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1.
Carolyn E. Mountford George Grossman Alan W. Hampson Kerry T. Holmes 《Biochimica et Biophysica Acta (BBA)/Molecular Cell Research》1982,720(1):65-74
High resolution 1H-NMR spectroscopy has been used to study the infection of chicken embryo fibroblasts by influenza virus. Marked changes in the NMR spectrum occur when infectious influenza virus is introduced into the fibroblasts and these changes appear to depend upon the presence of active neuraminidase (EC 3.2.1.18). A crude preparation of neuraminidase from Vibrio cholerae is able to effect similar changes. Only minor spectral changes are observed in the absence of culture medium or when the viral genome material is inactivated by β-propiolactone. Similarly, little change is seen in the NMR spectrum when amantadine, which is thought to inhibit uncoating of the virus inside the cell, or actinomycin D, which inhibits cellular nucleic acid metabolism, are incubated with fibroblasts prior to the addition of virus. The results suggest that neuraminidase, in co-operation with a factor in the infectious process, initiates a cellular event which can be monitored by NMR. The nature of this cellular mechanism is unknown, but further studies are under way to determine its importance in viral infection. 相似文献
2.
Bettina Ughy Vclav Karlický Ondej Dlouhý Uro Javornik Zuzana Materov Ott Zsiros Primo ket Janez Plavec Vladimír punda Gyz Garab 《Physiologia plantarum》2019,166(1):278-287
Earlier experiments, using 31P‐NMR and time‐resolved merocyanine fluorescence spectroscopy, have shown that isolated intact, fully functional plant thylakoid membranes, in addition to the bilayer phase, contain three non‐bilayer (or non‐lamellar) lipid phases. It has also been shown that the lipid polymorphism of thylakoid membranes can be characterized by remarkable plasticity, i.e. by significant variations in 31P‐NMR signatures. However, changes in the lipid‐phase behaviour of thylakoids could not be assigned to changes in the overall membrane organization and the photosynthetic activity, as tested by circular dichroism and 77 K fluorescence emission spectroscopy and the magnitude of the variable fluorescence of photosystem II, which all showed only marginal variations. In this work, we investigated in more detail the temporal stability of the different lipid phases by recording 31P‐NMR spectra on isolated thylakoid membranes that were suspended in sorbitol‐ or NaCl‐based media. We observed, at 5°C during 8 h in the dark, substantial gradual enhancement of the isotropic lipid phases and diminishment of the bilayer phase in the sorbitol‐based medium. These changes compared well with the gradually increasing membrane permeability, as testified by the gradual acceleration of the decay of flash‐induced electrochromic absorption changes and characteristic changes in the kinetics of fast chlorophyll a‐fluorescence transients; all variations were much less pronounced in the NaCl‐based medium. These observations suggest that non‐bilayer lipids and non‐lamellar lipid phases play significant roles in the structural dynamics and functional plasticity of thylakoid membranes. 相似文献
3.
Amelia R. Hofstetter Juan A. De La Cruz Weiping Cao Jenish Patel Jessica A. Belser James McCoy Justine S. Liepkalns Samuel Amoah Guangjie Cheng Priya Ranjan Becky A. Diebold Wun-Ju Shieh Sherif Zaki Jacqueline M. Katz Suryaprakash Sambhara J. David Lambeth Shivaprakash Gangappa 《PloS one》2016,11(2)
The role of the reactive oxygen species-producing NADPH oxidase family of enzymes in the pathology of influenza A virus infection remains enigmatic. Previous reports implicated NADPH oxidase 2 in influenza A virus-induced inflammation. In contrast, NADPH oxidase 1 (Nox1) was reported to decrease inflammation in mice within 7 days post-influenza A virus infection. However, the effect of NADPH oxidase 1 on lethality and adaptive immunity after influenza A virus challenge has not been explored. Here we report improved survival and decreased morbidity in mice with catalytically inactive NADPH oxidase 1 (Nox1*/Y) compared with controls after challenge with A/PR/8/34 influenza A virus. While changes in lung inflammation were not obvious between Nox1*/Y and control mice, we observed alterations in the T cell response to influenza A virus by day 15 post-infection, including increased interleukin-7 receptor-expressing virus-specific CD8+ T cells in lungs and draining lymph nodes of Nox1*/Y, and increased cytokine-producing T cells in lungs and spleen. Furthermore, a greater percentage of conventional and interstitial dendritic cells from Nox1*/Y draining lymph nodes expressed the co-stimulatory ligand CD40 within 6 days post-infection. Results indicate that NADPH oxidase 1 modulates the innate and adaptive cellular immune response to influenza virus infection, while also playing a role in host survival. Results suggest that NADPH oxidase 1 inhibitors may be beneficial as adjunct therapeutics during acute influenza infection. 相似文献
4.
