{"title":"Automatic Optimization of Pulse Sequences Based on a Closed-Loop Control Strategy","authors":"Guanghui Shi, Lizhi Xiao, Guangzhi Liao, Sihui Luo, Xueli Hou, Huaxue Liu, Jian Zhong, Jihong Liu","doi":"10.1007/s00723-023-01633-9","DOIUrl":"10.1007/s00723-023-01633-9","url":null,"abstract":"<div><p>Generally, the pulse sequence parameters and acquisition parameters of nuclear magnetic resonance (NMR) logging tools are determined before logging and kept unchanged during logging. Because the detection area changes constantly during logging, the preset parameters are often not the best for different detection objectives, the energy consumption and sampling resolution will be reduced. To solve this problem, we propose a closed-loop control scheme for parameter optimization, which achieves the dynamic regulation of parameters according to the relaxation characteristics of the samples. The closed-loop control system has been implemented in a laboratory core analyzer to prove the effectiveness of the variable TE sequence as a reconnaissance sequence. When the sample changes, the control system can guide the control circuit to switch to the Carr-Purcell-Meiboom-Gill (CPMG) pulse sequence with appropriate parameters in a timely manner. Compared with conventional parameter setting methods, this scheme can better avoid insufficient attenuation of the echo train or excessive data collection caused by the improper setting of pulse train length while reducing energy consumption during measurements.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"55 4","pages":"429 - 441"},"PeriodicalIF":1.1,"publicationDate":"2023-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138508263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Site-Directed Fluorescence Labeling (SDFL): TrIQ Methods Provide Insights Using the Fluorescent Probe Bimane","authors":"Anthony D. Shumate, David L. Farrens","doi":"10.1007/s00723-023-01628-6","DOIUrl":"10.1007/s00723-023-01628-6","url":null,"abstract":"<div><p>This review is in honor of Professor Wayne Hubbell’s 80th birthday, and his many contributions to the philosophy and practice of science. He continues to pioneer the use of site-directed spin labeling (SDSL) as a powerful tool for studying protein structure and dynamics. Inspired by his efforts, our lab has worked to develop site-directed fluorescence labeling (SDFL) as a complementary approach to SDSL. Throughout this process, we have emulated many of the novel methods and concepts Dr. Hubbell and his colleagues used during their development of SDSL. Some of our approaches are discussed here, not in a comprehensive or exhaustive way, but to highlight SDFL methods we have found to be robust, reproducible, and relatively easy to use. Specifically, we will focus on the development and application of SDFL using the fluorescent probe bimane, and how the unique properties of bimane can be exploited to glean information about protein structure and function. We also review past examples of how we have used bimane and SDFL to investigate the activation of G protein-coupled receptors (GPCRs) and their interaction with key binding partners.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"55 1-3","pages":"101 - 126"},"PeriodicalIF":1.1,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138508274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Nonlinear Chirp Sequence for Broadband (pi ) Rotation Using Hyperbolic Secant Pulse","authors":"Sambeda Sarkar, Pradyumna Paruchuri, Navin Khaneja","doi":"10.1007/s00723-023-01630-y","DOIUrl":"10.1007/s00723-023-01630-y","url":null,"abstract":"<div><p>This article introduces an approach to implement a wide-range <span>(pi )</span> rotation in nuclear magnetic resonance (NMR) spectroscopy using nonlinear chirp pulse sequences. The rotation pulse sequences consist of hyperbolic-secant (HS) pulses and are specifically designed to serve as efficient refocusing pulse elements in spin echo sequences. The composite pulse sequences are composed of three pulse elements, which undergo adiabatic full passage at specific rates chosen to compensate phase distortion incurred. We explore various combinations of these HS pulse sequences, all of which achieve a broadband <span>((pi )_y)</span> rotation. The theory behind these composite hyperbolic secant pulse sequences is detailed, along with simulations and experimental results. For experimental implementation, we employ phase modulated pulse sequences and the experimental measurements are performed on a <span>({750,mathrm{text {M}text {Hz}}})</span> spectrometer using a sample consisting of <span>(99.5% text {D}_2text {O})</span> and <span>(0.5% text {H}_2text {O})</span>.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"55 4","pages":"399 - 416"},"PeriodicalIF":1.1,"publicationDate":"2023-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134957152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Bernhard Blümich: On the Occasion of His 70th Birthday","authors":"Matthew Augustine, Peter Blümler, Jeffrey Reimer","doi":"10.1007/s00723-023-01631-x","DOIUrl":"10.1007/s00723-023-01631-x","url":null,"abstract":"","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"54 11-12","pages":"1065 - 1067"},"PeriodicalIF":1.0,"publicationDate":"2023-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00723-023-01631-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135137821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xueqin Wang, Xi Ye, Xiaoping Qin, Yi Fu, Hong Tang
