Solid state nuclear magnetic resonance最新文献

{"title":"Dipolar dephasing for structure determination in a paramagnetic environment","authors":"Rubin Dasgupta,&nbsp;Karthick B.S.S. Gupta,&nbsp;Derek Elam ,&nbsp;Marcellus Ubbink,&nbsp;Huub J.M. de Groot","doi":"10.1016/j.ssnmr.2021.101728","DOIUrl":"10.1016/j.ssnmr.2021.101728","url":null,"abstract":"<div><p>We demonstrate the efficacy of the REDOR-type sequences in determining dipolar coupling strength in a paramagnetic environment. Utilizing paramagnetic effects of enhanced relaxation rates and rapid electronic fluctuations in Cu(II)-(DL-Ala)₂.H₂O, the dipolar coupling for the methyl C–H that is 4.20 ​Å (methyl carbon) away from the Cu²⁺ ion, was estimated to be 8.8 ​± ​0.6 ​kHz. This coupling is scaled by a factor of ~0.3 in comparison to the rigid limit value of ~32 ​kHz, in line with partial averaging of the dipolar interaction by rotational motion of the methyl group. Limited variation in the scaling factor of the dipolar coupling strength at different temperatures is observed. The C–H internuclear distance derived from the size of the dipolar coupling is similar to that observed in the crystal structure. The errors in the dipolar coupling strength observed in the REDOR-type experiments are similar to those reported for diamagnetic systems. Increase in resolution due to the Fermi contact shifts, coupled with MAS frequencies of 30–35 ​kHz allowed to estimate the hyperfine coupling strengths for protons and carbons from the temperature dependence of the chemical shift and obtain a high resolution ¹H–¹H spin diffusion spectrum. This study shows the utility of REDOR-type sequences in obtaining reliable structural and dynamical information from a paramagnetic complex. We believe that this can help in studying the active site of paramagnetic metalloproteins at high resolution.</p></div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":"113 ","pages":"Article 101728"},"PeriodicalIF":3.2,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.ssnmr.2021.101728","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25498679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Separated quadrupole and shift interactions of 2H NMR spectra in paramagnetic solids by asymmetric pulse sequences","authors":"Takahiro Iijima ,&nbsp;Shinobu Ohki ,&nbsp;Masataka Tansho","doi":"10.1016/j.ssnmr.2020.101709","DOIUrl":"10.1016/j.ssnmr.2020.101709","url":null,"abstract":"<div><p>Separated pure-quadrupole (PQ) and -shift (PS) spectra of ²<span>H nuclear magnetic resonance (NMR) of paramagnetic solids are obtained and correlated by simple pulse sequences that can acquire the full magnetization under ideal conditions. Two-dimensional NMR signals obtained using an asymmetric </span><em>π</em><span>-pulse-inserted quadrupole-echo (APIQE) sequence yielded separated spectra through the skew operation of an affine transform (AT) before a Fourier transform<span>. Modified APIQE sequences that acquire whole echo signals were fabricated, and separated PQ and PS spectra were obtained by applying a combination of AT, such as rotation and skew operations, to the signal data. These methods were demonstrated for diamagnetic Zn(CD</span></span>₃CO₂)₂⋅2H₂O and paramagnetic Nd(CD₃CO₂)₃⋅1.5H₂O. Further, the dynamics of the D₂O molecule and [Co(D₂O)₆]²⁺<span> ion in paramagnetic CoSiF</span>₆⋅6D₂O was analyzed based on the temperature dependence of the separated spectra.</p></div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":"112 ","pages":"Article 101709"},"PeriodicalIF":3.2,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.ssnmr.2020.101709","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38864017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recent progress in dipolar recoupling techniques under fast MAS in solid-state NMR spectroscopy","authors":"Yi Ji ,&nbsp;Lixin Liang ,&nbsp;Xinhe Bao ,&nbsp;Guangjin Hou","doi":"10.1016/j.ssnmr.2020.101711","DOIUrl":"10.1016/j.ssnmr.2020.101711","url":null,"abstract":"<div><p><span><span>With the recent advances in NMR hardware and probe design technology, magic-angle spinning (MAS) rates over 100 ​kHz are accessible now, even on commercial solid NMR probes. Under such fast MAS conditions, excellent spectral resolution has been achieved by efficient suppression of anisotropic