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5-ala nmr

Qing Zhe Ni, Evgeny Markhasin, Thach V Can, Björn Corzilius, Kong Ooi Tan, Alexander B Barnes, Eugenio Daviso, Yongchao Su, Judith Herzfeld, Robert G Griffin
In DNP MAS NMR experiments at ∼80-110 K, the structurally important -(13)CH3 and -(15)NH3(+) signals in MAS spectra of biological samples disappear due to the interference of the molecular motions with the (1)H decoupling. Here we investigate the effect of these dynamic processes on the NMR line shapes and signal intensities in several typical systems: (1) microcrystalline APG, (2) membrane protein bR, (3) amyloid fibrils PI3-SH3, (4) monomeric alanine-CD3, and (5) the protonated and deuterated dipeptide N-Ac-VL over 78-300 K...
May 10, 2017: Journal of Physical Chemistry. B
Tetsuo Asakura, Masanori Endo, Misaki Hirayama, Hiroki Arai, Akihiro Aoki, Yugo Tasei
In order to improve the stiff and brittle characteristics of pure Bombyx mori (B. mori) silk fibroin (SF) film in the dry state, glycerin (Glyc) has been used as a plasticizer. However, there have been very limited studies on the structural characterization of the Glyc-blended SF film. In this study, (13)C Cross Polarization/Magic Angle Spinning nuclear magnetic resonance (CP/MAS NMR) was used to monitor the conformational changes in the films by changing the Glyc concentration. The presence of only 5 wt % Glyc in the film induced a significant conformational change in SF where Silk I* (repeated type II β-turn and no α-helix) newly appeared...
September 9, 2016: International Journal of Molecular Sciences
Susanne Vogt, Simone Wahl, Johannes Kettunen, Susanne Breitner, Gabi Kastenmüller, Christian Gieger, Karsten Suhre, Melanie Waldenberger, Jürgen Kratzsch, Markus Perola, Veikko Salomaa, Stefan Blankenberg, Tanja Zeller, Pasi Soininen, Antti J Kangas, Annette Peters, Harald Grallert, Mika Ala-Korpela, Barbara Thorand
BACKGROUND: Numerous observational studies have observed associations between vitamin D deficiency and cardiometabolic diseases, but these findings might be confounded by obesity. A characterization of the metabolic profile associated with serum 25-hydroxyvitamin D [25(OH)D] levels, in general and stratified by abdominal obesity, may help to untangle the relationship between vitamin D, obesity and cardiometabolic health. METHODS: Serum metabolomics measurements were obtained from a nuclear magnetic resonance spectroscopy (NMR)- and a mass spectrometry (MS)-based platform...
September 7, 2016: International Journal of Epidemiology
Ashley N Martfeld, Denise V Greathouse, Roger E Koeppe
We address the critically important ionization properties of histidine side chains of membrane proteins, when exposed directly to lipid acyl chains within lipid bilayer membranes. The problem is important for addressing general principles that may underlie membrane protein function. To this end, we have employed a favorable host peptide framework provided by GWALP23 (acetyl-GGALW(5)LALALALALALALW(19)LAGA-amide). We inserted His residues into position 12 or 14 of GWALP23 (replacing either Leu(12) or Leu(14)) and incorporated specific [(2)H]Ala labels within the helical core sequence...
September 2, 2016: Journal of Biological Chemistry
Joanna Makowska, Krzysztof Żamojć, Dariusz Wyrzykowski, Wioletta Żmudzińska, Dorota Uber, Małgorzata Wierzbicka, Wiesław Wiczk, Lech Chmurzyński
Steady-state and time-resolved fluorescence quenching measurements supported by isothermal titration calorimetry (ITC) and molecular dynamics simulations (MD), with the NMR-derived restraints, were used to investigate the interactions of Cu(2+) ions with a fragment of the Aβ(1-42) polypeptide, Aβ(5-16) with the following sequence: Ac-Arg-His-Asp-Ser-Gly-Tyr-Glu-Val-His-His-Gln-Lys-NH2, denoted as HZ1. The studies presented in this paper, when compared with our previous results (Makowska et al., Spectrochim...
