in biomolecules detected via nuclear magnetic phosphorescence. Sci Rep 2019; 9:17118. [PMID: 31745146 PMCID: PMC6864387 DOI: 10.1038/s41598-019-53558-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 10/16/2019] [Indexed: 11/27/2022] Open
Abstract
We introduce a new symmetry-based method for structural investigations of areas surrounding water-exchanging hydrogens in biomolecules by liquid-state nuclear magnetic resonance spectroscopy. Native structures of peptides and proteins can be solved by NMR with fair resolution, with the notable exception of labile hydrogen sites. The reason why biomolecular structures often remain elusive around exchangeable protons is that the dynamics of their exchange with the solvent hampers the observation of their signals. The new spectroscopic method we report allows to locate water-originating hydrogens in peptides and proteins via their effect on nuclear magnetic transitions similar to electronic phosphorescence, long-lived coherences. The sign of long-lived coherences excited in coupled protons can be switched by the experimenter. The different effect of water-exchanging hydrogens on long-lived coherences with opposed signs allows to pinpoint the position of these labile hydrogen atoms in the molecular framework of peptides and proteins.
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Affiliation(s)
- Aude Sadet
- Research Institute of the University of Bucharest (ICUB), 36-46 B-dul M. Kogalniceanu, RO-050107, Bucharest, Romania.,"Horia Hulubei" National Institute for Physics and Nuclear Engineering IFIN-HH, Extreme Light Infrastructure - Nuclear Physics ELI-NP, 30 Reactorului Street, RO-077125, Bucharest-Magurele, Romania
| | - Cristina Stavarache
- Research Institute of the University of Bucharest (ICUB), 36-46 B-dul M. Kogalniceanu, RO-050107, Bucharest, Romania.,"C. D. Nenitescu" Centre of Organic Chemistry, 202-B Spl. Independentei, RO-060023, Bucharest, Romania
| | - Florin Teleanu
- Research Institute of the University of Bucharest (ICUB), 36-46 B-dul M. Kogalniceanu, RO-050107, Bucharest, Romania.,Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Arany Janos 11, Cluj-Napoca, Romania.,"Horia Hulubei" National Institute for Physics and Nuclear Engineering IFIN-HH, Extreme Light Infrastructure - Nuclear Physics ELI-NP, 30 Reactorului Street, RO-077125, Bucharest-Magurele, Romania
| | - Paul R Vasos
- Research Institute of the University of Bucharest (ICUB), 36-46 B-dul M. Kogalniceanu, RO-050107, Bucharest, Romania. .,"Horia Hulubei" National Institute for Physics and Nuclear Engineering IFIN-HH, Extreme Light Infrastructure - Nuclear Physics ELI-NP, 30 Reactorului Street, RO-077125, Bucharest-Magurele, Romania.
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23
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Barskiy DA, Knecht S, Yurkovskaya AV, Ivanov KL. SABRE: Chemical kinetics and spin dynamics of the formation of hyperpolarization. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2019; 114-115:33-70. [PMID: 31779885 DOI: 10.1016/j.pnmrs.2019.05.005] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 05/16/2019] [Indexed: 05/22/2023]
Abstract
In this review, we present the physical principles of the SABRE (Signal Amplification By Reversible Exchange) method. SABRE is a promising hyperpolarization technique that enhances NMR signals by transferring spin order from parahydrogen (an isomer of the H2 molecule that is in a singlet nuclear spin state) to a substrate that is to be polarized. Spin order transfer takes place in a transient organometallic complex which binds both parahydrogen and substrate molecules; after dissociation of the SABRE complex, free hyperpolarized substrate molecules are accumulated in solution. An advantage of this method is that the substrate is not modified chemically, and its polarization can be regenerated multiple times by bubbling fresh parahydrogen through the solution. Thus, SABRE requires two key ingredients: (i) polarization transfer and (ii) chemical exchange of both parahydrogen and substrate. While there are several excellent reviews on applications of SABRE, the background of the method is discussed less frequently. In this review we aim to explain in detail how SABRE hyperpolarization is formed, focusing on key aspects of both spin dynamics and chemical kinetics, as well as on the interplay between them. Hence, we first cover the known spin order transfer methods applicable to SABRE - cross-relaxation, coherent spin mixing at avoided level crossings, and coherence transfer - and discuss their practical implementation for obtaining SABRE polarization in the most efficient way. Second, we introduce and explain the principle of SABRE hyperpolarization techniques that operate at ultralow (<1 μT), at low (1μT to 0.1 T) and at high (>0.1 T) magnetic fields. Finally, chemical aspects of SABRE are discussed in detail, including chemical systems that are amenable to SABRE and the exchange processes that are required for polarization formation. A theoretical treatment of the spin dynamics and their interplay with chemical kinetics is also presented. This review outlines known aspects of SABRE and provides guidelines for the design of new SABRE experiments, with the goal of solving practical problems of enhancing weak NMR signals.
