keyword
MENU ▼
Read by QxMD icon Read
search

Deuterium

keyword
https://www.readbyqxmd.com/read/28102317/time-resolved-neutron-scattering-provides-new-insight-into-protein-substrate-processing-by-a-aaa-unfoldase
#1
Ziad Ibrahim, Anne Martel, Martine Moulin, Henry S Kim, Michael Härtlein, Bruno Franzetti, Frank Gabel
We present a combination of small-angle neutron scattering, deuterium labelling and contrast variation, temperature activation and fluorescence spectroscopy as a novel approach to obtain time-resolved, structural data individually from macromolecular complexes and their substrates during active biochemical reactions. The approach allowed us to monitor the mechanical unfolding of a green fluorescent protein model substrate by the archaeal AAA+ PAN unfoldase on the sub-minute time scale. Concomitant with the unfolding of its substrate, the PAN complex underwent an energy-dependent transition from a relaxed to a contracted conformation, followed by a slower expansion to its initial state at the end of the reaction...
January 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28096422/hydrogen-isotope-fractionation-in-methane-plasma
#2
François Robert, Sylvie Derenne, Guillaume Lombardi, Khaled Hassouni, Armelle Michau, Peter Reinhardt, Rémi Duhamel, Adriana Gonzalez, Kasia Biron
The hydrogen isotope ratio (D/H) is commonly used to reconstruct the chemical processes at the origin of water and organic compounds in the early solar system. On the one hand, the large enrichments in deuterium of the insoluble organic matter (IOM) isolated from the carbonaceous meteorites are interpreted as a heritage of the interstellar medium or resulting from ion-molecule reactions taking place in the diffuse part of the protosolar nebula. On the other hand, the molecular structure of this IOM suggests that organic radicals have played a central role in a gas-phase organosynthesis...
January 17, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28096372/helical-structure-stability-and-dynamics-in-human-apolipoprotein-e3-and-e4-by-hydrogen-exchange-and-mass-spectrometry
#3
Palaniappan S Chetty, Leland Mayne, Sissel Lund-Katz, S Walter Englander, Michael C Phillips
Apolipoprotein E (apoE) plays a critical role in cholesterol transport in both peripheral circulation and brain. Human apoE is a polymorphic 299-residue protein in which the less common E4 isoform differs from the major E3 isoform only by a C112R substitution. ApoE4 interacts with lipoprotein particles and with the amyloid-β peptide, and it is associated with increased incidence of cardiovascular and Alzheimer's disease. To understand the structural basis for the differences between apoE3 and E4 functionality, we used hydrogen-deuterium exchange coupled with a fragment separation method and mass spectrometric analysis to compare their secondary structures at near amino acid resolution...
January 17, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28095863/dietary-intake-of-n-3-pufas-modifies-the-absorption-distribution-and-bioavailability-of-fatty-acids-in-the-mouse-gastrointestinal-tract
#4
Qin Yang, Shunhe Wang, Yunqi Ji, Haiqin Chen, Hao Zhang, Wei Chen, Zhennan Gu, Yong Q Chen
BACKGROUND: Dietary polyunsaturated fatty acids (PUFAs), especially n-3 PUFAs, are important for human health. The intestinal tract, a location that is heavily colonized by microorganisms, is the main organ for absorbing fatty acids. METHODS: The purpose of this study was to analyze the effects of dietary n-3 and n-6 PUFAs on the distribution of different types of fatty acids and their bioavailability along the gut. Mice were fed for a week with experimental diets containing high n-3 or high n-6 fatty acid levels...
January 17, 2017: Lipids in Health and Disease
https://www.readbyqxmd.com/read/28095696/properties-of-lanthanide-hydroxide-molecules-produced-in-reactions-of-lanthanide-atoms-with-h2o2-and-h2-o2-mixtures-roles-of-the-i-ii-iii-and-iv-oxidation-states
#5
Xuefeng Wang, Lester Andrews, Zongtang Fang, Kanchana Sahan Thanthiriwatte, Mingyang Chen, David A Dixon
The reactions of laser-ablated lanthanide metal atoms with hydrogen peroxide or hydrogen plus oxygen mixtures have been studied experimentally in a solid argon matrix and theoretically with the ab initio MP2 and CCSD(T) methods. The Ln(OH)3 and Ln(OH)2 molecules and Ln(OH)2(+) cations are the major products and the reactions to form those hydroxides are predicted to be highly exothermic at the CCSD(T) level. Vibronic interations are hypothesized to contribute to the abnormalities in deuterium shifts for Ln-OH(D) stretching modes for several hydroxides, consistent with CASSCF calculations...
