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Journal articles on the topic 'SsNMR spectroscopy'

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Author: Grafiati
Published: 10 December 2022
Last updated: 29 January 2023

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1

He, Lichun, Benjamin Bardiaux, Mumdooh Ahmed, Johannes Spehr, Renate König, Heinrich Lünsdorf, Ulfert Rand, Thorsten Lührs, and Christiane Ritter. "Structure determination of helical filaments by solid-state NMR spectroscopy." Proceedings of the National Academy of Sciences 113, no. 3 (January 5, 2016): E272—E281. http://dx.doi.org/10.1073/pnas.1513119113.

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The controlled formation of filamentous protein complexes plays a crucial role in many biological systems and represents an emerging paradigm in signal transduction. The mitochondrial antiviral signaling protein (MAVS) is a central signal transduction hub in innate immunity that is activated by a receptor-induced conversion into helical superstructures (filaments) assembled from its globular caspase activation and recruitment domain. Solid-state NMR (ssNMR) spectroscopy has become one of the most powerful techniques for atomic resolution structures of protein fibrils. However, for helical filaments, the determination of the correct symmetry parameters has remained a significant hurdle for any structural technique and could thus far not be precisely derived from ssNMR data. Here, we solved the atomic resolution structure of helical MAVSCARD filaments exclusively from ssNMR data. We present a generally applicable approach that systematically explores the helical symmetry space by efficient modeling of the helical structure restrained by interprotomer ssNMR distance restraints. Together with classical automated NMR structure calculation, this allowed us to faithfully determine the symmetry that defines the entire assembly. To validate our structure, we probed the protomer arrangement by solvent paramagnetic resonance enhancement, analysis of chemical shift differences relative to the solution NMR structure of the monomer, and mutagenesis. We provide detailed information on the atomic contacts that determine filament stability and describe mechanistic details on the formation of signaling-competent MAVS filaments from inactive monomers.
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van der Wel, Patrick C. A. "New applications of solid-state NMR in structural biology." Emerging Topics in Life Sciences 2, no. 1 (February 23, 2018): 57–67. http://dx.doi.org/10.1042/etls20170088.

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Various recent developments in solid-state nuclear magnetic resonance (ssNMR) spectroscopy have enabled an array of new insights regarding the structure, dynamics, and interactions of biomolecules. In the ever more integrated world of structural biology, ssNMR studies provide structural and dynamic information that is complementary to the data accessible by other means. ssNMR enables the study of samples lacking a crystalline lattice, featuring static as well as dynamic disorder, and does so independent of higher-order symmetry. The present study surveys recent applications of biomolecular ssNMR and examines how this technique is increasingly integrated with other structural biology techniques, such as (cryo) electron microscopy, solution-state NMR, and X-ray crystallography. Traditional ssNMR targets include lipid bilayer membranes and membrane proteins in a lipid bilayer environment. Another classic application has been in the area of protein misfolding and aggregation disorders, where ssNMR has provided essential structural data on oligomers and amyloid fibril aggregates. More recently, the application of ssNMR has expanded to a growing array of biological assemblies, ranging from non-amyloid protein aggregates, protein–protein complexes, viral capsids, and many others. Across these areas, multidimensional magic angle spinning (MAS) ssNMR has, in the last decade, revealed three-dimensional structures, including many that had been inaccessible by other structural biology techniques. Equally important insights in structural and molecular biology derive from the ability of MAS ssNMR to probe information beyond comprehensive protein structures, such as dynamics, solvent exposure, protein–protein interfaces, and substrate–enzyme interactions.
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3

Robin, Marc, Stanislas Von Euw, Guillaume Renaudin, Sandrine Gomes, Jean-Marc Krafft, Nadine Nassif, Thierry Azaïs, and Guylène Costentin. "Insights into OCP identification and quantification in the context of apatite biomineralization." CrystEngComm 22, no. 16 (2020): 2728–42. http://dx.doi.org/10.1039/c9ce01972c.

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4

Middleton, D. A. "Solid-state NMR spectroscopy as a tool for drug design: from membrane-embedded targets to amyloid fibrils." Biochemical Society Transactions 35, no. 5 (October 25, 2007): 985–90. http://dx.doi.org/10.1042/bst0350985.

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Structure-based design has gained credibility as a valuable component of the modern drug discovery process. The technique of SSNMR (solid-state NMR) promises to be a useful counterpart to the conventional experimental techniques of X-ray crystallography and solution-state NMR for providing structural features of drug targets that can guide medicinal chemistry towards drug candidates. This article highlights some recent SSNMR approaches from our group for identifying active compounds, such as enzyme inhibitors, receptor antagonists and peptide agents, that prevent the aggregation of amyloid proteins involved in neurodegenerative diseases. It is anticipated that the use of SSNMR in drug discovery will become more widespread in the wake of advances in hardware and methodological developments.
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5

Sreemantula, Arun Kumar, and Alexander Marchanka. "Solid-state NMR spectroscopy for characterization of RNA and RNP complexes." Biochemical Society Transactions 48, no. 3 (June 23, 2020): 1077–87. http://dx.doi.org/10.1042/bst20191080.

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Ribonucleic acids are driving a multitude of biological processes where they act alone or in complex with proteins (ribonucleoproteins, RNP). To understand these processes both structural and mechanistic information about RNA is necessary. Due to their conformational plasticity RNA pose a challenge for mainstream structural biology methods. Solid-state NMR (ssNMR) spectroscopy is an emerging technique that can be applied to biomolecular complexes of any size in close-to-native conditions. This review outlines recent methodological developments in ssNMR for structural characterization of RNA and protein–RNA complexes and provides relevant examples.
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6

Ader, C., R. Schneider, K. Seidel, M. Etzkorn, and M. Baldus. "Magic-angle-spinning NMR spectroscopy applied to small molecules and peptides in lipid bilayers." Biochemical Society Transactions 35, no. 5 (October 25, 2007): 991–95. http://dx.doi.org/10.1042/bst0350991.

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ssNMR (solid-state NMR) spectroscopy provides increasing possibilities to study the structural and dynamic aspects of biological membranes. Here, we review recent ssNMR experiments that are based on MAS (magic angle spinning) and that provide insight into the structure and dynamics of membrane systems at the atomic level. Such methods can be used to study membrane architecture, domain formation or molecular complexation in a way that is highly complementary to other biophysical methods such as imaging or calorimetry.
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7

Zhao, Li, Wei Li, Andreas Plog, Yeping Xu, Gerd Buntkowsky, Torsten Gutmann, and Kai Zhang. "Multi-responsive cellulose nanocrystal–rhodamine conjugates: an advanced structure study by solid-state dynamic nuclear polarization (DNP) NMR." Phys. Chem. Chem. Phys. 16, no. 47 (2014): 26322–29. http://dx.doi.org/10.1039/c4cp04096a.

