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Sample records for core protein p24

  1. Production and purification of immunologically active core protein p24 from HIV-1 fused to ricin toxin B subunit in E. coli

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    Gómez-Lim Miguel A

    2009-02-01

    Full Text Available Abstract Background Gag protein from HIV-1 is a polyprotein of 55 kDa, which, during viral maturation, is cleaved to release matrix p17, core p24 and nucleocapsid proteins. The p24 antigen contains epitopes that prime helper CD4 T-cells, which have been demonstrated to be protective and it can elicit lymphocyte proliferation. Thus, p24 is likely to be an integral part of any multicomponent HIV vaccine. The availability of an optimal adjuvant and carrier to enhance antiviral responses may accelerate the development of a vaccine candidate against HIV. The aim of this study was to investigate the adjuvant-carrier properties of the B ricin subunit (RTB when fused to p24. Results A fusion between ricin toxin B subunit and p24 HIV (RTB/p24 was expressed in E. coli. Affinity chromatography was used for purification of p24 alone and RTB/p24 from cytosolic fractions. Biological activity of RTB/p24 was determined by ELISA and affinity chromatography using the artificial receptor glycoprotein asialofetuin. Both assays have demonstrated that RTB/p24 is able to interact with complex sugars, suggesting that the chimeric protein retains lectin activity. Also, RTB/p24 was demonstrated to be immunologically active in mice. Two weeks after intraperitoneal inoculation with RTB/p24 without an adjuvant, a strong anti-p24 immune response was detected. The levels of the antibodies were comparable to those found in mice immunized with p24 alone in the presence of Freund adjuvant. RTB/p24 inoculated intranasally in mice, also elicited significant immune responses to p24, although the response was not as strong as that obtained in mice immunized with p24 in the presence of the mucosal adjuvant cholera toxin. Conclusion In this work, we report the expression in E. coli of HIV-1 p24 fused to the subunit B of ricin toxin. The high levels of antibodies obtained after intranasal and intraperitoneal immunization of mice demonstrate the adjuvant-carrier properties of RTB when

  2. Radioimmunoassay and enzyme-linked immunoassay of antibodies directed against lymphadenopathy-associated virus (LAV) proteins larger than the core protein (P24)

    International Nuclear Information System (INIS)

    Neurath, A.R.; Strick, N.; Lee, Y.S.; Nilsen, T.; Baker, L.; Sproul, P.; Rubinstein, P.; Taylor, P.; Stevens, C.E.; Gold, J.W.M.

    1985-01-01

    Molecular exclusion chromatography of crude LAV antigen preparations allows separation of most of P24 from larger proteins of LAV (PL). PL and 125 I- or beta-lactamase-labeled anti-LAV were used as reagents for radioimmunoassay (RIA) - or enzyme-linked immunoassay (ELISA) - inhibition tests to detect antibodies directed predominantly against PL (anti-PL). Among 257 individuals belonging to groups at high risk of developing AIDS, 117 (45.5%) were positive for anti-PL and 108 (42%) for anti-P24, respectively. The 2 individuals among 600 random blood donors found to be anti-P24-positive in the preceding study also had anti-PL in their serum. Sera from 500 additional blood donors were screened for anti-PL and 1 of these was positive. The implication of these findings for screening of blood donors is discussed. (Auth.)

  3. Radioimmunoassay and enzyme-linked immunoassay of antibodies directed against lymphadenopathy-associated virus (LAV) proteins larger than the core protein (P24)

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    Neurath, A R; Strick, N; Lee, Y S; Nilsen, T; Baker, L; Sproul, P; Rubinstein, P; Taylor, P; Stevens, C E; Gold, J W.M.

    1985-10-01

    Molecular exclusion chromatography of crude LAV antigen preparations allows separation of most of P24 from larger proteins of LAV (PL). PL and /sup 125/I- or beta-lactamase-labeled anti-LAV were used as reagents for radioimmunoassay (RIA) - or enzyme-linked immunoassay (ELISA) - inhibition tests to detect antibodies directed predominantly against PL (anti-PL). Among 257 individuals belonging to groups at high risk of developing AIDS, 117 (45.5%) were positive for anti-PL and 108 (42%) for anti-P24, respectively. The 2 individuals among 600 random blood donors found to be anti-P24-positive in the preceding study also had anti-PL in their serum. Sera from 500 additional blood donors were screened for anti-PL and 1 of these was positive. The implication of these findings for screening of blood donors is discussed. 17 refs.; 2 figs.; 1 table.

  4. Disparate effects of p24alpha and p24delta on secretory protein transport and processing.

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    Jeroen R P M Strating

    Full Text Available BACKGROUND: The p24 family is thought to be somehow involved in endoplasmic reticulum (ER-to-Golgi protein transport. A subset of the p24 proteins (p24alpha(3, -beta(1, -gamma(3 and -delta(2 is upregulated when Xenopus laevis intermediate pituitary melanotrope cells are physiologically activated to produce vast amounts of their major secretory cargo, the prohormone proopiomelanocortin (POMC. METHODOLOGY/PRINCIPAL FINDINGS: Here we find that transgene expression of p24alpha(3 or p24delta(2 specifically in the Xenopus melanotrope cells in both cases causes an effective displacement of the endogenous p24 proteins, resulting in severely distorted p24 systems and disparate melanotrope cell phenotypes. Transgene expression of p24alpha(3 greatly reduces POMC transport and leads to accumulation of the prohormone in large, ER-localized electron-dense structures, whereas p24delta(2-transgenesis does not influence the overall ultrastructure of the cells nor POMC transport and cleavage, but affects the Golgi-based processes of POMC glycomaturation and sulfation. CONCLUSIONS/SIGNIFICANCE: Transgenic expression of two distinct p24 family members has disparate effects on secretory pathway functioning, illustrating the specificity and non-redundancy of our transgenic approach. We conclude that members of the p24 family furnish subcompartments of the secretory pathway with specific sets of machinery cargo to provide the proper microenvironments for efficient and correct secretory protein transport and processing.

  5. Radioimmunoassay and enzyme-linked immunoassay of antibodies to the core protein (P24) of human T-lymphotropic virus (HTLV III). [Acquired immunodeficiency syndrome (AIDS)

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    Neurath, A R; Strick, N; Sproul, P

    1985-05-01

    Human T-cell lymphotropic viruses designated HTLV III or LAV are considered to represent the causative agents of the acquired immunodeficiency syndrome (AIDS). Therefore a simple direct RIA or ELISA method for antibodies to distinct epitopes of HTLV III/LAV structural components would be of great value. The authors describe RIA and ELISA assays which obviate the need for purified virus or virus proteins, do not utilize infected cells and thus do not diminish the source for continuous production of viral antigens and are specific for a major core protein of HTLV III/LAV.

  6. Biophysical characterization of the feline immunodeficiency virus p24 capsid protein conformation and in vitro capsid assembly.

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    Jennifer Serrière

    Full Text Available The Feline Immunodeficiency Virus (FIV capsid protein p24 oligomerizes to form a closed capsid that protects the viral genome. Because of its crucial role in the virion, FIV p24 is an interesting target for the development of therapeutic strategies, although little is known about its structure and assembly. We defined and optimized a protocol to overexpress recombinant FIV capsid protein in a bacterial system. Circular dichroism and isothermal titration calorimetry experiments showed that the structure of the purified FIV p24 protein was comprised mainly of α-helices. Dynamic light scattering (DLS and cross-linking experiments demonstrated that p24 was monomeric at low concentration and dimeric at high concentration. We developed a protocol for the in vitro assembly of the FIV capsid. As with HIV, an increased ionic strength resulted in FIV p24 assembly in vitro. Assembly appeared to be dependent on temperature, salt concentration, and protein concentration. The FIV p24 assembly kinetics was monitored by DLS. A limit end-point diameter suggested assembly into objects of definite shapes. This was confirmed by electron microscopy, where FIV p24 assembled into spherical particles. Comparison of FIV p24 with other retroviral capsid proteins showed that FIV assembly is particular and requires further specific study.

  7. A Cell Internalizing Antibody Targeting Capsid Protein (p24 Inhibits the Replication of HIV-1 in T Cells Lines and PBMCs: A Proof of Concept Study.

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    Syed A Ali

    Full Text Available There remains a need for newer therapeutic approaches to combat HIV/AIDS. Viral capsid protein p24 plays important roles in HIV pathogenesis. Peptides and small molecule inhibitors targeting p24 have shown to inhibit virus replication in treated cell. High specificity and biological stability of monoclonal antibodies (mAbs make them an attractive contender for in vivo treatments. However, mAbs do not enter into cells, thus are restricted to target surface molecules. This also makes targeting intracellular HIV-1 p24 a challenge. A mAb specific to p24 that can internalize into the HIV-infected cells is hypothesized to inhibit the virus replication. We selected a mAb that has previously shown to inhibit p24 polymerization in an in vitro assay and chemically conjugated it with cell penetrating peptides (CPP to generate cell internalizing anti-p24 mAbs. Out of 8 CPPs tested, κFGF-MTS -conjugated mAbs internalized T cells most efficiently. At nontoxic concentration, the κFGF-MTS-anti-p24-mAbs reduced the HIV-1 replication up to 73 and 49% in T-lymphocyte and PBMCs respectively. Marked inhibition of HIV-1 replication in relevant cells by κFGF-MTS-anti-p24-mAbs represents a viable strategy to target HIV proteins present inside the cells.

  8. 3D Structure and Interaction of p24β and p24δ Golgi Dynamics Domains: Implication for p24 Complex Formation and Cargo Transport.

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    Nagae, Masamichi; Hirata, Tetsuya; Morita-Matsumoto, Kana; Theiler, Romina; Fujita, Morihisa; Kinoshita, Taroh; Yamaguchi, Yoshiki

    2016-10-09

    The p24 family consists of four subfamilies (p24α, p24β, p24γ, and p24δ), and the proteins are thought to form hetero-oligomeric complexes for efficient transport of cargo proteins from the endoplasmic reticulum to the Golgi apparatus. The proteins possess a conserved luminal Golgi dynamics (GOLD) domain, whose functions are largely unknown. Here, we present structural and biochemical studies of p24β1 and p24δ1 GOLD domains. Use of GOLD domain-deleted mutants revealed that the GOLD domain of p24δ1 is required for proper p24 hetero-oligomeric complex formation and efficient transport of GPI-anchored proteins. The p24β1 and p24δ1 GOLD domains share a common β-sandwich fold with a characteristic intrasheet disulfide bond. The GOLD domain of p24δ1 crystallized as dimers, allowing the analysis of a homophilic interaction site. Surface plasmon resonance and solution NMR analyses revealed that p24β1 and p24δ1 GOLD domains interact weakly (K d = ~10 -4 M). Bi-protein titration provided interaction site maps. We propose that the heterophilic interaction of p24 GOLD domains contributes to the formation of the p24 hetero-oligomeric complex and to efficient cargo transport. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Random close packing in protein cores.

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    Gaines, Jennifer C; Smith, W Wendell; Regan, Lynne; O'Hern, Corey S

    2016-03-01

    Shortly after the determination of the first protein x-ray crystal structures, researchers analyzed their cores and reported packing fractions ϕ ≈ 0.75, a value that is similar to close packing of equal-sized spheres. A limitation of these analyses was the use of extended atom models, rather than the more physically accurate explicit hydrogen model. The validity of the explicit hydrogen model was proved in our previous studies by its ability to predict the side chain dihedral angle distributions observed in proteins. In contrast, the extended atom model is not able to recapitulate the side chain dihedral angle distributions, and gives rise to large atomic clashes at side chain dihedral angle combinations that are highly probable in protein crystal structures. Here, we employ the explicit hydrogen model to calculate the packing fraction of the cores of over 200 high-resolution protein structures. We find that these protein cores have ϕ ≈ 0.56, which is similar to results obtained from simulations of random packings of individual amino acids. This result provides a deeper understanding of the physical basis of protein structure that will enable predictions of the effects of amino acid mutations to protein cores and interfaces of known structure.

  10. Core-shell microparticles for protein sequestration and controlled release of a protein-laden core.

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    Rinker, Torri E; Philbrick, Brandon D; Temenoff, Johnna S

    2017-07-01

    Development of multifunctional biomaterials that sequester, isolate, and redeliver cell-secreted proteins at a specific timepoint may be required to achieve the level of temporal control needed to more fully regulate tissue regeneration and repair. In response, we fabricated core-shell heparin-poly(ethylene-glycol) (PEG) microparticles (MPs) with a degradable PEG-based shell that can temporally control delivery of protein-laden heparin MPs. Core-shell MPs were fabricated via a re-emulsification technique and the number of heparin MPs per PEG-based shell could be tuned by varying the mass of heparin MPs in the precursor PEG phase. When heparin MPs were loaded with bone morphogenetic protein-2 (BMP-2) and then encapsulated into core-shell MPs, degradable core-shell MPs initiated similar C2C12 cell alkaline phosphatase (ALP) activity as the soluble control, while non-degradable core-shell MPs initiated a significantly lower response (85+19% vs. 9.0+4.8% of the soluble control, respectively). Similarly, when degradable core-shell MPs were formed and then loaded with BMP-2, they induced a ∼7-fold higher C2C12 ALP activity than the soluble control. As C2C12 ALP activity was enhanced by BMP-2, these studies indicated that degradable core-shell MPs were able to deliver a bioactive, BMP-2-laden heparin MP core. Overall, these dynamic core-shell MPs have the potential to sequester, isolate, and then redeliver proteins attached to a heparin core to initiate a cell response, which could be of great benefit to tissue regeneration applications requiring tight temporal control over protein presentation. Tissue repair requires temporally controlled presentation of potent proteins. Recently, biomaterial-mediated binding (sequestration) of cell-secreted proteins has emerged as a strategy to harness the regenerative potential of naturally produced proteins, but this strategy currently only allows immediate amplification and re-delivery of these signals. The multifunctional, dynamic

  11. Differential Stoichiometry among Core Ribosomal Proteins

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    Nikolai Slavov

    2015-11-01

    Full Text Available Understanding the regulation and structure of ribosomes is essential to understanding protein synthesis and its dysregulation in disease. While ribosomes are believed to have a fixed stoichiometry among their core ribosomal proteins (RPs, some experiments suggest a more variable composition. Testing such variability requires direct and precise quantification of RPs. We used mass spectrometry to directly quantify RPs across monosomes and polysomes of mouse embryonic stem cells (ESC and budding yeast. Our data show that the stoichiometry among core RPs in wild-type yeast cells and ESC depends both on the growth conditions and on the number of ribosomes bound per mRNA. Furthermore, we find that the fitness of cells with a deleted RP-gene is inversely proportional to the enrichment of the corresponding RP in polysomes. Together, our findings support the existence of ribosomes with distinct protein composition and physiological function.

  12. Random close packing in protein cores

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    Gaines, Jennifer C.; Smith, W. Wendell; Regan, Lynne; O'Hern, Corey S.

    2015-01-01

    Shortly after the determination of the first protein x-ray crystal structures, researchers analyzed their cores and reported packing fractions $\\phi \\approx 0.75$, a value that is similar to close packing equal-sized spheres. A limitation of these analyses was the use of `extended atom' models, rather than the more physically accurate `explicit hydrogen' model. The validity of using the explicit hydrogen model is proved by its ability to predict the side chain dihedral angle distributions obs...

  13. HIV p24 as scaffold for presenting conformational HIV Env antigens.

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    Maria Tagliamonte

    Full Text Available Heterologous protein scaffolds engrafted with structurally defined HIV Env epitopes recognized by broadly neutralizing monoclonal antibodies (MAbs represent a promising strategy to elicit broad neutralizing antibodies. In such regards, a protein scaffold based on the HIV p24 CA protein is a highly attractive approach, providing also Gag epitopes for eliciting HIV non-neutralizing protective antibodies and specific CD4(+ and CD8(+ T cell responses. In the present study, computational techniques were employed to verify the presence of acceptor sites for conformational HIV Env epitopes and, as proof of concept, the analysis of HIV p24 CA-based scaffolds using a complete V3 loop in a MAb-bound conformation is presented. The V3-p24 epitope-scaffold proteins show the formation of capsomers made of hexamers similarly to the p24 wild type protein. Moreover, the conformational V3 loop presented on p24 scaffold is recognized by a panel of anti-V3 MAbs. The results suggest that HIV p24 CA protein has suitable acceptor sites for engrafting foreign epitopes, without disrupting the formation of capsomer hexamer structures, and that the V3 epitope does retain its antibody-bound conformation. This strongly support the feasibility of developing a scaffolding strategy based on p24 CA proteins displaying conformational minimal structural, antigenic HIV Env epitopes.

  14. Hepatitis C Virus Core Protein Decreases Lipid Droplet Turnover

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    Harris, Charles; Herker, Eva; Farese, Robert V.; Ott, Melanie

    2011-01-01

    Steatosis is a frequent complication of hepatitis C virus infection. In mice, this condition is recapitulated by the expression of a single viral protein, the nucleocapsid core. Core localizes to the surface of lipid droplets (LDs) in infected liver cells through a process dependent on host diacylglycerol acyltransferase 1 (DGAT1), an enzyme that synthesizes triglycerides in the endoplasmic reticulum. Whether DGAT1 also plays a role in core-induced steatosis is uncertain. Here, we show that mouse embryonic fibroblasts isolated from DGAT1−/− mice are protected from core-induced steatosis, as are livers of DGAT1−/− mice expressing core, demonstrating that the steatosis is DGAT1-dependent. Surprisingly, core expression did not increase DGAT1 activity or triglyceride synthesis, thus excluding the possibility that core activates DGAT1 to cause steatosis. Instead, we find that DGAT1-dependent localization of core to LDs is a prerequisite for the steatogenic properties of the core. Using biochemical and immunofluorescence microscopy techniques, we show that the turnover of lipids in core-coated droplets is decreased, providing a physiological mechanism for core-induced steatosis. Our results support a bipartite model in which core first requires DGAT1 to gain access to LDs, and then LD-localized core interferes with triglyceride turnover, thus stabilizing lipid droplets and leading to steatosis. PMID:21984835

  15. Structural characterization of Mumps virus fusion protein core

    International Nuclear Information System (INIS)

    Liu Yueyong; Xu Yanhui; Lou Zhiyong; Zhu Jieqing; Hu Xuebo; Gao, George F.; Qiu Bingsheng; Rao Zihe; Tien, Po

    2006-01-01

    The fusion proteins of enveloped viruses mediating the fusion between the viral and cellular membranes comprise two discontinuous heptad repeat (HR) domains located at the ectodomain of the enveloped glycoproteins. The crystal structure of the fusion protein core of Mumps virus (MuV) was determined at 2.2 A resolution. The complex is a six-helix bundle in which three HR1 peptides form a central highly hydrophobic coiled-coil and three HR2 peptides pack against the hydrophobic grooves on the surface of central coiled-coil in an oblique antiparallel manner. Fusion core of MuV, like those of simian virus 5 and human respiratory syncytium virus, forms typical 3-4-4-4-3 spacing. The similar charecterization in HR1 regions, as well as the existence of O-X-O motif in extended regions of HR2 helix, suggests a basic rule for the formation of the fusion core of viral fusion proteins

  16. Modulation of mitogen-activated protein kinase-activated protein kinase 3 by hepatitis C virus core protein

    DEFF Research Database (Denmark)

    Ngo, HT; Pham, Long; Kim, JW

    2013-01-01

    Hepatitis C virus (HCV) is highly dependent on cellular proteins for its own propagation. In order to identify the cellular factors involved in HCV propagation, we performed protein microarray assays using the HCV core protein as a probe. Of ~9,000 host proteins immobilized in a microarray...... inducers. Binding of HCV core to MAPKAPK3 was confirmed by in vitro pulldown assay and further verified by coimmunoprecipitation assay. HCV core protein interacted with MAPKAPK3 through amino acid residues 41 to 75 of core and the N-terminal half of kinase domain of MAPKAPK3. In addition, both RNA...... increased HCV IRES-mediated translation and MAPKAPK3-dependent HCV IRES activity was further increased by core protein. These data suggest that HCV core may modulate MAPKAPK3 to facilitate its own propagation....

  17. Prediction of Hydrophobic Cores of Proteins Using Wavelet Analysis.

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    Hirakawa; Kuhara

    1997-01-01

    Information concerning the secondary structures, flexibility, epitope and hydrophobic regions of amino acid sequences can be extracted by assigning physicochemical indices to each amino acid residue, and information on structure can be derived using the sliding window averaging technique, which is in wide use for smoothing out raw functions. Wavelet analysis has shown great potential and applicability in many fields, such as astronomy, radar, earthquake prediction, and signal or image processing. This approach is efficient for removing noise from various functions. Here we employed wavelet analysis to smooth out a plot assigned to a hydrophobicity index for amino acid sequences. We then used the resulting function to predict hydrophobic cores in globular proteins. We calculated the prediction accuracy for the hydrophobic cores of 88 representative set of proteins. Use of wavelet analysis made feasible the prediction of hydrophobic cores at 6.13% greater accuracy than the sliding window averaging technique.

  18. Colorful packages : fluorescent proteins in complex coacervate core micelles

    NARCIS (Netherlands)

    Nolles, Antsje

    2018-01-01

    This thesis explores the encapsulation of fluorescent proteins (FPs) into complex coacervate core micelles (C3Ms) and features the impact of this encapsulation on the biophysical properties of the FPs. In total eight different FPs were investigated originating from two different classes

  19. Bone induction by biomimetic PLGA copolymer loaded with a novel synthetic RADA16-P24 peptide in vivo

    International Nuclear Information System (INIS)

    Pan, Haitao; Hao, Shaofei; Zheng, Qixin; Li, Jingfeng; Zheng, Jin; Hu, Zhilei; Yang, Shuhua; Guo, Xiaodong; Yang, Qin

    2013-01-01

    Bone morphogenetic protein-2 (BMP-2) is a key bone morphogenetic protein, and poly(lactic-co-glycolic acid) (PLGA) has been widely used as scaffold for clinical use to carry treatment protein. In the previous studies, we have synthesized BMP-2-related peptide (P24) and found its capacity of inducing bone regeneration. In this research, we have synthesized a new amphiphilic peptide Ac-RADA RADA RADA RADA S[PO4]KIPKASSVPTELSAISTLYLDDD-CONH2 (RADA16-P24) with an assembly peptide RADA16-Ion the P24 item of BMP2 to form divalent ion-induced gelatin. Two methods of physisorption and chemical cross-linking were used to bind RADA16-P24 onto the surface of the copolymer PLGA to synthesize RADA16-P24–PLGA, and its capacity of attaching bone marrow stromal cells (BMSCs) was evaluated in vitro and inducing ectopic bone formation was examined in vivo. In vitro our results demonstrated that RADA16-P24–PLGA copolymer prepared by physisorbing or prepared by chemical cross-linking had a peptide binding rate of (2.0180 ± 0.5296)% or (10.0820 ± 0.8405)% respectively (P < 0.05). In addition the BMSCs proliferated vigorously in the RADA16-P24–PLGA biomaterials. Significantly the percentage of BMSCs attached to RADA16-P24–PLGA composite prepared by chemical cross-linking and physisorbing were (71.4 ± 7.5) % or (46.7 ± 5.8) % (P < 0.05). The in vivo study showed that RADA16-P24–PLGA chemical cross-linking could better induce ectopic bone formation compared with RADA16-P24–PLGA physisorbing and PLGA. It is concluded that the PLGA copolymer is a good RADA16-P24 carrier. This novel RADA16-P24–PLGA composite has strong osteogenic capability. - Highlights: • We have synthesized a new RADA16-P24 amphiphilic peptide. • It is an assembly peptide RADA16-Ion the P24 to form divalent ion-induced gelatin. • RADA16-P24/PLGA could better induce etopia osteogenesis compared with PLGA. • RADA16-P24–PLGA has strong osteogenic capability

  20. Bone induction by biomimetic PLGA copolymer loaded with a novel synthetic RADA16-P24 peptide in vivo

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    Pan, Haitao; Hao, Shaofei [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Zheng, Qixin, E-mail: zheng-qx@163.com [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Li, Jingfeng [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Department of Orthopedics, Zhongnan Hospital of Wuhan University, Wuhan 430071 (China); Zheng, Jin; Hu, Zhilei; Yang, Shuhua; Guo, Xiaodong [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Yang, Qin [Advanced Biomaterials and Tissue Engineering Center, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2013-08-01

    Bone morphogenetic protein-2 (BMP-2) is a key bone morphogenetic protein, and poly(lactic-co-glycolic acid) (PLGA) has been widely used as scaffold for clinical use to carry treatment protein. In the previous studies, we have synthesized BMP-2-related peptide (P24) and found its capacity of inducing bone regeneration. In this research, we have synthesized a new amphiphilic peptide Ac-RADA RADA RADA RADA S[PO4]KIPKASSVPTELSAISTLYLDDD-CONH2 (RADA16-P24) with an assembly peptide RADA16-Ion the P24 item of BMP2 to form divalent ion-induced gelatin. Two methods of physisorption and chemical cross-linking were used to bind RADA16-P24 onto the surface of the copolymer PLGA to synthesize RADA16-P24–PLGA, and its capacity of attaching bone marrow stromal cells (BMSCs) was evaluated in vitro and inducing ectopic bone formation was examined in vivo. In vitro our results demonstrated that RADA16-P24–PLGA copolymer prepared by physisorbing or prepared by chemical cross-linking had a peptide binding rate of (2.0180 ± 0.5296)% or (10.0820 ± 0.8405)% respectively (P < 0.05). In addition the BMSCs proliferated vigorously in the RADA16-P24–PLGA biomaterials. Significantly the percentage of BMSCs attached to RADA16-P24–PLGA composite prepared by chemical cross-linking and physisorbing were (71.4 ± 7.5) % or (46.7 ± 5.8) % (P < 0.05). The in vivo study showed that RADA16-P24–PLGA chemical cross-linking could better induce ectopic bone formation compared with RADA16-P24–PLGA physisorbing and PLGA. It is concluded that the PLGA copolymer is a good RADA16-P24 carrier. This novel RADA16-P24–PLGA composite has strong osteogenic capability. - Highlights: • We have synthesized a new RADA16-P24 amphiphilic peptide. • It is an assembly peptide RADA16-Ion the P24 to form divalent ion-induced gelatin. • RADA16-P24/PLGA could better induce etopia osteogenesis compared with PLGA. • RADA16-P24–PLGA has strong osteogenic capability.

  1. Towards biocompatible vaccine delivery systems: interactions of colloidal PECs based on polysaccharides with HIV-1 p24 antigen.

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    Drogoz, Alexandre; Munier, Séverine; Verrier, Bernard; David, Laurent; Domard, Alain; Delair, Thierry

    2008-02-01

    This work reports on the interactions of a model protein (p24, the capside protein of HIV-1 virus) with colloids obtained from polyelectrolyte complexes (PECs) involving two polysaccharides: chitosan and dextran sulfate (DS). The PECs were elaborated by a one-shot addition of default amounts of one counterpart to the polymer in excess. Depending on the nature of the excess polyelectrolyte, the submicrometric colloid was either positively or negatively charged. HIV-1 capsid p24 protein was chosen as antigen, the ultrapure form, lipopolysaccharide-free (endotoxin-, vaccine grade) was used in most experiments, as the level of purity of the protein had a great impact on the immobilization process. p24 sorption kinetics, isotherms, and loading capacities were investigated for positively and negatively charged particles of chitosans and dextran sulfates differing in degrees of polymerization (DP) or acetylation (DA). Compared with the positive particles, negatively charged colloids had higher binding capacities, faster kinetics, and a better stability of the adsorbed p24. Capacities up to 600 mg x g(-1) (protein-colloid) were obtained, suggesting that the protein interacted within the shell of the particles. Small-angle X-rays scattering experiments confirmed this hypothesis. Finally, the immunogenicity of the p24-covered particles was assessed for vaccine purposes in mice. The antibody titers obtained with immobilized p24 was dose dependent and in the same range as for Freund's adjuvant, a gold standard for humoral responses.

  2. The cargo receptor p24A facilitates calcium sensing receptor maturation and stabilization in the early secretory pathway

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    Stepanchick, Ann; Breitwieser, Gerda E.

    2010-01-01

    The calcium sensing receptor (CaSR) is a Family 3/C G protein-coupled receptor with slow and partial targeting to the plasma membrane in both native and heterologous cells. We identified cargo receptor family member p24A in yeast two-hybrid screens with the CaSR carboxyl terminus. Interactions were confirmed by immunoprecipitation of either p24A or CaSR in transiently transfected HEK293 cells. Only the immaturely glycosylated form of CaSR interacts with p24A. Dissociation likely occurs in the endoplasmic reticulum Golgi intermediate compartment (ERGIC) or cis-Golgi, since only the uncleaved form of a CaSR mutant sensitive to the trans-Golgi enzyme furin was coimmunoprecipitated with p24A. p24A and p24A(ΔGOLD) significantly increased total and plasma membrane CaSR protein but p24A(FF/AA) did not. The CaSR carboxyl terminus distal to T868 is required for differential sensitivity to p24A and its mutants. Interaction with p24A therefore increases CaSR stability in the ER and enhances plasma membrane targeting. Neither wt Sar1p or the T39N mutant increased CaSR maturation or abundance while the H79G mutant increased abundance but prevented maturation of CaSR. These results suggest that p24A is the limiting factor in CaSR trafficking in the early secretory pathway, and that cycling between the ER and ERGIC protects CaSR from degradation. PMID:20361938

  3. Homogeneous protein analysis by magnetic core-shell nanorod probes

    KAUST Repository

    Schrittwieser, Stefan

    2016-03-29

    Studying protein interactions is of vital importance both to fundamental biology research and to medical applications. Here, we report on the experimental proof of a universally applicable label-free homogeneous platform for rapid protein analysis. It is based on optically detecting changes in the rotational dynamics of magnetically agitated core-shell nanorods upon their specific interaction with proteins. By adjusting the excitation frequency, we are able to optimize the measurement signal for each analyte protein size. In addition, due to the locking of the optical signal to the magnetic excitation frequency, background signals are suppressed, thus allowing exclusive studies of processes at the nanoprobe surface only. We study target proteins (soluble domain of the human epidermal growth factor receptor 2 - sHER2) specifically binding to antibodies (trastuzumab) immobilized on the surface of our nanoprobes and demonstrate direct deduction of their respective sizes. Additionally, we examine the dependence of our measurement signal on the concentration of the analyte protein, and deduce a minimally detectable sHER2 concentration of 440 pM. For our homogeneous measurement platform, good dispersion stability of the applied nanoprobes under physiological conditions is of vital importance. To that end, we support our measurement data by theoretical modeling of the total particle-particle interaction energies. The successful implementation of our platform offers scope for applications in biomarker-based diagnostics as well as for answering basic biology questions.

  4. A Sandwich HIV p24 Amperometric Immunosensor Based on a Direct Gold Electroplating-Modified Electrode

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    Ning Gan

    2012-05-01

    Full Text Available Acquired immune deficiency syndrome (AIDS is a severe communicable immune deficiency disease caused by the human immune deficiency virus (HIV. The analysis laboratory diagnosis of HIV infection is a crucial aspect of controlling AIDS. The p24 antigen, the HIV-1 capsid protein, is of considerable diagnostic interest because it is detectable several days earlier than host-generated HIV antibodies following HIV exposure. We present herein a new sandwich HIV p24 immunosensor based on directly electroplating an electrode surface with gold nanoparticles using chronoamperometry, which greatly increased the conductivity and reversibility of the electrode. Under optimum conditions, the electrochemical signal showed a linear relationship with the concentration of p24, ranging from 0.01 ng/mL to 100 ng/mL (R > 0.99, and the detection limit was 0.008 ng/mL. Compared with ELISA, this method increased the sensitivity by more than two orders of magnitude (the sensitivity of ELISA for p24 is about 1 ng/mL. This immunosensor may be broadly applied to clinical samples, being distinguished by its ease of use, mild reaction conditions, guaranteed reproducibility, and good anti-interference ability.

  5. A sandwich HIV p24 amperometric immunosensor based on a direct gold electroplating-modified electrode.

    Science.gov (United States)

    Zheng, Lei; Jia, Liyong; Li, Bo; Situ, Bo; Liu, Qinlan; Wang, Qian; Gan, Ning

    2012-05-18

    Acquired immune deficiency syndrome (AIDS) is a severe communicable immune deficiency disease caused by the human immune deficiency virus (HIV). The analysis laboratory diagnosis of HIV infection is a crucial aspect of controlling AIDS. The p24 antigen, the HIV-1 capsid protein, is of considerable diagnostic interest because it is detectable several days earlier than host-generated HIV antibodies following HIV exposure. We present herein a new sandwich HIV p24 immunosensor based on directly electroplating an electrode surface with gold nanoparticles using chronoamperometry, which greatly increased the conductivity and reversibility of the electrode. Under optimum conditions, the electrochemical signal showed a linear relationship with the concentration of p24, ranging from 0.01 ng/mL to 100 ng/mL (R > 0.99), and the detection limit was 0.008 ng/mL. Compared with ELISA, this method increased the sensitivity by more than two orders of magnitude (the sensitivity of ELISA for p24 is about 1 ng/mL). This immunosensor may be broadly applied to clinical samples, being distinguished by its ease of use, mild reaction conditions, guaranteed reproducibility, and good anti-interference ability.

  6. Hepatitis B core protein as a therapeutic target.

    Science.gov (United States)

    Mak, Lung-Yi; Wong, Danny Ka-Ho; Seto, Wai-Kay; Lai, Ching-Lung; Yuen, Man Fung

    2017-12-01

    Chronic hepatitis B virus (HBV) infection is difficult to cure, due to the presence of covalently-closed-circular DNA and virus-mediated blunting of host immune response. Existing therapies with nucleos(t)ide analogue or pegylated-interferon are not sufficient to achieve a high rate of HBV surface antigen seroclearance, a more desirable treatment outcome. Novel therapeutic agents targeting alternative viral replication steps are being developed. In this review, we will discuss the hepatitis B core antigen (HBcAg) as a therapeutic target. Areas covered: The basic structure and fundamental functions of HBcAg including nucleocapsid assembly, pre-genomic RNA encapsidation, reverse transcription, virion formation, cccDNA amplification, immune response regulation, and HBx protein interaction will be reviewed. Most of these are identified as therapeutic targets and tested in in vitro and in vivo studies, although clinical trials are scanty. Among the different components, the core protein allosteric modulators (CpAM) have been most widely investigated and appear promising in clinical trials. Expert opinion: The multiple and essential functions of HBcAg for HBV life cycle are important and attractive targets for HBV therapeutic interventions. Controlled trials involving CpAM are awaited. Apart from CpAM, drugs directed against different functions of HBcAg may be further explored to maximize the chance of cure.

  7. A monoclonal antibody (SJ-9A4) to P24 present on common alls, neuroblastomas and platelets - II. Characterization of P24 and shedding in vitro and in vivo.

    Science.gov (United States)

    Komada, Y; Peiper, S C; Melvin, S L; Tarnowski, B; Green, A A

    1983-01-01

    The release of soluble P24 antigen into culture medium by common acute lymphoblastic leukemia (C-ALL) and neuroblastoma (NB) cell lines was studied. P24 release by C-ALL cells was detected using a solid phase indirect radioimmunometric assay (IRA) which combines the specificity of lectins and monoclonal antibodies (MoAb) and using immunoadsorption of labeled P24 in spent medium from cells incubated with 35S-methionine (met). No P24 was present in the medium of cells pulse labeled at 37 degrees C when they were placed at 4 degrees C, thus this is an active process. P24 release by NB cells could not be detected by IRA, but could be detected by immunoadsorption of spent medium of metabolically-labeled cells. The absence of IRA activity of P24 from NB spent medium was due to decreased glycosylation and thus no binding to the lectins employed in the IRA was observed. This was confirmed by lectin affinity chromatography which showed that P24 in the spent medium from C-ALL cells bound Ricinus communis agglutinin (RCA1), wheat germ agglutinin (WGA), concanavalin A (Con A), and lentil lectin (LcH), but not peanut agglutinin (PNA). P24 from NB cell spent medium did not bind to any of these lectins. The lectin affinity of P24 derived from lymphoblasts is consistent with the presence of N-linked oligosaccharide chains having N-acetyl glucosamine residues, a mannose core, and a terminal D-galactose. P24 from C-ALL cell spent medium was present in the 35-45% fraction of a saturated ammonium sulfate (SAS) partition of spent medium. The P24 antigen was detected in the fractionated plasma of five patients with C-ALL at the time of diagnosis and was undetectable when the patients had achieved a complete remission. Plasma from 2 patients with P24 negative ALL, normal human plasma, and normal human serum had no detectable activity.

  8. Hepatitis B Virus Core Protein Dephosphorylation Occurs during Pregenomic RNA Encapsidation.

    Science.gov (United States)

    Zhao, Qiong; Hu, Zhanying; Cheng, Junjun; Wu, Shuo; Luo, Yue; Chang, Jinhong; Hu, Jianming; Guo, Ju-Tao

    2018-07-01

    Hepatitis B virus (HBV) core protein consists of an N-terminal assembly domain and a C-terminal domain (CTD) with seven conserved serines or threonines that are dynamically phosphorylated/dephosphorylated during the viral replication cycle. Sulfamoylbenzamide derivatives are small molecular core protein allosteric modulators (CpAMs) that bind to the heteroaryldihydropyrimidine (HAP) pocket between the core protein dimer-dimer interfaces. CpAM binding alters the kinetics and pathway of capsid assembly and can result in the formation of morphologically "normal" capsids devoid of viral pregenomic RNA (pgRNA) and DNA polymerase. In order to investigate the mechanism underlying CpAM inhibition of pgRNA encapsidation, we developed an immunoblotting assay that can resolve core protein based on its phosphorylation status and demonstrated, for the first time, that core protein is hyperphosphorylated in free dimers and empty capsids from both mock-treated and CpAM-treated cells but is hypophosphorylated in pgRNA- and DNA-containing nucleocapsids. Interestingly, inhibition of pgRNA encapsidation by a heat shock protein 90 (HSP90) inhibitor prevented core protein dephosphorylation. Moreover, core proteins with point mutations at the wall of the HAP pocket, V124A and V124W, assembled empty capsids and nucleocapsids with altered phosphorylation status. The results thus suggest that core protein dephosphorylation occurs in the assembly of pgRNA and that interference with the interaction between core protein subunits at dimer-dimer interfaces during nucleocapsid assembly alters not only capsid structure, but also core protein dephosphorylation. Hence, inhibition of pgRNA encapsidation by CpAMs might be due to disruption of core protein dephosphorylation during nucleocapsid assembly. IMPORTANCE Dynamic phosphorylation of HBV core protein regulates multiple steps of viral replication. However, the regulatory function was mainly investigated by phosphomimetic mutagenesis, which

  9. Both core and F proteins of hepatitis C virus could enhance cell proliferation in transgenic mice

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Wen-Ta [Graduate Institute of Medical Biotechnology, Tzu Chi University, Hualien, Taiwan (China); Li, Hui-Chun [Department of Biochemistry, Tzu Chi University, Hualien, Taiwan (China); Lee, Shen-Kao; Ma, Hsin-Chieh; Yang, Chee-Hing; Chen, Hung-Ling [Graduate Institute of Medical Biotechnology, Tzu Chi University, Hualien, Taiwan (China); Lo, Shih-Yen, E-mail: losylo@mail.tcu.edu.tw [Graduate Institute of Medical Biotechnology, Tzu Chi University, Hualien, Taiwan (China); Department of Laboratory Medicine, Buddhist Tzu Chi General Hospital, Hualien, Taiwan (China)

    2013-05-24

    Highlights: •HCV core and F proteins could induce hepatocyte proliferation in the transgenic mice. •β-Catenin signaling pathway was activated by core protein in the transgenic mice. •β-Catenin signaling pathway was activated by myc-F protein in the transgenic mice. •Expression of SMA protein was enhanced by core but not myc-F protein. -- Abstract: The role of the protein encoded by the alternative open reading frame (ARF/F/core+1) of the Hepatitis C virus (HCV) genome in viral pathogenesis remains unknown. The different forms of ARF/F/core+1 protein were labile in cultured cells, a myc-tag fused at the N-terminus of the F protein made it more stable. To determine the role of core and F proteins in HCV pathogenesis, transgenic mice with either protein expression under the control of Albumin promoter were generated. Expression of core protein and F protein with myc tag (myc-F) could be detected by Western blotting analysis in the livers of these mice. The ratio of liver to body weight is increased for both core and myc-F transgenic mice compared to that of wild type mice. Indeed, the proliferating cell nuclear antigen protein, a proliferation marker, was up-regulated in the transgenic mice with core or myc-F protein. Further analyses by microarray and Western blotting suggested that β-catenin signaling pathway was activated by either core or myc-F protein in the transgenic mice. These transgenic mice were further treated with either Diethynitrosamine (a tumor initiator) or Phenobarbital (a tumor promoter). Phenobarbital but not Diethynitrosamine treatment could increase the liver/body weight ratio of these mice. However, no tumor formation was observed in these mice. In conclusion, HCV core and myc-F proteins could induce hepatocyte proliferation in the transgenic mice possibly through β-catenin signaling pathway.

  10. Both core and F proteins of hepatitis C virus could enhance cell proliferation in transgenic mice

    International Nuclear Information System (INIS)

    Hu, Wen-Ta; Li, Hui-Chun; Lee, Shen-Kao; Ma, Hsin-Chieh; Yang, Chee-Hing; Chen, Hung-Ling; Lo, Shih-Yen

    2013-01-01

    Highlights: •HCV core and F proteins could induce hepatocyte proliferation in the transgenic mice. •β-Catenin signaling pathway was activated by core protein in the transgenic mice. •β-Catenin signaling pathway was activated by myc-F protein in the transgenic mice. •Expression of SMA protein was enhanced by core but not myc-F protein. -- Abstract: The role of the protein encoded by the alternative open reading frame (ARF/F/core+1) of the Hepatitis C virus (HCV) genome in viral pathogenesis remains unknown. The different forms of ARF/F/core+1 protein were labile in cultured cells, a myc-tag fused at the N-terminus of the F protein made it more stable. To determine the role of core and F proteins in HCV pathogenesis, transgenic mice with either protein expression under the control of Albumin promoter were generated. Expression of core protein and F protein with myc tag (myc-F) could be detected by Western blotting analysis in the livers of these mice. The ratio of liver to body weight is increased for both core and myc-F transgenic mice compared to that of wild type mice. Indeed, the proliferating cell nuclear antigen protein, a proliferation marker, was up-regulated in the transgenic mice with core or myc-F protein. Further analyses by microarray and Western blotting suggested that β-catenin signaling pathway was activated by either core or myc-F protein in the transgenic mice. These transgenic mice were further treated with either Diethynitrosamine (a tumor initiator) or Phenobarbital (a tumor promoter). Phenobarbital but not Diethynitrosamine treatment could increase the liver/body weight ratio of these mice. However, no tumor formation was observed in these mice. In conclusion, HCV core and myc-F proteins could induce hepatocyte proliferation in the transgenic mice possibly through β-catenin signaling pathway

  11. The Expanded FindCore Method for Identification of a Core Atom Set for Assessment of Protein Structure Prediction

    Science.gov (United States)

    Snyder, David A.; Grullon, Jennifer; Huang, Yuanpeng J.; Tejero, Roberto; Montelione, Gaetano T.

    2014-01-01

    Maximizing the scientific impact of NMR-based structure determination requires robust and statistically sound methods for assessing the precision of NMR-derived structures. In particular, a method to define a core atom set for calculating superimpositions and validating structure predictions is critical to the use of NMR-derived structures as targets in the CASP competition. FindCore (D.A. Snyder and G.T. Montelione PROTEINS 2005;59:673–686) is a superimposition independent method for identifying a core atom set, and partitioning that set into domains. However, as FindCore optimizes superimposition by sensitively excluding not-well-defined atoms, the FindCore core may not comprise all atoms suitable for use in certain applications of NMR structures, including the CASP assessment process. Adapting the FindCore approach to assess predicted models against experimental NMR structures in CASP10 required modification of the FindCore method. This paper describes conventions and a standard protocol to calculate an “Expanded FindCore” atom set suitable for validation and application in biological and biophysical contexts. A key application of the Expanded FindCore method is to identify a core set of atoms in the experimental NMR structure for which it makes sense to validate predicted protein structure models. We demonstrate the application of this Expanded FindCore method in characterizing well-defined regions of 18 NMR-derived CASP10 target structures. The Expanded FindCore protocol defines “expanded core atom sets” that match an expert’s intuition of which parts of the structure are sufficiently well-defined to use in assessing CASP model predictions. We also illustrate the impact of this analysis on the CASP GDT assessment scores. PMID:24327305

  12. HCV core protein induces hepatic lipid accumulation by activating SREBP1 and PPARγ

    International Nuclear Information System (INIS)

    Kim, Kook Hwan; Hong, Sung Pyo; Kim, KyeongJin; Park, Min Jung; Kim, Kwang Jin; Cheong, JaeHun

    2007-01-01

    Hepatic steatosis is a common feature in patients with chronic hepatitis C virus (HCV) infection. HCV core protein plays an important role in the development of hepatic steatosis in HCV infection. Because SREBP1 (sterol regulatory element binding protein 1) and PPARγ (peroxisome proliferators-activated receptor γ) are involved in the regulation of lipid metabolism of hepatocyte, we sought to determine whether HCV core protein may impair the expression and activity of SREBP1 and PPARγ. In this study, it was demonstrated that HCV core protein increases the gene expression of SREBP1 not only in Chang liver, Huh7, and HepG2 cells transiently transfected with HCV core protein expression plasmid, but also in Chang liver-core stable cells. Furthermore, HCV core protein enhanced the transcriptional activity of SREBP1. In addition, HCV core protein elevated PPARγ transcriptional activity. However, HCV core protein had no effect on PPARγ gene expression. Finally, we showed that HCV core protein stimulates the genes expression of lipogenic enzyme and fatty acid uptake associated protein. Therefore, our finding provides a new insight into the mechanism of hepatic steatosis by HCV infection

  13. The retrovirus MA and PreTM proteins follow immature MVL cores

    DEFF Research Database (Denmark)

    Andersen, Klaus Bahl

    2013-01-01

    Detergent can dissolve retrovirus, exept the immature core. Here we show that the Matrix protein (MA) and the Transmembrane protein in its immature form (PreTM) bind to the retrovirus core. These attachments explain the attachment in the virus particle and the dynamics of the ability to fuse with...

  14. Identification of a functional, CRM-1-dependent nuclear export signal in hepatitis C virus core protein.

    Directory of Open Access Journals (Sweden)

    Andrea Cerutti

    Full Text Available Hepatitis C virus (HCV infection is a major cause of chronic liver disease worldwide. HCV core protein is involved in nucleocapsid formation, but it also interacts with multiple cytoplasmic and nuclear molecules and plays a crucial role in the development of liver disease and hepatocarcinogenesis. The core protein is found mostly in the cytoplasm during HCV infection, but also in the nucleus in patients with hepatocarcinoma and in core-transgenic mice. HCV core contains nuclear localization signals (NLS, but no nuclear export signal (NES has yet been identified.We show here that the aa(109-133 region directs the translocation of core from the nucleus to the cytoplasm by the CRM-1-mediated nuclear export pathway. Mutagenesis of the three hydrophobic residues (L119, I123 and L126 in the identified NES or in the sequence encoding the mature core aa(1-173 significantly enhanced the nuclear localisation of the corresponding proteins in transfected Huh7 cells. Both the NES and the adjacent hydrophobic sequence in domain II of core were required to maintain the core protein or its fragments in the cytoplasmic compartment. Electron microscopy studies of the JFH1 replication model demonstrated that core was translocated into the nucleus a few minutes after the virus entered the cell. The blockade of nucleocytoplasmic export by leptomycin B treatment early in infection led to the detection of core protein in the nucleus by confocal microscopy and coincided with a decrease in virus replication.Our data suggest that the functional NLS and NES direct HCV core protein shuttling between the cytoplasmic and nuclear compartments, with at least some core protein transported to the nucleus. These new properties of HCV core may be essential for virus multiplication and interaction with nuclear molecules, influence cell signaling and the pathogenesis of HCV infection.

