Search

The KCNQ1 voltage-gated potassium channel regulates the repolarization of cardiac cells, and a plurality of point mutations in its voltage-sensing domain (VSD) are associated with toxic gain or loss of pore function, resulting in disease. As is the case with many disease-associated membrane proteins, there are hundreds of human variants of interest identified for KCNQ1; however, a significant portion of these variants have not been characterized in relation to their functional and disease associations. Additionally, as the VSD consists of four transmembrane helices, studies into dynamic structural differences among KCNQ1 VSD variants are hindered by the current limitations and deficits in the high-resolution structure determination of membrane proteins. Here, we use native ion mobility-mass spectrometry and collision-induced unfolding (CIU) to address the need for a high throughput-compatible method for the structural characterization of membrane protein variants of unknown significance using the KCNQ1 VSD as a model system. We perform CIU on wild-type and three mutant KCNQ1 VSD forms associated with the toxic gain or loss of function and show through both automated feature detection and comprehensive difference analysis of the CIU data sets that the variants are clearly grouped by function and disease association. We also construct a classification scheme based on the CIU data sets, which is able to differentiate the variant functional groups and classify a recently characterized variant to its correct grouping. Further, we probe the stability of the KCNQ1 VSD variants when liberated from C12E8 micelles at pH 8.0 and find preliminary evidence that the R231C mutation associated with the gain of the pore function is destabilized relative to the wild-type and loss of function variants.

How the distinctive lipid composition of mammalian plasma membranes impacts membrane protein structure is largely unexplored, partly because of the dearth of isotropic model membrane systems that contain abundant sphingolipids and cholesterol. This gap is addressed by showing that sphingomyelin and cholesterol-rich (SCOR) lipid mixtures with phosphatidylcholine can be co-solubilized by n-dodecyl-β-melibioside to form bicelles. Small angle X-ray and neutron scattering, as well as cryo-electron microscopy demonstrate that these assemblies are stable over a wide range of conditions and exhibit the bilayered-disc morphology of ideal bicelles even at low lipid-to-detergent mole ratios. SCOR bicelles are shown to be compatible with a wide array of experimental techniques, as applied to the transmembrane human amyloid precursor C99 protein in this medium. These studies reveal an equilibrium between low order oligomer structures that differ significantly from previous experimental structures of C99, providing an example of how ordered membranes alter membrane protein structure.

Membrane proteins represent most current therapeutic targets, yet remain understudied due to their insolubility in aqueous solvents and generally low yields during purification and expression. Ion mobility-mass spectrometry and collision induced unfolding experiments have recently garnered attention as methods capable of directly detecting and quantifying ligand binding within a wide range of membrane protein systems. Despite prior success, ionized surfactant often creates chemical noise patterns resulting in significant challenges surrounding the study of small membrane protein-ligand complexes. Here, we present a new data analysis workflow that overcomes such chemical noise and then utilize this approach to quantify and classify ligand binding associated with the 36 kDa dimer of translocator protein (TSPO). Following our denoising protocol, we detect separate gas-phase unfolding signatures for lipid and protoporphyrin TSPO binders, molecular classes that likely interact with separate regions of the protein surface. Further, a detailed classification analysis reveals that lipid alkyl chain saturation levels can be detected within our gas-phase protein unfolding data. We combine these data and classification schemes with mass spectra acquired directly from liquid-liquid extracts to propose an identity for a previously unknown endogenous TSPO ligand.

