Magnetic resonance (Gottingen, Germany)最新文献

{"title":"Residual dipolar line width in magic-angle spinning proton solid-state NMR.","authors":"Matías Chávez, Thomas Wiegand, Alexander A Malär, Beat H Meier, Matthias Ernst","doi":"10.5194/mr-2-499-2021","DOIUrl":"10.5194/mr-2-499-2021","url":null,"abstract":"<p><p>Magic-angle spinning is routinely used to average anisotropic interactions in solid-state nuclear magnetic resonance (NMR). Due to the fact that the homonuclear dipolar Hamiltonian of a strongly coupled spin system does not commute with itself at different time points during the rotation, second-order and higher-order terms lead to a residual dipolar line broadening in the observed resonances. Additional truncation of the residual broadening due to isotropic chemical-shift differences can be observed. We analyze the residual line broadening in coupled proton spin systems based on theoretical calculations of effective Hamiltonians up to third order using Floquet theory and compare these results to numerically obtained effective Hamiltonians in small spin systems. We show that at spinning frequencies beyond 75 kHz, second-order terms dominate the residual line width, leading to a <math><mrow><mn>1</mn><mo>/</mo><msub><mi>ω</mi><mi>r</mi></msub></mrow></math> dependence of the second moment which we use to characterize the line width. However, chemical-shift truncation leads to a partial <math><mrow><msubsup><mi>ω</mi><mi>r</mi><mrow><mo>-</mo><mn>2</mn></mrow></msubsup></mrow></math> dependence of the line width which looks as if third-order effective Hamiltonian terms are contributing significantly. At slower spinning frequencies, cross terms between the chemical shift and the dipolar coupling can contribute in third-order effective Hamiltonians. We show that second-order contributions not only broaden the line, but also lead to a shift of the center of gravity of the line. Experimental data reveal such spinning-frequency-dependent line shifts in proton spectra in model substances that can be explained by line shifts induced by the second-order dipolar Hamiltonian.</p>","PeriodicalId":93333,"journal":{"name":"Magnetic resonance (Gottingen, Germany)","volume":" ","pages":"499-509"},"PeriodicalIF":0.0,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10539731/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47788818","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":"Exclusively heteronuclear NMR experiments for the investigation of intrinsically disordered proteins: focusing on proline residues.","authors":"Isabella C Felli,&nbsp;Wolfgang Bermel,&nbsp;Roberta Pierattelli","doi":"10.5194/mr-2-511-2021","DOIUrl":"10.5194/mr-2-511-2021","url":null,"abstract":"<p><p>NMR represents a key spectroscopic technique that contributes to the emerging field of highly flexible, intrinsically disordered proteins (IDPs) or protein regions (IDRs) that lack a stable three-dimensional structure. A set of exclusively heteronuclear NMR experiments tailored for proline residues, highly abundant in IDPs/IDRs, are presented here. They provide a valuable complement to the widely used approach based on amide proton detection, filling the gap introduced by the lack of amide protons in proline residues within polypeptide chains. The novel experiments have very interesting properties for the investigations of IDPs/IDRs of increasing complexity.</p>","PeriodicalId":93333,"journal":{"name":"Magnetic resonance (Gottingen, Germany)","volume":" ","pages":"511-522"},"PeriodicalIF":0.0,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10539766/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42223623","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":"Supplementary material to \"Anomalous Amide Proton Chemical Shifts as Signatures of Hydrogen Bonding to Aromatic Sidechains\"","authors":"Kumaran Baskaran, Colin W. Wilburn, Jonathan R. Wedell, Leonardus M. I. Koharudin, E. Ulrich, A. Schuyler, H. Eghbalnia, A. Gronenborn, J. Hoch","doi":"10.5194/MR-2021-53","DOIUrl":"https://doi.org/10.5194/MR-2021-53","url":null,"abstract":"Abstract. Hydrogen bonding between an amide group and the p-π cloud of an aromatic ring was first identified in a protein in the 1980s. Subsequent surveys of high-resolution X-ray crystal structures found multiple instances, but their preponderance was determined to be infrequent. Hydrogen atoms participating in a hydrogen bond to the p-π cloud of an aromatic ring are expected to experience an upfield chemical shift arising from a shielding ring current shift. We survey the Biological Magnetic Resonance Data Bank for amide hydrogens exhibiting unusual shifts as well as corroborating nuclear Overhauser effects between the amide protons and ring protons. We find evidence that Trp residues are more likely to be involved in p-π hydrogen bonds than other aromatic amino acids, whereas His residues are more likely to be involved in hydrogen bonds with a ring nitrogen acting as the hydrogen acceptor. The p-π hydrogen bonds may be more abundant than previously believed. The inclusion in NMR structure refinement protocols of shift effects in amide protons from aromatic side chains, or explicit hydrogen bond restraints between amides and aromatic rings, could improve the local accuracy of side-chain orientations in solution NMR protein structures, but their impact on global accuracy is likely be limited.