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https://www.readbyqxmd.com/read/28722224/integrating-high-resolution-and-solid-state-magic-angle-spinning-nmr-spectroscopy-and-a-transcriptomic-analysis-of-soybean-tissues-in-response-to-water-deficiency
#1
Isabel D Coutinho, Tiago Bueno Moraes, Liliane Marcia Mertz-Henning, Alexandre Lima Nepomuceno, Willian Giordani, Juliana Marcolino-Gomes, Silvia Santagneli, Luiz Alberto Colnago
INTRODUCTION: Solid-state NMR (SSNMR) spectroscopy methods provide chemical environment and ultrastructural details that are not easily accessible by other non-destructive, high-resolution spectral techniques. High-resolution magic angle spinning (HR-MAS) has been widely used to obtain the metabolic profile of a heterogeneous sample, combining the resolution enhancement provided by MAS in SSNMR with the shimming and locking procedures in liquid-state NMR. OBJECTIVE: In this work, we explored the feasibility of using the HR-MAS and SSNMR techniques to identify metabolic changes in soybean leaves subjected to water-deficient conditions...
July 19, 2017: Phytochemical Analysis: PCA
https://www.readbyqxmd.com/read/28697887/molecular-origins-of-the-compatibility-between-glycosaminoglycans-and-a%C3%AE-40-amyloid-fibrils
#2
Katie L Stewart, Eleri Hughes, Edwin A Yates, David A Middleton, Sheena E Radford
The Aβ peptide forms extracellular plaques associated with Alzheimer's disease. In addition to protein fibrils, amyloid plaques also contain non-proteinaceous components, including glycosaminoglycans (GAGs). We have shown previously that the GAG low molecular weight heparin (LMWH) binds to Aβ40 fibrils with a three-fold-symmetric (3Q) morphology with higher affinity than Aβ40 fibrils in alternative structures, Aβ42 fibrils, or amyloid fibrils formed from other sequences. Solid-state NMR (SSNMR) analysis of the GAG-3Q fibril complex revealed an interaction site at the corners of the 3Q fibril structure, but the origin of the binding specificity remained obscure...
July 8, 2017: Journal of Molecular Biology
https://www.readbyqxmd.com/read/28680037/sulfonated-reduced-graphene-oxide-catalyzed-cyclization-of-hydrazides-and-carbon-dioxide-to-1-3-4-oxadiazoles-under-sonication
#3
Manuri Brahmayya, Shenghong A Dai, Shing-Yi Suen
Acid catalysts facilitate many chemical reactions. Sulfonated reduced grapheneoxide (rGOPhSO3H) has shown to be an encouraging solid acid catalyst because of its efficiency, cost-effectiveness and safety of use. In this study, we prepared the rGOPhSO3H nano acid catalyst, with the introduction of aromatic sulfonic acid radicals onto GO by fractional removal of oxygenated functions. It was thoroughly characterized by FT-IR, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, energy dispersive spectroscopy (EDS) and solid state (13)C MAS NMR (SSNMR)...
July 5, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28663085/spectroscopic-and-structural-studies-of-the-diosmin-monohydrate-and-anhydrous-diosmin
#4
Łukasz Szeleszczuk, Dariusz Maciej Pisklak, Monika Zielińska-Pisklak, Iwona Wawer
Diosmin, a flavone glycoside frequently used in therapy of various veins diseases in monohydrate form, exhibits poor solubility in water and low bioavailability. Due to the fact that the anhydrous forms of drugs generally have better bioavailability than the corresponding hydrates, the aim of this study was to analyze the conversion of diosmin monohydrate (DSNM) to anhydrous diosmin (DSNA) that occurs upon heating. The mechanism of this transformation was examined as well as advanced structural studies of each form were performed using 13C CP/MAS SSNMR, DSC, FT-IR and PXRD techniques...
June 27, 2017: International Journal of Pharmaceutics
https://www.readbyqxmd.com/read/28657685/proton-in-a-confined-space-h-%C3%AF-crypt-111-iodide-and-some-of-its-halogen-bonded-derivatives
#5
Vijith Kumar, Tullio Pilati, Silvio Quici, Michele Remo Chierotti, Carlo Nervi, Roberto Gobetto, Giuseppe Resnati
Some experimental observations and theoretical calculations are reported on the structural features, in the solid, of crypt-111∙HI 1 and the three-component co-crystals that it forms with ,-diiodoperfluoroalkanes 2a-d. X-ray analyses indicate that, in all the five systems, the caged proton is, at low temperature, covalently bonded to a single nitrogen atom and is involved in a net of intramolecular hydrogen bonds. In contrast, 15N SSNMR at room temperature points to the magnetic equivalency of the two N atoms of crypt-111 in both 1 and its co-crystals with diiodoperfluoroalkanes...