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8

Siudem, Paweł, Jarosław Bukowicki, Iwona Wawer, and Katarzyna Paradowska. "Structural studies of two capsaicinoids: dihydrocapsaicin and nonivamide. 13C and 15N MAS NMR supported by genetic algorithm and GIAO DFT calculations." RSC Advances 10, no. 31 (2020): 18082–92. http://dx.doi.org/10.1039/d0ra01320j.

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9

Zhao, Sha, Yufei Yang, Yujie Zhao, Xinming Li, Yi Xue, and Shenlin Wang. "High-resolution solid-state NMR spectroscopy of hydrated non-crystallized RNA." Chemical Communications 55, no. 93 (2019): 13991–94. http://dx.doi.org/10.1039/c9cc06552k.

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10

Mandala, Venkata S., Jonathan K. Williams, and Mei Hong. "Structure and Dynamics of Membrane Proteins from Solid-State NMR." Annual Review of Biophysics 47, no. 1 (May 20, 2018): 201–22. http://dx.doi.org/10.1146/annurev-biophys-070816-033712.

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Solid-state nuclear magnetic resonance (SSNMR) spectroscopy elucidates membrane protein structures and dynamics in atomic detail to yield mechanistic insights. By interrogating membrane proteins in phospholipid bilayers that closely resemble biological membranes, SSNMR spectroscopists have revealed ion conduction mechanisms, substrate transport dynamics, and oligomeric interfaces of seven-transmembrane helix proteins. Research has also identified conformational plasticity underlying virus-cell membrane fusions by complex protein machineries, and β-sheet folding and assembly by amyloidogenic proteins bound to lipid membranes. These studies collectively show that membrane proteins exhibit extensive structural plasticity to carry out their functions. Because of the inherent dependence of NMR frequencies on molecular orientations and the sensitivity of NMR frequencies to dynamical processes on timescales from nanoseconds to seconds, SSNMR spectroscopy is ideally suited to elucidate such structural plasticity, local and global conformational dynamics, protein-lipid and protein-ligand interactions, and protonation states of polar residues. New sensitivity-enhancement techniques, resolution enhancement by ultrahigh magnetic fields, and the advent of 3D and 4D correlation NMR techniques are increasingly aiding these mechanistically important structural studies.
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11

López, C., R. M. Claramunt, M. P. Cabildo, C. Pérez-Medina, M. C. Torralba, and M. R. Torres. "SSNMR spectroscopy and X-ray crystallography of fluorinated indazolinones." Acta Crystallographica Section A Foundations of Crystallography 67, a1 (August 22, 2011): C816. http://dx.doi.org/10.1107/s0108767311079311.

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12

Reviglio, Ana L., Fernando A. Martínez, Marcos D. A. Montero, Yamila Garro-Linck, Gustavo A. Aucar, Norma R. Sperandeo, and Gustavo A. Monti. "Accurate location of hydrogen atoms in hydrogen bonds of tizoxanide from the combination of experimental and theoretical models." RSC Advances 11, no. 13 (2021): 7644–52. http://dx.doi.org/10.1039/d0ra10609g.

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13

Liu, Zhengmao, Lixin Liang, Dong Xiao, Yi Ji, Zhenchao Zhao, Jun Xu, and Guangjin Hou. "89Y chemical shift anisotropy: a sensitive structural probe of layered yttrium hydroxides revealed by solid-state NMR spectroscopy and DFT calculations." Physical Chemistry Chemical Physics 23, no. 48 (2021): 27244–52. http://dx.doi.org/10.1039/d1cp04247e.

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14

Wang, Xue Lu, Wen Qi Fang, Wenqing Liu, Yi Jia, Dengwei Jing, Yun Wang, Ling-Yun Yang, et al. "Brønsted base site engineering of graphitic carbon nitride for enhanced photocatalytic activity." Journal of Materials Chemistry A 5, no. 36 (2017): 19227–36. http://dx.doi.org/10.1039/c7ta06602c.

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15

Namespetra, Andrew M., David A. Hirsh, Marcel P. Hildebrand, Anthony R. Sandre, Hiyam Hamaed, Jeremy M. Rawson, and Robert W. Schurko. "35Cl solid-state NMR spectroscopy of HCl pharmaceuticals and their polymorphs in bulk and dosage forms." CrystEngComm 18, no. 33 (2016): 6213–32. http://dx.doi.org/10.1039/c6ce01069e.

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16

Chakraborty, Arnab, Fabien Deligey, Jenny Quach, Frederic Mentink-Vigier, Ping Wang, and Tuo Wang. "Biomolecular complex viewed by dynamic nuclear polarization solid-state NMR spectroscopy." Biochemical Society Transactions 48, no. 3 (May 7, 2020): 1089–99. http://dx.doi.org/10.1042/bst20191084.

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Solid-state nuclear magnetic resonance (ssNMR) is an indispensable tool for elucidating the structure and dynamics of insoluble and non-crystalline biomolecules. The recent advances in the sensitivity-enhancing technique magic-angle spinning dynamic nuclear polarization (MAS-DNP) have substantially expanded the territory of ssNMR investigations and enabled the detection of polymer interfaces in a cellular environment. This article highlights the emerging MAS-DNP approaches and their applications to the analysis of biomolecular composites and intact cells to determine the folding pathway and ligand binding of proteins, the structural polymorphism of low-populated biopolymers, as well as the physical interactions between carbohydrates, proteins, and lignin. These structural features provide an atomic-level understanding of many cellular processes, promoting the development of better biomaterials and inhibitors. It is anticipated that the capabilities of MAS-DNP in biomolecular and biomaterial research will be further enlarged by the rapid development of instrumentation and methodology.
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17

Kilpatrick, Alexander F. R., Nicholas H. Rees, Zoë R. Turner, Jean-Charles Buffet, and Dermot O’Hare. "Physicochemical surface-structure studies of highly active zirconocene polymerisation catalysts on solid polymethylaluminoxane activating supports." Materials Chemistry Frontiers 4, no. 11 (2020): 3226–33. http://dx.doi.org/10.1039/d0qm00482k.