{"title":"Glutathione-Responsive T1 Contrast Agent for Tumor Imaging","authors":"Xueqin Wang, Xi Ye, Xiaoping Qin, Yi Fu, Hong Tang","doi":"10.1007/s00723-023-01629-5","DOIUrl":"10.1007/s00723-023-01629-5","url":null,"abstract":"<div><p>Tumor microenvironment responsive probe holds great potential to achieve precise diagnosis owning to its capacity to show different signal in tumor and normal tissue. Here, we develop an intelligent magnetic resonance imaging (MRI) contrast agent (CA) with the capacity to rapidly respond to GSH. This intelligent MRI CA keep in “off” state in normal tissue while degrade into manganese ions and exhibit “on” state in tumor lesion. This unique feature endows this activable MRI CA to fulfill accurate tumor detection. Besides, this intelligent CA show negligible cytotoxicity to cell and mice, indicating its excellent biocompatibility and immense potential to biological application. This work develops a new activable MRI CA to sensitively detect tumor and provides guidelines to design new activable MRI CA for precise diagnosis.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"55 4","pages":"387 - 397"},"PeriodicalIF":1.1,"publicationDate":"2023-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135243409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Correction: Dynamic Nature of Proteins is Critically Important for Their Function: GPCRs and Signal Transducers","authors":"Vsevolod V. Gurevich, Eugenia V. Gurevich","doi":"10.1007/s00723-023-01627-7","DOIUrl":"10.1007/s00723-023-01627-7","url":null,"abstract":"","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"55 1-3","pages":"27 - 27"},"PeriodicalIF":1.1,"publicationDate":"2023-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135773598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Raphael Kircher, Sarah Mross, Hans Hasse, Kerstin Münnemann
{"title":"Quantitative Analysis in Continuous-Flow (^1)H Benchtop NMR Spectroscopy by Paramagnetic Relaxation Enhancement","authors":"Raphael Kircher, Sarah Mross, Hans Hasse, Kerstin Münnemann","doi":"10.1007/s00723-023-01626-8","DOIUrl":"10.1007/s00723-023-01626-8","url":null,"abstract":"<div><p>Nuclear magnetic resonance (NMR) spectroscopy is an excellent tool for reaction and process monitoring. Process monitoring is often carried out online, where the analytic device is operated in flow mode. Benchtop NMR spectrometers are especially well-suited for these applications because they can be installed close to the studied process. However, quantitative analysis of a fast-flowing liquid with NMR spectroscopy is challenging because short residence times in the magnetic field of the spectrometer result in inefficient polarization buildup and thus poor signal intensity. This is particularly problematic for benchtop NMR spectrometers, where it severely limits the flow velocity in quantitative measurements. One method for increasing polarization in continuous-flow NMR spectroscopy is paramagnetic relaxation enhancement (PRE). Here, the interaction of the studied liquid with a PRE agent significantly accelerates the buildup of nuclear polarization prior to NMR detection, which enables quantitative measurements at high flow velocities. For process monitoring applications, the synthesis of robust and chemically inert immobilized PRE agents is mandatory. This was accomplished in the present work, where a new PRE agent is tested on 12 common solvents including water, acetonitrile, 1,4-dioxane, and binary mixtures with quantitative benchtop <span>(^1)</span>H NMR spectroscopy at 1 Tesla. The results show that the flow regime for quantitative measurements can be greatly extended by the use of the synthesized PRE agent.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"54 11-12","pages":"1555 - 1569"},"PeriodicalIF":1.0,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00723-023-01626-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135818567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Francine A. F. Menezes, Jurandi G. Oliveira, André O. Guimarães