Peripheral myelin protein (PMP22) is an integral membrane protein that traffics inefficiently even in wild-type (WT) form, with only 20% of the WT protein reaching its final plasma membrane destination in myelinating Schwann cells. Misfolding of PMP22 has been identified as a key factor in multiple peripheral neuropathies, including Charcot-Marie-Tooth disease and Dejerine–Sottas syndrome. While biophysical analyses of disease-associated PMP22 mutants show altered protein stabilities, leading to reduced surface trafficking and loss of PMP22 function, it remains unclear how destabilization of PMP22 mutations causes mistrafficking. Here, native ion mobility–mass spectrometry (IM-MS) is used to compare the gas phase stabilities and abundances for an array of mutant PM22 complexes. We find key differences in the PMP22 mutant stabilities and propensities to form homodimeric complexes. Of particular note, we observe that severely destabilized forms of PMP22 exhibit a higher propensity to dimerize than WT PMP22. Furthermore, we employ lipid raft–mimicking SCOR bicelles to study PMP22 mutants, and find that the differences in dimer abundances are amplified in this medium when compared to micelle-based data, with disease mutants exhibiting up to 4 times more dimer than WT when liberated from SCOR bicelles. We combine our findings with previous cellular data to propose that the formation of PMP22 dimers from destabilized monomers is a key element of PMP22 mistrafficking.

Luminescent Eu:GdVO nanoparticles, with an average size of 60 nm, were deposited first on monocrystalline silicon wafers, then on four different natural stone materials, by a spray-coating technique and a silica layer was subsequently deposited by atmospheric pressure plasma jet to protect the luminescent layer and improve its adhesion to the substrate. The luminescent films were characterized by photoluminescence excitation and emission, while the surface morphology was examined by FEG-SEM microscopy and spectroscopic ellipsometry to determine the coating thickness. The optical appearance of the coatings was also evaluated by colorimetric measurements and the efficacy of the fixing action of the silica layer was estimated by PL measurements performed before and after a Scotch™ tape peeling test. The proposed methodology, easily applied on the surface of stone supports, has led to the realization of a luminescent film displaying good mechanical properties, transparent and undetectable in the presence of visible light, but easily activated by UV light source, indicating that the Eu:GdVO nanophosphors could be used as luminescent nanotags for a reliable anti-counterfeiting technology., Ca' Foscari University of Venice and Consortium INSTM are acknowledged for financial support. Dr. Alessandro Patelli, coordinator of the PANNA European Project (Grant Agreement No 282998) is acknowledged for having inspired the identification marker applicability.

A ferrugem polissora, causada por Puccinia polysora Underw. é uma das doenças mais destrutivas da cultura do milho, ocorrendo em importantes áreas de produção desta cultura no Brasil. A principal forma de controle desta doença é o uso de cultivares resistentes, havendo no mercado um grande número de cultivares com diferentes graus de resistência. O objetivo deste trabalho foi avaliar a reação de cultivares comerciais de milho quanto à resistência à ferrugem polissora, em diferentes localidades no Estado de São Paulo, correlacionando com a produtividade. Foram avaliados 50 híbridos simples e triplos (HST) e 22 híbridos duplos e variedades de milho (HDV) em uso pelos agricultores no ano agrícola 2005/2006 quanto à sua reação à ferrugem polissora em seis locais nas regiões oeste e centro-norte do Estado de São Paulo. Nos experimentos com HST, as cultivares mais resistentes e que tiveram as maiores produtividades foram: 30F80, 30F90, 30K73, AG 7000, DAS 2B710, DKB 191, DKB 466 e Impacto. Dentre os HDV, destacaram-se como as mais resistentes e apresentando as maiores produtividades: 30S40 e AG 2040. A redução de produtividade em função da severidade da ferrugem polissora, avaliada no estádio de grãos pastosos, variou de 3,5% para cultivares com aproximadamente 2,5% de área foliar afetada a 20,3% para cultivares com, em média, 39% de área foliar afetada, em relação às cultivares com maior resistência à doença (1,4% de área foliar afetada).Southern rust, caused by Puccinia polysora Underw., has become one of the most destructive diseases affecting maize, occurring in important areas of production of this crop in Brazil. Using resistant cultivars is the most efficient means to control this disease, and there are a large number of cultivars with different resistance degrees in the market. The aim of this study was to evaluate the reaction of commercial maize cultivars for resistance to southern rust in different localities of São Paulo State, correlated to yield. A total of 50 simple and triple hybrids (HST) and 22 double hybrids and varieties of maize (HDV) in use by farmers were evaluated in 2005/2006 for their reaction to southern rust in six locations in western and north-central regions of São Paulo State. In the experiments with HST, the most resistant cultivars with the highest yields were: 30F80, 30F90, 30K73, AG 7000, DAS 2B710, DKB 191, DKB 466 and Impacto. Among HDV, the most resistant ones presenting the highest yields were: 30S40 and AG 2040. Yield losses due to the severity of southern rust, assessed in the stage of pastry grain, ranged from 3.5%, for cultivars with approximately 2.5% of leaf area affected by the disease, to 20.3% for cultivars with 39% of the leaf area affected, compared to cultivars of higher resistance to the disease (1.4% affected leaf area).