January 17, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28092705/o-h-activation-by-an-unexpected-ferryl-intermediate-during-catalysis-by-2-hydroxyethylphosphonate-dioxygenase
#6
Spencer C Peck, Chen Wang, Laura M K Dassama, Bo Zhang, Yisong Guo, Lauren J Rajakovich, J Martin Bollinger, Carsten Krebs, Wilfred A van der Donk
Activation of O-H bonds by inorganic metal-oxo complexes has been documented, but no cognate enzymatic process is known. Our mechanistic analysis of 2-hydroxyethylphosphonate dioxygenase (HEPD), which cleaves the C1-C2 bond of its substrate to afford hydroxymethylphosphonate on the biosynthetic pathway to the commercial herbicide phosphinothricin, uncovered an example of such an O-H-bond-cleavage event. Stopped-flow UV-visible absorption and freeze-quench Mössbauer experiments identified a transient iron(IV)-oxo (ferryl) complex...
January 16, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28089477/bioimpedance-and-fluid-status-in-children-and-adolescents-treated-with-dialysis
#7
Gregorio P Milani, Jaap W Groothoff, Federica A Vianello, Emilio F Fossali, Fabio Paglialonga, Alberto Edefonti, Carlo Agostoni, Dario Consonni, Dewi van Harskamp, Johannes B van Goudoever, Henk Schierbeek, Michiel J S Oosterveld
BACKGROUND: Assessment of hydration status in patients with chronic kidney failure treated by dialysis is crucial for clinical management decisions. Dilution techniques are considered the gold standard for measurement of body fluid volumes, but they are unfit for day-to-day care. Multifrequency bioimpedance has been shown to be of help in clinical practice in adults and its use in children and adolescents has been advocated. We investigated whether application of multifrequency bioimpedance is appropriate for total-body water (TBW) and extracellular water (ECW) measurement in children and adolescents on dialysis therapy...
January 12, 2017: American Journal of Kidney Diseases: the Official Journal of the National Kidney Foundation
https://www.readbyqxmd.com/read/28088851/monitoring-the-reaction-process-during-the-s2%C3%A2-s3-transition-in-photosynthetic-water-oxidation-using-time-resolve-infrared-spectroscopy
#8
Hiroki Sakamoto, Tatsuki Shimizu, Ryo Nagao, Takumi Noguchi
Photosynthetic water oxidation performed at the Mn4CaO5 cluster in photosystem II plays a crucial role in energy production as electron and proton sources necessary for CO2 fixation. Molecular oxygen, a byproduct, is a source of the oxygenic atmosphere that sustains life on earth. However, the molecular mechanism of water oxidation is not yet well understood. In the reaction cycle of intermediates called S states, the S2→S3 transition is particularly important; it consists of multiple processes of electron transfer, proton release, and water insertion, and generates an intermediate leading to O-O bond formation...
January 16, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28078979/biotechnological-patents-applications-of-the-deuterium-oxide-in-human-health
#9
Alexsandro S Galdino, Reysla M da S Mariano, Wendell C Bila, Maria Jaciara F Trindade, Joel Alves Lamounier
BACKGROUND: Deuterium oxide is a molecule that has been used for decades in several studies related to human health. Currently, studies on D2O have mobilized a "Race for Patenting" worldwide. Several patents have been registered from biomedical and technological studies of D2O showing the potential of this stable isotope in industry and health care ecosystems. METHODS: Most of the patents relating to applications of the deuterium oxide in human health have been summarized in this review...
January 12, 2017: Recent Patents on Biotechnology
https://www.readbyqxmd.com/read/28078892/dynamical-transitions-at-low-temperatures-in-the-nearest-hydration-shell-of-phospholipid-bilayers
#10
Victoria N Syryamina, Sergei Andreevich Dzuba
For the so-called dynamical transition from harmonic to anharmonic (or diffusive) motions in biological systems, the presence of hydration water is important. To explain the molecular mechanism of this transition, the information on molecular motions in the nearest hydration shell would be helpful. In this work, to study molecular motions in the nearest hydration shell of spin-labeled model biological membranes, a pulsed version of electron paramagnetic resonance (EPR)-electron spin echo envelope modulation (ESEEM) spectroscopy-is employed...