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Static 91Zr ssNMR, SEM-EDX, and DRIFT spectroscopy indicate that a common zirconium species, [CpR2ZrMe]+, is present in all sMAO supported catalyst systems.
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18

Chen, Zheng, Aleksander Jaworski, Jianhong Chen, Tetyana M. Budnyak, Ireneusz Szewczyk, Anna Rokicińska, Richard Dronskowski, Niklas Hedin, Piotr Kuśtrowski, and Adam Slabon. "Graphitic nitrogen in carbon catalysts is important for the reduction of nitrite as revealed by naturally abundant 15N NMR spectroscopy." Dalton Transactions 50, no. 20 (2021): 6857–66. http://dx.doi.org/10.1039/d1dt00658d.

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Directly-excited 15N ssNMR spectroscopy at natural 15N abundance is generally capable of providing information on N-doped carbon materials and therefore of elucidating the catalytic activity at the atomic level.
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19

Munro, Rachel, Jeffrey de Vlugt, Vladimir Ladizhansky, and Leonid S. Brown. "Improved Protocol for the Production of the Low-Expression Eukaryotic Membrane Protein Human Aquaporin 2 in Pichia pastoris for Solid-State NMR." Biomolecules 10, no. 3 (March 11, 2020): 434. http://dx.doi.org/10.3390/biom10030434.

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Solid-state nuclear magnetic resonance (SSNMR) is a powerful biophysical technique for studies of membrane proteins; it requires the incorporation of isotopic labels into the sample. This is usually accomplished through over-expression of the protein of interest in a prokaryotic or eukaryotic host in minimal media, wherein all (or some) carbon and nitrogen sources are isotopically labeled. In order to obtain multi-dimensional NMR spectra with adequate signal-to-noise ratios suitable for in-depth analysis, one requires high yields of homogeneously structured protein. Some membrane proteins, such as human aquaporin 2 (hAQP2), exhibit poor expression, which can make producing a sample for SSNMR in an economic fashion extremely difficult, as growth in minimal media adds additional strain on expression hosts. We have developed an optimized growth protocol for eukaryotic membrane proteins in the methylotrophic yeast Pichia pastoris. Our new growth protocol uses the combination of sorbitol supplementation, higher cell density, and low temperature induction (LT-SEVIN), which increases the yield of full-length, isotopically labeled hAQP2 ten-fold. Combining mass spectrometry and SSNMR, we were able to determine the nature and the extent of post-translational modifications of the protein. The resultant protein can be functionally reconstituted into lipids and yields excellent resolution and spectral coverage when analyzed by two-dimensional SSNMR spectroscopy.
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20

Hildebrand, Marcel, Hiyam Hamaed, Andrew M. Namespetra, John M. Donohue, Riqiang Fu, Ivan Hung, Zhehong Gan, and Robert W. Schurko. "35Cl solid-state NMR of HCl salts of active pharmaceutical ingredients: structural prediction, spectral fingerprinting and polymorph recognition." CrystEngComm 16, no. 31 (2014): 7334–56. http://dx.doi.org/10.1039/c4ce00544a.

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A series of HCl salts of active pharmaceutical ingredients (APIs) have been characterized via35Cl solid-state NMR (SSNMR) spectroscopy and first-principles plane-wave DFT calculations of 35Cl NMR interaction tensors.
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21

Weber, Daniel K., and Gianluigi Veglia. "A Theoretical Assessment of the Structure Determination of Multi-Span Membrane Proteins by Oriented Sample Solid-State NMR Spectroscopy." Australian Journal of Chemistry 73, no. 3 (2020): 246. http://dx.doi.org/10.1071/ch19307.

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Oriented sample solid-state NMR (OS-ssNMR) spectroscopy allows the direct determination of the structure and topology of membrane proteins reconstituted into aligned lipid bilayers. Although OS-ssNMR theoretically has no upper size limit, its application to multi-span membrane proteins has not been established because most studies have been restricted to single- or dual-span proteins and peptides. Here, we present a critical assessment of the application of this method to multi-span membrane proteins. We used molecular dynamics simulations to back-calculate [15N-1H] separated local field (SLF) spectra from a G protein-coupled receptor (GPCR) and show that fully resolved spectra can be obtained theoretically for a multi-span membrane protein with currently achievable resonance linewidths.
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22

Rodriguez-Gomez, Alberto, Abhishek Dutta Chowdhury, Mustafa Caglayan, Jeremy A. Bau, Edy Abou-Hamad, and Jorge Gascon. "Non-oxidative dehydrogenation of isobutane over supported vanadium oxide: nature of the active sites and coke formation." Catalysis Science & Technology 10, no. 18 (2020): 6139–51. http://dx.doi.org/10.1039/d0cy01174f.

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We combine Raman spectroscopy, EPR, XPS, temperature programmed reduction, XRD, 51V MAS ssNMR, TEM and N2-physisorption to unravel structure–activity relationships during the non-oxidative dehydrogenation of isobutane over a V based catalyst.
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23

Neary, Marianne T., David G. Reid, Matthew J. Mason, Tomislav Friščić, Melinda J. Duer, and Maggie Cusack. "Contrasts between organic participation in apatite biomineralization in brachiopod shell and vertebrate bone identified by nuclear magnetic resonance spectroscopy." Journal of The Royal Society Interface 8, no. 55 (July 7, 2010): 282–88. http://dx.doi.org/10.1098/rsif.2010.0238.

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Unusually for invertebrates, linguliform brachiopods employ calcium phosphate mineral in hard tissue formation, in common with the evolutionarily distant vertebrates. Using solid-state nuclear magnetic resonance spectroscopy (SSNMR) and X-ray powder diffraction, we compare the organic constitution, crystallinity and organic matrix–mineral interface of phosphatic brachiopod shells with those of vertebrate bone. In particular, the organic–mineral interfaces crucial for the stability and properties of biomineral were probed with SSNMR rotational echo double resonance (REDOR). Lingula anatina and Discinisca tenuis shell materials yield strikingly dissimilar SSNMR spectra, arguing for quite different organic constitutions. However, their fluoroapatite-like mineral is highly crystalline, unlike the poorly ordered hydroxyapatite of bone. Neither shell material shows 13 C{ 31 P} REDOR effects, excluding strong physico-chemical interactions between mineral and organic matrix, unlike bone in which glycosaminoglycans and proteins are composited with mineral at sub-nanometre length scales. Differences between organic matrix of shell material from L. anatina and D. tenuis , and bone reflect evolutionary pressures from contrasting habitats and structural purposes. The absence of organic–mineral intermolecular associations in brachiopod shell argues that biomineralization follows different mechanistic pathways to bone; their details hold clues to the molecular structural evolution of phosphatic biominerals, and may provide insights into novel composite design.
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Damman, Reinier, Alessandra Lucini Paioni, Katerina T. Xenaki, Irati Beltrán Hernández, Paul M. P. van Bergen en Henegouwen, and Marc Baldus. "Development of in vitro-grown spheroids as a 3D tumor model system for solid-state NMR spectroscopy." Journal of Biomolecular NMR 74, no. 8-9 (June 19, 2020): 401–12. http://dx.doi.org/10.1007/s10858-020-00328-8.

