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Abstract
In the last two decades, solid-state nuclear magnetic resonance (ssNMR) spectroscopy has transformed from a spectroscopic technique investigating small molecules and industrial polymers to a potent tool decrypting structure and underlying dynamics of complex biological systems, such as membrane proteins, fibrils, and assemblies, in near-physiological environments and temperatures. This transformation can be ascribed to improvements in hardware design, sample preparation, pulsed methods, isotope labeling strategies, resolution, and sensitivity. The fundamental engagement between nuclear spins and radio-frequency pulses in the presence of a strong static magnetic field is identical between solution and ssNMR, but the experimental procedures vastly differ because of the absence of molecular tumbling in solids. This review discusses routinely employed state-of-the-art static and MAS pulsed NMR methods relevant for biological samples with rotational correlation times exceeding 100's of nanoseconds. Recent developments in signal filtering approaches, proton methodologies, and multiple acquisition techniques to boost sensitivity and speed up data acquisition at fast MAS are also discussed. Several examples of protein structures (globular, membrane, fibrils, and assemblies) solved with ssNMR spectroscopy have been considered. We also discuss integrated approaches to structurally characterize challenging biological systems and some newly emanating subdisciplines in ssNMR spectroscopy.
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Affiliation(s)
- Sahil Ahlawat
- Tata Institute of Fundamental Research Hyderabad, Survey No. 36/P Gopanpally, Serilingampally, Ranga Reddy District, Hyderabad 500046, Telangana, India
| | - Kaustubh R Mote
- Tata Institute of Fundamental Research Hyderabad, Survey No. 36/P Gopanpally, Serilingampally, Ranga Reddy District, Hyderabad 500046, Telangana, India
| | - Nils-Alexander Lakomek
- University of Düsseldorf, Institute for Physical Biology, Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Vipin Agarwal
- Tata Institute of Fundamental Research Hyderabad, Survey No. 36/P Gopanpally, Serilingampally, Ranga Reddy District, Hyderabad 500046, Telangana, India
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2
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Concistré M, Paul S, Carravetta M, Kuprov I, Williamson PTF. Strategies for 1 H-Detected Dynamic Nuclear Polarization Magic-Angle Spinning NMR Spectroscopy. Chemistry 2020; 26:15852-15854. [PMID: 32827182 PMCID: PMC7756879 DOI: 10.1002/chem.202003463] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Indexed: 11/09/2022]
Abstract
Combining dynamic nuclear polarization with proton detection significantly enhances the sensitivity of magic-angle spinning NMR spectroscopy. Herein, the feasibility of proton-detected experiments with slow (10 kHz) magic angle spinning was demonstrated. The improvement in sensitivity permits the acquisition of indirectly detected 14 N NMR spectra allowing biomolecular structures to be characterized without recourse to isotope labelling. This provides a new tool for the structural characterization of environmental and medical samples, in which isotope labelling is frequently intractable.
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Affiliation(s)
- Maria Concistré
- School of ChemistryUniversity of SouthamptonSouthamptonSO171BJUK
| | - Subhradip Paul
- Sir Peter Mansfield Imaging CentreUniversity of NottinghamNottinghamUK
| | | | - Ilya Kuprov
- School of ChemistryUniversity of SouthamptonSouthamptonSO171BJUK
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3
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Paruzzo FM, Emsley L. High-resolution 1H NMR of powdered solids by homonuclear dipolar decoupling. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2019; 309:106598. [PMID: 31586820 DOI: 10.1016/j.jmr.2019.106598] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 09/13/2019] [Accepted: 09/13/2019] [Indexed: 06/10/2023]
Abstract
The development of homonuclear dipolar decoupling sequences to obtain high-resolution 1H NMR spectra from solids has recently celebrated its 50th birthday. Over the years, a series of different decoupling schemes have been developed, starting with the pioneering Lee-Goldburg and WAHUHA sequences up to the most recent generation of experimentally optimized phase-modulated schemes such as eDUMBO-122 and LG4. These schemes can all yield over an order of magnitude reduction in 1H NMR linewidths in solids. Here we provide an overview and a broad experimental comparison of the performance of the main sequences, which has so far been absent in the literature, especially between the newest and the oldest decoupling schemes. We compare experimental results obtained using eight different decoupling schemes (LG, WHH-4, MREV-8, BR-24, FSLG/PMLG, DUMBO-1, eDUMBO-122 and LG4) on three different microcrystalline powdered samples (alanine, glycine and β-AspAla) and at three different MAS rates (3.0, 12.5 and 22.0 kHz). Finally, since these sequences can be technically demanding, we describe the experimental protocol we have used to optimize these schemes with the aim to provide simple guidelines for the optimization of CRAMPS experiments for all NMR users.
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Affiliation(s)
- Federico M Paruzzo
- Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Lyndon Emsley
- Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland.
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4
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Haimovich A, Goldbourt A. How does the mood stabilizer lithium bind ATP, the energy currency of the cell: Insights from solid-state NMR. Biochim Biophys Acta Gen Subj 2019; 1864:129456. [PMID: 31678143 DOI: 10.1016/j.bbagen.2019.129456] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 10/07/2019] [Accepted: 10/24/2019] [Indexed: 12/11/2022]
Abstract
BACKGROUND Lithium, in the form of a salt, is a mood stabilizer and a leading drug for the treatment of bipolar disorder. It has a very narrow therapeutic range and a variety of side effects. Lithium can replace magnesium and other cations in enzymes and small molecules, among them ATP, thereby affecting and inhibiting many biochemical pathways. The form of binding of lithium ions to ATP is not known. METHODS Here we extract the binding environment of lithium in solid ATP using a multi-nuclear multi-dimensional solid-state NMR approach. RESULTS We determine that the coordination sphere of lithium includes, at a distance of 3.0(±0.4) Å, three phosphates; the two phosphates closest to the ribose ring from one ATP molecule, and the middle phosphate from another ATP molecule. A water molecule most probably completes the fourth coordination. Despite the use of excess lithium in the preparations, sodium ions still remain bound to the sample, at distances of 4.3-5.5 Å from Li, and coordinate the first phosphate and two terminal phosphates. CONCLUSIONS Solid-state NMR enables to unravel the exact coordination of lithium in ATP showing binding to three phosphates from two molecules, none of which are the terminal gamma phosphate. GENERAL SIGNIFICANCE The methods we use are applicable to study lithium bound to a variety of ATP-bound enzymes, or to other cellular targets of lithium, consequently suggesting a molecular basis for its mode of action.
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Affiliation(s)
- A Haimovich
- School of Chemistry, Tel Aviv University, Tel Aviv 6997801, Israel
| | - A Goldbourt
- School of Chemistry, Tel Aviv University, Tel Aviv 6997801, Israel.