June 28, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28655279/solid-state-deuterium-nmr-study-of-lk%C3%AE-14-peptide-aggregation-in-biosilica
#6
Helen E Ferreira, Gary P Drobny
In nature, organisms including diatoms, radiolaria, and marine sponges use proteins, long chain polyamines, and other organic molecules to regulate the assembly of complex silica-based structures. Here, the authors investigate structural features of small peptides, designed to mimic the silicifying activities of larger proteins found in natural systems. LKα14 (Ac-LKKLLKLLKKLLKL-C), an amphiphilic lysine/leucine repeat peptide with an α-helical secondary structure at polar/apolar interfaces, coprecipitates with silica to form nanospheres...
June 27, 2017: Biointerphases
https://www.readbyqxmd.com/read/28636347/structure-and-dynamics-of-alginate-gels-cross-linked-by-polyvalent-ions-probed-via-solid-state-nmr-spectroscopy
#7
Jiri Brus, Martina Urbanova, Jiri Czernek, Miroslava Pavelkova, Katerina Kubova, Jakub Vyslouzil, Sabina Abbrent, Rafal Konefal, Jiri Horský, David Vetchy, Jan Vysloužil, Pavel Kulich
Alginate gels are an outstanding biomaterial widely applicable in tissue engineering, medicine, and pharmacy for cell transplantation, wound healing and efficient bioactive agent delivery, respectively. This contribution provides new and comprehensive insight into the atomic-resolution structure and dynamics of polyvalent ion-cross-linked alginate gels in microbead formulations. By applying various advanced solid-state NMR (ssNMR) spectroscopy techniques, we verified the homogeneous distribution of the cross-linking ions in the alginate gels and the high degree of ion exchange...
July 3, 2017: Biomacromolecules
https://www.readbyqxmd.com/read/28636046/lead-ii-soaps-crystal-structures-polymorphism-and-solid-and-liquid-mesophases
#8
F J Martínez-Casado, M Ramos-Riesco, J A Rodríguez-Cheda, M I Redondo-Yélamos, L Garrido, A Fernández-Martínez, J García-Barriocanal, I da Silva, M Durán-Olivencia, A Poulain
The long-chain members of the lead(ii) alkanoate series or soaps, from octanoate to octadecanoate, have been thoroughly characterized by means of XRD, PDF analysis, DSC, FTIR, ssNMR and other techniques, in all their phases and mesophases. The crystal structures at room temperature of all of the members of the series are now solved, showing the existence of two polymorphic forms in the room temperature crystal phase, different to short and long-chain members. Only nonanoate and decanoate present both forms, and this polymorphism is proven to be monotropic...
June 21, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28629063/substitution-of-strontium-and-boron-into-hydroxyapatite-crystals-effect-on-physicochemical-properties-and-biocompatibility-with-human-wharton-jelly-stem-cells
#9
Joanna Kolmas, Frédéric Velard, Aneta Jaguszewska, Flora Lemaire, Halima Kerdjoudj, Sophie C Gangloff, Agnieszka Kaflak
Hydroxyapatite (HA) enriched with strontium and boron ions was synthesized using two different methods: the precipitation method (Sr,B-HAw) and the dry method (Sr,B-HAd). Additionally, for the sake of comparison, the "pure" unsubstituted HA was prepared together with HAs substituted only with one type of a foreign ion. The obtained materials were subjected to physicochemical analysis with the use of various analytical methods, such as powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), inductively coupled plasma optical emission spectroscopy (ICP-OES), Fourier transform infrared spectroscopy (FT-IR) and solid-state proton nuclear magnetic resonance ((1)H ssNMR)...
October 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28623473/increasing-the-bile-acid-sequestration-performance-of-cationic-hydrogels-by-using-an-advanced-controlled-polymerization-technique
#10
Patrícia V Mendonça, André Matos, Andreia F Sousa, Arménio C Serra, Sérgio Simões, Jorge F J Coelho
PURPOSE: To investigate the influence of the polymerization technique and the content of hydroxyl groups on the performance of new bile acid sequestrants based on PAMPMTA-co-PHEA (PAMPTMA: poly((3-acrylamidopropyl)trimethylammonium chloride); PHEA: poly(2-hydroxyethyl acrylate)) hydrogels. METHODS: PAMPMTA-co-PHEA hydrogels were prepared using either free radical polymerization or supplemental activator and reducing agent atom transfer radical polymerization. The chemical structure and composition of the hydrogels was confirmed by both FTIR and ssNMR...