  15. Identification of a functional, CRM-1-dependent nuclear export signal in hepatitis C virus core protein.

    Science.gov (United States)

    Cerutti, Andrea; Maillard, Patrick; Minisini, Rosalba; Vidalain, Pierre-Olivier; Roohvand, Farzin; Pecheur, Eve-Isabelle; Pirisi, Mario; Budkowska, Agata

    2011-01-01

    Hepatitis C virus (HCV) infection is a major cause of chronic liver disease worldwide. HCV core protein is involved in nucleocapsid formation, but it also interacts with multiple cytoplasmic and nuclear molecules and plays a crucial role in the development of liver disease and hepatocarcinogenesis. The core protein is found mostly in the cytoplasm during HCV infection, but also in the nucleus in patients with hepatocarcinoma and in core-transgenic mice. HCV core contains nuclear localization signals (NLS), but no nuclear export signal (NES) has yet been identified.We show here that the aa(109-133) region directs the translocation of core from the nucleus to the cytoplasm by the CRM-1-mediated nuclear export pathway. Mutagenesis of the three hydrophobic residues (L119, I123 and L126) in the identified NES or in the sequence encoding the mature core aa(1-173) significantly enhanced the nuclear localisation of the corresponding proteins in transfected Huh7 cells. Both the NES and the adjacent hydrophobic sequence in domain II of core were required to maintain the core protein or its fragments in the cytoplasmic compartment. Electron microscopy studies of the JFH1 replication model demonstrated that core was translocated into the nucleus a few minutes after the virus entered the cell. The blockade of nucleocytoplasmic export by leptomycin B treatment early in infection led to the detection of core protein in the nucleus by confocal microscopy and coincided with a decrease in virus replication.Our data suggest that the functional NLS and NES direct HCV core protein shuttling between the cytoplasmic and nuclear compartments, with at least some core protein transported to the nucleus. These new properties of HCV core may be essential for virus multiplication and interaction with nuclear molecules, influence cell signaling and the pathogenesis of HCV infection.

  16. HIV-1 p24(gag derived conserved element DNA vaccine increases the breadth of immune response in mice.

    Directory of Open Access Journals (Sweden)

    Viraj Kulkarni

    Full Text Available Viral diversity is considered a major impediment to the development of an effective HIV-1 vaccine. Despite this diversity, certain protein segments are nearly invariant across the known HIV-1 Group M sequences. We developed immunogens based on the highly conserved elements from the p24(gag region according to two principles: the immunogen must (i include strictly conserved elements of the virus that cannot mutate readily, and (ii exclude both HIV regions capable of mutating without limiting virus viability, and also immunodominant epitopes located in variable regions. We engineered two HIV-1 p24(gag DNA immunogens that express 7 highly Conserved Elements (CE of 12-24 amino acids in length and differ by only 1 amino acid in each CE ('toggle site', together covering >99% of the HIV-1 Group M sequences. Altering intracellular trafficking of the immunogens changed protein localization, stability, and also the nature of elicited immune responses. Immunization of C57BL/6 mice with p55(gag DNA induced poor, CD4(+ mediated cellular responses, to only 2 of the 7 CE; in contrast, vaccination with p24CE DNA induced cross-clade reactive, robust T cell responses to 4 of the 7 CE. The responses were multifunctional and composed of both CD4(+ and CD8(+ T cells with mature cytotoxic phenotype. These findings provide a method to increase immune response to universally conserved Gag epitopes, using the p24CE immunogen. p24CE DNA vaccination induced humoral immune responses similar in magnitude to those induced by p55(gag, which recognize the virus encoded p24(gag protein. The inclusion of DNA immunogens composed of conserved elements is a promising vaccine strategy to induce broader immunity by CD4(+ and CD8(+ T cells to additional regions of Gag compared to vaccination with p55(gag DNA, achieving maximal cross-clade reactive cellular and humoral responses.

  17. Bidirectional lipid droplet velocities are controlled by differential binding strengths of HCV core DII protein.

    Directory of Open Access Journals (Sweden)

    Rodney K Lyn

    Full Text Available Host cell lipid droplets (LD are essential in the hepatitis C virus (HCV life cycle and are targeted by the viral capsid core protein. Core-coated LDs accumulate in the perinuclear region and facilitate viral particle assembly, but it is unclear how mobility of these LDs is directed by core. Herein we used two-photon fluorescence, differential interference contrast imaging, and coherent anti-Stokes Raman scattering microscopies, to reveal novel core-mediated changes to LD dynamics. Expression of core protein's lipid binding domain II (DII-core induced slower LD speeds, but did not affect directionality of movement on microtubules. Modulating the LD binding strength of DII-core further impacted LD mobility, revealing the temporal effects of LD-bound DII-core. These results for DII-core coated LDs support a model for core-mediated LD localization that involves core slowing down the rate of movement of LDs until localization at the perinuclear region is accomplished where LD movement ceases. The guided localization of LDs by HCV core protein not only is essential to the viral life cycle but also poses an interesting target for the development of antiviral strategies against HCV.

  18. RNA chaperoning and intrinsic disorder in the core proteins of Flaviviridae.

    Science.gov (United States)

    Ivanyi-Nagy, Roland; Lavergne, Jean-Pierre; Gabus, Caroline; Ficheux, Damien; Darlix, Jean-Luc

    2008-02-01

    RNA chaperone proteins are essential partners of RNA in living organisms and viruses. They are thought to assist in the correct folding and structural rearrangements of RNA molecules by resolving misfolded RNA species in an ATP-independent manner. RNA chaperoning is probably an entropy-driven process, mediated by the coupled binding and folding of intrinsically disordered protein regions and the kinetically trapped RNA. Previously, we have shown that the core protein of hepatitis C virus (HCV) is a potent RNA chaperone that can drive profound structural modifications of HCV RNA in vitro. We now examined the RNA chaperone activity and the disordered nature of core proteins from different Flaviviridae genera, namely that of HCV, GBV-B (GB virus B), WNV (West Nile virus) and BVDV (bovine viral diarrhoea virus). Despite low-sequence similarities, all four proteins demonstrated general nucleic acid annealing and RNA chaperone activities. Furthermore, heat resistance of core proteins, as well as far-UV circular dichroism spectroscopy suggested that a well-defined 3D protein structure is not necessary for core-induced RNA structural rearrangements. These data provide evidence that RNA chaperoning-possibly mediated by intrinsically disordered protein segments-is conserved in Flaviviridae core proteins. Thus, besides nucleocapsid formation, core proteins may function in RNA structural rearrangements taking place during virus replication.

  19. HCV core protein promotes hepatocyte proliferation and chemoresistance by inhibiting NR4A1

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Yongsheng, E-mail: yongshengtanwhu@126.com; Li, Yan, E-mail: liyansd2@163.com

    2015-10-23

    This study investigated the effect of HCV core protein on the proliferation of hepatocytes and hepatocellular carcinoma cells (HCC), the influence of HCV core protein on HCC apoptosis induced by the chemotherapeutic agent cisplatin, and the mechanism through which HCV core protein acts as a potential oncoprotein in HCV-related HCC by measuring the levels of NR4A1 and Runt-related transcription factor 3 (RUNX3), which are associated with tumor suppression and chemotherapy resistance. In the present study, PcDNA3.1-core and RUNX3 siRNA were transfected into LO2 and HepG2 cells using Lipofectamine 2000. LO2-core, HepG2-core, LO2-RUNX3 {sup low} and control cells were treated with different concentrations of cisplatin for 72 h, and cell proliferation and apoptosis were assayed using the CellTiter 96{sup ®}Aqueous Non-Radioactive Cell Proliferation Assay Kit. Western blot and real time PCR analyses were used to detect NR4A1, RUNX3, smad7, Cyclin D1 and BAX. Confocal microscopy was used to determine the levels of NR4A1 in HepG2 and HepG2-core cells. The growth rate of HepG2-core cells was considerably greater than that of HepG2 cells. HCV core protein increased the expression of cyclin D1 and decreased the expressions of NR4A1 and RUNX3. In LO2 – RUNX3 {sup low}, the rate of cell proliferation and the level of cisplatin resistance were the same as in the LO2 -core. These results suggest that HCV core protein decreases the sensitivity of hepatocytes to cisplatin by inhibiting the expression of NR4A1 and promoting the expression of smad7, which negatively regulates the TGF-β pathway. This effect results in down regulation of RUNX3, a target of the TGF-β pathway. Taken together, these findings indicate that in hepatocytes, HCV core protein increases drug resistance and inhibits cell apoptosis by inhibiting the expressions of NR4A1 and RUNX3. - Highlights: • HCV core protein inhibits HepG2 cell sensitivity to cisplatin. • Core expression in HepG2 decreases

  20. HCV core protein promotes hepatocyte proliferation and chemoresistance by inhibiting NR4A1

    International Nuclear Information System (INIS)

    Tan, Yongsheng; Li, Yan

    2015-01-01

    This study investigated the effect of HCV core protein on the proliferation of hepatocytes and hepatocellular carcinoma cells (HCC), the influence of HCV core protein on HCC apoptosis induced by the chemotherapeutic agent cisplatin, and the mechanism through which HCV core protein acts as a potential oncoprotein in HCV-related HCC by measuring the levels of NR4A1 and Runt-related transcription factor 3 (RUNX3), which are associated with tumor suppression and chemotherapy resistance. In the present study, PcDNA3.1-core and RUNX3 siRNA were transfected into LO2 and HepG2 cells using Lipofectamine 2000. LO2-core, HepG2-core, LO2-RUNX3 "l"o"w and control cells were treated with different concentrations of cisplatin for 72 h, and cell proliferation and apoptosis were assayed using the CellTiter 96"®Aqueous Non-Radioactive Cell Proliferation Assay Kit. Western blot and real time PCR analyses were used to detect NR4A1, RUNX3, smad7, Cyclin D1 and BAX. Confocal microscopy was used to determine the levels of NR4A1 in HepG2 and HepG2-core cells. The growth rate of HepG2-core cells was considerably greater than that of HepG2 cells. HCV core protein increased the expression of cyclin D1 and decreased the expressions of NR4A1 and RUNX3. In LO2 – RUNX3 "l"o"w, the rate of cell proliferation and the level of cisplatin resistance were the same as in the LO2 -core. These results suggest that HCV core protein decreases the sensitivity of hepatocytes to cisplatin by inhibiting the expression of NR4A1 and promoting the expression of smad7, which negatively regulates the TGF-β pathway. This effect results in down regulation of RUNX3, a target of the TGF-β pathway. Taken together, these findings indicate that in hepatocytes, HCV core protein increases drug resistance and inhibits cell apoptosis by inhibiting the expressions of NR4A1 and RUNX3. - Highlights: • HCV core protein inhibits HepG2 cell sensitivity to cisplatin. • Core expression in HepG2 decreases expression of NR4A1

  1. Homogeneous protein analysis by magnetic core-shell nanorod probes

    KAUST Repository

    Schrittwieser, Stefan; Pelaz, Beatriz; Parak, Wolfgang J; Lentijo Mozo, Sergio; Soulantica, Katerina; Dieckhoff, Jan; Ludwig, Frank; Altantzis, Thomas; Bals, Sara; Schotter, Joerg

    2016-01-01

    analyte protein size. In addition, due to the locking of the optical signal to the magnetic excitation frequency, background signals are suppressed, thus allowing exclusive studies of processes at the nanoprobe surface only. We study target proteins

  2. The effect of HCV Core protein on the expression of miR-150

    Directory of Open Access Journals (Sweden)

    Sayad Khanizadeh

    2016-09-01

    Full Text Available Background : Hepatitis C virus (HCV is considered as one of the major pathogenic agents of chronic liver diseases. Previous studies have shown that HCV proteins can interaction with gene regulatory networks such as microRNAs. The aim of this study was to investigate the effect of HCV core protein on the expression of miR-150 in a cell culture model. Materials and Methods: Plasmids expressing full HCV core protein was transfected into Huh7 cell lines while a GFP expressing plasmid employed as negative control. Subsequently, total RNA extracted and Real-Time PCR performed to measure the expression level of miR-150 expression. Moreover, trypan blue exclusion assay was performed to investigate the effect of core protein on cell viability. Results: The gene expression analysis of miR-150 in Huh7 cells showed that endogenous HCV core protein could significantly down regulation of miR-150 when compared to GFP control plasmid and normal cells (P<0.01. Beside, core protein induced no significant proliferative or cytotoxic effects on hepatic cells as determined by trypan blue exclusion assay (P<0.05. Conclusion: Our study suggests that HCV core protein can led to down regulation of miR-150 expression. This data revealed that HCV protein interactions with cell regulatory machinery may contribute to pathogenesis of chronic liver diseases.

  3. Internalisation of hepatitis C virus core protein by human conjunctival fibroblasts.

    Science.gov (United States)

    Rajalakshmy, A R; Malathi, J; Madhavan, H N; Bhaskar, S; Iyer, G K

    2016-01-01

    Recent studies indicate that hepatitis C virus (HCV) proteins can mediate innate immune response and inflammation in conjunctival fibroblasts which contributes to the pathology of dry eye condition associated with chronic HCV infection. The present study investigates the phagocytic potential of human conjunctival fibroblasts (HCFj) for HCV core protein. HCFj cells were incubated with HCV core antigen for different periods of time, and fluorescent micrographs were taken to observe protein internalisation. HCFj cells were capable of internalising HCV core antigen within 1 h; this gives an insight into another molecular mechanism which may contribute towards HCV-associated conjunctival inflammation.

  4. Hepatitis C virus core protein potentiates proangiogenic activity of hepatocellular carcinoma cells.

    Science.gov (United States)

    Shao, Yu-Yun; Hsieh, Min-Shu; Wang, Han-Yu; Li, Yong-Shi; Lin, Hang; Hsu, Hung-Wei; Huang, Chung-Yi; Hsu, Chih-Hung; Cheng, Ann-Lii

    2017-10-17

    Increased angiogenic activity has been demonstrated in hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC), but the mechanism was unclear. To study the role of HCV core protein, we used tube formation and Matrigel plug assays to assess the proangiogenic activity of an HCC cell line, HuH7, and 2 of its stable clones-HuH7-core-high and HuH7-core-low, with high and low HCV core protein expression, respectively. In both assays, HuH7-core-high and HuH7-core-low cells dose-dependently induced stronger angiogenesis than control cells. HuH7 cells with HCV core protein expression showed increased mRNA and protein expression of vascular endothelial growth factor (VEGF). VEGF inhibition by bevacizumab reduced the proangiogenic activity of HuH7-core-high cells. The promotor region of VEGF contains the binding site of activator protein-1 (AP-1). Compared with controls, HuH7-core-high cells had an increased AP-1 activity and nuclear localization of phospho-c-jun. AP-1 inhibition using either RNA knockdown or AP-1 inhibitors reduced the VEGF mRNA expression and the proangiogenic activity of HuH7-core-high cells. Among 131 tissue samples from HCC patients, HCV-related HCC revealed stronger VEGF expression than did hepatitis B virus-related HCC. In conclusion, increased VEGF expression through AP-1 activation is a crucial mechanism underlying the proangiogenic activity of the HCV core protein in HCC cells.

  5. Quantitative analysis of the interaction between the envelope protein domains and the core protein of human hepatitis B virus

    International Nuclear Information System (INIS)

    Choi, Kyoung-Jae; Lim, Chun-Woo; Yoon, Moon-Young; Ahn, Byung-Yoon; Yu, Yeon Gyu

    2004-01-01

    Interaction between preformed nucleocapsids and viral envelope proteins is critical for the assembly of virus particles in infected cells. The pre-S1 and pre-S2 and cytosolic regions of the human hepatitis B virus envelope protein had been implicated in the interaction with the core protein of nucleocapsids. The binding affinities of specific subdomains of the envelope protein to the core protein were quantitatively measured by both ELISA and BIAcore assay. While a marginal binding was detected with the pre-S1 or pre-S2, the core protein showed high affinities to pre-S with apparent dissociation constants (K D app ) of 7.3 ± 0.9 and 8.2 ± 0.4 μM by ELISA and BIAcore assay, respectively. The circular dichroism analysis suggested that conformational change occurs in pre-S through interaction with core protein. These results substantiate the importance of specific envelope domains in virion assembly, and demonstrate that the interaction between viral proteins can be quantitatively measured in vitro

  6. P24 Plasma Physics Summer School 2012 Los Alamos National Laboratory Summer lecture series for students

    International Nuclear Information System (INIS)

    Intrator, Thomas P.; Bauer, Bruno; Fernandez, Juan C.; Daughton, William S.; Flippo, Kirk A.; Weber, Thomas; Awe, Thomas J.; Kim, Yong Ho

    2012-01-01

    This report covers the 2012 LANL summer lecture series for students. The lectures were: (1) Tom Intrator, P24 LANL: Kick off, Introduction - What is a plasma; (2) Bruno Bauer, Univ. Nevada-Reno: Derivation of plasma fluid equations; (3) Juan Fernandez, P24 LANL Overview of research being done in p-24; (4) Tom Intrator, P24 LANL: Intro to dynamo, reconnection, shocks; (5) Bill Daughton X-CP6 LANL: Intro to computational particle in cell methods; (6) Kirk Flippo, P24 LANL: High energy density plasmas; (7) Thom Weber, P24 LANL: Energy crisis, fission, fusion, non carbon fuel cycles; (8) Tom Awe, Sandia National Laboratory: Magneto Inertial Fusion; and (9) Yongho Kim, P24 LANL: Industrial technologies.

  7. P24 Plasma Physics Summer School 2012 Los Alamos National Laboratory Summer lecture series for students

    Energy Technology Data Exchange (ETDEWEB)

    Intrator, Thomas P. [Los Alamos National Laboratory; Bauer, Bruno [Univ Nevada, Reno; Fernandez, Juan C. [Los Alamos National Laboratory; Daughton, William S. [Los Alamos National Laboratory; Flippo, Kirk A. [Los Alamos National Laboratory; Weber, Thomas [Los Alamos National Laboratory; Awe, Thomas J. [Los Alamos National Laboratory; Kim, Yong Ho [Los Alamos National Laboratory

    2012-09-07

    This report covers the 2012 LANL summer lecture series for students. The lectures were: (1) Tom Intrator, P24 LANL: Kick off, Introduction - What is a plasma; (2) Bruno Bauer, Univ. Nevada-Reno: Derivation of plasma fluid equations; (3) Juan Fernandez, P24 LANL Overview of research being done in p-24; (4) Tom Intrator, P24 LANL: Intro to dynamo, reconnection, shocks; (5) Bill Daughton X-CP6 LANL: Intro to computational particle in cell methods; (6) Kirk Flippo, P24 LANL: High energy density plasmas; (7) Thom Weber, P24 LANL: Energy crisis, fission, fusion, non carbon fuel cycles; (8) Tom Awe, Sandia National Laboratory: Magneto Inertial Fusion; and (9) Yongho Kim, P24 LANL: Industrial technologies.

  8. Quantitative analysis of core fucosylation of serum proteins in liver diseases by LC-MS-MRM.

    Science.gov (United States)

    Ma, Junfeng; Sanda, Miloslav; Wei, Renhuizi; Zhang, Lihua; Goldman, Radoslav

    2018-02-07

    Aberrant core fucosylation of proteins has been linked to liver diseases. In this study, we carried out multiple reaction monitoring (MRM) quantification of core fucosylated N-glycopeptides of serum proteins partially deglycosylated by a combination of endoglycosidases (endoF1, endoF2, and endoF3). To minimize variability associated with the preparatory steps, the analysis was performed without enrichment of glycopeptides or fractionation of serum besides the nanoRP chromatography. Specifically, we quantified core fucosylation of 22 N-glycopeptides derived from 17 proteins together with protein abundance of these glycoproteins in a cohort of 45 participants (15 disease-free control, 15 fibrosis and 15 cirrhosis patients) using a multiplex nanoUPLC-MS-MRM workflow. We find increased core fucosylation of 5 glycopeptides at the stage of liver fibrosis (i.e., N630 of serotransferrin, N107 of alpha-1-antitrypsin, N253 of plasma protease C1 inhibitor, N397 of ceruloplasmin, and N86 of vitronectin), increase of additional 6 glycopeptides at the stage of cirrhosis (i.e., N138 and N762 of ceruloplasmin, N354 of clusterin, N187 of hemopexin, N71 of immunoglobulin J chain, and N127 of lumican), while the degree of core fucosylation of 10 glycopeptides did not change. Interestingly, although we observe an increase in the core fucosylation at N86 of vitronectin in liver fibrosis, core fucosylation decreases on the N169 glycopeptide of the same protein. Our results demonstrate that the changes in core fucosylation are protein and site specific during the progression of fibrotic liver disease and independent of the changes in the quantity of N-glycoproteins. It is expected that the fully optimized multiplex LC-MS-MRM assay of core fucosylated glycopeptides will be useful for the serologic assessment of the fibrosis of liver. We have quantified the difference in core fucosylation among three comparison groups (healthy control, fibrosis and cirrhosis patients) using a sensitive and

  9. Standardization of a cytometric p24-capture bead-assay for the detection of main HIV-1 subtypes.

    Science.gov (United States)

    Merbah, Mélanie; Onkar, Sayali; Grivel, Jean-Charles; Vanpouille, Christophe; Biancotto, Angélique; Bonar, Lydia; Sanders-Buell, Eric; Kijak, Gustavo; Michael, Nelson; Robb, Merlin; Kim, Jerome H; Tovanabutra, Sodsai; Chenine, Agnès-Laurence

    2016-04-01

    The prevailing method to assess HIV-1 replication and infectivity is to measure the production of p24 Gag protein by enzyme-linked immunosorbent assay (ELISA). Since fluorescent bead-based technologies offer a broader dynamic range and higher sensitivity, this study describes a p24 capture Luminex assay capable of detecting HIV-1 subtypes A-D, circulating recombinant forms (CRF) CRF01_AE and CRF02_AG, which together are responsible for over 90% of HIV-1 infections worldwide. The success of the assay lies in the identification and selection of a cross-reactive capture antibody (clone 183-H12-5C). Fifty-six isolates that belonged to six HIV-1 subtypes and CRFs were successfully detected with p-values below 0.021; limits of detection ranging from 3.7 to 3 × 104 pg/ml. The intra- and inter-assay variation gave coefficient of variations below 6 and 14%, respectively. The 183-bead Luminex assay also displayed higher sensitivity of 91% and 98% compared to commercial p24 ELISA and a previously described Luminex assay. The p24 concentrations measured by the 183-bead Luminex assay showed a significant correlation (R=0.92, passay leverages the advantages of the Luminex platform, which include smaller sample volume and simultaneous detection of up to 500 analytes in a single sample, and delivers a valuable tool for the field. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Detection of HIV-1 p24 Gag in plasma by a nanoparticle-based bio-barcode-amplification method.

    Science.gov (United States)

    Kim, Eun-Young; Stanton, Jennifer; Korber, Bette T M; Krebs, Kendall; Bogdan, Derek; Kunstman, Kevin; Wu, Samuel; Phair, John P; Mirkin, Chad A; Wolinsky, Steven M

    2008-06-01

    Detection of HIV-1 in patients is limited by the sensitivity and selectivity of available tests. The nanotechnology-based bio-barcode-amplification method offers an innovative approach to detect specific HIV-1 antigens from diverse HIV-1 subtypes. We evaluated the efficacy of this protein-detection method in detecting HIV-1 in men enrolled in the Chicago component of the Multicenter AIDS Cohort Study (MACS). The method relies on magnetic microparticles with antibodies that specifically bind the HIV-1 p24 Gag protein and nanoparticles that are encoded with DNA and antibodies that can sandwich the target protein captured by the microparticle-bound antibodies. The aggregate sandwich structures are magnetically separated from solution, and treated to remove the conjugated barcode DNA. The DNA barcodes (hundreds per target) were identified by a nanoparticle-based detection method that does not rely on PCR. Of 112 plasma samples from HIV-1-infected subjects, 111 were positive for HIV-1 p24 Gag protein (range: 0.11-71.5 ng/ml of plasma) by the bio-barcode-amplification method. HIV-1 p24 Gag protein was detected in only 23 out of 112 men by the conventional ELISA. A total of 34 uninfected subjects were negative by both tests. Thus, the specificity of the bio-barcode-amplification method was 100% and the sensitivity 99%. The bio-barcode-amplification method detected HIV-1 p24 Gag protein in plasma from all study subjects with less than 200 CD4(+) T cells/microl of plasma (100%) and 19 out of 20 (95%) HIV-1-infected men who had less than 50 copies/ml of plasma of HIV-1 RNA. In a separate group of 60 diverse international isolates, representative of clades A, B, C and D and circulating recombinant forms CRF01_AE and CRF02_AG, the bio-barcode-amplification method identified the presence of virus correctly. The bio-barcode-amplification method was superior to the conventional ELISA assay for the detection of HIV-1 p24 Gag protein in plasma with a breadth of coverage for diverse

  11. Hepatitis C virus core protein induces hepatic steatosis via Sirt1-dependent pathway.

    Science.gov (United States)

    Zhang, Chuanhai; Wang, Jingjing; Zhang, Hanlin; Liu, Shunai; Lee, Hyuek Jong; Jin, Wanzhu; Cheng, Jun

    2018-05-01

    Hepatic steatosis is a common feature of patients with chronic hepatitis C. Previous reports have shown that the overexpression of hepatitis C virus core-encoding sequences (hepatitis C virus genotypes 3a and 1b) significantly induces intracellular triglyceride accumulation. However, the underlying mechanism has not yet been revealed. To investigate whether Sirt1 is involved in hepatitis C virus-mediated hepatic steatosis, the overexpression of hepatitis C virus core 1b protein and Sirt1 and the knockdown of Sirt1 in HepG2 cells were performed. To confirm the results of the cellular experiment liver-specific Sirt1 KO mice with lentivirus-mediated hepatitis C virus core 1b overexpression were studied. Our results show that hepatitis C virus core 1b protein overexpression led to the accumulation of triglycerides in HepG2 cells. Notably the expression of PPARγ2 was dramatically increased at both the mRNA and protein levels by hepatitis C virus core 1b overexpression. The protein expression of Sirt1 is an upstream regulator of PPARγ2 and was also significantly increased after core 1b overexpression. In addition, the overexpression or knockdown of Sirt1 expression alone was sufficient to modulate p300-mediated PPARγ2 deacetylation. In vivo studies showed that hepatitis C virus core protein 1b-induced hepatic steatosis was attenuated in liver-specific Sirt1 KO mice by downregulation of PPARγ2 expression. Sirt1 mediates hepatitis C virus core protein 1b-induced hepatic steatosis by regulation of PPARγ2 expression. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Identifying protein complex by integrating characteristic of core-attachment into dynamic PPI network.

    Directory of Open Access Journals (Sweden)

    Xianjun Shen

    Full Text Available How to identify protein complex is an important and challenging task in proteomics. It would make great contribution to our knowledge of molecular mechanism in cell life activities. However, the inherent organization and dynamic characteristic of cell system have rarely been incorporated into the existing algorithms for detecting protein complexes because of the limitation of protein-protein interaction (PPI data produced by high throughput techniques. The availability of time course gene expression profile enables us to uncover the dynamics of molecular networks and improve the detection of protein complexes. In order to achieve this goal, this paper proposes a novel algorithm DCA (Dynamic Core-Attachment. It detects protein-complex core comprising of continually expressed and highly connected proteins in dynamic PPI network, and then the protein complex is formed by including the attachments with high adhesion into the core. The integration of core-attachment feature into the dynamic PPI network is responsible for the superiority of our algorithm. DCA has been applied on two different yeast dynamic PPI networks and the experimental results show that it performs significantly better than the state-of-the-art techniques in terms of prediction accuracy, hF-measure and statistical significance in biology. In addition, the identified complexes with strong biological significance provide potential candidate complexes for biologists to validate.

  13. Virus-producing cells determine the host protein profiles of HIV-1 virion cores

    Science.gov (United States)

    2012-01-01

    Background Upon HIV entry into target cells, viral cores are released and rearranged into reverse transcription complexes (RTCs), which support reverse transcription and also protect and transport viral cDNA to the site of integration. RTCs are composed of viral and cellular proteins that originate from both target and producer cells, the latter entering the target cell within the viral core. However, the proteome of HIV-1 viral cores in the context of the type of producer cells has not yet been characterized. Results We examined the proteomic profiles of the cores purified from HIV-1 NL4-3 virions assembled in Sup-T1 cells (T lymphocytes), PMA and vitamin D3 activated THP1 (model of macrophages, mMΦ), and non-activated THP1 cells (model of monocytes, mMN) and assessed potential involvement of identified proteins in the early stages of infection using gene ontology information and data from genome-wide screens on proteins important for HIV-1 replication. We identified 202 cellular proteins incorporated in the viral cores (T cells: 125, mMΦ: 110, mMN: 90) with the overlap between these sets limited to 42 proteins. The groups of RNA binding (29), DNA binding (17), cytoskeleton (15), cytoskeleton regulation (21), chaperone (18), vesicular trafficking-associated (12) and ubiquitin-proteasome pathway-associated proteins (9) were most numerous. Cores of the virions from SupT1 cells contained twice as many RNA binding proteins as cores of THP1-derived virus, whereas cores of virions from mMΦ and mMN were enriched in components of cytoskeleton and vesicular transport machinery, most probably due to differences in virion assembly pathways between these cells. Spectra of chaperones, cytoskeletal proteins and ubiquitin-proteasome pathway components were similar between viral cores from different cell types, whereas DNA-binding and especially RNA-binding proteins were highly diverse. Western blot analysis showed that within the group of overlapping proteins, the level of

  14. Identification of Protein Complexes Using Weighted PageRank-Nibble Algorithm and Core-Attachment Structure.

    Science.gov (United States)

    Peng, Wei; Wang, Jianxin; Zhao, Bihai; Wang, Lusheng

    2015-01-01

    Protein complexes play a significant role in understanding the underlying mechanism of most cellular functions. Recently, many researchers have explored computational methods to identify protein complexes from protein-protein interaction (PPI) networks. One group of researchers focus on detecting local dense subgraphs which correspond to protein complexes by considering local neighbors. The drawback of this kind of approach is that the global information of the networks is ignored. Some methods such as Markov Clustering algorithm (MCL), PageRank-Nibble are proposed to find protein complexes based on random walk technique which can exploit the global structure of networks. However, these methods ignore the inherent core-attachment structure of protein complexes and treat adjacent node equally. In this paper, we design a weighted PageRank-Nibble algorithm which assigns each adjacent node with different probability, and propose a novel method named WPNCA to detect protein complex from PPI networks by using weighted PageRank-Nibble algorithm and core-attachment structure. Firstly, WPNCA partitions the PPI networks into multiple dense clusters by using weighted PageRank-Nibble algorithm. Then the cores of these clusters are detected and the rest of proteins in the clusters will be selected as attachments to form the final predicted protein complexes. The experiments on yeast data show that WPNCA outperforms the existing methods in terms of both accuracy and p-value. The software for WPNCA is available at "http://netlab.csu.edu.cn/bioinfomatics/weipeng/WPNCA/download.html".

  15. HCV Core Protein Uses Multiple Mechanisms to Induce Oxidative Stress in Human Hepatoma Huh7 Cells

    Science.gov (United States)

    Ivanov, Alexander V.; Smirnova, Olga A.; Petrushanko, Irina Y.; Ivanova, Olga N.; Karpenko, Inna L.; Alekseeva, Ekaterina; Sominskaya, Irina; Makarov, Alexander A.; Bartosch, Birke; Kochetkov, Sergey N.; Isaguliants, Maria G.

    2015-01-01

    Hepatitis C virus (HCV) infection is accompanied by the induction of oxidative stress, mediated by several virus proteins, the most prominent being the nucleocapsid protein (HCV core). Here, using the truncated forms of HCV core, we have delineated several mechanisms by which it induces the oxidative stress. The N-terminal 36 amino acids of HCV core induced TGFβ1-dependent expression of nicotinamide adenine dinucleotide phosphate (NADPH) oxidases 1 and 4, both of which independently contributed to the production of reactive oxygen species (ROS). The same fragment also induced the expression of cyclo-oxygenase 2, which, however, made no input into ROS production. Amino acids 37–191 of HCV core up-regulated the transcription of a ROS generating enzyme cytochrome P450 2E1. Furthermore, the same fragment induced the expression of endoplasmic reticulum oxidoreductin 1α. The latter triggered efflux of Ca2+ from ER to mitochondria via mitochondrial Ca2+ uniporter, leading to generation of superoxide anions, and possibly also H2O2. Suppression of any of these pathways in cells expressing the full-length core protein led to a partial inhibition of ROS production. Thus, HCV core causes oxidative stress via several independent pathways, each mediated by a distinct region of the protein. PMID:26035647

  16. Shedding of leukemia-associated P24 antigen by lymphoblastoid cell lines.

    Science.gov (United States)

    Komada, Y; Ochiai, H; Shimizu, K; Azuma, E; Kamiya, H; Sakurai, M

    1987-12-01

    We report the development of a unique enzyme-linked immunosorbent assay (ELISA) which makes possible the detection of leukemia-associated P24 antigen, utilizing its ability to bind the Ricinus communis agglutinin (RCA1) and a monoclonal antibody, SJ-9A4 simultaneously. Using the RCA1/SJ-9A4-ELISA, P24 antigen, as few as 50 X 10(3) cells from a common acute lymphoblastic leukemia (C-ALL) cell line could be detected. The presence of D-galactose gave complete and specific inhibition of P24 antigen binding to RCA1. Matched concentrations of D-glucose and D-sucrose had no effect on binding. The release of the P24 antigen into the culture medium by a C-ALL cell line maintained at 37 degrees C could be detected; however, no P24 antigen was present in the culture medium when the cells were maintained at 4 degrees C. Sequential analysis of the culture medium for soluble P24 antigen revealed that release of the P24 antigen associated with cell growth. Molecular sieve chromatography of concentrated culture medium indicated that shed P24 antigen was eluted in the macromolecule fraction. P24 antigen was detected in the cerebrospinal fluid (CSF) of four patients with P24 positive ALL at the time of relapse of the central nervous system (CNS) and was undetectable while in complete remission. The CSF from three patients with P24 negative ALL and three patients with aseptic meningitis had no detectable activity.

  17. A critical role for protein degradation in the nucleus accumbens core in cocaine reward memory.

    Science.gov (United States)

    Ren, Zhen-Yu; Liu, Meng-Meng; Xue, Yan-Xue; Ding, Zeng-Bo; Xue, Li-Fen; Zhai, Suo-Di; Lu, Lin

    2013-04-01

    The intense associative memories that develop between cocaine-paired contexts and rewarding stimuli contribute to cocaine seeking and relapse. Previous studies have shown impairment in cocaine reward memories by manipulating a labile state induced by memory retrieval, but the mechanisms that underlie the destabilization of cocaine reward memory are unknown. In this study, using a Pavlovian cocaine-induced conditioned place preference (CPP) procedure in rats, we tested the contribution of ubiquitin-proteasome system-dependent protein degradation in destabilization of cocaine reward memory. First, we found that polyubiquitinated protein expression levels and polyubiquitinated N-ethylmaleimide-sensitive fusion (NSF) markedly increased 15 min after retrieval while NSF protein levels decreased 1 h after retrieval in the synaptosomal membrane fraction in the nucleus accumbens (NAc) core. We then found that infusion of the proteasome inhibitor lactacystin into the NAc core prevented the impairment of memory reconsolidation induced by the protein synthesis inhibitor anisomycin and reversed the effects of anisomycin on NSF and glutamate receptor 2 (GluR2) protein levels in the synaptosomal membrane fraction in the NAc core. We also found that lactacystin infusion into the NAc core but not into the shell immediately after extinction training sessions inhibited CPP extinction and reversed the extinction training-induced decrease in NSF and GluR2 in the synaptosomal membrane fraction in the NAc core. Finally, infusions of lactacystin by itself into the NAc core immediately after each training session or before the CPP retrieval test had no effect on the consolidation and retrieval of cocaine reward memory. These findings suggest that ubiquitin-proteasome system-dependent protein degradation is critical for retrieval-induced memory destabilization.

  18. Mitochondrial iron accumulation exacerbates hepatic toxicity caused by hepatitis C virus core protein

    Energy Technology Data Exchange (ETDEWEB)

    Sekine, Shuichi; Ito, Konomi; Watanabe, Haruna; Nakano, Takafumi [Laboratory of Biopharmaceutics, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675 (Japan); Moriya, Kyoji; Shintani, Yoshizumi; Fujie, Hajime; Tsutsumi, Takeya; Miyoshi, Hideyuki; Fujinaga, Hidetake; Shinzawa, Seiko; Koike, Kazuhiko [Department of Internal Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 (Japan); Horie, Toshiharu, E-mail: t.horie@thu.ac.jp [Laboratory of Biopharmaceutics, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675 (Japan)

    2015-02-01

    Patients with long-lasting hepatitis C virus (HCV) infection are at major risk of hepatocellular carcinoma (HCC). Iron accumulation in the livers of these patients is thought to exacerbate conditions of oxidative stress. Transgenic mice that express the HCV core protein develop HCC after the steatosis stage and produce an excess of hepatic reactive oxygen species (ROS). The overproduction of ROS in the liver is the net result of HCV core protein-induced dysfunction of the mitochondrial respiratory chain. This study examined the impact of ferric nitrilacetic acid (Fe-NTA)-mediated iron overload on mitochondrial damage and ROS production in HCV core protein-expressing HepG2 (human HCC) cells (Hep39b cells). A decrease in mitochondrial membrane potential and ROS production were observed following Fe-NTA treatment. After continuous exposure to Fe-NTA for six days, cell toxicity was observed in Hep39b cells, but not in mock (vector-transfected) HepG2 cells. Moreover, mitochondrial iron ({sup 59}Fe) uptake was increased in the livers of HCV core protein-expressing transgenic mice. This increase in mitochondrial iron uptake was inhibited by Ru360, a mitochondrial Ca{sup 2+} uniporter inhibitor. Furthermore, the Fe-NTA-induced augmentation of mitochondrial dysfunction, ROS production, and cell toxicity were also inhibited by Ru360 in Hep39b cells. Taken together, these results indicate that Ca{sup 2+} uniporter-mediated mitochondrial accumulation of iron exacerbates hepatocyte toxicity caused by the HCV core protein. - Highlights: • Iron accumulation in the livers of patients with hepatitis C virus (HCV) infection is thought to exacerbate oxidative stress. • The impact of iron overload on mitochondrial damage and ROS production in HCV core protein-expressing cells were examined. • Mitochondrial iron uptake was increased in the livers of HCV core protein-expressing transgenic mice. • Ca{sup 2+} uniporter-mediated mitochondrial accumulation of iron exacerbates

  19. Protein kinases responsible for the phosphorylation of the nuclear egress core complex of human cytomegalovirus.

    Science.gov (United States)

    Sonntag, Eric; Milbradt, Jens; Svrlanska, Adriana; Strojan, Hanife; Häge, Sigrun; Kraut, Alexandra; Hesse, Anne-Marie; Amin, Bushra; Sonnewald, Uwe; Couté, Yohann; Marschall, Manfred

    2017-10-01

    Nuclear egress of herpesvirus capsids is mediated by a multi-component nuclear egress complex (NEC) assembled by a heterodimer of two essential viral core egress proteins. In the case of human cytomegalovirus (HCMV), this core NEC is defined by the interaction between the membrane-anchored pUL50 and its nuclear cofactor, pUL53. NEC protein phosphorylation is considered to be an important regulatory step, so this study focused on the respective role of viral and cellular protein kinases. Multiply phosphorylated pUL50 varieties were detected by Western blot and Phos-tag analyses as resulting from both viral and cellular kinase activities. In vitro kinase analyses demonstrated that pUL50 is a substrate of both PKCα and CDK1, while pUL53 can also be moderately phosphorylated by CDK1. The use of kinase inhibitors further illustrated the importance of distinct kinases for core NEC phosphorylation. Importantly, mass spectrometry-based proteomic analyses identified five major and nine minor sites of pUL50 phosphorylation. The functional relevance of core NEC phosphorylation was confirmed by various experimental settings, including kinase knock-down/knock-out and confocal imaging, in which it was found that (i) HCMV core NEC proteins are not phosphorylated solely by viral pUL97, but also by cellular kinases; (ii) both PKC and CDK1 phosphorylation are detectable for pUL50; (iii) no impact of PKC phosphorylation on NEC functionality has been identified so far; (iv) nonetheless, CDK1-specific phosphorylation appears to be required for functional core NEC interaction. In summary, our findings provide the first evidence that the HCMV core NEC is phosphorylated by cellular kinases, and that the complex pattern of NEC phosphorylation has functional relevance.

  20. Preparation and recognition of surface molecularly imprinted core-shell microbeads for protein in aqueous solutions

    International Nuclear Information System (INIS)

    Lu Yan; Yan Changling; Gao Shuyan

    2009-01-01

    In this paper, a surface molecular imprinting technique was reported for preparing core-shell microbeads of protein imprinting, and bovine hemoglobin or bovine serum albumin were used as model proteins for studying the imprinted core-shell microbeads. 3-Aminophenylboronic acid (APBA) was polymerized onto the surface of polystyrene microbead in the presence of the protein templates to create protein-imprinted core-shell microbeads. The various samples were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) methods. The effect of pH on rebinding of the template hemoglobin, the specific binding and selective recognition were studied for the imprinted microbeads. The results show that the bovine hemoglobin-imprinted core-shell microbeads were successfully created. The shell was a sort of imprinted thin films with porous structure and larger surface areas. The imprinted microbeads have good selectivity for templates and high stability. Due to the recognition sites locating at or closing to the surface, these imprinted microbeads have good property of mass-transport. Unfortunately, the imprint technology was not successfully applied to imprinting bovine serum albumin (BSA).

  1. Preparation and recognition of surface molecularly imprinted core-shell microbeads for protein in aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Lu Yan, E-mail: yanlu2001@sohu.com [College of Chemistry and Environmental Science, Henan Normal University, 46 Jlanshe Road, Xinxiang 453007 (China); Yan Changling; Gao Shuyan [College of Chemistry and Environmental Science, Henan Normal University, 46 Jlanshe Road, Xinxiang 453007 (China)

    2009-04-01

    In this paper, a surface molecular imprinting technique was reported for preparing core-shell microbeads of protein imprinting, and bovine hemoglobin or bovine serum albumin were used as model proteins for studying the imprinted core-shell microbeads. 3-Aminophenylboronic acid (APBA) was polymerized onto the surface of polystyrene microbead in the presence of the protein templates to create protein-imprinted core-shell microbeads. The various samples were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) methods. The effect of pH on rebinding of the template hemoglobin, the specific binding and selective recognition were studied for the imprinted microbeads. The results show that the bovine hemoglobin-imprinted core-shell microbeads were successfully created. The shell was a sort of imprinted thin films with porous structure and larger surface areas. The imprinted microbeads have good selectivity for templates and high stability. Due to the recognition sites locating at or closing to the surface, these imprinted microbeads have good property of mass-transport. Unfortunately, the imprint technology was not successfully applied to imprinting bovine serum albumin (BSA).

  2. Characterization of the fusion core in zebrafish endogenous retroviral envelope protein

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Jian [State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072 (China); State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei 430071 (China); Zhang, Huaidong [CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei 430071 (China); Gong, Rui, E-mail: gongr@wh.iov.cn [CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei 430071 (China); Xiao, Gengfu, E-mail: xiaogf@wh.iov.cn [State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072 (China); State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei 430071 (China)

    2015-05-08

    Zebrafish endogenous retrovirus (ZFERV) is the unique endogenous retrovirus in zebrafish, as yet, containing intact open reading frames of its envelope protein gene in zebrafish genome. Similarly, several envelope proteins of endogenous retroviruses in human and other mammalian animal genomes (such as syncytin-1 and 2 in human, syncytin-A and B in mouse) were identified and shown to be functional in induction of cell–cell fusion involved in placental development. ZFERV envelope protein (Env) gene appears to be also functional in vivo because it is expressible. After sequence alignment, we found ZFERV Env shares similar structural profiles with syncytin and other type I viral envelopes, especially in the regions of N- and C-terminal heptad repeats (NHR and CHR) which were crucial for membrane fusion. We expressed the regions of N + C protein in the ZFERV Env (residues 459–567, including predicted NHR and CHR) to characterize the fusion core structure. We found N + C protein could form a stable coiled-coil trimer that consists of three helical NHR regions forming a central trimeric core, and three helical CHR regions packing into the grooves on the surface of the central core. The structural characterization of the fusion core revealed the possible mechanism of fusion mediated by ZFERV Env. These results gave comprehensive explanation of how the ancient virus infects the zebrafish and integrates into the genome million years ago, and showed a rational clue for discovery of physiological significance (e.g., medicate cell–cell fusion). - Highlights: • ZFERV Env shares similar structural profiles with syncytin and other type I viral envelopes. • The fusion core of ZFERV Env forms stable coiled-coil trimer including three NHRs and three CHRs. • The structural mechanism of viral entry mediated by ZFERV Env is disclosed. • The results are helpful for further discovery of physiological function of ZFERV Env in zebrafish.

  3. Analysis of core-periphery organization in protein contact networks reveals groups of structurally and functionally critical residues.

    Science.gov (United States)

    Isaac, Arnold Emerson; Sinha, Sitabhra

    2015-10-01

    The representation of proteins as networks of interacting amino acids, referred to as protein contact networks (PCN), and their subsequent analyses using graph theoretic tools, can provide novel insights into the key functional roles of specific groups of residues. We have characterized the networks corresponding to the native states of 66 proteins (belonging to different families) in terms of their core-periphery organization. The resulting hierarchical classification of the amino acid constituents of a protein arranges the residues into successive layers - having higher core order - with increasing connection density, ranging from a sparsely linked periphery to a densely intra-connected core (distinct from the earlier concept of protein core defined in terms of the three-dimensional geometry of the native state, which has least solvent accessibility). Our results show that residues in the inner cores are more conserved than those at the periphery. Underlining the functional importance of the network core, we see that the receptor sites for known ligand molecules of most proteins occur in the innermost core. Furthermore, the association of residues with structural pockets and cavities in binding or active sites increases with the core order. From mutation sensitivity analysis, we show that the probability of deleterious or intolerant mutations also increases with the core order. We also show that stabilization centre residues are in the innermost cores, suggesting that the network core is critically important in maintaining the structural stability of the protein. A publicly available Web resource for performing core-periphery analysis of any protein whose native state is known has been made available by us at http://www.imsc.res.in/ ~sitabhra/proteinKcore/index.html.

  4. Hepatitis C Virus Core Protein Modulates Endoglin (CD105) Signaling Pathway for Liver Pathogenesis.

    Science.gov (United States)

    Kwon, Young-Chan; Sasaki, Reina; Meyer, Keith; Ray, Ranjit

    2017-11-01

    Endoglin is part of the TGF-β receptor complex and has a crucial role in fibrogenesis and angiogenesis. It is also an important protein for tumor growth, survival, and cancer cell metastasis. In a previous study, we have shown that hepatitis C virus (HCV) infection induces epithelial-mesenchymal transition (EMT) state and cancer stem-like cell (CSC) properties in human hepatocytes. Our array data suggested that endoglin (CD105) mRNA is significantly upregulated in HCV-associated CSCs. In this study, we have observed increased endoglin expression on the cell surface of an HCV core-expressing hepatocellular carcinoma (HepG2) cell line or immortalized human hepatocytes (IHH) and activation of its downstream signaling molecules. The status of phospho-SMAD1/5 and the expression of inhibitor of DNA binding protein 1 (ID1) were upregulated in HCV-infected cells or viral core gene-transfected cells. Additionally, we observed upregulation of endoglin/ID1 mRNA expression in chronic HCV patient liver biopsy samples. CSC generation by HCV core protein was dependent on the endoglin signaling pathway using activin receptor-like kinase 1 (ALK1) Fc blocking peptide and endoglin small interfering RNA (siRNA). Further, follow-up from in vitro analysis suggested that the antiapoptosis Bcl2 protein, proliferation-related cyclin D1 protein, and CSC-associated Hes1, Notch1, Nanog, and Sox2 proteins are enhanced during infection or ectopic expression of HCV core protein. IMPORTANCE Endoglin plays a crucial role in fibrogenesis and angiogenesis and is an important protein for tumor growth, survival, and cancer cell metastasis. Endoglin enhances ALK1-SMAD1/5 signaling in different cell types, leading to increased proliferation and migration responses. We have observed endoglin expression on the HCV core-expressing cell surface of human hepatocyte origin and activation of phospho-SMAD1/5 and ID1 downstream signaling molecules. ID1 protein plays a role in CSC properties, and we found that

  5. Simultaneous inhibition of aberrant cancer kinome using rationally designed polymer-protein core-shell nanomedicine.

    Science.gov (United States)

    Chandran, Parwathy; Gupta, Neha; Retnakumari, Archana Payickattu; Malarvizhi, Giridharan Loghanathan; Keechilat, Pavithran; Nair, Shantikumar; Koyakutty, Manzoor

    2013-11-01

    Simultaneous inhibition of deregulated cancer kinome using rationally designed nanomedicine is an advanced therapeutic approach. Herein, we have developed a polymer-protein core-shell nanomedicine to inhibit critically aberrant pro-survival kinases (mTOR, MAPK and STAT5) in primitive (CD34(+)/CD38(-)) Acute Myeloid Leukemia (AML) cells. The nanomedicine consists of poly-lactide-co-glycolide core (~250 nm) loaded with mTOR inhibitor, everolimus, and albumin shell (~25 nm thick) loaded with MAPK/STAT5 inhibitor, sorafenib and the whole construct was surface conjugated with monoclonal antibody against CD33 receptor overexpressed in AML. Electron microscopy confirmed formation of core-shell nanostructure (~290 nm) and flow cytometry and confocal studies showed enhanced cellular uptake of targeted nanomedicine. Simultaneous inhibition of critical kinases causing synergistic lethality against leukemic cells, without affecting healthy blood cells, was demonstrated using immunoblotting, cytotoxicity and apoptosis assays. This cell receptor plus multi-kinase targeted core-shell nanomedicine was found better specific and tolerable compared to current clinical regime of cytarabine and daunorubicin. These authors demonstrate simultaneous inhibition of critical kinases causing synergistic lethality against leukemic cells, without affecting healthy blood cells by using rationally designed polymer-protein core-shell nanomedicine, provoding an advanced method to eliminate cancer cells, with the hope of future therapeutic use. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Dengue Virus Capsid Protein Binds Core Histones and Inhibits Nucleosome Formation in Human Liver Cells

    Science.gov (United States)

    Colpitts, Tonya M.; Barthel, Sebastian; Wang, Penghua; Fikrig, Erol

    2011-01-01

    Dengue virus (DENV) is a member of the Flaviviridae and a globally (re)emerging pathogen that causes serious human disease. There is no specific antiviral or vaccine for dengue virus infection. Flavivirus capsid (C) is a structural protein responsible for gathering the viral RNA into a nucleocapsid that forms the core of a mature virus particle. Flaviviral replication is known to occur in the cytoplasm yet a large portion of capsid protein localizes to the nucleus during infection. The reasons for the nuclear presences of capsid are not completely understood. Here, we expressed mature DENV C in a tandem affinity purification assay to identify potential binding partners in human liver cells. DENV C targeted the four core histones, H2A, H2B, H3 and H4. DENV C bound recombinant histones in solution and colocalized with histones in the nucleus and cytoplasm of liver cells during DENV infection. We show that DENV C acts as a histone mimic, forming heterodimers with core histones, binding DNA and disrupting nucleosome formation. We also demonstrate that DENV infection increases the amounts of core histones in livers cells, which may be a cellular response to C binding away the histone proteins. Infection with DENV additionally alters levels of H2A phosphorylation in a time-dependent manner. The interactions of C and histones add an interesting new role for the presence of C in the nucleus during DENV infection. PMID:21909430

  7. First principles design of a core bioenergetic transmembrane electron-transfer protein

    Energy Technology Data Exchange (ETDEWEB)

    Goparaju, Geetha; Fry, Bryan A.; Chobot, Sarah E.; Wiedman, Gregory; Moser, Christopher C.; Leslie Dutton, P.; Discher, Bohdana M.