A series of novel, highly sensitive, and selective azo‐based anion sensors 1–3 have been designed and synthesized from the condensation reaction between 4‐amino azo benzene and three different aldehydes. The structure of the sensors 1–3 were confirmed by IR, HRMS, 1H NMR, and 13C NMR spectroscopic methods. Colorimetric naked‐eye analysis revealed the anion detection by receptors 2 and 3 as color changes from yellow to pink and yellow to orange, respectively. Anion sensing ability of all receptors was further investigated by 1H NMR titration, UV‐vis experiment, and fluorescence titration. UV‐vis measurements highly indicate the selective recognition of fluoride and acetate ions in 9:1 dimethyl sulfoxide–H2O (v/v) for receptors 2 and 3. Binding constant value showed among all receptors, receptor 3 has strong affinity toward F? and AcO? in semi‐aqueous medium, which is due to the presence of chromogenic signaling unit in it. The F? ion detection property of receptor 2 in organic medium was also extended in the real sample like toothpaste. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
5.
Miroslava Cuperlovic-Culf Lipu Wang Lily Forseille Kerry Boyle Nadine Merkley Ian Burton Pierre R. Fobert 《PloS one》2016,11(4)
Metabolic changes in spikelets of wheat varieties FL62R1, Stettler, Muchmore and Sumai3 following Fusarium graminearum infection were explored using NMR analysis. Extensive 1D and 2D 1H NMR measurements provided information for detailed metabolite assignment and quantification leading to possible metabolic markers discriminating resistance level in wheat subtypes. In addition, metabolic changes that are observed in all studied varieties as well as wheat variety specific changes have been determined and discussed. A new method for metabolite quantification from NMR data that automatically aligns spectra of standards and samples prior to quantification using multivariate linear regression optimization of spectra of assigned metabolites to samples’ 1D spectra is described and utilized. Fusarium infection-induced metabolic changes in different wheat varieties are discussed in the context of metabolic network and resistance. 相似文献
6.
7.
Ricardo Gonzalez-Mendez David Wemmer George Hahn Norma Wade-Jardetzky Oleg Jardetzky 《Biochimica et Biophysica Acta (BBA)/Molecular Cell Research》1982,720(3):274-280
A continuous-flow NMR culture system for mammalian cells has been developed on which 31P-NMR experiments under complete and strictly physiologic conditions have been performed. Observations on the response of the cellular metabolism to stresses such as starvation, low temperature and changes in environmental pH monitored by 31P-NMR are reported. The response of the intracellular pH relative to the external pH of the growth medium is studied. We find that under the experimental conditions used there exists a ΔpH varying between less than 0.2 and more than 0.6 pH units. These results are compatible with those obtained using other techniques. 相似文献
8.
The single channel conductivity of the gramicidin channel has been measured for all the alkali ions using both H2O and 2H2O as a medium. Significant changes in conductivity with medium have been observed in all cases except lithium. 相似文献
9.
Suk Weon Kim Bon Cho Koo Jonghyun Kim Jang Ryol Liu 《Biotechnology and Bioprocess Engineering》2007,12(6):653-661
Whole cell extracts ofArabidopsis cell cultures maintained on various sucrose concentrations (0,3, and 6%) were analyzed by1H NMR spectroscopy to determine the comprehensive metabolic change in these cultures during sucrose starvation. The amount
of sucrose, glucose, and fructose in the cells decreased to almost nothing after 12 h of culture in medium without sucrose.
