Magnetic resonance (Gottingen, Germany)最新文献

{"title":"Facilitating the structural characterisation of non-canonical amino acids in biomolecular NMR.","authors":"Sarah Kuschert, Martin Stroet, Yanni Ka-Yan Chin, Anne Claire Conibear, Xinying Jia, Thomas Lee, Christian Reinhard Otto Bartling, Kristian Strømgaard, Peter Güntert, Karl Johan Rosengren, Alan Edward Mark, Mehdi Mobli","doi":"10.5194/mr-4-57-2023","DOIUrl":"10.5194/mr-4-57-2023","url":null,"abstract":"<p><p>Peptides and proteins containing non-canonical amino acids (ncAAs) are a large and important class of biopolymers. They include non-ribosomally synthesised peptides, post-translationally modified proteins, expressed or synthesised proteins containing unnatural amino acids, and peptides and proteins that are chemically modified. Here, we describe a general procedure for generating atomic descriptions required to incorporate ncAAs within popular NMR structure determination software such as CYANA, CNS, Xplor-NIH and ARIA. This procedure is made publicly available via the existing Automated Topology Builder (ATB) server (https://atb.uq.edu.au, last access: 17 February 2023) with all submitted ncAAs stored in a dedicated database. The described procedure also includes a general method for linking of side chains of amino acids from CYANA templates. To ensure compatibility with other systems, atom names comply with IUPAC guidelines. In addition to describing the workflow, 3D models of complex natural products generated by CYANA are presented, including vancomycin. In order to demonstrate the manner in which the templates for ncAAs generated by the ATB can be used in practice, we use a combination of CYANA and CNS to solve the structure of a synthetic peptide designed to disrupt Alzheimer-related protein-protein interactions. Automating the generation of structural templates for ncAAs will extend the utility of NMR spectroscopy to studies of more complex biomolecules, with applications in the rapidly growing fields of synthetic biology and chemical biology. The procedures we outline can also be used to standardise the creation of structural templates for any amino acid and thus have the potential to impact structural biology more generally.</p>","PeriodicalId":93333,"journal":{"name":"Magnetic resonance (Gottingen, Germany)","volume":" ","pages":"57-72"},"PeriodicalIF":0.0,"publicationDate":"2023-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10583272/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45931004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Paramagnetic relaxivity of delocalized long-lived states of protons in chains of CH₂ groups.","authors":"Aiky Razanahoera, Anna Sonnefeld, Geoffrey Bodenhausen, Kirill Sheberstov","doi":"10.5194/mr-4-47-2023","DOIUrl":"10.5194/mr-4-47-2023","url":null,"abstract":"<p><p>Long-lived states (LLSs) have lifetimes <math><mrow><msub><mi>T</mi><mi>LLS</mi></msub></mrow></math> that can be much longer than longitudinal relaxation times <math><mrow><msub><mi>T</mi><mn>1</mn></msub></mrow></math>. In molecules containing several geminal pairs of protons in neighboring CH<math><msub><mi></mi><mn>2</mn></msub></math> groups, it has been shown that <i>delocalized</i> LLSs can be excited by converting magnetization into imbalances between the populations of singlet and triplet states of each pair. Since the empirical yield of the conversion and reconversion of observable magnetization into LLSs and back is on the order of 10 % if one uses spin-lock induced crossing (SLIC), it would be desirable to boost the sensitivity by dissolution dynamic nuclear polarization (d-DNP). To enhance the magnetization of nuclear spins by d-DNP, the analytes must be mixed with radicals such as 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPOL). After dissolution, these radicals lead to an undesirable paramagnetic relaxation enhancement (PRE) which shortens not only the longitudinal relaxation times <math><mrow><msub><mi>T</mi><mn>1</mn></msub></mrow></math> but also the lifetimes <math><mrow><msub><mi>T</mi><mi>LLS</mi></msub></mrow></math> of LLSs. It is shown in this work that PRE by TEMPOL is less deleterious for LLSs than for longitudinal magnetization for four different molecules: 2,2-dimethyl-2-silapentane-5-sulfonate (DSS), homotaurine, taurine, and acetylcholine. The relaxivities <math><mrow><msub><mi>r</mi><mi>LLS</mi></msub></mrow></math> (i.e., the slopes of the relaxation rate constants <math><mrow><msub><mi>R</mi><mi>LLS</mi></msub></mrow></math> as a function of the radical concentration) are 3 to 5 times smaller than the relaxivities <math><mrow><msub><mi>r</mi><mn>1</mn></msub></mrow></math> of longitudinal magnetization. Partial delocalization of the LLSs across neighboring CH<math><msub><mi></mi><mn>2</mn></msub></math> groups may decrease this advantage, but in practice, this effect was observed to be small, for example, when comparing taurine containing two CH<math><msub><mi></mi><mn>2</mn></msub></math> groups and homotaurine with three CH<math><msub><mi></mi><mn>2</mn></msub></math> groups. Regardless of whether the LLSs are delocalized or not, it is shown that PRE should not be a major problem for experiments combining d-DNP and LLSs, provided the concentration of paramagnetic species after dissolution does not exceed 1 mM, a condition that is readily fulfilled in typical d-DNP experiments. In bullet d-DNP experiments however, it may be necessary to decrease the concentration of TEMPOL or to add ascorbate for chemical reduction.</p>","PeriodicalId":93333,"journal":{"name":"Magnetic resonance (Gottingen, Germany)","volume":" ","pages":"47-56"},"PeriodicalIF":0.0,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10583270/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48700612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of the zero-field splitting in light-induced pulsed dipolar electron paramagnetic resonance (EPR) spectroscopy.","authors":"Andreas Scherer, Berk Yildirim, Malte Drescher","doi":"10.5194/mr-4-27-2023","DOIUrl":"10.5194/mr-4-27-2023","url":null,"abstract":"<p><p>Laser-induced magnetic dipole (LaserIMD) spectroscopy and light-induced double electron-electron resonance (LiDEER) spectroscopy are important techniques in the emerging field of light-induced pulsed dipolar electron paramagnetic resonance (EPR) spectroscopy (light-induced PDS). These techniques use the photoexcitation of a chromophore to the triplet state and measure its dipolar coupling to a neighboring electron spin, which allows the determination of distance restraints. To date, LaserIMD and LiDEER have been analyzed with software tools that were developed for a pair of two <math><mrow><mi>S</mi><mo>=</mo><mn>1</mn><mo>/</mo><mn>2</mn></mrow></math> spins and that neglected the zero-field splitting (ZFS) of the excited triplet. Here, we explore the limits of this assumption and show that the ZFS can have a significant effect on the shape of the dipolar trace. For a detailed understanding of the effect of the ZFS, a theoretical description for LaserIMD and LiDEER is derived, taking into account the non-secular terms of the ZFS. Simulations based on this model show that the effect of the ZFS is not that pronounced in LiDEER for experimentally relevant conditions. However, the ZFS leads to an additional decay in the dipolar trace in LaserIMD. This decay is not that pronounced in Q-band but can be quite noticeable for lower magnetic field strengths in X-band. Experimentally recorded LiDEER and LaserIMD data confirm these findings. It is shown that ignoring the ZFS in the data analysis of LaserIMD traces can lead to errors in the obtained modulation depths and background decays. In X-band, it is additionally possible that the obtained distance distribution is plagued by long distance artifacts.</p>","PeriodicalId":93333,"journal":{"name":"Magnetic resonance (Gottingen, Germany)","volume":" ","pages":"27-46"},"PeriodicalIF":0.0,"publicationDate":"2023-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10583298/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48817966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intermolecular contributions, filtration effects and signal composition of SIFTER (single-frequency technique for refocusing).","authors":"Agathe Vanas, Janne Soetbeer, Frauke Diana Breitgoff, Henrik Hintz, Muhammad Sajid, Yevhen Polyhach, Adelheid Godt, Gunnar Jeschke, Maxim Yulikov, Daniel Klose","doi":"10.5194/mr-4-1-2023","DOIUrl":"10.5194/mr-4-1-2023","url":null,"abstract":"<p><p>To characterize structure and molecular order in the nanometre range, distances between electron spins and their distributions can be measured via dipolar spin-spin interactions by different pulsed electron paramagnetic resonance experiments. Here, for the single-frequency technique for refocusing dipolar couplings (SIFTER), the buildup of dipolar modulation signal and intermolecular contributions is analysed