June 16, 2017: Pharmaceutical Research
https://www.readbyqxmd.com/read/28621371/does-z-equal-1-or-2-enhanced-powder-nmr-crystallography-verification-of-a-disordered-room-temperature-crystal-structure-of-a-p38-inhibitor-for-chronic-obstructive-pulmonary-disease
#11
Cory M Widdifield, Sten O Nilsson Lill, Anders Broo, Maria Lindkvist, Anna Pettersen, Anna Svensk Ankarberg, Peter Aldred, Staffan Schantz, Lyndon Emsley
The crystal structure of the Form A polymorph of N-cyclopropyl-3-fluoro-4-methyl-5-[3-[[1-[2-[2-(methylamino)ethoxy]phenyl]cyclopropyl]amino]-2-oxo-pyrazin-1-yl]benzamide (i.e., AZD7624), determined using single-crystal X-ray diffraction (scXRD) at 100 K, contains two molecules in the asymmetric unit (Z' = 2) and has regions of local static disorder. This substance has been in phase IIa drug development trials for the treatment of chronic obstructive pulmonary disease, a disease which affects over 300 million people and contributes to nearly 3 million deaths annually...
June 28, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28613900/solid-state-nmr-provides-evidence-for-small-amplitude-slow-domain-motions-in-a-multispanning-transmembrane-%C3%AE-helical-protein
#12
Daryl Good, Charlie Pham, Jacob Jagas, Józef R Lewandowski, Vladimir Ladizhansky
Proteins are dynamic entities and populate ensembles of conformations. Transitions between states within a conformational ensemble occur over a broad spectrum of amplitude and time scales, and are often related to biological function. Whereas solid-state NMR (SSNMR) spectroscopy has recently been used to characterize conformational ensembles of proteins in the microcrystalline states, its applications to membrane proteins remain limited. Here we use SSNMR to study conformational dynamics of a seven-helical transmembrane (TM) protein, Anabaena Sensory Rhodopsin (ASR) reconstituted in lipids...
July 12, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28572641/application-of-nuclear-magnetic-resonance-spectroscopy-in-food-adulteration-determination-the-example-of-sudan-dye-i-in-paprika-powder
#13
Yaxi Hu, Shuo Wang, Shenlin Wang, Xiaonan Lu
Carcinogenic Sudan I has been added illegally into spices for an apparent freshness. (1)H solution and solid-state (SS) nuclear magnetic resonance (NMR) spectroscopies were applied and compared for determination of Sudan I in paprika powders (PPs). For solution NMR, PPs spiked with Sudan I were extracted with acetonitrile, centrifuged, rotor-evaporated, and re-dissolved in DMSO-d6 for spectral collection. For SSNMR, Sudan I contaminated PPs were mixed with DMSO-d6 solution and used for spectral collection. Linear regression models constructed for quantitative analyses resulted in the average accuracies for unknown samples as 98% and 105%, respectively...
June 1, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28560567/gd-3-chelated-lipid-accelerates-solid-state-nmr-spectroscopy-of-seven-transmembrane-proteins
#14
Chang Liu, Jing Liu, Xiaojun Xu, ShengQi Xiang, Shenlin Wang
Solid-state NMR (SSNMR) is an attractive technique for studying large membrane proteins in membrane-mimetic environments. However, SSNMR experiments often suffer from low efficiency, due to the inherent low sensitivity and the long recycle delays needed to recover the magnetization. Here we demonstrate that the incorporation of a small amount of a Gd(3+)-chelated lipid, Gd(3+)-DMPE-DTPA, into proteoliposomes greatly shortens the spin-lattice relaxation time ((1)H-T 1) of lipid-reconstituted membrane proteins and accelerates the data collection...
May 30, 2017: Journal of Biomolecular NMR
https://www.readbyqxmd.com/read/28548827/dynamic-disorder-and-electronic-structures-of-electron-precise-dianionic-diboranes-insights-from-solid-state-multinuclear-magnetic-resonance-spectroscopy
#15
Y T Angel Wong, Johannes Landmann, Maik Finze, David L Bryce
The J((11)B,(11)B) coupling constants of various salts of the electron-precise hexacyanodiborane(6) dianion, [B2(CN)6](2-), were obtained using (11)B double-quantum-filtered (DQF) J-resolved solid-state nuclear magnetic resonance (SSNMR) spectroscopy. Our results show that the magnitude of the DQF J splitting is influenced by both the crystallographic symmetry of the system and the presence of dynamics. The splittings are amplified by a factor of 3 as compared to the corresponding theoretical J coupling constants for cases where (1) there is an absence of dynamics but the boron pairs are crystallographically equivalent or (2) the boron pairs are crystallographically inequivalent but are rendered magnetically equivalent on the time scale of the experiment due to dynamic disorder, which was identified by (11)B and (13)C SSNMR experiments...