September 2016: Biophysical Chemistry
Alaa-Eldin F Nassar, Adam V Wisnewski, Ivan King
This review highlights the recent research into the biotransformations and rearrangement of the sulfonylhydrazine-alkylating agent laromustine. Incubation of [(14)C]laromustine with rat, dog, monkey, and human liver microsomes produced eight radioactive components (C-1 to C-8). There was little difference in the metabolite profile among the species examined, partly because NADPH was not required for the formation of most components, which instead involved decomposition and/or hydrolysis. The exception was C-7, a hydroxylated metabolite, largely formed by CYP2B6 and CYP3A4/5...
August 2016: Drug Metabolism and Disposition: the Biological Fate of Chemicals
James Chang, Hongyu Zhou, Maria Preobrazhenskaya, Peng Tao, Sung Joon Kim
Glycopeptide antibiotics inhibit cell wall biosynthesis in Gram-positive bacteria by targeting the peptidoglycan (PG) pentapeptide stem structure (l-Ala-d-iso-Gln-l-Lys-d-Ala-d-Ala). Structures of the glycopeptide complexed with a PG stem mimic have shown that the d-Ala-d-Ala segment is the primary drug binding site; however, biochemical evidence suggests that the glycopeptide-PG interaction involves more than d-Ala-d-Ala binding. Interactions of the glycopeptide with the non-d-Ala-d-Ala segment of the PG stem were investigated using solid-state nuclear magnetic resonance (NMR)...
June 21, 2016: Biochemistry
Huy N Hoang, Russell W Driver, Renée L Beyer, Timothy A Hill, Aline D de Araujo, Fabien Plisson, Rosemary S Harrison, Lena Goedecke, Nicholas E Shepherd, David P Fairlie
Cyclic pentapeptides (e.g. Ac-(cyclo-1,5)-[KAXAD]-NH2 ; X=Ala, 1; Arg, 2) in water adopt one α-helical turn defined by three hydrogen bonds. NMR structure analysis reveals a slight distortion from α-helicity at the C-terminal aspartate caused by torsional restraints imposed by the K(i)-D(i+4) lactam bridge. To investigate this effect on helix nucleation, the more water-soluble 2 was appended to N-, C-, or both termini of a palindromic peptide ARAARAARA (≤5 % helicity), resulting in 67, 92, or 100 % relative α-helicity, as calculated from CD spectra...
July 11, 2016: Angewandte Chemie
Pedro Lameiras, Jean-Marc Nuzillard
The use of two new highly viscous binary solvents, DMSO-d6/glycerol (GL) and DMSO-d6/glycerol-d8 (GL-d8), is reported for the first time in order to give access to the individual NMR spectra of mixture components. Their high dissolution power offers a wide range of potential applications to mixture analysis, regardless of polarity. Under particular conditions of viscosity, the tumbling rate of small and medium-sized molecules slows down in solution, so that the longitudinal cross-relaxation regime favors the observation of spin diffusion...
April 19, 2016: Analytical Chemistry
Peter Würtz, Qin Wang, Pasi Soininen, Antti J Kangas, Ghazaleh Fatemifar, Tuulia Tynkkynen, Mika Tiainen, Markus Perola, Therese Tillin, Alun D Hughes, Pekka Mäntyselkä, Mika Kähönen, Terho Lehtimäki, Naveed Sattar, Aroon D Hingorani, Juan-Pablo Casas, Veikko Salomaa, Mika Kivimäki, Marjo-Riitta Järvelin, George Davey Smith, Mauno Vanhala, Debbie A Lawlor, Olli T Raitakari, Nish Chaturvedi, Johannes Kettunen, Mika Ala-Korpela
BACKGROUND: Statins are first-line therapy for cardiovascular disease prevention, but their systemic effects across lipoprotein subclasses, fatty acids, and circulating metabolites remain incompletely characterized. OBJECTIVES: This study sought to determine the molecular effects of statin therapy on multiple metabolic pathways. METHODS: Metabolic profiles based on serum nuclear magnetic resonance metabolomics were quantified at 2 time points in 4 population-based cohorts from the United Kingdom and Finland (N = 5,590; 2...
