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Hayashi S, Jimura K. Spin diffusion and 1H spin-lattice relaxation in Cs 2(HSO 4)(H 2PO 4) containing a small amount of ammonium ions. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2017; 88:15-21. [PMID: 29126075 DOI: 10.1016/j.ssnmr.2017.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 10/23/2017] [Accepted: 10/24/2017] [Indexed: 06/07/2023]
Abstract
Inorganic solid acid salts with hydrogen bond networks frequently show very long spin-lattice relaxation times even for 1H because the hydrogen bonds suppress motions. In the present work, the 1H spin-lattice relaxation in Cs2(HSO4)(H2PO4) containing a small amount of ammonium ions were studied in detail by use of the effect of magic angle spinning (MAS) on the relaxation. The 1H spin-lattice relaxation times of the acid protons decrease with increase in the content of ammonium ions. Reorientation of the NH4 group fluctuates the dipole-dipole interaction and relaxes the ammonium protons as well as the acid protons. The 1H relaxation times of the acid protons are a little bit longer than those of the ammonium protons at the MAS rate of 8 kHz. The spinning at 50 kHz makes the relaxation times of the acid protons longer and those of the ammonium protons shorter. Spin diffusion between the acid and the ammonium protons averages partially the 1H relaxation of the acid and the ammonium protons at the MAS rate of 8 kHz. The spin diffusion is suppressed completely at the MAS rate of 50 kHz. Spin diffusion between the acid protons is not suppressed at the MAS rate of 50 kHz. The acid protons always show the same relaxation times. The intrinsic relaxation times not affected by spin diffusion are evaluated quantitatively for both the acid and the ammonium protons. Those values are independent of the ammonium content. Contribution of the spin diffusion between the acid and the ammonium protons to the relaxation is estimated quantitatively. Using those parameters, the effect of ammonium ions on the 1H spin-lattice relaxation can be predicted. The 1H spin-lattice relaxation is a sensitive tool to study the distribution of ammonium ions in solids.
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Affiliation(s)
- Shigenobu Hayashi
- Research Institute for Material and Chemical Measurement, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan.
| | - Keiko Jimura
- Research Institute for Material and Chemical Measurement, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
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Hayashi S, Jimura K. Detailed mechanisms of 1H spin-lattice relaxation in ammonium dihydrogen phosphate confirmed by magic angle spinning. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2017; 87:24-28. [PMID: 28728051 DOI: 10.1016/j.ssnmr.2017.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 07/04/2017] [Accepted: 07/05/2017] [Indexed: 06/07/2023]
Abstract
Mechanisms of the 1H spin-lattice relaxation in NH4H2PO4 were studied in detail by use of the effect of magic angle spinning on the relaxation. The acid and the ammonium protons have different relaxation times at the spinning rates higher than 10 kHz due to suppression of spin diffusion between the two kinds of protons. The intrinsic relaxation times not affected by the spin diffusion and the spin-diffusion assisted relaxation times were evaluated separately, taking into consideration temperature dependence. Both mechanisms contribute to the 1H relaxation of the acid protons comparatively. The spin-diffusion assisted relaxation mechanism was suppressed to the level lower than the experimental errors at the spinning rate of 30 kHz.
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Affiliation(s)
- Shigenobu Hayashi
- Research Institute for Material and Chemical Measurement, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8565, Japan.
| | - Keiko Jimura
- Research Institute for Material and Chemical Measurement, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8565, Japan
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Shmyreva AA, Safdari M, Furó I, Dvinskikh SV. NMR longitudinal relaxation enhancement in metal halides by heteronuclear polarization exchange during magic-angle spinning. J Chem Phys 2016; 144:224201. [DOI: 10.1063/1.4953540] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Abraham A, Apperley DC, Byard SJ, Ilott AJ, Robbins AJ, Zorin V, Harris RK, Hodgkinson P. Characterising the role of water in sildenafil citrate by NMR crystallography. CrystEngComm 2016. [DOI: 10.1039/c5ce02234g] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A combination of solid-state NMR techniques, including 13C/1H correlation, 2H magic-angle spinning NMR and first principles calculation are employed to characterise the role of water in different hydration states of sildenafil citrate.
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Affiliation(s)
- Anuji Abraham
- Department of Chemistry
- University of Durham
- Durham DH1 3LE, UK
| | | | | | - Andrew J. Ilott
- Department of Chemistry
- University of Durham
- Durham DH1 3LE, UK
| | | | - Vadim Zorin
- Department of Chemistry
- University of Durham
- Durham DH1 3LE, UK
| | - Robin K. Harris
- Department of Chemistry
- University of Durham
- Durham DH1 3LE, UK
| | - Paul Hodgkinson
- Department of Chemistry
- University of Durham
- Durham DH1 3LE, UK
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Chen Z, Cai S, Huang Y, Lin Y. High-resolution NMR spectroscopy in inhomogeneous fields. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2015; 90-91:1-31. [PMID: 26592943 DOI: 10.1016/j.pnmrs.2015.05.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 05/20/2015] [Accepted: 05/20/2015] [Indexed: 06/05/2023]
Abstract
High-resolution NMR spectroscopy, providing information on chemical shifts, J coupling constants, multiplet patterns, and relative peak areas, is a mainstream tool for analysis of molecular structures, conformations, compositions, and dynamics. Generally, a homogeneous magnetic field is a prerequisite for obtaining high-resolution NMR information. Magnetic field inhomogeneity, whether from non-ideal experimental conditions or from intrinsic magnetic susceptibility discontinuities in samples, represents a hurdle for applications of high-resolution NMR. Numerous techniques have been proposed for measuring high-resolution NMR spectra free from the influence of inhomogeneous magnetic fields. Besides developments and improvements in NMR instrumentation, various types of experimental approaches have been established for recovering NMR information in inhomogeneous magnetic fields. Three main types are systematically described in this review. In addition, other high-resolution NMR approaches or data processing methods are also briefly described. All high-resolution NMR approaches covered in this review have individual advantages and disadvantages in practical applications, and no one technique is applicable to all practical circumstances. Hence, they are complementary for high-resolution NMR applications in inhomogeneous fields. The underlying mechanisms of these approaches are presented, together with analyses of their applicability and efficiency.
