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Towards a unified picture of polarization transfer — pulsed DNP and chemically equivalent PHIP 实现极化转移的统一图景--脉冲 DNP 和化学等效的 PHIP
IF 2.2 3区 化学 Q3 BIOCHEMICAL RESEARCH METHODS Pub Date : 2024-04-12 DOI: 10.1016/j.jmr.2024.107671
Martin C. Korzeczek , Laurynas Dagys , Christoph Müller , Benedikt Tratzmiller , Alon Salhov , Tim Eichhorn , Jochen Scheuer , Stephan Knecht , Martin B. Plenio , Ilai Schwartz

Nuclear spin hyperpolarization techniques, such as dynamic nuclear polarization (DNP) and parahydrogen-induced polarization (PHIP), have revolutionized nuclear magnetic resonance and magnetic resonance imaging. In these methods, a readily available source of high spin order, either electron spins in DNP or singlet states in hydrogen for PHIP, is brought into close proximity with nuclear spin targets, enabling efficient transfer of spin order under external quantum control. Despite vast disparities in energy scales and interaction mechanisms between electron spins in DNP and nuclear singlet states in PHIP, a pseudo-spin formalism allows us to establish an intriguing equivalence. As a result, the important low-field polarization transfer regime of PHIP can be mapped onto an analogous system equivalent to pulsed-DNP. This establishes a correspondence between key polarization transfer sequences in PHIP and DNP, facilitating the transfer of sequence development concepts. This promises fresh insights and significant cross-pollination between DNP and PHIP polarization sequence developers.

核自旋超极化技术,如动态核极化(DNP)和对氢诱导极化(PHIP),给核磁共振和磁共振成像带来了革命性的变化。在这些方法中,现成的高自旋阶数源(DNP 中的电子自旋或 PHIP 中的氢单态)被带到核自旋目标附近,从而在外部量子控制下实现自旋阶数的有效转移。尽管 DNP 中的电子自旋和 PHIP 中的核单子态在能量尺度和相互作用机制上存在巨大差异,但伪自旋形式主义使我们能够建立一种有趣的等价关系。因此,PHIP 的重要低场极化转移机制可以映射到与脉冲 DNP 相当的类似系统上。这就在 PHIP 和 DNP 的关键极化转移序列之间建立了对应关系,促进了序列发展概念的转移。这将为 DNP 和 PHIP 偏振序列开发人员提供新的见解和重要的交叉交流机会。
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引用次数: 0
Unified understanding of the breakdown of thermal mixing dynamic nuclear polarization: The role of temperature and radical concentration 统一理解热混合动态核极化的分解:温度和自由基浓度的作用
IF 2.2 3区 化学 Q3 BIOCHEMICAL RESEARCH METHODS Pub Date : 2024-04-10 DOI: 10.1016/j.jmr.2024.107670
Ludovica M. Epasto , Thibaud Maimbourg , Alberto Rosso , Dennis Kurzbach

We reveal an interplay between temperature and radical concentration necessary to establish thermal mixing (TM) as an efficient dynamic nuclear polarization (DNP) mechanism. We conducted DNP experiments by hyperpolarizing widely used DNP samples, i.e., sodium pyruvate-1-13C in water/glycerol mixtures at varying nitroxide radical (TEMPOL) concentrations and microwave irradiation frequencies, measuring proton and carbon-13 spin temperatures. Using a cryogen consumption-free prototype-DNP apparatus, we could probe cryogenic temperatures between 1.5 and 6.5 K, i.e., below and above the boiling point of liquid helium. We identify two mechanisms for the breakdown of TM: (i) Anderson type of quantum localization for low radical concentration, or (ii) quantum Zeno localization occurring at high temperature. This observation allowed us to reconcile the recent diverging observations regarding the relevance of TM as a DNP mechanism by proposing a unifying picture and, consequently, to find a trade-off between radical concentration and electron relaxation times, which offers a pathway to improve experimental DNP performance based on TM.