Eu:GdVO nanophosphorswith an average size of 60 nm, synthesized by a facile solvothermalmethod, were deposited on monocrystalline silicon wafers by a spray-coating technique with artworks anti-counterfeiting applications in mind. Atmospheric pressure plasma jet (APPJ) was used to deposit a silica-based layer on top of the nanometric luminescent layer, in order to improve its adhesion to the substrate and to protect it from the environment. The nanophosphors were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Coating composition was investigated by Fourier transform infrared spectroscopy (FT-IR) and its morphology was characterized by scanning electron microscopy (FEG-SEM). The film thickness was evaluated by means of ellipsometry and adhesionwas estimated by a peeling test. Luminescent properties of the nanophosphors deposited and fixed on silicon wafers were also measured. The whole layer resulted well-adhered to the silicon substrate, transparent and undetectable in the presence of visible light, but easily activated by UV light source., Università Ca' Foscari Venezia and Consortium INSTM are acknowledged for the financial support.

During the past 20 years, numerous stellar streams have been discovered in both the Milky Way and the Local Group. These streams have been tidally torn from orbiting systems, which suggests that most should roughly trace the orbit of their progenitors around the Galaxy. As a consequence, they play a fundamental role in understanding the formation and evolution of our Galaxy. This project is based on the possibility of applying a technique developed by Binney to various tidal streams and overdensities in the Galaxy. The aim is to develop an efficient method to constrain the Galactic gravitational potential, to determine its mass distribution, and to test distance measurements. Here we apply the technique to the Grillmair & Dionatos GD-1 cold stellar stream. In the unrealistic case of noise-free data, the results show that the technique provides excellent discrimination against incorrect potentials and that it is possible to predict the heliocentric distance very accurately. This changes dramatically when errors are taken into account, which wash out most of the results. Nevertheless, it is still possible to rule out spherical potentials and set constraints on the distance of a given stream.

The direct detection of dark matter on Earth depends crucially on its density and its velocity distribution on a milliparsec scale. Conventional N-body simulations are unable to access this scale, making the development of other approaches necessary. In this paper, we apply the method developed in Fantin et al. 2008 to a cosmologically-based merger tree, transforming it into a useful instrument to reproduce and analyse the merger history of a Milky Way-like system. The aim of the model is to investigate the implications of any ultra-fine structure for the current and next generation of directional dark matter detectors. We find that the velocity distribution of a Milky Way-like Galaxy is almost smooth, due to the overlap of many streams of particles generated by multiple mergers. Only the merger of a 10^10 Msun analyse can generate significant features in the ultra-local velocity distribution, detectable at the resolution attainable by current experiments.

Inks and paper are the main materials and components of library and archive collections. Since the Third century B.C. there has been a continual succession of ink recipes from all over the world, with varying levels of documentation of the recipes used; however, it was only in the 19th century that Europe became the main producer and industrial leader in the discovery of new products. The aim of this study is to find out more about this last historical period, when new inks were created that had never been known or used in the past. In this study we chose four inks: they belong to documents preserved in the archive of the Superintendence Beni architettonici per il paesaggio e per il patrimonio storico artistico ed etnoantropologico (BAPPDAD) of Venice Lagoon, held in the Palazzo Ducale (Ducal Palace) of Venice. Fourier Transform Infrared Spectroscopy (ATR), Scanning Electron Microscopy (SEM-EDS) and pyrolysis coupled to a gas chromatograph with mass spectrometric detector (Py–GC–MS) allowed us to obtain a qualitative characterization of organic and inorganic elements in three different ink typologies.