    2016-05-01

    Here we describe the design, Escherichia coli expression and characterization of a simplified, adaptable and functionally transparent single chain 4-α-helix transmembrane protein frame that binds multiple heme and light activatable porphyrins. Such man-made cofactor-binding oxidoreductases, designed from first principles with minimal reference to natural protein sequences, are known as maquettes. This design is an adaptable frame aiming to uncover core engineering principles governing bioenergetic transmembrane electron-transfer function and recapitulate protein archetypes proposed to represent the origins of photosynthesis. This article is part of a Special Issue entitled Biodesign for Bioenergetics — the design and engineering of electronic transfer cofactors, proteins and protein networks, edited by Ronald L. Koder and J.L. Ross Anderson.

  8. Rift Valley fever phlebovirus NSs protein core domain structure suggests molecular basis for nuclear filaments.

    Science.gov (United States)

    Barski, Michal; Brennan, Benjamin; Miller, Ona K; Potter, Jane A; Vijayakrishnan, Swetha; Bhella, David; Naismith, James H; Elliott, Richard M; Schwarz-Linek, Ulrich

    2017-09-15

    Rift Valley fever phlebovirus (RVFV) is a clinically and economically important pathogen increasingly likely to cause widespread epidemics. RVFV virulence depends on the interferon antagonist non-structural protein (NSs), which remains poorly characterized. We identified a stable core domain of RVFV NSs (residues 83-248), and solved its crystal structure, a novel all-helical fold organized into highly ordered fibrils. A hallmark of RVFV pathology is NSs filament formation in infected cell nuclei. Recombinant virus encoding the NSs core domain induced intranuclear filaments, suggesting it contains all essential determinants for nuclear translocation and filament formation. Mutations of key crystal fibril interface residues in viruses encoding full-length NSs completely abrogated intranuclear filament formation in infected cells. We propose the fibrillar arrangement of the NSs core domain in crystals reveals the molecular basis of assembly of this key virulence factor in cell nuclei. Our findings have important implications for fundamental understanding of RVFV virulence.

  9. Viral control in chronic HIV-1 subtype C infection is associated with enrichment of p24 IgG1 with Fc effector activity.

    Science.gov (United States)

    Chung, Amy; Makuba, Jenniffer M; Ndlovu, Bongiwe; Licht, Anna; Robinson, Hannah; Ramlakhan, Yathisha; Ghebremichael, Musie; Reddy, Tarylee; Goulder, Philip; Walker, Bruce; Ndung'u, Thumbi; Alter, Galit

    2018-04-03

    Postinfection HIV viral control and immune correlates analysis of the RV144 vaccine trial indicate a potentially critical role for Fc receptor-mediated antibody functions. However, the influence of functional antibodies in clade C infection is largely unknown. Plasma samples from 361 chronic subtype C-infected, antiretroviral therapy-naïve participants were tested for their HIV-specific isotype and subclass distributions, along with their Fc receptor-mediated functional potential. Total IgG, IgG subclasses and IgA binding to p24 clade B/C and gp120 consensus C proteins were assayed by multiplex. Antibody-dependent uptake of antigen-coated beads and Fc receptor-mediated natural killer cell degranulation were evaluated as surrogates for antibody-dependent cellular phagocytosis (ADCP) and antibody-dependent cellular cytotoxicity (ADCC), respectively. p24 IgG1 was the only subclass associated with viral control (P = 0.01), with higher p24-specific ADCP and ADCC responses detected in individuals with high p24 IgG1. Although p24 IgG1 levels were enriched in patients with elevated Gag-specific T-cell responses, these levels remained an independent predictor of low-viral loads (P = 0.04) and high CD4 counts (P = 0.004) after adjusting for Gag-specific T-cell responses and for protective HLA class I alleles. p24 IgG1 levels independently predict viral control in HIV-1 clade C infection. Whether these responses contribute to direct antiviral control via the recruited killing of infected cells via the innate immune system or simply mark a qualitatively superior immune response to HIV, is uncertain, but highlights the role of p24-specific antibodies in control of clade C HIV-1 infection.

  10. Transformation of an Unclassified Myeloproliferative Neoplasm with a Rare BCR-JAK2 Fusion Transcript Resulting from the Translocation (9;22)(p24;q11)

    OpenAIRE

    A. N. Chamseddine; P. Etancelin; D. Penther; F. Parmentier; C. Kuadjovi; V. Camus; N. Contentin; P. Lenain; C. Bastard; H. Tilly; F. Jardin

    2015-01-01

    BCR-ABL1 negative myeloproliferative neoplasms (MPNs) are known to contain alterations of the tyrosine kinase JAK2 (located on 9p24) that result in constitutive activation of the encoded protein. JAK2 fusions are reported in acute and chronic leukemias of myeloid and lymphoid phenotypes. Here, we report an unclassified case of MPN (MPN-U) showing a t(9;22)(p24;q11), which generates a BCR-JAK2 fusion gene by fusing the BCR at intron 13 to JAK2 at intron 17 on the derivative chromosome 22. Most...

  11. A novel approach to preparing magnetic protein microspheres with core-shell structure

    International Nuclear Information System (INIS)

    Jiang Wei; Sun Zhendong; Li Fengsheng; Chen Kai; Liu Tianyu; Liu Jialing; Zhou Tianle; Guo Rui

    2011-01-01

    Magnetic protein microspheres with core-shell structure were prepared through a novel approach based on the sonochemical method and the emulsion solvent evaporation method. The microspheres are composed of the oleic acid and undecylenic acid modified Fe 3 O 4 cores and coated with globular bovine serum albumin (BSA). Under an optimized condition, up to 57.8 wt% of approximately 10 nm superparamagnetic Fe 3 O 4 nanoparticles could be uniformly encapsulated into the BSA microspheres with the diameter of approximately 160 nm and the high saturation magnetization of 38.5 emu/g, besides of the abundant functional groups. The possible formation mechanism of magnetic microspheres was discussed in detail. - Research Highlights: → Magnetic protein microspheres with core-shell structure were prepared through a novel approach based on the sonochemical method and the emulsion solvent evaporation method.→ The microspheres are composed of the oleic acid and undecylenic acid modified Fe 3 O 4 cores and coated with globular bovine serum albumin (BSA).→ 57.8 wt% of approximately 10 nm superparamagnetic Fe 3 O 4 nanoparticles could be uniformly encapsulated into the BSA microspheres with the diameter of approximately 160 nm and the high saturation magnetization of 38.5 emu/g, besides the abundant functional groups.

  12. A novel approach to preparing magnetic protein microspheres with core-shell structure

    Energy Technology Data Exchange (ETDEWEB)

    Jiang Wei, E-mail: climentjw@126.co [National Special Superfine Powder Engineering Research Center, Nanjing University of Science and Technology, Nanjing 210094 (China); Sun Zhendong; Li Fengsheng [National Special Superfine Powder Engineering Research Center, Nanjing University of Science and Technology, Nanjing 210094 (China); Chen Kai; Liu Tianyu; Liu Jialing [Department of Physics, Nanjing University of Science and Technology, Nanjing 210094 (China); Zhou Tianle [Department of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Guo Rui [Department of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China)

    2011-03-15

    Magnetic protein microspheres with core-shell structure were prepared through a novel approach based on the sonochemical method and the emulsion solvent evaporation method. The microspheres are composed of the oleic acid and undecylenic acid modified Fe{sub 3}O{sub 4} cores and coated with globular bovine serum albumin (BSA). Under an optimized condition, up to 57.8 wt% of approximately 10 nm superparamagnetic Fe{sub 3}O{sub 4} nanoparticles could be uniformly encapsulated into the BSA microspheres with the diameter of approximately 160 nm and the high saturation magnetization of 38.5 emu/g, besides of the abundant functional groups. The possible formation mechanism of magnetic microspheres was discussed in detail. - Research Highlights: Magnetic protein microspheres with core-shell structure were prepared through a novel approach based on the sonochemical method and the emulsion solvent evaporation method. The microspheres are composed of the oleic acid and undecylenic acid modified Fe{sub 3}O{sub 4} cores and coated with globular bovine serum albumin (BSA). 57.8 wt% of approximately 10 nm superparamagnetic Fe{sub 3}O{sub 4} nanoparticles could be uniformly encapsulated into the BSA microspheres with the diameter of approximately 160 nm and the high saturation magnetization of 38.5 emu/g, besides the abundant functional groups.

  13. Vaccine delivery system for tuberculosis based on nano-sized hepatitis B virus core protein particles

    Directory of Open Access Journals (Sweden)

    Dhanasooraj D

    2013-02-01

    Full Text Available Dhananjayan Dhanasooraj, R Ajay Kumar, Sathish MundayoorMycobacterium Research Group, Rajiv Gandhi Centre for Biotechnology, Kerala, IndiaAbstract: Nano-sized hepatitis B virus core virus-like particles (HBc-VLP are suitable for uptake by antigen-presenting cells. Mycobacterium tuberculosis antigen culture filtrate protein 10 (CFP-10 is an important vaccine candidate against tuberculosis. The purified antigen shows low immune response without adjuvant and tends to have low protective efficacy. The present study is based on the assumption that expression of these proteins on HBc nanoparticles would provide higher protection when compared to the native antigen alone. The cfp-10 gene was expressed as a fusion on the major immunodominant region of HBc-VLP, and the immune response in Balb/c mice was studied and compared to pure proteins, a mixture of antigens, and fusion protein-VLP, all without using any adjuvant. The humoral, cytokine, and splenocyte cell proliferation responses suggested that the HBc-VLP bearing CFP-10 generated an antigen-specific immune response in a Th1-dependent manner. By virtue of its self-adjuvant nature and ability to form nano-sized particles, HBc-VLPs are an excellent vaccine delivery system for use with subunit protein antigens identified in the course of recent vaccine research.Keywords: Mycobacterium tuberculosis, VLP, hepatitis B virus core particle, CFP-10, self-adjuvant, vaccine delivery

  14. Eficiencia de la respuesta superovulatoria del ganado Brahman al protocolo P-24

    OpenAIRE

    Roger Salgado O.; Andrés Mejía A.; Pablo Suárez S.

    2011-01-01

    Objetivo. Evaluar la eficiencia de la respuesta superovulatoria del ganado Brahman al protocolo P-24. Materiales y métodos. Se utilizaron doce vacas Brahman donadoras con más de 60 días postparto, a las cuales se les realizó un total de 21 tratamientos superovulatorios con base en el protocolo P-24. Se realizó la colecta de los embriones a través del método convencional y los embriones fueron clasificados (IETS). Resultados. Se obtuvo un promedio de 9.1 estructuras, 4.4 embriones transferible...

  15. Hepatitis C Virus core+1/ARF Protein Modulates the Cyclin D1/pRb Pathway and Promotes Carcinogenesis.

    Science.gov (United States)

    Moustafa, Savvina; Karakasiliotis, Ioannis; Mavromara, Penelope

    2018-05-01

    Viruses often encompass overlapping reading frames and unconventional translation mechanisms in order to maximize the output from a minimum genome and to orchestrate their timely gene expression. Hepatitis C virus (HCV) possesses such an unconventional open reading frame (ORF) within the core-coding region, encoding an additional protein, initially designated ARFP, F, or core+1. Two predominant isoforms of core+1/ARFP have been reported, core+1/L, initiating from codon 26, and core+1/S, initiating from codons 85/87 of the polyprotein coding region. The biological significance of core+1/ARFP expression remains elusive. The aim of the present study was to gain insight into the functional and pathological properties of core+1/ARFP through its interaction with the host cell, combining in vitro and in vivo approaches. Our data provide strong evidence that the core+1/ARFP of HCV-1a stimulates cell proliferation in Huh7-based cell lines expressing either core+1/S or core+1/L isoforms and in transgenic liver disease mouse models expressing core+1/S protein in a liver-specific manner. Both isoforms of core+1/ARFP increase the levels of cyclin D1 and phosphorylated Rb, thus promoting the cell cycle. In addition, core+1/S was found to enhance liver regeneration and oncogenesis in transgenic mice. The induction of the cell cycle together with increased mRNA levels of cell proliferation-related oncogenes in cells expressing the core+1/ARFP proteins argue for an oncogenic potential of these proteins and an important role in HCV-associated pathogenesis. IMPORTANCE This study sheds light on the biological importance of a unique HCV protein. We show here that core+1/ARFP of HCV-1a interacts with the host machinery, leading to acceleration of the cell cycle and enhancement of liver carcinogenesis. This pathological mechanism(s) may complement the action of other viral proteins with oncogenic properties, leading to the development of hepatocellular carcinoma. In addition, given that

  16. An α-Helical Core Encodes the Dual Functions of the Chlamydial Protein IncA*

    Science.gov (United States)

    Ronzone, Erik; Wesolowski, Jordan; Bauler, Laura D.; Bhardwaj, Anshul; Hackstadt, Ted; Paumet, Fabienne

    2014-01-01

    Chlamydia is an intracellular bacterium that establishes residence within parasitophorous compartments (inclusions) inside host cells. Chlamydial inclusions are uncoupled from the endolysosomal pathway and undergo fusion with cellular organelles and with each other. To do so, Chlamydia expresses proteins on the surface of the inclusion using a Type III secretion system. These proteins, termed Incs, are located at the interface between host and pathogen and carry out the functions necessary for Chlamydia survival. Among these Incs, IncA plays a critical role in both protecting the inclusion from lysosomal fusion and inducing the homotypic fusion of inclusions. Within IncA are two regions homologous to eukaryotic SNARE (soluble N-ethylmaleimide-sensitive factor attachment receptor) domains referred to as SNARE-like domain 1 (SLD1) and SNARE-like domain 2 (SLD2). Using a multidisciplinary approach, we have discovered the functional core of IncA that retains the ability to both inhibit SNARE-mediated fusion and promote the homotypic fusion of Chlamydia inclusions. Circular dichroism and analytical ultracentrifugation experiments show that this core region is composed almost entirely of α-helices and assembles into stable homodimers in solution. Altogether, we propose that both IncA functions are encoded in a structured core domain that encompasses SLD1 and part of SLD2. PMID:25324548

  17. An α-helical core encodes the dual functions of the chlamydial protein IncA.

    Science.gov (United States)

    Ronzone, Erik; Wesolowski, Jordan; Bauler, Laura D; Bhardwaj, Anshul; Hackstadt, Ted; Paumet, Fabienne

    2014-11-28

    Chlamydia is an intracellular bacterium that establishes residence within parasitophorous compartments (inclusions) inside host cells. Chlamydial inclusions are uncoupled from the endolysosomal pathway and undergo fusion with cellular organelles and with each other. To do so, Chlamydia expresses proteins on the surface of the inclusion using a Type III secretion system. These proteins, termed Incs, are located at the interface between host and pathogen and carry out the functions necessary for Chlamydia survival. Among these Incs, IncA plays a critical role in both protecting the inclusion from lysosomal fusion and inducing the homotypic fusion of inclusions. Within IncA are two regions homologous to eukaryotic SNARE (soluble N-ethylmaleimide-sensitive factor attachment receptor) domains referred to as SNARE-like domain 1 (SLD1) and SNARE-like domain 2 (SLD2). Using a multidisciplinary approach, we have discovered the functional core of IncA that retains the ability to both inhibit SNARE-mediated fusion and promote the homotypic fusion of Chlamydia inclusions. Circular dichroism and analytical ultracentrifugation experiments show that this core region is composed almost entirely of α-helices and assembles into stable homodimers in solution. Altogether, we propose that both IncA functions are encoded in a structured core domain that encompasses SLD1 and part of SLD2. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. PanCoreGen - Profiling, detecting, annotating protein-coding genes in microbial genomes.

    Science.gov (United States)

    Paul, Sandip; Bhardwaj, Archana; Bag, Sumit K; Sokurenko, Evgeni V; Chattopadhyay, Sujay

    2015-12-01

    A large amount of genomic data, especially from multiple isolates of a single species, has opened new vistas for microbial genomics analysis. Analyzing the pan-genome (i.e. the sum of genetic repertoire) of microbial species is crucial in understanding the dynamics of molecular evolution, where virulence evolution is of major interest. Here we present PanCoreGen - a standalone application for pan- and core-genomic profiling of microbial protein-coding genes. PanCoreGen overcomes key limitations of the existing pan-genomic analysis tools, and develops an integrated annotation-structure for a species-specific pan-genomic profile. It provides important new features for annotating draft genomes/contigs and detecting unidentified genes in annotated genomes. It also generates user-defined group-specific datasets within the pan-genome. Interestingly, analyzing an example-set of Salmonella genomes, we detect potential footprints of adaptive convergence of horizontally transferred genes in two human-restricted pathogenic serovars - Typhi and Paratyphi A. Overall, PanCoreGen represents a state-of-the-art tool for microbial phylogenomics and pathogenomics study. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. PanCoreGen – profiling, detecting, annotating protein-coding genes in microbial genomes

    Science.gov (United States)

    Bhardwaj, Archana; Bag, Sumit K; Sokurenko, Evgeni V.

    2015-01-01

    A large amount of genomic data, especially from multiple isolates of a single species, has opened new vistas for microbial genomics analysis. Analyzing pan-genome (i.e. the sum of genetic repertoire) of microbial species is crucial in understanding the dynamics of molecular evolution, where virulence evolution is of major interest. Here we present PanCoreGen – a standalone application for pan- and core-genomic profiling of microbial protein-coding genes. PanCoreGen overcomes key limitations of the existing pan-genomic analysis tools, and develops an integrated annotation-structure for species-specific pan-genomic profile. It provides important new features for annotating draft genomes/contigs and detecting unidentified genes in annotated genomes. It also generates user-defined group-specific datasets within the pan-genome. Interestingly, analyzing an example-set of Salmonella genomes, we detect potential footprints of adaptive convergence of horizontally transferred genes in two human-restricted pathogenic serovars – Typhi and Paratyphi A. Overall, PanCoreGen represents a state-of-the-art tool for microbial phylogenomics and pathogenomics study. PMID:26456591

  20. Characterization of a recurrent t(1;2)(p36;p24) in human uterine leiomyoma.

    NARCIS (Netherlands)

    Rijk, A. van; Sweers, M.A.; Huys, E.; Kersten, M.; Merkx, G.F.M.; Geurts van Kessel, A.H.M.; Debiec-Rychter, M.; Schoenmakers, E.F.P.M.

    2009-01-01

    Uterine leiomyomas are the most common neoplasms in women of reproductive age. Approximately 40% of these neoplasms show recurring structural cytogenetic anomalies, including del(7)(q22), t(12;14)(q15;q24), t(1;2)(p36;p24), and anomalies affecting 6p21 or 10q22. Using positional cloning strategies,

  1. A novel approach to preparing magnetic protein microspheres with core-shell structure

    Science.gov (United States)

    Jiang, Wei; Sun, Zhendong; Li, Fengsheng; Chen, Kai; Liu, Tianyu; Liu, Jialing; Zhou, Tianle; Guo, Rui

    2011-03-01

    Magnetic protein microspheres with core-shell structure were prepared through a novel approach based on the sonochemical method and the emulsion solvent evaporation method. The microspheres are composed of the oleic acid and undecylenic acid modified Fe 3O 4 cores and coated with globular bovine serum albumin (BSA). Under an optimized condition, up to 57.8 wt% of approximately 10 nm superparamagnetic Fe 3O 4 nanoparticles could be uniformly encapsulated into the BSA microspheres with the diameter of approximately 160 nm and the high saturation magnetization of 38.5 emu/g, besides of the abundant functional groups. The possible formation mechanism of magnetic microspheres was discussed in detail.

  2. TRF2 Protein Interacts with Core Histones to Stabilize Chromosome Ends*

    Science.gov (United States)

    Izumi, Takashi; Shimizu, Shigeomi

    2016-01-01

    Mammalian chromosome ends are protected by a specialized nucleoprotein complex called telomeres. Both shelterin, a telomere-specific multi-protein complex, and higher order telomeric chromatin structures combine to stabilize the chromosome ends. Here, we showed that TRF2, a component of shelterin, binds to core histones to protect chromosome ends from inappropriate DNA damage response and loss of telomeric DNA. The N-terminal Gly/Arg-rich domain (GAR domain) of TRF2 directly binds to the globular domain of core histones. The conserved arginine residues in the GAR domain of TRF2 are required for this interaction. A TRF2 mutant with these arginine residues substituted by alanine lost the ability to protect telomeres and induced rapid telomere shortening caused by the cleavage of a loop structure of the telomeric chromatin. These findings showed a previously unnoticed interaction between the shelterin complex and nucleosomal histones to stabilize the chromosome ends. PMID:27514743

  3. Controlled-release and preserved bioactivity of proteins from (self-assembled core-shell double-walled microspheres

    Directory of Open Access Journals (Sweden)

    Yuan W

    2012-01-01

    Full Text Available Weien Yuan1,2, Zhenguo Liu11Department of Neurology, Xinhua Hospital, affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 2School of Pharmacy, Shanghai Jiao Tong University, Shanghai, People’s Republic of ChinaAbstract: In order to address preserved protein bioactivities and protein sustained-release problems, a method for preparing double-walled microspheres with a core (protein-loaded nanoparticles with a polymer-suspended granule system-formed core and a second shell (a polymer-formed shell for controlled drug release and preserved protein bioactivities has been developed using (solid-in-oil phase-in-hydrophilic oil-in-water (S/O/Oh/W phases. The method, based on our previous microsphere preparation method (solid-in-oil phase-in-hydrophilic oil-in-water (S/O/Oh/W, employs different concentric poly(D,L-lactide-co-glycolide, poly(D,L-lactide, and protein-loaded nanoparticles to produce a suspended liquid which then self-assembles to form shell-core microspheres in the hydrophilic oil phase, which are then solidified in the water phase. Variations in the preparation parameters allowed complete encapsulation by the shell phase, including the efficient formation of a poly(D,L-lactide shell encapsulating a protein-loaded nanoparticle-based poly(D,L-lactide-co-glycolide core. This method produces core-shell double-walled microspheres that show controlled protein release and preserved protein bioactivities for 60 days. Based upon these results, we concluded that the core-shell double-walled microspheres might be applied for tissue engineering and therapy for chronic diseases, etc.Keywords: protein delivery, protein stability, core-shell microspheres, dextran nanoparticles

  4. p24 as a predictor of mortality in a cohort of HIV-1-infected adults in rural Africa

    DEFF Research Database (Denmark)

    Erikstrup, C.; Kallestrup, P.; Zinyama-Gutsire, R.B.

    2008-01-01

    in a cohort of HIV-1-infected individuals in Zimbabwe. METHODS: Treatment-naive HIV-1-infected individuals (n=198) from the Mupfure Schistosomiasis and HIV Cohort were followed until death or censoring (3-4.3 years). At baseline, p24, HIV-RNA, CD4 cell counts, and clinical staging (Centers for Disease Control...... and Prevention classification) were assessed. RESULTS: p24 correlated with HIV-RNA (PDisease Control and Prevention category (P... regression. p24 predicted mortality in univariate Cox analysis (Pstudy to evaluate the prognostic strength of p24 in an area with a predominance of HIV subtype C infections. p24 correlated...

  5. Structural characterization of the fusion core in syncytin, envelope protein of human endogenous retrovirus family W

    International Nuclear Information System (INIS)

    Gong Rui; Peng Xiaoxue; Kang Shuli; Feng Huixing; Huang Jianying; Zhang Wentao; Lin Donghai; Tien Po; Xiao Gengfu

    2005-01-01

    Syncytin is a captive retroviral envelope protein, possibly involved in the formation of the placental syncytiotrophoblast layer generated by trophoblast cell fusion at the maternal-fetal interface. We found that syncytin and type I viral envelope proteins shared similar structural profiling, especially in the regions of N- and C-terminal heptad repeats (NHR and CHR). We expressed the predicted regions of NHR (41 aa) and CHR (34 aa) in syncytin as a native single chain (named 2-helix protein) to characterize it. 2-helix protein exists as a trimer and is highly α-helix, thermo-stable, and denatured by low pH. NHR and CHR could form a protease-resistant complex. The complex structure built by the molecular docking demonstrated that NHR and CHR associated in an antiparallel manner. Overall, the 2-helix protein could form a thermo-stable coiled coil trimer. The fusion core structure of syncytin was first demonstrated in endogenous retrovirus. These results support the explanation how syncytin mediates cytotrophoblast cell fusion involved in placental morphogenesis

  6. HBV core protein allosteric modulators differentially alter cccDNA biosynthesis from de novo infection and intracellular amplification pathways

    Science.gov (United States)

    Guo, Fang; Zhao, Qiong; Cheng, Junjun; Qi, Yonghe; Su, Qing; Wei, Lai; Li, Wenhui; Chang, Jinhong

    2017-01-01

    Hepatitis B virus (HBV) core protein assembles viral pre-genomic (pg) RNA and DNA polymerase into nucleocapsids for reverse transcriptional DNA replication to take place. Several chemotypes of small molecules, including heteroaryldihydropyrimidines (HAPs) and sulfamoylbenzamides (SBAs), have been discovered to allosterically modulate core protein structure and consequentially alter the kinetics and pathway of core protein assembly, resulting in formation of irregularly-shaped core protein aggregates or “empty” capsids devoid of pre-genomic RNA and viral DNA polymerase. Interestingly, in addition to inhibiting nucleocapsid assembly and subsequent viral genome replication, we have now demonstrated that HAPs and SBAs differentially modulate the biosynthesis of covalently closed circular (ccc) DNA from de novo infection and intracellular amplification pathways by inducing disassembly of nucleocapsids derived from virions as well as double-stranded DNA-containing progeny nucleocapsids in the cytoplasm. Specifically, the mistimed cuing of nucleocapsid uncoating prevents cccDNA formation during de novo infection of hepatocytes, while transiently accelerating cccDNA synthesis from cytoplasmic progeny nucleocapsids. Our studies indicate that elongation of positive-stranded DNA induces structural changes of nucleocapsids, which confers ability of mature nucleocapsids to bind CpAMs and triggers its disassembly. Understanding the molecular mechanism underlying the dual effects of the core protein allosteric modulators on nucleocapsid assembly and disassembly will facilitate the discovery of novel core protein-targeting antiviral agents that can more efficiently suppress cccDNA synthesis and cure chronic hepatitis B. PMID:28945802

  7. HBV core protein allosteric modulators differentially alter cccDNA biosynthesis from de novo infection and intracellular amplification pathways.

    Science.gov (United States)

    Guo, Fang; Zhao, Qiong; Sheraz, Muhammad; Cheng, Junjun; Qi, Yonghe; Su, Qing; Cuconati, Andrea; Wei, Lai; Du, Yanming; Li, Wenhui; Chang, Jinhong; Guo, Ju-Tao

    2017-09-01

    Hepatitis B virus (HBV) core protein assembles viral pre-genomic (pg) RNA and DNA polymerase into nucleocapsids for reverse transcriptional DNA replication to take place. Several chemotypes of small molecules, including heteroaryldihydropyrimidines (HAPs) and sulfamoylbenzamides (SBAs), have been discovered to allosterically modulate core protein structure and consequentially alter the kinetics and pathway of core protein assembly, resulting in formation of irregularly-shaped core protein aggregates or "empty" capsids devoid of pre-genomic RNA and viral DNA polymerase. Interestingly, in addition to inhibiting nucleocapsid assembly and subsequent viral genome replication, we have now demonstrated that HAPs and SBAs differentially modulate the biosynthesis of covalently closed circular (ccc) DNA from de novo infection and intracellular amplification pathways by inducing disassembly of nucleocapsids derived from virions as well as double-stranded DNA-containing progeny nucleocapsids in the cytoplasm. Specifically, the mistimed cuing of nucleocapsid uncoating prevents cccDNA formation during de novo infection of hepatocytes, while transiently accelerating cccDNA synthesis from cytoplasmic progeny nucleocapsids. Our studies indicate that elongation of positive-stranded DNA induces structural changes of nucleocapsids, which confers ability of mature nucleocapsids to bind CpAMs and triggers its disassembly. Understanding the molecular mechanism underlying the dual effects of the core protein allosteric modulators on nucleocapsid assembly and disassembly will facilitate the discovery of novel core protein-targeting antiviral agents that can more efficiently suppress cccDNA synthesis and cure chronic hepatitis B.

  8. HBV core protein allosteric modulators differentially alter cccDNA biosynthesis from de novo infection and intracellular amplification pathways.

    Directory of Open Access Journals (Sweden)

    Fang Guo

    2017-09-01

    Full Text Available Hepatitis B virus (HBV core protein assembles viral pre-genomic (pg RNA and DNA polymerase into nucleocapsids for reverse transcriptional DNA replication to take place. Several chemotypes of small molecules, including heteroaryldihydropyrimidines (HAPs and sulfamoylbenzamides (SBAs, have been discovered to allosterically modulate core protein structure and consequentially alter the kinetics and pathway of core protein assembly, resulting in formation of irregularly-shaped core protein aggregates or "empty" capsids devoid of pre-genomic RNA and viral DNA polymerase. Interestingly, in addition to inhibiting nucleocapsid assembly and subsequent viral genome replication, we have now demonstrated that HAPs and SBAs differentially modulate the biosynthesis of covalently closed circular (ccc DNA from de novo infection and intracellular amplification pathways by inducing disassembly of nucleocapsids derived from virions as well as double-stranded DNA-containing progeny nucleocapsids in the cytoplasm. Specifically, the mistimed cuing of nucleocapsid uncoating prevents cccDNA formation during de novo infection of hepatocytes, while transiently accelerating cccDNA synthesis from cytoplasmic progeny nucleocapsids. Our studies indicate that elongation of positive-stranded DNA induces structural changes of nucleocapsids, which confers ability of mature nucleocapsids to bind CpAMs and triggers its disassembly. Understanding the molecular mechanism underlying the dual effects of the core protein allosteric modulators on nucleocapsid assembly and disassembly will facilitate the discovery of novel core protein-targeting antiviral agents that can more efficiently suppress cccDNA synthesis and cure chronic hepatitis B.

  9. Structure of the protein core of the glypican Dally-like and localization of a region important for hedgehog signaling

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Min-Sung; Saunders, Adam M.; Hamaoka, Brent Y.; Beachy, Philip A.; Leahy, Daniel J. (Stanford-MED); (JHU)

    2011-09-20

    Glypicans are heparan sulfate proteoglycans that modulate the signaling of multiple growth factors active during animal development, and loss of glypican function is associated with widespread developmental abnormalities. Glypicans consist of a conserved, approximately 45-kDa N-terminal protein core region followed by a stalk region that is tethered to the cell membrane by a glycosyl-phosphatidylinositol anchor. The stalk regions are predicted to be random coil but contain a variable number of attachment sites for heparan sulfate chains. Both the N-terminal protein core and the heparan sulfate attachments are important for glypican function. We report here the 2.4-{angstrom} crystal structure of the N-terminal protein core region of the Drosophila glypican Dally-like (Dlp). This structure reveals an elongated, {alpha}-helical fold for glypican core regions that does not appear homologous to any known structure. The Dlp core protein is required for normal responsiveness to Hedgehog (Hh) signals, and we identify a localized region on the Dlp surface important for mediating its function in Hh signaling. Purified Dlp protein core does not, however, interact appreciably with either Hh or an Hh:Ihog complex.

  10. An evolutionarily conserved glycine-tyrosine motif forms a folding core in outer membrane proteins.

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    Marcin Michalik

    Full Text Available An intimate interaction between a pair of amino acids, a tyrosine and glycine on neighboring β-strands, has been previously reported to be important for the structural stability of autotransporters. Here, we show that the conservation of this interacting pair extends to nearly all major families of outer membrane β-barrel proteins, which are thought to have originated through duplication events involving an ancestral ββ hairpin. We analyzed the function of this motif using the prototypical outer membrane protein OmpX. Stopped-flow fluorescence shows that two folding processes occur in the millisecond time regime, the rates of which are reduced in the tyrosine mutant. Folding assays further demonstrate a reduction in the yield of folded protein for the mutant compared to the wild-type, as well as a reduction in thermal stability. Taken together, our data support the idea of an evolutionarily conserved 'folding core' that affects the folding, membrane insertion, and thermal stability of outer membrane protein β-barrels.

  11. Human Adenovirus Core Protein V Is Targeted by the Host SUMOylation Machinery To Limit Essential Viral Functions.

    Science.gov (United States)

    Freudenberger, Nora; Meyer, Tina; Groitl, Peter; Dobner, Thomas; Schreiner, Sabrina

    2018-02-15

    Human adenoviruses (HAdV) are nonenveloped viruses containing a linear, double-stranded DNA genome surrounded by an icosahedral capsid. To allow proper viral replication, the genome is imported through the nuclear pore complex associated with viral core proteins. Until now, the role of these incoming virion proteins during the early phase of infection was poorly understood. The core protein V is speculated to bridge the core and the surrounding capsid. It binds the genome in a sequence-independent manner and localizes in the nucleus of infected cells, accumulating at nucleoli. Here, we show that protein V contains conserved SUMO conjugation motifs (SCMs). Mutation of these consensus motifs resulted in reduced SUMOylation of the protein; thus, protein V represents a novel target of the host SUMOylation machinery. To understand the role of protein V SUMO posttranslational modification during productive HAdV infection, we generated a replication-competent HAdV with SCM mutations within the protein V coding sequence. Phenotypic analyses revealed that these SCM mutations are beneficial for adenoviral replication. Blocking protein V SUMOylation at specific sites shifts the onset of viral DNA replication to earlier time points during infection and promotes viral gene expression. Simultaneously, the altered kinetics within the viral life cycle are accompanied by more efficient proteasomal degradation of host determinants and increased virus progeny production than that observed during wild-type infection. Taken together, our studies show that protein V SUMOylation reduces virus growth; hence, protein V SUMOylation represents an important novel aspect of the host antiviral strategy to limit virus replication and thereby points to potential intervention strategies. IMPORTANCE Many decades of research have revealed that HAdV structural proteins promote viral entry and mainly physical stability of the viral genome in the capsid. Our work over the last years showed that this

  12. Hepatitis B virus core protein allosteric modulators can distort and disrupt intact capsids.

    Science.gov (United States)

    Schlicksup, Christopher John; Wang, Joseph Che-Yen; Francis, Samson; Venkatakrishnan, Balasubramanian; Turner, William W; VanNieuwenhze, Michael; Zlotnick, Adam

    2018-01-29

    Defining mechanisms of direct-acting antivirals facilitates drug development and our understanding of virus function. Heteroaryldihydropyrimidines (HAPs) inappropriately activate assembly of hepatitis B virus (HBV) core protein (Cp), suppressing formation of virions. We examined a fluorophore-labeled HAP, HAP-TAMRA. HAP-TAMRA induced Cp assembly and also bound pre-assembled capsids. Kinetic and spectroscopic studies imply that HAP-binding sites are usually not available but are bound cooperatively. Using cryo-EM, we observed that HAP-TAMRA asymmetrically deformed capsids, creating a heterogeneous array of sharp angles, flat regions, and outright breaks. To achieve high resolution reconstruction (HAP-TAMRA caused quasi-sixfold vertices to become flatter and fivefold more angular. This transition led to asymmetric faceting. That a disordered crosslink could rescue symmetry implies that capsids have tensegrity properties. Capsid distortion and disruption is a new mechanism by which molecules like the HAPs can block HBV infection. © 2017, Schlicksup et al.

  13. Hepatitis B virus core protein allosteric modulators can distort and disrupt intact capsids

    Science.gov (United States)

    Schlicksup, Christopher John; Wang, Joseph Che-Yen; Francis, Samson; Venkatakrishnan, Balasubramanian; Turner, William W; VanNieuwenhze, Michael

    2018-01-01

    Defining mechanisms of direct-acting antivirals facilitates drug development and our understanding of virus function. Heteroaryldihydropyrimidines (HAPs) inappropriately activate assembly of hepatitis B virus (HBV) core protein (Cp), suppressing formation of virions. We examined a fluorophore-labeled HAP, HAP-TAMRA. HAP-TAMRA induced Cp assembly and also bound pre-assembled capsids. Kinetic and spectroscopic studies imply that HAP-binding sites are usually not available but are bound cooperatively. Using cryo-EM, we observed that HAP-TAMRA asymmetrically deformed capsids, creating a heterogeneous array of sharp angles, flat regions, and outright breaks. To achieve high resolution reconstruction (particle symmetry. We deduced that HAP-TAMRA caused quasi-sixfold vertices to become flatter and fivefold more angular. This transition led to asymmetric faceting. That a disordered crosslink could rescue symmetry implies that capsids have tensegrity properties. Capsid distortion and disruption is a new mechanism by which molecules like the HAPs can block HBV infection. PMID:29377794

  14. The H1 linker histones: multifunctional proteins beyond the nucleosomal core particle.

    Science.gov (United States)

    Hergeth, Sonja P; Schneider, Robert

    2015-11-01

    The linker histone H1 family members are a key component of chromatin and bind to the nucleosomal core particle around the DNA entry and exit sites. H1 can stabilize both nucleosome structure and higher-order chromatin architecture. In general, H1 molecules consist of a central globular domain with more flexible tail regions at both their N- and C-terminal ends. The existence of multiple H1 subtypes and a large variety of posttranslational modifications brings about a considerable degree of complexity and makes studying this protein family challenging. Here, we review recent progress in understanding the function of linker histones and their subtypes beyond their role as merely structural chromatin components. We summarize current findings on the role of H1 in heterochromatin formation, transcriptional regulation and embryogenesis with a focus on H1 subtypes and their specific modifications. © 2015 The Authors.

  15. TRF2 Protein Interacts with Core Histones to Stabilize Chromosome Ends.

    Science.gov (United States)

    Konishi, Akimitsu; Izumi, Takashi; Shimizu, Shigeomi

    2016-09-23

    Mammalian chromosome ends are protected by a specialized nucleoprotein complex called telomeres. Both shelterin, a telomere-specific multi-protein complex, and higher order telomeric chromatin structures combine to stabilize the chromosome ends. Here, we showed that TRF2, a component of shelterin, binds to core histones to protect chromosome ends from inappropriate DNA damage response and loss of telomeric DNA. The N-terminal Gly/Arg-rich domain (GAR domain) of TRF2 directly binds to the globular domain of core histones. The conserved arginine residues in the GAR domain of TRF2 are required for this interaction. A TRF2 mutant with these arginine residues substituted by alanine lost the ability to protect telomeres and induced rapid telomere shortening caused by the cleavage of a loop structure of the telomeric chromatin. These findings showed a previously unnoticed interaction between the shelterin complex and nucleosomal histones to stabilize the chromosome ends. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  16. p24 as a predictor of mortality in a cohort of HIV-1-infected adults in rural Africa

    DEFF Research Database (Denmark)

    Erikstrup, C.; Kallestrup, P.; Zinyama-Gutsire, R.B.

    2008-01-01

    BACKGROUND: Implementation of antiretroviral treatment in sub-Saharan Africa requires efficient tools to monitor HIV patients. p24 measurements have been proposed as an alternative to HIV-RNA because of the low cost of reagents and equipment needed. Here, we evaluate p24 as a prognostic marker...

  17. "Hot cores" in proteins: Comparative analysis of the apolar contact area in structures from hyper/thermophilic and mesophilic organisms

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    Bossa Francesco

    2008-02-01

    Full Text Available Abstract Background A wide variety of stabilizing factors have been invoked so far to elucidate the structural basis of protein thermostability. These include, amongst the others, a higher number of ion-pairs interactions and hydrogen bonds, together with a better packing of hydrophobic residues. It has been frequently observed that packing of hydrophobic side chains is improved in hyperthermophilic proteins, when compared to their mesophilic counterparts. In this work, protein crystal structures from hyper/thermophilic organisms and their mesophilic homologs have been compared, in order to quantify the difference of apolar contact area and to assess the role played by the hydrophobic contacts in the stabilization of the protein core, at high temperatures. Results The construction of two datasets was carried out so as to satisfy several restrictive criteria, such as minimum redundancy, resolution and R-value thresholds and lack of any structural defect in the collected structures. This approach allowed to quantify with relatively high precision the apolar contact area between interacting residues, reducing the uncertainty due to the position of atoms in the crystal structures, the redundancy of data and the size of the dataset. To identify the common core regions of these proteins, the study was focused on segments that conserve a similar main chain conformation in the structures analyzed, excluding the intervening regions whose structure differs markedly. The results indicated that hyperthermophilic proteins underwent a significant increase of the hydrophobic contact area contributed by those residues composing the alpha-helices of the structurally conserved regions. Conclusion This study indicates the decreased flexibility of alpha-helices in proteins core as a major factor contributing to the enhanced termostability of a number of hyperthermophilic proteins. This effect, in turn, may be due to an increased number of buried methyl groups in

  18. Mechanisms and Effects on HBV Replication of the Interaction between HBV Core Protein and Cellular Filamin B.

    Science.gov (United States)

    Li, Yilin; Sun, Yishuang; Sun, Fuyun; Hua, Rong; Li, Chenlin; Chen, Lang; Guo, Deyin; Mu, Jingfang

    2018-03-28

    Hepatitis B virus (HBV) infection is one of the major problems that threatens global health. There have been many studies on HBV, but the relationship between HBV and host factors is largely unexplored and more studies are needed to clarify these interactions. Filamin B is an actin-binding protein that acts as a cytoskeleton protein, and it is involved in cell development and several signaling pathways. In this study, we showed that filamin B interacted with HBV core protein, and the interaction promoted HBV replication. The interaction between filamin B and core protein was observed in HEK 293T, Huh7 and HepG2 cell lines by co-immunoprecipitation and co-localization immnofluoresence. Overexpression of filamin B increased the levels of HBV total RNAs and pre-genome RNA (pgRNA), and improved the secretion level of hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg). In contrast, filamin B knockdown inhibited HBV replication, decreased the level of HBV total RNAs and pgRNA, and reduced the secretion level of HBsAg and HBeAg. In addition, we found that filamin B and core protein may interact with each other via four blocks of argentine residues at the C-terminus of core protein. In conclusion, we identify filamin B as a novel host factor that can interact with core protein to promote HBV replication in hepatocytes. Our study provides new insights into the relationship between HBV and host factors and may provide new strategies for the treatment of HBV infection.

  19. Cloning and sequencing of the cDNA encoding a core protein of the paired helical filament of Alzheimer's disease: Identification as the microtubule-associated protein tau

    International Nuclear Information System (INIS)

    Goedert, M.; Wischik, C.M.; Crowther, R.A.; Walker, J.E.; Klug, A.

    1988-01-01

    Screening of cDNA libraries prepared from the frontal cortex of an Alzheimer's disease patient and from fetal human brain has led to isolation of the cDNA for a core protein of the paired helical filament of Alzheimer's disease. The partial amino acid sequence of this core protein was used to design synthetic oligonucleotide probes. The cDNA encodes a protein of 352 amino acids that contains a characteristic amino acid repeat in its carboxyl-terminal half. This protein is highly homologous to the sequence of the mouse microtubule-associated protein tau and thus constitutes the human equivalent of mouse tau. RNA blot analysis indicates the presence of two major transcripts, 6 and 2 kilobases long, with a wide distribution in normal human brain. Tau protein mRNAs were found in normal amounts in the frontal cortex from patients with Alzheimer's disease. The proof that at least part of tau protein forms a component of the paired helical filament core opens the way to understanding the mode of formation of paired helical filaments and thus, ultimately, the pathogenesis of Alzheimer's disease

  20. Structure of a novel shoulder-to-shoulder p24 dimer in complex with the broad-spectrum antibody A10F9 and its implication in capsid assembly.

    Directory of Open Access Journals (Sweden)

    Ying Gu

    Full Text Available Mature HIV-1 viral particles assemble as a fullerene configuration comprising p24 capsid hexamers, pentamers and dimers. In this paper, we report the X-ray crystal structures of the p24 protein from natural HIV-1 strain (BMJ4 in complex with Fab A10F9, which recognizes a conserved epitope in the C-terminal domain of the BMJ4 p24 protein. Our structures reveal a novel shoulder-to-shoulder p24 dimerization mode that is mediated by an S-S bridge at C177. Consistent with these structures, the shoulder-to-shoulder dimer that was obtained from the BMJ4 strain was also observed in p24 proteins from other strains by the introduction of a cysteine residue at position 177. The potential biological significance was further validated by the introduction of a C177A mutation in the BMJ4 strain, which then displays a low infectivity. Our data suggest that this novel shoulder-to-shoulder dimer interface trapped by this unique S-S bridge could represent a physiologically relevant mode of HIV-1 capsid assembly during virus maturation, although Cys residue itself may not be critical for HIV-I replication.

  1. DISTRIBUTION OF GBM HEPARAN-SULFATE PROTEOGLYCAN CORE PROTEIN AND SIDE-CHAINS IN HUMAN GLOMERULAR-DISEASES

    NARCIS (Netherlands)

    VANDENBORN, J; VANDENHEUVEL, LPWJ; BAKKER, MAH; VEERKAMP, JH; ASSMANN, KJM; WEENING, JJ; BERDEN, JHM

    Using monoclonal antibodies (mAbs) recognizing either the core protein or the heparan sulfate (HS) side chain of human GBM heparan sulfate proteoglycan (HSPG), we investigated their glomerular distribution on cryostat sections of human kidney tissues. The study involved 95 biopsies comprising twelve

  2. Aberrant expression of mucin core proteins and o-linked glycans associated with progression of pancreatic cancer

    DEFF Research Database (Denmark)

    Remmers, Neeley; Anderson, Judy M; Linde, Erin M

    2013-01-01

    Mucin expression is a common feature of most adenocarcinomas and features prominently in current attempts to improve diagnosis and therapy for pancreatic cancer and other adenocarcinomas. We investigated the expression of a number of mucin core proteins and associated O-linked glycans expressed i...