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5
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Sternberg U, Witter R, Kuprov I, Lamley JM, Oss A, Lewandowski JR, Samoson A. 1H line width dependence on MAS speed in solid state NMR - Comparison of experiment and simulation. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 291:32-39. [PMID: 29679841 DOI: 10.1016/j.jmr.2018.04.003] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 04/04/2018] [Accepted: 04/06/2018] [Indexed: 06/08/2023]
Abstract
Recent developments in magic angle spinning (MAS) technology permit spinning frequencies of ≥100 kHz. We examine the effect of such fast MAS rates upon nuclear magnetic resonance proton line widths in the multi-spin system of β-Asp-Ala crystal. We perform powder pattern simulations employing Fokker-Plank approach with periodic boundary conditions and 1H-chemical shift tensors calculated using the bond polarization theory. The theoretical predictions mirror well the experimental results. Both approaches demonstrate that homogeneous broadening has a linear-quadratic dependency on the inverse of the MAS spinning frequency and that, at the faster end of the spinning frequencies, the residual spectral line broadening becomes dominated by chemical shift distributions and susceptibility effects even for crystalline systems.
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Affiliation(s)
- Ulrich Sternberg
- Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany; COSMOS GbR, Jena, Germany.
| | - Raiker Witter
- School of Information Technologies, Tallinn University of Technology, Tallinn, Estonia; Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany; NMR Institute MTÜ, Tallinn, Estonia
| | - Ilya Kuprov
- School of Chemistry, University of Southampton, UK
| | | | - Andres Oss
- School of Information Technologies, Tallinn University of Technology, Tallinn, Estonia; NMR Institute MTÜ, Tallinn, Estonia
| | | | - Ago Samoson
- School of Information Technologies, Tallinn University of Technology, Tallinn, Estonia; NMR Institute MTÜ, Tallinn, Estonia
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6
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Mote KR, Madhu PK. Simultaneous homonuclear and heteronuclear spin decoupling in magic-angle spinning solid-state NMR. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2018; 90:7-12. [PMID: 29370958 DOI: 10.1016/j.ssnmr.2018.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 01/08/2018] [Accepted: 01/09/2018] [Indexed: 06/07/2023]
Abstract
We show here an effective way of implementing simultaneously homonuclear and heteronuclear dipolar decoupling in magic-angle spinning (MAS) solid-state NMR. Whilst the homonuclear spin decoupling is applied on the 1H channel, heteronuclear spin decoupling is applied on the 13C channel. The 1H spins are observed in a windowed fashion in this case. The resultant 1H spectrum has higher resolution due to the attenuation of broadening arising from both homonuclear 1H-1H and heteronuclear 1H-13C interactions, with the latter normally leading to additional line broadening in 13C labelled samples. The experiments are performed at MAS frequencies of ca. 60 kHz.
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Affiliation(s)
- Kaustubh R Mote
- Tata Institute of Fundamental Research Hyderabad, Survey No. 36/P, Gopanapally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad, 500 107, India.
| | - Perunthiruthy K Madhu
- Tata Institute of Fundamental Research Hyderabad, Survey No. 36/P, Gopanapally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad, 500 107, India; Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai, 400 005, India.
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7
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Mote KR, Agarwal V, Madhu PK. Five decades of homonuclear dipolar decoupling in solid-state NMR: Status and outlook. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2016; 97:1-39. [PMID: 27888838 DOI: 10.1016/j.pnmrs.2016.08.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 07/11/2016] [Accepted: 08/02/2016] [Indexed: 06/06/2023]
Abstract
It has been slightly more than fifty years since the first homonuclear spin decoupling scheme, Lee-Goldburg decoupling, was proposed for removing homonuclear dipolar interactions in solid-state nuclear magnetic resonance. A family of such schemes has made observation of high-resolution NMR spectra of abundant spins possible in various applications in solid state. This review outlines the strategies used in this field and the future prospects of homonuclear spin decoupling in solid-state NMR.
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Affiliation(s)
- Kaustubh R Mote
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research, 21 Brundavan Colony, Narsingi, Hyderabad 500 075, India
| | - Vipin Agarwal
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research, 21 Brundavan Colony, Narsingi, Hyderabad 500 075, India
| | - P K Madhu
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research, 21 Brundavan Colony, Narsingi, Hyderabad 500 075, India; Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400 005, India
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8
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Sharma K, Madhu PK, Mote KR. A suite of pulse sequences based on multiple sequential acquisitions at one and two radiofrequency channels for solid-state magic-angle spinning NMR studies of proteins. JOURNAL OF BIOMOLECULAR NMR 2016; 65:127-141. [PMID: 27364976 DOI: 10.1007/s10858-016-0043-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 06/14/2016] [Indexed: 05/04/2023]
Abstract
One of the fundamental challenges in the application of solid-state NMR is its limited sensitivity, yet a majority of experiments do not make efficient use of the limited polarization available. The loss in polarization in a single acquisition experiment is mandated by the need to select out a single coherence pathway. In contrast, sequential acquisition strategies can encode more than one pathway in the same experiment or recover unused polarization to supplement a standard experiment. In this article, we present pulse sequences that implement sequential acquisition strategies on one and two radiofrequency channels with a combination of proton and carbon detection to record multiple experiments under magic-angle spinning. We show that complementary 2D experiments such as [Formula: see text] and [Formula: see text] or DARR and [Formula: see text], and 3D experiments such as [Formula: see text] and [Formula: see text], or [Formula: see text] and [Formula: see text] can be combined in a single experiment to ensure time savings of at least 40 %. These experiments can be done under fast or slow-moderate magic-angle spinning frequencies aided by windowed [Formula: see text] acquisition and homonulcear decoupling. The pulse sequence suite is further expanded by including pathways that allow the recovery of residual polarization, the so-called 'afterglow' pathways, to encode a number of pulse sequences to aid in assignments and chemical-shift mapping.
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Affiliation(s)
- Kshama Sharma
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research, Hyderabad, 21, Brundavan Colony, Narsingi, Hyderabad, 500 075, India
| | - Perunthiruthy K Madhu
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research, Hyderabad, 21, Brundavan Colony, Narsingi, Hyderabad, 500 075, India.
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai, 400 005, India.
| | - Kaustubh R Mote
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research, Hyderabad, 21, Brundavan Colony, Narsingi, Hyderabad, 500 075, India.
