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61.
Paolo Bigini Fabrizio Gardoni Sara Barbera Alfredo Cagnotto Elena Fumagalli Annalisa Longhi Massimiliano M Corsi Monica Di Luca Tiziana Mennini 《BMC neuroscience》2006,7(1):71
Background
The localisation of AMPA and NMDA receptor subunits was studied in a model of degeneration of cervical spinal motoneurons, the wobbler mouse. Cervical regions from early or late symptomatic wobbler mice (4 or 12 weeks of age) were compared to lumbar tracts (unaffected) and to those of healthy mice. 相似文献62.
M. Francesca Ottaviani Annalisa Geniali Michela Cangiotti Filippo Mangani 《Research on Chemical Intermediates》2002,28(2-3):117-130
Mastic resin used as a covering film for painting protection was analyzed by electron paramagnetic resonance (EPR) spectroscopy, both as received and upon aging in sun-light. The effect of prolonged exposure to sun-light was mimicked by UV and, more so, by xenon lamp irradiation. Solid mastic presented EPR signals due to radicals trapped by PBN in solution. Data in the literature indicated the formation of acyl radicals (RCO·). These radicals preferentially dissolved in medium polarity solvents. The radical concentration in the solid mastic increased over time more than 50 times upon UV irradiation for 96 h and, even more, by xenon irradiation for 800 h. Also the PBN-trapped radicals in solution increased in concentration by irradiation. Small nitroxide radicals (TEMPO) interacted with a polar fraction of mastic dissolved in methanol, but mainly interacted with low polar mastic molecules in hydrophobic solvents. It was suggested, on the basis of both the PBN-spin trapping data and the TEMPO mobility variation in the solvents at different polarities, that terpenoid molecules partially polymerize by a radical mechanism to form low molecular weight products. A polyaromatic-radical (pyrene-TEMPO) and a biomolecule-radical (doxylcholestane) both interact weakly with mastic molecules in cyclohexane solutions. A positively charged surfactant radical (dimethylammonium-TEMPO bromide) was easily adsorbed onto the solid mastic surface suggesting that detergents are responsible for mastic degradation. In conclusion, this study provided information on the degradation mechanism of mastic resin and on its interacting ability towards external molecules and pollutants. 相似文献
63.
Ambrosi G Formica M Fusi V Giorgi L Guerri A Lucarini S Micheloni M Paoli P Rossi P Zappia G 《Inorganic chemistry》2005,44(9):3249-3260
The synthesis and characterization of new polydentate ligand 2-(N),2'-(N')-bis[2-(3-hydroxy-2-oxo-2H-pyridin-1-yl)acetamido]-1(N'),2(N),2'(N')-trimethyl-2,2'-diaminodiethylamine (L3) is reported. The coordination properties of L3 and of two analogous macrocyclic ligands (L1 and L2) toward Cu(II) and Zn(II) metal ions are reported. All three ligands show the 3-hydroxy-2(1H)-pyridinone (HPO) groups attached as sidearms to a polyaza fragment, which is a macrocyclic framework in the case of L1 and L2 while it is an open chain in the case of L3. The role of the polyaza fragments in preorganizing the two sidearms was investigated. The basicity of L3 and the binding properties of L1-L3 were determined by means of potentiometric measurements in aqueous solution (298.1 +/- 0.1 K, I = 0.15 mol dm(-3)). UV-vis spectra as well 1H and 13C NMR experiments were used to understand the role of the HPO and of the polyaza fragments in the stabilization of the cations. While L1 forms stable mono- and dinuclear complexes, L2 and L3 can form only mononuclear species with each of the metal ions investigated. In the main mononuclear species of L2 and L3, the two HPO moieties stabilize the M(II) in a square planar geometry due to the two oxygen atoms of each HPO. The coordination sphere of the metal is completed by adding a secondary ligand such as water molecules in the case of Cu(II) systems or OH- in the Zn(II) systems. These results are confirmed by the crystal structures of the [CuH(-1)L2]+ and [CuH(-1)L3]+ species reported herein. Two conformations of L1 can be hypothesized in the formation of the dinuclear species, as suggested by NMR experiments on the [ZnH(-2)L1] species, which shows two conformers slowly interchanging on the NMR time scale, one of which was found to be more insoluble. 相似文献
64.
