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Meikle TG, Keizer DW, Separovic F, Yao S. Insights into dynamic properties of water in lipidic cubic phases by 2D nuclear Overhauser effect (NOE) NMR spectroscopy. J Colloid Interface Sci 2024; 666:659-669. [PMID: 38616448 DOI: 10.1016/j.jcis.2024.04.054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 04/03/2024] [Accepted: 04/08/2024] [Indexed: 04/16/2024]
Abstract
Two-dimensional NOE (nuclear Overhauser effect) NMR spectroscopy was employed to investigate the dynamic properties of water within lyotropic bicontinuous lipidic cubic phases (LCPs) formed by monoolein (MO). Experiments observed categorically different effective residence times of water molecules: (i) in proximity to the glycerol moiety of MO, and (ii) adjacent to the hydrophobic chain towards the hydrocarbon tail of MO, as evidenced by the opposite signs of intermolecular NOE cross peaks between protons of water and those of MO in 2D 1H-1H NOESY spectra. Spectroscopic data delineating the different effective residence times of water molecules within both the gyroid (QIIG) and diamond (QIID) phase groups corresponding to hydration levels of 35 and 40 wt%, respectively, are presented. Additionally, an increase in effective residence time of water molecules in proximity to the glycerol moiety of MO in LCPs was observed upon storage at ambient temperature and in the presence of an additive lipid, cholesterol. Atom-specific NOE build-up curves for protons of water and those of MO are also given. The results presented herein provide new insight into the physicochemical properties and behaviour of water in LCPs, and demonstrate an additional avenue for experimental study of water-lipid interactions and hydration dynamics in model membranes and nanomaterials using 2D NOE NMR spectroscopy.
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Affiliation(s)
- Thomas G Meikle
- Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia
| | - David W Keizer
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, VIC 3010, Australia
| | - Frances Separovic
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, VIC 3010, Australia; School of Chemistry, The University of Melbourne, VIC 3010, Australia
| | - Shenggen Yao
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, VIC 3010, Australia.
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2
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Mignon C, Ortiz Moreno AR, Shirzad H, Padamati SK, Damle VG, Ong Y, Schirhagl R, Chipaux M. Fast, Broad-Band Magnetic Resonance Spectroscopy with Diamond Widefield Relaxometry. ACS Sens 2023; 8:1667-1675. [PMID: 37043367 PMCID: PMC10152489 DOI: 10.1021/acssensors.2c02809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
We present an alternative to conventional Electron Paramagnetic Resonance (EPR) spectroscopy equipment. Avoiding the use of bulky magnets and magnetron equipment, we use the photoluminescence of an ensemble of Nitrogen-Vacancy centers at the surface of a diamond. Monitoring their relaxation time (or T1), we detected their cross-relaxation with a compound of interest. In addition, the EPR spectra are encoded through a localized magnetic field gradient. While recording previous data took 12 min per data point with individual NV centers, we were able to reconstruct a full spectrum at once in 3 s, over a range from 3 to 11 G. In terms of sensitivity, only 0.5 μL of a 1 μM hexaaquacopper(II) ion solution was necessary.