我们揭示了温度与自由基浓度之间的相互作用,这种相互作用是将热混合(TM)作为一种有效的动态核极化(DNP)机制所必需的。我们对广泛使用的 DNP 样品,即水/甘油混合物中的丙酮酸钠-1-13C,在不同的亚硝基自由基(TEMPOL)浓度和微波辐照频率下进行了超极化,测量质子和碳-13 的自旋温度,从而开展了 DNP 实验。利用无低温消耗原型-DNP 仪器,我们可以探测 1.5 至 6.5 K 之间的低温,即低于和高于液氦沸点的温度。我们确定了 TM 破裂的两种机制:(i) 低自由基浓度下的安德森量子定位,或 (ii) 高温下发生的量子芝诺定位。这一观察结果使我们能够调和最近关于 TM 作为 DNP 机制的相关性的不同观察结果,提出一个统一的图景,从而找到自由基浓度和电子弛豫时间之间的权衡,这为提高基于 TM 的 DNP 实验性能提供了一条途径。
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引用次数: 0
High-frequency high-power DNP/EPR spectrometer operating at 7 T magnetic field 在 7 T 磁场下运行的高频大功率 DNP/EPR 光谱仪
IF 2.2 3区 化学 Q3 BIOCHEMICAL RESEARCH METHODS Pub Date : 2024-04-10 DOI: 10.1016/j.jmr.2024.107677
Alexander A. Nevzorov, Antonin Marek, Sergey Milikisiyants, Alex I. Smirnov

One of the most essential prerequisites for the development of pulse Dynamic Nuclear Polarization (DNP) is the ability to generate high-power coherent mm-wave pulses at the electron precession frequencies corresponding to the magnetic fields of modern high-resolution NMR spectrometers. As a major step towards achieving this goal, an Extended Interaction Klystron (EIK) pulse amplifier custom-built by the Communications and Power Industries, Inc. and producing up to 140 W at 197.8 GHz, was integrated with in-house built NMR/DNP/EPR spectrometer operating at 7 T magnetic field. The spectrometer employs a Thomas Keating, Ltd. quasioptical bridge to direct mm-waves into a homebuilt DNP probe incorporating photonic bandgap (PBG) resonators to further boost electronic B1e fields. Three-pulse electron spin echo nutation experiments were employed to characterize the B1e fields at the sample by operating the homodyne 198 GHz bridge in an induction mode. Room-temperature experiments with a single-crystal high-pressure, high-temperature (HPHT) diamond and a polystyrene film doped with BDPA radical yielded < 9 ns π/2 pulses at ca. 50 W specified EIK output at the corresponding resonance frequencies and the PBG resonator quality factor of Q≈300. DNP experiments carried out in a “gated” mode by supplying 20 μs mm-wave pulses every 1 ms yielded 13C solid-effect DNP with gains up to 20 for the polystyrene-BDPA sample at natural 13C abundance. For a single-crystal HPHT diamond, the gated DNP mode yielded almost the same 13C enhancement as a low-power continuous wave (CW) mode at 0.4 W, whereas no DNP effect was observed for the BDPA/polystyrene sample in the latter case. To illustrate the versatility of our upgraded DNP spectrometer, room-temperature Overhauser DNP enhancements of 7–14 for 31P NMR signal were demonstrated using a liquid droplet of 1 M tri-phenyl phosphine co-dissolved with 100 mM of BDPA in toluene‑d8.

开发脉冲动态核偏振(DNP)的最基本前提之一是能够在与现代高分辨率 NMR 光谱仪磁场相对应的电子前驱频率上产生大功率相干毫米波脉冲。作为实现这一目标的重要一步,由通信和电力工业公司定制的、在 197.8 GHz 频率下功率高达 140 W 的扩展交互式速调管(EIK)脉冲放大器与内部制造的、在 7 T 磁场下运行的 NMR/DNP/EPR 光谱仪集成在一起。该光谱仪采用托马斯-基廷(Thomas Keating)有限公司生产的准光桥,将毫米波导入自制的 DNP 探头,该探头包含光子带隙(PBG)谐振器,可进一步增强电子 B1e 场。通过在感应模式下操作同频 198 GHz 电桥,利用三脉冲电子自旋回波归零实验来表征样品处的 B1e 场。使用单晶高压高温(HPHT)金刚石和掺杂了 BDPA 自由基的聚苯乙烯薄膜进行的室温实验产生了约 9 ns π/2 脉冲,在约 50 W 的指定 EIK 输出条件下,样品的 B1e 场为 0.5 ns。在相应的共振频率和 Q≈300 的 PBG 谐振器品质因数下,产生了约 50 W 的指定 EIK 输出的 < 9 ns π/2 脉冲。通过每 1 毫秒提供 20 μs 毫米波脉冲的 "门控 "模式进行 DNP 实验,在天然 13C 丰度下,聚苯乙烯-BDPA 样品的 13C 固体效应 DNP 增益高达 20。对于单晶 HPHT 金刚石,门控 DNP 模式产生的 13C 增益几乎与 0.4 W 的低功率连续波 (CW) 模式相同,而在后一种情况下,BDPA/聚苯乙烯样品没有观察到 DNP 效应。为了说明我们升级后的 DNP 光谱仪的多功能性,使用 1 M 三苯基膦与 100 mM BDPA 在甲苯-d8 中共同溶解的液滴演示了室温下 Overhauser DNP 对 31P NMR 信号 7-14 的增强。
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引用次数: 0
Segmented RF shield design to minimize eddy currents for low-field Halbach MRI systems 分段式射频屏蔽设计可最大限度地降低低场哈尔巴赫磁共振成像系统的涡流
IF 2.2 3区 化学 Q3 BIOCHEMICAL RESEARCH METHODS Pub Date : 2024-04-09 DOI: 10.1016/j.jmr.2024.107669
Bart de Vos , Rob Remis , Andrew Webb