In contrast, the total free amino acid content of the cells increased as the culture proceeded. Among the free amino acids,
phenylalanine and malic acid increased the most, followed by asparagine and alanine, whereas glutamic acid did not change
significantly. These results are in agreement with previous studies using HPLC.1H NMR spectroscopy enabled measurement of changes in the sugar and free amino acid content of whole cell extracts without
fractionation and complicated sample preparation. These results indicate that comprehensive metabolic changes in the cells
can be determined by a simple, rapid method using whole cell extracts and1H NMR spectroscopy. 相似文献
10.
Ian N. Roberts Donald A. MacKenzie David J. Jeenes David B. Archer Sheena E. Radford Carol V. Robinson Robin T. Aplin Christopher M. Dobson 《Biotechnology letters》1992,14(10):897-902
Summary
Aspergillus niger has been used as a host organism for the production of15N-labelled hen egg white lysozyme (HEWL). In order to achieve maximum incorporation of label, strains expressing the HEWL gene were grown in medium containing ammonium15N chloride as sole nitrogen source. Yields of HEWL protein were reduced relative to those obtained on more complex media. Gains in yield using complex media were offset by reduction in15N incorporation. No differences in either yield or kinetics of production were observed when ammonium15N chloride was replaced by unlabelled ammonium chloride as sole nitrogen source. Yields of15N-HEWL produced in this way are adequate for, and offer considerable advantages to, NMR studies of structure and folding of mutant and wild-type lysozymes. 相似文献
11.
Our goal was to establish the hydrophilic metabolome of heterotrophic Arabidopsis thaliana cells grown in suspension, a cellular model of plant sink tissues. Water‐soluble metabolites were extracted using four protocols: perchloric acid, boiling ethanol, methanol and methanol/chloroform (M/Chl). They were detected and quantified using 1H nuclear magnetic resonance (NMR) spectroscopy at 400 MHz. Extraction yields and reproducibility of the extraction methods were investigated. The effects of cell harvest protocol, cell grinding and lyophilization and storage conditions on the measured metabolic profiles were also studied. These quantitative studies demonstrated for the first time that the four extraction protocols commonly used do lead to quite similar molecular compositions as analyzed by 1H NMR. The M/Chl method proved effective and reliable to prepare series of physiologically significant extracts from plant cells for 1H NMR analysis. Reproducibility of the detected metabolome was assessed over long periods of time by analyzing a large number of separate extracts prepared from independent cultures. Larger variations in the NMR metabolite profiles could be correlated to changes in physiological parameters of the culture medium. Quantitative resolved 1H NMR of cell extracts proved to be robust and reliable for routine metabolite profiling of plant cell cultures. 相似文献
12.
In VivoP NMR Spectroscopic Studies of Soybean Bradyrhizobium Symbiosis: I. Optimization of Parameters
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31P NMR spectroscopy was used to study in vivo the symbiotic state established between soybean (Glycine max [L.] Merr. cv Williams) and Bradyrhizobium japonicum (USDA 110 and 138). Different experimental conditions were used to maintain perfused, respiring detached or attached nodules in an NMR magnet. The pH of the perfusion medium affected the cytoplasmic pH and the resolution of the spectra. The internal Pi content and distribution were assessed as a function of nodule age and green-house growth conditions and the rate of glucose and 2-deoxyglucose uptake into nodules in split and intact states. The major metabolites (glucose-6-P, fructose-1,6-diP, P-choline, Pi, NTP, UDP-glc, and NAD) were readily identified from 31P NMR spectra of perchloric acid extracts of nodules with the exception of one unknown phosphorus metabolite. Nodules stressed by glucose deprivation demonstrated movement of Pi between the vacuole and cytoplasmic compartments not previously observed in 31P NMR studies. 相似文献
13.
