117 research outputs found

    Vaccinia virus immunomodulator A46 : a lipid and protein-binding scaffold for sequestering host TIR-domain proteins

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    TS received Austrian Science Fund (FWF) grants P24038, W1221 and W1258. GAB is a member of Max F. Perutz Laboratories and the Vienna International PostDoctoral Program (VIPS). TKS is a holder of Wellcome Trust grant 097831. IU has Spanish Ministry of Economy and Competitiveness grant BIO2013-49604-EXP.Vaccinia virus interferes with early events of the activation pathway of the transcriptional factor NF-kB by binding to numerous host TIR-domain containing adaptor proteins. We have previously determined the X-ray structure of the A46 C-terminal domain; however, the structure and function of the A46 N-terminal domain and its relationship to the C-terminal domain have remained unclear. Here, we biophysically characterize residues 1-83 of the N-terminal domain of A46 and present the X-ray structure at 1.55 Å. Crystallographic phases were obtained by a recently developed ab initio method entitled ARCIMBOLDO_BORGES that employs tertiary structure libraries extracted from the Protein Data Bank; data analysis revealed an all β-sheet structure. This is the first such structure solved by this method which should be applicable to any protein composed entirely of β-sheets. The A46(1-83) structure itself is a β-sandwich containing a co-purified molecule of myristic acid inside a hydrophobic pocket and represents a previously unknown lipid-binding fold. Mass spectrometry analysis confirmed the presence of long-chain fatty acids in both N-terminal and full-length A46; mutation of the hydrophobic pocket reduced the lipid content. Using a combination of high resolution X-ray structures of the N-and C-terminal domains and SAXS analysis of full-length protein A46(1-240), we present here a structural model of A46 in a tetrameric assembly. Integrating affinity measurements and structural data, we propose how A46 simultaneously interferes with several TIR-domain containing proteins to inhibit NF-κB activation and postulate that A46 employs a bipartite binding arrangement to sequester the host immune adaptors TRAM and MyD88.Publisher PDFPeer reviewe

    Development and Implementation of a Machine to Increase the Production and the Quality of a Compost

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    The composting sector plays a crucial role in the urban waste management system and is essential for advancing towards a circular economy. All organic matter can be entirely recovered from waste collection, except for the extraneous fractions present as impurities. In the studied waste composting plant, three fractions are produced: >50 mm (waste not idoneous for compost), <12 mm (suitable for compost market) and 50-12 mm (overflow). The latter is used as inoculum and therefore recirculates many times, reducing the sizes of its constituents, which are mainly plastic films falling into the lower class <12 mm, where they are concentrated. The goal of this study is to reduce the quantity of undesirable materials present in the 50-12 mm class in order to increase the quality of the compost produced. For this reason, a compost characterization was carried out and a plant solution was proposed: the inclusion of a mesh conveyor belt, with beater rollers and an aspiration system at the end. The fine organic material passes through the mesh sieve, and it is moved apart from the overflow material, in which the light plastics are aspirated. More than 10% of the overflow weight is recovered as clean compost, with very low percentages of undesired remaining. A reduction in plastic impurity of 75% is reached

    The use of SDMT Data for Local Seismic Response Studies in the Catania Area

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    Soil stiffness at small strain is a key parameter to solve many geotechnical problems, such as the design of the foundation and the knowledge of the seismic behaviour. There are many methods to perform in-situ soil shear wave velocity measurements: Down Hole test (D-H), Cross Hole test (C-H), Spectral Analysis of Surface Waves (SASW), Multichannel Analysis of Surface Waves (MAWS), etc. Among these methods, the use of Seismic Dilatometer Marchetti Tests (SDMT) to measure the shear wave velocity profile was developed and used in Italy. This test shows good repeatability of the measurements and the possibility to know, at the same time, the mechanical soil characteristics in the static field. In order to evaluate the soil profile of shear wave velocity (Vs), deep site investigations have been undertaken in some Italian sites, prone to high seismic risk. C-H and D-H tests, SDMT and Noise Analysis Surface Waves (NASW) have been carried out. In this paper, the relevance of using the Seismic Dilatometer Marchetti Tests (SDMT) as a basic tool for a comprehensive soil site characterization to carry out a local seismic response study was analyzed