March 15, 2016: Journal of the American College of Cardiology
D Preiss, N Rankin, P Welsh, R R Holman, A J Kangas, P Soininen, P Würtz, M Ala-Korpela, N Sattar
AIMS: To investigate whether metformin therapy alters circulating aromatic and branched-chain amino acid concentrations, increased levels amino acid concentrations, increased levels of which have been found to predict Type 2 diabetes. METHODS: In the Carotid Atherosclerosis: Metformin for Insulin Resistance (CAMERA) study (NCT00723307), 173 individuals without Type 2 diabetes, but with coronary disease, were randomized to metformin (n=86) or placebo (n=87) for 18 months...
November 2016: Diabetic Medicine: a Journal of the British Diabetic Association
Bing-Xin Liu, Qiong Guo, Guang-Tian Peng, Xi-Xin He, Xiao-Jie Chen, Ling-Fang Lei, Yun Deng, Xian Jun Su, Cui-Xian Zhang
One new cyclic tetrapeptide cyclic-(Tyr-Ala-Leu-Ser) (1) along with four natural compounds firstly obtained 3H-imidazole-4-carboxylic acid (2), 2-methyl-3H-imidazole-4-carboxylic acid (3), 3-ethylidene-6-isopropyl-piperazine-2,5-dione (4), and 3-isobutylidene-6-methyl piperazine-2,5-dione (5) have been isolated from the coral derived endophytic bacteria Brevibacterium sp. L-4 collected from the South China Sea. Their structures were elucidated through spectroscopic techniques including NMR (1D and 2D), MS, and EA, and their relative configurations were also assigned by NMR analysis...
2016: Natural Product Research
Mark Lefever, Yingxue Li, Bobbi Anglin, Dhanasekaran Muthu, Denise Giuvelis, John J Lowery, Brian I Knapp, Jean M Bidlack, Edward J Bilsky, Robin Polt
Glycopeptides related to β-endorphin penetrate the blood-brain barrier (BBB) of mice to produce antinociception. Two series of glycopeptides were assessed for opioid receptor binding affinity. Attempts to alter the mu-selectivity of [D-Ala(2),N-MePhe(4),Gly-ol(5)]enkephalin (DAMGO)-related glycopeptides by altering the charged residues of the amphipathic helical address were unsuccessful. A series of pan-agonists was evaluated for antinociceptive activity (55 °C tail flick) in mice. A flexible linker was required to maintain antinociceptive activity...
August 13, 2015: Journal of Medicinal Chemistry
Rashmi Mukherjee, Chaitali Datta Ray, Sabyasachi Ray, Swagata Dasgupta, Koel Chaudhury
OBJECTIVE: Metabolic anomalies, if any, between early and late onset preeclampsia [PE] were explored using Fourier transform infrared [FTIR] spectroscopy. SETTING: Department of Gynecology and Obstetrics, SSKM Hospital, IPGMER, Kolkata and Midnapur Medical College Hospital, Midnapur, India. SAMPLE: 80 pregnant women attending routine antenatal care units; (i) early onset PE [gestational age; GA<34weeks] (ii) late onset PE [GA>34weeks] (iii) early onset control [GA 24-34weeks] and (iv) late onset control [GA>34weeks]...
January 2014: Pregnancy Hypertension
Zhen-Yu Li, Ma-Li Fan, Xue-Mei Qin
To compare the chemical change of Paeoniae Radix Alba (PRA) after vinegar-baking processing, as well as the effect of vinegar types exerted on the processing, 1H NMR-based metabolomic approach combined with multivariate statistical analysis was used to investigate the different metabolites between the raw and two vinegar-baked PRA. More than thirty metabolites were identified in the 1H NMR spectrum of PRA, and the multivariate statistical analysis showed that raw and two vinegar-baked PRA could be separated obviously...