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Affiliation(s)
- Danila A Barskiy
- Department of Chemistry, University of California at Berkeley, Berkeley, CA 94720, USA
| | - Stephan Knecht
- Eduard-Zintl Institute for Inorganic and Physical Chemistry, TU Darmstadt, Darmstadt 64287, Germany; Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Alexandra V Yurkovskaya
- International Tomography Center, Siberian Branch of the Russian Academy of Science, Novosibirsk 630090, Russia; Novosibirsk State University, Novosibirsk 630090, Russia
| | - Konstantin L Ivanov
- International Tomography Center, Siberian Branch of the Russian Academy of Science, Novosibirsk 630090, Russia; Novosibirsk State University, Novosibirsk 630090, Russia.
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24
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Kim J, Mandal R, Hilty C. Observation of Fast Two-Dimensional NMR Spectra during Protein Folding Using Polarization Transfer from Hyperpolarized Water. J Phys Chem Lett 2019; 10:5463-5467. [PMID: 31442055 DOI: 10.1021/acs.jpclett.9b02197] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Nuclear spin hyperpolarized water is utilized to obtain protein spectra not only in the folded state but also during the refolding process. Polarization transfer to Ribonuclease Sa through proton exchange and the nuclear Overhauser effect (NOE) results in NMR signal enhancements of amide protons by up to 24-fold. These enhancements enable the measurement of fast two-dimensional NMR spectra on the same time scale as the folding. Resolved amide proton signals corresponding to the folded protein are observed both under folded and refolding conditions, whereby the refolding protein shows smaller transferred signals. Residue-specific evaluation of contributions to the polarization transfer indicates that signals attributed to a relayed intramolecular NOE are not observable in the refolding experiment. These differences are explained by the absence of long-range contacts and faster molecular motions in the unfolded protein. Applications of this method include accessing residue-specific information on structure and dynamics during multistate protein folding.
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Affiliation(s)
- Jihyun Kim
- Chemistry Department , Texas A&M University , 3255 TAMU, College Station , Texas 77843 , United States
| | - Ratnamala Mandal
- Chemistry Department , Texas A&M University , 3255 TAMU, College Station , Texas 77843 , United States
| | - Christian Hilty
- Chemistry Department , Texas A&M University , 3255 TAMU, College Station , Texas 77843 , United States
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25
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Sadet A, Stavarache C, Bacalum M, Radu M, Bodenhausen G, Kurzbach D, Vasos PR. Hyperpolarized Water Enhances Two-Dimensional Proton NMR Correlations: A New Approach for Molecular Interactions. J Am Chem Soc 2019; 141:12448-12452. [PMID: 31368708 DOI: 10.1021/jacs.9b03651] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Protein and peptide interactions are characterized in the liquid state by multidimensional NMR spectroscopy experiments, which can take hours to record. We show that starting from hyperpolarized HDO, two-dimensional (2D) proton correlation maps of a peptide, either free in solution or interacting with liposomes, can be acquired in less than 60 s. In standard 2D NMR spectroscopy without hyperpolarization, the acquisition time required for similar spectral correlations is on the order of hours. This hyperpolarized experiment enables the identification of amino acids featuring solvent-interacting hydrogens and provides fast spectroscopic analysis of peptide conformers. Sensitivity-enhanced 2D proton correlation spectroscopy is a useful and straightforward tool for biochemistry and structural biology, as it does not recur to nitrogen-15 or carbon-13 isotope enrichment.