    Evaluation of the Liquefaction Resistance of Sandy Soil for Shaking Table Tests

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    Seismic liquefaction of loose saturated cohesionless soils is one of the most dangerous and catastrophic phenomena that involves a temporary loss of soil shear strength and stiffness as a consequence of increase pore pressure and reduced effective stress. Therefore, the evaluation of the excess pore pressure induced by shaking is important to predict the liquefaction behaviour of soils at a large scale. In this regard, the study provides the static and dynamic characterisation of a liquefiable sand. For this purpose, a laboratory testing programme, which included the execution of cyclic direct simple shear (CDSS) tests, was performed. The CDSS tests were carried out by means of the CDSS device at the Soil Dynamics and Geotechnical Engineering Laboratory of the University “Kore” of Enna (Italy). The device is designed to allow the soil specimen to be consolidated one-dimensionally and then sheared under constant volume conditions, which replicates the undrained shear condition of the soil specimen. The CDSS tests were conducted to evaluate the liquefaction resistance of the sand under several test conditions, i.e. initial relative density, vertical effective stress or cyclic stress ratios. Results of this study provide useful information for the geotechnical characterisation of the liquefiable sand to be used in shaking table tests at the Laboratory of Earthquake Engineering and Dynamic Analysis (L.E.D.A.) of the University “Kore” of Enna. The laboratory is equipped with a large biaxial laminar shear box for reduced-scale model tests developed to monitor liquefaction under two-dimensional shaking

    Practical structure solution with ARCIMBOLDO

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    ARCIMBOLDO combines the location of small fragments with Phaser and density modification with SHELXE of all possible Phaser solutions. Its uses are explained and illustrated through practical test cases

    Structural remodeling and oligomerization of human cathelicidin on membranes suggest fibril-like structures as active species

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    Antimicrobial peptides as part of the mammalian innate immune system target and remove major bacterial pathogens, often through irreversible damage of their cellular membranes. To explore the mechanism by which the important cathelicidin peptide LL-37 of the human innate immune system interacts with membranes, we performed biochemical, biophysical and structural studies. The crystal structure of LL-37 displays dimers of anti-parallel helices and the formation of amphipathic surfaces. Peptide-detergent interactions introduce remodeling of this structure after occupation of defined hydrophobic sites at the dimer interface. Furthermore, hydrophobic nests are shaped between dimer structures providing another scaffold enclosing detergents. Both scaffolds underline the potential of LL-37 to form defined peptide-lipid complexes in vivo. After adopting the activated peptide conformation LL-37 can polymerize and selectively extract bacterial lipids whereby the membrane is destabilized. The supramolecular fibril-like architectures formed in crystals can be reproduced in a peptide-lipid system after nanogold-labelled LL-37 interacted with lipid vesicles as followed by electron microscopy. We suggest that these supramolecular structures represent the LL-37-membrane active state. Collectively, our study provides new insights into the fascinating plasticity of LL-37 demonstrated at atomic resolution and opens the venue for LL-37-based molecules as novel antibiotics.We would like to thank Sandra Delgado for the technical help in the preparation of the cryoEM vitrified grids and Dr. Isabel Uson and Dr. Ivan De Marino for the Arcimboldo software and valuable help. Funding was provided by the Unidad de Biofisica and the IKERBASQUE and MINECO science foundations