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Abstract Recent advances in the field of in-cell NMR spectroscopy have made it possible to study proteins in the context of bacterial or mammalian cell extracts or even entire cells. As most mammalian cells are part of a multi-cellular complex, there is a need to develop novel NMR approaches enabling the study of proteins within the complexity of a 3D cellular environment. Here we investigate the use of the hanging drop method to grow spheroids which are homogenous in size and shape as a model system to study solid tumors using solid-state NMR (ssNMR) spectroscopy. We find that these spheroids are stable under magic-angle-spinning conditions and show a clear change in metabolic profile as compared to single cell preparations. Finally, we utilize dynamic nuclear polarization (DNP)-supported ssNMR measurements to show that low concentrations of labelled nanobodies targeting EGFR (7D12) can be detected inside the spheroids. These findings suggest that solid-state NMR can be used to directly examine proteins or other biomolecules in a 3D cellular microenvironment with potential applications in pharmacological research.
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25

Czernek, Jiří, and Jiří Brus. "Monitoring the Site-Specific Solid-State NMR Data in Oligopeptides." International Journal of Molecular Sciences 21, no. 8 (April 13, 2020): 2700. http://dx.doi.org/10.3390/ijms21082700.

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Reliable values of the solid-state NMR (SSNMR) parameters together with precise structural data specific for a given amino acid site in an oligopeptide are needed for the proper interpretation of measurements aiming at an understanding of oligopeptides’ function. The periodic density functional theory (DFT)-based computations of geometries and SSNMR chemical shielding tensors (CSTs) of solids are shown to be accurate enough to support the SSNMR investigations of suitably chosen models of oriented samples of oligopeptides. This finding is based on a thorough comparison between the DFT and experimental data for a set of tripeptides with both 13Cα and 15Namid CSTs available from the single-crystal SSNMR measurements and covering the three most common secondary structural elements of polypeptides. Thus, the ground is laid for a quantitative description of local spectral parameters of crystalline oligopeptides, as demonstrated for the backbone 15Namid nuclei of samarosporin I, which is a pentadecapeptide (composed of five classical and ten nonproteinogenic amino acids) featuring a strong antimicrobial activity.
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Yamada, Shunji, Eisuke Chikayama, and Jun Kikuchi. "Signal Deconvolution and Generative Topographic Mapping Regression for Solid-State NMR of Multi-Component Materials." International Journal of Molecular Sciences 22, no. 3 (January 22, 2021): 1086. http://dx.doi.org/10.3390/ijms22031086.

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Solid-state nuclear magnetic resonance (ssNMR) spectroscopy provides information on native structures and the dynamics for predicting and designing the physical properties of multi-component solid materials. However, such an analysis is difficult because of the broad and overlapping spectra of these materials. Therefore, signal deconvolution and prediction are great challenges for their ssNMR analysis. We examined signal deconvolution methods using a short-time Fourier transform (STFT) and a non-negative tensor/matrix factorization (NTF, NMF), and methods for predicting NMR signals and physical properties using generative topographic mapping regression (GTMR). We demonstrated the applications for macromolecular samples involved in cellulose degradation, plastics, and microalgae such as Euglena gracilis. During cellulose degradation, 13C cross-polarization (CP)–magic angle spinning spectra were separated into signals of cellulose, proteins, and lipids by STFT and NTF. GTMR accurately predicted cellulose degradation for catabolic products such as acetate and CO2. Using these methods, the 1H anisotropic spectrum of poly-ε-caprolactone was separated into the signals of crystalline and amorphous solids. Forward prediction and inverse prediction of GTMR were used to compute STFT-processed NMR signals from the physical properties of polylactic acid. These signal deconvolution and prediction methods for ssNMR spectra of macromolecules can resolve the problem of overlapping spectra and support macromolecular characterization and material design.
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Aliyev, Elvin, Volkan Filiz, Muntazim M. Khan, Young Joo Lee, Clarissa Abetz, and Volker Abetz. "Structural Characterization of Graphene Oxide: Surface Functional Groups and Fractionated Oxidative Debris." Nanomaterials 9, no. 8 (August 18, 2019): 1180. http://dx.doi.org/10.3390/nano9081180.

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The purpose of this work is the structural analysis of graphene oxide (GO) and by means of a new structural model to answer the questions arising from the Lerf–Klinowski and the Lee structural models. Surface functional groups of GO layers and the oxidative debris (OD) stacked on them were investigated after OD was extracted. Analysis was performed successfully using Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-Vis), X-ray photoemission spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDX), Raman spectroscopy, solid-state nuclear magnetic resonance spectroscopy (SSNMR), standardized Boehm potentiometric titration analysis, elemental analysis, X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The analysis showed that graphene oxide layers, as well as oxidative debris contain different functional groups such as phenolic –OH, ketone, lactone, carboxyl, quinone and epoxy. Based on these results, a new structural model for GO layers is proposed, which covers all spectroscopic data and explains the presence of the other oxygen functionalities besides carboxyl, phenolic –OH and epoxy groups.
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Brus, J., J. Czernek, M. Urbanova, L. Kobera, and A. Jegorov. "An efficient 2D 11B–11B solid-state NMR spectroscopy strategy for monitoring covalent self-assembly of boronic acid-derived compounds: the transformation and unique architecture of bortezomib molecules in the solid state." Physical Chemistry Chemical Physics 19, no. 1 (2017): 487–95. http://dx.doi.org/10.1039/c6cp06555d.

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Stevens, Joanna, Stephen Byard, Colin Seaton, Ghazala Sadiq, Roger Davey, and Sven Schroeder. "H-bonds and Protons in Molecular Crystals: Insight from Combined XPS/ssNMR/XRD." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C531. http://dx.doi.org/10.1107/s2053273314094686.