for a uniform random distribution of monoradicals and biradicals in frozen glassy solvent by using the product operator formalism for electron spin <math><mrow><mi>S</mi><mo>=</mo><mn>1</mn><mo>/</mo><mn>2</mn></mrow></math>. A dipolar oscillation artefact appearing at both ends of the SIFTER time trace is predicted, which originates from the weak coherence transfer between biradicals. The relative intensity of this artefact is predicted to be temperature independent but to increase with the spin concentration in the sample. Different compositions of the intermolecular background are predicted in the case of biradicals and in the case of monoradicals. Our theoretical account suggests that the appropriate procedure of extracting the intramolecular dipolar contribution (form factor) requires fitting and subtracting the unmodulated part, followed by division by an intermolecular background function that is different in shape. This scheme differs from the previously used heuristic background division approach. We compare our theoretical derivations to experimental SIFTER traces for nitroxide and trityl monoradicals and biradicals. Our analysis demonstrates a good qualitative match with the proposed theoretical description. The resulting perspectives for a quantitative analysis of SIFTER data are discussed.</p>","PeriodicalId":93333,"journal":{"name":"Magnetic resonance (Gottingen, Germany)","volume":" ","pages":"1-18"},"PeriodicalIF":0.0,"publicationDate":"2023-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10807728/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42577409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanical ordering of pigment crystallites in oil binder: can electron paramagnetic resonance reveal the gesture of an artist?","authors":"Elise Garel,&nbsp;Laurent Binet,&nbsp;Didier Gourier","doi":"10.5194/mr-3-211-2022","DOIUrl":"10.5194/mr-3-211-2022","url":null,"abstract":"<p><p>Is it possible to reconstruct the gesture of an ancient artist applying a paint layer, considering that the orientation distribution of crystallites of an inorganic pigment remains definitively imprinted on the support after drying of the layer? If the pigment contains paramagnetic transition metal ions whose magnetic interactions are themselves anisotropic, then the shape of the electron paramagnetic resonance (EPR) spectrum should reflect the distribution of grain orientations. We have demonstrated this effect in the case of Egyptian blue CaCuSi<math><msub><mi></mi><mn>4</mn></msub></math>O<math><msub><mi></mi><mn>10</mn></msub></math>, a pigment used for at least 3 millennia in antiquity, by reconstructing the probability density of crystallite orientations under various modes of application, such as brush painting, dabbing and droplet deposition.</p>","PeriodicalId":93333,"journal":{"name":"Magnetic resonance (Gottingen, Germany)","volume":"1 1","pages":"211-220"},"PeriodicalIF":0.0,"publicationDate":"2022-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10539773/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42187657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electroplated waveguides to enhance DNP and EPR spectra of silicon and diamond particles.","authors":"Aaron Himmler,&nbsp;Mohammed M Albannay,&nbsp;Gevin von Witte,&nbsp;Sebastian Kozerke,&nbsp;Matthias Ernst","doi":"10.5194/mr-3-203-2022","DOIUrl":"10.5194/mr-3-203-2022","url":null,"abstract":"<p><p>Electroplating the waveguide of a 7 T polarizer in a simple innovative way increased microwave power delivered to the sample by 3.1 dB. Silicon particles, while interesting for hyperpolarized MRI applications, are challenging to polarize due to inefficient microwave multipliers at the electron Larmor frequency at high magnetic fields and fast electronic relaxation times. Improving microwave transmission directly translates to more efficient EPR excitation at high-field, low-temperature conditions and promises faster and higher <math><msup><mi></mi><mn>29</mn></msup></math>Si polarization buildup through dynamic nuclear polarization (DNP).