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9
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Mote KR, Madhu PK. Proton-detected solid-state NMR spectroscopy of fully protonated proteins at slow to moderate magic-angle spinning frequencies. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2015; 261:149-56. [PMID: 26580064 DOI: 10.1016/j.jmr.2015.10.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 10/11/2015] [Accepted: 10/20/2015] [Indexed: 06/05/2023]
Abstract
(1)H-detection offers a substitute to the sensitivity-starved experiments often used to characterize biomolecular samples using magic-angle spinning solid-state NMR spectroscopy (MAS-ssNMR). To mitigate the effects of the strong (1)H-(1)H dipolar coupled network that would otherwise severely broaden resonances, high MAS frequencies (>40kHz) are often employed. Here, we have explored the alternative of stroboscopic (1)H-detection at moderate MAS frequencies of 5-30kHz using windowed version of supercycled-phase-modulated Lee-Goldburg homonuclear decoupling. We show that improved resolution in the (1)H dimension, comparable to that obtainable at high spinning frequencies of 40-60kHz without homonuclear decoupling, can be obtained in these experiments for fully protonated proteins. Along with detailed analysis of the performance of the method on the standard tri-peptide f-MLF, experiments on micro-crystalline GB1 and amyloid-β aggregates are used to demonstrate the applicability of these pulse-sequences to challenging biomolecular systems. With only two parameters to optimize, broadbanded performance of the homonuclear decoupling sequence, linear dependence of the chemical-shift scaling factor on resonance offset and a straightforward implementation under experimental conditions currently used for many biomolecular studies (viz. spinning frequencies and radio-frequency amplitudes), we expect these experiments to complement the current (13)C-detection based methods in assignments and characterization through chemical-shift mapping.
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Affiliation(s)
- Kaustubh R Mote
- TIFR Center for Interdisciplinary Sciences, Tata Institute of Fundamental Research Hyderabad, 21 Brundavan Colony, Narsingi, Hyderabad 500075, India.
| | - Perunthiruthy K Madhu
- TIFR Center for Interdisciplinary Sciences, Tata Institute of Fundamental Research Hyderabad, 21 Brundavan Colony, Narsingi, Hyderabad 500075, India; Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India.
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10
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Brouwer DH, Horvath M. Minimizing the effects of RF inhomogeneity and phase transients allows resolution of two peaks in the (1)H CRAMPS NMR spectrum of adamantane. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2015; 71:30-40. [PMID: 26483329 DOI: 10.1016/j.ssnmr.2015.10.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 09/23/2015] [Accepted: 10/07/2015] [Indexed: 06/05/2023]
Abstract
One of the limiting factors to achieving highly resolved (1)H NMR spectra with (1)H homonuclear decoupling sequences is imperfections in the applied radiofrequency (RF) pulses, most notably phase transients and RF inhomogeneity. Through a series of simulations and solid-state NMR experiments, it is demonstrated that the combined effects of phase transients and RF inhomogeneity can be minimized by a combination of (i) restricting the sample to small volume of the rotor, (ii) by employing a super-cycled version of the DUMBO decoupling sequence, and (iii) by carefully adjusting the probe tuning such that the asymmetric component of phase transients is minimized. Under these optimal conditions, it was possible to clearly resolve two signals in the (1)H CRAMPS NMR spectrum of adamantane arising from the CH and CH2 protons in the molecule. It is proposed that adamantane could be a very useful setup sample for (1)H CRAMPS NMR as the two peaks are only resolved when the effects of RF inhomogeneity and phase transients are minimized.
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Affiliation(s)
- Darren H Brouwer
- Department of Chemistry, Redeemer University College, Ancaster, ON, Canada L9K 1J4.
| | - Matthew Horvath
- Department of Chemistry, Redeemer University College, Ancaster, ON, Canada L9K 1J4
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11
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Haimovich A, Goldbourt A. Characterization of lithium coordination sites with magic-angle spinning NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2015; 254:131-138. [PMID: 25899290 DOI: 10.1016/j.jmr.2015.02.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Revised: 01/28/2015] [Accepted: 02/07/2015] [Indexed: 06/04/2023]
Abstract
Lithium, in the form of lithium carbonate, is one of the most common drugs for bipolar disorder. Lithium is also considered to have an effect on many other cellular processes hence it possesses additional therapeutic as well as side effects. In order to quantitatively characterize the binding mode of lithium, it is required to identify the interacting species and measure their distances from the metal center. Here we use magic-angle spinning (MAS) solid-state NMR to study the binding site of lithium in complex with glycine and water (LiGlyW). Such a compound is a good enzyme mimetic since lithium is four-coordinated to one water molecule and three carboxylic groups. Distance measurements to carbons are performed using a 2D transferred echo double resonance (TEDOR) MAS solid-state NMR experiment, and water binding is probed by heteronuclear high-resolution proton-lithium and proton-carbon correlation (wPMLG-HETCOR) experiments. Both HETCOR experiments separate the main complex from impurities and non-specifically bound lithium species, demonstrating the sensitivity of the method to probe the species in the binding site. Optimizations of the TEDOR pulse scheme in the case of a quadrupolar nucleus with a small quadrupole coupling constant show that it is most efficient when pulses are positioned on the spin-1/2 (carbon-13) nucleus. Since the intensity of the TEDOR signal is not normalized, careful data analysis that considers both intensity and dipolar oscillations has to be performed. Nevertheless we show that accurate distances can be extracted for both carbons of the bound glycine and that these distances are consistent with the X-ray data and with lithium in a tetrahedral environment. The lithium environment in the complex is very similar to the binding site in inositol monophosphatase, an enzyme associated with bipolar disorder and the putative target for lithium therapy. A 2D TEDOR experiment applied to the bacterial SuhB gene product of this enzyme was designed to probe direct correlations between lithium, the enzyme inhibitor, and the closest carboxyl carbons of the binding site. At this point, the chemical shift of the bound carboxyl groups in this 29 kDa enzyme could be determined.
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Affiliation(s)
- A Haimovich
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv 69978, Tel Aviv, Israel
| | - A Goldbourt
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv 69978, Tel Aviv, Israel.