{"title":"Electron Paramagnetic Resonance Applied to Free Radicals and Reactive Oxygen Species Detection in Plant Systems","authors":"Francine A. F. Menezes, Jurandi G. Oliveira, André O. Guimarães","doi":"10.1007/s00723-023-01625-9","DOIUrl":"10.1007/s00723-023-01625-9","url":null,"abstract":"<div><p>Electron paramagnetic resonance (EPR) is a non-invasive and highly sensitive technique that has been extensively used for detecting free radicals and reactive oxygen species (ROS) in biological systems. In plant biology, ROS are highly reactive and play a critical role in regulating various cellular processes. However, detecting ROS in plant systems is challenging due to their short half-life and low concentrations. This review presents a comprehensive overview of the application of EPR for the detection of free radicals and ROS in plant systems, including a comparison with other methods. Furthermore, it explores the utilization of the spin trapping method in combination with EPR for ROS detection, providing spectroscopic parameters for numerous spin trap compounds. We highlight some of the relevant studies that used EPR spectroscopy to detect ROS, as well as stable radicals, in plant systems. This review serves as a valuable resource for researchers interested in using EPR spectroscopy for free radicals and ROS detection in plant systems and provides insights into the current state of the field and future research trends.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"55 4","pages":"335 - 355"},"PeriodicalIF":1.1,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136381544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mengzhen Chen, Tamás Kálai, Duilio Cascio, Michael D. Bridges, Julian P. Whitelegge, Matthias Elgeti, Wayne L. Hubbell
{"title":"A Highly Ordered Nitroxide Side Chain for Distance Mapping and Monitoring Slow Structural Fluctuations in Proteins","authors":"Mengzhen Chen, Tamás Kálai, Duilio Cascio, Michael D. Bridges, Julian P. Whitelegge, Matthias Elgeti, Wayne L. Hubbell","doi":"10.1007/s00723-023-01618-8","DOIUrl":"10.1007/s00723-023-01618-8","url":null,"abstract":"<div><p>Site-directed spin labeling electron paramagnetic resonance (SDSL-EPR) is an established tool for exploring protein structure and dynamics. Although nitroxide side chains attached to a single cysteine via a disulfide linkage are commonly employed in SDSL-EPR, their internal flexibility complicates applications to monitor slow internal motions in proteins and to structure determination by distance mapping. Moreover, the labile disulfide linkage prohibits the use of reducing agents often needed for protein stability. To enable the application of SDSL-EPR to the measurement of slow internal dynamics, new spin labels with hindered internal motion are desired. Here, we introduce a highly ordered nitroxide side chain, designated R9, attached at a single cysteine residue via a non-reducible thioether linkage. The reaction to introduce R9 is highly selective for solvent-exposed cysteine residues. Structures of R9 at two helical sites in T4 Lysozyme were determined by X-ray crystallography and the mobility in helical sequences was characterized by EPR spectral lineshape analysis, Saturation Transfer EPR, and Saturation Recovery EPR. In addition, interspin distance measurements between pairs of R9 residues are reported. Collectively, all data indicate that R9 will be useful for monitoring slow internal structural fluctuations, and applications to distance mapping via dipolar spectroscopy and relaxation enhancement methods are anticipated.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"55 1-3","pages":"251 - 277"},"PeriodicalIF":1.1,"publicationDate":"2023-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00723-023-01618-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135766151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Structural Dynamics of Protein Interactions Using Site-Directed Spin Labeling of Cysteines to Measure Distances and Rotational Dynamics with EPR Spectroscopy","authors":"Osha Roopnarine, David D. Thomas","doi":"10.1007/s00723-023-01623-x","DOIUrl":"10.1007/s00723-023-01623-x","url":null,"abstract":"<div><p>Here we review applications of site-directed spin labeling (SDSL) with engineered cysteines in proteins, to study the structural dynamics of muscle and non-muscle proteins, using and developing the electron paramagnetic resonance (EPR) spectroscopic techniques of dipolar EPR, double electron electron resonance (DEER), saturation transfer EPR (STEPR), and orientation measured by EPR. The SDSL technology pioneered by Wayne Hubbell and collaborators has greatly expanded the use of EPR, including the measurement of distances between spin labels covalently attached to proteins and peptides. The Thomas lab and collaborators have applied these techniques to elucidate dynamic interactions in the myosin–actin complex, myosin-binding protein C, calmodulin, ryanodine receptor, phospholamban, utrophin, dystrophin, β-III-spectrin, and Aurora kinase. The ability to design and engineer cysteines in proteins for site-directed covalent labeling has enabled the use of these powerful EPR techniques to measure distances, while showing that they are complementary with optical spectroscopy measurements.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"55 1-3","pages":"79 - 100"},"PeriodicalIF":1.1,"publicationDate":"2023-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00723-023-01623-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136097719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}