June 21, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28535056/solid-state-nmr-structure-based-inhibitor-design-to-achieve-selective-inhibition-of-the-parallel-in-register-%C3%AE-sheet-versus-antiparallel-iowa-mutant-%C3%AE-amyloid-fibrils
#16
Qinghui Cheng, Wei Qiang
Solid-state nuclear magnetic resonance (ssNMR) spectroscopy has been widely applied to characterize the high-resolution structures of β-amyloid (Aβ) fibrils. While these structures provide crucial molecular insights on the deposition of amyloid plaques in Alzheimer's diseases (AD), ssNMR structures have been rarely used so far as the basis for designing inhibitors. It remains a challenge because the ssNMR-based Aβ fibril structures were usually obtained with sparsely isotope-labeled peptides with limited experimental constraints, where the structural models, especially the side-chain coordinates, showed restricted precision...
May 30, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28511991/calculation-of-the-cross-sectional-shape-of-a-fibril-from-equatorial-scattering
#17
Biel Roig-Solvas, Lee Makowski
An alternate formulation of helical diffraction theory is used to generate cross-sectional shapes of fibrous structures from equatorial scattering. We demonstrate this approach with computationally generated scattering intensities and then apply it to scattering data from Tobacco Mosaic Virus (TMV) and in vitro assembled fibrils of Aβ40 peptides. Refining the cross-sectional shape of TMV from SAXS data collected on a 26mg/ml solution resulted in a circular shape with outer diameter of ∼180Å and inner diameter of ∼40Å consistent with the known structure of TMV...
May 13, 2017: Journal of Structural Biology
https://www.readbyqxmd.com/read/28501588/oligomeric-structure-of-anabaena-sensory-rhodopsin-in-a-lipid-bilayer-environment-by-combining-solid-state-nmr-and-long-range-deer-constraints
#18
Sergey Milikisiyants, Shenlin Wang, Rachel A Munro, Matthew Donohue, Meaghan E Ward, David Bolton, Leonid S Brown, Tatyana I Smirnova, Vladimir Ladizhansky, Alex I Smirnov
Oligomerization of membrane proteins is common in nature. Here, we combine spin-labeling double electron-electron resonance (DEER) and solid-state NMR (ssNMR) spectroscopy to refine the structure of an oligomeric integral membrane protein, Anabaena sensory rhodopsin (ASR), reconstituted in a lipid environment. An essential feature of such a combined approach is that it provides structural distance restraints spanning a range of ca 3-60Å while using the same sample preparation (i.e., mutations, paramagnetic labeling, and reconstitution in lipid bilayers) for both ssNMR and DEER...
June 16, 2017: Journal of Molecular Biology
https://www.readbyqxmd.com/read/28480926/confinement-effects-of-a-crystalline-sponge-on-ferrocene-and-ferrocene-carboxaldehyde
#19
Gabriel Brunet, Damir A Safin, Koen Robeyns, Glenn A Facey, Ilia Korobkov, Yaroslav Filinchuk, Muralee Murugesu
The pivotal role of ππ interactions in the inclusion behaviour of a series of organometallic sandwich compounds is studied through single-crystal X-ray diffraction. The confinement effects of a crystalline sponge host are investigated where, notably, we observe an enhanced rotation of the ligand ring once encapsulated by the nanoporous framework, as evidenced by SSNMR experiments.
May 8, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28471174/investigating-sodium-storage-mechanisms-in-tin-anodes-a-combined-pair-distribution-function-analysis-density-functional-theory-and-solid-state-nmr-approach
#20
Joshua M Stratford, Martin Mayo, Phoebe K Allan, Oliver Pecher, Olaf J Borkiewicz, Kamila M Wiaderek, Karena W Chapman, Chris J Pickard, Andrew J Morris, Clare P Grey
The alloying mechanism of high-capacity tin anodes for sodium-ion batteries is investigated using a combined theoretical and experimental approach. Ab initio random structure searching (AIRSS) and high-throughput screening using a species-swap method provide insights into a range of possible sodium-tin structures. These structures are linked to experiments using both average and local structure probes in the form of operando pair distribution function analysis, X-ray diffraction, and (23)Na solid-state nuclear magnetic resonance (ssNMR), along with ex situ (119)Sn ssNMR...
May 16, 2017: Journal of the American Chemical Society
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