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12
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Shen M, Trébosc J, Lafon O, Pourpoint F, Hu B, Chen Q, Amoureux JP. Improving the resolution in proton-detected through-space heteronuclear multiple quantum correlation NMR spectroscopy. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2014; 245:38-49. [PMID: 24929867 DOI: 10.1016/j.jmr.2014.05.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Revised: 05/02/2014] [Accepted: 05/05/2014] [Indexed: 06/03/2023]
Abstract
Connectivities and proximities between protons and low-gamma nuclei can be probed in solid-state NMR spectroscopy using two-dimensional (2D) proton-detected heteronuclear correlation, through Heteronuclear Multiple Quantum Correlation (HMQC) pulse sequence. The indirect detection via protons dramatically enhances the sensitivity. However, the spectra are often broadened along the indirect F1 dimension by the decay of heteronuclear multiple-quantum coherences under the strong (1)H-(1)H dipolar couplings. This work presents a systematic comparison of the performances of various decoupling schemes during the indirect t1 evolution period of dipolar-mediated HMQC (D-HMQC) experiment. We demonstrate that (1)H-(1)H dipolar decoupling sequences during t1, such as symmetry-based schemes, phase-modulated Lee-Goldburg (PMLG) and Decoupling Using Mind-Boggling Optimization (DUMBO), provide better resolution than continuous wave (1)H irradiation. We also report that high resolution requires the preservation of (1)H isotropic chemical shifts during the decoupling sequences. When observing indirectly broad spectra presenting numerous spinning sidebands, the D-HMQC sequence must be fully rotor-synchronized owing to the rotor-synchronized indirect sampling and dipolar recoupling sequence employed. In this case, we propose a solution to reduce artefact sidebands caused by the modulation of window delays before and after the decoupling application during the t1 period. Moreover, we show that (1)H-(1)H dipolar decoupling sequence using Smooth Amplitude Modulation (SAM) minimizes the t1-noise. The performances of the various decoupling schemes are assessed via numerical simulations and compared to 2D (1)H-{(13)C} D-HMQC experiments on [U-(13)C]-L-histidine⋅HCl⋅H2O at various magnetic fields and Magic Angle spinning (MAS) frequencies. Great resolution and sensitivity enhancements resulting from decoupling during t1 period enable the detection of heteronuclear correlation between aliphatic protons and ammonium (14)N sites in L-histidine⋅HCl⋅H2O.
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Affiliation(s)
- Ming Shen
- Physics Department & Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062, China; UCCS, University Lille North of France, Villeneuve d'Ascq 59652, France
| | - J Trébosc
- UCCS, University Lille North of France, Villeneuve d'Ascq 59652, France
| | - O Lafon
- UCCS, University Lille North of France, Villeneuve d'Ascq 59652, France
| | - F Pourpoint
- UCCS, University Lille North of France, Villeneuve d'Ascq 59652, France
| | - Bingwen Hu
- Physics Department & Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062, China
| | - Qun Chen
- Physics Department & Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062, China
| | - J-P Amoureux
- Physics Department & Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062, China; UCCS, University Lille North of France, Villeneuve d'Ascq 59652, France.
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13
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Goldbourt A. Distance Measurements to Metal Ions and Other Quadrupolar Spins by Magic Angle Spinning Solid State NMR. Isr J Chem 2014. [DOI: 10.1002/ijch.201300108] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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14
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Halse ME, Schlagnitweit J, Emsley L. High-Resolution1H Solid-State NMR Spectroscopy Using Windowed LG4 Homonuclear Dipolar Decoupling. Isr J Chem 2014. [DOI: 10.1002/ijch.201300101] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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15
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Mithu VS, Tan KO, Madhu PK. Selective inversion of 1H resonances in solid-state nuclear magnetic resonance: Use of double-DANTE pulse sequence. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2013; 237:11-16. [PMID: 24121475 DOI: 10.1016/j.jmr.2013.09.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 09/07/2013] [Accepted: 09/16/2013] [Indexed: 06/02/2023]
Abstract
We here present a method based on DANTE pulses and homonuclear dipolar decoupling scheme to invert selectively any desired resonance in a proton spin system under magic-angle spinning. Experimental results are reported on a sample of L-histidine·HCl·H2O at magic-angle spinning frequencies of 15 and 60kHz. The results are also substantiated numerically.
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Affiliation(s)
- Venus Singh Mithu
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400 005, India
| | - Kong Ooi Tan
- Department of Physical Chemistry, ETH Zurich, CH-8093 Zurich, Switzerland
| | - P K Madhu
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400 005, India; TIFR Centre for Interdisciplinary Sciences, 21 Brundavan Colony, Narsinghi, Hyderabad 500 075, India.
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Halse ME, Emsley L. Improved Phase-Modulated Homonuclear Dipolar Decoupling for Solid-State NMR Spectroscopy from Symmetry Considerations. J Phys Chem A 2013; 117:5280-90. [DOI: 10.1021/jp4038733] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Meghan E. Halse
- Centre de RMN à Très
Hauts Champs, Institut
de Sciences Analytiques (CNRS/ENS-Lyon/UCB Lyon 1), Université de Lyon, 5 rue de la Doua, 69100 Villeurbanne, France
| | - Lyndon Emsley
- Centre de RMN à Très
Hauts Champs, Institut
de Sciences Analytiques (CNRS/ENS-Lyon/UCB Lyon 1), Université de Lyon, 5 rue de la Doua, 69100 Villeurbanne, France
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17
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Lu X, Lafon O, Trébosc J, Thankamony ASL, Nishiyama Y, Gan Z, Madhu PK, Amoureux JP. Detailed analysis of the TIMES and TIMES0 high-resolution MAS methods for high-resolution proton NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2012; 223:219-227. [PMID: 22985982 DOI: 10.1016/j.jmr.2012.07.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Revised: 07/19/2012] [Accepted: 07/22/2012] [Indexed: 06/01/2023]
Abstract
We analyze and compare the specifications of TIMES and TIMES(0) proton high-resolution NMR methods for solid-state samples. This comparison is performed in terms of resolution versus magic-angle spinning (MAS) spinning speed, ν(R), rf-field amplitude, ν(1), and tilt-angle for the effective rf-field, θ(p). The chemical-shift and homo-nuclear dipolar scaling factors are calculated for both methods. For all MAS speeds, the best resolution is always observed with rf-field of ν(1)≈120-130 kHz. At slow MAS speed (ν(R)≤10 kHz), the best resolution is observed for a tilt-angle of θ(P)≈90°. At moderate spinning speed (15≤ν(R)≤35 kHz), θ(P)≈55° gives the best resolution. At higher MAS speed (ν(R)≥60 kHz), with TIMES and TIMES(0) the best resolution is obtained for θ(P)≤40°; but we then recommend TIMES(0), owing to its simpler set-up. We also show that in addition to the usual high rf-field regime (ν(1)≈120-130 kHz), another low rf-regime (ν(1)≈40-50 kHz) exists at MAS speed higher than ν(R)≥60 kHz, which also gives a good (1)H resolution. This low rf-regime should be useful for multi-dimensional analyses of bio-molecules with (1)H detection under high-resolution, in order to limit the heating of the sample.