\u0000","PeriodicalId":93333,"journal":{"name":"Magnetic resonance (Gottingen, Germany)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43284747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of radial radio-frequency field inhomogeneity on MAS solid-state NMR experiments.","authors":"Kathrin Aebischer, Zdeněk Tošner, Matthias Ernst","doi":"10.5194/mr-2-523-2021","DOIUrl":"10.5194/mr-2-523-2021","url":null,"abstract":"<p><p>Radio-frequency field inhomogeneity is one of the most common imperfections in NMR experiments. They can lead to imperfect flip angles of applied radio-frequency (rf) pulses or to a mismatch of resonance conditions, resulting in artefacts or degraded performance of experiments. In solid-state NMR under magic angle spinning (MAS), the radial component becomes time-dependent because the rf irradiation amplitude and phase is modulated with integer multiples of the spinning frequency. We analyse the influence of such time-dependent MAS-modulated rf fields on the performance of some commonly used building blocks of solid-state NMR experiments. This analysis is based on analytical Floquet calculations and numerical simulations, taking into account the time dependence of the rf field. We find that, compared to the static part of the rf field inhomogeneity, such time-dependent modulations play a very minor role in the performance degradation of the investigated typical solid-state NMR experiments.</p>","PeriodicalId":93333,"journal":{"name":"Magnetic resonance (Gottingen, Germany)","volume":" ","pages":"523-543"},"PeriodicalIF":0.0,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10539735/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42766236","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":"Nuclear magnetic resonance free ligand conformations and atomic resolution dynamics.","authors":"Amber Y S Balazs, Nichola L Davies, David Longmire, Martin J Packer, Elisabetta Chiarparin","doi":"10.5194/mr-2-489-2021","DOIUrl":"10.5194/mr-2-489-2021","url":null,"abstract":"<p><p>Knowledge of free ligand conformational preferences (energy minima) and conformational dynamics (rotational energy barriers) of small molecules in solution can guide drug design hypotheses and help rank ideas to bias syntheses towards more active compounds. Visualization of conformational exchange dynamics around torsion angles, by replica exchange with solute tempering molecular dynamics (REST-MD), gives results in agreement with high-resolution <math><msup><mi></mi><mn>1</mn></msup></math>H nuclear magnetic resonance (NMR) spectra and complements free ligand conformational analyses. Rotational energy barriers around individual bonds are comparable between calculated and experimental values, making the in-silico method relevant to ranking prospective design ideas in drug discovery programs, particularly across a series of analogs. Prioritizing design ideas, based on calculations and analysis of measurements across a series, efficiently guides rational discovery towards the \"right molecules\" for effective medicines.</p>","PeriodicalId":93333,"journal":{"name":"Magnetic resonance (Gottingen, Germany)","volume":"2 1","pages":"489-498"},"PeriodicalIF":0.0,"publicationDate":"2021-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10539760/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71415880","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":"Signal-to-noise ratio in diffusion-ordered spectroscopy: how good is good enough?","authors":"Jamie Guest, P. Kiraly, M. Nilsson, G. Morris","doi":"10.5194/mr-2021-52","DOIUrl":"https://doi.org/10.5194/mr-2021-52","url":null,"abstract":"Abstract. Diffusion-ordered NMR spectroscopy (DOSY) constructs multidimensional spectra displaying signal strength as a function of Larmor frequency and of diffusion coefficient from experimental measurements using pulsed field gradient spin or stimulated echoes. Peak positions in the diffusion domain are determined by diffusion coefficients estimated by fitting experimental data to some variant of the Stejskal-Tanner equation, with the peak widths determined by the standard error estimated in the fitting process. The accuracy and reliability of the diffusion domain in DOSY spectra are therefore determined by the uncertainties in the experimental data, and thus in part by the signal-to-noise ratio of the experimental spectra measured. Here the Cramér-Rao lower bound, Monte Carlo methods and experimental data are used to investigate the relationship between signal-to-noise ratio, experimental parameters, and diffusion domain accuracy in 2D DOSY experiments. Experimental results confirm that sources of error other than noise put an upper limit on the improvement in diffusion domain accuracy obtainable by time averaging.