interactions, which also opens an avenue to the proton-detected NMR experiments in solids. Numerous methods have been developed to take full advantage of fast MAS during the last decades. Among them, dipolar recoupling<span> techniques under fast MAS play vital roles in the determination of the molecular structure and dynamics, and are also key elements in multi-dimensional correlation NMR experiments. Herein, we review the dipolar recoupling techniques, especially those developed in the past two decades for fast-to-ultrafast MAS conditions. A major focus for our discussion is the ratio of RF field </span></span>strength (in frequency) to MAS frequency, </span><span><math><mrow><msub><mi>ν</mi><mn>1</mn></msub></mrow></math></span>/<span><math><mrow><msub><mi>ν</mi><mi>r</mi></msub></mrow></math></span>, in different pulse sequences, which determines whether these dipolar recoupling techniques are suitable for NMR experiments under fast MAS conditions. Systematic comparisons are made among both heteronuclear and homonuclear dipolar recoupling schemes. In addition, the schemes developed specially for proton-detection NMR experiments under ultrafast MAS conditions are highlighted as well.</p></div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":"112 ","pages":"Article 101711"},"PeriodicalIF":3.2,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.ssnmr.2020.101711","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38872026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recent developments in deuterium solid-state NMR for the detection of slow motions in proteins","authors":"Liliya Vugmeyster","doi":"10.1016/j.ssnmr.2020.101710","DOIUrl":"10.1016/j.ssnmr.2020.101710","url":null,"abstract":"<div><p><span><span>Slow timescale dynamics in proteins are essential for a variety of biological functions spanning ligand binding, enzymatic catalysis, </span>protein folding and misfolding regulations, as well as protein–protein and protein–nucleic acid interactions. In this review, we focus on the experimental and theoretical developments of </span>²H static NMR methods applicable for studies of microsecond to millisecond motional modes in proteins, particularly rotating frame relaxation dispersion (<em>R</em>_1ρ<span>), quadrupolar Carr–Purcell–Meiboom–Gill (QCPMG) relaxation dispersion, and quadrupolar chemical exchange saturation transfer<span> NMR experiments (Q-CEST). With applications chosen from amyloid-β fibrils, we show the complementarity of these approaches for elucidating the complexities of conformational ensembles in disordered domains in the non-crystalline solid state, with the employment of selective deuterium labels. Combined with recent advances in relaxation dispersion backbone measurements for </span></span>¹⁵N/¹³C/¹H nuclei, these techniques provide powerful tools for studies of biologically relevant timescale dynamics in disordered domains in the solid state.</p></div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":"111 ","pages":"Article 101710"},"PeriodicalIF":3.2,"publicationDate":"2021-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.ssnmr.2020.101710","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38826956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"1H/13C/15N triple-resonance experiments for structure determinaton of membrane proteins by oriented-sample NMR","authors":"Joel Lapin,&nbsp;Emmanuel O. Awosanya,&nbsp;Richard J.A. Esteves,&nbsp;Alexander A. Nevzorov","doi":"10.1016/j.ssnmr.2020.101701","DOIUrl":"10.1016/j.ssnmr.2020.101701","url":null,"abstract":"<div><p>The benefits of triple-resonance experiments for structure determination of macroscopically oriented membrane proteins by solid-state NMR are discussed. While double-resonance ¹H/¹⁵<span>N experiments are effective for structure elucidation of alpha-helical domains, extension of the method of oriented samples to more complex topologies and assessing side-chain conformations necessitates further development of triple-resonance (</span>¹H/¹³C/¹⁵N) NMR pulse sequences. Incorporating additional spectroscopic dimensions involving ¹³C spin-bearing nuclei, however, introduces essential complications arising from the wide frequency range of the ¹H-¹³<span>C dipolar couplings and </span>¹³<span>C CSA (&gt;20 ​kHz), and the presence of the </span>¹³C-¹³C homonuclear dipole-dipole interactions. The recently reported ROULETTE–CAHA pulse sequence, in combination with the selective z-filtering, can be used to evolve the structurally informative ¹H-¹³<span>C dipolar coupling arising from the aliphatic carbons while suppressing the signals from the carbonyl and methyl regions. Proton-mediated magnetization transfer under mismatched Hartman-Hahn conditions (MMHH) can be used to correlate </span>¹³C and ¹⁵N nuclei in such triple-resonance experiments for the subsequent ¹⁵<span>N detection. The recently developed pulse sequences are illustrated for n-acetyl Leucine<span> (NAL) single crystal and doubly labeled Pf1 coat protein reconstituted in magnetically aligned bicelles. An interesting observation is that in the case of </span></span>¹⁵N-labeled NAL measured at ¹³C natural abundance, the triple (¹H/¹³C/¹⁵N) MMHH scheme predominantly gives rise to long-range intermolecular magnetization transfers from ¹³C to ¹⁵N spins; whereas direct Hartmann-Hahn ¹³C/¹⁵N transfer is entirely intramolecular. The presented developments advance NMR of oriented samples for structure determination of membrane proteins and liquid crystals.</p></div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":"111 ","pages":"Article 101701"},"PeriodicalIF":3.2,"publicationDate":"2021-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.ssnmr.2020.101701","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38661792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phase-sensitive γ-encoded recoupling of heteronuclear dipolar interactions and 1H chemical shift anisotropy","authors":"Frédéric A. Perras,&nbsp;Alexander L. Paterson,&nbsp;Takeshi Kobayashi","doi":"10.1016/j.ssnmr.2020.101712","DOIUrl":"10.1016/j.ssnmr.2020.101712","url":null,"abstract":"<div><p>γ-encoded recoupling sequences are known to produce strong amplitude modulations that lead to sharp doublets when Fourier transformed. These doublets depend very little on the recoupled tensor asymmetry and thus enable for the straightforward determination of dynamic order parameters. It can, however, be difficult to measure small anisotropies, or small order parameters, using such sequences; the resonances from the doublet may overlap with each other, or with the zero-frequency glitch. This limitation has prevented the widespread use of ¹<span>H chemical shift anisotropy (CSA) for the measurement of dynamics, particularly for CH protons which typically have CSAs of only a few ppm when immobile. Here, we introduce a simple modification to the traditional </span>¹H CSA and proton-detected local field pulse sequences that enables the acquisition of a hypercomplex dataset and the removal of the uncorrelated magnetization that results in the zero-frequency glitch. These new sequences then yield a frequency shift in the indirect dimension, rather than a splitting, which is easily identifiable even in cases of weak interactions.</p></div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":"111 ","pages":"Article 101712"},"PeriodicalIF":3.2,"publicationDate":"2021-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.ssnmr.2020.101712","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38826957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hyperpolarisation techniques","authors":"Ryan E. Mewis","doi":"10.1039/9781839164965-00151","DOIUrl":"https://doi.org/10.1039/9781839164965-00151","url":null,"abstract":"","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":"68 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86793160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Applications of solid-state NMR spectroscopy in environmental science","authors":"Qian Wang,&nbsp;Ulla Gro Nielsen","doi":"10.1016/j.ssnmr.2020.101698","DOIUrl":"10.1016/j.ssnmr.2020.101698","url":null,"abstract":"<div><p><span><span>Environmental science is an interdisciplinary field, which integrates chemical, physical, and biological sciences to study environmental problems and human impact on the environment. This article highlights the use of solid-state NMR spectroscopy (SSNMR) in studies of environmental processes and remediation with examples from both laboratory studies and samples collected in the field. The contemporary topics presented include soil </span>chemistry, environmental remediation (e.g., heavy metals and </span>radionuclides removal, carbon dioxide mineralization), and phosphorus recovery. SSNMR is a powerful technique, which provides atomic-level information about speciation in complex environmental samples as well as the interactions between pollutants and minerals/organic matter on different environmental interfaces. The challenges in the application of SSNMR in environmental science (e.g., measurement of paramagnetic nuclei and low-gamma nuclei) are also discussed, and perspectives are provided for the future research efforts.