共查询到20条相似文献,搜索用时 15 毫秒
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Xinyi. Cai Dr. Alessandra Lucini Paioni Agnes Adler Ru Yao Wenxiao Zhang David Beriashvili Adil Safeer Andrei Gurinov Prof. Antal Rockenbauer Prof. Dr. Yuguang Song Prof. Dr. Marc Baldus Prof. Dr. Yangping Liu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(50):12758-12762
Dynamic nuclear polarization (DNP) is a powerful method to enhance the sensitivity of solid-state magnetic nuclear resonance (ssNMR) spectroscopy. However, its biomolecular applications at high magnetic fields (preferably>14 T) have so far been limited by the intrinsically low efficiency of polarizing agents and sample preparation aspects. Herein, we report a new class of trityl-nitroxide biradicals, dubbed SNAPols that combine high DNP efficiency with greatly enhanced hydrophilicity. SNAPol-1, the best compound in the series, shows DNP enhancement factors at 18.8 T of more than 100 in small molecules and globular proteins and also exhibits strong DNP enhancements in membrane proteins and cellular preparations. By integrating optimal sensitivity and high resolution, we expect widespread applications of this new polarizing agent in high-field DNP/ssNMR spectroscopy, especially for complex biomolecules. 相似文献
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Dr. Maria Concistré Dr. Subhradip Paul Marina Carravetta Ilya Kuprov Dr. Philip T. F. Williamson 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(68):15852-15854
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 14N 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. 相似文献
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Selective Protein Hyperpolarization in Cell Lysates Using Targeted Dynamic Nuclear Polarization 下载免费PDF全文
Thibault Viennet Dr. Aldino Viegas Arne Kuepper Sabine Arens Prof. Dr. Vladimir Gelev Prof. Dr. Ognyan Petrov Prof. Dr. Tom N. Grossmann Prof. Dr. Henrike Heise Dr. Manuel Etzkorn 《Angewandte Chemie (International ed. in English)》2016,55(36):10746-10750
Nuclear magnetic resonance (NMR) spectroscopy has the intrinsic capabilities to investigate proteins in native environments. In general, however, NMR relies on non‐natural protein purity and concentration to increase the desired signal over the background. We here report on the efficient and specific hyperpolarization of low amounts of a target protein in a large isotope‐labeled background by combining dynamic nuclear polarization (DNP) and the selectivity of protein interactions. Using a biradical‐labeled ligand, we were able to direct the hyperpolarization to the protein of interest, maintaining comparable signal enhancement with about 400‐fold less radicals than conventionally used. We could selectively filter out our target protein directly from crude cell lysate obtained from only 8 mL of fully isotope‐enriched cell culture. Our approach offers effective means to study proteins with atomic resolution in increasingly native concentrations and environments. 相似文献
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Yoh Matsuki Dr. Thorsten Maly Dr. Olivier Ouari Dr. Hakim Karoui Dr. François Le Moigne Dr. Egon Rizzato Dr. Sevdalina Lyubenova Dr. Judith Herzfeld Prof. Thomas Prisner Prof. Paul Tordo Prof. Robert G. Griffin Prof. 《Angewandte Chemie (International ed. in English)》2009,48(27):4996-5000
A new polarizing agent with superior performance in dynamic nuclear polarization experiments is introduced, and utilizes two TEMPO (2,2,6,6‐tetramethylpiperidine‐1‐oxyl) moieties connected through a rigid spiro tether (see structure). The observed NMR signal intensities were enhanced by a factor of 1.4 compared to those of TOTAPOL, a previously described TEMPO‐based biradical with a flexible tether.