\u0000","PeriodicalId":93333,"journal":{"name":"Magnetic resonance (Gottingen, Germany)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41621861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improved NMR transfer of magnetization from protons to half-integer spin quadrupolar nuclei at moderate and high magic-angle spinning frequencies.","authors":"Jennifer S Gómez, Andrew G M Rankin, Julien Trébosc, Frédérique Pourpoint, Yu Tsutsumi, Hiroki Nagashima, Olivier Lafon, Jean-Paul Amoureux","doi":"10.5194/mr-2-447-2021","DOIUrl":"10.5194/mr-2-447-2021","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Half-integer spin quadrupolar nuclei are the only magnetic isotopes for the majority of the chemical elements. Therefore, the transfer of polarization from protons to these isotopes under magic-angle spinning (MAS) can provide precious insights into the interatomic proximities in hydrogen-containing solids, including organic, hybrid, nanostructured and biological solids. This transfer has recently been combined with dynamic nuclear polarization (DNP) in order to enhance the NMR signal of half-integer quadrupolar isotopes. However, the cross-polarization transfer lacks robustness in the case of quadrupolar nuclei, and we have recently introduced as an alternative technique a &lt;math&gt;&lt;mi&gt;D&lt;/mi&gt;&lt;/math&gt;-RINEPT (through-space refocused insensitive nuclei enhancement by polarization transfer) scheme combining a heteronuclear dipolar recoupling built from adiabatic pulses and a continuous-wave decoupling. This technique has been demonstrated at 9.4 T with moderate MAS frequencies, &lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;ν&lt;/mi&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;/msub&gt;&lt;mo&gt;≈&lt;/mo&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;-15 kHz, in order to transfer the DNP-enhanced &lt;math&gt;&lt;msup&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/msup&gt;&lt;/math&gt;H polarization to quadrupolar nuclei. Nevertheless, polarization transfers from protons to quadrupolar nuclei are also required at higher MAS frequencies in order to improve the &lt;math&gt;&lt;msup&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/msup&gt;&lt;/math&gt;H resolution. We investigate here how this transfer can be achieved at &lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;ν&lt;/mi&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;/msub&gt;&lt;mo&gt;≈&lt;/mo&gt;&lt;mn&gt;20&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt; and 60 kHz. We demonstrate that the &lt;math&gt;&lt;mi&gt;D&lt;/mi&gt;&lt;/math&gt;-RINEPT sequence using adiabatic pulses still produces efficient and robust transfers but requires large radio-frequency (rf) fields, which may not be compatible with the specifications of most MAS probes. As an alternative, we introduce robust and efficient variants of the &lt;math&gt;&lt;mi&gt;D&lt;/mi&gt;&lt;/math&gt;-RINEPT and PRESTO (phase-shifted recoupling effects a smooth transfer of order) sequences using symmetry-based recoupling schemes built from single and composite &lt;math&gt;&lt;mi&gt;π&lt;/mi&gt;&lt;/math&gt; pulses. Their performances are compared using the average Hamiltonian theory and experiments at &lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;B&lt;/mi&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/msub&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;18.8&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt; T on &lt;math&gt;&lt;mi&gt;γ&lt;/mi&gt;&lt;/math&gt;-alumina and isopropylamine-templated microporous aluminophosphate (AlPO&lt;math&gt;&lt;msub&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/msub&gt;&lt;/math&gt;-14), featuring low and significant &lt;math&gt;&lt;msup&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/msup&gt;&lt;/math&gt;H-&lt;math&gt;&lt;msup&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/msup&gt;&lt;/math&gt;H dipolar interactions, respectively. These experiments demonstrate that the &lt;math&gt;&lt;msup&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/msup&gt;&lt;/math&gt;H magnetization can be efficiently transferred to &lt;math&gt;&lt;msup&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;27&lt;/mn&gt;&lt;/msup&gt;&lt;/math&gt;Al nuclei using &lt;math&gt;&lt;mi&gt;D&lt;/mi&gt;&lt;/math&gt;-RINEPT with &lt;math&gt;&lt;mrow&gt;&lt;mi&gt;SR&lt;/mi&gt;&lt;msubsup&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msubsup&gt;&lt;/mrow&gt;&lt;/math&gt;(270&lt;math&gt;&lt;msub&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/msub&gt;&lt;/math&gt;90&lt;math&gt;&lt;msub&gt;&lt;mi&gt;&lt;/mi&gt;&lt;mn&gt;180&lt;/mn&gt;&lt;/msub&gt;&lt;/math&gt;) recoupli","PeriodicalId":93333,"journal":{"name":"Magnetic resonance (Gottingen, Germany)","volume":"2 1","pages":"447-464"},"PeriodicalIF":0.0,"publicationDate":"2021-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10539806/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71415877","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":"Introduction to a special issue of <i>Magnetic Resonance</i> in honour of Robert Kaptein at the occasion of his 80th birthday.","authors":"Rolf Boelens,&nbsp;Konstantin