Magnani A Barbucci R Lamponi S Chiumento A Paffetti A Trabalzini L Martelli P Santucci A 《Electrophoresis》2004,25(14):2413-2424
Plasma protein adsorption patterns on surfaces may give vital information to evaluate biocompatibility of biomaterials designed for direct blood-contacting applications or tissue integration. Adsorption of human serum proteins on four different types of biomaterials (glass, aminosilanized glass, hyaluronan and sulfated hyaluronan) was analyzed by two-dimensional electrophoresis. Desorption of proteins from the surfaces was first classically achieved by sodium dodecyl sulfate (SDS) elution. We introduced a second elution step (by use of isoelectric focusing (IEF) sample buffer consisting of urea, 3-[(3-cholamidopropyl)dimethylammonio]-1-propansulfonate, and dithioerythritol) which allows more stringent elution conditions and is a tool to evaluate the protein adsorption strength to biomaterials. Moreover, the two-step elution may discriminate between irreversible and reversible adsorption of plasma proteins for biomaterials, thus helping to elucidate the structure of protein multilayers which form a complex system at the surfaces. The IEF sample buffer proved not to alter the biomaterial structure and integrity. Hydrophobic bonds resulted to be the main strength driving protein adsorption onto our biomaterials. Apolipoproteins were the most important proteins interacting with the surfaces suggesting that high-density lipoprotein (HDL) particles could play a role in biocompatibility due to their beneficial effects on endothelial cells. 相似文献
65.
Antonino Lauria Annalisa Guarcello Gabriella Macaluso Anna Maria Almerico 《Tetrahedron letters》2009,50(52):7333-1004
The reactivity of asymmetric benzo-condensed diazines in the 1,3-dipolar cycloaddition reactions with nitrilimines was investigated. The results demonstrated that, at variance with the symmetric quinoxaline, a certain grade of diastereoselectivity emerged. Moreover in the case of the 5-methylquinoxaline and quinazoline a mono-cycloadduct was obtained. 相似文献
66.
67.
Manet I Manoli F Donzello MP Viola E Andreano G Masi A Cellai L Monti S 《Organic & biomolecular chemistry》2011,9(3):684-688
A water soluble Zn(II) porphyrazine drives the conformational equilibrium of the G-quadruplex of a human telomeric sequence exclusively towards a parallel conformation upon complexation. 相似文献
68.
69.
Fabio Mastrogiovanni Loredana Basiricò Umberto Bernabucci Margherita Campo Annalisa Romani 《Natural product research》2020,34(10):1465-1469
AbstractPomegranate peel extracts (PPE) were tested for the first time on BME-UV1, a valid cellular model to study the bovine mammary epithelial metabolism, to evaluate the effects on the oxidative stress and inflammatory status. Based on the statistical analysis of MTT data, PPE at 0.1, 1.0 and 10?μg/mL resulted not cytotoxic after 24?h, 48?h and 7 days of treatment. At the same concentrations, PPE induced a reduction of ROS production elicited by the addition of hydrogen peroxide or lipopolysaccharide evidencing an antioxidant effect confirmed also by a decrease of malondialdehyde. At 10?μg/mL, PPE reduced pro-inflammatory cytokines expressions showing an anti-inflammatory effect on BME-UV1 treated with lipopolysaccharide. Although in vivo experiments are necessary, the results of this study are promising for future applications of PPE as feed supplement for dairy cattle, in particular around calving, when the animals are more subject to oxidative stress and inflammatory diseases. 相似文献
70.
Adrover M Esposito V Martorell G Pastore A Temussi PA 《Journal of the American Chemical Society》2010,132(45):16240-16246
All globular proteins undergo transitions from their native to unfolded states if exposed either to cold or to heat perturbation. While the heat-induced transition is well described for a large number of proteins, in media compatible with natural environments, the limited number of examples of cold denatured states concern proteins artificially destabilized, for instance, by the presence of denaturants, ad hoc point mutations, or both. Here, we provide a characterization of the low temperature unfolded state of Yfh1, a natural protein that undergoes cold denaturation around water freezing temperature, in the absence of any denaturant. By achieving nearly full assignment of the NMR spectrum, we show that at -1 °C, Yfh1 has all the features of an unfolded protein, although retaining some local, residual secondary structure. The effect is not uniform along the sequence and does not merely reflect the secondary structural features of the folded species. The N-terminus seems to be dynamically more flexible, although retaining some nascent helix character. Interestingly, this region is the one containing functionally important hot-spots. The β-sheet region and the C-terminal helix are completely unfolded, although experiencing some conformational exchange, partly due to the presence of several prolines. Ours is the first step toward a full characterization of the low temperature unfolded state of a natural protein, reached without the aid of any destabilizing agent. We discuss the implications of our findings for understanding cold denatured states. 相似文献