MRI systems have a thin conducting layer placed between the gradient and RF coils, this acts as a shield at the RF-frequency, minimizing noise coupled into the experiment, and decreasing the coupling between the RF and gradient coils. Ideally, this layer should be transparent to the gradient fields to reduce eddy currents. In this work the design of such a shield, specifically for low-field point-of-care Halbach based MRI devices, is discussed. A segmented double layer shield is designed and constructed based on eddy current simulations. Subsequently, the performance of the improved shield is compared to a reference shield by measuring the eddy current decay times as well as using noise measurements. A maximum reduction factor of 2.9 in the eddy current decay time is observed. The segmented shield couples in an equivalent amount of noise when compared to the unsegmented reference shield. Turbo spin echo images of a phantom and the brain of a healthy volunteer show improvements in terms of blurring using the segmented shield.

核磁共振成像系统在梯度线圈和射频线圈之间放置了一层薄薄的导电层,作为射频频率的屏蔽层,将耦合到实验中的噪音降至最低,并降低射频线圈和梯度线圈之间的耦合。理想情况下,这一层对梯度场应该是透明的,以减少涡流。本研究讨论了这种屏蔽层的设计,它特别适用于基于哈尔巴赫的低场点核磁共振成像设备。在涡流模拟的基础上,设计并构建了分段式双层屏蔽。随后,通过测量涡流衰减时间和噪声测量,将改进后的屏蔽性能与参考屏蔽进行了比较。结果发现,涡流衰减时间的最大降低系数为 2.9。与未分段的参考屏蔽相比,分段屏蔽耦合了同等数量的噪声。幻影和健康志愿者大脑的涡轮自旋回波图像显示,使用分段屏蔽后,模糊情况有所改善。
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引用次数: 0
Two fields are better than one – A multifunctional (semi)automated setup for quantitative measurements of parahydrogen-induced signal enhancement at low and high fields 两场胜过一场--多功能(半)自动化装置,用于在低场和高场定量测量副氢诱导的信号增强
IF 2.2 3区 化学 Q3 BIOCHEMICAL RESEARCH METHODS Pub Date : 2024-04-09 DOI: 10.1016/j.jmr.2024.107673
Franziska Theiss, Jonas Lins, Jan Kergassner, Laura Wienands, Sonja Döller, Gerd Buntkowsky

The rapid advancement of parahydrogen-induced hyperpolarization (PHIP) and its diverse array of applications highlights the critical need for enhanced signals in both 1H NMR and heteronuclear NMR spectroscopy. Simultaneously, there is an increasing interest in utilizing benchtop NMR analysis across various laboratory settings. However, due to their lower magnetic fields, benchtop NMR spectrometers inherently produce weaker signal intensities. Here, PHIP is a well-established solution to this challenge. Consequently, we are expanding our cost-effective PHIP setup from a high-field NMR spectrometer (11.7 T) to include an additional benchtop NMR spectrometer (1.4 T), thereby enabling concurrent execution of PHIP experiments and measurements. Through the implementation of automated experimental protocols, we aim to minimize experiment time while increasing reproducibility. In this work, a non-isotope labelled propargyl alcohol sample is used at low concentrations to demonstrate our setup’s capabilities. It could be shown that single-scan PASADENA experiments can be run with comparable signal enhancements at the benchtop as well as the high-field spectrometer. At 1.4 T, fully automated PHIP pseudo-2D measurements will also be demonstrated. Additionally, two different field profiles for the spin-order transfer of p-H2 to 13C at zero- to ultralow fields are elaborated upon. The setup facilitates the measurement of carbon signal enhancement of more than 2000 on the benchtop NMR spectrometer, employing a straightforward one-pulse, one-scan experiment.