Ivanov,&nbsp;Jörg Matysik","doi":"10.5194/mr-2-465-2021","DOIUrl":"10.5194/mr-2-465-2021","url":null,"abstract":"<p><p>This publication, in honour of Robert Kaptein's 80th birthday, contains contributions from colleagues, many of whom have worked with him, and others who admire his work and have been stimulated by his research. The contributions show current research in biomolecular NMR, spin hyperpolarisation and spin chemistry, including CIDNP (chemically induced dynamic nuclear polarisation), topics to which he has contributed enormously. His proposal of the radical pair mechanism was the birth of the field of spin chemistry, and the laser CIDNP NMR experiment on a protein was a major breakthrough in hyperpolarisation research. He set milestones for biomolecular NMR by developing computational methods for protein structure determination, including restrained molecular dynamics and 3D NMR methodology. With a lac repressor headpiece, he determined one of the first protein structures determined by NMR. His studies of the lac repressor provided the first examples of detailed studies of protein nucleic acid complexes by NMR. This deepened our understanding of protein DNA recognition and led to a molecular model for protein sliding along the DNA. Furthermore, he played a leading role in establishing the cluster of NMR large-scale facilities in Europe. This editorial gives an introduction to the publication and is followed by a biography describing his contributions to magnetic resonance.</p>","PeriodicalId":93333,"journal":{"name":"Magnetic resonance (Gottingen, Germany)","volume":"2 1","pages":"465-474"},"PeriodicalIF":0.0,"publicationDate":"2021-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10539797/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71415878","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":"Extended Bloch-McConnell equations for mechanistic analysis of hyperpolarized ¹³C magnetic resonance experiments on enzyme systems.","authors":"Thomas R Eykyn, Stuart J Elliott, Philip W Kuchel","doi":"10.5194/mr-2-421-2021","DOIUrl":"10.5194/mr-2-421-2021","url":null,"abstract":"<p><p>We describe an approach to formulating the kinetic master equations of the time evolution of NMR signals in reacting (bio)chemical systems. Special focus is given to studies that employ signal enhancement (hyperpolarization) methods such as dissolution dynamic nuclear polarization (dDNP) and involving nuclear spin-bearing solutes that undergo reactions mediated by enzymes and membrane transport proteins. We extend the work given in a recent presentation on this topic (Kuchel and Shishmarev, 2020) to now include enzymes with two or more substrates and various enzyme reaction mechanisms as classified by Cleland, with particular reference to non-first-order processes. Using this approach, we can address some pressing questions in the field from a theoretical standpoint. For example, why does binding of a hyperpolarized substrate to an enzyme <i>not</i> cause an appreciable loss of the signal from the substrate or product? Why does the concentration of an unlabelled pool of substrate, for example <math><msup><mi></mi><mn>12</mn></msup></math>C lactate, cause an increase in the rate of exchange of the <math><msup><mi></mi><mn>13</mn></msup></math>C-labelled pool? To what extent is the equilibrium position of the reaction perturbed during administration of the substrate? The formalism gives a full mechanistic understanding of the time courses derived and is of relevance to ongoing clinical trials using these techniques.</p>","PeriodicalId":93333,"journal":{"name":"Magnetic resonance (Gottingen, Germany)","volume":"2 1","pages":"421-446"},"PeriodicalIF":0.0,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10539799/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71415874","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":"¹²⁹Xe ultra-fast Z spectroscopy enables micromolar detection of biosensors on a 1 T benchtop spectrometer.","authors":"Kévin Chighine,&nbsp;Estelle Léonce,&nbsp;Céline Boutin,&nbsp;Hervé Desvaux,&nbsp;Patrick Berthault","doi":"10.5194/mr-2-409-2021","DOIUrl":"10.5194/mr-2-409-2021","url":null,"abstract":"<p><p>The availability of a benchtop nuclear magnetic resonance (NMR) spectrometer, of low cost and easily transportable, can allow detection of low quantities of biosensors, provided that hyperpolarized species are used. Here we show that the micromolar threshold can easily be reached by employing laser-polarized xenon and cage molecules reversibly hosting it. Indirect detection of caged xenon is made via chemical exchange, using ultra-fast Z spectroscopy based on spatio-temporal encoding. On this non-dedicated low-field spectrometer, several ideas are proposed to improve the signal.</p>","PeriodicalId":93333,"journal":{"name":"Magnetic resonance (Gottingen, Germany)","volume":"2 1","pages":"409-420"},"PeriodicalIF":0.0,"publicationDate":"2021-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10539730/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71415867","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}