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Affiliation(s)
- Aude Sadet
- Research Institute of the University of Bucharest (ICUB) , 36-46 B-dul M. Kogalniceanu , RO-050107 Bucharest , Romania.,ELI-NP, Extreme Light Infrastructure - Nuclear Physics , IFIN-HH , 30 Reactorului Street , RO-077125 Bucharest-Magurele , Romania
| | - Cristina Stavarache
- Research Institute of the University of Bucharest (ICUB) , 36-46 B-dul M. Kogalniceanu , RO-050107 Bucharest , Romania.,"C.D. Nenitescu" Centre of Organic Chemistry , 202-B Spl. Independentei , RO-060023 Bucharest , Romania
| | - Mihaela Bacalum
- Department of Life and Environmental Physics , "Horia Hulubei" National Institute for Physics and Nuclear Engineering (IFIN-HH) , 30 Reactorului Street , RO-077125 Bucharest-Magurele , Romania
| | - Mihai Radu
- Department of Life and Environmental Physics , "Horia Hulubei" National Institute for Physics and Nuclear Engineering (IFIN-HH) , 30 Reactorului Street , RO-077125 Bucharest-Magurele , Romania
| | - Geoffrey Bodenhausen
- Laboratoire des Biomolécules, LBM, Département de Chimie , École Normale Supérieure, PSL University, Sorbonne Université, CNRS , 75005 Paris , France
| | - Dennis Kurzbach
- Laboratoire des Biomolécules, LBM, Département de Chimie , École Normale Supérieure, PSL University, Sorbonne Université, CNRS , 75005 Paris , France.,Institute of Biological Chemistry, Faculty of Chemistry , University of Vienna , Währinger Str. 38 , 1090 Vienna , Austria
| | - Paul R Vasos
- Research Institute of the University of Bucharest (ICUB) , 36-46 B-dul M. Kogalniceanu , RO-050107 Bucharest , Romania.,ELI-NP, Extreme Light Infrastructure - Nuclear Physics , IFIN-HH , 30 Reactorului Street , RO-077125 Bucharest-Magurele , Romania
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26
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Jannin S, Dumez JN, Giraudeau P, Kurzbach D. Application and methodology of dissolution dynamic nuclear polarization in physical, chemical and biological contexts. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2019; 305:41-50. [PMID: 31203098 PMCID: PMC6616036 DOI: 10.1016/j.jmr.2019.06.001] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 05/28/2019] [Accepted: 06/02/2019] [Indexed: 05/06/2023]
Abstract
Dissolution dynamic nuclear polarization (d-DNP) is a versatile method to enhance nuclear magnetic resonance (NMR) spectroscopy. It boosts signal intensities by four to five orders of magnitude thereby providing the potential to improve and enable a plethora of applications ranging from the real-time monitoring of chemical or biological processes to metabolomics and in-cell investigations. This perspectives article highlights possible avenues for developments and applications of d-DNP in biochemical and physicochemical studies. It outlines how chemists, biologists and physicists with various fields of interest can transform and employ d-DNP as a powerful characterization method for their research.
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Affiliation(s)
- Sami Jannin
- Université de Lyon, CNRS, Université Claude Bernard Lyon 1, ENS de Lyon, Centre de RMN à Très Hauts Champs (CRMN), FRE 2034, 69100 Villeurbanne, France
| | | | - Patrick Giraudeau
- Université de Nantes, CNRS, CEISAM (UMR 6230), 44000 Nantes, France; Institut Universitaire de France, 1 rue Descartes, 75005 Paris, France
| | - Dennis Kurzbach
- University of Vienna, Faculty of Chemistry, Institute of Biological Chemistry, Währinger Str. 38, 1090 Vienna, Austria.
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27
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Laser- and cryogenic probe-assisted NMR enables hypersensitive analysis of biomolecules at submicromolar concentration. Proc Natl Acad Sci U S A 2019; 116:11602-11611. [PMID: 31142651 DOI: 10.1073/pnas.1820573116] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Solution-state NMR typically requires 100 μM to 1 mM samples. This limitation prevents applications to mass-limited and aggregation-prone target molecules. Photochemically induced dynamic nuclear polarization was adapted to data collection on low-concentration samples by radiofrequency gating, enabling rapid 1D NMR spectral acquisition on aromatic amino acids and proteins bearing aromatic residues at nanomolar concentration, i.e., a full order of magnitude below other hyperpolarization techniques in liquids. Both backbone H1-C13 and side-chain resonances were enhanced, enabling secondary and tertiary structure analysis of proteins with remarkable spectral editing, via the 13C PREPRINT pulse sequence. Laser-enhanced 2D NMR spectra of 5 μM proteins at 600 MHz display 30-fold better S/N than conventional 2D data collected at 900 MHz. Sensitivity enhancements achieved with this technology, denoted as low-concentration photo-CIDNP (LC-photo-CIDNP), depend only weakly on laser intensity, highlighting the opportunity of safer and more cost-effective hypersensitive NMR applications employing low-power laser sources.