  3. Bioinformatic analysis suggests that the Cypovirus 1 major core protein cistron harbours an overlapping gene

    Directory of Open Access Journals (Sweden)

    Atkins John F

    2008-05-01

    Full Text Available Abstract Members of the genus Cypovirus (family Reoviridae are common pathogens of insects. These viruses have linear dsRNA genomes divided into 10–11 segments, which have generally been assumed to be monocistronic. Here, bioinformatic evidence is presented for a short overlapping coding sequence (CDS in the cypovirus genome segment encoding the major core capsid protein VP1, overlapping the 5'-terminal region of the VP1 ORF in the +1 reading frame. In Cypovirus type 1 (CPV-1, a 62-codon AUG-initiated open reading frame (hereafter ORFX is present in all four available segment 1 sequences. The pattern of base variations across the sequence alignment indicates that ORFX is subject to functional constraints at the amino acid level (even when the constraints due to coding in the overlapping VP1 reading frame are taken into account; MLOGD software. In fact the translated ORFX shows greater amino acid conservation than the overlapping region of VP1. The genomic location of ORFX is consistent with translation via leaky scanning. A 62–64 codon AUG-initiated ORF is present in a corresponding location and reading frame in other available cypovirus sequences (2 CPV-14, 1 CPV-15 and an 87-codon ORFX homologue may also be present in Aedes pseudoscutellaris reovirus. The ORFX amino acid sequences are hydrophilic and basic, with between 12 and 16 Arg/Lys residues in each though, at 7.5–10.2 kDa, the putative ORFX product is too small to appear on typical published protein gels.

  4. Identification of protein W, the elusive sixth subunit of the Rhodopseudomonas palustris reaction center-light harvesting 1 core complex.

    Science.gov (United States)

    Jackson, Philip J; Hitchcock, Andrew; Swainsbury, David J K; Qian, Pu; Martin, Elizabeth C; Farmer, David A; Dickman, Mark J; Canniffe, Daniel P; Hunter, C Neil

    2018-02-01

    The X-ray crystal structure of the Rhodopseudomonas (Rps.) palustris reaction center-light harvesting 1 (RC-LH1) core complex revealed the presence of a sixth protein component, variably referred to in the literature as helix W, subunit W or protein W. The position of this protein prevents closure of the LH1 ring, possibly to allow diffusion of ubiquinone/ubiquinol between the RC and the cytochrome bc 1 complex in analogous fashion to the well-studied PufX protein from Rhodobacter sphaeroides. The identity and function of helix W have remained unknown for over 13years; here we use a combination of biochemistry, mass spectrometry, molecular genetics and electron microscopy to identify this protein as RPA4402 in Rps. palustris CGA009. Protein W shares key conserved sequence features with PufX homologs, and although a deletion mutant was able to grow under photosynthetic conditions with no discernible phenotype, we show that a tagged version of protein W pulls down the RC-LH1 complex. Protein W is not encoded in the photosynthesis gene cluster and our data indicate that only approximately 10% of wild-type Rps. palustris core complexes contain this non-essential subunit; functional and evolutionary consequences of this observation are discussed. The ability to purify uniform RC-LH1 and RC-LH1-protein W preparations will also be beneficial for future structural studies of these bacterial core complexes. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  5. Human Adenovirus Infection Causes Cellular E3 Ubiquitin Ligase MKRN1 Degradation Involving the Viral Core Protein pVII.

    Science.gov (United States)

    Inturi, Raviteja; Mun, Kwangchol; Singethan, Katrin; Schreiner, Sabrina; Punga, Tanel

    2018-02-01

    Human adenoviruses (HAdVs) are common human pathogens encoding a highly abundant histone-like core protein, VII, which is involved in nuclear delivery and protection of viral DNA as well as in sequestering immune danger signals in infected cells. The molecular details of how protein VII acts as a multifunctional protein have remained to a large extent enigmatic. Here we report the identification of several cellular proteins interacting with the precursor pVII protein. We show that the cellular E3 ubiquitin ligase MKRN1 is a novel precursor pVII-interacting protein in HAdV-C5-infected cells. Surprisingly, the endogenous MKRN1 protein underwent proteasomal degradation during the late phase of HAdV-C5 infection in various human cell lines. MKRN1 protein degradation occurred independently of the HAdV E1B55K and E4orf6 proteins. We provide experimental evidence that the precursor pVII protein binding enhances MKRN1 self-ubiquitination, whereas the processed mature VII protein is deficient in this function. Based on these data, we propose that the pVII protein binding promotes MKRN1 self-ubiquitination, followed by proteasomal degradation of the MKRN1 protein, in HAdV-C5-infected cells. In addition, we show that measles virus and vesicular stomatitis virus infections reduce the MKRN1 protein accumulation in the recipient cells. Taken together, our results expand the functional repertoire of the HAdV-C5 precursor pVII protein in lytic virus infection and highlight MKRN1 as a potential common target during different virus infections. IMPORTANCE Human adenoviruses (HAdVs) are common pathogens causing a wide range of diseases. To achieve pathogenicity, HAdVs have to counteract a variety of host cell antiviral defense systems, which would otherwise hamper virus replication. In this study, we show that the HAdV-C5 histone-like core protein pVII binds to and promotes self-ubiquitination of a cellular E3 ubiquitin ligase named MKRN1. This mutual interaction between the pVII and

  6. Two types of nanoparticle-based bio-barcode amplification assays to detect HIV-1 p24 antigen

    Directory of Open Access Journals (Sweden)

    Dong Huahuang

    2012-08-01

    Full Text Available Abstract Background HIV-1 p24 antigen is a major viral component of human immunodeficiency virus type 1 (HIV-1 which can be used to identify persons in the early stage of infection and transmission of HIV-1 from infected mothers to infants. The detection of p24 is usually accomplished by using an enzyme-linked immunosorbent assay (ELISA with low detection sensitivity. Here we report the use of two bio-barcode amplification (BCA assays combined with polymerase chain reaction (PCR and gel electrophoresis to quantify HIV-1 p24 antigen. Method A pair of anti-p24 monoclonal antibodies (mAbs were used in BCA assays to capture HIV-1 p24 antigen in a sandwich format and allowed for the quantitative measurement of captured p24 using PCR and gel electrophoresis. The first 1 G12 mAb was coated on microplate wells or magnetic microparticles (MMPs to capture free p24 antigens. Captured p24 in turn captured 1D4 mAb coated gold nanoparticle probes (GNPs containing double-stranded DNA oligonucleotides. One strand of the oligonucleotides was covalently immobilized whereas the unbound complimentary bio-barcode DNA strand could be released upon heating. The released bio-barcode DNA was amplified by PCR, electrophoresed in agarose gel and quantified. Results The in-house ELISA assay was found to quantify p24 antigen with a limit of detection (LOD of 1,000 pg/ml and a linear range between 3,000 and 100,000 pg/ml. In contrast, the BCA-based microplate method yielded an LOD of 1 pg/ml and a linear detection range from 1 to 10,000 pg/ml. The BCA-based MMP method yielded an LOD of 0.1 pg/ml and a linear detection range from 0.1 to 1,000 pg/ml. Conclusions When combined with PCR and simple gel electrophoresis, BCA-based microplate and MMPs assays can be used to quantify HIV-1 p24 antigen. These methods are 3–4 orders of magnitude more sensitive than our in-house ELISA-based assay and may provide a useful approach to detect p24 in patients newly infected

  7. Nonstructural protein 5A is incorporated into hepatitis C virus low-density particle through interaction with core protein and microtubules during intracellular transport.

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    Chao-Kuen Lai

    Full Text Available Nonstructural protein 5A (NS5A of hepatitis C virus (HCV serves dual functions in viral RNA replication and virus assembly. Here, we demonstrate that HCV replication complex along with NS5A and Core protein was transported to the lipid droplet (LD through microtubules, and NS5A-Core complexes were then transported from LD through early-to-late endosomes to the plasma membrane via microtubules. Further studies by cofractionation analysis and immunoelectron microscopy of the released particles showed that NS5A-Core complexes, but not NS4B, were present in the low-density fractions, but not in the high-density fractions, of the HCV RNA-containing virions and associated with the internal virion core. Furthermore, exosomal markers CD63 and CD81 were also detected in the low-density fractions, but not in the high-density fractions. Overall, our results suggest that HCV NS5A is associated with the core of the low-density virus particles which exit the cell through a preexisting endosome/exosome pathway and may contribute to HCV natural infection.

  8. Rearrangement of a polar core provides a conserved mechanism for constitutive activation of class B G protein-coupled receptors

    Science.gov (United States)

    Yin, Yanting; de Waal, Parker W.; He, Yuanzheng; Zhao, Li-Hua; Yang, Dehua; Cai, Xiaoqing; Jiang, Yi; Melcher, Karsten; Wang, Ming-Wei; Xu, H. Eric

    2017-01-01

    The glucagon receptor (GCGR) belongs to the secretin-like (class B) family of G protein-coupled receptors (GPCRs) and is activated by the peptide hormone glucagon. The structures of an activated class B GPCR have remained unsolved, preventing a mechanistic understanding of how these receptors are activated. Using a combination of structural modeling and mutagenesis studies, we present here two modes of ligand-independent activation of GCGR. First, we identified a GCGR-specific hydrophobic lock comprising Met-338 and Phe-345 within the IC3 loop and transmembrane helix 6 (TM6) and found that this lock stabilizes the TM6 helix in the inactive conformation. Disruption of this hydrophobic lock led to constitutive G protein and arrestin signaling. Second, we discovered a polar core comprising conserved residues in TM2, TM3, TM6, and TM7, and mutations that disrupt this polar core led to constitutive GCGR activity. On the basis of these results, we propose a mechanistic model of GCGR activation in which TM6 is held in an inactive conformation by the conserved polar core and the hydrophobic lock. Mutations that disrupt these inhibitory elements allow TM6 to swing outward to adopt an active TM6 conformation similar to that of the canonical β2-adrenergic receptor complexed with G protein and to that of rhodopsin complexed with arrestin. Importantly, mutations in the corresponding polar core of several other members of class B GPCRs, including PTH1R, PAC1R, VIP1R, and CRFR1, also induce constitutive G protein signaling, suggesting that the rearrangement of the polar core is a conserved mechanism for class B GPCR activation. PMID:28356352

  9. Rearrangement of a polar core provides a conserved mechanism for constitutive activation of class B G protein-coupled receptors.

    Science.gov (United States)

    Yin, Yanting; de Waal, Parker W; He, Yuanzheng; Zhao, Li-Hua; Yang, Dehua; Cai, Xiaoqing; Jiang, Yi; Melcher, Karsten; Wang, Ming-Wei; Xu, H Eric

    2017-06-16

    The glucagon receptor (GCGR) belongs to the secretin-like (class B) family of G protein-coupled receptors (GPCRs) and is activated by the peptide hormone glucagon. The structures of an activated class B GPCR have remained unsolved, preventing a mechanistic understanding of how these receptors are activated. Using a combination of structural modeling and mutagenesis studies, we present here two modes of ligand-independent activation of GCGR. First, we identified a GCGR-specific hydrophobic lock comprising Met-338 and Phe-345 within the IC3 loop and transmembrane helix 6 (TM6) and found that this lock stabilizes the TM6 helix in the inactive conformation. Disruption of this hydrophobic lock led to constitutive G protein and arrestin signaling. Second, we discovered a polar core comprising conserved residues in TM2, TM3, TM6, and TM7, and mutations that disrupt this polar core led to constitutive GCGR activity. On the basis of these results, we propose a mechanistic model of GCGR activation in which TM6 is held in an inactive conformation by the conserved polar core and the hydrophobic lock. Mutations that disrupt these inhibitory elements allow TM6 to swing outward to adopt an active TM6 conformation similar to that of the canonical β 2 -adrenergic receptor complexed with G protein and to that of rhodopsin complexed with arrestin. Importantly, mutations in the corresponding polar core of several other members of class B GPCRs, including PTH1R, PAC1R, VIP1R, and CRFR1, also induce constitutive G protein signaling, suggesting that the rearrangement of the polar core is a conserved mechanism for class B GPCR activation. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  10. Suitability of magnetic single- and multi-core nanoparticles to detect protein binding with dynamic magnetic measurement techniques

    International Nuclear Information System (INIS)

    Remmer, Hilke; Dieckhoff, Jan; Schilling, Meinhard; Ludwig, Frank

    2015-01-01

    We investigated the binding of biotinylated proteins to various streptavidin functionalized magnetic nanoparticles with different dynamic magnetic measurement techniques to examine their potential for homogeneous bioassays. As particle systems, single-core nanoparticles with a nominal core diameter of 30 nm as well as multi-core nanoparticles with hydrodynamic sizes varying between nominally 60 nm and 100 nm were chosen. As experimental techniques, fluxgate magnetorelaxometry (MRX), complex ac susceptibility (ACS) and measurements of the phase lag between rotating field and sample magnetization are applied. MRX measurements are only suited for the detection of small analytes if the multivalency of functionalized nanoparticles and analytes causes cross-linking, thus forming larger aggregates. ACS measurements showed for all nanoparticle systems a shift of the imaginary part's maximum towards small frequencies. In rotating field measurements only the single-core nanoparticle systems with dominating Brownian mechanism exhibit an increase of the phase lag upon binding in the investigated frequency range. The coexistence of Brownian and Néel relaxation processes can cause a more complex phase lag change behavior, as demonstrated for multi-core nanoparticle systems. - Highlights: • Cealization of homogeneous magnetic bioassays using different magnetic techniques. • Comparison of single- and multi-core nanoparticle systems. • ac Susceptibility favorable for detection of small analytes. • Magnetorelaxometry favorable for detection of large analytes or cross-linking assays

  11. Decorin core protein (decoron) shape complements collagen fibril surface structure and mediates its binding.

    Science.gov (United States)

    Orgel, Joseph P R O; Eid, Aya; Antipova, Olga; Bella, Jordi; Scott, John E

    2009-09-15

    Decorin is the archetypal small leucine rich repeat proteoglycan of the vertebrate extracellular matrix (ECM). With its glycosaminoglycuronan chain, it is responsible for stabilizing inter-fibrillar organization. Type I collagen is the predominant member of the fibrillar collagen family, fulfilling both organizational and structural roles in animal ECMs. In this study, interactions between decoron (the decorin core protein) and binding sites in the d and e(1) bands of the type I collagen fibril were investigated through molecular modeling of their respective X-ray diffraction structures. Previously, it was proposed that a model-based, highly curved concave decoron interacts with a single collagen molecule, which would form extensive van der Waals contacts and give rise to strong non-specific binding. However, the large well-ordered aggregate that is the collagen fibril places significant restraints on modes of ligand binding and necessitates multi-collagen molecular contacts. We present here a relatively high-resolution model of the decoron-fibril collagen complex. We find that the respective crystal structures complement each other well, although it is the monomeric form of decoron that shows the most appropriate shape complementarity with the fibril surface and favorable calculated energies of interaction. One molecule of decoron interacts with four to six collagen molecules, and the binding specificity relies on a large number of hydrogen bonds and electrostatic interactions, primarily with the collagen motifs KXGDRGE and AKGDRGE (d and e(1) bands). This work helps us to understand collagen-decorin interactions and the molecular architecture of the fibrillar ECM in health and disease.

  12. Decorin core protein (decoron shape complements collagen fibril surface structure and mediates its binding.

    Directory of Open Access Journals (Sweden)

    Joseph P R O Orgel

    2009-09-01

    Full Text Available Decorin is the archetypal small leucine rich repeat proteoglycan of the vertebrate extracellular matrix (ECM. With its glycosaminoglycuronan chain, it is responsible for stabilizing inter-fibrillar organization. Type I collagen is the predominant member of the fibrillar collagen family, fulfilling both organizational and structural roles in animal ECMs. In this study, interactions between decoron (the decorin core protein and binding sites in the d and e(1 bands of the type I collagen fibril were investigated through molecular modeling of their respective X-ray diffraction structures. Previously, it was proposed that a model-based, highly curved concave decoron interacts with a single collagen molecule, which would form extensive van der Waals contacts and give rise to strong non-specific binding. However, the large well-ordered aggregate that is the collagen fibril places significant restraints on modes of ligand binding and necessitates multi-collagen molecular contacts. We present here a relatively high-resolution model of the decoron-fibril collagen complex. We find that the respective crystal structures complement each other well, although it is the monomeric form of decoron that shows the most appropriate shape complementarity with the fibril surface and favorable calculated energies of interaction. One molecule of decoron interacts with four to six collagen molecules, and the binding specificity relies on a large number of hydrogen bonds and electrostatic interactions, primarily with the collagen motifs KXGDRGE and AKGDRGE (d and e(1 bands. This work helps us to understand collagen-decorin interactions and the molecular architecture of the fibrillar ECM in health and disease.

  13. Hepatitis C virus core protein expression leads to biphasic regulation of the p21 cdk inhibitor and modulation of hepatocyte cell cycle

    International Nuclear Information System (INIS)

    Nguyen, Hau; Mudryj, Maria; Guadalupe, Moraima; Dandekar, Satya

    2003-01-01

    Hepatitis C virus (HCV) Core protein is implicated in viral pathogenesis by the modulation of hepatocyte gene expression and function. To determine the effect of Core protein on the cell-cycle control of hepatocytes, a HepG2 cell line containing a Flag-tagged Core under the control of an inducible promoter was generated. Initial Core protein expression included the presence of unprocessed (191 aa) and processed (173 aa) forms of the Core proteins with the processed form becoming dominant later. Expression of the 191 aa form of Core protein corresponded to an increase in the expression of the p21, a decrease in cdk2-dependent kinase activity, and a decrease in the percentage of cells in S-phase along with an accumulation of cells in the G 0 /G 1 phase of the cell cycle. As the processed form accumulated, the p21 levels started to decline, suggesting that Core protein regulates p21 expression in a biphasic manner. These findings implicate Core protein in potentially modulating hepatocyte cell cycle differentially in the early stages of infection through biphasic regulation of p21 cdk kinase inhibitor

  14. Conformational Changes in the Hepatitis B Virus Core Protein Are Consistent with a Role for Allostery in Virus Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Packianathan, Charles; Katen, Sarah P.; Dann, III, Charles E.; Zlotnick, Adam (Indiana)

    2010-01-12

    In infected cells, virus components must be organized at the right place and time to ensure assembly of infectious virions. From a different perspective, assembly must be prevented until all components are available. Hypothetically, this can be achieved by allosterically controlling assembly. Consistent with this hypothesis, here we show that the structure of the hepatitis B virus (HBV) core protein dimer, which can spontaneously self-assemble, is incompatible with capsid assembly. Systematic differences between core protein dimer and capsid conformations demonstrate linkage between the intradimer interface and interdimer contact surface. These structures also provide explanations for the capsid-dimer selectivity of some antibodies and the activities of assembly effectors. Solution studies suggest that the assembly-inactive state is more accurately an ensemble of conformations. Simulations show that allostery supports controlled assembly and results in capsids that are resistant to dissociation. We propose that allostery, as demonstrated in HBV, is common to most self-assembling viruses.

  15. Multifunctional Fe3O4/Au core/satellite nanocubes: an efficient chemical synthesis, characterization and functionalization of streptavidin protein.

    Science.gov (United States)

    Abbas, Mohamed; RamuluTorati, Sri; Kim, CheolGi

    2017-02-14

    A novel and efficient chemical approach for the synthesis of Fe 3 O 4 /Au core/satellite nanocubes is reported. In a one-pot reaction, metallic Au nanodots were successfully deposited on the polyvinylpyrrolidone (PVP) functionalized Fe 3 O 4 nanocube surface for the fabrication of a core/satellite structure (Fe 3 O 4 /Au) by the reduction of HAuCl 4 using ammonia. Transmission electron microscopy and energy dispersive spectroscopy mapping revealed that small Au nanodots of about 2 nm average size decorated the surface of Fe 3 O 4 nanocubes. X-ray diffraction data was used to confirm the formation of both the phases of a cubic inverse spinel structure for Fe 3 O 4 and a bcc structure for Au in the core/satellite structure of Fe 3 O 4 /Au nanocubes. The magnetic properties of the seed Fe 3 O 4 nanocubes and Fe 3 O 4 /Au core/satellite nanocubes were measured by using a superconducting quantum interference device at 300 K. For biological application purposes, the as-synthesized Fe 3 O 4 /Au core/satellite nanocubes were functionalized by cysteamine followed by successful immobilization of streptavidin protein as confirmed through the fluorescence confocal microscopy images.

  16. The hepatitis C virus Core protein is a potent nucleic acid chaperone that directs dimerization of the viral (+) strand RNA in vitro.

    Science.gov (United States)

    Cristofari, Gaël; Ivanyi-Nagy, Roland; Gabus, Caroline; Boulant, Steeve; Lavergne, Jean-Pierre; Penin, François; Darlix, Jean-Luc

    2004-01-01

    The hepatitis C virus (HCV) is an important human pathogen causing chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. HCV is an enveloped virus with a positive-sense, single-stranded RNA genome encoding a single polyprotein that is processed to generate viral proteins. Several hundred molecules of the structural Core protein are thought to coat the genome in the viral particle, as do nucleocapsid (NC) protein molecules in Retroviruses, another class of enveloped viruses containing a positive-sense RNA genome. Retroviral NC proteins also possess nucleic acid chaperone properties that play critical roles in the structural remodelling of the genome during retrovirus replication. This analogy between HCV Core and retroviral NC proteins prompted us to investigate the putative nucleic acid chaperoning properties of the HCV Core protein. Here we report that Core protein chaperones the annealing of complementary DNA and RNA sequences and the formation of the most stable duplex by strand exchange. These results show that the HCV Core is a nucleic acid chaperone similar to retroviral NC proteins. We also find that the Core protein directs dimerization of HCV (+) RNA 3' untranslated region which is promoted by a conserved palindromic sequence possibly involved at several stages of virus replication.

  17. High prevalence of HIV p24 antigen among HIV antibody negative prospective blood donors in Ile-Ife, Nigeria.

    Science.gov (United States)

    Japhet, Margaret Oluwatoyin; Adewumi, Moses Olubusuyi; Adesina, Olufisayo Adeyemi; Donbraye, Emmanuel

    2016-01-01

    Blood transfusion service centers in Nigeria screen donated blood for markers of HIV infection using antibody- (Ab) based rapid test and in some centers, positives are re-tested using Ab-based ELISA. Paucity of data exists on p24 antigen prevalence among HIV Ab-negative donors in Nigeria. This study aims at detecting HIV p24 antigen among prospective blood donors in Osun State, Nigeria. Prospective blood donors negative for HIV antibodies using Determine test kit were re-tested using BIORAD GENSCREEN Ultra Ag-Ab ELISA kit, a fourth-generation ELISA kit that detects HIV antibodies/p24 antigen. Of the 169 HIV Ab-negative prospective donors, 10 (5.9%) were positive for HIV p24 antigen and 70% (7/10) of them were in the age range 18-30 years. Results of this study show that blood transfusion is still one of the major routes of HIV transmission in Nigeria and a higher proportion is among youth. Inclusion of p24 antigen testing into the blood donor screening will help reduce transfusion associated HIV in Nigeria if Nucleic Acid Testing (NAT) of all blood donor samples is not affordable; also, HIV enlightenment programs tailored toward youth may help reduce this rate among donors since more young people donate blood in low/middle-income countries than in high-income countries.

  18. Core Data of Yeast Interacting Proteins Database (Original Version) - Yeast Interacting Proteins Database | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available y are in the reverse direction. *1 A comprehensive two-hybrid analysis to explore the yeast protein interact...s. 2000 Jan 1;28(1):73-6. *2 The yeast proteome database (YPD) and Caenorhabditis elegans proteome database (WormPD): comprehensive...000 Jan 1;28(1):73-6. *3 A comprehensive analysis of protein-protein interactions in Saccharomyces cerevisia

  19. Impairment of interferon regulatory factor-3 activation by hepatitis C virus core protein basic amino acid region 1.

    Science.gov (United States)

    Inoue, Kazuaki; Tsukiyama-Kohara, Kyoko; Matsuda, Chiho; Yoneyama, Mitsutoshi; Fujita, Takashi; Kuge, Shusuke; Yoshiba, Makoto; Kohara, Michinori

    2012-11-30

    Interferon regulatory factor-3 (IRF-3), a key transcriptional factor in the type I interferon system, is frequently impaired by hepatitis C virus (HCV), in order to establish persistent infection. However, the exact mechanism by which the virus establishes persistent infection has not been fully understood yet. The present study aimed to investigate the effects of various HCV proteins on IRF-3 activation, and elucidate the underlying mechanisms. To achieve this, full-length HCV and HCV subgenomic constructs corresponding to structural and each of the nonstructural proteins were transiently transfected into HepG2 cells. IFN-β induction, plaque formation, and IRF-3 dimerization were elicited by Newcastle disease virus (NDV) infection. The expressions of IRF-3 homodimer and its monomer, Ser386-phosphorylated IRF-3, and HCV core protein were detected by immunofluorescence and western blotting. IFN-β mRNA expression was quantified by real-time PCR (RT-PCR), and IRF-3 activity was measured by the levels of IRF-3 dimerization and phosphorylation, induced by NDV infection or polyriboinosinic:polyribocytidylic acid [poly(I:C)]. Switching of the expression of the complete HCV genome as well as the core proteins, E1, E2, and NS2, suppressed IFN-β mRNA levels and IRF-3 dimerization, induced by NDV infection. Our study revealed a crucial region of the HCV core protein, basic amino acid region 1 (BR1), to inhibit IRF-3 dimerization as well as its phosphorylation induced by NDV infection and poly (I:C), thus interfering with IRF-3 activation. Therefore, our study suggests that rescue of the IRF-3 pathway impairment may be an effective treatment for HCV infection. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. Rotavirus NSP2 interferes with the core lattice protein VP2 in initiation of minus-strand synthesis

    International Nuclear Information System (INIS)

    Vende, Patrice; Tortorici, M. Alejandra; Taraporewala, Zenobia F.; Patton, John T.

    2003-01-01

    The rotavirus nonstructural protein NSP2 self-assembles into stable octameric structures that possess nonspecific affinity for single-stranded (ss)RNA and RNA-RNA helix-destabilizing and NTPase activities. Furthermore, NSP2 is a component of replication intermediates with replicase activity and plays a critical role in the packaging and replication of the segmented dsRNA genome of rotavirus. To better understand the function of the protein in genome replication, we examined the effect that purified recombinant NSP2 had on the synthesis of dsRNA by the open core replication system. The results showed that NSP2 inhibited the synthesis of dsRNA from viral mRNA in vitro, in a concentration-dependent manner. The inhibition was overcome by adding increasing amounts of viral mRNA or nonviral ssRNA to the system, indicating that the inhibition was mediated by the nonspecific RNA-binding activity of NSP2. Further analysis revealed that NSP2 interfered with the ability of the open core proteins, GTP, and viral mRNA to form the initiation complex for (-) strand synthesis. Additional experiments indicated that NSP2 did not perturb recognition of viral mRNA by the viral RNA polymerase VP1, but rather interfered with the function of VP2, a protein that is essential for (-) strand initiation and dsRNA synthesis and that forms the T = 1 lattice of the virion core. In contrast to initiation, NSP2 did not inhibit (-) strand elongation. Collectively, the findings provide evidence that the temporal order of interaction of RNA-binding proteins with viral mRNA is a crucial factor impacting the formation of replication intermediates

  1. Protein-energy malnutrition induces an aberrant acute-phase response and modifies the circadian rhythm of core temperature.

    Science.gov (United States)

    Smith, Shari E; Ramos, Rafaela Andrade; Refinetti, Roberto; Farthing, Jonathan P; Paterson, Phyllis G

    2013-08-01

    Protein-energy malnutrition (PEM), present in 12%-19% of stroke patients upon hospital admission, appears to be a detrimental comorbidity factor that impairs functional outcome, but the mechanisms are not fully elucidated. Because ischemic brain injury is highly temperature-sensitive, the objectives of this study were to investigate whether PEM causes sustained changes in temperature that are associated with an inflammatory response. Activity levels were recorded as a possible explanation for the immediate elevation in temperature upon introduction to a low protein diet. Male, Sprague-Dawley rats (7 weeks old) were fed a control diet (18% protein) or a low protein diet (PEM, 2% protein) for either 7 or 28 days. Continuous core temperature recordings from bioelectrical sensor transmitters demonstrated a rapid increase in temperature amplitude, sustained over 28 days, in response to a low protein diet. Daily mean temperature rose transiently by day 2 (p = 0.01), falling to normal by day 4 (p = 0.08), after which mean temperature continually declined as malnutrition progressed. There were no alterations in activity mean (p = 0.3) or amplitude (p = 0.2) that were associated with the early rise in mean temperature. Increased serum alpha-2-macroglobulin (p protein diet had no effect on the signaling pathway of the pro-inflammatory transcription factor, NFκB, in the hippocampus. In conclusion, PEM induces an aberrant and sustained acute-phase response coupled with long-lasting effects on body temperature.

  2. Expression of Hepatitis C Virus Core and E2 antigenic recombinant proteins and their use for development of diagnostic assays.

    Science.gov (United States)

    Ali, Amjad; Nisar, Muhammad; Idrees, Muhammad; Rafique, Shazia; Iqbal, Muhammad

    2015-05-01

    Early diagnosis of HCV infection is based on detection of antibodies against HCV proteins using recombinant viral antigens. The present study was designed to select, clone and express the antigenic regions of Core and E2 genes from local HCV-3a genotype and to utilize the antigenic recombinant proteins (Core & E2) to develop highly sensitive, specific and economical diagnostic assays for detection of HCV infection. The antigenic sites were determined within Core and E2 genes and were then cloned in pET-28a expression vector. The right orientation of the desired inserted fragments of Core and E2 were confirmed via sequencing prior to expression and were then transformed in BL21 (DE3) pLysS strains of E. coli and induced with 0.5mM Isopropyl-b-D-thiogalactopyranoside (IPTG) for the production of antigenic recombinant proteins. The produced truncated antigens were then purified by Nickel affinity chromatography and were confirmed by western blotting, immunoblotting and enzyme-linked immunosorbent assay (ELISA). The expressed Core and E2 recombinant antigens were used to develop immunoblotting assay for the detection of anti-HCV antibodies in sera. With immunoblotting, a total of 93-HCV infected sera and 35-HCV negative individuals were tested for the presence of anti-HCV antibodies to the Core and E2 antigens. Recombinant antigen showed 100% reactivity against HCV infected sera, with no cross reactivity against HCV-negative sera. The immunoblot assay mixture of recombinant antigens (Core+E2) showed a strong reaction intensity in the test area (TA) as compared to the individual truncated Core and E2 recombinant antigens. In the in-house ELISA assay, mixed Core and E2 recombinant antigens showed 100% reactivity against a standardized panel of 150-HCV-positive sera and non reactivity against a standardized panel of 150 HCV-negative sera while also being non reactive to sera positive for other viral infections. The antigenic recombinant antigens also were tested for the

  3. [Effects of sintered bone modified with surface mineralization/P24 peptide composite biomaterial on the adhesion, proliferation and osteodifferentiation of MC3T3-E1 cells].

    Science.gov (United States)

    Li, Jingfeng; Zheng, Qixin; Guo, Xiaodong; Chen, Liaobin

    2014-10-01

    In the present research, the effects of sintered bone modified with surface mineralization/P24 peptide composite biomaterials on the adhesion, proliferation and osteodifferentiation of MC3T3-E1 cells were investigated. The experiments were divided into three groups due to biomaterials used: Group A (composite materials of sintered bone modified with surface mineralization and P24, a peptide of bone morphogenetic protein-2); Group B (sintered bone modified with surface mineralization) and Group C (sintered bone only). The three groups were observed by scanning electron microscopy (SEM) before the experiments, respectively. Then MC3T3-E1 cells were cultured on the surfaces of the three kinds of material, respectively. The cell adhesion rate was assessed by precipitation method. The proliferative ability of MC3T3-E1 cells were measured with MTT assay. And the ALP staining and measurement of alkaline phosphatase (ALP) activity were performed to assess the differentiation of cells into osteoblasts. The SEM results showed that the materials in the three groups retained the natural pore structure and the pore sizes were in the range between 200-850 μm. The adhesive ratio measurements and MTT assay suggested that adhesion and proliferation of MC3T3-E1 cells in Group A were much higher than those in Group B and Group C (P bone modified with surface mineralization/P24 composite material was confirmed to improve the adhesion rate and proliferation and osteodifferentiation of MC3T3-E1 cells, and maintained their morphology.

  4. The Replacement of 10 Non-Conserved Residues in the Core Protein of JFH-1 Hepatitis C Virus Improves Its Assembly and Secretion.

    Directory of Open Access Journals (Sweden)

    Loïc Etienne

    Full Text Available Hepatitis C virus (HCV assembly is still poorly understood. It is thought that trafficking of the HCV core protein to the lipid droplet (LD surface is essential for its multimerization and association with newly synthesized HCV RNA to form the viral nucleocapsid. We carried out a mapping analysis of several complete HCV genomes of all genotypes, and found that the genotype 2 JFH-1 core protein contained 10 residues different from those of other genotypes. The replacement of these 10 residues of the JFH-1 strain sequence with the most conserved residues deduced from sequence alignments greatly increased virus production. Confocal microscopy of the modified JFH-1 strain in cell culture showed that the mutated JFH-1 core protein, C10M, was present mostly at the endoplasmic reticulum (ER membrane, but not at the surface of the LDs, even though its trafficking to these organelles was possible. The non-structural 5A protein of HCV was also redirected to ER membranes and colocalized with the C10M core protein. Using a Semliki forest virus vector to overproduce core protein, we demonstrated that the C10M core protein was able to form HCV-like particles, unlike the native JFH-1 core protein. Thus, the substitution of a few selected residues in the JFH-1 core protein modified the subcellular distribution and assembly properties of the protein. These findings suggest that the early steps of HCV assembly occur at the ER membrane rather than at the LD surface. The C10M-JFH-1 strain will be a valuable tool for further studies of HCV morphogenesis.

  5. Fluorescent protein-tagged Vpr dissociates from HIV-1 core after viral fusion and rapidly enters the cell nucleus.

    Science.gov (United States)

    Desai, Tanay M; Marin, Mariana; Sood, Chetan; Shi, Jiong; Nawaz, Fatima; Aiken, Christopher; Melikyan, Gregory B

    2015-10-29

    HIV-1 Vpr is recruited into virions during assembly and appears to remain associated with the viral core after the reverse transcription and uncoating steps of entry. This feature has prompted the use of fluorescently labeled Vpr to visualize viral particles and to follow trafficking of post-fusion HIV-1 cores in the cytoplasm. Here, we tracked single pseudovirus entry and fusion and observed that fluorescently tagged Vpr gradually dissociates from post-fusion viral cores over the course of several minutes and accumulates in the nucleus. Kinetics measurements showed that fluorescent Vpr released from the cores very rapidly entered the cell nucleus. More than 10,000 Vpr molecules can be delivered into the cell nucleus within 45 min of infection by HIV-1 particles pseudotyped with the avian sarcoma and leukosis virus envelope glycoprotein. The fraction of Vpr from cell-bound viruses that accumulated in the nucleus was proportional to the extent of virus-cell fusion and was fully blocked by viral fusion inhibitors. Entry of virus-derived Vpr into the nucleus occurred independently of envelope glycoproteins or target cells. Fluorescence correlation spectroscopy revealed two forms of nuclear Vpr-monomers and very large complexes, likely involving host factors. The kinetics of viral Vpr entering the nucleus after fusion was not affected by point mutations in the capsid protein that alter the stability of the viral core. The independence of Vpr shedding of capsid stability and its relatively rapid dissociation from post-fusion cores suggest that this process may precede capsid uncoating, which appears to occur on a slower time scale. Our results thus demonstrate that a bulk of fluorescently labeled Vpr incorporated into HIV-1 particles is released shortly after fusion. Future studies will address the question whether the quick and efficient nuclear delivery of Vpr derived from incoming viruses can regulate subsequent steps of HIV-1 infection.

  6. Purification, crystallization and preliminary X-ray diffraction study of human ribosomal protein L10 core domain

    International Nuclear Information System (INIS)

    Nishimura, Mitsuhiro; Kaminishi, Tatsuya; Kawazoe, Masahito; Shirouzu, Mikako; Takemoto, Chie; Yokoyama, Shigeyuki; Tanaka, Akiko; Sugano, Sumio; Yoshida, Takuya; Ohkubo, Tadayasu; Kobayashi, Yuji

    2007-01-01

    A truncated variant of human ribosomal protien L10 was prepared and crystallized. Diffraction data were collected to 2.5 Å resolution. Eukaryotic ribosomal protein L10 is an essential component of the large ribosomal subunit, which organizes the architecture of the aminoacyl-tRNA binding site. The human L10 protein is also called the QM protein and consists of 214 amino-acid residues. For crystallization, the L10 core domain (L10CD, Phe34–Glu182) was recombinantly expressed in Escherichia coli and purified to homogeneity. A hexagonal crystal of L10CD was obtained by the sitting-drop vapour-diffusion method. The L10CD crystal diffracted to 2.5 Å resolution and belongs to space group P3 1 21 or P3 2 21

  7. Global Structural Flexibility of Metalloproteins Regulates Reactivity of Transition Metal Ion in the Protein Core: An Experimental Study Using Thiol-subtilisin as a Model Protein.

    Science.gov (United States)

    Matsuo, Takashi; Kono, Takamasa; Shobu, Isamu; Ishida, Masaya; Gonda, Katsuya; Hirota, Shun

    2018-02-21

    The functions of metal-containing proteins (metalloproteins) are determined by the reactivities of transition metal ions at their active sites. Because protein macromolecular structures have several molecular degrees of freedom, global structural flexibility may also regulate the properties of metalloproteins. However, the influence of this factor has not been fully delineated in mechanistic studies of metalloproteins. Accordingly, we have investigated the relationship between global protein flexibility and the characteristics of a transition metal ion in the protein core using thiol-subtilisin (tSTL) with a Cys-coordinated Cu 2+ ion as a model system. Although tSTL has two Ca 2+ -binding sites, the Ca 2+ -binding status hardly affects its secondary structure. Nevertheless, guanidinium-induced denaturation and amide H/D exchange indicated the increase in the structural flexibility of tSTL by the removal of bound Ca 2+ ions. Electron paramagnetic resonance and absorption spectral changes have revealed that the protein flexibility determines the characteristics of a Cu 2+ ion in tSTL. Therefore, global protein flexibility should be recognized as an important factor that regulates the properties of metalloproteins. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. In vitro studies on heme oxygenase-1 and P24 antigen HIV-1 level ...

    African Journals Online (AJOL)

    Background: Heme oxygenase-1 (HO-1) is a protein secreted by immune cells as a part of immune response mechanism.HO-1 can be induced by variety agents that causingoxidative stress, such as exposure to 100% oxygenat2,4 ATA pressure.It plays a vital role in maintaining cellular homeostasis.This study was ...

  9. Alcohol Induced Hepatic Degeneration in a Hepatitis C Virus Core Protein Transgenic Mouse Model

    Directory of Open Access Journals (Sweden)

    Dong-Hyung Noh

    2014-03-01

    Full Text Available Hepatitis C virus (HCV has become a major public health issue. It is prevalent in most countries. HCV infection frequently begins without clinical symptoms, before progressing to persistent viremia, chronic hepatitis, cirrhosis and hepatocellular carcinoma (HCC in the majority of patients (70% to 80%. Alcohol is an independent cofactor that accelerates the development of HCC in chronic hepatitis C patients. The purpose of the current study was to evaluate ethanol-induced hepatic changes in HCV core-Tg mice and mutant core Tg mice. Wild type (NTG, core wild-Tg mice (TG-K, mutant core 116-Tg mice (TG-116 and mutant core 99-Tg mice (TG-99 were used in this investigation. All groups were given drinking water with 10% ethanol and 5% sucrose for 13 weeks. To observe liver morphological changes, we performed histopathological and immunohistochemical examinations. Histopathologically, NTG, TG-K and TG-116 mice showed moderate centrilobular necrosis, while severe centrilobular necrosis and hepatocyte dissociation were observed in TG-99 mice with increasing lymphocyte infiltration and piecemeal necrosis. In all groups, a small amount of collagen fiber was found, principally in portal areas. None of the mice were found to have myofibroblasts based on immunohistochemical staining specific for α-SMA. CYP2E1-positive cells were clearly detected in the centrilobular area in all groups. In the TG-99 mice, we also observed cells positive for CK8/18, TGF-β1 and phosphorylated (p-Smad2/3 and p21 around the necrotic hepatocytes in the centrilobular area (p < 0.01. Based on our data, alcohol intake induced piecemeal necrosis and hepatocyte dissociation in the TG-99 mice. These phenomena involved activation of the TGF-β1/p-Smad2/3/p21 signaling pathway in hepatocytes. Data from this study will be useful for elucidating the association between alcohol intake and HCV infection.

  10. Getting to the core of protein pharmaceuticals – comprehensive structure analysis by mass spectrometry

    DEFF Research Database (Denmark)

    Leurs, Ulrike; Mistarz, Ulrik Hvid; Rand, Kasper Dyrberg

    2015-01-01

    . Mass spectrometry has evolved as a powerful tool for the characterization of both primary and higher order structures of protein pharmaceuticals. Furthermore, the chemical and physical stability of protein drugs, as well as their pharmacokinetics are nowadays routinely determined by mass spectrometry...

  11. IN VITRO STUDIES ON HEME OXYGENASE-1 AND P24 ANTIGEN HIV-1 LEVEL AFTERHYPERBARIC OXYGEN TREATMENTOFHIV-1 INFECTED ON PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMCS).

    Science.gov (United States)

    Budiarti, Retno; Kuntaman; Nasronudin; Suryokusumo; Khairunisa, Siti Qamariyah

    2018-01-01

    Heme oxygenase-1 (HO-1) is a protein secreted by immune cells as a part of immune response mechanism.HO-1 can be induced by variety agents that causingoxidative stress, such as exposure to 100% oxygenat2,4 ATA pressure.It plays a vital role in maintaining cellular homeostasis.This study was conducted to identify the effect of hyperbaric oxygen exposure in cultured ofPBMCthat infected by HIV-1. Primary culture of PBMCs were isolated from 16 healthy volunteers and HIV-1 infected MT4 cell line by co-culture. The PBMCs were aliquoted into two wells as control group and treatment group. The 16 samples of HIV-1 infected PBMCwere exposed to oxygen at 2,4 ATA in animal hyperbaric chamber forthree times in 30 minutes periods with 5 minutes spacing period, that called 1 session.The Treatment done on 5 sessions within 5 days. 16 samples of HIV-1 infected PMBCs that have no hyperbaric treatment became control group.The supernatant were measured the HO-1 production by ELISA andmRNA expression of HO-1 by real time PCR and the number ofantigen p24 HIV-1by ELISA. The result showed that there was no increasing of HO-1 at both mRNA level and protein level, there was a decreasing number of antigen p24 HIV-1 at the treatment group. In addition, hyperbaric exposure could not increase the expression of HO-1, more over the viral replication might be reduced by other mechanism. Hyperbaric oxygen could increases cellular adaptive response of PBMCs infected HIV-1 through increased expression of proteins that can inhibit HIV viralreplication.

  12. Charge neutralization as the major factor for the assembly of nucleocapsid-like particles from C-terminal truncated hepatitis C virus core protein

    OpenAIRE

    Theo Luiz Ferraz de Souza; Sheila Maria Barbosa de Lima; Vanessa L. de Azevedo Braga; David S. Peabody; Davis Fernandes Ferreira; M. Lucia Bianconi; Andre Marco de Oliveira Gomes; Jerson Lima Silva; Andréa Cheble de Oliveira

    2016-01-01

    Background Hepatitis C virus (HCV) core protein, in addition to its structural role to form the nucleocapsid assembly, plays a critical role in HCV pathogenesis by interfering in several cellular processes, including microRNA and mRNA homeostasis. The C-terminal truncated HCV core protein (C124) is intrinsically unstructured in solution and is able to interact with unspecific nucleic acids, in the micromolar range, and to assemble into nucleocapsid-like particles (NLPs) in vitro. The specific...

  13. Heparan sulfate proteoglycan from the extracellular matrix of human lung fibroblasts. Isolation, purification, and core protein characterization

    International Nuclear Information System (INIS)

    Heremans, A.; Cassiman, J.J.; Van den Berghe, H.; David, G.

    1988-01-01

    Confluent cultured human lung fibroblasts were labeled with 35SO4(2-). After 48 h of labeling, the pericellular matrix was prepared by Triton X-100 and deoxycholate extraction of the monolayers. Heparan sulfate proteoglycan (HSPG) accounted for nearly 80% of the total matrix [35S]proteoglycans. After solubilization in 6 M guanidinium HCl and cesium chloride density gradient centrifugation, the majority (78%) of these [35S] HSPG equilibrated at an average buoyant density of 1.35 g/ml. This major HSPG fraction was purified by ion-exchange chromatography on Mono Q and by gel filtration on Sepharose CL-4B, and further characterized by gel electrophoresis and immunoblotting. Intact [35S]HSPG eluted with Kav 0.1 from Sepharose CL-4B, whereas the protein-free [35S]heparan sulfate chains, obtained by alkaline borohydride treatment of the proteoglycan fractions, eluted with Kav 0.45 (Mr approximately 72,000). When analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography, core (protein) preparations, obtained by heparitinase digestion of 125I-labeled HSPG fractions, yielded one major labeled band with apparent molecular mass of approximately 300 kDa. Reduction with beta-mercaptoethanol slightly increased the apparent Mr of the labeled band, suggesting a single polypeptide structure and the presence of intrachain disulfide bonds. Immunoadsorption experiments and immunostaining of electrophoretically separated heparitinase-digested core proteins with monoclonal antibodies raised against matrix and cell surface-associated HSPG suggested that the major matrix-associated HSPG of cultured human lung fibroblasts is distinct from the HSPG that are anchored in the membranes of these cells. Binding studies suggested that this matrix HSPG interacts with several matrix components, both through its glycosaminoglycan chains and through its heparitinase-resistant core. (Abstract Truncated)

  14. Enhancement of curcumin water dispersibility and antioxidant activity using core-shell protein-polysaccharide nanoparticles.

    Science.gov (United States)

    Huang, Xiaoxia; Huang, Xulin; Gong, Yushi; Xiao, Hang; McClements, David Julian; Hu, Kun

    2016-09-01

    Curcumin has strong antioxidant activity, but poor water-solubility and chemical stability, which limits its utilization as a nutraceutical in many applications. Previously, we developed a core-shell (zein-pectin) nanoparticle delivery system with high curcumin loading efficiency, high particle yield, and good water dispersibility. However, this system was unstable to aggregation around neutral pH and moderate ionic strengths due to weakening of electrostatic repulsion between nanoparticles. In the current study, we used a combination of alginate (high charge density) and pectin (low charge density) to form the shell around zein nanoparticles. Replacement of 30% of pectin with alginate greatly improved aggregation stability at pH 5 to 7 and at high ionic strengths (2000mM NaCl). Curcumin encapsulated within these core-shell nanoparticles exhibited higher antioxidant and radical scavenging activities than curcumin solubilized in ethanol solutions as determined by Fe (III) reducing power, 1, 1-Diphenyl-2-picrylhydrazyl free radical (DPPH·), and 2, 2'-azinobis-(3-ethylbenzothiazoline)-6-sulfonic acid radical cation (ABTS· + ) scavenging analysis. These core-shell nanoparticles may be useful for incorporating chemically unstable hydrophobic nutraceuticals such as curcumin into functional foods, dietary supplements, and pharmaceuticals. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Analysis of hepatitis C virus core/NS5A protein co-localization using novel cell culture systems expressing core-NS2 and NS5A of genotypes 1-7

    DEFF Research Database (Denmark)

    Galli, Andrea; Scheel, Troels K H; Prentoe, Jannick C

    2013-01-01

    Hepatitis C virus (HCV) is an important human pathogen infecting hepatocytes. With the advent of infectious cell culture systems, the HCV particle assembly and release processes are finally being uncovered. The HCV core and NS5A proteins co-localize on cytoplasmic lipid droplets (c......LDs) or on the endoplasmic reticulum (ER) at different stages of particle assembly. Current knowledge on assembly and release is primarily based on studies in genotype 2a cell culture systems; however, given the high genetic heterogeneity of HCV, variations might exist among genotypes. Here, we developed novel HCV strain...... JFH1-based recombinants expressing core-NS2 and NS5A from genotypes 1-7, and analysed core and NS5A co-localization in infected cells. Huh7.5 cells were transfected with RNA of core-NS2/NS5A recombinants and putative adaptive mutations were analysed by reverse genetics. Adapted core-NS2/NS5A...