</p></div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":"110 ","pages":"Article 101698"},"PeriodicalIF":3.2,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.ssnmr.2020.101698","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38558086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural and functional synthesis of the continuous wave NQR temperature sensor with increased conversion linearity","authors":"A. Samila ,&nbsp;I. Safronov ,&nbsp;O. Hotra","doi":"10.1016/j.ssnmr.2020.101700","DOIUrl":"10.1016/j.ssnmr.2020.101700","url":null,"abstract":"<div><p><span><span><span>The paper describes development of the detailed structure and circuit diagrams of the continuous wave NQR </span>temperature sensor with increased conversion linearity. It is experimentally established that at amplitude modulation of 40% and change of input voltage in the range of 20–1000 ​mV, the circuit of a symmetric marginal </span>oscillator<span> with a linear active demodulator provides better linearity of transfer characteristic than the circuits of asymmetric marginal oscillators with JFET<span> or diode detectors. As a thermometric substance of the proposed NQR sensor, copper oxide Cu</span></span></span>₂O was used, which is characterized by a strong temperature dependence of the resonance frequency of ⁶³Cu NQR. In contrast to ³⁵Cl NQR in KClO₃<span>, for cuprous oxide the temperature dependence of </span>⁶³<span>Сu NQR frequency in the frequency range 26.621–25.658 ​MHz is linear in the temperature range 100–390 ​K. It is experimentally confirmed that the use of a low mass sample (less than 200 ​mg) as a thermometric substance of the proposed NQR sensor is quite sufficient for successfully observation of the resonance line at the SNR equal to 9.1 ​dB.</span></p></div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":"110 ","pages":"Article 101700"},"PeriodicalIF":3.2,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.ssnmr.2020.101700","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38620538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Iterative baseline correction algorithm for dead time truncated one-dimensional solid-state MAS NMR spectra","authors":"Maxime Yon,&nbsp;Franck Fayon,&nbsp;Dominique Massiot,&nbsp;Vincent Sarou-Kanian","doi":"10.1016/j.ssnmr.2020.101699","DOIUrl":"10.1016/j.ssnmr.2020.101699","url":null,"abstract":"<div><p><span><span>We present an algorithm suitable for automatically correcting rolling baseline coming from time-domain truncation induced by the dead time in pulse-acquire one-dimensional MAS </span>NMR spectra<span>. It relies on an iterative estimation of the baseline restricted in the time-domain by the dead time duration combined with a histogram filter allowing adaptive selection of the baseline points. This method does not make any assumption regarding the NMR resonances line shapes or widths and does not modify the acquired free induction decay points. This makes it suitable for accurate deconvolution and quantification of single-pulse MAS NMR spectra. The baseline correction accuracy is evaluated on synthetic solid-state spectra of </span></span>¹⁹F, ⁷¹Ga, and ²³Na by comparing the fitted baseline to the theoretical one. The versatility of the algorithm is also exemplified on three additional solid-state spectra of ²³Na and ⁷¹Ga. The algorithm is made available to the community through a user-friendly standalone Matlab® application.</p></div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":"110 ","pages":"Article 101699"},"PeriodicalIF":3.2,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.ssnmr.2020.101699","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38601561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}