February 2015: Yao Xue Xue Bao, Acta Pharmaceutica Sinica
Clotilde Marín, Inmaculada Ramírez-Macías, María José Rosales, Beatriz Muro, Felipe Reviriego, Pilar Navarro, Vicente J Arán, Manuel Sánchez-Moreno
The antiprotozoal activity of some indazole-derived amines (2, 3, 5-8) as well as that of some simple structurally related 3-alkoxy-1-alkyl-5-nitroindazoles (1, 4) against promastigote and amastigote forms of Leishmania infantum and Leishmania braziliensis is reported. In some cases, these compounds showed in vitro activities against the different morphological forms of Leishmania similar to or higher than those of the reference drug glucantime; this fact, along with low unspecific cytotoxicities against macrophages shown by some of them, led to good selectivity indexes (SI)...
August 2015: Acta Tropica
Sara Pellegrino, Andrea Bonetti, Francesca Clerici, Alessandro Contini, Alessandro Moretto, Raffaella Soave, Maria Luisa Gelmi
A new α,α-disubstituted constrained glutamine analogue has been designed to decorate gold nanoparticles and to induce a 310-helix when inserted in peptides. Using an efficient "one-pot" asymmetric Schmidt reaction between 4-disubstituted-cyclohexanone and hydroxyalkylazides, 1H-azepine-2-oxo-5-amino-5-carboxylic acid was prepared. The main (R) isomer was inserted at the N-terminus in a very short peptide sequence (i.e., PhCO-(R)-Oxo-Azn-L-Ala-Aib-L-AlaNHMe) and a stable 310-helix conformation was obtained, as verified by both NMR experiments and molecular dynamics (MD) simulations...
June 5, 2015: Journal of Organic Chemistry
Adrian Drazic, Erika Kutzner, Jeannette Winter, Wolfgang Eisenreich
Hypochlorite is a reactive oxygen species that is worldwide as an antibacterial disinfectant. Hypochlorite exposure is known to cause oxidative damage to DNA and proteins. As a response to these effects, the metabolite profiles of organisms treated with sub-lethal doses of hypochlorite are assumed to be severely modified; however, the nature of these changes is hardly understood. Therefore, using nuclear magnetic resonance spectroscopy and gas chromatography-coupled mass spectrometry, we analyzed the time-dependent impact of hypochlorite exposure with a sub-lethal concentration (50 µM) on the metabolite profile of the Escherichia coli strain MG1655...
2015: PloS One
Masako Fujiwara, Itiro Ando, Kazuhisa Takeuchi, Shiro Oguma, Hiroshi Sato, Hiroshi Sekino, Keisuke Sato, Yutaka Imai
A large proportion of patients with end-stage renal disease have lifelong hemodialysis (HD) treatment. HD rapidly and indiscriminately removes necessary small metabolites together with uremic toxins from plasma into dialysate. To investigate metabolic responses to HD, we determined the levels of metabolites through time-course monitoring of (1)H NMR spectroscopy of dialysate during HD. The dialysate sample is stable for analysis because it contains only small metabolites without proteins. It was collected non-invasively from 9 HD patients with chronic glomerular nephropathy, at 6 time points during 4h of HD in 5 sessions...
2015: Journal of Pharmaceutical and Biomedical Analysis
Xuan Shi, Huihui Ma, Changqing Tong, Min Qu, Qiao Jin, Wei Li
A water-soluble polysaccharide was isolated from Crassostrea gigas (CGPS-1) by hot-water extraction, isoelectric precipitation, hydrolysis and ultrafiltration without using ethanol. Based on the calibration with Dextran, CGPS-1 had a molecular weight of approximately 6.5×10(6) Da. CGPS-1 was analyzed using high-performance liquid chromatography, Fourier-transform infrared spectroscopy and (1)H and (13)C nuclear magnetic resonance spectroscopy. Based on the data, CGPS-1 was found to be a uniform glucose polymer...
2015: International Journal of Biological Macromolecules
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