  16. Pokemon siRNA Delivery Mediated by RGD-Modified HBV Core Protein Suppressed the Growth of Hepatocellular Carcinoma.

    Science.gov (United States)

    Kong, Jing; Liu, Xiaoping; Jia, Jianbo; Wu, Jinsheng; Wu, Ning; Chen, Jun; Fang, Fang

    2015-10-01

    Hepatocellular carcinoma (HCC) is a deadly human malignant tumor that is among the most common cancers in the world, especially in Asia. Hepatitis B virus (HBV) infection has been well established as a high risk factor for hepatic malignance. Studies have shown that Pokemon is a master oncogene for HCC growth, suggesting it as an ideal therapeutic target. However, efficient delivery system is still lacking for Pokemon targeting treatment. In this study, we used core proteins of HBV, which is modified with RGD peptides, to construct a biomimetic vector for the delivery of Pokemon siRNAs (namely, RGD-HBc-Pokemon siRNA). Quantitative PCR and Western blot assays revealed that RGD-HBc-Pokemon siRNA possessed the highest efficiency of Pokemon suppression in HCC cells. In vitro experiments further indicated that RGD-HBc-Pokemon-siRNA exerted a higher tumor suppressor activity on HCC cell lines, evidenced by reduced proliferation and attenuated invasiveness, than Pokemon-siRNA or RGD-HBc alone. Finally, animal studies demonstrated that RGD-HBc-Pokemon siRNA suppressed the growth of HCC xenografts in mice by a greater extent than Pokemon-siRNA or RGD-HBc alone. Based on the above results, Pokemon siRNA delivery mediated by RGD-modified HBV core protein was shown to be an effective strategy of HCC gene therapy.

  17. Human Cytomegalovirus Nuclear Capsids Associate with the Core Nuclear Egress Complex and the Viral Protein Kinase pUL97.

    Science.gov (United States)

    Milbradt, Jens; Sonntag, Eric; Wagner, Sabrina; Strojan, Hanife; Wangen, Christina; Lenac Rovis, Tihana; Lisnic, Berislav; Jonjic, Stipan; Sticht, Heinrich; Britt, William J; Schlötzer-Schrehardt, Ursula; Marschall, Manfred

    2018-01-13

    The nuclear phase of herpesvirus replication is regulated through the formation of regulatory multi-component protein complexes. Viral genomic replication is followed by nuclear capsid assembly, DNA encapsidation and nuclear egress. The latter has been studied intensely pointing to the formation of a viral core nuclear egress complex (NEC) that recruits a multimeric assembly of viral and cellular factors for the reorganization of the nuclear envelope. To date, the mechanism of the association of human cytomegalovirus (HCMV) capsids with the NEC, which in turn initiates the specific steps of nuclear capsid budding, remains undefined. Here, we provide electron microscopy-based data demonstrating the association of both nuclear capsids and NEC proteins at nuclear lamina budding sites. Specifically, immunogold labelling of the core NEC constituent pUL53 and NEC-associated viral kinase pUL97 suggested an intranuclear NEC-capsid interaction. Staining patterns with phospho-specific lamin A/C antibodies are compatible with earlier postulates of targeted capsid egress at lamina-depleted areas. Important data were provided by co-immunoprecipitation and in vitro kinase analyses using lysates from HCMV-infected cells, nuclear fractions, or infectious virions. Data strongly suggest that nuclear capsids interact with pUL53 and pUL97. Combined, the findings support a refined concept of HCMV nuclear trafficking and NEC-capsid interaction.

  18. Human Cytomegalovirus Nuclear Capsids Associate with the Core Nuclear Egress Complex and the Viral Protein Kinase pUL97

    Directory of Open Access Journals (Sweden)

    Jens Milbradt

    2018-01-01

    Full Text Available The nuclear phase of herpesvirus replication is regulated through the formation of regulatory multi-component protein complexes. Viral genomic replication is followed by nuclear capsid assembly, DNA encapsidation and nuclear egress. The latter has been studied intensely pointing to the formation of a viral core nuclear egress complex (NEC that recruits a multimeric assembly of viral and cellular factors for the reorganization of the nuclear envelope. To date, the mechanism of the association of human cytomegalovirus (HCMV capsids with the NEC, which in turn initiates the specific steps of nuclear capsid budding, remains undefined. Here, we provide electron microscopy-based data demonstrating the association of both nuclear capsids and NEC proteins at nuclear lamina budding sites. Specifically, immunogold labelling of the core NEC constituent pUL53 and NEC-associated viral kinase pUL97 suggested an intranuclear NEC-capsid interaction. Staining patterns with phospho-specific lamin A/C antibodies are compatible with earlier postulates of targeted capsid egress at lamina-depleted areas. Important data were provided by co-immunoprecipitation and in vitro kinase analyses using lysates from HCMV-infected cells, nuclear fractions, or infectious virions. Data strongly suggest that nuclear capsids interact with pUL53 and pUL97. Combined, the findings support a refined concept of HCMV nuclear trafficking and NEC-capsid interaction.

  19. Hepatitis C virus core protein targets 4E-BP1 expression and phosphorylation and potentiates Myc-induced liver carcinogenesis in transgenic mice.

    Science.gov (United States)

    Abdallah, Cosette; Lejamtel, Charlène; Benzoubir, Nassima; Battaglia, Serena; Sidahmed-Adrar, Nazha; Desterke, Christophe; Lemasson, Matthieu; Rosenberg, Arielle R; Samuel, Didier; Bréchot, Christian; Pflieger, Delphine; Le Naour, François; Bourgeade, Marie-Françoise

    2017-08-22

    Hepatitis C virus (HCV) is a leading cause of liver diseases including the development of hepatocellular carcinoma (HCC). Particularly, core protein has been involved in HCV-related liver pathologies. However, the impact of HCV core on signaling pathways supporting the genesis of HCC remains largely elusive. To decipher the host cell signaling pathways involved in the oncogenic potential of HCV core, a global quantitative phosphoproteomic approach was carried out. This study shed light on novel differentially phosphorylated proteins, in particular several components involved in translation. Among the eukaryotic initiation factors that govern the translational machinery, 4E-BP1 represents a master regulator of protein synthesis that is associated with the development and progression of cancers due to its ability to increase protein expression of oncogenic pathways. Enhanced levels of 4E-BP1 in non-modified and phosphorylated forms were validated in human hepatoma cells and in mouse primary hepatocytes expressing HCV core, in the livers of HCV core transgenic mice as well as in HCV-infected human primary hepatocytes. The contribution of HCV core in carcinogenesis and the status of 4E-BP1 expression and phosphorylation were studied in HCV core/Myc double transgenic mice. HCV core increased the levels of 4E-BP1 expression and phosphorylation and significantly accelerated the onset of Myc-induced tumorigenesis in these double transgenic mice. These results reveal a novel function of HCV core in liver carcinogenesis potentiation. They position 4E-BP1 as a tumor-specific target of HCV core and support the involvement of the 4E-BP1/eIF4E axis in hepatocarcinogenesis.

  20. Coupled cell-free synthesis, segregation, and core glycosylation of a secretory protein.

    Science.gov (United States)

    Lingappa, V R; Lingappa, J R; Prasad, R; Ebner, K E; Blobel, G

    1978-05-01

    mRNA from rat mammary glands 13-15 days post partum was translated in a wheat germ cell-free system either in the absence or in the presence of ribosome-denuded membranes prepared from isolated rough microsomes of dog pancreas. Newly synthesized alpha-lactalbumin was identified by immunoprecipitation with a monospecific rabbit antiserum against rat alpha-lactalbumin and was characterized by partial amino-terminal sequence determination and by lectin affinity chromatography. In the absence of membranes a presumably unglycosylated form of alpha-lactalbumin was synthesized that bound neither to concanavalin A-Sepharose nor to Ricinus communis lectin-agarose and that contained an amino-terminal signal peptide region comprising 19 amino acid residues. In the presence of membranes a processed form was synthesized that lacked the signal peptide portion and that had an amino-terminal sequence identical to that of mature alpha-lactalbumin. Furthermore, this processed form was found to be segregated, presumably within the microsomal vesicles, because it was resistant to post-translational proteolysis. It was also found to be glycosylated, and because it bound to concanavalin A-Sepharose, from which it could be eluted specifically by alpha-methyl mannoside, but not to R. communis lectin-agarose, it was presumably core-glycosylated. Processing, segregation, and core glycosylation were observed to proceed only when membranes were present during translation and not when they were added after translation.

  1. The duck hepatitis B virus polymerase and core proteins accumulate in different patterns from their common mRNA

    International Nuclear Information System (INIS)

    Yao Ermei; Schaller, Heinz; Tavis, John E.

    2003-01-01

    Hepadnaviral reverse transcription occurs in capsids in which the core (C) protein surrounds the reverse transcriptase (P) and pregenomic RNA (pgRNA). We analyzed the accumulation patterns of duck hepatitis B virus P, C, and pgRNA in transfected LMH cells, infected primary duck hepatocytes (PDH), and infected duck liver. In all three systems, P accumulated over time in a different pattern compared with C, despite translation of both proteins from the pgRNA. Although the accumulation patterns of the proteins varied between the systems, in each case P became detectable at the same time or earlier than C and the ratio of P relative to C dropped with time. These accumulation patterns were consistent with the translation rates and half-lives of P and C. Comparing the translation rates of P and C with the pgRNA level over time revealed that translation of P and C was negatively regulated in LMH cells. These data provide a framework for comparing replication studies performed in LMH cells, PDHs and ducks

  2. Structure of the protein core of translation initiation factor 2 in apo, GTP-bound and GDP-bound forms

    International Nuclear Information System (INIS)

    Simonetti, Angelita; Marzi, Stefano; Fabbretti, Attilio; Hazemann, Isabelle; Jenner, Lasse; Urzhumtsev, Alexandre; Gualerzi, Claudio O.; Klaholz, Bruno P.

    2013-01-01

    The crystal structures of the eubacterial translation initiation factor 2 in apo form and with bound GDP and GTP reveal conformational changes upon nucleotide binding and hydrolysis, notably of the catalytically important histidine in the switch II region. Translation initiation factor 2 (IF2) is involved in the early steps of bacterial protein synthesis. It promotes the stabilization of the initiator tRNA on the 30S initiation complex (IC) and triggers GTP hydrolysis upon ribosomal subunit joining. While the structure of an archaeal homologue (a/eIF5B) is known, there are significant sequence and functional differences in eubacterial IF2, while the trimeric eukaryotic IF2 is completely unrelated. Here, the crystal structure of the apo IF2 protein core from Thermus thermophilus has been determined by MAD phasing and the structures of GTP and GDP complexes were also obtained. The IF2–GTP complex was trapped by soaking with GTP in the cryoprotectant. The structures revealed conformational changes of the protein upon nucleotide binding, in particular in the P-loop region, which extend to the functionally relevant switch II region. The latter carries a catalytically important and conserved histidine residue which is observed in different conformations in the GTP and GDP complexes. Overall, this work provides the first crystal structure of a eubacterial IF2 and suggests that activation of GTP hydrolysis may occur by a conformational repositioning of the histidine residue

  3. Structure of the protein core of translation initiation factor 2 in apo, GTP-bound and GDP-bound forms

    Energy Technology Data Exchange (ETDEWEB)

    Simonetti, Angelita [IGBMC (Institute of Genetics and of Molecular and Cellular Biology), Centre National de la Recherche Scientifique (CNRS) UMR 7104/Institut National de la Santé de la Recherche Médicale - INSERM U964/Université de Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch (France); Marzi, Stefano [Architecture et Réactivité de l’ARN, UPR 9002 CNRS, IBMC (Institute of Molecular and Cellular Biology), 15 Rue R. Descartes, 67084 Strasbourg, France, Université de Strasbourg, 67000 Strasbourg (France); Fabbretti, Attilio [University of Camerino, 62032 Camerino (Monaco) (Italy); Hazemann, Isabelle; Jenner, Lasse [IGBMC (Institute of Genetics and of Molecular and Cellular Biology), Centre National de la Recherche Scientifique (CNRS) UMR 7104/Institut National de la Santé de la Recherche Médicale -INSERM U964/Université de Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch (France); Urzhumtsev, Alexandre [IGBMC (Institute of Genetics and of Molecular and Cellular Biology), Centre National de la Recherche Scientifique (CNRS) UMR 7104/Institut National de la Santé de la Recherche Médicale - INSERM U964/Université de Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch (France); Université de Lorraine, 54506 Vandoeuvre-lès-Nancy (France); Gualerzi, Claudio O. [University of Camerino, 62032 Camerino (Monaco) (Italy); Klaholz, Bruno P., E-mail: klaholz@igbmc.fr [IGBMC (Institute of Genetics and of Molecular and Cellular Biology), Centre National de la Recherche Scientifique (CNRS) UMR 7104/Institut National de la Santé de la Recherche Médicale - INSERM U964/Université de Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch (France)

    2013-06-01

    The crystal structures of the eubacterial translation initiation factor 2 in apo form and with bound GDP and GTP reveal conformational changes upon nucleotide binding and hydrolysis, notably of the catalytically important histidine in the switch II region. Translation initiation factor 2 (IF2) is involved in the early steps of bacterial protein synthesis. It promotes the stabilization of the initiator tRNA on the 30S initiation complex (IC) and triggers GTP hydrolysis upon ribosomal subunit joining. While the structure of an archaeal homologue (a/eIF5B) is known, there are significant sequence and functional differences in eubacterial IF2, while the trimeric eukaryotic IF2 is completely unrelated. Here, the crystal structure of the apo IF2 protein core from Thermus thermophilus has been determined by MAD phasing and the structures of GTP and GDP complexes were also obtained. The IF2–GTP complex was trapped by soaking with GTP in the cryoprotectant. The structures revealed conformational changes of the protein upon nucleotide binding, in particular in the P-loop region, which extend to the functionally relevant switch II region. The latter carries a catalytically important and conserved histidine residue which is observed in different conformations in the GTP and GDP complexes. Overall, this work provides the first crystal structure of a eubacterial IF2 and suggests that activation of GTP hydrolysis may occur by a conformational repositioning of the histidine residue.

  4. Hepatitis C virus core protein regulates p300/CBP co-activation function. Possible role in the regulation of NF-AT1 transcriptional activity

    International Nuclear Information System (INIS)

    Gomez-Gonzalo, Marta; Benedicto, Ignacio; Carretero, Marta; Lara-Pezzi, Enrique; Maldonado-Rodriguez, Alejandra; Moreno-Otero, Ricardo; Lai, Michael M.C.; Lopez-Cabrera, Manuel

    2004-01-01

    Hepatitis C virus (HCV) core is a viral structural protein; it also participates in some cellular processes, including transcriptional regulation. However, the mechanisms of core-mediated transcriptional regulation remain poorly understood. Oncogenic virus proteins often target p300/CBP, a known co-activator of a wide variety of transcription factors, to regulate the expression of cellular and viral genes. Here we demonstrate, for the first time, that HCV core protein interacts with p300/CBP and enhances both its acetyl-transferase and transcriptional activities. In addition, we demonstrate that nuclear core protein activates the NH 2 -terminal transcription activation domain (TAD) of NF-AT1 in a p300/CBP-dependent manner. We propose a model in which core protein regulates the co-activation function of p300/CBP and activates NF-AT1, and probably other p300/CBP-regulated transcription factors, by a novel mechanism involving the regulation of the acetylation state of histones and/or components of the transcriptional machinery

  5. Tandem fusion of hepatitis B core antigen allows assembly of virus-like particles in bacteria and plants with enhanced capacity to accommodate foreign proteins.

    Directory of Open Access Journals (Sweden)

    Hadrien Peyret

    Full Text Available The core protein of the hepatitis B virus, HBcAg, assembles into highly immunogenic virus-like particles (HBc VLPs when expressed in a variety of heterologous systems. Specifically, the major insertion region (MIR on the HBcAg protein allows the insertion of foreign sequences, which are then exposed on the tips of surface spike structures on the outside of the assembled particle. Here, we present a novel strategy which aids the display of whole proteins on the surface of HBc particles. This strategy, named tandem core, is based on the production of the HBcAg dimer as a single polypeptide chain by tandem fusion of two HBcAg open reading frames. This allows the insertion of large heterologous sequences in only one of the two MIRs in each spike, without compromising VLP formation. We present the use of tandem core technology in both plant and bacterial expression systems. The results show that tandem core particles can be produced with unmodified MIRs, or with one MIR in each tandem dimer modified to contain the entire sequence of GFP or of a camelid nanobody. Both inserted proteins are correctly folded and the nanobody fused to the surface of the tandem core particle (which we name tandibody retains the ability to bind to its cognate antigen. This technology paves the way for the display of natively folded proteins on the surface of HBc particles either through direct fusion or through non-covalent attachment via a nanobody.

  6. Role of Decorin Core Protein in Collagen Organisation in Congenital Stromal Corneal Dystrophy (CSCD.

    Directory of Open Access Journals (Sweden)

    Christina S Kamma-Lorger

    Full Text Available The role of Decorin in organising the extracellular matrix was examined in normal human corneas and in corneas from patients with Congenital Stromal Corneal Dystrophy (CSCD. In CSCD, corneal clouding occurs due to a truncating mutation (c.967delT in the decorin (DCN gene. Normal human Decorin protein and the truncated one were reconstructed in silico using homology modelling techniques to explore structural changes in the diseased protein. Corneal CSCD specimens were also examined using 3-D electron tomography and Small Angle X-ray diffraction (SAXS, to image the collagen-proteoglycan arrangement and to quantify fibrillar diameters, respectively. Homology modelling showed that truncated Decorin had a different spatial geometry to the normal one, with the truncation removing a major part of the site that interacts with collagen, compromising its ability to bind effectively. Electron tomography showed regions of abnormal stroma, where collagen fibrils came together to form thicker fibrillar structures, showing that Decorin plays a key role in the maintenance of the order in the normal corneal extracellular matrix. Average diameter of individual fibrils throughout the thickness of the cornea however remained normal.

  7. The diverse functions of the hepatitis B core/capsid protein (HBc) in the viral life cycle: Implications for the development of HBc-targeting antivirals.

    Science.gov (United States)

    Diab, Ahmed; Foca, Adrien; Zoulim, Fabien; Durantel, David; Andrisani, Ourania

    2018-01-01

    Virally encoded proteins have evolved to perform multiple functions, and the core protein (HBc) of the hepatitis B virus (HBV) is a perfect example. While HBc is the structural component of the viral nucleocapsid, additional novel functions for the nucleus-localized HBc have recently been described. These results extend for HBc, beyond its structural role, a regulatory function in the viral life cycle and potentially a role in pathogenesis. In this article, we review the diverse roles of HBc in HBV replication and pathogenesis, emphasizing how the unique structure of this protein is key to its various functions. We focus in particular on recent advances in understanding the significance of HBc phosphorylations, its interaction with host proteins and the role of HBc in regulating the transcription of host genes. We also briefly allude to the emerging niche for new direct-acting antivirals targeting HBc, known as Core (protein) Allosteric Modulators (CAMs). Copyright © 2017 Elsevier B.V. All rights reserved.

  8. A single amino acid substitution in the core protein of West Nile virus increases resistance to acidotropic compounds.

    Directory of Open Access Journals (Sweden)

    Miguel A Martín-Acebes

    Full Text Available West Nile virus (WNV is a worldwide distributed mosquito-borne flavivirus that naturally cycles between birds and mosquitoes, although it can infect multiple vertebrate hosts including horses and humans. This virus is responsible for recurrent epidemics of febrile illness and encephalitis, and has recently become a global concern. WNV requires to transit through intracellular acidic compartments at two different steps to complete its infectious cycle. These include fusion between the viral envelope and the membrane of endosomes during viral entry, and virus maturation in the trans-Golgi network. In this study, we followed a genetic approach to study the connections between viral components and acidic pH. A WNV mutant with increased resistance to the acidotropic compound NH4Cl, which blocks organelle acidification and inhibits WNV infection, was selected. Nucleotide sequencing revealed that this mutant displayed a single amino acid substitution (Lys 3 to Glu on the highly basic internal capsid or core (C protein. The functional role of this replacement was confirmed by its introduction into a WNV infectious clone. This single amino acid substitution also increased resistance to other acidification inhibitor (concanamycin A and induced a reduction of the neurovirulence in mice. Interestingly, a naturally occurring accompanying mutation found on prM protein abolished the resistant phenotype, supporting the idea of a genetic crosstalk between the internal C protein and the external glycoproteins of the virion. The findings here reported unveil a non-previously assessed connection between the C viral protein and the acidic pH necessary for entry and proper exit of flaviviruses.

  9. A single amino acid substitution in the core protein of West Nile virus increases resistance to acidotropic compounds.

    Science.gov (United States)

    Martín-Acebes, Miguel A; Blázquez, Ana-Belén; de Oya, Nereida Jiménez; Escribano-Romero, Estela; Shi, Pei-Yong; Saiz, Juan-Carlos

    2013-01-01

    West Nile virus (WNV) is a worldwide distributed mosquito-borne flavivirus that naturally cycles between birds and mosquitoes, although it can infect multiple vertebrate hosts including horses and humans. This virus is responsible for recurrent epidemics of febrile illness and encephalitis, and has recently become a global concern. WNV requires to transit through intracellular acidic compartments at two different steps to complete its infectious cycle. These include fusion between the viral envelope and the membrane of endosomes during viral entry, and virus maturation in the trans-Golgi network. In this study, we followed a genetic approach to study the connections between viral components and acidic pH. A WNV mutant with increased resistance to the acidotropic compound NH4Cl, which blocks organelle acidification and inhibits WNV infection, was selected. Nucleotide sequencing revealed that this mutant displayed a single amino acid substitution (Lys 3 to Glu) on the highly basic internal capsid or core (C) protein. The functional role of this replacement was confirmed by its introduction into a WNV infectious clone. This single amino acid substitution also increased resistance to other acidification inhibitor (concanamycin A) and induced a reduction of the neurovirulence in mice. Interestingly, a naturally occurring accompanying mutation found on prM protein abolished the resistant phenotype, supporting the idea of a genetic crosstalk between the internal C protein and the external glycoproteins of the virion. The findings here reported unveil a non-previously assessed connection between the C viral protein and the acidic pH necessary for entry and proper exit of flaviviruses.

  10. The dense core vesicle protein IA-2, but not IA-2β, is required for active avoidance learning.

    Science.gov (United States)

    Carmona, G N; Nishimura, T; Schindler, C W; Panlilio, L V; Notkins, A L

    2014-06-06

    The islet-antigens IA-2 and IA-2β are major autoantigens in type-1 diabetes and transmembrane proteins in dense core vesicles (DCV). Recently we showed that deletion of both IA-2 and IA-2β alters the secretion of hormones and neurotransmitters and impairs behavior and learning. The present study was designed to evaluate the contribution to learning of each of these genes by using single knockout (SKO) and double knockout (DKO) mice in an active avoidance test. After 5 days of training, wild-type (WT) mice showed 60-70% active avoidance responses, whereas the DKO mice showed only 10-15% active avoidance responses. The degree of active avoidance responses in the IA-2 SKO mice was similar to that of the DKO mice, but in contrast, the IA-2β SKO mice behaved like WT mice showing 60-70% active avoidance responses. Molecular studies revealed a marked decrease in the phosphorylation of the cAMP response element-binding protein (CREB) and Ca(2+)/calmodulin-dependent protein kinase II (CAMKII) in the striatum and hippocampus of the IA-2 SKO and DKO mice, but not in the IA-2β SKO mice. To evaluate the role of CREB and CAMKII in the SKO and DKO mice, GBR-12909, which selectively blocks the dopamine uptake transporter and increases CREB and CAMKII phosphorylation, was administered. GBR-12909 restored the phosphorylation of CREB and CAMKII and increased active avoidance learning in the DKO and IA-2 SKO to near the normal levels found in the WT and IA-2β SKO mice. We conclude that in the absence of the DCV protein IA-2, active avoidance learning is impaired. Published by Elsevier Ltd.

  11. The SNARE protein vti1a functions in dense-core vesicle biogenesis

    DEFF Research Database (Denmark)

    Walter, Alexander M; Kurps, Julia; de Wit, Heidi

    2014-01-01

    overlapping with syntaxin-6. Exocytosis is impaired in vti1a null cells, partly due to fewer Ca(2+)-channels at the plasma membrane, partly due to fewer vesicles of reduced size and synaptobrevin-2 content. In contrast, release kinetics and Ca(2+)-sensitivity remain unchanged, indicating that the final fusion......The SNARE protein vti1a is proposed to drive fusion of intracellular organelles, but recent data also implicated vti1a in exocytosis. Here we show that vti1a is absent from mature secretory vesicles in adrenal chromaffin cells, but localizes to a compartment near the trans-Golgi network, partially...... reaction leading to transmitter release is unperturbed. Additional deletion of the closest related SNARE, vti1b, does not exacerbate the vti1a phenotype, and vti1b null cells show no secretion defects, indicating that vti1b does not participate in exocytosis. Long-term re-expression of vti1a (days...

  12. Different intracellular distribution of avian reovirus core protein sigmaA in cells of avian and mammalian origin

    International Nuclear Information System (INIS)

    Vázquez-Iglesias, Lorena; Lostalé-Seijo, Irene; Martínez-Costas, José; Benavente, Javier

    2012-01-01

    A comparative analysis of the intracellular distribution of avian reovirus (ARV) core protein sigmaA in cells of avian and mammalian origin revealed that, whereas the viral protein accumulates in the cytoplasm and nucleolus of avian cells, most sigmaA concentrates in the nucleoplasm of mammalian cells in tight association with the insoluble nuclear matrix fraction. Our results further showed that sigmaA becomes arrested in the nucleoplasm of mammalian cells via association with mammalian cell-specific factors and that this association prevents nucleolar targeting. Inhibition of RNA polymerase II activity, but not of RNA polymerase I activity, in infected mammalian cells induces nucleus-to-cytoplasm sigmaA translocation through a CRM1- and RanGTP-dependent mechanism, yet a heterokaryon assay suggests that sigmaA does not shuttle between the nucleus and cytoplasm. The scarcity of sigmaA in cytoplasmic viral factories of infected mammalian cells could be one of the factors contributing to limited ARV replication in mammalian cells.

  13. Different intracellular distribution of avian reovirus core protein sigmaA in cells of avian and mammalian origin

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez-Iglesias, Lorena; Lostale-Seijo, Irene; Martinez-Costas, Jose [Departamento de Bioquimica y Biologia Molecular, Facultad de Farmacia, y Centro Singular de Investigacion en Quimica Biologica y Materiales Moleculares (CIQUS), Universidad de Santiago de Compostela, 15782-Santiago de Compostela (Spain); Benavente, Javier, E-mail: franciscojavier.benavente@usc.es [Departamento de Bioquimica y Biologia Molecular, Facultad de Farmacia, y Centro Singular de Investigacion en Quimica Biologica y Materiales Moleculares (CIQUS), Universidad de Santiago de Compostela, 15782-Santiago de Compostela (Spain)

    2012-10-25

    A comparative analysis of the intracellular distribution of avian reovirus (ARV) core protein sigmaA in cells of avian and mammalian origin revealed that, whereas the viral protein accumulates in the cytoplasm and nucleolus of avian cells, most sigmaA concentrates in the nucleoplasm of mammalian cells in tight association with the insoluble nuclear matrix fraction. Our results further showed that sigmaA becomes arrested in the nucleoplasm of mammalian cells via association with mammalian cell-specific factors and that this association prevents nucleolar targeting. Inhibition of RNA polymerase II activity, but not of RNA polymerase I activity, in infected mammalian cells induces nucleus-to-cytoplasm sigmaA translocation through a CRM1- and RanGTP-dependent mechanism, yet a heterokaryon assay suggests that sigmaA does not shuttle between the nucleus and cytoplasm. The scarcity of sigmaA in cytoplasmic viral factories of infected mammalian cells could be one of the factors contributing to limited ARV replication in mammalian cells.

  14. Coevolved Mutations Reveal Distinct Architectures for Two Core Proteins in the Bacterial Flagellar Motor.

    Directory of Open Access Journals (Sweden)

    Alessandro Pandini

    Full Text Available Switching of bacterial flagellar rotation is caused by large domain movements of the FliG protein triggered by binding of the signal protein CheY to FliM. FliG and FliM form adjacent multi-subunit arrays within the basal body C-ring. The movements alter the interaction of the FliG C-terminal (FliGC "torque" helix with the stator complexes. Atomic models based on the Salmonella entrovar C-ring electron microscopy reconstruction have implications for switching, but lack consensus on the relative locations of the FliG armadillo (ARM domains (amino-terminal (FliGN, middle (FliGM and FliGC as well as changes during chemotaxis. The generality of the Salmonella model is challenged by the variation in motor morphology and response between species. We studied coevolved residue mutations to determine the unifying elements of switch architecture. Residue interactions, measured by their coevolution, were formalized as a network, guided by structural data. Our measurements reveal a common design with dedicated switch and motor modules. The FliM middle domain (FliMM has extensive connectivity most simply explained by conserved intra and inter-subunit contacts. In contrast, FliG has patchy, complex architecture. Conserved structural motifs form interacting nodes in the coevolution network that wire FliMM to the FliGC C-terminal, four-helix motor module (C3-6. FliG C3-6 coevolution is organized around the torque helix, differently from other ARM domains. The nodes form separated, surface-proximal patches that are targeted by deleterious mutations as in other allosteric systems. The dominant node is formed by the EHPQ motif at the FliMMFliGM contact interface and adjacent helix residues at a central location within FliGM. The node interacts with nodes in the N-terminal FliGc α-helix triad (ARM-C and FliGN. ARM-C, separated from C3-6 by the MFVF motif, has poor intra-network connectivity consistent with its variable orientation revealed by structural data. ARM

  15. Structural Insight into the Core of CAD, the Multifunctional Protein Leading De Novo Pyrimidine Biosynthesis.

    Science.gov (United States)

    Moreno-Morcillo, María; Grande-García, Araceli; Ruiz-Ramos, Alba; Del Caño-Ochoa, Francisco; Boskovic, Jasminka; Ramón-Maiques, Santiago

    2017-06-06

    CAD, the multifunctional protein initiating and controlling de novo biosynthesis of pyrimidines in animals, self-assembles into ∼1.5 MDa hexamers. The structures of the dihydroorotase (DHO) and aspartate transcarbamoylase (ATC) domains of human CAD have been previously determined, but we lack information on how these domains associate and interact with the rest of CAD forming a multienzymatic unit. Here, we prove that a construct covering human DHO and ATC oligomerizes as a dimer of trimers and that this arrangement is conserved in CAD-like from fungi, which holds an inactive DHO-like domain. The crystal structures of the ATC trimer and DHO-like dimer from the fungus Chaetomium thermophilum confirm the similarity with the human CAD homologs. These results demonstrate that, despite being inactive, the fungal DHO-like domain has a conserved structural function. We propose a model that sets the DHO and ATC complex as the central element in the architecture of CAD. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Impact of tuberculosis treatment on CD4 cell count, HIV RNA, and p24 antigen in patients with HIV and tuberculosis

    DEFF Research Database (Denmark)

    Wejse, Christian; Furtado, A.; Camara, C.

    2013-01-01

    To describe HIV RNA levels during tuberculosis (TB) infection in patients co-infected with TB and HIV. Moreover, to examine the p24 antigen profile during TB treatment.......To describe HIV RNA levels during tuberculosis (TB) infection in patients co-infected with TB and HIV. Moreover, to examine the p24 antigen profile during TB treatment....

  17. HCV core protein-induced down-regulation of microRNA-152 promoted aberrant proliferation by regulating Wnt1 in HepG2 cells.

    Directory of Open Access Journals (Sweden)

    Shifeng Huang

    Full Text Available Hepatitis C virus (HCV has been reported to regulate cellular microRNAs (miRNAs. The HCV core protein is considered to be a potential oncoprotein in HCV-related hepatocellular carcinoma (HCV-HCC, but HCV core-regulated miRNAs are largely unknown. Our preliminary experiments revealed significant down-regulation of microRNA-152 (miR-152 by HCV core protein in HepG2 cells. Through target gene prediction softwares, Wnt1 was predicted to be a potential target of miR-152. The present study was initiated to investigate whether miR-152 is aberrantly regulated by the HCV core protein, and involved in the regulation of the aberrant proliferation of HCV-HCC cells.MiR-152 levels were examined by stem-loop real-time RT-PCR (SLqRT-PCR. Cell proliferation was analyzed by MTT and colony formation assay. Cell cycle analysis was performed by flow cytometry. Luciferase reporter assay was conducted to confirm miRNA-target association. Wnt1 expression was determined by real-time qPCR and Western blotting.HCV core protein significantly suppressed miR-152 expression, and led to significant Wnt1 up-regulation with a concomitant aberrantly promoted proliferation. Moreover, we validated that miR-152 inhibition promoted, while miR-152 mimics inhibited cell proliferation. Using, qRT-PCR and western blot, Wnt1 was demonstrated to be regulated by miR-152. Luciferase activity assay showed that while miR-152 mimics significantly reduced the luciferase activity by 83.76% (P<0.0001, miR-152 inhibitor showed no effect on luciferase reporter. Most notably, salvage expression of miR-152 after Ad-HCV core infection for 24 h almost totally reversed the proliferation-promoting effect of the HCV core protein, and meanwhile, reduced the expression of both Wnt1 mRNA and protein to basal levels.These findings provide important evidence that the reduced miR-152 expression by HCV core protein can indirectly lose an inhibitory effect on Wnt1, which might, at least partially lead to cell

  18. Quantitative Comparison of Dense-Core Amyloid Plaque Accumulation in Amyloid-β Precursor Protein Transgenic Mice

    Science.gov (United States)

    Liu, Peng; Reichl, John H.; Rao, Eshaan R.; McNellis, Brittany M.; Huang, Eric S.; Hemmy, Laura S.; Forster, Colleen L.; Kuskowski, Michael A.; Borchelt, David R.; Vassar, Robert; Ashe, Karen H.; Zahs, Kathleen R.

    2016-01-01

    There exist several dozen lines of transgenic mice that express human amyloid-β precursor protein (AβPP) with Alzheimer’s disease (AD)-linked mutations. AβPP transgenic mouse lines differ in the types and amounts of Aβ that they generate and in their spatiotemporal patterns of expression of Aβ assemblies, providing a toolkit to study Aβ amyloidosis and the influence of Aβ aggregation on brain function. More complete quantitative descriptions of the types of Aβ assemblies present in transgenic mice and in humans during disease progression should add to our understanding of how Aβ toxicity in mice relates to the pathogenesis of AD. Here, we provide a direct quantitative comparison of amyloid plaque burdens and plaque sizes in four lines of AβPP transgenic mice. We measured the fraction of cortex and hippocampus occupied by dense-core plaques, visualized by staining with Thioflavin S, in mice from young adulthood through advanced age. We found that the plaque burdens among the transgenic lines varied by an order of magnitude: at 15 months of age, the oldest age studied, the median cortical plaque burden in 5XFAD mice was already ~4.5 times that of 21-month Tg2576 mice and ~15 times that of 21–24-month rTg9191 mice. Plaque-size distributions changed across the lifespan in a line- and region-dependent manner. We also compared the dense-core plaque burdens in the mice to those measured in a set of pathologically-confirmed AD cases from the Nun Study. Cortical plaque burdens in Tg2576, APPSwePS1ΔE9, and 5XFAD mice eventually far exceeded those measured in the human cohort. PMID:28059792

  19. Quantitative Comparison of Dense-Core Amyloid Plaque Accumulation in Amyloid-β Protein Precursor Transgenic Mice.

    Science.gov (United States)

    Liu, Peng; Reichl, John H; Rao, Eshaan R; McNellis, Brittany M; Huang, Eric S; Hemmy, Laura S; Forster, Colleen L; Kuskowski, Michael A; Borchelt, David R; Vassar, Robert; Ashe, Karen H; Zahs, Kathleen R

    2017-01-01

    There exist several dozen lines of transgenic mice that express human amyloid-β protein precursor (AβPP) with Alzheimer's disease (AD)-linked mutations. AβPP transgenic mouse lines differ in the types and amounts of Aβ that they generate and in their spatiotemporal patterns of expression of Aβ assemblies, providing a toolkit to study Aβ amyloidosis and the influence of Aβ aggregation on brain function. More complete quantitative descriptions of the types of Aβ assemblies present in transgenic mice and in humans during disease progression should add to our understanding of how Aβ toxicity in mice relates to the pathogenesis of AD. Here, we provide a direct quantitative comparison of amyloid plaque burdens and plaque sizes in four lines of AβPP transgenic mice. We measured the fraction of cortex and hippocampus occupied by dense-core plaques, visualized by staining with Thioflavin S, in mice from young adulthood through advanced age. We found that the plaque burdens among the transgenic lines varied by an order of magnitude: at 15 months of age, the oldest age studied, the median cortical plaque burden in 5XFAD mice was already ∼4.5 times that of 21-month-old Tg2576 mice and ∼15 times that of 21-24-month-old rTg9191 mice. Plaque-size distributions changed across the lifespan in a line- and region-dependent manner. We also compared the dense-core plaque burdens in the mice to those measured in a set of pathologically-confirmed AD cases from the Nun Study. Cortical plaque burdens in Tg2576, APPSwePS1ΔE9, and 5XFAD mice eventually far exceeded those measured in the human cohort.

  20. Evaluation of a recombinant p24 antigen for the detection of Feline Immunodeficiency Virus-specific antibodies Avaliação do antígeno recombinante p24 para a detecção de anticorpos específicos do Vírus da Imunodeficiência Felina

    Directory of Open Access Journals (Sweden)

    Carlos Mazur

    2010-10-01

    Full Text Available Feline Immunodeficiency Virus is a worldwide infection and is considered a significant pathogen. The diagnosis of FIV infections is mainly based on commercially available rapid tests that are highly expensive in Brazil, hence it is rarely performed in the country. Furthermore, lentiviruses grow slowly and poorly in tissue cultures, making the production of viral antigen by classic means and thus the establishment of FIV immunodiagnosis impracticable. In order to deal with this, recombinant DNA techniques were adopted to produce the protein p24, a viral capsid antigen. The protein's reactivity evaluation analyzed by Western blot indicated that this recombinant antigen can be a useful tool for the immunodiagnostic of FIV infections.O vírus da imunodeficiência felina tem distribuição mundial e é considerado um patógeno significativo. No Brasil, a prática diagnóstica é baseada principalmente em teste rápidos, importados e de custo elevado, disponíveis comercialmente. Devido ao seu custo proibitivo em nosso país, o diagnóstico da infecção pelo FIV é raramente realizado. Ademais, os lentivírus se multiplicam lenta e pobremente em cultura de células, o que torna a produção de antígeno por meios clássicos e o estabelecimento do imunodiagnóstico impraticável. Com o objetivo de lidar com esta questão, técnicas de DNA recombinante foram utilizadas para produção de um antígeno do capsídeo viral, a proteína p24. A avaliação da reatividade realizada por Western blot indicou que este antígeno recombinante pode ser útil para o imunodiagnóstico de infecções pelo FIV.

  1. An amino-terminal segment of hantavirus nucleocapsid protein presented on hepatitis B virus core particles induces a strong and highly cross-reactive antibody response in mice

    International Nuclear Information System (INIS)

    Geldmacher, Astrid; Skrastina, Dace; Petrovskis, Ivars; Borisova, Galina; Berriman, John A.; Roseman, Alan M.; Crowther, R. Anthony; Fischer, Jan; Musema, Shamil; Gelderblom, Hans R.; Lundkvist, Aake; Renhofa, Regina; Ose, Velta; Krueger, Detlev H.; Pumpens, Paul; Ulrich, Rainer

    2004-01-01

    Previously, we have demonstrated that hepatitis B virus (HBV) core particles tolerate the insertion of the amino-terminal 120 amino acids (aa) of the Puumala hantavirus nucleocapsid (N) protein. Here, we demonstrate that the insertion of 120 amino-terminal aa of N proteins from highly virulent Dobrava and Hantaan hantaviruses allows the formation of chimeric core particles. These particles expose the inserted foreign protein segments, at least in part, on their surface. Analysis by electron cryomicroscopy of chimeric particles harbouring the Puumala virus (PUUV) N segment revealed 90% T = 3 and 10% T = 4 shells. A map computed from T = 3 shells shows additional density splaying out from the tips of the spikes producing the effect of an extra shell of density at an outer radius compared with wild-type shells. The inserted Puumala virus N protein segment is flexibly linked to the core spikes and only partially icosahedrally ordered. Immunisation of mice of two different haplotypes (BALB/c and C57BL/6) with chimeric core particles induces a high-titered and highly cross-reactive N-specific antibody response in both mice strains

  2. Liver cancer-derived hepatitis C virus core proteins shift TGF-beta responses from tumor suppression to epithelial-mesenchymal transition.

    Directory of Open Access Journals (Sweden)

    Serena Battaglia

    Full Text Available BACKGROUND: Chronic hepatitis C virus (HCV infection and associated liver cirrhosis represent a major risk factor for hepatocellular carcinoma (HCC development. TGF-beta is an important driver of liver fibrogenesis and cancer; however, its actual impact in human cancer progression is still poorly known. The aim of this study was to investigate the role of HCC-derived HCV core natural variants on cancer progression through their impact on TGF-beta signaling. PRINCIPAL FINDINGS: We provide evidence that HCC-derived core protein expression in primary human or mouse hepatocyte alleviates TGF-beta responses in terms or growth inhibition or apoptosis. Instead, in these hepatocytes TGF-beta was still able to induce an epithelial to mesenchymal transition (EMT, a process that contributes to the promotion of cell invasion and metastasis. Moreover, we demonstrate that different thresholds of Smad3 activation dictate the TGF-beta responses in hepatic cells and that HCV core protein, by decreasing Smad3 activation, may switch TGF-beta growth inhibitory effects to tumor promoting responses. CONCLUSION/SIGNIFICANCE: Our data illustrate the capacity of hepatocytes to develop EMT and plasticity under TGF-beta, emphasize the role of HCV core protein in the dynamic of these effects and provide evidence for a paradigm whereby a viral protein implicated in oncogenesis is capable to shift TGF-beta responses from cytostatic effects to EMT development.

  3. Room-temperature synthesis of core-shell structured magnetic covalent organic frameworks for efficient enrichment of peptides and simultaneous exclusion of proteins.

    Science.gov (United States)

    Lin, Guo; Gao, Chaohong; Zheng, Qiong; Lei, Zhixian; Geng, Huijuan; Lin, Zian; Yang, Huanghao; Cai, Zongwei

    2017-03-28

    Core-shell structured magnetic covalent organic frameworks (Fe 3 O 4 @COFs) were synthesized via a facile approach at room temperature. Combining the advantages of high porosity, magnetic responsiveness, chemical stability and selectivity, Fe 3 O 4 @COFs can serve as an ideal absorbent for the highly efficient enrichment of peptides and the simultaneous exclusion of proteins from complex biological samples.

  4. Evaluation of "credit card" libraries for inhibition of HIV-1 gp41 fusogenic core formation.

    Science.gov (United States)

    Xu, Yang; Lu, Hong; Kennedy, Jack P; Yan, Xuxia; McAllister, Laura A; Yamamoto, Noboru; Moss, Jason A; Boldt, Grant E; Jiang, Shibo; Janda, Kim D

    2006-01-01

    Protein-protein interactions are of critical importance in biological systems, and small molecule modulators of such protein recognition and intervention processes are of particular interest. To investigate this area of research, we have synthesized small-molecule libraries that can disrupt a number of biologically relevant protein-protein interactions. These library members are designed upon planar motif, appended with a variety of chemical functions, which we have termed "credit-card" structures. From two of our "credit-card" libraries, a series of molecules were uncovered which act as inhibitors against the HIV-1 gp41 fusogenic 6-helix bundle core formation, viral antigen p24 formation, and cell-cell fusion at low micromolar concentrations. From the high-throughput screening assays we utilized, a selective index (SI) value of 4.2 was uncovered for compound 2261, which bodes well for future structure activity investigations and the design of more potent gp41 inhibitors.

  5. In vitro assembly into virus-like particles is an intrinsic quality of Pichia pastoris derived HCV core protein

    International Nuclear Information System (INIS)

    Acosta-Rivero, Nelson; Rodriguez, Armando; Musacchio, Alexis; Falcon, Viviana; Suarez, Viana M.; Martinez, Gillian; Guerra, Ivis; Paz-Lago, Dalila; Morera, Yanelys; Rosa, Maria C. de la; Morales-Grillo, Juan; Duenas-Carrera, Santiago

    2004-01-01

    Different variants of hepatitis C virus core protein (HCcAg) have proved to self-assemble in vitro into virus-like particles (VLPs). However, difficulties in obtaining purified mature HCcAg have limited these studies. In this study, a high degree of monomeric HCcAg purification was accomplished using chromatographic procedures under denaturing conditions. Size exclusion chromatography and sucrose density gradient centrifugation of renatured HCcAg (in the absence of structured RNA) under reducing conditions suggested that it assembled into empty capsids. The electron microscopy analysis of renatured HCcAg showed the presence of spherical VLPs with irregular shapes and an average diameter of 35 nm. Data indicated that HCcAg monomers assembled in vitro into VLPs in the absence of structured RNA, suggesting that recombinant HCcAg used in this work contains all the information necessary for the assembly process. However, they also suggest that some cellular factors might be required for the proper in vitro assembly of capsids

  6. C-Terminal Substitution of HBV Core Proteins with Those from DHBV Reveals That Arginine-Rich 167RRRSQSPRR175 Domain Is Critical for HBV Replication

    Science.gov (United States)

    Kim, Taeyeung; Shin, Bo-Hye; Park, Gil-Soon; Park, Sun; Chwae, Yong-Joon; Shin, Ho-Joon; Kim, Kyongmin

    2012-01-01

    To investigate the contributions of carboxyl-terminal nucleic acid binding domain of HBV core (C) protein for hepatitis B virus (HBV) replication, chimeric HBV C proteins were generated by substituting varying lengths of the carboxyl-terminus of duck hepatitis B virus (DHBV) C protein for the corresponding regions of HBV C protein. All chimeric C proteins formed core particles. A chimeric C protein with 221–262 amino acids of DHBV C protein, in place of 146–185 amino acids of the HBV C protein, supported HBV pregenomic RNA (pgRNA) encapsidation and DNA synthesis: 40% amino acid sequence identity or 45% homology in the nucleic-acid binding domain of HBV C protein was sufficient for pgRNA encapsidation and DNA synthesis, although we predominantly detected spliced DNA. A chimeric C protein with 221–241 and 251–262 amino acids of DHBV C, in place of HBV C 146–166 and 176–185 amino acids, respectively, could rescue full-length DNA synthesis. However, a reciprocal C chimera with 242–250 of DHBV C (242RAGSPLPRS 250) introduced in place of 167–175 of HBV C (167RRRSQSPRR 175) significantly decreased pgRNA encapsidation and DNA synthesis, and full-length DNA was not detected, demonstrating that the arginine-rich 167RRRSQSPRR175 domain may be critical for efficient viral replication. Five amino acids differing between viral species (underlined above) were tested for replication rescue; R169 and R175 were found to be important. PMID:22911745

  7. Highly efficient enrichment of low-abundance intact proteins by core-shell structured Fe3O4-chitosan@graphene composites.

    Science.gov (United States)

    Zhang, Peng; Fang, Xiaoni; Yan, Guoquan; Gao, Mingxia; Zhang, Xiangmin

    2017-11-01

    In proteomics research, the screening and monitoring of disease biomarkers is still a major challenge, mainly due to their low concentration in biological samples. However, the universal enrichment of intact proteins has not been further studied. In this work, we developed a Fe 3 O 4 -chitosan@graphene (Fe 3 O 4 -CS@G) core-shell composite to enrich low-abundance proteins from biological samples. Fe 3 O 4 -CS@G composite holds chitosan layer decorated Fe 3 O 4 core, which improves the hydrophilicity of materials greatly. Meanwhile, the graphene nanosheets shell formed via electrostatic assembly endows the composite with huge surface area (178m 2 /g). The good water dispersibility ensures the sufficient contact opportunities between graphene composites and proteins, and the large surface area provides enough adsorption sites for the enrichment of proteins. Using Fe 3 O 4 -CS@G, four standard proteins Cyt-c, BSA, Myo and OVA were enriched with better adsorption capacity and recovery rate, compared with previously reported magnetic graphene composites. Additionally, the mechanism of compared to" is corrected into "compared with". proteins adsorption on Fe 3 O 4 -CS@G was further studied, which indicates that hydrophobic and electrostatic interaction work together to facilitate the universal and efficient enrichment of proteins. Human plasma sample was employed to further evaluate the enrichment performance of Fe 3 O 4 -CS@G. Eventually, 123 proteins were identified from one of SAX fractions of human plasma, which is much better than commercial Sep-pak C18 enrichment column (39 proteins). All these outstanding performances suggest that Fe 3 O 4 -CS@G is an ideal platform for the enrichment of low-abundance intact proteins and thus holds great potential to facilitate the identification of biomarkers from biological samples in proteomics research. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Continuous production of core-shell protein nanoparticles by antisolvent precipitation using dual-channel microfluidization: Caseinate-coated zein nanoparticles.