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Affiliation(s)
- Zhong Chen
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, Fujian 361005, China.
| | - Shuhui Cai
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, Fujian 361005, China
| | - Yuqing Huang
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, Fujian 361005, China
| | - Yulan Lin
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, Fujian 361005, China
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Robertson AJ, Pandey MK, Marsh A, Nishiyama Y, Brown SP. The use of a selective saturation pulse to suppress t1 noise in two-dimensional (1)H fast magic angle spinning solid-state NMR spectroscopy. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2015; 260:89-97. [PMID: 26432398 DOI: 10.1016/j.jmr.2015.09.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 09/01/2015] [Accepted: 09/07/2015] [Indexed: 06/05/2023]
Abstract
A selective saturation pulse at fast magic angle spinning (MAS) frequencies (60+kHz) suppresses t1 noise in the indirect dimension of two-dimensional (1)H MAS NMR spectra. The method is applied to a synthetic nucleoside with an intense methyl (1)H signal due to triisopropylsilyl (TIPS) protecting groups. Enhanced performance in terms of suppressing the methyl signal while minimising the loss of signal intensity of nearby resonances of interest relies on reducing spin diffusion--this is quantified by comparing two-dimensional (1)H NOESY-like spin diffusion spectra recorded at 30-70 kHz MAS. For a saturation pulse centred at the methyl resonance, the effect of changing the nutation frequency at different MAS frequencies as well as the effect of changing the pulse duration is investigated. By applying a pulse of duration 30 ms and nutation frequency 725 Hz at 70 kHz MAS, a good compromise of significant suppression of the methyl resonance combined with the signal intensity of resonances greater than 5 ppm away from the methyl resonance being largely unaffected is achieved. The effectiveness of using a selective saturation pulse is demonstrated for both homonuclear (1)H-(1)H double quantum (DQ)/single quantum (SQ) MAS and (14)N-(1)H heteronuclear multiple quantum coherence (HMQC) two-dimensional solid-state NMR experiments.
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Affiliation(s)
- Aiden J Robertson
- Department of Physics, University of Warwick, Coventry CV4 7AL, United Kingdom; Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Manoj Kumar Pandey
- RIKEN CLST-JEOL Collaboration Centre, Yokohama, Kanagawa 230-0045, Japan
| | - Andrew Marsh
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Yusuke Nishiyama
- RIKEN CLST-JEOL Collaboration Centre, Yokohama, Kanagawa 230-0045, Japan; JEOL RESONANCE Inc., Musashino, Akishima, Tokyo 196-8558, Japan
| | - Steven P Brown
- Department of Physics, University of Warwick, Coventry CV4 7AL, United Kingdom.
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Chan-Huot M, Wimperis S, Gervais C, Bodenhausen G, Duma L. Deuterium MAS NMR Studies of Dynamics on Multiple Timescales: Histidine and Oxalic Acid. Chemphyschem 2014; 16:204-15. [DOI: 10.1002/cphc.201402506] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Indexed: 11/11/2022]
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Vugmeyster L, Ostrovsky D, Ford JJ, Lipton AS. Freezing of dynamics of a methyl group in a protein hydrophobic core at cryogenic temperatures by deuteron NMR spectroscopy. J Am Chem Soc 2010; 132:4038-9. [PMID: 20201523 DOI: 10.1021/ja909599k] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Methyl groups are thought to dominate the dynamics of proteins after slow collective modes of motion freeze out in a glass-transition process. In this work we investigate methyl group dynamics of a key hydrophobic core leucine residue in chicken villin headpiece subdomain protein at 140-4 K using deuteron NMR longitudinal relaxation measurements. A distinct increase in the apparent activation energy is observed at approximately 95 K, indicating an abrupt freezing of methyl group dynamics. Relaxation times at temperatures below 60 K are dominated by the deuteron tunneling mechanism.
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Vugmeyster L, Ostrovsky D, Ford JJ, Burton SD, Lipton AS, Hoatson GL, Vold RL. Probing the dynamics of a protein hydrophobic core by deuteron solid-state nuclear magnetic resonance spectroscopy. J Am Chem Soc 2009; 131:13651-8. [PMID: 19772361 DOI: 10.1021/ja902977u] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
With the goal of investigating dynamical features of hydrophobic cores of proteins over a wide range of temperatures, the chicken villin headpiece subdomain protein (HP36) was labeled at a "single" site corresponding to any one of the two C(delta)D(3) groups of leucine-69, which is located in a key position of the core. The main techniques employed are deuteron NMR quadrupolar echo line shape analysis, and T(1Z) (Zeeman) and T(1Q) (quadrupolar order) relaxation experiments performed at 11.7 and 17.6 T over the temperature range of 112 to 298 K. The experimental data are compared with computer simulations. The deuteron line shapes give an excellent fit to a three-mode motional model that consists of (a) fast three-site rotational jumps about the pseudo C(3) methyl spinning axis, (b) slower reorientation of the spinning axis, described by diffusion along a restricted arc, and (c) large angle jumps between traces of rotameric conformers. Relaxation behavior is described by a phenomenological distribution of activation energies for three-site hops at high temperatures that collapses to a single, distinctly smaller value for lower temperatures.
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