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Affiliation(s)
- Charles Mignon
- Groningen University, University Medical Center Groningen, Antonius Deusinglaan 1, 9713 AW Groningen, The Netherlands
| | - Ari R Ortiz Moreno
- Groningen University, University Medical Center Groningen, Antonius Deusinglaan 1, 9713 AW Groningen, The Netherlands
| | - Hoda Shirzad
- Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Sandeep K Padamati
- Groningen University, University Medical Center Groningen, Antonius Deusinglaan 1, 9713 AW Groningen, The Netherlands
| | - Viraj G Damle
- Groningen University, University Medical Center Groningen, Antonius Deusinglaan 1, 9713 AW Groningen, The Netherlands
| | - Yori Ong
- Groningen University, University Medical Center Groningen, Antonius Deusinglaan 1, 9713 AW Groningen, The Netherlands
| | - Romana Schirhagl
- Groningen University, University Medical Center Groningen, Antonius Deusinglaan 1, 9713 AW Groningen, The Netherlands
| | - Mayeul Chipaux
- Groningen University, University Medical Center Groningen, Antonius Deusinglaan 1, 9713 AW Groningen, The Netherlands
- Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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3
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Abstract
Different NMR methodologies have been considered in studying water as a part of the structure of heterogeneous biosystems. The current work mostly describes NMR techniques to investigate slow translational dynamics of molecules affecting anisotropic properties of polymers and biomaterials. With these approaches, information about organized structures and their stability could be obtained in conditions when external factors affect biomolecules. Such changes might include rearrangement of macromolecular conformations at fabrication of nano-scaffolds for tissue engineering applications. The changes in water-fiber interactions could be mirrored by the magnetic resonance methods in various relaxations, double-quantum filtered (DQF), 1D and 2D translational diffusion experiments. These findings effectively demonstrate the current state of NMR studies in applying these experiments to the various systems with the anisotropic properties. For fibrous materials, it is shown how NMR correlation experiments with two gradients (orthogonal or collinear) encode diffusion coefficients in anisotropic materials and how to estimate the permeability of cell walls. It is considered how the DQF NMR technique discovers anisotropic water in natural polymers with various cross-links. The findings clarify hydration sites, dynamic properties, and binding of macromolecules discovering the role of specific states in improving scaffold characteristics in tissue engineering processes. Showing the results in developing these NMR tools, this review focuses on the ways of extracting information about biophysical properties of biomaterials from the NMR data obtained.
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Affiliation(s)
- Victor V Rodin
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstraße 69, 4040, Linz, Austria.
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4
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Park H, Uluca-Yazgi B, Heumann S, Schlögl R, Granwehr J, Heise H, Schleker PPM. Heteronuclear cross-relaxation effect modulated by the dynamics of N-functional groups in the solid state under 15N DP-MAS DNP. J Magn Reson 2020; 312:106688. [PMID: 32004819 DOI: 10.1016/j.jmr.2020.106688] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 01/12/2020] [Accepted: 01/14/2020] [Indexed: 06/10/2023]
Abstract
In a typical magic-angle spinning (MAS) dynamic nuclear polarization (DNP) nuclear magnetic resonance (NMR) experiment, several mechanisms are simultaneously involved when transferring much larger polarization of electron spins to NMR active nuclei of interest. Recently, specific cross-relaxation enhancement by active motions under DNP (SCREAM-DNP) [Daube et al. JACS 2016] has been reported as one of these mechanisms. Thereby 13C enhancement with inverted sign was observed in a direct polarization (DP) MAS DNP experiment, caused by reorientation dynamics of methyl that was not frozen out at 100 K. Here, we report on the spontaneous polarization transfer from hyperpolarized 1H to both primary amine and ammonium nitrogens, resulting in an additional positive signal enhancement in the 15N NMR spectra during 15N DP-MAS DNP. The cross-relaxation induced signal enhancement (CRE) for 15N is of opposite sign compared to that observed for 13C due to the negative sign of the gyromagnetic ratio of 15N. The influence on CRE efficiency caused by variation of the radical solution composition and by temperature was also investigated.
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Affiliation(s)
- Heeyong Park
- Max Planck Institute for Chemical Energy Conversion, Department of Heterogeneous Reactions, 45470 Mülheim an der Ruhr, Germany; Forschungszentrum Jülich, IEK-9, 52425 Jülich, Germany; RWTH Aachen University, Institute of Technical and Macromolecular Chemistry, 52074 Aachen, Germany
| | - Boran Uluca-Yazgi
- Forschungszentrum Jülich, IBI-7 and JuStruct, 52425 Jülich, Germany; Heinrich Heine Universität Düsseldorf, Institute of Physical Biology, 40225 Düsseldorf, Germany
| | - Saskia Heumann
- Max Planck Institute for Chemical Energy Conversion, Department of Heterogeneous Reactions, 45470 Mülheim an der Ruhr, Germany
| | - Robert Schlögl
- Max Planck Institute for Chemical Energy Conversion, Department of Heterogeneous Reactions, 45470 Mülheim an der Ruhr, Germany; Fritz Haber Institute of the Max Planck Society, 14195 Berlin, Germany
| | - Josef Granwehr
- Forschungszentrum Jülich, IEK-9, 52425 Jülich, Germany; RWTH Aachen University, Institute of Technical and Macromolecular Chemistry, 52074 Aachen, Germany
| | - Henrike Heise
- Forschungszentrum Jülich, IBI-7 and JuStruct, 52425 Jülich, Germany; Heinrich Heine Universität Düsseldorf, Institute of Physical Biology, 40225 Düsseldorf, Germany
| | - P Philipp M Schleker
- Max Planck Institute for Chemical Energy Conversion, Department of Heterogeneous Reactions, 45470 Mülheim an der Ruhr, Germany; Forschungszentrum Jülich, IEK-9, 52425 Jülich, Germany.