January 12, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28077807/folding-of-apomyoglobin-analysis-of-transient-intermediate-structure-during-refolding-using-quick-hydrogen-deuterium-exchange-and-nmr
#11
Chiaki Nishimura
The structures of apomyoglobin folding intermediates have been widely analyzed using physical chemistry methods including fluorescence, circular dichroism, small angle X-ray scattering, NMR, mass spectrometry, and rapid mixing. So far, at least two intermediates (on sub-millisecond- and millisecond-scales) have been demonstrated for apomyoglobin folding. The combination of pH-pulse labeling and NMR is a useful tool for analyzing the kinetic intermediates at the atomic level. Its use has revealed that the latter-phase kinetic intermediate of apomyoglobin (6 ms) was composed of helices A, B, G and H, whereas the equilibrium intermediate, called the pH 4 molten-globule intermediate, was composed mainly of helices A, G and H...
2017: Proceedings of the Japan Academy. Series B, Physical and Biological Sciences
https://www.readbyqxmd.com/read/28077375/body-composition-diet-and-physical-activity-a-longitudinal-cohort-study-in-preschoolers-with-cerebral-palsy
#12
Stina Oftedal, Peter Sw Davies, Roslyn N Boyd, Richard D Stevenson, Robert S Ware, Piyapa Keawutan, Katherine A Benfer, Kristie L Bell
BACKGROUND: Altered body composition in children with cerebral palsy (CP) could be due to differences in energy intake, habitual physical activity (HPA), and sedentary time. OBJECTIVE: We investigated the longitudinal relation between the weight-for-age z score (WZ), fat-free mass (FFM), percentage of body fat (%BF), and modifiable lifestyle factors for all Gross Motor Function Classification System (GMFCS) levels (I-V). DESIGN: The study was a longitudinal population-based cohort study of children with CP who were aged 18-60 mo (364 assessments in 161 children; boys: 61%; mean ± SD recruitment age: 2...
January 11, 2017: American Journal of Clinical Nutrition
https://www.readbyqxmd.com/read/28075562/evidence-for-a-di-%C3%A2%C2%B5-oxo-diamond-core-in-the-mn-iv-fe-iv-activation-intermediate-of-ribonucleotide-reductase-from-chlamydia-trachomatis
#13
Ryan J Martinie, Elizabeth J Blaesi, Carsten Krebs, J Martin Bollinger, Alexey Silakov, Christopher J Pollock
High-valent iron and manganese complexes effect some of the most challenging biochemical reactions known, including hydrocarbon and water oxidations associated with the global carbon cycle and oxygenic photosynthesis, respectively. Their extreme reactivity presents an impediment to structural characterization, but their biological importance and potential chemical utility have, nevertheless, motivated extensive efforts toward that end. Several such intermediates accumulate during activation of class I ribonucleotide reductase (RNR) β subunits, which self-assemble dimetal cofactors with stable one-electron oxidants that serve to initiate the enzyme's free-radical mechanism...
January 11, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28074361/partially-deuterated-samples-of-het-s-218-289-fibrils-assignment-and-deuterium-isotope-effect
#14
Albert A Smith, Francesco Ravotti, Emilie Testori, Riccardo Cadalbert, Matthias Ernst, Anja Böckmann, Beat H Meier
Fast magic-angle spinning and partial sample deuteration allows direct detection of (1)H in solid-state NMR, yielding significant gains in mass sensitivity. In order to further analyze the spectra, (1)H detection requires assignment of the (1)H resonances. In this work, resonance assignments of backbone H(N) and Hα are presented for HET-s(218-289) fibrils, based on the existing assignment of Cα, Cβ, C', and N resonances. The samples used are partially deuterated for higher spectral resolution, and the shifts in resonance frequencies of Cα and Cβ due to the deuterium isotope effect are investigated...
January 10, 2017: Journal of Biomolecular NMR
https://www.readbyqxmd.com/read/28074063/direct-in-vivo-evidence-for-increased-proliferation-of-cll-cells-in-lymph-nodes-compared-to-bone-marrow-and-peripheral-blood
#15
T M Herndon, S-S Chen, N S Saba, J Valdez, C Emson, M Gatmaitan, X Tian, T E Hughes, C Sun, D C Arthur, M Stetler-Stevenson, C M Yuan, C U Niemann, G E Marti, G Aue, S Soto, M Z H Farooqui, S E M Herman, N Chiorazzi, A Wiestner
Chronic Lymphocytic Leukemia (CLL) is a progressive malignancy of mature B-cells that involves the peripheral blood (PB), lymph nodes (LNs) and bone marrow (BM). While the majority of CLL cells are in a resting state, small populations of proliferating cells exist; however, the anatomical site of active cell proliferation remains to be definitively determined. Based on findings that CLL cells in LNs have increased expression of B-cell activation genes, we tested the hypothesis that the fraction of 'newly born' cells would be highest in the LNs...