Different deposition methods of nanocomposite silica films with embedded Y2O3:Eu3 +, Tb3 + by atmospheric pressure plasma jet (APPJ) technology are presented. We found that a two-step strategy consisting in the APPJ deposition of a silica film on previously deposited nanophosphors is a very efficient method to obtain nanocomposite coatings with excellent adhesion to the substrate. Moreover the APPJ deposited silica film ensures protection of the luminescent nanoparticles and preserves the photoluminescence emission properties of the nanophosphors. Optically active coatings can be therefore deposited by using this technology.

Multiple system atrophy (MSA) is a neurodegenerative disorder characterized by a progressive degeneration of the striatonigral, olivo-ponto-cerebellar, and autonomic systems. Glial cytoplasmic inclusions (GCIs) containing alpha-synuclein represent the hallmark of MSA and are recapitulated in mice expressing alpha-synuclein in oligodendrocytes. To assess if oligodendroglial expression of human wild-type alpha-synuclein in mice (proteolipid promoter, PLP-SYN) could be associated with age-related deficits, PLP-SYN and wild-type mice were assessed for motor function, brain morphometry, striatal levels of dopamine and metabolites, dopaminergic loss, and distribution of GCIs. PLP-SYN displayed age-related impairments on a beam-traversing task. MRI revealed a significantly smaller brain volume in PLP-SYN mice at 12 months, which further decreased at 18 months together with increased volume of ventricles and cortical atrophy. The distribution of GCIs was reminiscent of MSA with a high burden in the basal ganglia. Mild dopaminergic cell loss was associated with decreased dopamine turnover at 18 months. These data indicate that PLP-SYN mice may recapitulate some of the progressive features of MSA and deliver endpoints for the evaluation of therapeutic strategies.

Faint fuzzies are metal-rich apparently-old star clusters with unusually large radii (7-15 pc), found mostly in S0 galaxies, whose source remain obscure. To identify their origins, we compare planetary nebulae and neutral hydrogen with faint fuzzy positions and line-of-sight velocities in NGC1023. In this way, we rule out scenarios in which these objects are associated with an on-going merger or with a spheroid population in NGC1023. Their kinematics are indistinguishable from the stellar disk population in this galaxy, and we conclude that faint fuzzies are most likely just remnant open clusters. Their observed association with S0s then simply reflects the difficulty of identifying such objects in later-type disk galaxies., Comment: A&A accepted, 4 pages, 2 Figures

Dark matter plays a fundamental role in theories of formation and evolution of galaxies, so every attempt to model galaxy formation and evolution has to consider the presence of dark halos. Moreover, mergers and accretions appear to be fundamental driving mechanisms in determining the present day properties of galaxies. Our project studies the ultra‐fine distribution of dark matter in the Milky Way and the implications for the next generation of dark matter particle detectors. We have developed a model for halo mergers in a Milky Way‐like galaxy. The signals expected in the lab‐based dark matter detection experiments depend on the phase‐space distribution on submilliparsec scales: with our numerical technique it is possible to resolve structures, produced by mergers of subhalos with a larger parent halo, inaccessible to conventional N‐body simulations. When applied in a cosmological context, this method becomes a powerful instrument to reproduce and analyse the complete multiple merger history of a Milky ...