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5
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Abstract
We outline the physical properties of hydration water that are captured by Overhauser Dynamic Nuclear Polarization (ODNP) relaxometry and explore the insights that ODNP yields about the water and the surface that this water is coupled to. As ODNP relies on the pairwise cross-relaxation between the electron spin of a spin probe and a proton nuclear spin of water, it captures the dynamics of single-particle diffusion of an ensemble of water molecules moving near the spin probe. ODNP principally utilizes the same physics as other nuclear magnetic resonance (NMR) relaxometry (i.e., relaxation measurement) techniques. However, in ODNP, electron paramagnetic resonance (EPR) excites the electron spins probes and their high net polarization acts as a signal amplifier. Furthermore, it renders ODNP parameters highly sensitive to water moving at rates commensurate with the EPR frequency of the spin probe (typically 10GHz). Also, ODNP selectively enhances the NMR signal contributions of water moving within close proximity to the spin label. As a result, ODNP can capture ps-ns movements of hydration waters with high sensitivity and locality, even in samples with protein concentrations as dilute as 10 µM. To date, the utility of the ODNP technique has been demonstrated for two major applications: the characterization of the spatial variation in the properties of the hydration layer of proteins or other surfaces displaying topological diversity, and the identification of structural properties emerging from highly disordered proteins and protein domains. The former has been shown to correlate well with the properties of hydration water predicted by MD simulations and has been shown capable of evaluating the hydrophilicity or hydrophobicity of a surface. The latter has been demonstrated for studies of an interhelical loop of proteorhodopsin, the partial structure of α-synuclein embedded at the lipid membrane surface, incipient structures adopted by tau proteins en route to fibrils, and the structure and hydration profile of a transmembrane peptide. This chapter focuses on offering a mechanistic understanding of the ODNP measurement and the molecular dynamics encoded in the ODNP parameters. In particular, it clarifies how the electron-nuclear dipolar coupling encodes information about the molecular dynamics in the nuclear spin self-relaxation and, more importantly, the electron-nuclear spin cross-relaxation rates. The clarification of the molecular dynamics underlying ODNP should assist in establishing a connection to theory and computer simulation that will offer far richer interpretations of ODNP results in future studies.
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Affiliation(s)
- John M Franck
- Department of Chemistry, Syracuse University, Syracuse, NY, United States.
| | - Songi Han
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, CA, United States; Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, CA, United States
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Alonso-Valdesueiro J, Elliott SJ, Bengs C, Meier B, Levitt MH. Testing signal enhancement mechanisms in the dissolution NMR of acetone. J Magn Reson 2018; 286:158-162. [PMID: 29253726 DOI: 10.1016/j.jmr.2017.12.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Revised: 12/11/2017] [Accepted: 12/12/2017] [Indexed: 06/07/2023]
Abstract
In cryogenic dissolution NMR experiments, a substance of interest is allowed to rest in a strong magnetic field at cryogenic temperature, before dissolving the substance in a warm solvent, transferring it to a high-resolution NMR spectrometer, and observing the solution-state NMR spectrum. In some cases, negative enhancements of the 13C NMR signals are observed, which have been attributed to quantum-rotor-induced polarization. We show that in the case of acetone (propan-2-one) the negative signal enhancements of the methyl 13C sites may be understood by invoking conventional cross-relaxation within the methyl groups. The 1H nuclei acquire a relative large net polarization through thermal equilibration in a magnetic field at low temperature, facilitated by the methyl rotation which acts as a relaxation sink; after dissolution, the 1H magnetization slowly returns to thermal equilibrium at high temperature, in part by cross-relaxation processes, which induce a transient negative polarization of nearby 13C nuclei. We provide evidence for this mechanism experimentally and theoretically by saturating the 1H magnetization using a radiofrequency field pulse sequence before dissolution and comparing the 13C magnetization evolution after dissolution with the results obtained from a conventional 1H-13C cross relaxation model of the CH3 moieties in acetone.