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Affiliation(s)
- Xingyu Lu
- UCCS (CNRS-8181), University Lille North of France, Villeneuve d'Ascq 59652, France
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18
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Nishiyama Y, Lu X, Trébosc J, Lafon O, Gan Z, Madhu PK, Amoureux JP. Practical choice of ¹H-¹H decoupling schemes in through-bond ¹H-{X} HMQC experiments at ultra-fast MAS. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2012; 214:151-158. [PMID: 22130518 DOI: 10.1016/j.jmr.2011.10.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Revised: 10/05/2011] [Accepted: 10/28/2011] [Indexed: 05/31/2023]
Abstract
Three (1)H-(1)H homonuclear dipolar decoupling schemes for (1)H indirect detection measurements at very fast MAS are compared. The sequences require the following conditions: (i) being operable at very fast MAS, (ii) a long T(2)(') value, (iii) a large scaling factor, (iv) a small number of adjustable parameters, (v) an acquisition window, (vi) a low rf-power requirement, and (vii) a z-rotation feature. To satisfy these conditions a modified sequence named TIlted Magic-Echo Sandwich with zero degree sandwich pulse (TIMES(0)) is introduced. The basic elements of TIMES(0) consist of one sampling window and two phase-ramped irradiations, which realize alternating positive and negative 360° rotations of (1)H magnetization around an effective field tilted with an angle θ from the B(0) axis. The TIMES(0) sequence benefits from very large chemical shift scaling factors at ultra-fast MAS that reach κ(cs)=0.90 for θ=25° at ν(r)=80kHz MAS and only four adjustable parameters, resulting in easy setup. Long κ(cs)T(2)(') values, where T(2)(') is a irreversible proton transverse relaxation time, greatly enhance the sensitivity in (1)H-{(13)C} through-bond J-HMQC (Heteronuclear Multiple-Quantum Coherence) measurements with (1)H-(1)H decoupling during magnetization transfer periods. Although similar sensitivity can be obtained with through-space D-HMQC sequences, in which (13)C-(1)H dipolar interactions are recoupled, J-HMQC experiments incorporating (1)H-(1)H decoupling benefit from lower t(1)-noise, more uniform excitation of both CH, CH(2) and CH(3) moieties, and easier identification of through-bond connectivities.
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Affiliation(s)
- Yusuke Nishiyama
- JEOL RESONANCE Inc., 3-1-2 Musashino, Akishima, Tokyo 196-8558, Japan.
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Mollica G, Madhu PK, Ziarelli F, Thévand A, Thureau P, Viel S. Towards measurement of homonuclear dipolar couplings in 1H solid-state NMR: recoupling with a rotor-synchronized decoupling scheme. Phys Chem Chem Phys 2012; 14:4359-64. [DOI: 10.1039/c2cp23765b] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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20
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Halse ME, Emsley L. A common theory for phase-modulated homonuclear decoupling in solid-state NMR. Phys Chem Chem Phys 2012; 14:9121-30. [DOI: 10.1039/c2cp40720e] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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21
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Mananga ES, Charpentier T. Introduction of the Floquet-Magnus expansion in solid-state nuclear magnetic resonance spectroscopy. J Chem Phys 2011; 135:044109. [DOI: 10.1063/1.3610943] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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22
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Grimminck DL, Vasa SK, Meerts WL, Kentgens AP, Brinkmann A. EASY-GOING DUMBO on-spectrometer optimisation of phase modulated homonuclear decoupling sequences in solid-state NMR. Chem Phys Lett 2011. [DOI: 10.1016/j.cplett.2011.04.079] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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23
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Siegel R, Mafra L, Rocha J. Improving the 1H indirect dimension resolution of 2D CRAMPS NMR spectra: a simulation and experimental investigation. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2011; 39:81-87. [PMID: 21570264 DOI: 10.1016/j.ssnmr.2011.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Revised: 04/04/2011] [Accepted: 04/05/2011] [Indexed: 05/30/2023]
Abstract
An experimental and simulation investigation regarding the effect of various CRAMPS parameters (delays interleaved with the decoupling shape, z-rotation symmetry and offset frequency) on the DUMBO decoupling performance is presented using two model compounds, glycine and tyrosine·HCl. Although the conclusions of this work may be extended to the other homonuclear-decoupling schemes, this work focuses essentially on the effect of adding interleaved delays to DUMBO decoupling during the indirect dimension using different 2D pulse-scheme architectures. While the simulations revealed an increasing loss of the spectral resolution with longer delays (from 0 to 6 μs), the experimental 2D (1)H DUMBO NMR correlation spectra revealed that the inclusion of delays, during the indirect dimension, improves the (1)H resolution whether the z-rotation symmetry was used or not. The best experimental spectra are obtained when z-rotation symmetry and windows are combined.
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Affiliation(s)
- Renée Siegel
- Department of Chemistry, CICECO, University of Aveiro, 3810-193 Aveiro, Portugal
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24
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A tunable homonuclear dipolar decoupling scheme for high-resolution proton NMR of solids from slow to fast magic-angle spinning. Chem Phys Lett 2011. [DOI: 10.1016/j.cplett.2010.12.070] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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25
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Leskes M, Madhu PK, Vega S. Floquet theory in solid-state nuclear magnetic resonance. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2010; 57:345-380. [PMID: 20920756 DOI: 10.1016/j.pnmrs.2010.06.002] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2010] [Accepted: 06/11/2010] [Indexed: 05/29/2023]
Affiliation(s)
- Michal Leskes
- Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel.
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26
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Paul S, Schneider D, Madhu PK. 1H Homonuclear dipolar decoupling using symmetry-based pulse sequences at ultra fast magic-angle spinning frequencies. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2010; 206:241-245. [PMID: 20727798 DOI: 10.1016/j.jmr.2010.07.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Revised: 07/18/2010] [Accepted: 07/19/2010] [Indexed: 05/29/2023]
Abstract
We demonstrate here the application of symmetry-based pulse sequences for homonuclear dipolar decoupling in solid-state NMR at magic-angle spinning (MAS) frequencies up to 65 kHz using moderate radiofrequency (RF) amplitudes. Theoretical arguments favouring the requirement of low RF amplitudes at high MAS frequencies are given for these sequences. A comparison with wPMLGmmxx¯ is given at 65 kHz of MAS frequency to emphasise that the symmetry-based pulse sequences have a lower RF amplitude requirement at high MAS frequencies.