对氢诱导超极化 (PHIP) 的快速发展及其各种应用凸显了在 1H NMR 和异核 NMR 光谱中增强信号的迫切需要。与此同时,人们对在各种实验室环境中使用台式 NMR 分析的兴趣与日俱增。然而,由于磁场较低,台式 NMR 光谱仪产生的信号强度较弱。PHIP 是应对这一挑战的成熟解决方案。因此,我们正在扩展我们的高性价比 PHIP 设置,从一台高磁场 NMR 光谱仪(11.7 T)扩展到另一台台式 NMR 光谱仪(1.4 T),从而使 PHIP 实验和测量能够同时进行。通过实施自动化实验方案,我们旨在最大限度地缩短实验时间,同时提高可重复性。在这项工作中,我们使用了低浓度的非同位素标记丙炔醇样品,以展示我们装置的能力。结果表明,单扫描 PASADENA 实验可以在台式和高场光谱仪上运行,且信号增强效果相当。在 1.4 T 时,还将演示全自动 PHIP 伪二维测量。此外,还将详细介绍在零场至超低场条件下,p-H2 向 13C 的自旋阶跃转移的两种不同场剖面。该装置采用直接的单脉冲、单扫描实验,可在台式 NMR 光谱仪上测量超过 2000 的碳信号增强。
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引用次数: 0
CTCOSY-JRES: A high-resolution three-dimensional NMR method for unveiling J-couplings CTCOSY-JRES:揭示 J 耦合的高分辨率三维 NMR 方法
IF 2.2 3区 化学 Q3 BIOCHEMICAL RESEARCH METHODS Pub Date : 2024-04-06 DOI: 10.1016/j.jmr.2024.107675
Xiaoqing Lin, Yulei Chen, Chengda Huang, Xiaozhen Feng, Bo Chen, Yuqing Huang, Zhong Chen

Two-dimensional (2D) J-resolved spectroscopy provides valuable information on J-coupling constants for molecular structure analysis by resolving one-dimensional (1D) spectra. However, it is challenging to decipher the J-coupling connectivity in 2D J-resolved spectra because the J-coupling connectivity cannot be directly provided. In addition, 2D homonuclear correlation spectroscopy (COSY) can directly elucidate molecular structures by tracking the J-coupling connectivity between protons. However, this method is limited by the problem of spectral peak crowding and is only suitable for simple sample systems. To fully understand the intuitive coupling relationship and coupling constant information, we propose a three-dimensional (3D) COSY method called CTCOSY-JRES (Constant-Time COrrelation SpectroscopY and J-REsolved Spectroscopy) in this paper. By combining the J-resolved spectrum with the constant-time COSY technique, a doubly decoupled COSY spectrum can be provided while preserving the J-coupling constant along an additional dimension, ensuring high-resolution analysis of J-coupling connectivity and J-coupling information. Moreover, compression sensing and fold-over correction techniques are introduced to accelerate experimental acquisition. The CTCOSY-JRES method has been successfully validated in a variety of sample systems, including industrial, agricultural, and biopharmaceutical samples, revealing complex coupling interactions and providing deeper insights into the resolution of molecular structures.

二维(2D)J 分辨光谱通过解析一维(1D)光谱,为分子结构分析提供了有关 J 耦合常数的宝贵信息。然而,由于二维 J 分辨光谱无法直接提供 J 耦合连通性,因此破译 J 耦合连通性具有挑战性。此外,二维同核相关光谱(COSY)可通过跟踪质子间的 J 耦合连通性直接阐明分子结构。然而,这种方法受到光谱峰拥挤问题的限制,只适用于简单的样品体系。为了充分了解直观的耦合关系和耦合常数信息,我们在本文中提出了一种三维(3D)COSY 方法,称为 CTCOSY-JRES(Constant-Time COrrelation SpectroscopY and J-REsolved Spectroscopy)。通过将 J 分辨光谱与恒时 COSY 技术相结合,可以提供双重解耦 COSY 光谱,同时沿额外维度保留 J 耦合常数,从而确保对 J 耦合连通性和 J 耦合信息进行高分辨率分析。此外,还引入了压缩感应和折叠校正技术,以加速实验采集。CTCOSY-JRES 方法已在多种样品系统中成功验证,包括工业、农业和生物制药样品,揭示了复杂的耦合相互作用,为解析分子结构提供了更深入的见解。
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引用次数: 0
Clean PDI-1 SQ: Suppression of HSQC artifacts in 2D proton-detected INADEQUATE spectra by pulse sequence redesign 清洁 PDI-1 SQ:通过重新设计脉冲序列抑制二维质子检测 INADEQUATE 光谱中的 HSQC 伪影
IF 2.2 3区 化学 Q3 BIOCHEMICAL RESEARCH METHODS Pub Date : 2024-04-06 DOI: 10.1016/j.jmr.2024.107674
Justinas Sakas , Dušan Uhrín , Ole W. Sørensen