</p>","PeriodicalId":93333,"journal":{"name":"Magnetic resonance (Gottingen, Germany)","volume":" ","pages":"203-209"},"PeriodicalIF":0.0,"publicationDate":"2022-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10539804/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47412696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fine optimization of a dissolution dynamic nuclear polarization experimental setting for ¹³C NMR of metabolic samples.","authors":"Arnab Dey, Benoît Charrier, Karine Lemaitre, Victor Ribay, Dmitry Eshchenko, Marc Schnell, Roberto Melzi, Quentin Stern, Samuel F Cousin, James G Kempf, Sami Jannin, Jean-Nicolas Dumez, Patrick Giraudeau","doi":"10.5194/mr-3-183-2022","DOIUrl":"10.5194/mr-3-183-2022","url":null,"abstract":"<p><p>NMR-based analysis of metabolite mixtures provides crucial information on biological systems but mostly relies on 1D <math><msup><mi></mi><mn>1</mn></msup></math>H experiments for maximizing sensitivity. However, strong peak overlap of <math><msup><mi></mi><mn>1</mn></msup></math>H spectra often is a limitation for the analysis of inherently complex biological mixtures. Dissolution dynamic nuclear polarization (d-DNP) improves NMR sensitivity by several orders of magnitude, which enables <math><msup><mi></mi><mn>13</mn></msup></math>C NMR-based analysis of metabolites at natural abundance. We have recently demonstrated the successful introduction of d-DNP into a full untargeted metabolomics workflow applied to the study of plant metabolism. Here we describe the systematic optimization of d-DNP experimental settings for experiments at natural <math><msup><mi></mi><mn>13</mn></msup></math>C abundance and show how the resolution, sensitivity, and ultimately the number of detectable signals improve as a result. We have systematically optimized the parameters involved (in a semi-automated prototype d-DNP system, from sample preparation to signal detection, aiming at providing an optimization guide for potential users of such a system, who may not be experts in instrumental development). The optimization procedure makes it possible to detect previously inaccessible protonated <math><msup><mi></mi><mn>13</mn></msup></math>C signals of metabolites at natural abundance with at least 4 times improved line shape and a high repeatability compared to a previously reported d-DNP-enhanced untargeted metabolomic study. This extends the application scope of hyperpolarized <math><msup><mi></mi><mn>13</mn></msup></math>C NMR at natural abundance and paves the way to a more general use of DNP-hyperpolarized NMR in metabolomics studies.</p>","PeriodicalId":93333,"journal":{"name":"Magnetic resonance (Gottingen, Germany)","volume":" ","pages":"183-202"},"PeriodicalIF":0.0,"publicationDate":"2022-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10583282/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49369557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Site-selective generation of lanthanoid binding sites on proteins using 4-fluoro-2,6-dicyanopyridine.","authors":"Sreelakshmi Mekkattu Tharayil, Mithun C Mahawaththa, Akiva Feintuch, Ansis Maleckis, Sven Ullrich, Richard Morewood, Michael J Maxwell, Thomas Huber, Christoph Nitsche, Daniella Goldfarb, Gottfried Otting","doi":"10.5194/mr-3-169-2022","DOIUrl":"10.5194/mr-3-169-2022","url":null,"abstract":"<p><p>The paramagnetism of a lanthanoid tag site-specifically installed on a protein provides a rich source of structural information accessible by nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) spectroscopy. Here we report a lanthanoid tag for selective reaction with cysteine or selenocysteine with formation of a (seleno)thioether bond and a short tether between the lanthanoid ion and the protein backbone. The tag is assembled on the protein in three steps, comprising (i) reaction with 4-fluoro-2,6-dicyanopyridine (FDCP); (ii) reaction of the cyano groups with <math><mi>α</mi></math>-cysteine, penicillamine or <math><mi>β</mi></math>-cysteine to complete the lanthanoid chelating moiety; and (iii) titration with a lanthanoid ion. FDCP reacts much faster with selenocysteine than cysteine, opening a route for selective tagging in the presence of solvent-exposed cysteine residues. Loaded with <math><mrow><msup><mi>Tb</mi><mrow><mn>3</mn><mo>+</mo></mrow></msup></mrow></math> and <math><mrow><msup><mi>Tm</mi><mrow><mn>3</mn><mo>+</mo></mrow></msup></mrow></math> ions, pseudocontact shifts were observed in protein NMR spectra, confirming that the tag delivers good immobilisation of the lanthanoid ion relative to the protein, which was also manifested in residual dipolar couplings. Completion of the tag with different 1,2-aminothiol compounds resulted in different magnetic susceptibility tensors. In addition, the tag proved suitable for measuring distance distributions in double electron-electron resonance experiments after titration with <math><mrow><msup><mi>Gd</mi><mrow><mn>3</mn><mo>+</mo></mrow></msup></mrow></math> ions.