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Affiliation(s)
- Subhradip Paul
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400 005, India
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27
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Salager E, Dumez JN, Stein RS, Steuernagel S, Lesage A, Elena-Herrmann B, Emsley L. Homonuclear dipolar decoupling with very large scaling factors for high-resolution ultrafast magic angle spinning 1H solid-state NMR spectroscopy. Chem Phys Lett 2010. [DOI: 10.1016/j.cplett.2010.08.038] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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28
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Paul S, Thakur RS, Levitt MH, Madhu PK. 1H homonuclear dipolar decoupling using rotor-synchronised pulse sequences: towards pure absorption phase spectra. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2010; 205:269-275. [PMID: 20570540 DOI: 10.1016/j.jmr.2010.05.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2010] [Revised: 05/11/2010] [Accepted: 05/13/2010] [Indexed: 05/29/2023]
Abstract
We demonstrate a pulse sequence using symmetry-based rotor-synchronised RN(n)(nu) sequences for homonuclear dipolar decoupling that achieves pure absorption phase high-resolution (1)H spectra in solid-state NMR. This sequence is compared with the phase-modulated Lee-Goldburg scheme. Experimental results are shown for samples of glycine and L-histidine.HCl.H(2)O for magic-angle-spinning frequencies in the range of 14-30 kHz and at two different magnetic fields.
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Affiliation(s)
- Subhradip Paul
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400 005, India
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29
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Khan M, Enkelmann V, Brunklaus G. Crystal Engineering of Pharmaceutical Co-crystals: Application of Methyl Paraben as Molecular Hook. J Am Chem Soc 2010; 132:5254-63. [DOI: 10.1021/ja100146f] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mujeeb Khan
- Max-Planck-Institut für Polymerforschung, Postfach 31 48, D-55021 Mainz, Germany
| | - Volker Enkelmann
- Max-Planck-Institut für Polymerforschung, Postfach 31 48, D-55021 Mainz, Germany
| | - Gunther Brunklaus
- Max-Planck-Institut für Polymerforschung, Postfach 31 48, D-55021 Mainz, Germany
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30
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Wang Q, Hu B, Lafon O, Trébosc J, Deng F, Amoureux JP. Homonuclear dipolar recoupling under ultra-fast magic-angle spinning: probing 19F-19F proximities by solid-state NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2010; 203:113-128. [PMID: 20044288 DOI: 10.1016/j.jmr.2009.12.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2009] [Revised: 12/09/2009] [Accepted: 12/09/2009] [Indexed: 05/28/2023]
Abstract
We describe dipolar recoupling methods that accomplish, at high magic-angle spinning (MAS) frequencies, the excitation of double-quantum (DQ) coherences between spin-1/2 nuclei. We employ rotor-synchronized symmetry-based pulse sequences which are either gamma-encoded or non-gamma-encoded. The sensitivity and the robustness to both chemical-shift anisotropy and offset are examined. We also compare different techniques to avoid signal folding in the indirect dimension of two-dimensional double-quantum<-->single-quantum (DQ-SQ) spectra. This comprehensive analysis results in the identification of satisfactory conditions for dipolar (19)F-(19)F recoupling at high magnetic fields and high MAS frequencies. The utility of these recoupling methods is demonstrated with high-resolution DQ-SQ NMR spectra, which allow probing (19)F-(19)F proximities in powered fluoroaluminates.
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Affiliation(s)
- Qiang Wang
- UCCS, CNRS-8181, Lille-University, 59652, Villeneuve d'Ascq, France; State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance, WIPM, Chinese Academy of Sciences, Wuhan 430071, China; Graduate School of the Chinese Academy of Sciences, Beijing, China
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31
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Mao K, Pruski M. Homonuclear dipolar decoupling under fast MAS: resolution patterns and simple optimization strategy. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2010; 203:144-149. [PMID: 20093059 DOI: 10.1016/j.jmr.2009.12.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2009] [Revised: 12/14/2009] [Accepted: 12/14/2009] [Indexed: 05/28/2023]
Abstract
A simple method is shown for optimization of (1)H homonuclear dipolar decoupling at MAS rates exceeding 10 kHz. By monitoring the intensity of a spin-echo under the decoupling conditions, it is possible to optimize the amplitude of the RF magnetic field, the cycle time of the decoupling sequence and the resonance offset within minutes. As a result, the decoupling efficiency can be quickly and reliably fine-tuned without using a reference sample. The utility of this method has been confirmed by studying the resolution patterns for the supercycled PMLG scheme, which were found to be in excellent agreement with earlier theoretical predictions and verified in high-resolution 2D (1)H-(1)H experiments.
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Affiliation(s)
- Kanmi Mao
- Ames Laboratory, Iowa State University, Ames, IA 50011-3020, USA
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32
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Cavadini S. Indirect detection of nitrogen-14 in solid-state NMR spectroscopy. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2010; 56:46-77. [PMID: 20633348 DOI: 10.1016/j.pnmrs.2009.08.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2009] [Accepted: 08/12/2009] [Indexed: 05/29/2023]
Affiliation(s)
- Simone Cavadini
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne, Batochime, Lausanne, Switzerland.
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33
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Cavadini S, Vitzthum V, Ulzega S, Abraham A, Bodenhausen G. Line-narrowing in proton-detected nitrogen-14 NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2010; 202:57-63. [PMID: 19853485 DOI: 10.1016/j.jmr.2009.09.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Revised: 09/28/2009] [Accepted: 09/28/2009] [Indexed: 05/28/2023]
Abstract
In solids spinning at the magic angle, the indirect detection of single-quantum (SQ) and double-quantum (DQ) (14)N spectra (I=1) via spy nuclei S=1/2 such as protons can be achieved in the manner of heteronuclear single- or multiple-quantum correlation (HSQC or HMQC) spectroscopy. The HMQC method relies on the excitation of two-spin coherences of the type T(11)(I)T(11)(S) and T(21)(I)T(11)(S) at the beginning of the evolution interval t(1). The spectra obtained by Fourier transformation from t(1) to omega(1) may be broadened by the homogenous decay of the transverse terms of the spy nuclei S. This broadening is mostly due to homonuclear dipolar S-S' interactions between the proton spy nuclei. In this work we have investigated the possibility of inserting rotor-synchronized symmetry-based C or R sequences and decoupling schemes such as Phase-Modulated Lee-Goldburg (PMLG) sequences in the evolution period. These schemes reduce the homonuclear proton-proton interactions and lead to an enhancement of the resolution of both SQ and DQ proton-detected (14)N HMQC spectra. In addition, we have investigated the combination of HSQC with symmetry-based sequences and PMLG and shown that the highest resolution in the (14)N dimension is achieved by using HSQC in combination with symmetry-based sequences of the R-type. We show improvements in resolution in samples of l-alanine and the tripeptide ala-ala-gly (AAG). In particular, for l-alanine the width of the (14)N SQ peak is reduced from 2 to 1.2 kHz, in agreement with simulations. We report accurate measurements of quadrupolar coupling constants and asymmetry parameters for amide (14)N in AAG peptide bonds.