    Assessing the utility of CASP14 models for molecular replacement

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    Funder: CCP4Funder: Max‐Planck‐Gesellschaft; Id: http://dx.doi.org/10.13039/501100004189Abstract: The assessment of CASP models for utility in molecular replacement is a measure of their use in a valuable real‐world application. In CASP7, the metric for molecular replacement assessment involved full likelihood‐based molecular replacement searches; however, this restricted the assessable targets to crystal structures with only one copy of the target in the asymmetric unit, and to those where the search found the correct pose. In CASP10, full molecular replacement searches were replaced by likelihood‐based rigid‐body refinement of models superimposed on the target using the LGA algorithm, with the metric being the refined log‐likelihood‐gain (LLG) score. This enabled multi‐copy targets and very poor models to be evaluated, but a significant further issue remained: the requirement of diffraction data for assessment. We introduce here the relative‐expected‐LLG (reLLG), which is independent of diffraction data. This reLLG is also independent of any crystal form, and can be calculated regardless of the source of the target, be it X‐ray, NMR or cryo‐EM. We calibrate the reLLG against the LLG for targets in CASP14, showing that it is a robust measure of both model and group ranking. Like the LLG, the reLLG shows that accurate coordinate error estimates add substantial value to predicted models. We find that refinement by CASP groups can often convert an inadequate initial model into a successful MR search model. Consistent with findings from others, we show that the AlphaFold2 models are sufficiently good, and reliably so, to surpass other current model generation strategies for attempting molecular replacement phasing

    Clinical patterns of hepatocellular carcinoma in nonalcoholic fatty liver disease: A multicenter prospective study