I. Basnak A. Balkan P. L. Coe R. T. Walker 《Nucleosides, nucleotides & nucleic acids》2013,32(1-3):177-196
Abstract 5-Alkyl(cycloalkyl)-2′-deoxyuridines VIa-VIf were synthesised in high yields by condensation of the corresponding silylated bases with 2-deoxy-3,5-di O-p-toluoyl-D-erthro-pentosyl chloride in chloroform and subsequent deblocking with sodium methoxide in methanol. The β-configuration, anti-glycosidic conformation and C2′-endo (S) sugar pucker of all of these compounds has been established from their 1H NMR, 13C NMR, UV and mass spectra. Under the same conditions, the condensation of silylated 5,6-trimethyleneuracil, resulted in 1:2/α:β anomeric mixture (overall yield 71%) and syn-conformation of the 5,6-trimethylene-2′-deoxyuridine [Xg]. The results of the condensation of the silylated 5,6-dimethyluracil are discussed as well. No significant antiviral activity has been found in testing the synthesised compounds against a range of herpes, influenza and HIV-1 viruses. 相似文献
14.
Ding Huang Wen-Juan Peng Qian Ye Xu-Ping Liu Liang Zhao Li Fan Kang Xia-Hou Han-Jing Jia Jian Luo Lin-Ting Zhou Bei-Bei Li Shi-Lei Wang Wen-Ting Xu Ze Chen Wen-Song Tan 《PloS one》2015,10(11)
Development of serum-free suspension cell culture processes is very important for influenza vaccine production. Previously, we developed a MDCK suspension cell line in a serum-free medium. In the present study, the growth kinetics of suspension MDCK cells and influenza virus production in the serum-free medium were investigated, in comparison with those of adherent MDCK cells in both serum-containing and serum-free medium. It was found that the serum-free medium supported the stable subculture and growth of both adherent and suspension cells. In batch culture, for both cell lines, the growth kinetics in the serum-free medium was comparable with those in the serum-containing medium and a commercialized serum-free medium. In the serum-free medium, peak viable cell density (VCD), haemagglutinin (HA) and median tissue culture infective dose (TCID50) titers of the two cell lines reached 4.51×106 cells/mL, 2.94Log10(HAU/50 μL) and 8.49Log10(virions/mL), and 5.97×106 cells/mL, 3.88Log10(HAU/50 μL), and 10.34Log10(virions/mL), respectively. While virus yield of adherent cells in the serum-free medium was similar to that in the serum-containing medium, suspension culture in the serum-free medium showed a higher virus yield than adherent cells in the serum-containing medium and suspension cells in the commercialized serum-free medium. However, the percentage of infectious viruses was lower for suspension culture in the serum-free medium. These results demonstrate the great potential of this suspension MDCK cell line in serum-free medium for influenza vaccine production and further improvements are warranted. 相似文献
15.
《FEBS letters》1986,202(1):122-126
NMR spectroscopy is one of the few techniques which has the sensitivity to detect subtle changes to the surface chemistry of cells. It has previously been demonstrated that high resolution 1H NMR methods can distinguish tumour cells with the capacity to metastasise and this information appears to arise from a type of proteolipid in or attached to the plasma membrane. Here we report that the 1H NMR signal, which we have used to identify metastatic cells in rat tumours, is significantly reduced in intensity after cultured cells are treated with trypsin/EDTA. The long T2 relaxation value (⪢ 350 ms) observed in metastatic cells is absent after enzyme treatment. 2D scalar correlated NMR (COSY) spectra of these treated cells show that a cross peak normally associated with malignancy and metastatic disease is markedly reduced. These findings indicate that the plasma membrane lipid particle which generates the high resolution spectrum is directly affected by trypsin/EDTA. Alterations to the cell surface properties were also demonstrated in vivo since reduced numbers of metastases were observed in animals injected with enzyme-treated cells. The correlation between the absence of a long T2 relaxation value and the diminished numbers of metastases in animals suggests that the plasma membrane particle is involved in the metastatic process. 相似文献
16.
蛋白质溶液NMR结构测定的一些新进展 总被引:4,自引:0,他引:4
新的标记技术的进展和采用稀释的液晶作为溶剂以提供额外的结构信息,提高了核磁共振技术测定蛋白质溶液三维结构的精度,扩大了分子质量测定范围.目前已经利用多维 15N,13C,2H标记NMR测定了许多分子质量为30 ku左右的蛋白质溶液结构,这一上限可能还会被进一步提高. 相似文献
17.