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Pascal Miéville Puneet Ahuja Riddhiman Sarkar Dr. Sami Jannin Dr. Paul R. Vasos Dr. Sandrine Gerber‐Lemaire Dr. Mor Mishkovsky Dr. Arnaud Comment Dr. Rolf Gruetter Prof. Olivier Ouari Dr. Paul Tordo Prof. Geoffrey Bodenhausen Prof. 《Angewandte Chemie (International ed. in English)》2010,49(35):6182-6185
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In this work, we review the hyperpolarization technique named chemically induced dynamic nuclear polarization (CIDNP), focusing on the time-resolved variant of this method and its biological applications. We introduce the main principles of polarization formation in liquids at high magnetic fields, provided by the so-called spin sorting mechanism. Applications of CIDNP to studying fast reactions of short-lived free radicals of biologically important molecules are discussed, as well as the potential of the method to probe the structure and magnetic parameters of such radicals. We also explain the principles of protein CIDNP and discuss applications of time-resolved CIDNP to studies of protein structure and dynamics. 相似文献
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Adam N. Smith Dr. Marc A. Caporini Prof. Gail E. Fanucci Prof. Joanna R. Long 《Angewandte Chemie (International ed. in English)》2015,54(5):1542-1546
Dynamic nuclear polarization (DNP) magic‐angle spinning (MAS) solid‐state NMR (ssNMR) spectroscopy has the potential to enhance NMR signals by orders of magnitude and to enable NMR characterization of proteins which are inherently dilute, such as membrane proteins. In this work spin‐labeled lipid molecules (SL‐lipids), when used as polarizing agents, lead to large and relatively homogeneous DNP enhancements throughout the lipid bilayer and to an embedded lung surfactant mimetic peptide, KL4. Specifically, DNP MAS ssNMR experiments at 600 MHz/395 GHz on KL4 reconstituted in liposomes containing SL‐lipids reveal DNP enhancement values over two times larger for KL4 compared to liposome suspensions containing the biradical TOTAPOL. These findings suggest an alternative sample preparation strategy for DNP MAS ssNMR studies of lipid membranes and integral membrane proteins. 相似文献
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Pascal Miéville Puneet Ahuja Dr. Riddhiman Sarkar Dr. Sami Jannin Dr. Paul R. Vasos Dr. Sandrine Gerber‐Lemaire Dr. Mor Mishkovsky Dr. Arnaud Comment Prof. Rolf Gruetter Dr. Olivier Ouari Prof. Paul Tordo Prof. Geoffrey Bodenhausen 《Angewandte Chemie (International ed. in English)》2010,49(43):7834-7834
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Emmanuelle M. M. Weber Dr. Giuseppe Sicoli Dr. Hervé Vezin Ghislaine Frébourg Dr. Daniel Abergel Prof. Geoffrey Bodenhausen Dr. Dennis Kurzbach 《Angewandte Chemie (International ed. in English)》2018,57(18):5171-5175
Mixtures of water and glycerol provide popular matrices for low‐temperature spectroscopy of vitrified samples. However, they involve counterintuitive physicochemical properties, such as spontaneous nanoscopic phase separations (NPS) in solutions that appear macroscopically homogeneous. We demonstrate that such phenomena can substantially influence the efficiency of dynamic nuclear polarization (DNP) by factors up to 20 % by causing fluctuations in local concentrations of polarization agents (radicals). Thus, a spontaneous NPS of water/glycerol mixtures that takes place on time scales on the order of 30–60 min results in a confinement of polarization agents in nanoscopic water‐rich vesicles, which in return affects the DNP. Such effects were found for three common polarization agents, TEMPOL, AMUPol and Trityl. 相似文献
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Dynamic Nuclear Polarization Provides New Insights into Chromophore Structure in Phytochrome Photoreceptors 下载免费PDF全文
Daniel Stöppler Dr. Chen Song Dr. Barth‐Jan van Rossum Michel‐Andreas Geiger Christina Lang Prof. Dr. Maria‐Andrea Mroginski Dr. Anil Pandurang Jagtap Prof. Dr. Snorri Th. Sigurdsson Prof. Dr. Jörg Matysik Prof. Dr. Jon Hughes Prof. Dr. Hartmut Oschkinat 《Angewandte Chemie (International ed. in English)》2016,55(52):16017-16020
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Björn C. Dollmann Dr. Andrei L. Kleschyov Dr. Vasily Sen Dr. Valery Golubev Prof. Dr. Laura M. Schreiber Prof. Dr. Hans W. Spiess Dr. Kerstin Münnemann Dr. Dariush Hinderberger 《Chemphyschem》2010,11(17):3656-3663