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Physicochemical properties of molecular crystals are significantly influenced by non-covalent interactions and proton transfer. A well known application is the tuning of solubility, bioavailability and stability of pharmaceutical actives through co-crystal (hydrogen-bonding) or salt (ionic, Brønsted acceptors) formation. X-ray Photoelectron Spectroscopy (XPS) is an intrinsically local structural probe, providing information on the chemical state and chemical environment of atoms in molecules and crystals through the photoemission of core level electrons. We have recently studied a wide range of acid-base complexes in molecular crystals and found that analyzing the chemical shifts of N1s core level binding energies provides a facile route for characterizing the chemical and structural changes at functional groups involved in hydrogen bonding and proton transfer [1]. Very importantly, XPS unequivocally distinguishes protonated (salt) from hydrogen-bonded (co-crystal) nitrogen moieties. We have complemented our results for nitrogen species with 15N Solid-State Nuclear Magnetic Resonance (ssNMR) chemical shifts, which reveal low frequency shifts with protonation, but the magnitude of these shifts is additionally influenced by the wider chemical environment [2]. When crystallographic structure information is available, ssNMR shifts can be computationally predicted and thereby related to H-bond lengths, giving a measure of H-bond strength (NMR crystallography). The wide variety of donor/acceptor systems we have investigated has covered a large range of pKa values and demonstrates the generic nature of taking an XPS/ssNMR/XRD approach to organic molecule crystallography (Fig 1). The excellent agreement between the conclusions drawn by XPS and combined ssNMR/CASTEP investigations opens up a reliable avenue for local structure characterization in molecular systems even in the absence of crystal structure information, for example with non-crystalline or amorphous matter.
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le Paige, Ulric B., ShengQi Xiang, Marco M. R. M. Hendrix, Yi Zhang, Gert E. Folkers, Markus Weingarth, Alexandre M. J. J. Bonvin, et al. "Characterization of nucleosome sediments for protein interaction studies by solid-state NMR spectroscopy." Magnetic Resonance 2, no. 1 (April 21, 2021): 187–202. http://dx.doi.org/10.5194/mr-2-187-2021.

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Abstract. Regulation of DNA-templated processes such as gene transcription and DNA repair depend on the interaction of a wide range of proteins with the nucleosome, the fundamental building block of chromatin. Both solution and solid-state NMR spectroscopy have become an attractive approach to study the dynamics and interactions of nucleosomes, despite their high molecular weight of ∼200 kDa. For solid-state NMR (ssNMR) studies, dilute solutions of nucleosomes are converted to a dense phase by sedimentation or precipitation. Since nucleosomes are known to self-associate, these dense phases may induce extensive interactions between nucleosomes, which could interfere with protein-binding studies. Here, we characterized the packing of nucleosomes in the dense phase created by sedimentation using NMR and small-angle X-ray scattering (SAXS) experiments. We found that nucleosome sediments are gels with variable degrees of solidity, have nucleosome concentration close to that found in crystals, and are stable for weeks under high-speed magic angle spinning (MAS). Furthermore, SAXS data recorded on recovered sediments indicate that there is no pronounced long-range ordering of nucleosomes in the sediment. Finally, we show that the sedimentation approach can also be used to study low-affinity protein interactions with the nucleosome. Together, our results give new insights into the sample characteristics of nucleosome sediments for ssNMR studies and illustrate the broad applicability of sedimentation-based NMR studies.
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Denny, J. K., M. B. Daniel, and F. A. Kovacs. "Computing and fitting SSNMR powder patterns with the arithmetic-geometric mean and edge detection." Concepts in Magnetic Resonance Part A 30A, no. 1 (January 2007): 1–20. http://dx.doi.org/10.1002/cmr.a.20073.

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Czernek, Jiří, and Jiří Brus. "Polymorphic Forms of Valinomycin Investigated by NMR Crystallography." International Journal of Molecular Sciences 21, no. 14 (July 11, 2020): 4907. http://dx.doi.org/10.3390/ijms21144907.

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A dodecadepsipeptide valinomycin (VLM) has been most recently reported to be a potential anti-coronavirus drug that could be efficiently produced on a large scale. It is thus of importance to study solid-phase forms of VLM in order to be able to ensure its polymorphic purity in drug formulations. The previously available solid-state NMR (SSNMR) data are combined with the plane-wave DFT computations in the NMR crystallography framework. Structural/spectroscopical predictions (the PBE functional/GIPAW method) are obtained to characterize four polymorphs of VLM. Interactions which confer a conformational stability to VLM molecules in these crystalline forms are described in detail. The way how various structural factors affect the values of SSNMR parameters is thoroughly analyzed, and several SSNMR markers of the respective VLM polymorphs are identified. The markers are connected to hydrogen bonding effects upon the corresponding (13C/15N/1H) isotropic chemical shifts of (CO, Namid, Hamid, Hα) VLM backbone nuclei. These results are expected to be crucial for polymorph control of VLM and in probing its interactions in dosage forms.
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Fricke, Pascal, Jean-Philippe Demers, Stefan Becker, and Adam Lange. "Studies on the MxiH Protein in T3SS Needles Using DNP-Enhanced ssNMR Spectroscopy." ChemPhysChem 15, no. 1 (November 26, 2013): 57–60. http://dx.doi.org/10.1002/cphc.201300994.

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34

Jurczak, Ewa, Anna Helena Mazurek, Łukasz Szeleszczuk, Dariusz Maciej Pisklak, and Monika Zielińska-Pisklak. "Pharmaceutical Hydrates Analysis—Overview of Methods and Recent Advances." Pharmaceutics 12, no. 10 (October 11, 2020): 959. http://dx.doi.org/10.3390/pharmaceutics12100959.

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This review discusses a set of instrumental and computational methods that are used to characterize hydrated forms of APIs (active pharmaceutical ingredients). The focus has been put on highlighting advantages as well as on presenting some limitations of the selected analytical approaches. This has been performed in order to facilitate the choice of an appropriate method depending on the type of the structural feature that is to be analyzed, that is, degree of hydration, crystal structure and dynamics, and (de)hydration kinetics. The presented techniques include X-ray diffraction (single crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD)), spectroscopic (solid state nuclear magnetic resonance spectroscopy (ssNMR), Fourier-transformed infrared spectroscopy (FT-IR), Raman spectroscopy), thermal (differential scanning calorimetry (DSC), thermogravimetric analysis (TGA)), gravimetric (dynamic vapour sorption (DVS)), and computational (molecular mechanics (MM), Quantum Mechanics (QM), molecular dynamics (MD)) methods. Further, the successful applications of the presented methods in the studies of hydrated APIs as well as studies on the excipients’ influence on these processes have been described in many examples.
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35

Saliba, Daniel, and Mazen Al-Ghoul. "Kinetics of intercalation of fluorescent probes in magnesium–aluminium layered double hydroxide within a multiscale reaction–diffusion framework." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 374, no. 2080 (November 13, 2016): 20160138. http://dx.doi.org/10.1098/rsta.2016.0138.