Inks and paper are the main materials and components of library and archive collections. Since the Third century B.C. there has been a continual succession of ink recipes from all over the world, with varying levels of documentation of the recipes used; however, it was only in the 19th century that Europe became the main producer and industrial leader in the discovery of new products. The aim of this study is to find out more about this last historical period, when new inks were created that had never been known or used in the past. in this study we chose four inks: they belong to documents preserved in the archive of the Superintendence Beni architettonici per il paesaggio e per il patrimonio storico artistico ed etnoantropologico (BAPPDAD) of Venice Lagoon, held in the Palazzo Ducale (Ducal Palace) of Venice. Fourier Transform Infrared Spectroscopy (ATR), Scanning Electron Microscopy (SEM-EDS) and pyrolysis coupled to a gas chromatograph with mass spectrometric detector (Py-GC-MS) allowed us to obtain a qualitative characterization of organic and inorganic elements in three different ink typologies. (C) 2008 Elsevier B.V. All rights reserved.

Inks and paper are the main materials and components of library and archive collections. Since the beginning of paper and ink production empirical recipes have been followed, but in the 19th century with the transformation of Europe during the Industrial Revolution, the continent became the main leader for the discovery of new products and new industrial production processes. The aim of this study is to shed light on paper and ink production processes during this key historical period. In this study we have chosen some documents preserved in the archive of the Soprintendenza dei Beni Architettonici e Paesaggistici (B.A.P.) di Venezia e Laguna, held in the Palazzo Ducale (Ducal Palace) of Venice. Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FT-IR), and inductively coupled plasma-mass spectrometry (ICP-MS) allowed us to obtain a qualitative and quantitative characterization of the organic and inorganic components in both paper and inks. Cluster analysis and principal component analysis (PCA) were employed for statistical analysis of the results.

The paper manufacturing process remained unchanged for many centuries, until, in the nineteenth century, the crisis of rags led industrialized countries to patent new production processes with different raw materials. This study deals with this period of transition by analyzing four samples stored at the archives of Superintendency Beni Architettonici per il Paesaggio e per il Patrimonio Storico Artistico ed Etnoantropologico (BAPPDAD) of Venice Lagoon, based in the Palazzo Ducale. The samples were analyzed by FT-IR (ATR), SEM-EDS, HPLC-MS/MS and Py-GC/MS. These techniques allow the characterization of various raw materials and adhesives used in various stages of paper production. These analyses have found a gradual introduction of ground wood in the composition of papers from the mid-nineteenth century, and the use of rosin as glue only in more recent documents.

Various laboratory-based experiments are underway attempting to detect dark matter directly. The event rates and detailed signals expected in these experiments depend on the dark matter phase space distribution on sub-milliparsec scales. These scales are many orders of magnitude smaller than those that can be resolved by conventional N-body simulations, so one cannot hope to use such tools to investigate the effect of mergers in the history of the Milky Way on the detailed phase-space structure probed by the current experiments. In this paper we present an alternative approach to investigating the results of such mergers, by studying a simplified model for a merger of a sub-halo with a larger parent halo. With an appropriate choice of parent halo potential, the evolution of material from the sub-halo can be expressed analytically in action-angle variables, so it is possible to obtain its entire orbit history very rapidly without numerical integration. Furthermore by evolving backwards in time, we can obtain arbitrarily-high spatial resolution for the current velocity distribution at a fixed point. Although this model cannot provide a detailed quantitative comparison with the Milky Way, its properties are sufficiently generic that it offers qualitative insight into the expected structure arising from a merger at a resolution that cannot be approached with full numerical simulations. Preliminary results indicate that the velocity-space distribution of dark matter particles remains characterized by discrete and well-defined peaks over an extended period of time, both for single and multi-merging systems, in contrast to the simple smooth velocity distributions sometimes assumed in predicting laboratory experiment detection rates., 6 pages, 6 figures, accepted for publication in MNRAS