January 11, 2017: Leukemia: Official Journal of the Leukemia Society of America, Leukemia Research Fund, U.K
https://www.readbyqxmd.com/read/28069412/influence-of-glutamic-acid-residues-and-ph-on-the-properties-of-transmembrane-helices
#16
Venkatesan Rajagopalan, Denise V Greathouse, Roger E Koeppe
Negatively charged side chains are important for the function of particular ion channels and certain other membrane proteins. To investigate the influence of single glutamic acid side chains on helices that span lipid-bilayer membranes, we have employed GWALP23 (acetyl-GGALW(5)LALALALALALALW(19)LAGA-amide) as a favorable host peptide framework. We substituted individual Leu residues with Glu residues (L12E or L14E or L16E) and incorporated specific (2)H-labeled alanine residues within the core helical region or near the ends of the sequence...
January 7, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28069117/promotion-effect-of-sulfite-on-deoxyosones-and-4-methylimidazole-in-caramel-model-system
#17
Xian-Bing Xu, Pei Yu, Shu-Juan Yu
In this study, hydrogen-deuterium (H/D) exchange experiment was carried out to reveal the promotion effect of sulfite on the formation of deoxyosones and 4-methylimidazole (4-MeI) in the Maillard reaction. Glucose-ammonium (40mmol/L, pH 7.4 in PBS) model systems with different levels of sulfite were incubated at 110°C for 2h. Alpha-dicarbonyls were detected after derivatization by a high-performance liquid chromatography with a diode array detector (HPLC-DAD). 4-MeI in the Maillard reaction was tested using a high-performance anion exchange chromatography with an electrochemical detector (HPAEC-ED)...
May 15, 2017: Food Chemistry
https://www.readbyqxmd.com/read/28068102/enantioselective-palladium-catalyzed-oxidative-cascade-cyclization-of-aliphatic-alkenyl-amides
#18
Wei Du, Qiangshuai Gu, Yang Li, Zhenyang Lin, Dan Yang
The catalyst system of Pd(TFA)2/(S,S)-diPh-pyrox is reported to promote the highly efficient enantioselective oxidative cascade cyclization of alkene-tethered aliphatic acrylamides under mild aerobic conditions. A series of pyrrolizidine derivatives have been synthesized in good yield and excellent enantioselectivity. Deuterium-labeling experiments have revealed that the reaction proceeded through an anti-aminopalladation (anti-AP) pathway with high selectivity. The transition states for the anti-AP step have been calculated to account for the observed enantioselectivity...
January 9, 2017: Organic Letters
https://www.readbyqxmd.com/read/28068058/extensive-turnover-of-compatible-solutes-in-cyanobacteria-revealed-by-deuterium-oxide-d2o-stable-isotope-probing
#19
Richard Baran, Rebecca Lau, Benjamin P Bowen, Spencer Diamond, Nick Jose, Ferran Garcia-Pichel, Trent R Northen
Cyanobacteria are important primary producers of organic matter in diverse environments on a global scale. While mechanisms of CO2 fixation are well understood, the distribution of the flow of fixed organic carbon within individual cells and complex microbial communities is less well characterized. To obtain a general overview of metabolism, we describe the use of deuterium oxide (D2O) to measure deuterium incorporation into the intracellular metabolites of two physiologically diverse cyanobacteria: a terrestrial filamentous strain (Microcoleus vaginatus PCC 9802) and a euryhaline unicellular strain (Synechococcus sp...
January 18, 2017: ACS Chemical Biology
https://www.readbyqxmd.com/read/28063489/using-hydrogen-deuterium-exchange-mass-spectrometry-to-examine-protein-membrane-interactions
#20
O Vadas, M L Jenkins, G L Dornan, J E Burke
Many fundamental cellular processes are controlled via assembly of a network of proteins at membrane surfaces. The proper recruitment of proteins to membranes can be controlled by a wide variety of mechanisms, including protein lipidation, protein-protein interactions, posttranslational modifications, and binding to specific lipid species present in membranes. There are, however, only a limited number of analytical techniques that can study the assembly of protein-membrane complexes at the molecular level. A relatively new addition to the set of techniques available to study these protein-membrane systems is the use of hydrogen-deuterium exchange mass spectrometry (HDX-MS)...
2017: Methods in Enzymology
keyword
keyword
46127
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"