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We report the synthesis of magnesium–aluminium layered double hydroxide (LDH) using a reaction–diffusion framework (RDF) that exploits the multiscale coupling of molecular diffusion with chemical reactions, nucleation and growth of crystals. In an RDF, the hydroxide anions are allowed to diffuse into an organic gel matrix containing the salt mixture needed for the precipitation of the LDH. The chemical structure and composition of the synthesized magnesium–aluminium LDHs are determined using powder X-ray diffraction (PXRD), thermo-gravimetric analysis, differential scanning calorimetry, solid-state nuclear magnetic resonance (SSNMR), Fourier transform infrared and energy dispersive X-ray spectroscopy. This novel technique also allows the investigation of the mechanism of intercalation of some fluorescent probes, such as the neutral three-dimensional rhodamine B (RhB) and the negatively charged two-dimensional 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS), using in situ steady-state fluorescence spectroscopy. The incorporation of these organic dyes inside the interlayer region of the LDH is confirmed via fluorescence microscopy, solid-state lifetime, SSNMR and PXRD. The activation energies of intercalation of the corresponding molecules (RhB and HPTS) are computed and exhibit dependence on the geometry of the involved probe (two or three dimensions), the charge of the fluorescent molecule (anionic, cationic or neutral) and the cationic ratio of the corresponding LDH. This article is part of the themed issue ‘Multiscale modelling at the physics–chemistry–biology interface’.
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36

Czernek, Jiří, and Jiří Brus. "Modeling the Structure of Crystalline Alamethicin and Its NMR Chemical Shift Tensors." Antibiotics 10, no. 10 (October 18, 2021): 1265. http://dx.doi.org/10.3390/antibiotics10101265.

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Alamethicin (ALM) is an antimicrobial peptide that is frequently employed in studies of the mechanism of action of pore-forming molecules. Advanced techniques of solid-state NMR spectroscopy (SSNMR) are important in these studies, as they are capable of describing the alignment of helical peptides, such as ALM, in lipid bilayers. Here, it is demonstrated how an analysis of the SSNMR measurements can benefit from fully periodic calculations, which employ the plane-wave density-functional theory (PW DFT) of the solid-phase geometry and related spectral parameters of ALM. The PW DFT calculations are used to obtain the structure of desolvated crystalline ALM and predict the NMR chemical shift tensors (CSTs) of its nuclei. A variation in the CSTs of the amidic nitrogens and carbonyl carbons along the ALM backbone is evaluated and included in simulations of the orientation-dependent anisotropic 15N and 13C chemical shift components. In this way, the influence of the site-specific structural effects on the experimentally determined orientation of ALM is shown in models of cell membranes.
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37

Cheng, Qinghui, Zhi-Wen Hu, Yuto Tobin-Miyaji, Amy E. Perkins, Terrence Deak, and Wei Qiang. "Fibrillization of 40-residue β-Amyloid Peptides in Membrane-Like Environments Leads to Different Fibril Structures and Reduced Molecular Polymorphisms." Biomolecules 10, no. 6 (June 8, 2020): 881. http://dx.doi.org/10.3390/biom10060881.

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The molecular-level polymorphism in β-Amyloid (Aβ) fibrils have recently been considered as a pathologically relevant factor in Alzheimer’s disease (AD). Studies showed that the structural deviations in human-brain-seeded Aβ fibrils potentially correlated with the clinical histories of AD patients. For the 40-residue Aβ (Aβ40) fibrils derived from human brain tissues, a predominant molecular structure was proposed based on solid-state nuclear magnetic resonance (ssNMR) spectroscopy. However, previous studies have shown that the molecular structures of Aβ40 fibrils were sensitive to their growth conditions in aqueous environments. We show in this work that biological membranes and their phospholipid bilayer mimics serve as environmental factors to reduce the structural heterogeneity in Aβ40 fibrils. Fibrillization in the presence of membranes leads to fibril structures that are significantly different to the Aβ40 fibrils grown in aqueous solutions. Fibrils grown from multiple types of membranes, including the biological membranes extracted from the rats’ synaptosomes, shared similar ssNMR spectral features. Our studies emphasize the biological relevance of membranes in Aβ40 fibril structures and fibrillization processes.
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Qian, Jianying, Xiaomeng Wang, Jie Shu, Chang Su, Jinsong Gong, Zhenghong Xu, Jian Jin, and Jinsong Shi. "A Novel Complex of Chitosan–Sodium Carbonate and Its Properties." Marine Drugs 16, no. 11 (October 30, 2018): 416. http://dx.doi.org/10.3390/md16110416.

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Chitosan has excellent properties, as it is nontoxic, mucoadhesive, biocompatible, and biodegradable. However, the poor water solubility of chitosan is a major disadvantage. Here, a novel chitosan-sodium carbonate complex was formed by adding a large amount of sodium carbonate to a chitosan/acetic acid solution, which is water-soluble. Fourier transform infrared spectroscopy, energy dispersive spectrometry, scanning electron microscopy, and solid-state nuclear magnetic resonance techniques were used to detect and characterize the aforementioned complex, which appeared to be a neat flake crystal. Solid-state nuclear magnetic resonance (SSNMR) was used to verify the connections between carbonate, sodium ions, and the protonated amino group in chitosan on the basis of 13C signals at the chemical shift of 167.745 ppm and 164.743 ppm. Further confirmation was provided by the strong cross-polarization signals identified by the SSNMR 2D 13C–1H frequency-switched Lee–Goldberg heteronuclear correlation spectrum. The cytotoxicity of a film prepared using this complex was tested using rat fibroblasts. The results show that the film promoted cell proliferation, which provides evidence to support its nontoxicity. The ease of film-forming and the results of cytocompatibility testing suggest that the chitosan-sodium carbonate complex has the potential for use in tissue engineering.
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39

Oliveira, Filipa M., Teresa G. Nunes, Nadya V. Dencheva, and Zlatan Z. Denchev. "Structure and Molecular Dynamics in Metal-Containing Polyamide 6 Microparticles." Crystals 12, no. 11 (November 5, 2022): 1579. http://dx.doi.org/10.3390/cryst12111579.