    Science.gov (United States)

    Ebert, Sandra; Koo, Charmaine K W; Weiss, Jochen; McClements, David Julian

    2017-02-01

    Antisolvent precipitation is commonly used to fabricate protein nanoparticles using a simple batch method that involves injecting a protein-solvent mixture into an antisolvent. In this study, the potential of producing core-shell protein nanoparticles by antisolvent precipitation using a continuous dual-channel microfluidization method was investigated. The solvent phase (zein in ethanol) and antisolvent phase (casein in water) were made to impinge on each other at high velocity, which generates intense shear, turbulent, and cavitation forces that ensure thorough mixing and breakup of the phases. Relatively small core-shell protein nanoparticles (dnanoparticles went from positive at low pH to negative at high pH, with a point of zero charge around pH5. Electron microscopy indicated that the protein particles formed had a roughly spherical shape. The results suggest that the dual-channel microfluidizer could be used to continuously form protein nanoparticles by antisolvent precipitation. Nevertheless, when the microfluidization method was compared with the simple batch method the size of the particles produced under similar conditions were fairly similar. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Mesitylene-Cored Glucoside Amphiphiles (MGAs) for Membrane Protein Studies: Importance of Alkyl Chain Density in Detergent Efficacy

    DEFF Research Database (Denmark)

    Cho, Kyung Ho; Ribeiro, Orquidea; Du, Yang

    2016-01-01

    Detergents serve as useful tools for membrane protein structural and functional studies. Their amphipathic nature allows detergents to associate with the hydrophobic regions of membrane proteins whilst maintaining the proteins in aqueous solution. However, widely used conventional detergents...

  10. Hepatitis C virus core protein induces dysfunction of liver sinusoidal endothelial cell by down-regulation of silent information regulator 1.

    Science.gov (United States)

    Sun, Li-Jie; Yu, Jian-Wu; Shi, Yu-Guang; Zhang, Xiao-Yu; Shu, Meng-Ni; Chen, Mo-Yang

    2018-05-01

    Hepatic fibrosis is a frequent feature of chronic hepatitis C virus (HCV) infection. Some evidence has suggested the potential role of silent information regulator 1 (SIRT1) in organ fibrosis. The aim of this study was to investigate the effect of HCV core protein on expression of SIRT1 of liver sinusoidal endothelial cell (LSEC) and function of LSEC. LSECs were co-cultured with HepG2 cells or HepG2 cells expressing HCV core protein and LSECs cultured alone were used as controls. After co-culture, the activity and expression levels of mRNA and protein of SIRT1 in LSEC were detected by a SIRT1 fluorometric assay kit, real time-PCR (RT-PCR), Western blot, respectively. The levels of adiponectin receptor 2 (AdipoR2), endothelial nitric oxide synthase (eNOS) and vascular endothelial growth factor (VEGF) were measured by Western blot. Cluster of differentiation 31 (CD31), CD14, and von Willebrand factor (vWf) of LSECs was performed by flow cytometry. The level of reactive oxygen species (ROS) was assayed. Malondialdehyde (MDA), superoxide dismutase (SOD), adiponectin, nitric oxide (NO), and endothelin-1 (ET-1) levels in the co-culture supernatant were measured. The co-culture supernatant was then used to cultivate LX-2 cells. The levels of α-smooth muscle actin (ASMA) and transforming growth factor-β1 (TGF-β1) protein in LX-2 cells were measured by Western blot. Compared with LSEC co-cultured with HepG2 cells group, in LSEC co-cultured with HepG2-core cells group, the activity and expression level of mRNA and protein of SIRT1 reduced; the level of adiponectin reduced and the expression level of AdipoR2 protein decreased; ROS levels increased; the expression level of eNOS, VEGF protein decreased; and the expression level of CD14 decreased; the expression level of vWf and CD31 increased; NO and SOD levels decreased; whereas ET-1 and MDA levels increased; the levels of ASMA and TGF-β1 protein in LX-2 cells increased. SIRT1 activator improved the above-mentioned changes

  11. cDNA cloning of the basement membrane chondroitin sulfate proteoglycan core protein, bamacan: a five domain structure including coiled-coil motifs

    DEFF Research Database (Denmark)

    Wu, R R; Couchman, J R

    1997-01-01

    Basement membranes contain several proteoglycans, and those bearing heparan sulfate glycosaminoglycans such as perlecan and agrin usually predominate. Most mammalian basement membranes also contain chondroitin sulfate, and a core protein, bamacan, has been partially characterized. We have now....... The protein sequence has low overall homology, apart from very small NH2- and COOH-terminal motifs. At the junctions between the distal globular domains and the coiled-coil regions lie glycosylation sites, with up to three N-linked oligosaccharides and probably three chondroitin chains. Three other Ser...

  12. Charge neutralization as the major factor for the assembly of nucleocapsid-like particles from C-terminal truncated hepatitis C virus core protein.

    Science.gov (United States)

    de Souza, Theo Luiz Ferraz; de Lima, Sheila Maria Barbosa; Braga, Vanessa L de Azevedo; Peabody, David S; Ferreira, Davis Fernandes; Bianconi, M Lucia; Gomes, Andre Marco de Oliveira; Silva, Jerson Lima; de Oliveira, Andréa Cheble

    2016-01-01

    Hepatitis C virus (HCV) core protein, in addition to its structural role to form the nucleocapsid assembly, plays a critical role in HCV pathogenesis by interfering in several cellular processes, including microRNA and mRNA homeostasis. The C-terminal truncated HCV core protein (C124) is intrinsically unstructured in solution and is able to interact with unspecific nucleic acids, in the micromolar range, and to assemble into nucleocapsid-like particles (NLPs) in vitro . The specificity and propensity of C124 to the assembly and its implications on HCV pathogenesis are not well understood. Spectroscopic techniques, transmission electron microscopy and calorimetry were used to better understand the propensity of C124 to fold or to multimerize into NLPs when subjected to different conditions or in the presence of unspecific nucleic acids of equivalent size to cellular microRNAs. The structural analysis indicated that C124 has low propensity to self-folding. On the other hand, for the first time, we show that C124, in the absence of nucleic acids, multimerizes into empty NLPs when subjected to a pH close to its isoelectric point (pH ≈ 12), indicating that assembly is mainly driven by charge neutralization. Isothermal calorimetry data showed that the assembly of NLPs promoted by nucleic acids is enthalpy driven. Additionally, data obtained from fluorescence correlation spectroscopy show that C124, in nanomolar range, was able to interact and to sequester a large number of short unspecific nucleic acids into NLPs. Together, our data showed that the charge neutralization is the major factor for the nucleocapsid-like particles assembly from C-terminal truncated HCV core protein. This finding suggests that HCV core protein may physically interact with unspecific cellular polyanions, which may correspond to microRNAs and mRNAs in a host cell infected by HCV, triggering their confinement into infectious particles.

  13. Charge neutralization as the major factor for the assembly of nucleocapsid-like particles from C-terminal truncated hepatitis C virus core protein

    Directory of Open Access Journals (Sweden)

    Theo Luiz Ferraz de Souza

    2016-11-01

    Full Text Available Background Hepatitis C virus (HCV core protein, in addition to its structural role to form the nucleocapsid assembly, plays a critical role in HCV pathogenesis by interfering in several cellular processes, including microRNA and mRNA homeostasis. The C-terminal truncated HCV core protein (C124 is intrinsically unstructured in solution and is able to interact with unspecific nucleic acids, in the micromolar range, and to assemble into nucleocapsid-like particles (NLPs in vitro. The specificity and propensity of C124 to the assembly and its implications on HCV pathogenesis are not well understood. Methods Spectroscopic techniques, transmission electron microscopy and calorimetry were used to better understand the propensity of C124 to fold or to multimerize into NLPs when subjected to different conditions or in the presence of unspecific nucleic acids of equivalent size to cellular microRNAs. Results The structural analysis indicated that C124 has low propensity to self-folding. On the other hand, for the first time, we show that C124, in the absence of nucleic acids, multimerizes into empty NLPs when subjected to a pH close to its isoelectric point (pH ≈ 12, indicating that assembly is mainly driven by charge neutralization. Isothermal calorimetry data showed that the assembly of NLPs promoted by nucleic acids is enthalpy driven. Additionally, data obtained from fluorescence correlation spectroscopy show that C124, in nanomolar range, was able to interact and to sequester a large number of short unspecific nucleic acids into NLPs. Discussion Together, our data showed that the charge neutralization is the major factor for the nucleocapsid-like particles assembly from C-terminal truncated HCV core protein. This finding suggests that HCV core protein may physically interact with unspecific cellular polyanions, which may correspond to microRNAs and mRNAs in a host cell infected by HCV, triggering their confinement into infectious particles.

  14. Expression, purification, crystallization and preliminary X-ray crystallographic studies of hepatitis B virus core fusion protein corresponding to octahedral particles

    International Nuclear Information System (INIS)

    Kikuchi, Masaki; Iwabuchi, Shinichiro; Kikkou, Tatsuhiko; Noguchi, Keiichi; Odaka, Masafumi; Yohda, Masafumi; Kawata, Masaaki; Sato, Chikara; Matsumoto, Osamu

    2013-01-01

    Novel hepatitis B virus-like particles of recombinant dimeric core–GFP fusion protein were expressed, purified and crystallized. The crystals diffracted to 2.15 Å resolution and belonged to space group F432, with unit-cell parameters a = b = c = 219.7 Å. Recombinant hepatitis B virus core proteins dimerize to form building blocks that are capable of self-assembly into a capsid. A core capsid protein dimer (CPD) linked to a green fluorescent protein variant, EGFP, at the C-terminus has been designed. The recombinant fusion CPD was expressed in Escherichia coli, assembled into virus-like particles (VLPs), purified and crystallized. The single crystal diffracted to 2.15 Å resolution and belonged to the cubic space group F432, with unit-cell parameters a = b = c = 219.7 Å. The fusion proteins assembled into icosahedral VLPs in aqueous solution, but were rearranged into octahedral symmetry through the crystal-packing process under the crystallization conditions

  15. A Panel of Recombinant Mucins Carrying a Repertoire of Sialylated O-Glycans Based on Different Core Chains for Studies of Glycan Binding Proteins

    Directory of Open Access Journals (Sweden)

    Reeja Maria Cherian

    2015-08-01

    Full Text Available Sialylated glycans serve as key elements of receptors for many viruses, bacteria, and bacterial toxins. The microbial recognition and their binding specificity can be affected by the linkage of the terminal sugar residue, types of underlying sugar chains, and the nature of the entire glycoconjugate. Owing to the pathobiological significance of sialylated glycans, we have engineered Chinese hamster ovary (CHO cells to secrete mucin-type immunoglobulin-fused proteins carrying terminal α2,3- or α2,6-linked sialic acid on defined O-glycan core saccharide chains. Besides stably expressing P-selectin glycoprotein ligand-1/mouse immunoglobulin G2b cDNA (PSGL-1/mIgG2b, CHO cells were stably transfected with plasmids encoding glycosyltransferases to synthesize core 2 (GCNT1, core 3 (B3GNT6, core 4 (GCNT1 and B3GNT6, or extended core 1 (B3GNT3 chains with or without the type 1 chain-encoding enzyme B3GALT5 and ST6GAL1. Western blot and liquid chromatography-mass spectrometry analysis confirmed the presence of core 1, 2, 3, 4, and extended core 1 chains carrying either type 1 (Galb3GlcNAc or type 2 (Galb4GlcNAc outer chains with or without α2,6-linked sialic acids. This panel of recombinant mucins carrying a repertoire of sialylated O-glycans will be important tools in studies aiming at determining the fine O-glycan binding specificity of sialic acid-specific microbial adhesins and mammalian lectins.

  16. Identification of a novel antimicrobial peptide from human hepatitis B virus core protein arginine-rich domain (ARD.

    Directory of Open Access Journals (Sweden)

    Heng-Li Chen

    Full Text Available The rise of multidrug-resistant (MDR pathogens causes an increasing challenge to public health. Antimicrobial peptides are considered a possible solution to this problem. HBV core protein (HBc contains an arginine-rich domain (ARD at its C-terminus, which consists of 16 arginine residues separated into four clusters (ARD I to IV. In this study, we demonstrated that the peptide containing the full-length ARD I-IV (HBc147-183 has a broad-spectrum antimicrobial activity at micro-molar concentrations, including some MDR and colistin (polymyxin E-resistant Acinetobacter baumannii. Furthermore, confocal fluorescence microscopy and SYTOX Green uptake assay indicated that this peptide killed Gram-negative and Gram-positive bacteria by membrane permeabilization or DNA binding. In addition, peptide ARD II-IV (HBc153-176 and ARD I-III (HBc147-167 were found to be necessary and sufficient for the activity against P. aeruginosa and K. peumoniae. The antimicrobial activity of HBc ARD peptides can be attenuated by the addition of LPS. HBc ARD peptide was shown to be capable of direct binding to the Lipid A of lipopolysaccharide (LPS in several in vitro binding assays. Peptide ARD I-IV (HBc147-183 had no detectable cytotoxicity in various tissue culture systems and a mouse animal model. In the mouse model by intraperitoneal (i.p. inoculation with Staphylococcus aureus, timely treatment by i.p. injection with ARD peptide resulted in 100-fold reduction of bacteria load in blood, liver and spleen, as well as 100% protection of inoculated animals from death. If peptide was injected when bacterial load in the blood reached its peak, the protection rate dropped to 40%. Similar results were observed in K. peumoniae using an IVIS imaging system. The finding of anti-microbial HBc ARD is discussed in the context of commensal gut microbiota, development of intrahepatic anti-viral immunity and establishment of chronic infection with HBV. Our current results suggested that

  17. CD4 lymphocyte counts and serum p24 antigen of no diagnostic value in monitoring HIV-infected patients with pulmonary symptoms

    DEFF Research Database (Denmark)

    Orholm, M; Nielsen, T L; Nielsen, Jens Ole

    1990-01-01

    The diagnostic value of the CD4 cell counts and the HIV p24 antigen were evaluated in a consecutive series of 105 HIV-infected patients experiencing 128 episodes of pulmonary symptoms which required bronchoscopy. One-third of patients with opportunistic infection (OI) had CD4 counts greater than ....... In conclusion, the CD4 cell counts and the presence of p24 antigen in serum had a very limited predictive value for the presence of OI in HIV-infected patients with pulmonary symptoms.......The diagnostic value of the CD4 cell counts and the HIV p24 antigen were evaluated in a consecutive series of 105 HIV-infected patients experiencing 128 episodes of pulmonary symptoms which required bronchoscopy. One-third of patients with opportunistic infection (OI) had CD4 counts greater than 0.......200 x 10(9)/l, and 60% of patients without OI had CD4 counts less than 0.200 x 10(9)/l; 47 and 42% of patients with and without OI, respectively, had detectable p24 antigen in serum. Only 36% of the patients with OI presented the combination of CD4 cells less than 0.200 x 10(9)/l and p24 in serum...

  18. Downregulation of miRNA-30c and miR-203a is associated with hepatitis C virus core protein-induced epithelial–mesenchymal transition in normal hepatocytes and hepatocellular carcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Dongjing [Hepatobiliary and Enteric Surgery Research Center, Xiangya Hospital, Central South University, Changsha 410008 (China); Wu, Jilin, E-mail: 6296082@qq.com [Hepatobiliary and Enteric Surgery Research Center, Xiangya Hospital, Central South University, Changsha 410008 (China); Liu, Meizhou [Department of Medical Service, Shenzhen Second People' s Hospital, Shenzhen, Guangdong 518035 (China); Yin, Hui [Staff' s Hospital, Central South University, Changsha, Hunan 410078 (China); He, Jiantai [Hepatobiliary and Enteric Surgery Research Center, Xiangya Hospital, Central South University, Changsha 410008 (China); Zhang, Bo, E-mail: zhangbo8095@126.com [Department of Ultrasonography, Xiangya Hospital, Central South University, Changsha, Hunan 410008 (China)

    2015-09-04

    Hepatitis C virus (HCV) Core protein has been demonstrated to induce epithelial–mesenchymal transition (EMT) and is associated with cancer progression of hepatocellular carcinoma (HCC). However, how the Core protein regulates EMT is still unclear. In this study, HCV Core protein was overexpressed by an adenovirus. The protein levels of EMT markers were measured by Western blot. The xenograft animal model was established by inoculation of HepG2 cells. Results showed that ectopic expression of HCV core protein induced EMT in L02 hepatocytes and HepG2 tumor cells by upregulating vimentin, Sanl1, and Snal2 expression and downregulating E-cadherin expression. Moreover, Core protein downregulated miR-30c and miR-203a levels in L02 and HepG2 cells, but artificial expression of miR-30c and miR-203a reversed Core protein-induced EMT. Further analysis showed that ectopic expression of HCV core protein stimulated cell proliferation, inhibited apoptosis, and increased cell migration, whereas artificial expression of miR-30c and miR-203a significantly reversed the role of Core protein in these cell functions in L02 and HepG2 cells. In the HepG2 xenograft tumor models, artificial expression of miR-30c and miR-203a inhibited EMT and tumor growth. Moreover, L02 cells overexpressing Core protein can form tumors in nude mice. In HCC patients, HCV infection significantly shortened patients' survival time, and loss of miR-30c and miR-203 expression correlated with poor survival. In conclusion, HCV core protein downregulates miR-30c and miR-203a expression, which results in activation of EMT in normal hepatocytes and HCC tumor cells. The Core protein-activated-EMT is involved in the carcinogenesis and progression of HCC. Loss of miR-30c and miR-203a expression is a marker for the poor prognosis of HCC. - Highlights: • HCV core protein downregulates miR-30c and miR-203a expression. • Downregulation of miR-30c and miR-203a activates EMT. • Activated-EMT is involved in the

  19. Evaluation of “Credit Card” Libraries for Inhibition of HIV-1 gp41 Fusogenic Core Formation

    Science.gov (United States)

    Xu, Yang; Lu, Hong; Kennedy, Jack P.; Yan, Xuxia; McAllister, Laura; Yamamoto, Noboru; Moss, Jason A.; Boldt, Grant E.; Jiang, Shibo; Janda, Kim D.

    2008-01-01

    Protein-protein interactions are of critical importance in biological systems and small molecule modulators of such protein recognition and intervention processes are of particular interests. To investigate this area of research, we have synthesized small molecule libraries that can disrupt a number of biologically relevant protein-protein interactions. These library members are designed upon planar motifs, appended with a variety of chemical functions, which we have termed as “credit-card” structures. From two of our “credit-card” libraries, a series of molecules were uncovered which act as inhibitors against the HIV-1 gp41 fusogenic 6-helix bundle core formation, viral antigen p24 formation and cell-cell fusion at low micromolar concentrations. From the high-throughput screening assays we utilized, a selective index (SI) value of 4.2 was uncovered for compound 2261, which bodes well for future structure activity investigations and the design of more potent gp41 inhibitors. PMID:16827565

  20. Electrostatic Architecture of the Infectious Salmon Anemia Virus (ISAV) Core Fusion Protein Illustrates a Carboxyl-Carboxylate pH Sensor.

    Science.gov (United States)

    Cook, Jonathan D; Soto-Montoya, Hazel; Korpela, Markus K; Lee, Jeffrey E

    2015-07-24

    Segment 5, ORF 1 of the infectious salmon anemia virus (ISAV) genome, encodes for the ISAV F protein, which is responsible for viral-host endosomal membrane fusion during a productive ISAV infection. The entry machinery of ISAV is composed of a complex of the ISAV F and ISAV hemagglutinin esterase (HE) proteins in an unknown stoichiometry prior to receptor engagement by ISAV HE. Following binding of the receptor to ISAV HE, dissociation of the ISAV F protein from HE, and subsequent endocytosis, the ISAV F protein resolves into a fusion-competent oligomeric state. Here, we present a 2.1 Å crystal structure of the fusion core of the ISAV F protein determined at low pH. This structure has allowed us to unambiguously demonstrate that the ISAV entry machinery exhibits typical class I viral fusion protein architecture. Furthermore, we have determined stabilizing factors that accommodate the pH-dependent mode of ISAV transmission, and our structure has allowed the identification of a central coil that is conserved across numerous and varied post-fusion viral glycoprotein structures. We then discuss a mechanistic model of ISAV fusion that parallels the paramyxoviral class I fusion strategy wherein attachment and fusion are relegated to separate proteins in a similar fashion to ISAV fusion. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  1. CD4+ Primary T Cells Expressing HCV-Core Protein Upregulate Foxp3 and IL-10, Suppressing CD4 and CD8 T Cells

    Science.gov (United States)

    Aguado, Enrique; Garcia-Cozar, Francisco

    2014-01-01

    Adaptive T cell responses are critical for controlling HCV infection. While there is clinical evidence of a relevant role for regulatory T cells in chronic HCV-infected patients, based on their increased number and function; mechanisms underlying such a phenomena are still poorly understood. Accumulating evidence suggests that proteins from Hepatitis C virus can suppress host immune responses. We and others have shown that HCV is present in CD4+ lymphocytes from chronically infected patients and that HCV-core protein induces a state of unresponsiveness in the CD4+ tumor cell line Jurkat. Here we show that CD4+ primary T cells lentivirally transduced with HCV-core, not only acquire an anergic phenotype but also inhibit IL-2 production and proliferation of bystander CD4+ or CD8+ T cells in response to anti-CD3 plus anti-CD28 stimulation. Core-transduced CD4+ T cells show a phenotype characterized by an increased basal secretion of the regulatory cytokine IL-10, a decreased IFN-γ production upon stimulation, as well as expression of regulatory T cell markers, CTLA-4, and Foxp3. A significant induction of CD4+CD25+CD127lowPD-1highTIM-3high regulatory T cells with an exhausted phenotype was also observed. Moreover, CCR7 expression decreased in HCV-core expressing CD4+ T cells explaining their sequestration in inflamed tissues such as the infected liver. This work provides a new perspective on de novo generation of regulatory CD4+ T cells in the periphery, induced by the expression of a single viral protein. PMID:24465502

  2. CD4+ primary T cells expressing HCV-core protein upregulate Foxp3 and IL-10, suppressing CD4 and CD8 T cells.

    Directory of Open Access Journals (Sweden)

    Cecilia Fernandez-Ponce

    Full Text Available Adaptive T cell responses are critical for controlling HCV infection. While there is clinical evidence of a relevant role for regulatory T cells in chronic HCV-infected patients, based on their increased number and function; mechanisms underlying such a phenomena are still poorly understood. Accumulating evidence suggests that proteins from Hepatitis C virus can suppress host immune responses. We and others have shown that HCV is present in CD4+ lymphocytes from chronically infected patients and that HCV-core protein induces a state of unresponsiveness in the CD4+ tumor cell line Jurkat. Here we show that CD4+ primary T cells lentivirally transduced with HCV-core, not only acquire an anergic phenotype but also inhibit IL-2 production and proliferation of bystander CD4+ or CD8+ T cells in response to anti-CD3 plus anti-CD28 stimulation. Core-transduced CD4+ T cells show a phenotype characterized by an increased basal secretion of the regulatory cytokine IL-10, a decreased IFN-γ production upon stimulation, as well as expression of regulatory T cell markers, CTLA-4, and Foxp3. A significant induction of CD4+CD25+CD127(lowPD-1(highTIM-3(high regulatory T cells with an exhausted phenotype was also observed. Moreover, CCR7 expression decreased in HCV-core expressing CD4+ T cells explaining their sequestration in inflamed tissues such as the infected liver. This work provides a new perspective on de novo generation of regulatory CD4+ T cells in the periphery, induced by the expression of a single viral protein.

  3. High mobility group protein number17 cross-links primarily to histone H2A in the reconstituted HMG 17 - nucleosome core particle complex

    International Nuclear Information System (INIS)

    Cook, G.R.; Yau, P.; Yasuda, H.; Traut, R.R.; Bradbury, E.M.

    1986-01-01

    The neighbor relationship of lamb thymus High Mobility Group (HMG) protein 17 to native HeLa nucleosome core particle histones in the reconstituted complex has been studied. 125 I-labeled HMG 17 was cross-linking to core histones using the protein-protein cross-linking reagent 2-iminothiolane. Specific cross-linked products were separated on a two-dimensional Triton-acid-urea/SDS gel system, located by autoradiography, excised and quantified. Disulfide bonds in the cross links were then cleaved and the protein constituents were identified by SDS gel electrophoresis. HMG 17 cross-linked primarily to histone H2A while lower levels of cross-linking occurred between HMG 17 and the other histones. In contrast, cross-linking between two HMG 17 molecules bound on the same nucleosome was relatively rare. It is concluded that the same nucleosome was relatively rare. It is concluded that H2A comprises part of the HMG 17 binding site but that HMG 17 is sufficiently elongated and mobile to permit cross-linking to the other histones and to a second HMG 17 molecule. These results are in agreement with the current model for the structure of the nucleosome and the proposed binding sites for HMG 17

  4. Heat, hydrogen peroxide, and UV resistance of Bacillus subtilis spores with increased core water content and with or without major DNA-binding proteins

    International Nuclear Information System (INIS)

    Popham, D.L.; Sengupta, S.; Setlow, P.

    1995-01-01

    Spores of a Bacillus subtilis strain with an insertion mutation in the dacB gene, which codes for an enzyme involved in spore cortex biosynthesis, have a higher core water content than wild-type spores. Spores lacking the two major α/β-type small, acid-soluble proteins (SASP) (termed a α - β - spores) have the same core water content as do wild-type spores, but α - β - dacB spores had more core water than did dacB spores. The resistance of α - β - , α - β - dacB, dacB, and wild-type spores to dry and moist heat, hydrogen peroxide, and UV radiation has been determined, as has the role of DNA damage in spore killing by moist heat and hydrogen peroxide. These data (1) suggest that core water content has little if any role in spore UV resistance and are consistent with binding of α/β-type SASP to DNA being the major mechanism providing protection to spores from UV radiation; (2) suggest that binding of αβ-type SASP to DNA is the major mechanism unique to spores providing protection from dry heat; (3) suggest that spore resistance to moist heat and hydrogen peroxide is affected to a large degree by the core water content, as increased core water resulted in large decreases in spore resistance to these agents; and (4) indicate that since this decreased resistance (i.e., in dacB spores) is not associated with increased spore killing by DNA damage, spore DNA must normally be extremely well protected against such damage, presumably by the saturation of spore DNA by α/β-type SASP. 19 refs., 2 figs., 5 tabs

  5. CD4 lymphocyte counts and serum p24 antigen of no diagnostic value in monitoring HIV-infected patients with pulmonary symptoms

    DEFF Research Database (Denmark)

    Orholm, M; Nielsen, T L; Nielsen, Jens Ole

    1990-01-01

    The diagnostic value of the CD4 cell counts and the HIV p24 antigen were evaluated in a consecutive series of 105 HIV-infected patients experiencing 128 episodes of pulmonary symptoms which required bronchoscopy. One-third of patients with opportunistic infection (OI) had CD4 counts greater than 0....... In conclusion, the CD4 cell counts and the presence of p24 antigen in serum had a very limited predictive value for the presence of OI in HIV-infected patients with pulmonary symptoms....

  6. The effect of treatment with zidovudine with or without acyclovir on HIV p24 antigenaemia in patients with AIDS or AIDS-related complex

    DEFF Research Database (Denmark)

    Pedersen, C; Cooper, D A; Brun-Vézinet, F

    1992-01-01

    with AIDS, AIDS-related complex (ARC) or Kaposi's sarcoma (KS). DESIGN: Double-blind, placebo-controlled randomized clinical trial of less than or equal to 6 months' therapy. SETTING: Samples were obtained from patients attending teaching hospital outpatient clinics in seven European countries and Australia....... SUBJECTS: One hundred and ninety-seven HIV-infected patients (60 with AIDS and 137 with ARC or KS). MAIN OUTCOME MEASURES: Serum HIV p24-antigen levels measured using the Abbott HIV solid-phase enzyme immunoassay. RESULTS: Of 76 ARC/KS patients who were initially HIV p24-antigen-positive, one out of 25...

  7. The crystal structure of the core domain of a cellulose induced protein (Cip1 from Hypocrea jecorina, at 1.5 Å resolution.

    Directory of Open Access Journals (Sweden)

    Frida Jacobson

    Full Text Available In an effort to characterise the whole transcriptome of the fungus Hypocrea jecorina, cDNA clones of this fungus were identified that encode for previously unknown proteins that are likely to function in biomass degradation. One of these newly identified proteins, found to be co-regulated with the major H. jecorina cellulases, is a protein that was denoted Cellulose induced protein 1 (Cip1. This protein consists of a glycoside hydrolase family 1 carbohydrate binding module connected via a linker region to a domain with yet unknown function. After cloning and expression of Cip1 in H. jecorina, the protein was purified and biochemically characterised with the aim of determining a potential enzymatic activity for the novel protein. No hydrolytic activity against any of the tested plant cell wall components was found. The proteolytic core domain of Cip1 was then crystallised, and the three-dimensional structure of this was determined to 1.5 Å resolution utilising sulphur single-wavelength anomalous dispersion phasing (sulphor-SAD. A calcium ion binding site was identified in a sequence conserved region of Cip1 and is also seen in other proteins with the same general fold as Cip1, such as many carbohydrate binding modules. The presence of this ion was found to have a structural role. The Cip1 structure was analysed and a structural homology search was performed to identify structurally related proteins. The two published structures with highest overall structural similarity to Cip1 found were two poly-lyases: CsGL, a glucuronan lyase from H. jecorina and vAL-1, an alginate lyase from the Chlorella virus. This indicates that Cip1 may be a lyase. However, initial trials did not detect significant lyase activity for Cip1. Cip1 is the first structure to be solved of the 23 currently known Cip1 sequential homologs (with a sequence identity cut-off of 25%, including both bacterial and fungal members.

  8. Colloidal Gold--Collagen Protein Core--Shell Nanoconjugate: One-Step Biomimetic Synthesis, Layer-by-Layer Assembled Film, and Controlled Cell Growth.

    Science.gov (United States)

    Xing, Ruirui; Jiao, Tifeng; Yan, Linyin; Ma, Guanghui; Liu, Lei; Dai, Luru; Li, Junbai; Möhwald, Helmuth; Yan, Xuehai

    2015-11-11

    The biogenic synthesis of biomolecule-gold nanoconjugates is of key importance for a broad range of biomedical applications. In this work, a one-step, green, and condition-gentle strategy is presented to synthesize stable colloidal gold-collagen core-shell nanoconjugates in an aqueous solution at room temperature, without use of any reducing agents and stabilizing agents. It is discovered that electrostatic binding between gold ions and collagen proteins and concomitant in situ reduction by hydroxyproline residues are critically responsible for the formation of the core-shell nanoconjugates. The film formed by layer-by-layer assembly of such colloidal gold-collagen nanoconjugates can notably improve the mechanical properties and promote cell adhesion, growth, and differentiation. Thus, the colloidal gold-collagen nanoconjugates synthesized by such a straightforward and clean manner, analogous to a biomineralization pathway, provide new alternatives for developing biologically based hybrid biomaterials toward a range of therapeutic and diagnostic applications.

  9. The biodistribution and pretargeting radioimmunoimaging of the fusion protein of anti-CEA single-chain antibody and core-streptavidin in human rectocolonic tumor bearing nude mice

    International Nuclear Information System (INIS)

    Yang Weidong; Li Biao; Zhu Chengmo; Jiang Xufeng; Feng Guowei; Wu Xiangpu

    2002-01-01

    Objective: To investigate the biodistribution and two-step pretargeting radioimmunoimaging of the fusion protein of anti-carcinoembryonic antigen (CEA) single-chain antibody (ScFv) and core-streptavidin in human rectocolonic tumor bearing nude mice. Methods: Before the injection of 153 Sm-biotin, the fusion protein of ScFv-core-streptavidin was pretargeted for 24 h (200 μg every nude mouse), 24 h later 153 Sm-biotin was injected. The uptake of radioactivity in tumor and normal tissues in 20 nude mice was measured at 1, 4, 8 and 24 h and the other 3 nude mice was scanned at 8 and 24 h after peritoneal injection of 153 Sm-biotin. Results: The tumor to blood ratio (tumor/blood) reached 0.49 , 1.21, 1.56 and 3.09 at 1, 4, 8 and 24 h respectively. Radioactivity concentration peaked at 8 h in tumor site and demonstrated a 'hot' area, with significant decreasing its background at 24 h. Conclusion: The fusion protein can elevate the tumor/blood ratio, shorten pretargeting and imaging process and also improve image quality

  10. A monoclonal antibody (SJ-9A4) to P24 present on common alls, neuroblastomas and platelets - I. Characterization and development of a unique radioimmunometric assay.

    Science.gov (United States)

    Komada, Y; Peiper, S C; Melvin, S L; Metzger, D W; Tarnowski, B H; Green, A A

    1983-01-01

    We report the development and characterization of SJ-9A4, a monoclonal antibody (MoAb) produced against common acute lymphoblastic leukemia (C-ALL) cell lines. SJ-9A4 reacted with C-ALL, B-cell chronic lymphocytic leukemia (B-CLL), platelets and C-ALL neuroblastoma (NB) and the K562 cell lines. It had no significant reactivity with erythrocytes, granulocytes, circulating T or B lymphocytes, monocytes, granulocytic cell lines or a Ewing's sarcoma cell line. SJ-9A4 was shown to recognize the same region as two other MoAb to the p24 antigen, BA-2 and DU-ALL-1, as demonstrated by their ability to inhibit the binding of labeled SJ-9A4 to NALM-1 and NB cells. Other MoAb: J5, PI 153/3 and monoclonal anti-HLA-DR antibodies gave no inhibition. A solid phase indirect radioimmunometric assay (IRA) was developed which enabled the detection of P24 from C-ALL cells, utilizing its ability to bind the Ricinus communis agglutinin (RCA1) or wheat germ agglutinin (WGA) and SJ-9A4 simultaneously. When BA-2 and DU-ALL-1 were used in place of SJ-9A4, similar IRA results were obtained. Using the RCA1/SJ-9A4-IRA, P24 from as few as 1.6 X 10(4) cells of a C-ALL cell line could be detected; however, similar extracts of NB cell lines were negative despite high levels of SJ-9A4 binding to intact cells. The presence of P24 in NB extracts was demonstrated by (1) preincubation of NB extracts with SJ-9A4 which blocked MoAb binding to P24 and (2) immunoadsorption of P24 from solubilized membranes of 35S-methionine (met) labeled NB cells. Treatment of NB cells with neuraminidase did not result in IRA binding when either RCA1 or WGA were used as the solid phase lectin indicating that the differences in lectin affinity are not due to over sialation of NB membrane glycoproteins. These findings demonstrate a difference in the glycosylation of P24 from C-ALL and NB cells.

  11. Structures of SRP54 and SRP19, the two proteins that organize the ribonucleic core of the signal recognition particle from Pyrococcus furiosus.

    Directory of Open Access Journals (Sweden)

    Pascal F Egea

    Full Text Available In all organisms the Signal Recognition Particle (SRP, binds to signal sequences of proteins destined for secretion or membrane insertion as they emerge from translating ribosomes. In Archaea and Eucarya, the conserved ribonucleoproteic core is composed of two proteins, the accessory protein SRP19, the essential GTPase SRP54, and an evolutionarily conserved and essential SRP RNA. Through the GTP-dependent interaction between the SRP and its cognate receptor SR, ribosomes harboring nascent polypeptidic chains destined for secretion are dynamically transferred to the protein translocation apparatus at the membrane. We present here high-resolution X-ray structures of SRP54 and SRP19, the two RNA binding components forming the core of the signal recognition particle from the hyper-thermophilic archaeon Pyrococcus furiosus (Pfu. The 2.5 A resolution structure of free Pfu-SRP54 is the first showing the complete domain organization of a GDP bound full-length SRP54 subunit. In its ras-like GTPase domain, GDP is found tightly associated with the protein. The flexible linker that separates the GTPase core from the hydrophobic signal sequence binding M domain, adopts a purely alpha-helical structure and acts as an articulated arm allowing the M domain to explore multiple regions as it scans for signal peptides as they emerge from the ribosomal tunnel. This linker is structurally coupled to the GTPase catalytic site and likely to propagate conformational changes occurring in the M domain through the SRP RNA upon signal sequence binding. Two different 1.8 A resolution crystal structures of free Pfu-SRP19 reveal a compact, rigid and well-folded protein even in absence of its obligate SRP RNA partner. Comparison with other SRP19*SRP RNA structures suggests the rearrangement of a disordered loop upon binding with the RNA through a reciprocal induced-fit mechanism and supports the idea that SRP19 acts as a molecular scaffold and a chaperone, assisting the SRP

  12. Genome Editing for Cancer Therapy: Delivery of Cas9 Protein/sgRNA Plasmid via a Gold Nanocluster/Lipid Core-Shell Nanocarrier.

    Science.gov (United States)

    Wang, Peng; Zhang, Lingmin; Xie, Yangzhouyun; Wang, Nuoxin; Tang, Rongbing; Zheng, Wenfu; Jiang, Xingyu

    2017-11-01

    The type II bacterial clustered, regularly interspaced, short palindromic repeats (CRISPR)-Cas9 (CRISPR-associated protein) system (CRISPR-Cas9) is a powerful toolbox for gene-editing, however, the nonviral delivery of CRISPR-Cas9 to cells or tissues remains a key challenge. This paper reports a strategy to deliver Cas9 protein and single guide RNA (sgRNA) plasmid by a nanocarrier with a core of gold nanoclusters (GNs) and a shell of lipids. By modifying the GNs with HIV-1-transactivator of transcription peptide, the cargo (Cas9/sgRNA) can be delivered into cell nuclei. This strategy is utilized to treat melanoma by designing sgRNA targeting Polo-like kinase-1 ( Plk1 ) of the tumor. The nanoparticle (polyethylene glycol-lipid/GNs/Cas9 protein/sgPlk1 plasmid, LGCP) leads to >70% down-regulation of Plk1 protein expression of A375 cells in vitro. Moreover, the LGCP suppresses melanoma progress by 75% on mice. Thus, this strategy can deliver protein-nucleic acid hybrid agents for gene therapy.

  13. ELISA for the core protein of the cartilage large aggregating proteoglycan, aggrecan: comparison with the concentrations of immunogenic keratan sulphate in synovial fluid, serum and urine

    DEFF Research Database (Denmark)

    Møller, H J; Larsen, F S; Ingemann-Hansen, T

    1994-01-01

    ELISA. The within-assay and between-assay coefficients of variation were 4.9-8.9% and 11.1-13.0%, respectively. The mean concentrations of core protein in synovial fluid, serum and urine were 76.4 micrograms/ml, 104.0 ng/ml and 81.0 ng/ml, respectively. In synovial fluids the concentrations were closely......Immunological assays for fragments of the cartilage large aggregating proteoglycan, aggrecan, have been widely used to monitor cartilage turnover. These assays have commonly employed the monoclonal keratan sulphate antibody, 5D4. Keratan sulphate, however, is present in many tissues and 5D4...

  14. Antibodies to the core proteins of Nairobi sheep disease virus/Ganjam virus reveal details of the distribution of the proteins in infected cells and tissues.

    Science.gov (United States)

    Lasecka, Lidia; Bin-Tarif, Abdelghani; Bridgen, Anne; Juleff, Nicholas; Waters, Ryan A; Baron, Michael D

    2015-01-01

    Nairobi sheep disease virus (NSDV; also called Ganjam virus in India) is a bunyavirus of the genus Nairovirus. It causes a haemorrhagic gastroenteritis in sheep and goats with mortality up to 90%. The virus is closely related to the human pathogen Crimean-Congo haemorrhagic fever virus (CCHFV). Little is currently known about the biology of NSDV. We have generated specific antibodies against the virus nucleocapsid protein (N) and polymerase (L) and used these to characterise NSDV in infected cells and to study its distribution during infection in a natural host. Due to its large size and the presence of a papain-like protease (the OTU-like domain) it has been suggested that the L protein of nairoviruses undergoes an autoproteolytic cleavage into polymerase and one or more accessory proteins. Specific antibodies which recognise either the N-terminus or the C-terminus of the NSDV L protein showed no evidence of L protein cleavage in NSDV-infected cells. Using the specific anti-N and anti-L antibodies, it was found that these viral proteins do not fully colocalise in infected cells; the N protein accumulated near the Golgi at early stages of infection while the L protein was distributed throughout the cytoplasm, further supporting the multifunctional nature of the L protein. These antibodies also allowed us to gain information about the organs and cell types targeted by the virus in vivo. We could detect NSDV in cryosections prepared from various tissues collected post-mortem from experimentally inoculated animals; the virus was found in the mucosal lining of the small and large intestine, in the lungs, and in mesenteric lymph nodes (MLN), where NSDV appeared to target monocytes and/or macrophages.

  15. Antibodies to the core proteins of Nairobi sheep disease virus/Ganjam virus reveal details of the distribution of the proteins in infected cells and tissues.

    Directory of Open Access Journals (Sweden)

    Lidia Lasecka

    Full Text Available Nairobi sheep disease virus (NSDV; also called Ganjam virus in India is a bunyavirus of the genus Nairovirus. It causes a haemorrhagic gastroenteritis in sheep and goats with mortality up to 90%. The virus is closely related to the human pathogen Crimean-Congo haemorrhagic fever virus (CCHFV. Little is currently known about the biology of NSDV. We have generated specific antibodies against the virus nucleocapsid protein (N and polymerase (L and used these to characterise NSDV in infected cells and to study its distribution during infection in a natural host. Due to its large size and the presence of a papain-like protease (the OTU-like domain it has been suggested that the L protein of nairoviruses undergoes an autoproteolytic cleavage into polymerase and one or more accessory proteins. Specific antibodies which recognise either the N-terminus or the C-terminus of the NSDV L protein showed no evidence of L protein cleavage in NSDV-infected cells. Using the specific anti-N and anti-L antibodies, it was found that these viral proteins do not fully colocalise in infected cells; the N protein accumulated near the Golgi at early stages of infection while the L protein was distributed throughout the cytoplasm, further supporting the multifunctional nature of the L protein. These antibodies also allowed us to gain information about the organs and cell types targeted by the virus in vivo. We could detect NSDV in cryosections prepared from various tissues collected post-mortem from experimentally inoculated animals; the virus was found in the mucosal lining of the small and large intestine, in the lungs, and in mesenteric lymph nodes (MLN, where NSDV appeared to target monocytes and/or macrophages.

  16. The C Terminus of the Core β-Ladder Domain in Japanese Encephalitis Virus Nonstructural Protein 1 Is Flexible for Accommodation of Heterologous Epitope Fusion.

    Science.gov (United States)

    Yen, Li-Chen; Liao, Jia-Teh; Lee, Hwei-Jen; Chou, Wei-Yuan; Chen, Chun-Wei; Lin, Yi-Ling; Liao, Ching-Len

    2016-02-01

    NS1 is the only nonstructural protein that enters the lumen of the endoplasmic reticulum (ER), where NS1 is glycosylated, forms a dimer, and is subsequently secreted during flavivirus replication as dimers or hexamers, which appear to be highly immunogenic to the infected host, as protective immunity can be elicited against homologous flavivirus infections. Here, by using a trans-complementation assay, we identified the C-terminal end of NS1 derived from Japanese encephalitis virus (JEV), which was more flexible than other regions in terms of housing foreign epitopes without a significant impact on virus replication. This mapped flexible region is located in the conserved tip of the core β-ladder domain of the multimeric NS1 structure and is also known to contain certain linear epitopes, readily triggering specific antibody responses from the host. Despite becoming attenuated, recombinant JEV with insertion of a neutralizing epitope derived from enterovirus 71 (EV71) into the C-terminal end of NS1 not only could be normally released from infected cells, but also induced dual protective immunity for the host to counteract lethal challenge with either JEV or EV71 in neonatal mice. These results indicated that the secreted multimeric NS1 of flaviviruses may serve as a natural protein carrier to render epitopes of interest more immunogenic in the C terminus of the core β-ladder domain. The positive-sense RNA genomes of mosquito-borne flaviviruses appear to be flexible in terms of accommodating extra insertions of short heterologous antigens into their virus genes. Here, we illustrate that the newly identified C terminus of the core β-ladder domain in NS1 could be readily inserted into entities such as EV71 epitopes, and the resulting NS1-epitope fusion proteins appeared to maintain normal virus replication, secretion ability, and multimeric formation from infected cells. Nonetheless, such an insertion attenuated the recombinant JEV in mice, despite having retained

  17. AJUBA LIM Proteins Limit Hippo Activity in Proliferating Cells by Sequestering the Hippo Core Kinase Complex in the Cytosol.

    Science.gov (United States)

    Jagannathan, Radhika; Schimizzi, Gregory V; Zhang, Kun; Loza, Andrew J; Yabuta, Norikazu; Nojima, Hitoshi; Longmore, Gregory D

    2016-10-15

    The Hippo pathway controls organ growth and is implicated in cancer development. Whether and how Hippo pathway activity is limited to sustain or initiate cell growth when needed is not understood. The members of the AJUBA family of LIM proteins are negative regulators of the Hippo pathway. In mammalian epithelial cells, we found that AJUBA LIM proteins limit Hippo regulation of YAP, in proliferating cells only, by sequestering a cytosolic Hippo kinase complex in which LATS kinase is inhibited. At the plasma membranes of growth-arrested cells, AJUBA LIM proteins do not inhibit or associate with the Hippo kinase complex. The ability of AJUBA LIM proteins to inhibit YAP regulation by Hippo and to associate with the kinase complex directly correlate with their capacity to limit Hippo signaling during Drosophila wing development. AJUBA LIM proteins did not influence YAP activity in response to cell-extrinsic or cell-intrinsic mechanical signals. Thus, AJUBA LIM proteins limit Hippo pathway activity in contexts where cell proliferation is needed. Copyright © 2016 Jagannathan et al.

  18. Rapid reduction of hepatitis C virus-Core protein in the peripheral blood improve the immunological response in chronic hepatitis C patients.

    Science.gov (United States)

    Kondo, Yasuteru; Ueno, Yoshiyuki; Wakui, Yuta; Ninomiya, Masashi; Kakazu, Eiji; Inoue, Jun; Kobayashi, Koju; Obara, Noriyuki; Shimosegawa, Tooru

    2011-12-01

      The extracellular hepatitis C virus (HCV)-antigen, including HCV-Core protein, can suppress immune cells. Recently, the efficacy of double filtration plasmapheresis (DFPP) for chronic hepatitis C (CHC) was reported. However, the mechanism of efficacy of DFPP might not be only the reduction of HCV but also the effect of immune cells via direct and/or indirect mechanisms. The aim of this study is to analyze the virological and immunological parameters of difficult-to-treat HCV patients treated with DFPP combined with Peg-interferon and RBV (DFPP/Peg-IFN/RBV) therapy.   Twelve CHC patients were enrolled and treated with DFPP/Peg-IFN/RBV therapy. The immunological, virological and genetic parameters were studied.   All patients (4/4) treated with the major IL28B allele (T/T) could achieve complete early virological response (EVR). The amounts of HCV-Core antigen in the peripheral blood of EVR patients treated with DFPP/Peg-IFN/RBV rapidly declined in comparison to those of late virological response (LVR) patients treated with DFPP/Peg-IFN/RBV and EVR patients treated with Peg-IFN and RBV (Peg-IFN/RBV). The amount of IFN-γ produced from peripheral blood gradually increased. On the other hand, the amount of IL10 gradually decreased in the EVR patients. The frequencies of HCV-Core binding on CD3+ T cells rapidly declined in EVR patients treated with DFPP/Peg-IFN/RBV therapy. Moreover, the distributions of activated CD4(+) and CD8(+) T cells and CD16-CD56 high natural killer cells were significantly changed between before and after DFPP.   The rapid reduction of HCV-Core antigens and changes in the distribution of lymphoid cells could contribute to the favorable immunological response during DFPP/Peg-IFN/RBV therapy. © 2011 The Japan Society of Hepatology.

  19. Electroacupuncture Suppresses Discrete Cue-Evoked Heroin-Seeking and Fos Protein Expression in the Nucleus Accumbens Core in Rats

    Directory of Open Access Journals (Sweden)

    Sheng Liu

    2012-01-01

    Full Text Available Relapse to drug seeking was studied using a rodent model of reinstatement induced by exposure to drug-related cues. Here, we used intravenous drug self-administration procedures in rats to further investigate the beneficial effects of electroacupuncture (EA on heroin-seeking behavior in a reinstatement model of relapse. We trained Sprague-Dawley rats to nose-poke for i.v. heroin either daily for 4 h or 25 infusions for 14 consecutive days. Then the rats were abstinent from heroin for two weeks. 2 Hz EA stimulation was conducted once daily for 14 days during heroin abstinence. We tested these animals for contextual and discrete cue-induced reinstatement of active responses. We also applied immunohistochemistry to detect Fos-positive nuclei in the nucleus accumbens (NACc core and shell after reinstatement test. We found that active responses elicited by both contextual cues and discrete cues were high in the rats trained with heroin than in saline controls. EA treatment significantly reduced active responses elicited by discrete cues. EA stimulation attenuated Fos expression in the core but not the shell of the NACc. Altogether, these results highlight the therapeutic benefit of EA in preventing relapse to drug addiction.