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    107noNonalcoholic fatty liver disease (NAFLD) represents the hepatic manifestation of metabolic syndrome and may evolve into hepatocellular carcinoma (HCC). Only scanty clinical information is available on HCC in NAFLD. The aim of this multicenter observational prospective study was to assess the clinical features of patients with NAFLD-related HCC (NAFLD-HCC) and to compare them to those of hepatitis C virus (HCV)-related HCC. A total of 756 patients with either NAFLD (145) or HCV-related chronic liver disease (611) were enrolled in secondary care Italian centers. Survival was modeled according to clinical parameters, lead-time bias, and propensity analysis. Compared to HCV, HCC in NAFLD patients had a larger volume, showed more often an infiltrative pattern, and was detected outside specific surveillance. Cirrhosis was present in only about 50% of NAFLD-HCC patients, in contrast to the near totality of HCV-HCC. Regardless of tumor stage, survival was significantly shorter (P = 0.017) in patients with NAFLD-HCC, 25.5 months (95% confidence interval 21.9-29.1), than in those with HCV-HCC, 33.7 months (95% confidence interval 31.9-35.4). To eliminate possible confounders, a propensity score analysis was performed, which showed no more significant difference between the two groups. Additionally, analysis of patients within Milan criteria submitted to curative treatments did not show any difference in survival between NAFLD-HCC and HCV-HCC (respectively, 38.6 versus 41.0 months, P = nonsignificant) Conclusions: NAFLD-HCC is more often detected at a later tumor stage and could arise also in the absence of cirrhosis, but after patient matching, it has a similar survival rate compared to HCV infection; a future challenge will be to identify patients with NAFLD who require more stringent surveillance in order to offer the most timely and effective treatment. (Hepatology 2016;63:827-838)openopenPiscaglia F.; Svegliati-Baroni G.; Barchetti A.; Pecorelli A.; Marinelli S.; Tiribelli C.; Bellentani S.; Bernardi M.; Biselli M.; Caraceni P.; Domenicali M.; Garuti F.; Gramenzi A.; Lenzi B.; Magalotti D.; Cescon M.; Ravaioli M.; Del Poggio P.; Olmi S.; Rapaccini G.L.; Balsamo C.; Di Nolfo M.A.; Vavassori E.; Alberti A.; Benvegnau L.; Gatta A.; Giacomin A.; Vanin V.; Pozzan C.; Maddalo G.; Giampalma E.; Cappelli A.; Golfieri R.; Mosconi C.; Renzulli M.; Roselli P.; Dell'isola S.; Ialungo A.M.; Risso D.; Marenco S.; Sammito G.; Bruzzone L.; Bosco G.; Grieco A.; Pompili M.; Rinninella E.; Siciliano M.; Chiaramonte M.; Guarino M.; Camma C.; Maida M.; Costantino A.; Barcellona M.R.; Schiada L.; Gemini S.; Lanzi A.; Stefanini G.F.; Dall'aglio A.C.; Cappa F.M.; Suzzi A.; Mussetto A.; Treossi O.; Missale G.; Porro E.; Mismas V.; Vivaldi C.; Bolondi L.; Zoli M.; Granito A.; Malagotti D.; Tovoli F.; Trevisani F.; Venerandi L.; Brandi G.; Cucchetti A.; Bugianesi E.; Vanni E.; Mezzabotta L.; Cabibbo G.; Petta S.; Fracanzani A.; Fargion S.; Marra F.; Fani B.; Biasini E.; Sacco R.; Morisco F.; Caporaso N.; Colombo M.; D'ambrosio R.; Croce L.S.; Patti R.; Giannini E.G.; Loria P.; Lonardo A.; Baldelli E.; Miele L.; Farinati F.; Borzio M.; Dionigi E.; Soardo G.; Caturelli E.; Ciccarese F.; Virdone R.; Affronti A.; Foschi F.G.; Borzio F.Piscaglia, F.; Svegliati-Baroni, G.; Barchetti, A.; Pecorelli, A.; Marinelli, S.; Tiribelli, C.; Bellentani, S.; Bernardi, M.; Biselli, M.; Caraceni, P.; Domenicali, M.; Garuti, F.; Gramenzi, A.; Lenzi, B.; Magalotti, D.; Cescon, M.; Ravaioli, M.; Del Poggio, P.; Olmi, S.; Rapaccini, G. L.; Balsamo, C.; Di Nolfo, M. A.; Vavassori, E.; Alberti, A.; Benvegnau, L.; Gatta, A.; Giacomin, A.; Vanin, V.; Pozzan, C.; Maddalo, G.; Giampalma, E.; Cappelli, A.; Golfieri, R.; Mosconi, C.; Renzulli, M.; Roselli, P.; Dell'Isola, S.; Ialungo, A. M.; Risso, D.; Marenco, S.; Sammito, G.; Bruzzone, L.; Bosco, G.; Grieco, A.; Pompili, M.; Rinninella, E.; Siciliano, M.; Chiaramonte, M.; Guarino, M.; Camma, C.; Maida, M.; Costantino, A.; Barcellona, M. R.; Schiada, L.; Gemini, S.; Lanzi, A.; Stefanini, G. F.; Dall'Aglio, A. C.; Cappa, F. M.; Suzzi, A.; Mussetto, A.; Treossi, O.; Missale, G.; Porro, E.; Mismas, V.; Vivaldi, C.; Bolondi, L.; Zoli, M.; Granito, A.; Malagotti, D.; Tovoli, F.; Trevisani, F.; Venerandi, L.; Brandi, G.; Cucchetti, A.; Bugianesi, E.; Vanni, E.; Mezzabotta, L.; Cabibbo, G.; Petta, S.; Fracanzani, A.; Fargion, S.; Marra, F.; Fani, B.; Biasini, E.; Sacco, R.; Morisco, F.; Caporaso, N.; Colombo, M.; D'Ambrosio, R.; Croce, L. S.; Patti, R.; Giannini, E. G.; Loria, P.; Lonardo, A.; Baldelli, E.; Miele, L.; Farinati, F.; Borzio, M.; Dionigi, E.; Soardo, G.; Caturelli, E.; Ciccarese, F.; Virdone, R.; Affronti, A.; Foschi, F. G.; Borzio, F

    The CCP4 suite: integrative software for macromolecular crystallography

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    The Collaborative Computational Project No. 4 (CCP4) is a UK-led international collective with a mission to develop, test, distribute and promote software for macromolecular crystallography. The CCP4 suite is a multiplatform collection of programs brought together by familiar execution routines, a set of common libraries and graphical interfaces. The CCP4 suite has experienced several considerable changes since its last reference article, involving new infrastructure, original programs and graphical interfaces. This article, which is intended as a general literature citation for the use of the CCP4 software suite in structure determination, will guide the reader through such transformations, offering a general overview of the new features and outlining future developments. As such, it aims to highlight the individual programs that comprise the suite and to provide the latest references to them for perusal by crystallographers around the world
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