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Polymer microparticles are used in additive manufacturing, separation and purification devices, biocatalysis, or for the recognition of biomolecules. This study reports on the effect of metal fillers on the structure and molecular dynamics of polyamide 6 (PA6) microparticles (MPs) containing up to 19 wt.% of Al, Cu, or Mg. These hybrid MPs are synthesized via reactive microencapsulation by anionic ring-opening polymerization in solution, in the presence of the metal filler. 13C high-resolution solid-state NMR (ssNMR) spectroscopy is employed as the primary characterization method using magic angle spinning (MAS) and cross-polarization (CP)/MAS. Depending on the metal filler, the ssNMR crystallinity index of the MP varies between 39–50%, as determined by deconvolution of the 13C MAS and CP/MAS spectra. These values correlate very well with the crystallinity derived from thermal or X-ray diffraction data. The molecular dynamics study on PA6 and Cu-containing MP shows similar mobility of carbon nuclei in the kHz, but not in the MHz frequency ranges. The paramagnetic Al and Mg have an observable effect on the relaxation; however, conclusions regarding the PA6 carbon motions cannot be unequivocally made. These results are useful in the preparation of hybrid microparticles with customized structures and magneto-electrical properties.
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40

Porcino, Marianna, Xue Li, Ruxandra Gref, and Charlotte Martineau-Corcos. "Solid-State NMR Spectroscopy: A Key Tool to Unravel the Supramolecular Structure of Drug Delivery Systems." Molecules 26, no. 14 (July 7, 2021): 4142. http://dx.doi.org/10.3390/molecules26144142.

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In the past decades, nanosized drug delivery systems (DDS) have been extensively developed and studied as a promising way to improve the performance of a drug and reduce its undesirable side effects. DDSs are usually very complex supramolecular assemblies made of a core that contains the active substance(s) and ensures a controlled release, which is surrounded by a corona that stabilizes the particles and ensures the delivery to the targeted cells. To optimize the design of engineered DDSs, it is essential to gain a comprehensive understanding of these core–shell assemblies at the atomic level. In this review, we illustrate how solid-state nuclear magnetic resonance (ssNMR) spectroscopy has become an essential tool in DDS design.
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41

Haber, Shira, Rosy, Arka Saha, Olga Brontvein, Raanan Carmieli, Arava Zohar, Malachi Noked, and Michal Leskes. "Structure and Functionality of an Alkylated LixSiyOz Interphase for High-Energy Cathodes from DNP-ssNMR Spectroscopy." Journal of the American Chemical Society 143, no. 12 (March 22, 2021): 4694–704. http://dx.doi.org/10.1021/jacs.1c00215.

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42

Levchenko, Tetyana I., Bryan E. G. Lucier, John F. Corrigan, and Yining Huang. "Crystalline Superlattices of Nanoscopic CdS Molecular Clusters: An X-ray Crystallography and 111Cd SSNMR Spectroscopy Study." Inorganic Chemistry 57, no. 1 (December 15, 2017): 204–17. http://dx.doi.org/10.1021/acs.inorgchem.7b02403.

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43

Rodríguez, Andrés, Elio Rico, Cesar Sierra, and Oscar Rodríguez. "Impedimetric Detection of Ammonia and Low Molecular Weight Amines in the Gas Phase with Covalent Organic Frameworks." Sensors 20, no. 5 (March 3, 2020): 1385. http://dx.doi.org/10.3390/s20051385.

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Two Covalent Organic Frameworks (COF), named TFP-BZ and TFP-DMBZ, were synthesized using the imine condensation between 1,3,5-triformylphloroglucinol (TFP) with benzidine (BZ) or 3,3-dimethylbenzidine (DMBZ). These materials were deposited, such as films over interdigitated electrodes (IDE), by chemical bath deposition, giving rise to TFP-BZ-IDE and TFP-DMBZ-IDE systems. The synthesized COFs powders were characterized by Powder X-Ray Diffraction (PXRD), Fourier Transform Infrared spectroscopy (FT-IR), solid-state Nuclear Magnetic Resonance (ssNMR), nitrogen adsorption isotherms, Scanning Electron Microscopy (SEM), and Raman spectroscopy, while the films were characterized by SEM and Raman. Ammonia and low molecular weight amine sensing were developed with the COF film systems using the impedance electrochemical spectroscopy (EIS). Results showed that the systems TFP-BZ-IDE and TFP-DMBZ-IDE detect low molecular weight amines selectively by impedimetric analysis. Remarkably, with no significant interference by other atmospheric gas compounds such as nitrogen, carbon dioxide, and methane. Additionally, both COF films presented a range of sensitivity at low amine concentrations below two ppm at room temperature.
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44

Leroy, Cesar, Thomas-Xavier Métro, and Danielle Laurencin. "Exploring zinc terephthalate complexes through multinuclear ssNMR and in situ reaction monitoring by Raman spectroscopy." Acta Crystallographica Section A Foundations and Advances 77, a2 (August 14, 2021): C1101. http://dx.doi.org/10.1107/s0108767321086037.

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45

Crowley, Kieran J., Robert T. Forbes, Peter York, David C. Apperley, Håkan Nyqvist, and Ola Camber. "Characterization of Oleic Acid and Propranolol Oleate Mesomorphism using 13C Solid‐State Nuclear Magnetic Resonance Spectroscopy (SSNMR)." Journal of Pharmaceutical Sciences 89, no. 10 (October 2000): 1286–95. http://dx.doi.org/10.1002/1520-6017(200010)89:10<1286::aid-jps6>3.0.co;2-o.

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46

Zhang, Jing, Jian Wang, Chengwei Ma, and Junxia Lu. "Hydroxyapatite Formation Coexists with Amyloid-like Self-Assembly of Human Amelogenin." International Journal of Molecular Sciences 21, no. 8 (April 22, 2020): 2946. http://dx.doi.org/10.3390/ijms21082946.

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Tooth enamel is formed in an extracellular environment. Amelogenin, the major component in the protein matrix of tooth enamel during the developing stage, could assemble into high molecular weight structures, regulating enamel formation. However, the molecular structure of amelogenin protein assembly at the functional state is still elusive. In this work, we found that amelogenin is able to induce calcium phosphate minerals into hydroxyapatite (HAP) structure in vitro at pH 6.0. Assessed using X-ray diffraction (XRD) and 31P solid-state NMR (SSNMR) evidence, the formed HAP mimics natural enamel closely. The structure of amelogenin protein assembly coexisting with the HAP was also studied using atomic force microscopy (AFM), transmission electron microscopy (TEM) and XRD, indicating the β-amyloid structure of the protein. SSNMR was proven to be an important tool in detecting both the rigid and dynamic components of the protein assembly in the sample, and the core sequence 18EVLTPLKWYQSI29 was identified as the major segment contributing to the β-sheet secondary structure. Our research suggests an amyloid structure may be an important factor in controlling HAP formation at the right pH conditions with the help of other structural components in the protein assembly.
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47

Suzuki, Katsuaki, and Hironori Kaji. "(Invited) Structural Analysis of Organic Semiconducting Materials By Solid State NMR." ECS Meeting Abstracts MA2022-01, no. 13 (July 7, 2022): 910. http://dx.doi.org/10.1149/ma2022-0113910mtgabs.