The effect of deuteration on the 13C linewidths of U-13C, 15N 2D crystalline bacteriorhodopsin (bR) from Halobacterium salinarium, a 248-amino acid protein with seven-transmembrane (7TM) spanning regions, has been studied in purple membranes as a prelude to potential structural studies. Spectral doubling of resonances was observed for receptor expressed in 2H medium (for both 50:50% 1H:2H, and a more highly deuterated form) with the resonances being of similar intensities and separated by < 0.3 ppm in the methyl spectral regions in which they were readily distinguished. Line-widths of the methyl side chains were not significantly altered when the protein was expressed in highly deuterated medium compared to growth in fully protonated medium (spectral line widths were about 0.5 ppm on average for receptor expressed both in the fully protonated and highly deuterated media from the Cδ, Cγ1, and Cγ2 Ile 13C signals observed in the direct, 21-39 ppm, and indirect, 9-17 ppm, dimensions). The measured 13C NMR line-widths observed for both protonated and deuterated form of the receptor are sufficiently narrow, indicating that this crystalline protein morphology is suitable for structural studies. 1H decoupling comparison of the protonated and deuterated bR imply that deuteration may be advantageous for samples in which low power 1H decoupling is required. 相似文献
18.
Isomaro Yamaguchi Masaharu Miyamoto Hisakazu Yamane Nobutaka Takahashi Kenichi Fujita Mamoru Imanari 《Bioscience, biotechnology, and biochemistry》2013,77(10):2453-2454
13C NMR spectroscopy was applied to studying lysine biosynthesis in Corynebacterium glutamicum ATCC 21543, a lysine producing mutant. It was cultured in a medium containing [1-13C]glucose or [6–13C]glucose as the sole carbon source and the 13C NMR spectrum of the culture filtrate was measured. C labeling patterns of l-lysine produced were well explained by the putative metabolic pathways of the bacterium. Fixation of 13CO2 liberated from the labeled substrates and the operation of the tricarboxylate cycle in the fermentation were obviously observed. The dual operations of the classical diaminopimelate pathway and the diaminopimelate dehydrogenase bypath were supported. Calculation of the contribution ratios of the metabolic pathways was attempted. 相似文献
19.
K Seamon 《Biochemical and biophysical research communications》1979,86(4):1256-1265
The 250MHz NMR spectrum of the brain Ca2+-dependent regulator protein was examined in the absence of cations and in the presence of Ca2+ or Mg2+. The Ca2+-saturated regulator protein and Mg2+-saturated regulator protein exhibited several spectral differences in the aromatic and aliphatic regions of their spectra. Certain spectral changes observed to occur upon addition of metal ions are qualitatively similar to those which have been observed in the spectrum of skeletal troponin-C. These results suggest that the large sequence homology between skeletal troponin-C and the regulator protein results in similar conformational changes due to the binding of Ca2+ or Mg2+. 相似文献
20.
The effect of functional ingredients (carrot juice, whole soy flour, and whole kamut flour) and storage (180 days) on physicochemical
properties (texture and amylopectin recrystallization) and water status (moisture content, water activity, ice melting peak
thermal properties, and proton nuclear magnetic resonance (1H NMR) mobility) of tortillas has been studied. Different formulations significantly changed the parameters studied during
storage resulting in larger changes than in the standard formulation (STD) that, therefore, may be considered the most stable
product. The properties of whole kamut tortillas were very similar to those of standard sample while the formulation that
contained carrot juice lead to an increased system rigidity observable both at macroscopic (textural properties), macromolecular
(significantly reduced), and molecular (1H FID) levels. A decrease of moisture content, water activity, endothermic transition ~0 °C, and an increase of 1H NMR mobility (1H T2 pop A and C) were observed in soy-containing products [(soy enriched (SOY) and carrot, soy, and kamut (CSK)]. SOY and CSK
had very low water activity, presented the highest 1H NMR molecular mobility and underwent the most marked changes during storage suggesting that water activity cannot be taken
as a sole indicator of food stability as very important modifications occurred in tortillas at molecular level. 相似文献