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Affiliation(s)
| | - Stuart J Elliott
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Christian Bengs
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Benno Meier
- 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.
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Woźniak-Braszak A. Study of cross - relaxation and molecular dynamics in the solid 3-(trifluoromethyl) benzoic acid by solid state NMR off - resonance. Solid State Nucl Magn Reson 2017; 81:8-10. [PMID: 27960099 DOI: 10.1016/j.ssnmr.2016.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 11/30/2016] [Accepted: 12/04/2016] [Indexed: 06/06/2023]
Abstract
Molecular dynamics of the solid 3-(trifluoromethyl) benzoic acid containing proton 1H and fluorine 19F nuclei was explored by the solid-state NMR off - resonance technique. Contrary to the previous experiments the proton nuclei system I relaxed in the off - resonance effective field B→e while fluorine nuclei system S was saturated for short time in comparison to the relaxation time T1I. New cross - relaxation solid - state NMR off - resonance experiments were conducted on a homebuilt pulse spectrometer operating at the on-resonance frequency of 30.2MHz, at the off - resonance frequency varied between 30.2 and 30.6MHz for protons and at the frequency of 28.411MHz for fluorines, respectively. Based on the experimental data the dispersions of the proton off - resonance spin - lattice relaxation rate ρρI, the fluorine off - resonance spin - lattice relaxation rate ρρS and the cross - relaxation rate σρ in the rotating frame were determined.
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Affiliation(s)
- Aneta Woźniak-Braszak
- High Pressure Physics Division, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznan, Poland.
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8
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Gregorovič A, Apih T, Seliger J. (1)H-(14)N cross-relaxation spectrum analysis in sildenafil and sildenafil citrate. Solid State Nucl Magn Reson 2016; 78:16-23. [PMID: 27379753 DOI: 10.1016/j.ssnmr.2016.05.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 03/24/2016] [Accepted: 05/19/2016] [Indexed: 06/06/2023]
Abstract
Here we describe a method for the extraction of (14)N quadrupole parameters from a (1)H-(14)N cross-relaxation spectrum by fitting the lineshapes of the (14)N quadrupole transitions. The procedures used typically to fit quadrupole lineshapes are not directly applicable to fit the (1)H-(14)N cross-relaxation spectrum, because the presence of proton homonuclear dipolar interaction broadens the lineshapes considerably and prevents a reliable determination of Cq and η from a single lineshape. Instead, one must fit two or even three lineshapes originating from the same nitrogen site simultaneously. The problem is to identify which lineshapes belong together when many are observed due to the existence of several nitrogen sites. We solve this problem by fitting the spectrum for all possible combinations and find the best-fitting one. This combination then most likely correctly identifies lineshapes belonging to the same nitrogen site. There are two main advantages of our method compared to the typically used method, which relies only on lineshape singularities: (i) the method is "automatic" and does not require knowledge of nitrogen quadrupole parameters in similar environments to aid dip pairing and (ii) the accuracy of quadrupole parameters is better, as proton linewidth is included in the fits. We use sildenafil and sildenafil citrate as model compounds, each with six non-equivalent nitrogen sites.
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Affiliation(s)
- Alan Gregorovič
- Institute "Jožef Stefan", Jamova 39, 1000 Ljubljana, Slovenia.