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Affiliation(s)
- Simone Cavadini
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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34
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Leskes M, Madhu PK, Vega S. Why does PMLG proton decoupling work at 65kHz MAS? JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2009; 199:208-213. [PMID: 19482494 DOI: 10.1016/j.jmr.2009.05.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2009] [Revised: 05/03/2009] [Accepted: 05/04/2009] [Indexed: 05/27/2023]
Abstract
Schemes such as phase-modulated Lee-Goldburg (PMLG) for homonuclear dipolar decoupling have been shown to yield high-resolution (1)H spectra at high magic-angle spinning (MAS) frequencies of 50-70kHz. This is at variance to the commonly held notion that these methods require MAS frequencies not comparable to the cycle frequencies of the pulse schemes. Here, a theoretical argument, based on bimodal Floquet theory, is presented to explain this aspect together with conditions where PMLG type of schemes may be successful at high MAS frequencies.
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Affiliation(s)
- Michal Leskes
- Department of Chemical Physics, Weizmann Institute of Science, Rehovot, Israel
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35
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Bradley JP, Tripon C, Filip C, Brown SP. Determining relative proton-proton proximities from the build-up of two-dimensional correlation peaks in 1H double-quantum MAS NMR: insight from multi-spin density-matrix simulations. Phys Chem Chem Phys 2009; 11:6941-52. [PMID: 19652828 DOI: 10.1039/b906400a] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The build-up of intensity-as a function of the number, n(rcpl), of POST-C7 elements used for the excitation and reconversion of double-quantum (DQ) coherence (DQC)-is analysed for the fifteen distinct DQ correlation peaks that are observed experimentally for the eight separate (1)H resonances in a (1)H (500 MHz) DQ CRAMPS solid-state (12.5 kHz MAS) NMR spectrum of the dipeptide beta-AspAla (S. P. Brown, A. Lesage, B. Elena, and L. Emsley, J. Am. Chem. Soc., 2004, 126, 13230). The simulation in SPINEVOLUTION (M. Veshtort and R. G. Griffin, J. Magn. Reson., 2006, 178, 248) of t(1) ((1)H DQ evolution) FIDs for clusters of eight dipolar-coupled protons gives separate simulated (1)H DQ build-up curves for the CH(2)(a), CH(2)(b), CH(Asp), CH(Ala), NH and OH (1)H single-quantum (SQ) (1)H resonances. An analysis of both the simulated and experimental (1)H DQ build-up leads to the following general observations: (i) considering the build-up of (1)H DQ peaks at a particular SQ frequency, maximum intensity is observed for the DQC corresponding to the shortest H-H distance; (ii) for the maximum intensity (1)H DQ peak at a particular SQ frequency, the recoupling time for the observed maximum intensity depends on the corresponding H-H distance, e.g., maximum intensity for the CH(2)(a)-CH(2)(b) (H-H distance = 1.55 A) and OH-CH(Asp) (H-H distance = 2.49 A) DQ peaks is observed at n(rcpl) = 2 and 3, respectively; (iii) for DQ peaks involving a CH(2) proton at a non-CH(2) SQ frequency, there is much reduced intensity and a maximum intensity at a short recoupling time; (iv) for the other lower intensity (1)H DQ peaks at a particular SQ frequency, maximum intensity is observed for the same (or close to the same) recoupling time, but the relative intensity of the DQ peaks is a reliable indicator of the relative H-H distance-the ratio of the maximum intensities for the peaks at the CH(Ala) SQ frequency due to the two DQCs with the NH and OH protons are found to be approximately in the ratio of the squares of the corresponding dipolar coupling constants. While the simulated (1)H DQ build-up curves reproduce most of the features of the experimental curves, maximum intensity is often observed at a longer recoupling time in simulations. In this respect, simulations for two to eight spins show a trend towards a faster decay for an increasing number of considered spins. Finally, simulations show that increasing either the Larmor frequency (to 1 GHz) or the MAS frequency (to 125 kHz) does not lead to changes in the marked differences between the (1)H DQ build-up curves at the CH(Asp) SQ frequency for DQCs to the CH(2)(a) and OH protons that correspond to similar H-H distances (2.39 A and 2.49 A, respectively).
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36
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Hu B, Wang Q, Lafon O, Trébosc J, Deng F, Amoureux JP. Robust and efficient spin-locked symmetry-based double-quantum homonuclear dipolar recoupling for probing (1)H-(1)H proximity in the solid-state. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2009; 198:41-48. [PMID: 19185521 DOI: 10.1016/j.jmr.2009.01.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2008] [Revised: 12/19/2008] [Accepted: 01/08/2009] [Indexed: 05/27/2023]
Abstract
We report a novel symmetry-based method, using inversion elements bracketed by spin locks, for exciting double-quantum (DQ) coherences between spin-1/2 nuclei, such as protons. Compared to previous DQ-recoupling techniques, this new pulse sequence requires moderate rf field, even at ultra-fast MAS speeds. Furthermore, it is easy to implement and it displays higher robustness to both chemical shift anisotropy and to spreads in resonance frequencies. These advances greatly facilitate the observation of (1)H-(1)H proximities at high fields and high MAS frequencies.
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Affiliation(s)
- B Hu
- UCCS, CNRS-8181, Lille University, Fr-59652, Villeneuve d'Ascq Cedex, France
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37
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Khan M, Enkelmann V, Brunklaus G. Solid-state NMR and X-ray analysis of structural transformations in O-H...N heterosynthons formed by hydrogen-bond-mediated molecular recognition. J Org Chem 2009; 74:2261-70. [PMID: 19239206 DOI: 10.1021/jo802673f] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The template-mediated, hydrogen-bond-driven co-crystallization of trans-1,2-bis(4-pyridyl)ethylene (bpe) and resorcinol together with 1,2-bis(4-pyridyl)ethane (bpet) yielded two new polymorphs of 2(bpe):2(res) and 2(bpet):2(res) molecular adducts, thereby exploiting the molecular specificity of resorcinol-pyridine O-H...N recognition in the presence of multiple dipyridines. Comprehensive understanding of the subsequent [2 + 2] photodimerization of the known polymorph of 2(bpe):2(res) complex was obtained by applying single-crystal X-ray analysis and (13)C CPMAS solid-state NMR at different levels of conversion, ranging from monomer to the dimer. In addition, removal of the resorcinol template from the 2(bpe):2(res) complex yields a distorted tetrakis(4-pyridyl)cyclobutane, revealing a rather different molecular geometry (orthorhombic, Pccn phase). Ambiguous peak splittings and the presence of unexpected resonances in the respective (13)C CPMAS NMR spectra have been successfully explained by the joint approach of X-ray analysis and density functional theory (DFT) chemical shift computations.