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Recently, our group have successfully developed several blue and green thermally activated delayed fluorescence (TADF) emitters showing high external quantum efficiencies in OLEDs through high-throughput screening based on quantum chemical calculations. Although a number of highly efficient TADF emitters have been reported, the study about their conformation and aggregated structure in an amorphous states, which is expected to be the origin of high device performance, is still limited. Thus we have carried out multiscale simulations and solid-state NMR (ssNMR) analysis of organic amorphous thin films. The ssNMR is one of the powerful technique to acquire the structural information of amorphous aggregated materials, which has been difficult by diffraction techniques due to the lack of long range order for amorphous state. In this presentation, we demonstrate ssNMR analysis of amorphous organic semiconducting materials. Reference (1) “Analysis of Molecular Orientation in Organic Semiconducting Thin Films Using Static Dynamic Nuclear Polarization Enhanced Solid-State NMR Spectroscopy”, Suzuki, K.; Kubo, S.; Aussenac, F.; Engelke, F.; Fukushima, T.; Kaji, H. Angew. Chem. Int. Ed. 2017, 56, 14842. (2) “Efficient blue thermally activated delayed fluorescence emitters showing very fast reverse intersystem crossing”, Ren, Y., Wada, Y., Suzuki, K., Kusakabe, Y., Geldsetzer, J. and Kaji, H. Appl. Phys. Express, 2021, 14, 071003. (3) “Solution-processable thermally activated delayed fluorescence emitters for application in organic light emitting diodes”, Suzuki, K.; Adachi, C.; Kaji, H. J. Soc. Inf. Disp. 2017, 25, 480. (4) “Combined Inter- and Intramolecular Charge-Transfer Processes for Highly Efficient Fluorescent Organic Light-Emitting Diodes with Reduced Triplet Exciton Quenching”, Moon, C.-K.; Suzuki, K.; Shizu, K.; Adachi, C.; Kaji, H.; Kim, J.-J. Adv. Mater. 2017, 131, 6614. (5) “Triarylboron-based Fluorescent Organic Light-emitting Diodes with External Quantum Efficiencies Exceeding 20%”, Suzuki, K.; Kubo, S.; Shizu, K.; Fukushima, T.; Wakamiya, A.; Murata, Y.; Adachi, C.; Kaji, H.; Angew. Chem. Int. Ed. 2015, 54, 15231. (5) “Purely organic electroluminescent material realizing 100% conversion from electricity to light”, Kaji, H.; Suzuki, H.; Fukushima, T.; Shizu, K.; Suzuki, K.; Kubo, S.; Komino, T.; Oiwa, H.; Suzuki, F.; Wakamiya, A.; Murata, Y.; Adachi, C. Nat. Commun. 2015, 6, 8476.
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48

Peklar, Boris, Franc Perdih, Damjan Makuc, Janez Plavec, Jérôme Cluzeau, Zoran Kitanovski, and Zdenko Časar. "Glasdegib Dimaleate: Synthesis, Characterization and Comparison of Its Properties with Monomaleate Analogue." Pharmaceutics 14, no. 8 (August 6, 2022): 1641. http://dx.doi.org/10.3390/pharmaceutics14081641.

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Glasdegib is a recently approved drug for the treatment of acute myeloid leukemia. It is formulated and marketed in monomaleate salt form. In our investigation, we were able to prepare a glasdegib dimaleate form, which could, in theory, exist in double-salt form or as a mixture of salt and co-crystal species. Therefore, the obtained crystals of glasdegib dimaleate were characterized via 15N ssNMR and single-crystal X-ray diffraction, which revealed that the obtained glasdegib dimaleate exists in double-salt form. This is a surprising finding based on the pKa values for glasdegib and maleic acid. Furthermore, we fully characterized the new dimaleate form using thermal analyses (DSC and TGA) and spectroscopy (IR and Raman). Finally, the physicochemical properties, such as solubility and chemical stability, of both forms were determined and compared.
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49

Gago, Diana, Marta C. Corvo, Ricardo Chagas, Luísa M. Ferreira, and Isabel Coelhoso. "Protein Adsorption Performance of a Novel Functionalized Cellulose-Based Polymer." Polymers 14, no. 23 (November 24, 2022): 5122. http://dx.doi.org/10.3390/polym14235122.

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Dicarboxymethyl cellulose (DCMC) was synthesized and tested for protein adsorption. The prepared polymer was characterized by inductively coupled plasma atomic emission spectrometry (ICP-AES), attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) and solid state nuclear magnetic resonance (ssNMR) to confirm the functionalization of cellulose. This work shows that protein adsorption onto DCMC is charge dependent. The polymer adsorbs positively charged proteins, cytochrome C and lysozyme, with adsorption capacities of 851 and 571 mg g−1, respectively. In both experiments, the adsorption process follows the Langmuir adsorption isotherm. The adsorption kinetics by DCMC is well described by the pseudo second-order model, and adsorption equilibrium was reached within 90 min. Moreover, DCMC was successfully reused for five consecutive adsorption–desorption cycles, without compromising the removal efficiency (98–99%).
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50

Li, Xue, Marianna Porcino, Jingwen Qiu, Doru Constantin, Charlotte Martineau-Corcos, and Ruxandra Gref. "Doxorubicin-Loaded Metal-Organic Frameworks Nanoparticles with Engineered Cyclodextrin Coatings: Insights on Drug Location by Solid State NMR Spectroscopy." Nanomaterials 11, no. 4 (April 8, 2021): 945. http://dx.doi.org/10.3390/nano11040945.

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Recently developed, nanoscale metal-organic frameworks (nanoMOFs) functionalized with versatile coatings are drawing special attention in the nanomedicine field. Here we show the preparation of core–shell MIL-100(Al) nanoMOFs for the delivery of the anticancer drug doxorubicin (DOX). DOX was efficiently incorporated in the MOFs and was released in a progressive manner, depending on the initial loading. Besides, the coatings were made of biodegradable γ-cyclodextrin-citrate oligomers (CD-CO) with affinity for both DOX and the MOF cores. DOX was incorporated and released faster due to its affinity for the coating material. A set of complementary solid state nuclear magnetic resonance (ssNMR) experiments including 1H-1H and 13C-27Al two-dimensional NMR, was used to gain a deep understanding on the multiple interactions involved in the MIL-100(Al) core–shell system. To do so, 13C-labelled shells were synthesized. This study paves the way towards a methodology to assess the nanoMOF component localization at a molecular scale and to investigate the nanoMOF physicochemical properties, which play a main role on their biological applications.
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