  20. Food Protein Based Core-Shell Nanocarriers for Oral Drug Delivery: Effect of Shell Composition on in Vitro and in Vivo Functional Performance of Zein Nanocarriers.

    Science.gov (United States)

    Alqahtani, Mohammed S; Islam, M Saiful; Podaralla, Satheesh; Kaushik, Radhey S; Reineke, Joshua; Woyengo, Tofuko; Perumal, Omathanu

    2017-03-06

    The study was aimed at systematically investigating the influence of shell composition on the particle size, stability, release, cell uptake, permeability, and in vivo gastrointestinal distribution of food protein based nanocarriers for oral delivery applications. Three different core-shell nanocarriers were prepared using food-grade biopolymers including zein-casein (ZC) nanoparticles, zein-lactoferrin (ZLF), nanoparticles and zein-PEG (ZPEG) micelles. Nile red was used as a model hydrophobic dye for in vitro studies. The nanocarriers had negative, positive, and neutral charge, respectively. All three nanocarriers had a particle size of less than 200 nm and a low polydispersity index. The nanoparticles were stable at gastrointestinal pH (2-9) and ionic strength (10-200 mM). The nanocarriers sustained the release of Nile red in simulated gastric and intestinal fluids. ZC nanoparticles showed the slowest release followed by ZLF nanoparticles and ZPEG micelles. The nanocarriers were taken up by endocytosis in Caco-2 cells. ZPEG micelles showed the highest cell uptake and transepithelial permeability followed by ZLF and ZC nanoparticles. ZPEG micelles also showed P-gp inhibitory activity. All three nanocarriers showed bioadhesive properties. Cy 5.5, a near IR dye, was used to study the in vivo biodistribution of the nanocarriers. The nanocarriers showed longer retention in the rat gastrointestinal tract compared to the free dye. Among the three formulations, ZC nanoparticles was retained the longest in the rat gastrointestinal tract (≥24 h). Overall, the outcomes from this study demonstrate the structure-function relationship of core-shell protein nanocarriers. The findings from this study can be used to develop food protein based oral drug delivery systems with specific functional attributes.

  1. In the yeast Hansenula polymorpha, peroxisome formation from the ER is independent of Pex19p, but involves the function of p24 proteins

    NARCIS (Netherlands)

    Otzen, Marleen; Krikken, Arjen M; Ozimek, Paulina Z; Kurbatova, Elena; Nagotu, Shirisha; Veenhuis, Marten; van der Klei, Ida J

    2006-01-01

    The peroxin Pex19p is important for the formation of functional peroxisomal membranes. Here we show that Hansenula polymorpha Pex19p is also required for peroxisome inheritance. Peroxisome inheritance is partly defective when Pex19p farnesylation is blocked, whereas deletion of PEX19 resulted in a

  2. Proteomics Core

    Data.gov (United States)

    Federal Laboratory Consortium — Proteomics Core is the central resource for mass spectrometry based proteomics within the NHLBI. The Core staff help collaborators design proteomics experiments in a...

  3. A DNA Structural Alphabet Distinguishes Structural Features of DNA Bound to Regulatory Proteins and in the Nucleosome Core Particle

    Czech Academy of Sciences Publication Activity Database

    Schneider, Bohdan; Bozikova, Paulina; Čech, P.; Svozil, D.; Černý, Jiří

    2017-01-01

    Roč. 8, č. 10 (2017), č. článku 278. ISSN 2073-4425 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0109 Grant - others:GA MŠk(CZ) EF16_013/0001777 Institutional support: RVO:86652036 Keywords : DNA * DNA-protein recognition * transcription factors Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Computer sciences, information science, bioinformathics (hardware development to be 2.2, social aspect to be 5.8) Impact factor: 3.600, year: 2016

  4. Variability within a pea core collection of LEAM and HSP22, two mitochondrial seed proteins involved in stress tolerance.

    Science.gov (United States)

    Avelange-Macherel, Marie-Hélène; Payet, Nicole; Lalanne, David; Neveu, Martine; Tolleter, Dimitri; Burstin, Judith; Macherel, David

    2015-07-01

    LEAM, a late embryogenesis abundant protein, and HSP22, a small heat shock protein, were shown to accumulate in the mitochondria during pea (Pisum sativum L.) seed development, where they are expected to contribute to desiccation tolerance. Here, their expression was examined in seeds of 89 pea genotypes by Western blot analysis. All genotypes expressed LEAM and HSP22 in similar amounts. In contrast with HSP22, LEAM displayed different isoforms according to apparent molecular mass. Each of the 89 genotypes harboured a single LEAM isoform. Genomic and RT-PCR analysis revealed four LEAM genes differing by a small variable indel in the coding region. These variations were consistent with the apparent molecular mass of each isoform. Indels, which occurred in repeated domains, did not alter the main properties of LEAM. Structural modelling indicated that the class A α-helix structure, which allows interactions with the mitochondrial inner membrane in the dry state, was preserved in all isoforms, suggesting functionality is maintained. The overall results point out the essential character of LEAM and HSP22 in pea seeds. LEAM variability is discussed in terms of pea breeding history as well as LEA gene evolution mechanisms. © 2014 John Wiley & Sons Ltd.

  5. Mapping the signal peptide binding and oligomer contact sites of the core subunit of the pea twin arginine protein translocase.

    Science.gov (United States)

    Ma, Xianyue; Cline, Kenneth

    2013-03-01

    Twin arginine translocation (Tat) systems of thylakoid and bacterial membranes transport folded proteins using the proton gradient as the sole energy source. Tat substrates have hydrophobic signal peptides with an essential twin arginine (RR) recognition motif. The multispanning cpTatC plays a central role in Tat operation: It binds the signal peptide, directs translocase assembly, and may facilitate translocation. An in vitro assay with pea (Pisum sativum) chloroplasts was developed to conduct mutagenesis and analysis of cpTatC functions. Ala scanning mutagenesis identified mutants defective in substrate binding and receptor complex assembly. Mutations in the N terminus (S1) and first stromal loop (S2) caused specific defects in signal peptide recognition. Cys matching between substrate and imported cpTatC confirmed that S1 and S2 directly and specifically bind the RR proximal region of the signal peptide. Mutations in four lumen-proximal regions of cpTatC were defective in receptor complex assembly. Copurification and Cys matching analyses suggest that several of the lumen proximal regions may be important for cpTatC-cpTatC interactions. Surprisingly, RR binding domains of adjacent cpTatCs directed strong cpTatC-cpTatC cross-linking. This suggests clustering of binding sites on the multivalent receptor complex and explains the ability of Tat to transport cross-linked multimers. Transport of substrate proteins cross-linked to the signal peptide binding site tentatively identified mutants impaired in the translocation step.

  6. An Ultrasensitive Electrochemical Immunosensor for HIV p24 Based on Fe3O4@SiO2 Nanomagnetic Probes and Nanogold Colloid-Labeled Enzyme–Antibody Copolymer as Signal Tag

    Directory of Open Access Journals (Sweden)

    Tianhua Li

    2013-03-01

    Full Text Available An ultrasensitive portable electrochemical immunosensor for human immunodeficiency virus p24 (HIV p24 antigen detection has been developed, whereby the detection sensitivity was 1000 times higher than that of the ELISA method. Firstly, a novel HRP enzyme–antibody copolymer (EV-p24 Ab2 was synthesized through an EnVision regent (EV, a dextrin amine skeleton anchoring more than 100 molecules of HRP and 15 molecules of anti IgG, then incubated in the secondary antibody of p24. Secondly, the copolymer was immobilized on the gold nanocolloids (AuNPs to fabricate a novel signal tag (AuNPs/EV-p24 Ab2. Subsequently, a sandwich-type immunoreaction would take place between the capture probe (silicon dioxide-coated magnetic Fe3O4 nanoparticles (MNPs labeled with the primary p24 antibody (MNPs-p24 Ab1, p24 (different concentrations and the signal tag [AuNPs/EV-p24 Ab2] to form the immunocomplex. Finally, the immunocomplex was absorbed on the surface of screen printed carbon electrode (SPCE by a magnet and immersed in the o-hydroxyl phenol (HQ and H2O2. The large amounts of HRP on the signal tag can catalyze the oxidation of HQ by H2O2, which can induce an amplified reductive current. Moreover, the capture probe could improve the accumulation ability of p24 and facilitate its separation from the substrate through the magnet. Under optimal conditions, the proposed immunoassay exhibited good sensitivity to p24 within a certain concentration range from 0.001 to 10.00 ng/mL, with a detection limit of 0.5 pg/mL (S/N = 3. The proposed method can be used for real-time and early detection of HIV-infected people.

  7. MacA, a periplasmic membrane fusion protein of the macrolide transporter MacAB-TolC, binds lipopolysaccharide core specifically and with high affinity.

    Science.gov (United States)

    Lu, Shuo; Zgurskaya, Helen I

    2013-11-01

    The Escherichia coli MacAB-TolC transporter has been implicated in efflux of macrolide antibiotics and secretion of enterotoxin STII. In this study, we found that purified MacA, a periplasmic membrane fusion protein, contains one tightly bound rough core lipopolysaccharide (R-LPS) molecule per MacA molecule. R-LPS was bound specifically to MacA protein with affinity exceeding that of polymyxin B. Sequence analyses showed that MacA contains two high-density clusters of positively charged amino acid residues located in the cytoplasmic N-terminal domain and the periplasmic C-terminal domain. Substitutions in the C-terminal cluster reducing the positive-charge density completely abolished binding of R-LPS. At the same time, these substitutions significantly reduced the functionality of MacA in the protection of E. coli against macrolides in vivo and in the in vitro MacB ATPase stimulation assays. Taken together, our results suggest that R-LPS or a similar glycolipid is a physiological substrate of MacAB-TolC.

  8. Key Feature of the Catalytic Cycle of TNF-α Converting Enzyme Involves Communication Between Distal Protein Sites and the Enzyme Catalytic Core

    International Nuclear Information System (INIS)

    Solomon, A.; Akabayov, B.; Frenkel, A.; Millas, M.; Sagi, I.

    2007-01-01

    Despite their key roles in many normal and pathological processes, the molecular details by which zinc-dependent proteases hydrolyze their physiological substrates remain elusive. Advanced theoretical analyses have suggested reaction models for which there is limited and controversial experimental evidence. Here we report the structure, chemistry and lifetime of transient metal-protein reaction intermediates evolving during the substrate turnover reaction of a metalloproteinase, the tumor necrosis factor-α converting enzyme (TACE). TACE controls multiple signal transduction pathways through the proteolytic release of the extracellular domain of a host of membrane-bound factors and receptors. Using stopped-flow x-ray spectroscopy methods together with transient kinetic analyses, we demonstrate that TACE's catalytic zinc ion undergoes dynamic charge transitions before substrate binding to the metal ion. This indicates previously undescribed communication pathways taking place between distal protein sites and the enzyme catalytic core. The observed charge transitions are synchronized with distinct phases in the reaction kinetics and changes in metal coordination chemistry mediated by the binding of the peptide substrate to the catalytic metal ion and product release. Here we report key local charge transitions critical for proteolysis as well as long sought evidence for the proposed reaction model of peptide hydrolysis. This study provides a general approach for gaining critical insights into the molecular basis of substrate recognition and turnover by zinc metalloproteinases that may be used for drug design

  9. Identification of a human protein-derived HIV-1 fusion inhibitor targeting the gp41 fusion core structure.

    Directory of Open Access Journals (Sweden)

    Lijun Chao

    Full Text Available The HIV-1 envelope glycoprotein (Env gp41 plays a crucial role in the viral fusion process. The peptides derived from the C-terminal heptad repeat (CHR of gp41 are potent HIV fusion inhibitors. However, the activity of these anti-HIV-1 peptides in vivo may be attenuated by their induction of anti-gp41 antibodies. Thus, it is essential to identify antiviral peptides or proteins with low, or no, immunogenicity to humans. Here, we found that the C-terminal fragment (aa 462-521 of the human POB1 (the partner of RalBP1, designated C60, is an HIV-1 fusion inhibitor. It bound to N36, the peptide derived from the N-terminal heptad repeat (NHR of gp41, and to the six-helix bundle (6-HB formed by N36 and C34, a CHR-peptide, but it did not bind to C34. Unlike the CHR-peptides, C60 did not block gp41 6-HB formation. Rather, results suggest that C60 inhibits HIV-1 fusion by binding to the 6-HB, in particular, the residues in the gp41 NHR domain that are exposed on the surface of 6-HB. Since 6-HB plays a crucial role in the late stage of fusion between the viral envelope and endosomal membrane during the endocytic process of HIV-1, C60 may serve as a host restriction factor to suppress HIV-1 entry into CD4+ T lymphocytes. Taken together, it can be concluded from these results that C60 can be used as a lead for the development of anti-HIV-1 therapeutics or microbicides for the treatment and prevention of HIV-1 infection, as well as a molecular probe to study the fusogenic mechanism of HIV-1.

  10. Nuclear export of human hepatitis B virus core protein and pregenomic RNA depends on the cellular NXF1-p15 machinery.

    Science.gov (United States)

    Yang, Ching-Chun; Huang, Er-Yi; Li, Hung-Cheng; Su, Pei-Yi; Shih, Chiaho

    2014-01-01

    Hepatitis B virus (HBV) core protein (HBc) can shuttle between nucleus and cytoplasm. Cytoplasm-predominant HBc is clinically associated with severe liver inflammation. Previously, we found that HBc arginine-rich domain (ARD) can associate with a host factor NXF1 (TAP) by coimmunoprecipitation. It is well known that NXF1-p15 heterodimer can serve as a major export receptor of nuclear mRNA as a ribonucleoprotein complex (RNP). In the NXF1-p15 pathway, TREX (transcription/export) complex plays an important role in coupling nuclear pre-mRNA processing with mRNA export in mammalian cells. Here, we tested the hypothesis whether HBc and HBV specific RNA can be exported via the TREX and NXF1-p15 mediated pathway. We demonstrated here that HBc can physically and specifically associate with TREX components, and the NXF1-p15 export receptor by coimmunoprecipitation. Accumulation of HBc protein in the nucleus can be induced by the interference with TREX and NXF1-p15 mediated RNA export machinery. HBV transcripts encodes a non-spliced 3.5 kb pregenomic RNA (pgRNA) which can serve as a template for reverse transcription. Cytoplasmic HBV pgRNA appeared to be reduced by siRNA treatment specific for the NXF1-p15 complex by quantitative RT-qPCR and Northern blot analyses. This result suggests that the pgRNA was also exported via the NXF1-p15 machinery. We entertain the hypothesis that HBc protein can be exported as an RNP cargo via the mRNA export pathway by hijacking the TREX and NXF1-p15 complex. In our current and previous studies, HBc is not required for pgRNA accumulation in the cytoplasm. Furthermore, HBc ARD can mediate nuclear export of a chimeric protein containing HBc ARD in a pgRNA-independent manner. Taken together, it suggests that while both pgRNA and HBc protein exports are dependent on NXF1-p15, they are using the same export machinery in a manner independent of each other.

  11. Development and application of hepatitis C reporter viruses with genotype 1 to 7 core-nonstructural protein 2 (NS2) expressing fluorescent proteins or luciferase in modified JFH1 NS5A

    DEFF Research Database (Denmark)

    Gottwein, Judith M; Jensen, Tanja B; Mathiesen, Christian K

    2011-01-01

    to 2a(J6) tagged with EGFP, DsRed-Express2, mCherry, or Renilla luciferase (RLuc), yielding peak supernatant infectivity titers of 4 to 5 log(10) focus-forming units (FFU)/ml. 2a(J6) with ¿40 or ¿25 was fully viable in Huh7.5 cells. In human liver chimeric mice, 2a(J6)-EGFP¿40 acquired various...... deletions in EGFP, while 2a(J6)¿40 did not show an impaired viability. We further developed panels of JFH1-based genotype 1 to 7 core-NS2 recombinants expressing EGFP- or RLuc-NS5A¿40 fusion proteins. In cell culture, the different EGFP recombinants showed growth characteristics comparable to those...

  12. Expression and partial characterization of an ice binding protein from a bacterium isolated at a depth of 3,519 meters in the Vostok ice core, Antarctica

    Directory of Open Access Journals (Sweden)

    Amanda Marie Achberger

    2011-12-01

    Full Text Available Cryopreservation of microorganisms in ancient glacial ice is possible if lethal levels of macromolecular damage are not incurred and cellular integrity is not compromised via intracellular ice formation or recrystallization. Previously, a bacterium (isolate 3519-10 recovered from a depth of 3,519 meters below the surface in the Vostok ice core was shown to secrete an IBP that inhibits the recrystallization of ice. To explore the advantage that IBPs confer to ice-entrapped cells, experiments were designed to examine the expression of 3519-10’s IBP gene and protein at different temperatures, assess the effect of the IBP on bacterial viability in ice, and determine how the IBP influences the physical structure of the ice. Total RNA isolated from cultures grown between 4 to 25⁰C and analyzed by reverse transcription-PCR indicated constitutive expression of the IBP gene. SDS-PAGE analysis of 3519-10’s extracellular proteins also revealed a polypeptide of the predicted size of the 54 kDa IBP at all temperatures tested. In the presence of 100 µg mL-1 of extracellular protein from 3519-10, the survival of Escherichia coli was increased by greater than 34-fold after freeze-thaw cycling. Microscopic analysis of ice formed in the presence of the IBP indicated that per mm2 field of view, there were ~5 times as many crystals as in ice formed in the presence of washed 3519-10 cells and non-IBP producing bacteria, and ~10 times as many crystals as in filtered deionized water. Presumably, the effect that the IBP has on bacterial viability and ice crystal structure is due to its activity as an inhibitor of ice recrystallization. A myriad of molecular adaptations are likely to play a role in bacterial persistence under frozen conditions, but the ability of 3519-10’s IBP to control ice crystal structure, and thus the liquid vein network within the ice, may provide one explanation for its successful survival deep within the Antarctic ice sheet for

  13. DNA immunization with fusion of CTLA-4 to hepatitis B virus (HBV core protein enhanced Th2 type responses and cleared HBV with an accelerated kinetic.

    Directory of Open Access Journals (Sweden)

    Ying Yin

    Full Text Available BACKGROUND: Typically, DNA immunization via the intramuscular route induces specific, Th1-dominant immune responses. However, plasmids expressing viral proteins fused to cytotoxic T lymphocyte antigen 4 (CTLA-4 primed Th2-biased responses and were able to induced effective protection against viral challenge in the woodchuck model. Thus, we addressed the question in the mouse model how the Th1/Th2 bias of primed immune responses by a DNA vaccine influences hepatitis B virus (HBV clearance. PRINCIPAL FINDINGS: Plasmids expressing HBV core protein (HBcAg or HBV e antigen and HBcAg fused to the extracellular domain of CTLA-4 (pCTLA-4-HBc, CD27, and full length CD40L were constructed. Immunizations of these DNA plasmids induced HBcAg-specific antibody and cytotoxic T-cell responses in mice, but with different characteristics regarding the titers and subtypes of specific antibodies and intensity of T-cell responses. The plasmid pHBc expressing HBcAg induced an IgG2a-dominant response while immunizations of pCTLA-4-HBc induced a balanced IgG1/IgG2a response. To assess the protective values of the immune responses of different characteristics, mice were pre-immunized with pCTLA-4-HBc and pHBc, and challenged by hydrodynamic injection (HI of pAAV/HBV1.2. HBV surface antigen (HBsAg and DNA in peripheral blood and HBcAg in liver tissue were cleared with significantly accelerated kinetics in both groups. The clearance of HBsAg was completed within 16 days in immunized mice while more than 50% of the control mice are still positive for HBsAg on day 22. Stronger HBcAg-specific T-cell responses were primed by pHBc correlating with a more rapid decline of HBcAg expression in liver tissue, while anti-HBs antibody response developed rapidly in the mice immunized with pCTLA-4-HBc, indicating that the Th1/Th2 bias of vaccine-primed immune responses influences the mode of viral clearance. CONCLUSION: Viral clearance could be efficiently achieved by Th1/Th2-balanced

  14. Human recombinant Fab fragment from combinatorial libraries of a B-cell lymphoma patient recognizes core protein of chondroitin sulphate proteoglycan 4.

    Science.gov (United States)

    Egami, Yoko; Narushima, Yuta; Ohshima, Motohiro; Yoshida, Akira; Yoneta, Naruki; Masaki, Yasufumi; Itoh, Kunihiko

    2018-01-01

    CD antigens are well known as therapeutic targets of B-cell lymphoma. To isolate therapeutic antibodies that recognize novel targets other than CD antigens, we constructed a phage display combinatorial antibody Fab library from bone marrow lymphocytes of B-cell lymphoma patient. To eliminate antibodies reactive with known B-cell lymphoma antigen, non-hematopoietic and patient's sera reactive HeLaS3 cells was selected as a target of whole cell panning. Five rounds of panning against live HeLaS3 cells retrieved single Fab clone, termed AHSA (Antibody to HeLa Surface Antigen). Using phage display random peptide library, LSYLEP was identified as an epitope sequence of AHSA. LC-MS/MS analysis of AHSA-precipitated HeLaS3 cell lysates detected several fragments corresponding to the sequence of chondroitin sulphate proteoglycan 4 (CSPG4) core protein. Since LSYLEP sequence was at the position of 313-318 of CSPG4, we considered that CSPG4 was AHSA-associated antigen. Double staining of CSPG4-postive MDA-MB-435S cells with AHSA and anti-CSPG4 rabbit antibody showed identical staining position, and reduced AHSA reactivity was observed in CSPG4-siRNA treated MDA-MB-435S cells. In conclusion, we retrieved a human Fab from antibody library of B-cell lymphoma patient, and identified CSPG4 as a recognizing antigen. AHSA may have potential benefits for development of CSPG4-targeting theranostics for B-cell lymphoma. © The Authors 2017. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

  15. Transformer core

    NARCIS (Netherlands)

    Mehendale, A.; Hagedoorn, Wouter; Lötters, Joost Conrad

    2008-01-01

    A transformer core includes a stack of a plurality of planar core plates of a magnetically permeable material, which plates each consist of a first and a second sub-part that together enclose at least one opening. The sub-parts can be fitted together via contact faces that are located on either side

  16. Transformer core

    NARCIS (Netherlands)

    Mehendale, A.; Hagedoorn, Wouter; Lötters, Joost Conrad

    2010-01-01

    A transformer core includes a stack of a plurality of planar core plates of a magnetically permeable material, which plates each consist of a first and a second sub-part that together enclose at least one opening. The sub-parts can be fitted together via contact faces that are located on either side

  17. Intellectual disability, muscle weakness and characteristic face in three siblings: A newly described recessive syndrome mapping to 3p24.3-p25.3.

    Science.gov (United States)

    Kariminejad, Ariana; Nafissi, Shahriar; Nilipoor, Yalda; Tavasoli, Alireza; Van Veldhoven, Paul P; Bonnard, Carine; Ng, Yeng Ting; Majoie, Charles B; Reversade, Bruno; Hennekam, Raoul C

    2015-11-01

    We report on a sister and two brothers born to healthy Iranian parents with mild intellectual disability, progressive muscle weakness, and characteristic facies. including highly arched eyebrows, down-slanting palpebral fissures, prominent nasal bridge, prominent nose, columella extending below alae nasi, narrow mouth, narrow palate, and dental caries, and in one of them an inability to abduct the left eye. Electrophysiological studies showed signs of myopathy, and muscle biopsies demonstrated only nonspecific signs. Brain MRIs in two of the sibs showed leukencephalopathy with delayed myelination, frontal and parietal hyperintensities, and hippocampal atrophy in one. We have been unable to find a description of this association of features in literature. Based on the occurrence in siblings, no significant difference in phenotype between the brothers and sister, absence of manifestations in parents, and a likely consanguinity between parents we performed a homozygosity mapping. A single identical-by-descent bloc encompassing 57 genes located at 3p24.3-p25.3 was found to segregate within the family with this phenotype. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  18. Core lifter

    Energy Technology Data Exchange (ETDEWEB)

    Pavlov, N G; Edel' man, Ya A

    1981-02-15

    A core lifter is suggested which contains a housing, core-clamping elements installed in the housing depressions in the form of semirings with projections on the outer surface restricting the rotation of the semirings in the housing depressions. In order to improve the strength and reliability of the core lifter, the semirings have a variable transverse section formed from the outside by the surface of the rotation body of the inner arc of the semiring aroung the rotation axis and from the inner a cylindrical surface which is concentric to the outer arc of the semiring. The core-clamping elements made in this manner have the possibility of freely rotating in the housing depressions under their own weight and from contact with the core sample. These semirings do not have weakened sections, have sufficient strength, are inserted into the limited ring section of the housing of the core lifter without reduction in its through opening and this improve the reliability of the core lifter in operation.

  19. Autosomal dominant hereditary sensory neuropathy with chronic cough and gastro-oesophageal reflux: clinical features in two families linked to chromosome 3p22-p24.

    Science.gov (United States)

    Spring, Penelope J; Kok, Cindy; Nicholson, Garth A; Ing, Alvin J; Spies, Judith M; Bassett, Mark L; Cameron, John; Kerlin, Paul; Bowler, Simon; Tuck, Roger; Pollard, John D

    2005-12-01

    Autosomal dominant hereditary sensory neuropathy (HSN I) is a clinically and genetically heterogeneous group of disorders, and in some families it is due to mutations in the serine palmitoyltransferase (SPTLC1) gene. We have characterized two families with HSN I associated with cough and gastro-oesophageal reflux (GOR). From a large Australian family, 27 individuals and from a smaller family, 11 individuals provided clinical information and blood for genetic analysis. Affected individuals had an adult onset of paroxysmal cough, GOR and distal sensory loss. Cough could be triggered by noxious odours or by pressure in the external auditory canal (Arnold's ear-cough reflex). Other features included throat clearing, hoarse voice, cough syncope and sensorineural hearing loss. Neurophysiological and pathological studies demonstrated a sensory axonal neuropathy. Gastric emptying studies were normal, and autonomic function and sweat tests were either normal or showed distal hypohidrosis. Cough was likely to be due to a combination of denervation hypersensitivity of the upper airways and oesophagus, and prominent GOR. Most affected individuals were shown on 24 h ambulatory oesophageal pH monitoring to have multiple episodes of GOR, closely temporally associated with coughing. Hoarse voice was probably attributable to acid-induced laryngeal damage, and there was no evidence of vocal cord palsy. No other cause for cough was found on most respiratory or otorhinological studies. Linkage to chromosome 3p22-p24 has been found in both families, with no evidence of linkage to loci for known HSN I, autosomal dominant hereditary motor and sensory neuropathy, hereditary GOR or triple A syndrome. These families represent a genetically novel variant of HSN I, with a distinctive cough owing to involvement of the upper aerodigestive tract.

  20. Creep performance of welded pipe material made of 7CrMoVTiB10-10 (T/P24) steel

    Energy Technology Data Exchange (ETDEWEB)

    Rantala, Juhani; Auerkari, Pertti; Salonen, Jorma; Holmstroem, Stefan; Nevasmaa, Pekka [VTT Technical Research Centre of Finland, Espoo (Finland); Haekkilae, Juha [Foster Wheeler Energia, Varkaus (Finland)

    2010-07-01

    The creep strength of welded low-alloy ferritic steels is typically somewhat lower than that for parent metal, but this is generally due to an inherent weakness of the heat affected zone and accounted for in the common design codes. However, the parent material strength is much higher in certain modern low alloy steels such as 7CrMoVTiB10-10 (P24), and then it can be a significant challenge to develop weld metals (welding consumables) to match this strength. Acceptable weld performance has been previously demonstrated for thin-wall tubes where sufficient mixing with the base material can occur. The objective of this work was to achieve satisfactory properties for a thick-wall welded pipe by using an Nb-modified consumable to avoid weld metal weakening due to arc losses of Ti of a consumable composition approximately matching the base material. A considerable improvement was indeed noted in comparison with earlier experience using matching electrode composition. All short term test results for weld qualification showed acceptable properties, the cross-weld creep strength remain very close to the -20% band from the parent metal creep strength. However, creep testing at lowest stress levels approaching those expected in service resulted in weld metal failure. Although a clear improvement is evident from the previous generation of weld metals, there appears to be some further scope of development of the welding consumables, to improve the long term creep ductility of the welded joints particularly when applying production-like welding parameters. (orig.)

  1. Reactor core

    International Nuclear Information System (INIS)

    Azekura, Kazuo; Kurihara, Kunitoshi.

    1992-01-01

    In a BWR type reactor, a great number of pipes (spectral shift pipes) are disposed in the reactor core. Moderators having a small moderating cross section (heavy water) are circulated in the spectral shift pipes to suppress the excess reactivity while increasing the conversion ratio at an initial stage of the operation cycle. After the intermediate stage of the operation cycle in which the reactor core reactivity is lowered, reactivity is increased by circulating moderators having a great moderating cross section (light water) to extend the taken up burnup degree. Further, neutron absorbers such as boron are mixed to the moderator in the spectral shift pipe to control the concentration thereof. With such a constitution, control rods and driving mechanisms are no more necessary, to simplify the structure of the reactor core. This can increase the fuel conversion ratio and control great excess reactivity. Accordingly, a nuclear reactor core of high conversion and high burnup degree can be attained. (I.N.)

  2. Ice Cores

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Records of past temperature, precipitation, atmospheric trace gases, and other aspects of climate and environment derived from ice cores drilled on glaciers and ice...

  3. Prevalence of human immunodeficiency virus type 1 p24 antigen in U.S. blood donors--an assessment of the efficacy of testing in donor screening. The HIV-Antigen Study Group.

    Science.gov (United States)

    Alter, H J; Epstein, J S; Swenson, S G; VanRaden, M J; Ward, J W; Kaslow, R A; Menitove, J E; Klein, H G; Sandler, S G; Sayers, M H

    1990-11-08

    We performed a multicenter study in 1989 to determine whether screening whole-blood donors for human immunodeficiency virus type 1 (HIV-1) p24 antigen would improve transfusion safety by identifying carriers of the virus who are seronegative for HIV-1 antibody. More than 500,000 donations were tested at 13 U.S. blood centers with test kits from two manufacturers. Units found repeatedly reactive were retested in a central laboratory; if the results were positive, they were confirmed by a neutralization assay. A subgroup of units was also tested for HIV-1 by the polymerase chain reaction. Selected donors confirmed or not confirmed as having p24 antigen were contacted for follow-up interviews to identify risk factors and undergo retesting for HIV-1 markers. Positive tests for p24 antigen were confirmed by neutralization in five donors (0.001 percent of all donations tested), all of whom were also positive for HIV-1 antibody and HIV-1 by polymerase chain reaction. Three of the antigen-positive donors had other markers of infectious disease that would have resulted in the exclusion of their blood; two had risk factors for HIV-1 that should have led to self-exclusion. Of 220 blood units with repeatedly reactive p24 antigen whose presence could not be confirmed by neutralization (0.04 percent of the donations studied), none were positive for HIV-1 antibody, HIV-1 by polymerase chain reaction (120 units tested), or virus culture (76 units tested)--attesting to the specificity of confirmatory neutralization. The finding that no donation studied was positive for p24 antigen and negative for HIV-1 antibody suggests that screening donors for p24 antigen with tests of the current level of sensitivity would not add substantially to the safety of the U.S. blood supply.

  4. Serum Level of Antibodies Against Hepatitis B Core Protein Is Associated With Clinical Relapse After Discontinuation of Nucleos(t)ide Analogue Therapy.

    Science.gov (United States)

    Chi, Heng; Li, Zhandong; Hansen, Bettina E; Yu, Tao; Zhang, Xiaoyong; Sun, Jian; Hou, Jinlin; Janssen, Harry L A; Peng, Jie

    2018-06-11

    Levels of antibodies against the hepatitis B virus (HBV) core protein (anti-HBc) have been associated with response to nucleos(t)ide analogue and (peg)interferon therapy in patients with chronic HBV infection. We performed a prospective study to determine whether the total serum level of anti-HBc level (immunoglobulins M and G) is associated with clinical relapse after discontinuation of nucleos(t)ide analogue-based therapy. We collected data from patients with chronic HBV infection who discontinued nucleos(t)ide analogue therapy according to pre-specified stopping criteria, recruited from November 2012 through July 2016 at an academic hospital in Guangzhou, China. Patients were followed through February 2017. We performed comprehensive biochemical and virologic tests at every visit, and anti-HBc was quantified for 2 years after treatment cessation (at baseline and weeks 4, 8, 12, 24, 48, and 96). The primary endpoint was clinical relapse, defined as level of HBV DNA >2000 IU/mL and level of alanine aminotransferase more than 2-fold the upper limit of normal-these were also the criteria for retreatment. We followed 100 patients (71% positive for HB e antigen [HBeAg] at the start of nucleos(t)ide analogue therapy, 43% treated with entecavir or tenofovir) for a median of 2.5 years after stopping therapy. Clinical relapse occurred in 39 patients (in 46% of patients at year 4 after discontinuation). High level of anti-HBc at the end of treatment (hazard ratio [HR], 0.31 per log IU/mL; P=.002) and low level of HB surface antigen (HBsAg) at the end of treatment (HR, 1.71 per log IU/mL; P=.032) were associated with a reduced risk of clinical relapse after adjusting for age, start of nucleos(t)ide analogue therapy HBeAg-status, and consolidation therapy duration. At year 4, 21% of patients with anti-HBc levels at the end of treatment ≥1000 IU/mL developed a clinical relapse compared to 85% of patients with levels level at the end of treatment ≤100 IU/mL was associated

  5. Reactor core

    International Nuclear Information System (INIS)

    Matsuura, Tetsuaki; Nomura, Teiji; Tokunaga, Kensuke; Okuda, Shin-ichi

    1990-01-01

    Fuel assemblies in the portions where the gradient of fast neutron fluxes between two opposing faces of a channel box is great are kept loaded at the outermost peripheral position of the reactor core also in the second operation cycle in the order to prevent interference between a control rod and the channel box due to bending deformation of the channel box. Further, the fuel assemblies in the second row from the outer most periphery in the first operation cycle are also kept loaded at the second row in the second operation cycle. Since the gradient of the fast neutrons in the reactor core is especially great at the outer circumference of the reactor core, the channel box at the outer circumference is bent such that the surface facing to the center of the reactor core is convexed and the channel box in the second row is also bent to the identical direction, the insertion of the control rod is not interfered. Further, if the positions for the fuels at the outermost periphery and the fuels in the second row are not altered in the second operation cycle, the gaps are not reduced to prevent the interference between the control rod and the channel box. (N.H.)

  6. Reduction of protein adsorption to a solid surface by a coating composed of polymeric micelles with a glass-like core

    NARCIS (Netherlands)

    Hofs, P.S.; Brzozowska, A.M.; Keizer, de A.; Norde, W.; Cohen Stuart, M.A.

    2008-01-01

    Adsorption studies by optical reflectometry show that complex coacervate core micelles (C3Ms) composed of poly([4-(2-amino-ethylthio)-butylene] hydrochloride)49-block-poly(ethylene oxide)212 and poly([4-(2-carboxy-ethylthio)-butylene] sodium salt)47-block-poly(ethylene oxide)212 adsorb in equal

  7. Reduction of protein adsorption to a solid surface by a coating composed of polymeric micelles with a glass-like core

    NARCIS (Netherlands)

    Hofs, B.; Brzozowska, A.; de Keizer, A.; Norde, W.; Stuart, Martien A. Cohen

    2008-01-01

    Adsorption studies by optical reflectometry show that complex coacervate core micelles (C3Ms) composed of poly([4-(2-amino-ethylthio)-butylene]hydrochloride)(49)-block-poly(ethylene oxide)(212) and poly([4-(2carboxy-ethylthio)-butylene] sodium salt)(47)-block-poly(ethylene oxide)(212) adsorb in

  8. Hepatitis B virus (HBV)-specific T-cell responses to recombinant HBV core protein in patients with normal liver function and co-infected with chronic HBV and human immunodeficiency virus 1 (HIV-1)

    Science.gov (United States)

    2013-01-01

    Background Little is known about HBV-specific T-cell responses in chronic Hepatitis B patients (HBV) that are co-infected with Human immunodeficiency virus type 1 (HIV-1), especially those with normal alanine aminotransferase (ALT) levels. Methods Twenty-five patients with chronic HBV (11 hepatitis B e antigen [HBeAg]-positive, 14 HBeAg-negative) were enrolled in a cross-sectional study. A longitudinal study as also conducted in which follow-up was done at 3, 12, and 24 months, after acute HIV-1 infection, in 11 individuals who also had chronic HBV. Peripheral blood mononuclear cells were stimulated with recombinant HBV surface protein (S protein), core protein (C protein) or gag peptide. IFN-γ-secreting T cells were identified by ELISPOT assay. Results In the cross-sectional study, co-infected chronic HBV patients had lower C protein-specific T-cell responses compared with mono-infected individuals, though the difference was not significant. In co-infected, chronic HBV patients, the magnitude of C protein-specific T-cell responses was significantly greater in HBeAg-positive subjects compared to HBeAg-negative subjects (p = 0.011). C protein-specific T-cell responses were positively correlated with HBV viral load (rs = 0.40, p = 0.046). However, gag-specific T-cell responses were negatively correlated with HIV viral load (rs = −0.44, p = 0.026) and positively correlated with CD4+ count (rs = 0.46, p = 0.021). The results were different in mono-infected individuals. PBMCs from co-infected HBeAg-positive patients secreted more specific-IFN-γ in cultured supernatants compared with PBMCs from co-infected HBeAg-negative patients (p = 0.019). In the longitudinal study, S protein- and C protein-specific T-cell responses were decreased as the length of follow-up increased (p = 0.034, for S protein; p = 0.105, for C protein). Additionally, the S protein- and C protein-specific T-cell responses were significantly higher in HBe

  9. Comparing side chain packing in soluble proteins, protein-protein interfaces, and transmembrane proteins.

    Science.gov (United States)

    Gaines, J C; Acebes, S; Virrueta, A; Butler, M; Regan, L; O'Hern, C S

    2018-05-01

    We compare side chain prediction and packing of core and non-core regions of soluble proteins, protein-protein interfaces, and transmembrane proteins. We first identified or created comparable databases of high-resolution crystal structures of these 3 protein classes. We show that the solvent-inaccessible cores of the 3 classes of proteins are equally densely packed. As a result, the side chains of core residues at protein-protein interfaces and in the membrane-exposed regions of transmembrane proteins can be predicted by the hard-sphere plus stereochemical constraint model with the same high prediction accuracies (>90%) as core residues in soluble proteins. We also find that for all 3 classes of proteins, as one moves away from the solvent-inaccessible core, the packing fraction decreases as the solvent accessibility increases. However, the side chain predictability remains high (80% within 30°) up to a relative solvent accessibility, rSASA≲0.3, for all 3 protein classes. Our results show that ≈40% of the interface regions in protein complexes are "core", that is, densely packed with side chain conformations that can be accurately predicted using the hard-sphere model. We propose packing fraction as a metric that can be used to distinguish real protein-protein interactions from designed, non-binding, decoys. Our results also show that cores of membrane proteins are the same as cores of soluble proteins. Thus, the computational methods we are developing for the analysis of the effect of hydrophobic core mutations in soluble proteins will be equally applicable to analyses of mutations in membrane proteins. © 2018 Wiley Periodicals, Inc.

  10. Core BPEL

    DEFF Research Database (Denmark)

    Hallwyl, Tim; Højsgaard, Espen

    The Web Services Business Process Execution Language (WS-BPEL) is a language for expressing business process behaviour based on web services. The language is intentionally not minimal but provides a rich set of constructs, allows omission of constructs by relying on defaults, and supports language......, does not allow omissions, and does not contain ignorable elements. We do so by identifying syntactic sugar, including default values, and ignorable elements in WS-BPEL. The analysis results in a translation from the full language to the core subset. Thus, we reduce the effort needed for working...

  11. Ceramic core with polymer corona hybrid nanocarrier for the treatment of osteosarcoma with co-delivery of protein and anti-cancer drug

    Science.gov (United States)

    Ram Prasad, S.; Sampath Kumar, T. S.; Jayakrishnan, A.

    2018-01-01

    For the treatment of metastatic bone cancer, local delivery of therapeutic agents is preferred compared to systemic administration. Delivery of an anti-cancer drug and a protein that helps in bone regeneration simultaneously is a challenging approach. In this study, a nanoparticulate carrier which delivers a protein and an anti-cancer drug is reported. Bovine serum albumin (BSA) as a model protein was loaded into hydroxyapatite (HA) nanoparticles (NPs) and methotrexate (MTX) conjugated to poly(vinyl alcohol) was coated onto BSA-loaded HA NPs. Coating efficiency was in the range of 10-17 wt%. In vitro drug release showed that there was a steady increase in the release of both BSA and MTX with 76% of BSA and 88% of MTX being released in 13 days. Cytotoxicity studies of the NPs performed using human osteosarcoma (OMG-63) cell line showed the NPs were highly biocompatible and exhibited anti-proliferative activity in a concentration-dependent manner.

  12. Core labeling of adenovirus with EGFP

    International Nuclear Information System (INIS)

    Le, Long P.; Le, Helen N.; Nelson, Amy R.; Matthews, David A.; Yamamoto, Masato; Curiel, David T.

    2006-01-01

    The study of adenovirus could greatly benefit from diverse methods of virus detection. Recently, it has been demonstrated that carboxy-terminal EGFP fusions of adenovirus core proteins Mu, V, and VII properly localize to the nucleus and display novel function in the cell. Based on these observations, we hypothesized that the core proteins may serve as targets for labeling the adenovirus core with fluorescent proteins. To this end, we constructed various chimeric expression vectors with fusion core genes (Mu-EGFP, V-EGFP, preVII-EGFP, and matVII-EGFP) while maintaining expression of the native proteins. Expression of the fusion core proteins was suboptimal using E1 expression vectors with both conventional CMV and modified (with adenovirus tripartite leader sequence) CMV5 promoters, resulting in non-labeled viral particles. However, robust expression equivalent to the native protein was observed when the fusion genes were placed in the deleted E3 region. The efficient Ad-wt-E3-V-EGFP and Ad-wt-E3-preVII-EGFP expression vectors were labeled allowing visualization of purified virus and tracking of the viral core during early infection. The vectors maintained their viral function, including viral DNA replication, viral DNA encapsidation, cytopathic effect, and thermostability. Core labeling offers a means to track the adenovirus core in vector targeting studies as well as basic adenovirus virology

  13. The effect of point mutations within the N-terminal domain of Mason-Pfizer monkey virus capsid protein on virus core assembly and infectivity

    Czech Academy of Sciences Publication Activity Database

    Wildová, Marcela; Hadravová, Romana; Štokrová, Jitka; Křížová, Ivana; Ruml, Tomáš; Hunter, E.; Pichová, Iva; Rumlová, Michaela

    2008-01-01

    Roč. 380, č. 1 (2008), s. 157-163 ISSN 0042-6822 R&D Projects: GA MŠk 1M0508; GA ČR GESCO/06/E001; GA AV ČR KAN200200651 Grant - others:GA MŠk(CZ) 1M0520 Program:1M Institutional research plan: CEZ:AV0Z40550506 Keywords : caspid protein * assembly * M-PMV Subject RIV: CE - Biochemistry Impact factor: 3.539, year: 2008

  14. Hypothesis review: are clathrin-mediated endocytosis and clathrin-dependent membrane and protein trafficking core pathophysiological processes in schizophrenia and bipolar disorder?

    LENUS (Irish Health Repository)

    2012-02-01

    Clathrin-mediated endocytosis (CME) is the best-characterized mechanism governing cellular membrane and protein trafficking. In this hypothesis review, we integrate recent evidence implicating CME and related cellular trafficking mechanisms in the pathophysiology of psychotic disorders such as schizophrenia and bipolar disorder. The evidence includes proteomic and genomic findings implicating proteins and genes of the clathrin interactome. Additionally, several important candidate genes for schizophrenia, such as dysbindin, are involved in processes closely linked to CME and membrane trafficking. We discuss that key aspects of psychosis neuropathology such as synaptic dysfunction, white matter changes and aberrant neurodevelopment are all influenced by clathrin-dependent processes, and that other cellular trafficking mechanisms previously linked to psychoses interact with the clathrin interactome in important ways. Furthermore, many antipsychotic drugs have been shown to affect clathrin-interacting proteins. We propose that the targeted pharmacological manipulation of the clathrin interactome may offer fruitful opportunities for novel treatments of schizophrenia.Molecular Psychiatry advance online publication, 11 October 2011; doi:10.1038\\/mp.2011.123.

  15. Tandem assays of protein and glucose with functionalized core/shell particles based on magnetic separation and surface-enhanced Raman scattering.

    Science.gov (United States)

    Kong, Xianming; Yu, Qian; Lv, Zhongpeng; Du, Xuezhong

    2013-10-11

    Tandem assays of protein and glucose in combination with mannose-functionalized Fe3 O4 @SiO2 and Ag@SiO2 tag particles have promising potential in effective magnetic separation and highly sensitive and selective SERS assays of biomaterials. It is for the first time that tandem assay of glucose is developed using SERS based on the Con A-sandwiched microstructures between the functionalized magnetic and tag particles. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Protein-stabilized fluorescent nanocrystals consisting of a gold core and a silver shell for detecting the total amount of cysteine and homocysteine

    International Nuclear Information System (INIS)

    Gui, Rijun; Wang, Yanfeng; Sun, Jie

    2014-01-01

    We report on a simple and sensitive method for the determination of the total amount of cysteine (Cys) and homocysteine (hCys), [Cys plus hCys], by exploiting the effect of Cys and hCys on the photoluminescence of human serum albumin-stabilized gold-core silver-shell nanocrystals (NCs). If Cys (or hCys) are added to these NCs, Cys (or hCys) will be adsorbed on the surface due to ligand exchange with human serum albumin, and this results in the quenching of the luminescence of the NCs. The addition of mixtures of Cys and hCys in different molar ratios also induces a decrease in luminescence whose intensity is linearly related to the concentration of [Cys plus hCys] in the range from 0.1 – 5.0 μM, with a correlation coefficient (R 2 ) of 0.9953 and a detection limit of 15 nM. The method is highly selective and sensitive over other α-amino acids, water-soluble thiols, and biomolecules. It has been successfully applied to the determination of the concentration of [Cys plus hCys] in spiked solutions of biomolecules and in real biological samples (author)

  17. Side core lifter

    Energy Technology Data Exchange (ETDEWEB)

    Edelman, Ya A

    1982-01-01

    A side core lifter is proposed which contains a housing with guide slits and a removable core lifter with side projections on the support section connected to the core receiver. In order to preserve the structure of the rock in the core sample by means of guaranteeing rectilinear movement of the core lifter in the rock, the support and core receiver sections are hinged. The device is equipped with a spring for angular shift in the core-reception part.

  18. Broadening of the T-cell repertoire to HIV-1 Gag p24 by vaccination of HLA-A2/DR transgenic mice with overlapping peptides in the CAF05 adjuvant

    DEFF Research Database (Denmark)

    Korsholm, Karen S; Karlsson, Ingrid; Tang, Sheila T

    2013-01-01

    Induction of broad T-cell immune responses is regarded as critical for vaccines against the human immunodeficiency virus type 1 (HIV-1) which exhibit high diversity and, therefore, focus has been on inducing cytotoxic CD8 T-cell responses against the more conserved parts of the virus, such as the....../DR-transgenic mouse model. Thus, combining overlapping Gag p24 peptides with CAF05 appears to be a promising and simple strategy for inducing broader T-cell responses to multiple conserved epitopes which will be relevant for both prophylactic and therapeutic HIV-1 vaccines....

  19. In vivo roles of BamA, BamB and BamD in the biogenesis of BamA, a core protein of the β-barrel assembly machine of Escherichia coli

    Science.gov (United States)

    Misra, Rajeev; Stikeleather, Ryan; Gabriele, Rebecca

    2014-01-01

    Assembly of the β-barrel outer membrane proteins (OMPs) is an essential cellular process in Gram negative bacteria and in the mitochondria and chloroplasts of eukaryotes—two organelles of bacterial origin. Central to this process is the conserved β-barrel OMP that belongs to the Omp85 superfamily. In Escherichia coli, BamA is the core β-barrel OMP, and together with four outer membrane lipoproteins, BamBCDE, constitute the β-barrel assembly machine (BAM). In this paper, we investigated the roles of BamD, an essential lipoprotein, and BamB in BamA biogenesis. Depletion of BamD caused impairment in BamA biogenesis and cessation of cell growth. These defects of BamD depletion were partly reversed by single amino acid substitutions mapping within the β-barrel domain of BamA. However, in the absence of BamB, the positive effects of the β-barrel substitutions on BamA biogenesis under BamD depletion conditions were nullified. By employing a BamA protein bearing one such substitution, F494L, it was demonstrated that the mutant BamA protein could not only assemble without BamD, but it could also facilitate the assembly of wild-type BamA expressed in trans. Based on these data, we propose a model in which the Bam lipoproteins, which are localized to the outer membrane by the BAM-independent Lol pathway, aid in the creation of new BAM complexes by serving as outer membrane receptors and folding factors for nascent BamA molecules. The newly assembled BAM holocomplex then catalyzes the assembly of substrate OMPs and BamA. These in vivo findings are corroborated by recently published in vitro data. PMID:24792419

  20. In vivo roles of BamA, BamB and BamD in the biogenesis of BamA, a core protein of the β-barrel assembly machine of Escherichia coli.