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Affiliation(s)
- Mujeeb Khan
- Max-Planck-Institut fur Polymerforschung, Postfach 31 48, D-55021 Mainz, Germany
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38
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Leskes M, Vega S. Design of a triple quantum coherence excitation scheme for protons in solid state NMR. J Chem Phys 2009; 130:124506. [DOI: 10.1063/1.3098354] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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39
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Paul S, Thakur RS, Goswami M, Sauerwein AC, Mamone S, Concistrè M, Förster H, Levitt MH, Madhu PK. Supercycled homonuclear dipolar decoupling sequences in solid-state NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2009; 197:14-19. [PMID: 19091609 DOI: 10.1016/j.jmr.2008.11.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2008] [Revised: 11/07/2008] [Accepted: 11/18/2008] [Indexed: 05/27/2023]
Abstract
We compare the performance of the windowed phase-modulated Lee-Goldburg (wPMLG) and the windowed decoupling using mind boggling optimisation (wDUMBO) sequences at various magic-angle spinning rates and nutation frequencies of the pulses. Additionally, we introduce a supercycled version of wDUMBO and compare its efficiency with that of the non-supercycled implementation of wDUMBO. The efficiency of the supercycled version of wPMLG, denoted wPMLG-S2, is compared with a new supercycled version of wPMLG that we notate as wPMLG-S3. The interaction between the supercycled homonuclear dipolar decoupling sequences and the sample rotation is analysed using symmetry-based selection rules.
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Affiliation(s)
- Subhradip Paul
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400 005, India
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Enhanced sensitivity in high-resolution 1H solid-state NMR spectroscopy with DUMBO dipolar decoupling under ultra-fast MAS. Chem Phys Lett 2009. [DOI: 10.1016/j.cplett.2008.12.073] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Madhu PK. High-resolution solid-state NMR spectroscopy of protons with homonuclear dipolar decoupling schemes under magic-angle spinning. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2009; 35:2-11. [PMID: 19110404 DOI: 10.1016/j.ssnmr.2008.11.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2008] [Accepted: 11/05/2008] [Indexed: 05/27/2023]
Abstract
High-resolution NMR spectroscopy of (1)H spins in the solid state is normally rendered difficult due to the strong homonuclear (1)H-(1)H dipolar couplings. Even under very high-speed magic-angle spinning (MAS) at ca. 60-70kHz, these couplings are not completely removed. An appropriate radiofrequency pulse scheme is required to average out the homonuclear dipolar interactions in combination with MAS to get high-resolution (1)H NMR spectrum in solid state. Several schemes have been introduced in the recent past with a variety of applications also envisaged. Development of some of these schemes has been made possible with a clear understanding of the underlying spin physics based on bimodal Floquet theory. The utility of these high-resolution pulse schemes in combination with MAS has been demonstrated for spinning speeds of 10-65kHz in a range of (1)H Larmor frequencies from 300 to 800MHz.
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Affiliation(s)
- P K Madhu
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400 005, India.
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Amoureux JP, Hu B, Trébosc J, Wang Q, Lafon O, Deng F. Homonuclear dipolar decoupling schemes for fast MAS. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2009; 35:19-24. [PMID: 19101127 DOI: 10.1016/j.ssnmr.2008.10.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2008] [Revised: 10/28/2008] [Accepted: 10/29/2008] [Indexed: 05/27/2023]
Abstract
We present two one-dimensional methods that allow direct observation of highly resolved (1)H spectra in solid-state NMR. The methods, which work mainly at 30-35kHz MAS speeds, are very robust and efficient. In addition, they present very few false resonances. The windowed smooth amplitude-modulated (wSAM) version has a potential to work at ultra-fast MAS provided the electronics is capable to define the pulse-shape in a smooth way, without any pulse transients.
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Affiliation(s)
- Jean-Paul Amoureux
- UCCS (CNRS-8181), University of Lille-1, Fr-59652 Villeneuve d'Ascq, France.
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Lafon O, Wang Q, Hu B, Trébosc J, Deng F, Amoureux JP. Proton-proton homonuclear dipolar decoupling in solid-state NMR using rotor-synchronized z-rotation pulse sequences. J Chem Phys 2009; 130:014504. [DOI: 10.1063/1.3046479] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Lesage A. Recent advances in solid-state NMR spectroscopy of spin I = 1/2 nuclei. Phys Chem Chem Phys 2009; 11:6876-91. [DOI: 10.1039/b907733m] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Leskes M, Steuernagel S, Schneider D, Madhu P, Vega S. Homonuclear dipolar decoupling at magic-angle spinning frequencies up to 65kHz in solid-state nuclear magnetic resonance. Chem Phys Lett 2008. [DOI: 10.1016/j.cplett.2008.10.029] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Bolz I, Moon C, Enkelmann V, Brunklaus G, Spange S. Probing Molecular Recognition in the Solid-State by Use of an Enolizable Chromophoric Barbituric Acid. J Org Chem 2008; 73:4783-93. [DOI: 10.1021/jo800598z] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ina Bolz
- Institut für Chemie, Technische Universität Chemnitz, D-09107 Chemnitz, Germany, and Max-Planck-Institut für Polymerforschung, Postfach 3148, D-55021 Mainz, Germany
| | - Chulsoon Moon
- Institut für Chemie, Technische Universität Chemnitz, D-09107 Chemnitz, Germany, and Max-Planck-Institut für Polymerforschung, Postfach 3148, D-55021 Mainz, Germany
| | - Volker Enkelmann
- Institut für Chemie, Technische Universität Chemnitz, D-09107 Chemnitz, Germany, and Max-Planck-Institut für Polymerforschung, Postfach 3148, D-55021 Mainz, Germany
| | - Gunther Brunklaus
- Institut für Chemie, Technische Universität Chemnitz, D-09107 Chemnitz, Germany, and Max-Planck-Institut für Polymerforschung, Postfach 3148, D-55021 Mainz, Germany
| | - Stefan Spange
- Institut für Chemie, Technische Universität Chemnitz, D-09107 Chemnitz, Germany, and Max-Planck-Institut für Polymerforschung, Postfach 3148, D-55021 Mainz, Germany
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Paul S, Thakur RS, Madhu P. 1H homonuclear dipolar decoupling at high magic-angle spinning frequencies with rotor-synchronised symmetry sequences. Chem Phys Lett 2008. [DOI: 10.1016/j.cplett.2008.02.111] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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