Nocistatin (NST) is a neuropeptide generated from cleavage of the nociceptin/orphanin FQ (N/OFQ) precursor. Evidence has been presented that NST acts as a functional antagonist of N/OFQ, although NST receptor and transduction pathways have not yet been identified. We previously showed that N/OFQ inhibited [(3)H]5-hydroxytryptamine ([(3)H]5-HT) release from mouse cortical synaptosomes via activation of NOP receptors. We now investigate whether NST regulates [(3)H]5-HT release in the same preparation.Mouse and rat cerebrocortical synaptosomes in superfusion, preloaded with [(3)H]5-HT and stimulated with 1 min pulses of 10 mM KCl, were used.Bovine NST (b-NST) inhibited the K(+)-induced [(3)H]5-HT release, displaying similar efficacy but lower potency than N/OFQ. b-NST action underwent concentration-dependent and time-dependent desensitization, and was not prevented either by the NOP receptor antagonist [Nphe(1) Arg(14),Lys(15)]N/OFQ(1-13)-NH(2) (UFP-101) or by the non-selective opioid receptor antagonist, naloxone. Contrary to N/OFQ, b-NST reduced [(3)H]5-HT release from synaptosomes obtained from NOP receptor knockout mice. However, both N/OFQ and NST were ineffective in synaptosomes pre-treated with the G(i/o) protein inhibitor, Pertussis toxin. NST-N/OFQ interactions were also investigated. Co-application of maximal concentrations of both peptides did not result in additive effects, whereas pre-application of maximal b-NST concentrations partially attenuated N/OFQ inhibition.We conclude that b-NST inhibits [(3)H]5-HT release via activation of G(i/o) protein linked pathways, not involving classical opioid receptors and the NOP receptor. The present data strengthen the view that b-NST is, per se, a biologically active peptide endowed with agonist activity.

Lower Troncoso Member is one of the most important reservoirs within the Neuquen Basin, Argentina, where it hosts large amounts of reserves.

The presence of endocrine cells was investigated by immunocytochemical procedures in the gut and salivary gland of Viviparus ater, a freshwater prosobranch gastropod. The endocrine cells were scanty and both of closed and open cell type. Most of them were located in the esophagus (immunostaining with anti-gastrin, anti-insulin, anti-serotonin and anti-substance P antisera), very few in the stomach (immunoreactive only to anti-gastrin antibody) and in proximal part of the intestine (immunoreactive to anti-serotonin and anti-substance P antibodies). In the salivary glands, occasional endocrine cells scattered among the glandular cells in the adenomera stained with anti-neuropeptide Y, anti-pancreatic polypeptide and anti-somatostatin sera were detected.

Resume Des recherches preliminaires indiquent l'existence de lipides dans la cellule glandulaire gastrique de 23 especes d'oiseaux. Dans le developpement du poulet et du pigeon les lipides sont demonstrables des le commencement de l'alimentation.

The influence of amiodarone on contractions induced by acetylcholine (ACh) was studied in isolated preparations of guinea-pig ileum, duodenum and stomach fundus as well as in rat stomach fundus. In the guinea-pig ileum a concentration-dependent antispasmodic effect of amiodarone (20-70 microM) was observed after 30 min exposure to the drug, but not after 15 min. The inhibition of ACh-induced contraction further increased with time after removal of amiodarone from the bathing fluid. Similar results were obtained in ileum preparations maintained in a low Ca2+ medium (0.35 mM CaCl2) and under these conditions the response to ACh was restored by washing the tissue with a normal Ca2+ medium (1.4 mM CaCl2). Both low Ca2+ and amiodarone depressed the tonic component of ACh-induced contraction more than the phasic one. Guinea-pig duodenum was more susceptible than the ileum to the antispasmodic action of amiodarone and again this effect was slow in onset and not reversible. The highest inhibition of ACh-induced contractions by amiodarone was obtained in guinea-pig stomach fundus. In these preparations treated with a low amiodarone concentration (20 microM) the response to ACh was restored after drug removal. In rat stomach fundus the effect of amiodarone was low and not reversible. Like amiodarone, Ca2+ lowering caused a decrease in the response to ACh with the following order of effectiveness: guinea-pig stomach greater than guinea-pig duodenum greater than guinea-pig ileum greater than rat stomach. The inhibitions caused by amiodarone and by low Ca2+ were always additive. These results indicate that amiodarone exerts an antispasmodic effect on the gastrointestinal tract and that regional and species differences exist for this action. The possible involvement of Ca2+ in this effect is discussed.