| | - Tomaž Apih
- Institute "Jožef Stefan", Jamova 39, 1000 Ljubljana, Slovenia
| | - Janez Seliger
- Institute "Jožef Stefan", Jamova 39, 1000 Ljubljana, Slovenia; Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000 Ljubljana, Slovenia
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9
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Baranowski M, Woźniak-Braszak A, Jurga K. Adiabatic fast passage application in solid state NMR study of cross relaxation and molecular dynamics in heteronuclear systems. J Magn Reson 2016; 262:27-32. [PMID: 26705906 DOI: 10.1016/j.jmr.2015.11.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 11/12/2015] [Accepted: 11/21/2015] [Indexed: 06/05/2023]
Abstract
The paper presents the benefits of using fast adiabatic passage for the study of molecular dynamics in the solid state heteronuclear systems in the laboratory frame. A homemade pulse spectrometer operating at the frequency of 30.2MHz and 28.411MHz for protons and fluorines, respectively, has been enhanced with microcontroller direct digital synthesizer DDS controller [1-4]. This work briefly describes how to construct a low-cost and easy-to-assemble adiabatic extension set for homemade and commercial spectrometers based on recently very popular Arduino shields. The described set was designed for fast adiabatic generation. Timing and synchronization problems are discussed. The cross-relaxation experiments with different initial states of the two spin systems have been performed. Contrary to our previous work [5] where the steady-state NOE experiments were conducted now proton spins (1)H are polarized in the magnetic field B0 while fluorine spins (19)F are perturbed by selective saturation for a short time and then the system is allowed to evolve for a period in the absence of a saturating field. The adiabatic passage application leads to a reversal of magnetization of fluorine spins and increases the amplitude of the signal.
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Affiliation(s)
- M Baranowski
- High Pressure Physics Division, Department of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznan, Poland.
| | - A Woźniak-Braszak
- High Pressure Physics Division, Department of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznan, Poland
| | - K Jurga
- High Pressure Physics Division, Department of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznan, Poland
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Jurga K, Woźniak-Braszak A, Baranowski M. Methodology for solid state NMR off-resonance study of molecular dynamics in heteronuclear systems. Solid State Nucl Magn Reson 2015; 71:73-79. [PMID: 26272112 DOI: 10.1016/j.ssnmr.2015.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 05/11/2015] [Accepted: 08/03/2015] [Indexed: 06/04/2023]
Abstract
Methodology for the study of dynamics in heteronuclear systems in the laboratory frame was described in the previous paper [1]. Now the methodology for the study of molecular dynamics in the solid state heteronuclear systems in the rotating frame is presented. The solid state NMR off-resonance experiments were carried out on a homemade pulse spectrometer operating at the frequency of 30.2 MHz for protons. This spectrometer includes a specially designed probe which contains two independently tuned and electrically isolated coils installed in the coaxial position on the dewar. A unique probe design allows working at three slightly differing frequencies off and on resonance for protons and at the frequency of 28.411 MHz for fluorine nuclei with complete absence of their electrical interference. The probe allows simultaneously creating rf magnetic fields at off-resonance frequencies within the range of 30.2-30.6 MHz and at the frequency of 28.411 MHz. Presented heteronuclear cross-relaxation off-resonance experiments in the rotating frame provide information about molecular dynamics.
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Affiliation(s)
- Kazimierz Jurga
- High Pressure Physics Division, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznan, Poland
| | - Aneta Woźniak-Braszak
- High Pressure Physics Division, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznan, Poland.
| | - Mikołaj Baranowski
- High Pressure Physics Division, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznan, Poland
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Pagès G, Dvinskikh SV, Furó I. Suppressing magnetization exchange effects in stimulated-echo diffusion experiments. J Magn Reson 2013; 234:35-43. [PMID: 23838524 DOI: 10.1016/j.jmr.2013.06.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 05/29/2013] [Accepted: 06/02/2013] [Indexed: 06/02/2023]
Abstract
Exchange of nuclear magnetization between spin pools, either by chemical exchange or by cross-relaxation or both, has a significant influence on the signal attenuation in stimulated-echo-type pulsed field gradient experiments. Hence, in such cases the obtained molecular self-diffusion coefficients can carry a large systematic error. We propose a modified stimulated echo pulse sequence that contains T2-filters during the z-magnetization store period. We demonstrate, using a common theoretical description for chemical exchange and cross-relaxation, that these filters suppress the effects of exchange on the diffusional decay in that frequent case where one of the participating spin pools is immobile and exhibits a short T2. We demonstrate the performance of this experiment in an agarose/water gel. We posit that this new experiment has advantages over other approaches hitherto used, such as that consisting of measuring separately the magnetization exchange rate, if suitable by Goldman-Shen type experiments, and then correcting for exchange effects within the framework of a two-site exchange model. We also propose experiments based on selective decoupling and applicable in systems with no large T2 difference between the different spin pools.
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Affiliation(s)
- Guilhem Pagès
- Division of Applied Physical Chemistry, Department of Chemistry, KTH Royal Institute of Technology, 100 44 Stockholm, Sweden.
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