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Kouřil K, Kouřilová H, Bartram S, Levitt MH, Meier B. Scalable dissolution-dynamic nuclear polarization with rapid transfer of a polarized solid. Nat Commun 2019; 10:1733. [PMID: 30988293 PMCID: PMC6465283 DOI: 10.1038/s41467-019-09726-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 03/27/2019] [Indexed: 12/02/2022] Open
Abstract
In dissolution-dynamic nuclear polarization, nuclear spins are hyperpolarized at cryogenic temperatures using radicals and microwave irradiation. The hyperpolarized solid is dissolved with hot solvent and the solution is transferred to a secondary magnet where strongly enhanced magnetic resonance signals are observed. Here we present a method for transferring the hyperpolarized solid. A bullet containing the frozen, hyperpolarized sample is ejected using pressurized helium gas, and shot into a receiving structure in the secondary magnet, where the bullet is retained and the polarized solid is dissolved rapidly. The transfer takes approximately 70 ms. A solenoid, wound along the entire transfer path ensures adiabatic transfer and limits radical-induced low-field relaxation. The method is fast and scalable towards small volumes suitable for high-resolution nuclear magnetic resonance spectroscopy while maintaining high concentrations of the target molecule. Polarization levels of approximately 30% have been observed for 1-13C-labelled pyruvic acid in solution.
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Affiliation(s)
- Karel Kouřil
- School of Chemistry, University of Southampton, Southampton, SO17 1BJ, United Kingdom.
| | - Hana Kouřilová
- School of Chemistry, University of Southampton, Southampton, SO17 1BJ, United Kingdom
| | - Samuel Bartram
- School of Chemistry, University of Southampton, Southampton, SO17 1BJ, United Kingdom
| | - Malcolm H Levitt
- School of Chemistry, University of Southampton, Southampton, SO17 1BJ, United Kingdom
| | - Benno Meier
- School of Chemistry, University of Southampton, Southampton, SO17 1BJ, United Kingdom.
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29
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Kadeřávek P, Ferrage F, Bodenhausen G, Kurzbach D. High-Resolution NMR of Folded Proteins in Hyperpolarized Physiological Solvents. Chemistry 2018; 24:13418-13423. [PMID: 29969165 DOI: 10.1002/chem.201802885] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 06/28/2018] [Indexed: 11/10/2022]
Abstract
Hyperpolarized 2D exchange spectroscopy (HYPEX) to obtain high-resolution nuclear magnetic resonance (NMR) spectra of folded proteins under near-physiological conditions is reported. The technique is based on hyperpolarized water, which is prepared by dissolution dynamic nuclear polarization and mixed in situ in an NMR spectrometer with a protein in a physiological saline buffer at body temperature. Rapid exchange of labile protons with the hyperpolarized solvent, combined with cross-relaxation effects (NOEs), leads to boosted signal intensities for many amide 1 H-15 N correlations in the protein ubiquitin. As the introduction of hyperpolarization to the target protein is mediated via the solvent, the method is applicable to a broad spectrum of target molecules.
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Affiliation(s)
- Pavel Kadeřávek
- CEITEC-Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
| | - Fabien Ferrage
- Laboratoire des biomolécules, LBM, Département de chimie, École normale supérieure, PSL University, Sorbonne Université, CNRS, 75005, Paris, France
| | - Geoffrey Bodenhausen
- Laboratoire des biomolécules, LBM, Département de chimie, École normale supérieure, PSL University, Sorbonne Université, CNRS, 75005, Paris, France
| | - Dennis Kurzbach
- Laboratoire des biomolécules, LBM, Département de chimie, École normale supérieure, PSL University, Sorbonne Université, CNRS, 75005, Paris, France
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