</p>","PeriodicalId":93333,"journal":{"name":"Magnetic resonance (Gottingen, Germany)","volume":" ","pages":"169-182"},"PeriodicalIF":0.0,"publicationDate":"2022-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10539774/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48383481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reverse dynamic nuclear polarisation for indirect detection of nuclear spins close to unpaired electrons.","authors":"Nino Wili, Jan Henrik Ardenkjær-Larsen, Gunnar Jeschke","doi":"10.5194/mr-3-161-2022","DOIUrl":"10.5194/mr-3-161-2022","url":null,"abstract":"<p><p>Polarisation transfer schemes and indirect detection are central to magnetic resonance. Using the trityl radical OX063 and a pulse electron paramagnetic resonance spectrometer operating in the Q-band (35 GHz, 1.2 T), we show here that it is possible to use pulsed dynamic nuclear polarisation (DNP) to transfer polarisation from electrons to protons <i>and back</i>. The latter is achieved by first saturating the electrons and then simply using a reverse DNP step. A variable mixing time between DNP and reverse DNP allows us to investigate the decay of polarisation on protons in the vicinity of the electrons. We qualitatively investigate the influence of solvent deuteration, temperature, and electron concentration. We expect reverse DNP to be useful in the investigation of nuclear spin diffusion and envisage its use in electron-nuclear double-resonance (ENDOR) experiments.</p>","PeriodicalId":93333,"journal":{"name":"Magnetic resonance (Gottingen, Germany)","volume":" ","pages":"161-168"},"PeriodicalIF":0.0,"publicationDate":"2022-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10539835/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45600491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Visualization of dynamics in coupled multi-spin systems.","authors":"Jingyan Xu,&nbsp;Dmitry Budker,&nbsp;Danila A Barskiy","doi":"10.5194/mr-3-145-2022","DOIUrl":"10.5194/mr-3-145-2022","url":null,"abstract":"<p><p>Since the dawn of quantum mechanics, ways to visualize spins and their interactions have attracted the attention of researchers and philosophers of science. In this work we present a generalized measurement-based 3D-visualization approach for describing dynamics in strongly coupled spin ensembles. The approach brings together angular momentum probability surfaces (AMPS), Husimi <math><mi>Q</mi></math> functions, and DROPS (discrete representations of operators for spin systems) and finds particular utility when the total angular momentum basis is used for describing Hamiltonians. We show that, depending on the choice of a generalized measurement operator, the plotted surfaces either represent probabilities of finding the maximal projection of an angular momentum along any direction in space or represent measurable coherences between the states with different total angular momenta. Such effects are difficult to grasp by looking at (time-dependent) numerical values of density-matrix elements. The approach is complete in a sense that there is one-to-one correspondence between the plotted surfaces and the density matrix. Three examples of nuclear spin dynamics in two-spin systems are visualized: (i) a zero- to ultralow-field (ZULF) nuclear magnetic resonance (NMR) experiment in the presence of a magnetic field applied perpendicularly to the sensitive axis of the detector, (ii) interplay between chemical exchange and spin dynamics during high-field signal amplification by reversible exchange (SABRE), and (iii) a high-field spin-lock-induced crossing (SLIC) sequence, with the initial state being the singlet state between two spins. The presented visualization technique facilitates intuitive understanding of spin dynamics during complex experiments as exemplified here by the considered cases. Temporal sequences (\"the movies\") of such surfaces show phenomena like interconversion of spin order between the coupled spins and are particularly relevant in ZULF NMR.</p>","PeriodicalId":93333,"journal":{"name":"Magnetic resonance (Gottingen, Germany)","volume":" ","pages":"145-160"},"PeriodicalIF":0.0,"publicationDate":"2022-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10583293/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43376360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}