Proton-detected INADEQUATE NMR experiments are widely used for structure elucidation of small molecules, in particular the implementations that display 13C single-quantum rather than double-quantum frequencies in the indirect dimension of 2D spectra. But unfortunately, such spectra in addition to the desired 1H–13C two-bond correlations also contain HSQC artifacts of comparable magnitude. The redesigned versatile experiment presented in this paper requires no compromise based on different 13C multiplicities and suppresses the HSQC artifacts that are a source of possible spectral misinterpretation. Demonstration of the new method is shown by applications to typical small molecules of different complexity.

质子检测的非等效核磁共振实验被广泛用于小分子的结构阐释,尤其是在二维光谱的间接维度上显示 13C 单量子频率而非双量子频率的实施方案。但遗憾的是,这种光谱除了显示所需的 1H-13C 双键相关性外,还包含程度相当的 HSQC 伪影。本文介绍的重新设计的多功能实验无需根据不同的 13C 倍率进行折衷,并抑制了可能导致光谱误读的 HSQC 伪影。新方法通过应用于不同复杂程度的典型小分子进行了演示。
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引用次数: 0
MaRGE: A graphical environment for MaRCoS MaRGE:MaRCoS 的图形环境
IF 2.2 3区 化学 Q3 BIOCHEMICAL RESEARCH METHODS Pub Date : 2024-04-01 DOI: 10.1016/j.jmr.2024.107662
José M. Algarín , Teresa Guallart-Naval , José Borreguero , Fernando Galve , Joseba Alonso

The open-source console MaRCoS, which stands for “Magnetic Resonance Control System”, combines hardware, firmware and software elements for integral control of Magnetic Resonance Imaging (MRI) scanners. Previous developments have focused on making the system robust and reliable, rather than on users, who have been somewhat overlooked. This work describes a Graphical User Interface (GUI) designed for intuitive control of MaRCoS, as well as compatibility with clinical environments. The GUI is based on an arrangement of tabs and a renewed Application Program Interface (API). Compared to the previous versions, the MaRGE package (“MaRCoS Graphical Environment”) includes new functionalities such as the possibility to export images to standard DICOM formats, create and manage clinical protocols, or display and process image reconstructions, among other features conceived to simplify the operation of MRI scanners. All prototypes in our facilities are commanded by MaRCoS and operated with the new GUI. Here we report on its performance on an experimental 0.2 T scanner designed for hard-tissue, as well as a 72 mT portable scanner presently installed in the radiology department of a large hospital. The possibility to customize, adapt and streamline processes has substantially improved our workflows and overall experience.

开源控制台 MaRCoS 是 "磁共振控制系统 "的缩写,结合了硬件、固件和软件元素,可对磁共振成像(MRI)扫描仪进行整体控制。以前的开发工作主要集中在系统的稳健性和可靠性上,而不是用户,用户在一定程度上被忽视了。这项工作描述了一个图形用户界面(GUI),旨在直观地控制 MaRCoS,并与临床环境兼容。图形用户界面以标签排列和更新的应用程序接口(API)为基础。与之前的版本相比,MaRGE软件包("MaRCoS图形环境")包含了新的功能,例如可以将图像导出为标准的DICOM格式、创建和管理临床协议、显示和处理图像重建,以及其他旨在简化核磁共振成像扫描仪操作的功能。我们设施中的所有原型机都由 MaRCoS 指挥,并使用新的图形用户界面进行操作。在此,我们报告了它在一台专为硬组织设计的 0.2 T 实验扫描仪和一台目前安装在一家大型医院放射科的 72 mT 便携式扫描仪上的表现。自定义、调整和简化流程的可能性大大改善了我们的工作流程和整体体验。
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引用次数: 0
NMR measurement of diffusion coefficients by radio-frequency gradients in the case of short relaxation times 在弛豫时间较短的情况下利用射频梯度进行核磁共振扩散系数测量
IF 2.2 3区 化学 Q3 BIOCHEMICAL RESEARCH METHODS Pub Date : 2024-04-01 DOI: 10.1016/j.jmr.2024.107668
Laouès Guendouz , Sébastien Leclerc , Daniel Canet