A potentially biocompatible class of spin‐labeled macromolecules, spin‐labeled (SL) heparins, and their use as nuclear magnetic resonance (NMR) signal enhancers are introduced. The signal enhancement is achieved through Overhauser‐type dynamic nuclear polarization (DNP). All presented SL‐heparins show high 1H DNP enhancement factors up to E=?110, which validates that effectively more than one hyperfine line can be saturated even for spin‐labeled polarizing agents. The parameters for the Overhauser‐type DNP are determined and discussed. A striking result is that for spin‐labeled heparins, the off‐resonant electron paramagnetic resonance (EPR) hyperfine lines contribute a non‐negligible part to the total saturation, even in the absence of Heisenberg spin exchange (HSE) and electron spin‐nuclear spin relaxation (T1ne). As a result, we conclude that one can optimize the use of, for example, biomacromolecules for DNP, for which only small sample amounts are available, by using heterogeneously distributed radicals attached to the molecule. 相似文献
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Implementation and Characterization of Flow Injection in Dissolution Dynamic Nuclear Polarization NMR Spectroscopy 下载免费PDF全文
The use of dissolution dynamic nuclear polarization (D ‐DNP) offers substantially increased signals in liquid‐state NMR spectroscopy. A challenge in realizing this potential lies in the transfer of the hyperpolarized sample to the NMR detector without loss of hyperpolarization. Here, the use of a flow injection method using high‐pressure liquid leads to improved performance compared to the more common gas‐driven injection, by suppressing residual fluid motions during the NMR experiment while still achieving a short injection time. Apparent diffusion coefficients are determined from pulsed field gradient echo measurements, and are shown to fall below 1.5 times the value of a static sample within 0.8 s. Due to the single‐scan nature of D ‐DNP, pulsed field gradients are often the only choice for coherence selection or encoding, but their application requires stationary fluid. Sample delivery driven by a high‐pressure liquid will improve the applicability of these types of D‐DNP advanced experiments. 相似文献
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Alexandre Zagdoun Dr. Aaron J. Rossini Dr. Matthew P. Conley Wolfram R. Grüning Martin Schwarzwälder Dr. Moreno Lelli Dr. W. Trent Franks Prof. Dr. Hartmut Oschkinat Prof. Dr. Christophe Copéret Prof. Dr. Lyndon Emsley Dr. Anne Lesage 《Angewandte Chemie (International ed. in English)》2013,52(4):1222-1225
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Martin Brodrecht Kevin Herr Sarah Bothe Dr. Marcos de Oliveira Jr. Dr. Torsten Gutmann Prof. Dr. Gerd Buntkowsky 《Chemphyschem》2019,20(11):1475-1487
Specific spin labeling allows the site-selective investigation of biomolecules by EPR and DNP enhanced NMR spectroscopy. A novel spin labeling strategy for commercially available Fmoc-amino acids is developed. In this approach, the PROXYL spin label is covalently attached to the hydroxyl side chain of three amino acids hydroxyproline (Hyp), serine (Ser) and tyrosine (Tyr) by a simple three-step synthesis route. The obtained PROXYL containing building-blocks are N-terminally protected by the Fmoc-protection group, which makes them applicable for the use in solid-phase peptide synthesis (SPPS). This approach allows the insertion of the spin label at any desired position during SPPS, which makes it more versatile than the widely used post synthetic spin labeling strategies. For the final building-blocks, the radical activity is proven by EPR. DNP enhanced solid-state NMR experiments employing these building-blocks in a TCE solution show enhancement factors of up to 26 for 1H and 13C (1H→13C cross-polarization). To proof the viability of the presented building-blocks for insertion of the spin label during SPPS the penta-peptide Acetyl-Gly-Ser(PROXYL)-Gly-Gly-Gly was synthesized employing the spin labeled Ser building-block. This peptide could successfully be isolated and the spin label activity proved by EPR and DNP NMR measurements, showing enhancement factors of 12.1±0.1 for 1H and 13.9±0.5 for 13C (direct polarization). 相似文献