The measurement of translational diffusion coefficients by NMR generally makes use basically of two magnetic field gradient pulses separated by a so-called diffusion interval. The magnetic field gradient arises either from the static magnetic field (denoted by B0 used for polarizing the nuclear spins) or from the radio-frequency field (denoted by B1 used for inducing NMR transitions). The B0 method may be hampered by short effective transverse relaxation times (T2), by important gradient rise and fall times or by eddy currents. This does not occur with B1 gradients. Moreover, the effect of short transverse relaxation times during the gradient pulses is reduced by at least a factor of two. However, for B1 gradients, one might face with the limited volume in which the gradient is uniform and with the effect of short relaxation times which imply to reduce the various intervals in the diffusion experiment (this is as well true for the B0 method). Examples will be given for which the measurement of the diffusion coefficient by B0 gradients turned out to be impossible while a proper result was obtained with B1 gradients as far as a correction taking into account the limited volume is applied, together with a correction about the gradient calibration especially when dealing with samples containing paramagnetic species.

利用核磁共振测量平移扩散系数时,通常使用两个磁场梯度脉冲,这两个脉冲之间有一个所谓的扩散间隔。磁场梯度要么来自静态磁场(用 B0 表示,用于极化核自旋),要么来自射频场(用 B1 表示,用于诱导 NMR 转变)。短的有效横向弛豫时间 (T2∗)、重要的梯度上升和下降时间或涡流可能会妨碍 B0 方法。而 B1 梯度则不会出现这种情况。此外,在梯度脉冲期间,短横向弛豫时间的影响至少会减少两倍。然而,对于 B1 梯度,人们可能会面临梯度均匀的体积有限以及弛豫时间短的影响,这意味着要减少扩散实验中的各种间隔(这对于 B0 方法也是如此)。我们将举例说明 B0 梯度法无法测量扩散系数的情况,而 B1 梯度法只要考虑到有限的体积并对梯度校准(尤其是在处理含有顺磁性物质的样品时)进行修正,就能获得正确的结果。
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引用次数: 0
A delayed decoupling methyl-TROSY pulse sequence for atomic resolution studies of folded proteins and RNAs in condensates 用于凝结物中折叠蛋白质和 RNA 原子分辨率研究的延迟去耦甲基-TROSY 脉冲序列
IF 2.2 3区 化学 Q3 BIOCHEMICAL RESEARCH METHODS Pub Date : 2024-03-28 DOI: 10.1016/j.jmr.2024.107667
Rashik Ahmed , Atul K. Rangadurai , Lisa Ruetz , Martin Tollinger , Christoph Kreutz , Lewis E. Kay

Solution NMR spectroscopy has tremendous potential for providing atomic resolution insights into the interactions between proteins and nucleic acids partitioned into condensed phases of phase-separated systems. However, the highly viscous nature of the condensed phase challenges applications, and in particular, the extraction of quantitative, site-specific information. Here, we present a delayed decoupling-based HMQC pulse sequence for methyl-TROSY studies of ‘client’ proteins and nucleic acids partitioned into ‘scaffold’ proteinaceous phase-separated solvents. High sensitivity and excellent quality spectra are recorded of a nascent form of superoxide dismutase and of a small RNA fragment partitioned into CAPRIN1 condensates.

溶液核磁共振光谱具有巨大的潜力,可提供原子分辨率,深入了解分隔在相分离系统凝聚相中的蛋白质和核酸之间的相互作用。然而,凝聚相的高粘性给应用带来了挑战,尤其是在提取定量的特定位点信息方面。在此,我们介绍了一种基于延迟解耦的 HMQC 脉冲序列,用于对 "支架 "蛋白质相分离溶剂中的 "客户 "蛋白质和核酸进行甲基-TROSY 研究。研究人员记录了超氧化物歧化酶的新生形式和分入 CAPRIN1 凝聚物的小 RNA 片段的高灵敏度和高质量光谱。
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Journal of magnetic resonance
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