    Science.gov (United States)

    Misra, Rajeev; Stikeleather, Ryan; Gabriele, Rebecca

    2015-03-13

    Assembly of the β-barrel outer membrane proteins (OMPs) is an essential cellular process in Gram-negative bacteria and in the mitochondria and chloroplasts of eukaryotes--two organelles of bacterial origin. Central to this process is the conserved β-barrel OMP that belongs to the Omp85 superfamily. In Escherichia coli, BamA is the core β-barrel OMP and, together with four outer membrane lipoproteins, BamBCDE, constitutes the β-barrel assembly machine (BAM). In this paper, we investigated the roles of BamD, an essential lipoprotein, and BamB in BamA biogenesis. Depletion of BamD caused impairment in BamA biogenesis and cessation of cell growth. These defects of BamD depletion were partly reversed by single-amino-acid substitutions mapping within the β-barrel domain of BamA. However, in the absence of BamB, the positive effects of the β-barrel substitutions on BamA biogenesis under BamD depletion conditions were nullified. By employing a BamA protein bearing one such substitution, F474L, it was demonstrated that the mutant BamA protein could not only assemble without BamD but also facilitate the assembly of wild-type BamA expressed in trans. Based on these data, we propose a model in which the Bam lipoproteins, which are localized to the outer membrane by the BAM-independent Lol pathway, aid in the creation of new BAM complexes by serving as outer membrane receptors and folding factors for nascent BamA molecules. The newly assembled BAM holocomplex then catalyzes the assembly of substrate OMPs and BamA. These in vivo findings are corroborated by recently published in vitro data. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. The Heteroaryldihydropyrimidine Bay 38-7690 Induces Hepatitis B Virus Core Protein Aggregates Associated with Promyelocytic Leukemia Nuclear Bodies in Infected Cells.

    Science.gov (United States)

    Huber, Andrew D; Wolf, Jennifer J; Liu, Dandan; Gres, Anna T; Tang, Jing; Boschert, Kelsey N; Puray-Chavez, Maritza N; Pineda, Dallas L; Laughlin, Thomas G; Coonrod, Emily M; Yang, Qiongying; Ji, Juan; Kirby, Karen A; Wang, Zhengqiang; Sarafianos, Stefan G

    2018-04-25

    Heteroaryldihydropyrimidines (HAPs) are compounds that inhibit hepatitis B virus (HBV) replication by modulating viral capsid assembly. While their biophysical effects on capsid assembly in vitro have been previously studied, the effect of HAP treatment on capsid protein (Cp) in individual HBV-infected cells remains unknown. We report here that the HAP Bay 38-7690 promotes aggregation of recombinant Cp in vitro and causes a time- and dose-dependent decrease of Cp in infected cells, consistent with previously studied HAPs. Interestingly, immunofluorescence analysis showed Cp aggregating in nuclear foci of Bay 38-7690-treated infected cells in a time- and dose-dependent manner. We found these foci to be associated with promyelocytic leukemia (PML) nuclear bodies (NBs), which are structures that affect many cellular functions, including DNA damage response, transcription, apoptosis, and antiviral responses. Cp aggregation is not an artifact of the cell system used, as it is observed in HBV-expressing HepAD38 cells, in HepG2 cells transfected with an HBV-expressing plasmid, and in HepG2-NTCP cells infected with HBV. Use of a Cp overexpression vector without HBV sequences shows that aggregation is independent of viral replication, and use of an HBV-expressing plasmid harboring a HAP resistance mutation in Cp abrogated the aggregation, demonstrating that the effect is due to direct compound-Cp interactions. These studies provide novel insight into the effects of HAP-based treatment at a single-cell level. IMPORTANCE Despite the availability of effective vaccines and treatments, HBV remains a significant global health concern, with more than 240 million individuals chronically infected. Current treatments are highly effective at controlling viral replication and disease progression but rarely cure infections. Therefore, much emphasis is being placed on finding therapeutics with new drug targets, such as viral gene expression, covalently closed circular DNA formation and

  2. Dephosphorylation of the Core Clock Protein KaiC in the Cyanobacterial KaiABC Circadian Oscillator Proceeds via an ATP Synthase Mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Egli, Martin; Mori, Tetsuya; Pattanayek, Rekha; Xu, Yao; Qin, Ximing; Johnson, Carl H. (Vanderbilt)

    2014-10-02

    The circadian clock of the cyanobacterium Synechococcus elongatus can be reconstituted in vitro from three proteins, KaiA, KaiB, and KaiC in the presence of ATP, to tick in a temperature-compensated manner. KaiC, the central cog of this oscillator, forms a homohexamer with 12 ATP molecules bound between its N- and C-terminal domains and exhibits unusual properties. Both the N-terminal (CI) and C-terminal (CII) domains harbor ATPase activity, and the subunit interfaces between CII domains are the sites of autokinase and autophosphatase activities. Hydrolysis of ATP correlates with phosphorylation at threonine and serine sites across subunits in an orchestrated manner, such that first T432 and then S431 are phosphorylated, followed by dephosphorylation of these residues in the same order. Although structural work has provided insight into the mechanisms of ATPase and kinase, the location and mechanism of the phosphatase have remained enigmatic. From the available experimental data based on a range of approaches, including KaiC crystal structures and small-angle X-ray scattering models, metal ion dependence, site-directed mutagenesis (i.e., E318, the general base), and measurements of the associated clock periods, phosphorylation patterns, and dephosphorylation courses as well as a lack of sequence motifs in KaiC that are typically associated with known phosphatases, we hypothesized that KaiCII makes use of the same active site for phosphorylation and dephosphorlyation. We observed that wild-type KaiC (wt-KaiC) exhibits an ATP synthase activity that is significantly reduced in the T432A/S431A mutant. We interpret the first observation as evidence that KaiCII is a phosphotransferase instead of a phosphatase and the second that the enzyme is capable of generating ATP, both from ADP and P{sub i} (in a reversal of the ATPase reaction) and from ADP and P-T432/P-S431 (dephosphorylation). This new concept regarding the mechanism of dephosphorylation is also supported by the

  3. Animal MRI Core

    Data.gov (United States)

    Federal Laboratory Consortium — The Animal Magnetic Resonance Imaging (MRI) Core develops and optimizes MRI methods for cardiovascular imaging of mice and rats. The Core provides imaging expertise,...

  4. Study of the peptide length and amino acid specific substitution in the antigenic activity of the chimeric synthetic peptides, containing the p19 core and gp46 envelope proteins of the HTLV-I virus.

    Science.gov (United States)

    Marin, Milenen Hernández; Rodríguez-Tanty, Chryslaine; Higginson-Clarke, David; Bocalandro, Yadaris Márquez; Peña, Lilliam Pozo

    2005-10-28

    Four chimeric synthetic peptides (Q5, Q6, Q7(multiply sign in circle), and Q8(multiply sign in circle)), incorporating immunodominant epitopes of the core p19 (105-124 a.a.) and envelope gp46 proteins (175-205 a.a.), of HTLV-I were obtained. Also, two gp46 monomeric peptides M4 and M5(multiply sign in circle) (Ser at position 192) were synthesized. The analysis of the influence of the peptide lengths and the proline to serine substitution on the chimeric and monomeric peptides' antigenicity, with regard to the chimeric peptides Q1, Q2, Q3(multiply sign in circle), and Q4(multiply sign in circle), reported previously, for HTLV-I was carried out. The peptides' antigenicity was evaluated in an ultramicroenzyme-linked immunosorbent assay (UMELISA) using sera of HTLV-I/II. The peptides' antigenicity was affected appreciably by the change of the peptide length and amino acid substitutions into the immunodominant sequence of gp46 peptide.

  5. Core Hunter 3: flexible core subset selection.

    Science.gov (United States)

    De Beukelaer, Herman; Davenport, Guy F; Fack, Veerle

    2018-05-31

    Core collections provide genebank curators and plant breeders a way to reduce size of their collections and populations, while minimizing impact on genetic diversity and allele frequency. Many methods have been proposed to generate core collections, often using distance metrics to quantify the similarity of two accessions, based on genetic marker data or phenotypic traits. Core Hunter is a multi-purpose core subset selection tool that uses local search algorithms to generate subsets relying on one or more metrics, including several distance metrics and allelic richness. In version 3 of Core Hunter (CH3) we have incorporated two new, improved methods for summarizing distances to quantify diversity or representativeness of the core collection. A comparison of CH3 and Core Hunter 2 (CH2) showed that these new metrics can be effectively optimized with less complex algorithms, as compared to those used in CH2. CH3 is more effective at maximizing the improved diversity metric than CH2, still ensures a high average and minimum distance, and is faster for large datasets. Using CH3, a simple stochastic hill-climber is able to find highly diverse core collections, and the more advanced parallel tempering algorithm further increases the quality of the core and further reduces variability across independent samples. We also evaluate the ability of CH3 to simultaneously maximize diversity, and either representativeness or allelic richness, and compare the results with those of the GDOpt and SimEli methods. CH3 can sample equally representative cores as GDOpt, which was specifically designed for this purpose, and is able to construct cores that are simultaneously more diverse, and either are more representative or have higher allelic richness, than those obtained by SimEli. In version 3, Core Hunter has been updated to include two new core subset selection metrics that construct cores for representativeness or diversity, with improved performance. It combines and outperforms the

  6. k-core covers and the core

    NARCIS (Netherlands)

    Sanchez-Rodriguez, E.; Borm, Peter; Estevez-Fernandez, A.; Fiestras-Janeiro, G.; Mosquera, M.A.

    This paper extends the notion of individual minimal rights for a transferable utility game (TU-game) to coalitional minimal rights using minimal balanced families of a specific type, thus defining a corresponding minimal rights game. It is shown that the core of a TU-game coincides with the core of

  7. Reactor core fuel management

    International Nuclear Information System (INIS)

    Silvennoinen, P.

    1976-01-01

    The subject is covered in chapters, entitled: concepts of reactor physics; neutron diffusion; core heat transfer; reactivity; reactor operation; variables of core management; computer code modules; alternative reactor concepts; methods of optimization; general system aspects. (U.K.)

  8. Nuclear reactor core catcher

    International Nuclear Information System (INIS)

    1977-01-01

    A nuclear reactor core catcher is described for containing debris resulting from an accident causing core meltdown and which incorporates a method of cooling the debris by the circulation of a liquid coolant. (U.K.)

  9. Seismic core shroud

    International Nuclear Information System (INIS)

    Puri, A.; Mullooly, J.F.

    1981-01-01

    A core shroud is provided, comprising: a coolant boundary, following the shape of the core boundary, for channeling the coolant through the fuel assemblies; a cylindrical band positioned inside the core barrel and surrounding the coolant boundary; and support members extending from the coolant boundary to the band, for transferring load from the coolant boundary to the band. The shroud may be assembled in parts using automated welding techniques, and it may be adjusted to fit the reactor core easily

  10. Core Values | NREL

    Science.gov (United States)

    Core Values Core Values NREL's core values are rooted in a safe and supportive work environment guide our everyday actions and efforts: Safe and supportive work environment Respect for the rights physical and social environment Integrity Maintain the highest standard of ethics, honesty, and integrity

  11. Sidewall coring shell

    Energy Technology Data Exchange (ETDEWEB)

    Edelman, Ya A; Konstantinov, L P; Martyshin, A N

    1966-12-12

    A sidewall coring shell consists of a housing and a detachable core catcher. The core lifter is provided with projections, the ends of which are situated in another plane, along the longitudinal axis of the lifter. The chamber has corresponding projections.

  12. Rotary core drills

    Energy Technology Data Exchange (ETDEWEB)

    1967-11-30

    The design of a rotary core drill is described. Primary consideration is given to the following component parts of the drill: the inner and outer tube, the core bit, an adapter, and the core lifter. The adapter has the form of a downward-converging sleeve and is mounted to the lower end of the inner tube. The lifter, extending from the adapter, is split along each side so that it can be held open to permit movement of a core. It is possible to grip a core by allowing the lifter to assume a closed position.

  13. HYDRATE CORE DRILLING TESTS

    Energy Technology Data Exchange (ETDEWEB)

    John H. Cohen; Thomas E. Williams; Ali G. Kadaster; Bill V. Liddell

    2002-11-01

    The ''Methane Hydrate Production from Alaskan Permafrost'' project is a three-year endeavor being conducted by Maurer Technology Inc. (MTI), Noble, and Anadarko Petroleum, in partnership with the U.S. DOE National Energy Technology Laboratory (NETL). The project's goal is to build on previous and ongoing R&D in the area of onshore hydrate deposition. The project team plans to design and implement a program to safely and economically drill, core and produce gas from arctic hydrates. The current work scope includes drilling and coring one well on Anadarko leases in FY 2003 during the winter drilling season. A specially built on-site core analysis laboratory will be used to determine some of the physical characteristics of the hydrates and surrounding rock. Prior to going to the field, the project team designed and conducted a controlled series of coring tests for simulating coring of hydrate formations. A variety of equipment and procedures were tested and modified to develop a practical solution for this special application. This Topical Report summarizes these coring tests. A special facility was designed and installed at MTI's Drilling Research Center (DRC) in Houston and used to conduct coring tests. Equipment and procedures were tested by cutting cores from frozen mixtures of sand and water supported by casing and designed to simulate hydrate formations. Tests were conducted with chilled drilling fluids. Tests showed that frozen core can be washed out and reduced in size by the action of the drilling fluid. Washing of the core by the drilling fluid caused a reduction in core diameter, making core recovery very difficult (if not impossible). One successful solution was to drill the last 6 inches of core dry (without fluid circulation). These tests demonstrated that it will be difficult to capture core when drilling in permafrost or hydrates without implementing certain safeguards. Among the coring tests was a simulated hydrate

  14. Core binding factor beta (Cbfβ) controls the balance of chondrocyte proliferation and differentiation by upregulating Indian hedgehog (Ihh) expression and inhibiting parathyroid hormone-related protein receptor (PPR) expression in postnatal cartilage and bone formation.

    Science.gov (United States)

    Tian, Fei; Wu, Mengrui; Deng, Lianfu; Zhu, Guochun; Ma, Junqing; Gao, Bo; Wang, Lin; Li, Yi-Ping; Chen, Wei

    2014-07-01

    Core binding factor beta (Cbfβ) is essential for embryonic bone morphogenesis. Yet the mechanisms by which Cbfβ regulates chondrocyte proliferation and differentiation as well as postnatal cartilage and bone formation remain unclear. Hence, using paired-related homeobox transcription factor 1-Cre (Prx1-Cre) mice, mesenchymal stem cell-specific Cbfβ-deficient (Cbfβ(f/f) Prx1-Cre) mice were generated to study the role of Cbfβ in postnatal cartilage and bone development. These mutant mice survived to adulthood but exhibited severe sternum and limb malformations. Sternum ossification was largely delayed in the Cbfβ(f/f) Prx1-Cre mice and the xiphoid process was noncalcified and enlarged. In newborn and 7-day-old Cbfβ(f/f) Prx1-Cre mice, the resting zone was dramatically elongated, the proliferation zone and hypertrophic zone of the growth plates were drastically shortened and disorganized, and trabecular bone formation was reduced. Moreover, in 1-month-old Cbfβ(f/f) Prx1-Cre mice, the growth plates were severely deformed and trabecular bone was almost absent. In addition, Cbfβ deficiency impaired intramembranous bone formation both in vivo and in vitro. Interestingly, although the expression of Indian hedgehog (Ihh) was largely reduced, the expression of parathyroid hormone-related protein (PTHrP) receptor (PPR) was dramatically increased in the Cbfβ(f/f) Prx1-Cre growth plate, indicating that that Cbfβ deficiency disrupted the Ihh-PTHrP negative regulatory loop. Chromatin immunoprecipitation (ChIP) analysis and promoter luciferase assay demonstrated that the Runx/Cbfβ complex binds putative Runx-binding sites of the Ihh promoter regions, and also the Runx/Cbfβ complex directly upregulates Ihh expression at the transcriptional level. Consistently, the expressions of Ihh target genes, including CyclinD1, Ptc, and Pthlh, were downregulated in Cbfβ-deficient chondrocytes. Taken together, our study reveals not only that Cbfβ is essential for chondrocyte

  15. On the violation of the exponential decay law in atomic physics: ab initio calculation of the time-dependence of the He-1s2p24P non-stationary state

    International Nuclear Information System (INIS)

    Nicolaides, C.A.; Mercouris, T.

    1996-01-01

    The detailed time dependence of the decay of a three-electron autoionizing state close to threshold has been obtained ab initio by solving the time-dependent Schrodinger equation (TDSE). The theory allows the definition and computation of energy-dependent matrix elements in terms of the appropriate N-electron wavefunctions, representing the localized initial state, Ψ O , the stationary scattering states of the continuous spectrum, U( e psilon ) , and the localized excited states, Ψ n , of the effective Hamiltonian QHQ, where Q ''ident to'' |Ψ O > O |. The time-dependent wavefunction is expanded over these states and the resulting coupled equations with time-dependent coefficients (in the thousands) are solved to all orders by a Taylor series expansion technique. The robustness of the method was verified by using a model interaction in analytic form and comparing the results from two different methods for integrating the TDSE (appendix B). For the physically relevant application, the chosen state was the He - 1s2p 24 P shape resonance, about which very accurate theoretical and experimental relevant information exists. Calculations using accurate wavefunctions and an energy grid of 20.000 points in the range 0.0-21.77 eV show that the effective interaction depends on energy in a state-specific manner, thereby leading to state-specific characteristics of non-exponential decay over about 6 x 10 4 au of time, from which a width of Γ = 5.2 meV and a lifetime of 1.26 x 10 -13 s is deduced. The results suggest that either in this state or in other autoionizing states close to threshold, NED may have sufficient presence to make the violation of the law of exponential decay observable. (Author)

  16. The core paradox.

    Science.gov (United States)

    Kennedy, G. C.; Higgins, G. H.

    1973-01-01

    Rebuttal of suggestions from various critics attempting to provide an escape from the seeming paradox originated by Higgins and Kennedy's (1971) proposed possibility that the liquid in the outer core was thermally stably stratified and that this stratification might prove a powerful inhibitor to circulation of the outer core fluid of the kind postulated for the generation of the earth's magnetic field. These suggestions are examined and shown to provide no reasonable escape from the core paradox.

  17. Nuclear reactor core flow baffling

    International Nuclear Information System (INIS)

    Berringer, R.T.

    1979-01-01

    A flow baffling arrangement is disclosed for the core of a nuclear reactor. A plurality of core formers are aligned with the grids of the core fuel assemblies such that the high pressure drop areas in the core are at the same elevations as the high pressure drop areas about the core periphery. The arrangement minimizes core bypass flow, maintains cooling of the structure surrounding the core, and allows the utilization of alternative beneficial components such as neutron reflectors positioned near the core

  18. Sediment Core Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Provides instrumentation and expertise for physical and geoacoustic characterization of marine sediments.DESCRIPTION: The multisensor core logger measures...

  19. Can Psychiatric Rehabilitation Be Core to CORE?

    Science.gov (United States)

    Olney, Marjorie F.; Gill, Kenneth J.

    2016-01-01

    Purpose: In this article, we seek to determine whether psychiatric rehabilitation principles and practices have been more fully incorporated into the Council on Rehabilitation Education (CORE) standards, the extent to which they are covered in four rehabilitation counseling "foundations" textbooks, and how they are reflected in the…

  20. PWR core design calculations

    International Nuclear Information System (INIS)

    Trkov, A.; Ravnik, M.; Zeleznik, N.

    1992-01-01

    Functional description of the programme package Cord-2 for PWR core design calculations is presented. Programme package is briefly described. Use of the package and calculational procedures for typical core design problems are treated. Comparison of main results with experimental values is presented as part of the verification process. (author) [sl

  1. Replaceable LMFBR core components

    International Nuclear Information System (INIS)

    Evans, E.A.; Cunningham, G.W.

    1976-01-01

    Much progress has been made in understanding material and component performance in the high temperature, fast neutron environment of the LMFBR. Current data have provided strong assurance that the initial core component lifetime objectives of FFTF and CRBR can be met. At the same time, this knowledge translates directly into the need for improved core designs that utilize improved materials and advanced fuels required to meet objectives of low doubling times and extended core component lifetimes. An industrial base for the manufacture of quality core components has been developed in the US, and all procurements for the first two core equivalents for FFTF will be completed this year. However, the problem of fabricating recycled plutonium while dramatically reducing fabrication costs, minimizing personnel exposure, and protecting public health and safety must be addressed

  2. Lunar Core and Tides

    Science.gov (United States)

    Williams, J. G.; Boggs, D. H.; Ratcliff, J. T.

    2004-01-01

    Variations in rotation and orientation of the Moon are sensitive to solid-body tidal dissipation, dissipation due to relative motion at the fluid-core/solid-mantle boundary, and tidal Love number k2 [1,2]. There is weaker sensitivity to flattening of the core-mantle boundary (CMB) [2,3,4] and fluid core moment of inertia [1]. Accurate Lunar Laser Ranging (LLR) measurements of the distance from observatories on the Earth to four retroreflector arrays on the Moon are sensitive to lunar rotation and orientation variations and tidal displacements. Past solutions using the LLR data have given results for dissipation due to solid-body tides and fluid core [1] plus Love number [1-5]. Detection of CMB flattening, which in the past has been marginal but improving [3,4,5], now seems significant. Direct detection of the core moment has not yet been achieved.

  3. Internal core tightener

    International Nuclear Information System (INIS)

    Brynsvold, G.V.; Snyder, H.J. Jr.

    1976-01-01

    An internal core tightener is disclosed which is a linear actuated (vertical actuation motion) expanding device utilizing a minimum of moving parts to perform the lateral tightening function. The key features are: (1) large contact areas to transmit loads during reactor operation; (2) actuation cam surfaces loaded only during clamping and unclamping operation; (3) separation of the parts and internal operation involved in the holding function from those involved in the actuation function; and (4) preloaded pads with compliant travel at each face of the hexagonal assembly at the two clamping planes to accommodate thermal expansion and irradiation induced swelling. The latter feature enables use of a ''fixed'' outer core boundary, and thus eliminates the uncertainty in gross core dimensions, and potential for rapid core reactivity changes as a result of core dimensional change. 5 claims, 12 drawing figures

  4. Method for manufacturing carrier containing e.g. proteins for human during oral drug delivery operation for food and drug administration application in pharmaceutical industry, involves providing active ingredient to core layer

    DEFF Research Database (Denmark)

    2015-01-01

    NOVELTY - The method involves preparing a multi-layered film comprising a core layer and a barrier layer, where the core layer comprises active ingredient. The multi-layered film is subjected to a hot embossing step using an embossing stamp including protrusions that allows for generation...... delivery operation for a food and drug administration (FDA) application in a pharmaceutical industry. ADVANTAGE - The method enables allowing an individual micro-structure stuck in an embossing stamp to be demolded under the conditions such that demolding operation is done by treating elastically...

  5. s-core network decomposition: A generalization of k-core analysis to weighted networks

    Science.gov (United States)

    Eidsaa, Marius; Almaas, Eivind

    2013-12-01

    A broad range of systems spanning biology, technology, and social phenomena may be represented and analyzed as complex networks. Recent studies of such networks using k-core decomposition have uncovered groups of nodes that play important roles. Here, we present s-core analysis, a generalization of k-core (or k-shell) analysis to complex networks where the links have different strengths or weights. We demonstrate the s-core decomposition approach on two random networks (ER and configuration model with scale-free degree distribution) where the link weights are (i) random, (ii) correlated, and (iii) anticorrelated with the node degrees. Finally, we apply the s-core decomposition approach to the protein-interaction network of the yeast Saccharomyces cerevisiae in the context of two gene-expression experiments: oxidative stress in response to cumene hydroperoxide (CHP), and fermentation stress response (FSR). We find that the innermost s-cores are (i) different from innermost k-cores, (ii) different for the two stress conditions CHP and FSR, and (iii) enriched with proteins whose biological functions give insight into how yeast manages these specific stresses.

  6. Earth's inner core: Innermost inner core or hemispherical variations?

    NARCIS (Netherlands)

    Lythgoe, K. H.; Deuss, A.|info:eu-repo/dai/nl/412396610; Rudge, J. F.; Neufeld, J. A.

    2014-01-01

    The structure of Earth's deep inner core has important implications for core evolution, since it is thought to be related to the early stages of core formation. Previous studies have suggested that there exists an innermost inner core with distinct anisotropy relative to the rest of the inner core.

  7. Dependence of Core and Extended Flux on Core Dominance ...

    Indian Academy of Sciences (India)

    Abstract. Based on two extragalactic radio source samples, the core dominance parameter is calculated, and the correlations between the core/extended flux density and core dominance parameter are investi- gated. When the core dominance parameter is lower than unity, it is linearly correlated with the core flux density, ...

  8. Korrelasjon mellom core styrke, core stabilitet og utholdende styrke i core

    OpenAIRE

    Berg-Olsen, Andrea Marie; Fugelsøy, Eivor; Maurstad, Ann-Louise

    2010-01-01

    Formålet med studien var å se hvilke korrelasjon det er mellom core styrke, core stabilitet og utholdende styrke i core. Testingen bestod av tre hoveddeler hvor vi testet core styrke, core stabilitet og utholdende styrke i core. Innenfor core styrke og utholdende styrke i core ble tre ulike tester utført. Ved måling av core stabilitet ble det gjennomført kun en test. I core styrke ble isometrisk abdominal fleksjon, isometrisk rygg ekstensjon og isometrisk lateral fleksjon testet. Sit-ups p...

  9. Windscale pile core surveys

    International Nuclear Information System (INIS)

    Curtis, R.F.; Mathews, R.F.

    1996-01-01

    The two Windscale Piles were closed down, defueled as far as possible and mothballed for thirty years following a fire in the core of Pile 1 in 1957 resulting from the spontaneous release of stored Wigner energy in the graphite moderator. Decommissioning of the reactors commenced in 1987 and has reached the stage where the condition of both cores needs to be determined. To this end, non-intrusive and intrusive surveys and sampling of the cores have been planned and partly implemented. The objectives for each Pile differ slightly. The location and quantity of fuel remaining in the damaged core of Pile 1 needed to be established, whereas the removal of all fuel from Pile 2 needed to be confirmed. In Pile 1, the possible existence of a void in the core is to be explored and in Pile 2, the level of Wigner energy remaining required to be quantified. Levels of radioactivity in both cores needed to be measured. The planning of the surveys is described including strategy, design, safety case preparation and the remote handling and viewing equipment required to carry out the inspection, sampling and monitoring work. The results from the completed non-intrusive survey of Pile 2 are summarised. They confirm that the core is empty and the graphite is in good condition. The survey of Pile 1 has just started. (UK)

  10. Core shroud corner joints

    Science.gov (United States)

    Gilmore, Charles B.; Forsyth, David R.

    2013-09-10

    A core shroud is provided, which includes a number of planar members, a number of unitary corners, and a number of subassemblies each comprising a combination of the planar members and the unitary corners. Each unitary corner comprises a unitary extrusion including a first planar portion and a second planar portion disposed perpendicularly with respect to the first planar portion. At least one of the subassemblies comprises a plurality of the unitary corners disposed side-by-side in an alternating opposing relationship. A plurality of the subassemblies can be combined to form a quarter perimeter segment of the core shroud. Four quarter perimeter segments join together to form the core shroud.

  11. IGCSE core mathematics

    CERN Document Server

    Wall, Terry

    2013-01-01

    Give your core level students the support and framework they require to get their best grades with this book dedicated to the core level content of the revised syllabus and written specifically to ensure a more appropriate pace. This title has been written for Core content of the revised Cambridge IGCSE Mathematics (0580) syllabus for first teaching from 2013. ? Gives students the practice they require to deepen their understanding through plenty of practice questions. ? Consolidates learning with unique digital resources on the CD, included free with every book. We are working with Cambridge

  12. Heterogeneous gas core reactor

    International Nuclear Information System (INIS)

    Diaz, N.J.; Dugan, E.T.

    1983-01-01

    A heterogeneous gas core nuclear reactor is disclosed comprising a core barrel provided interiorly with an array of moderator-containing tubes and being otherwise filled with a fissile and/or fertile gaseous fuel medium. The fuel medium may be flowed through the chamber and through an external circuit in which heat is extracted. The moderator may be a fluid which is flowed through the tubes and through an external circuit in which heat is extracted. The moderator may be a solid which may be cooled by a fluid flowing within the tubes and through an external heat extraction circuit. The core barrel is surrounded by moderator/coolant material. Fissionable blanket material may be disposed inwardly or outwardly of the core barrel

  13. iPSC Core

    Data.gov (United States)

    Federal Laboratory Consortium — The induced Pluripotent Stem Cells (iPSC) Core was created in 2011 to accelerate stem cell research in the NHLBI by providing investigators consultation, technical...

  14. Core Flight Software

    Data.gov (United States)

    National Aeronautics and Space Administration — The AES Core Flight Software (CFS) project purpose is to analyze applicability, and evolve and extend the reusability of the CFS system originally developed by...

  15. PWR degraded core analysis

    International Nuclear Information System (INIS)

    Gittus, J.H.

    1982-04-01

    A review is presented of the various phenomena involved in degraded core accidents and the ensuing transport of fission products from the fuel to the primary circuit and the containment. The dominant accident sequences found in the PWR risk studies published to date are briefly described. Then chapters deal with the following topics: the condition and behaviour of water reactor fuel during normal operation and at the commencement of degraded core accidents; the generation of hydrogen from the Zircaloy-steam and the steel-steam reactions; the way in which the core deforms and finally melts following loss of coolant; debris relocation analysis; containment integrity; fission product behaviour during a degraded core accident. (U.K.)

  16. Restraint system for core elements of a reactor core

    International Nuclear Information System (INIS)

    Class, G.

    1975-01-01

    In a nuclear reactor, a core element bundle formed of a plurality of side-by-side arranged core elements is surrounded by restraining elements that exert a radially inwardly directly restraining force generating friction forces between the core elements in a restraining plane that is transverse to the core element axes. The adjoining core elements are in rolling contact with one another in the restraining plane by virtue of rolling-type bearing elements supported in the core elements. (Official Gazette)

  17. Heterogeneous gas core reactor

    International Nuclear Information System (INIS)

    Han, K.I.

    1977-01-01

    Preliminary investigations of a heterogeneous gas core reactor (HGCR) concept suggest that this potential power reactor offers distinct advantages over other existing or conceptual reactor power plants. One of the most favorable features of the HGCR is the flexibility of the power producing system which allows it to be efficiently designed to conform to a desired optimum condition without major conceptual changes. The arrangement of bundles of moderator/coolant channels in a fissionable gas or mixture of gases makes a truly heterogeneous nuclear reactor core. It is this full heterogeneity for a gas-fueled reactor core which accounts for the novelty of the heterogeneous gas core reactor concept and leads to noted significant advantages over previous gas core systems with respect to neutron and fuel economy, power density, and heat transfer characteristics. The purpose of this work is to provide an insight into the design, operating characteristics, and safety of a heterogeneous gas core reactor system. The studies consist mainly of neutronic, energetic and kinetic analyses of the power producing and conversion systems as a preliminary assessment of the heterogeneous gas core reactor concept and basic design. The results of the conducted research indicate a high potential for the heterogeneous gas core reactor system as an electrical power generating unit (either large or small), with an overall efficiency as high as 40 to 45%. The HGCR system is found to be stable and safe, under the conditions imposed upon the analyses conducted in this work, due to the inherent safety of ann expanding gaseous fuel and the intrinsic feedback effects of the gas and water coolant

  18. FBR type reactor core

    International Nuclear Information System (INIS)

    Tamiya, Tadashi; Kawashima, Katsuyuki; Fujimura, Koji; Murakami, Tomoko.

    1995-01-01

    Neutron reflectors are disposed at the periphery of a reactor core fuel region and a blanket region, and a neutron shielding region is disposed at the periphery of them. The neutron reflector has a hollow duct structure having a sealed upper portion, a lower portion opened to cooling water, in which a gas and coolants separately sealed in the inside thereof. A driving pressure of a primary recycling pump is lowered upon reduction of coolant flow rate, then the liquid level of coolants in the neutron reflector is lowered due to imbalance between the driving pressure and a gas pressure, so that coolants having an effect as a reflector are eliminated from the outer circumference of the reactor core. Therefore, the amount of neutrons leaking from the reactor core is increased, and negative reactivity is charged to the reactor core. The negative reactivity of the neutron reflector is made greater than a power compensation reactivity. Since this enables reactor scram by using an inherent performance of the reactor core, the reactor core safety of an LMFBR-type reactor can be improved. (I.N.)

  19. The earths innermost core

    International Nuclear Information System (INIS)

    Nanda, J.N.

    1989-01-01

    A new earth model is advanced with a solid innermost core at the centre of the Earth where elements heavier than iron, over and above what can be retained in solution in the iron core, are collected. The innermost core is separated from the solid iron-nickel core by a shell of liquid copper. The innermost core has a natural vibration measured on the earth's surface as the long period 26 seconds microseisms. The earth was formed initially as a liquid sphere with a relatively thin solid crust above the Byerly discontinuity. The trace elements that entered the innermost core amounted to only 0.925 ppm of the molten mass. Gravitational differentiation must have led to the separation of an explosive thickness of pure 235 U causing a fission explosion that could expel beyond the Roche limit a crustal scab which would form the centre piece of the moon. A reservoir of helium floats on the liquid copper. A small proportion of helium-3, a relic of the ancient fission explosion present there will spell the exciting magnetic field. The field is stable for thousands of years because of the presence of large quantity of helium-4 which accounts for most of the gaseous collisions that will not disturb the atomic spin of helium-3 atoms. This field is prone to sudden reversals after long periods of stability. (author). 14 refs

  20. Two Novel Rab2 Interactors Regulate Dense-core Vesicle Maturation

    Science.gov (United States)

    Ailion, Michael; Hannemann, Mandy; Dalton, Susan; Pappas, Andrea; Watanabe, Shigeki; Hegermann, Jan; Liu, Qiang; Han, Hsiao-Fen; Gu, Mingyu; Goulding, Morgan Q.; Sasidharan, Nikhil; Schuske, Kim; Hullett, Patrick; Eimer, Stefan; Jorgensen, Erik M.

    2014-01-01

    Summary Peptide neuromodulators are released from a unique organelle: the dense-core vesicle. Dense-core vesicles are generated at the trans-Golgi, and then sort cargo during maturation before being secreted. To identify proteins that act in this pathway, we performed a genetic screen in Caenorhabditis elegans for mutants defective in dense-core vesicle function. We identified two conserved Rab2-binding proteins: RUND-1, a RUN domain protein, and CCCP-1, a coiled-coil protein. RUND-1 and CCCP-1 colocalize with RAB-2 at the Golgi, and rab-2, rund-1 and cccp-1 mutants have similar defects in sorting soluble and transmembrane dense-core vesicle cargos. RUND-1 also interacts with the Rab2 GAP protein TBC-8 and the BAR domain protein RIC-19, a RAB-2 effector. In summary, a new pathway of conserved proteins controls the maturation of dense-core vesicles at the trans-Golgi network. PMID:24698274

  1. Reactor core control device

    International Nuclear Information System (INIS)

    Sano, Hiroki

    1998-01-01

    The present invention provides a reactor core control device, in which switching from a manual operation to an automatic operation, and the control for the parameter of an automatic operation device are facilitated. Namely, the hysteresis of the control for the operation parameter by an manual operation input means is stored. The hysteresis of the control for the operation parameter is collected. The state of the reactor core simulated by an operation control to which the collected operation parameters are manually inputted is determined as an input of the reactor core state to the automatic input means. The record of operation upon manual operation is stored as a hysteresis of control for the operation parameter, but the hysteresis information is not only the result of manual operation of the operation parameter. This is results of operation conducted by a skilled operator who judge the state of the reactor core to be optimum. Accordingly, it involves information relevant to the reactor core state. Then, it is considered that the optimum automatic operation is not deviated greatly from the manual operation. (I.S.)

  2. The PWR cores management

    International Nuclear Information System (INIS)

    Barral, J.C.; Rippert, D.; Johner, J.

    2000-01-01

    During the meeting of the 25 january 2000, organized by the SFEN, scientists and plant operators in the domain of the PWR debated on the PWR cores management. The five first papers propose general and economic information on the PWR and also the fast neutron reactors chains in the electric power market: statistics on the electric power industry, nuclear plant unit management, the ITER project and the future of the thermonuclear fusion, the treasurer's and chairman's reports. A second part offers more technical papers concerning the PWR cores management: performance and optimization, in service load planning, the cores management in the other countries, impacts on the research and development programs. (A.L.B.)

  3. Molten core retention assembly

    International Nuclear Information System (INIS)

    Lampe, R.F.

    1976-01-01

    Molten fuel produced in a core overheating accident is caught by a molten core retention assembly consisting of a horizontal baffle plate having a plurality of openings therein, heat exchange tubes having flow holes near the top thereof mounted in the openings, and a cylindrical imperforate baffle attached to the plate and surrounding the tubes. The baffle assembly is supported from the core support plate of the reactor by a plurality of hanger rods which are welded to radial beams passing under the baffle plate and intermittently welded thereto. Preferably the upper end of the cylindrical baffle terminates in an outwardly facing lip to which are welded a plurality of bearings having slots therein adapted to accept the hanger rods

  4. Core status computing system

    International Nuclear Information System (INIS)

    Yoshida, Hiroyuki.

    1982-01-01

    Purpose: To calculate power distribution, flow rate and the like in the reactor core with high accuracy in a BWR type reactor. Constitution: Total flow rate signals, traverse incore probe (TIP) signals as the neutron detector signals, thermal power signals and pressure signals are inputted into a process computer, where the power distribution and the flow rate distribution in the reactor core are calculated. A function generator connected to the process computer calculates the absolute flow rate passing through optional fuel assemblies using, as variables, flow rate signals from the introduction part for fuel assembly flow rate signals, data signals from the introduction part for the geometrical configuration data at the flow rate measuring site of fuel assemblies, total flow rate signals for the reactor core and the signals from the process computer. Numerical values thus obtained are given to the process computer as correction signals to perform correction for the experimental data. (Moriyama, K.)

  5. TMI-2 core examination

    International Nuclear Information System (INIS)

    Hobbins, R.R.; MacDonald, P.E.; Owen, D.E.

    1983-01-01

    The examination of the damaged core at the Three Mile Island Unit 2 (TMI-2) reactor is structured to address the following safety issues: fission product release, transport, and deposition; core coolability; containment integrity; and recriticality during severe accidents; as well as zircaloy cladding ballooning and oxidation during so-called design basis accidents. The numbers of TMI-2 components or samples to be examined, the priority of each examination, the safety issue addressed by each examination, the principal examination techniques to be employed, and the data to be obtained and the principal uses of the data are discussed in this paper

  6. Superconducting tin core fiber

    International Nuclear Information System (INIS)

    Homa, Daniel; Liang, Yongxuan; Hill, Cary; Kaur, Gurbinder; Pickrell, Gary

    2015-01-01

    In this study, we demonstrated superconductivity in a fiber with a tin core and fused silica cladding. The fibers were fabricated via a modified melt-draw technique and maintained core diameters ranging from 50-300 microns and overall diameters of 125-800 microns. Superconductivity of this fiber design was validated via the traditional four-probe test method in a bath of liquid helium at temperatures on the order of 3.8 K. The synthesis route and fiber design are perquisites to ongoing research dedicated all-fiber optoelectronics and the relationships between superconductivity and the material structures, as well as corresponding fabrication techniques. (orig.)

  7. LMFBR core design analysis

    International Nuclear Information System (INIS)

    Cho, M.; Yang, J.C.; Yoh, K.C.; Suk, S.D.; Soh, D.S.; Kim, Y.M.

    1980-01-01

    The design parameters of a commercial-scale fast breeder reactor which is currently under construction by regeneration of these data is preliminary analyzed. The analysis of nuclear and thermal characteristics as well as safety features of this reactor is emphasized. And the evaluation of the initial core mentioned in the system description is carried out in the areas of its kinetics and control system, and, at the same time, the flow distribution of sodium and temperature distribution of the initial FBR core system are calculated. (KAERI INIS Section)

  8. Nuclear core catchers

    International Nuclear Information System (INIS)

    Golden, M.P.; Tilbrook, R.W.; Heylmun, N.F.

    1976-01-01

    A receptacle is described for taking the molten fragments of a nuclear reactor during a reactor core fusion accident. The receptacle is placed under the reactor. It includes at least one receptacle for the reactor core fragments, with a dome shaped part to distribute the molten fragments and at least one outside layer of alumina bricks around the dome. The characteristic of this receptacle is that the outer layer of bricks contains neutron poison rods which pass through the bricks and protrude in relation to them [fr

  9. Organizing Core Tasks

    DEFF Research Database (Denmark)

    Boll, Karen

    has remained much the same within the last 10 years. However, how the core task has been organized has changed considerable under the influence of various “organizing devices”. The paper focusses on how organizing devices such as risk assessment, output-focus, effect orientation, and treatment...... projects influence the organization of core tasks within the tax administration. The paper shows that the organizational transformations based on the use of these devices have had consequences both for the overall collection of revenue and for the employees’ feeling of “making a difference”. All in all...

  10. GREEN CORE HOUSE

    Directory of Open Access Journals (Sweden)

    NECULAI Oana

    2017-05-01

    Full Text Available The Green Core House is a construction concept with low environmental impact, having as main central element a greenhouse. The greenhouse has the innovative role to use the biomass energy provided by plants to save energy. Although it is the central piece, the greenhouse is not the most innovative part of the Green Core House, but the whole building ensemble because it integrates many other sustainable systems as "waste purification systems", "transparent photovoltaic panels" or "double skin façades".

  11. PWR core design calculations

    Energy Technology Data Exchange (ETDEWEB)

    Trkov, A; Ravnik, M; Zeleznik, N [Inst. Jozef Stefan, Ljubljana (Slovenia)

    1992-07-01

    Functional description of the programme package Cord-2 for PWR core design calculations is presented. Programme package is briefly described. Use of the package and calculational procedures for typical core design problems are treated. Comparison of main results with experimental values is presented as part of the verification process. (author) [Slovenian] Opisali smo programski paket CORD-2, ki se uporablja pri projektnih izracunih sredice pri upravljanju tlacnovodnega reaktorja. Prikazana je uporaba paketa in racunskih postopkov za tipicne probleme, ki nastopajo pri projektiranju sredice. Primerjava glavnih rezultatov z eksperimentalnimi vrednostmi je predstavljena kot del preveritvenega procesa. (author)

  12. Maximum stellar iron core mass

    Indian Academy of Sciences (India)

    An analytical method of estimating the mass of a stellar iron core, just prior to core collapse, is described in this paper. The method employed depends, in part, upon an estimate of the true relativistic mass increase experienced by electrons within a highly compressed iron core, just prior to core collapse, and is significantly ...

  13. Nuclear core baffling apparatus

    International Nuclear Information System (INIS)

    Cooper, F.W. Jr.; Silverblatt, B.L.; Knight, C.B.; Berringer, R.T.

    1979-01-01

    An apparatus for baffling the flow of reactor coolant fluid into and about the core of a nuclear reactor is described. The apparatus includes a plurality of longitudinally aligned baffle plates with mating surfaces that allow longitudinal growth with temperature increases while alleviating both leakage through the aligned plates and stresses on the components supporting the plates

  14. The Uncommon Core

    Science.gov (United States)

    Ohler, Jason

    2013-01-01

    This author contends that the United States neglects creativity in its education system. To see this, he states, one may look at the Common Core State Standards. If one searches the English Language Arts and Literacy standards for the words "creative," "innovative," and "original"--and any associated terms, one will…

  15. Utah's New Mathematics Core

    Science.gov (United States)

    Utah State Office of Education, 2011

    2011-01-01

    Utah has adopted more rigorous mathematics standards known as the Utah Mathematics Core Standards. They are the foundation of the mathematics curriculum for the State of Utah. The standards include the skills and understanding students need to succeed in college and careers. They include rigorous content and application of knowledge and reflect…

  16. Some Core Contested Concepts

    Science.gov (United States)

    Chomsky, Noam

    2015-01-01

    Core concepts of language are highly contested. In some cases this is legitimate: real empirical and conceptual issues arise. In other cases, it seems that controversies are based on misunderstanding. A number of crucial cases are reviewed, and an approach to language is outlined that appears to have strong conceptual and empirical motivation, and…

  17. Reactor core structure

    International Nuclear Information System (INIS)

    Higashinakagawa, Emiko; Sato, Kanemitsu.

    1992-01-01

    Taking notice on the fact that Fe based alloys and Ni based alloys are corrosion resistant in a special atmosphere of a nuclear reactor, Fe or Ni based alloys are applied to reactor core structural components such as fuel cladding tubes, fuel channels, spacers, etc. On the other hand, the neutron absorption cross section of zirconium is 0.18 barn while that of iron is 2.52 barn and that of nickel is 4.6 barn, which amounts to 14 to 25 times compared with that of zirconium. Accordingly, if the reactor core structural components are constituted by the Fe or Ni based alloys, neutron economy is lowered. Since it is desirable that neutrons contribute to uranium fission with least absorption to the reactor core structural components, the reactor core structural components are constituted with the Fe or Ni based alloys of good corrosion resistance only at a portion in contact with reactor water, that is, at a surface portion, while the main body is constituted with zircalloy in the present invention. Accordingly, corrosion resistnace can be kept while keeping small neutron absorption cross section. (T.M.)

  18. Investigation of EAS cores

    Directory of Open Access Journals (Sweden)

    Shaulov S.B.

    2017-01-01

    Full Text Available The development of nuclear-electromagnetic cascade models in air in the late forties have shown informational content of the study of cores of extensive air showers (EAS. These investigations were the main goal in different experiments which were carried out over many years by a variety of methods. Outcomes of such investigations obtained in the HADRON experiment using an X-ray emulsion chamber (XREC as a core detector are considered. The Ne spectrum of EAS associated with γ-ray families, spectra of γ-rays (hadrons in EAS cores and the Ne dependence of the muon number, ⟨Nμ⟩, in EAS with γ-ray families are obtained for the first time at energies of 1015–1017 eV with this method. A number of new effects were observed, namely, an abnormal scaling violation in hadron spectra which are fundamentally different from model predictions, an excess of muon number in EAS associated with γ-ray families, and the penetrating component in EAS cores. It is supposed that the abnormal behavior of γ-ray spectra and Ne dependence of the muon number are explained by the emergence of a penetrating component in the 1st PCR spectrum ‘knee’ range. Nuclear and astrophysical explanations of the origin of the penetrating component are discussed. The necessity of considering the contribution of a single close cosmic-ray source to explain the PCR spectrum in the knee range is noted.

  19. Plutonium cores of zenith

    Energy Technology Data Exchange (ETDEWEB)

    Barclay, F R; Cameron, I R; Drageset, A; Freemantle, R G; Wilson, D J

    1965-03-15

    The report describes a series of experiments carried out with plutonium fuel in the heated zero power reactor ZENITH, with the aim of testing current theoretical methods, with particular reference to excess reactivity, temperature coefficients, differential spectrum and reaction rate distributions. Two cores of widely different fissile/moderator atom ratios were loaded in order to test the theory under significantly varied spectrum conditions.

  20. Core damage risk indicators

    International Nuclear Information System (INIS)

    Szikszai, T.

    1994-01-01

    The purpose of this document is to show a method for the fast recalculation of the PSA. To avoid the information loose, it is necessary to simplify the PSA models, or at least reorganize them. The method, introduced in this document, require that preparation, so we try to show, how to do that. This document is an introduction. This is the starting point of the work related to the development of the risk indicators. In the future, with the application of this method, we are going to show an everyday use of the PSA results to produce the indicators of the core damage risk. There are two different indicators of the plant safety performance, related to the core damage risk. The first is the core damage frequency indicator (CDFI), and the second is the core damage probability indicator (CDPI). Of course, we cannot describe all of the possible ways to use these indicators, rather we will try to introduce the requirements to establish such an indicator system and the calculation process

  1. Core calculations of JMTR

    Energy Technology Data Exchange (ETDEWEB)

    Nagao, Yoshiharu [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment

    1998-03-01

    In material testing reactors like the JMTR (Japan Material Testing Reactor) of 50 MW in Japan Atomic Energy Research Institute, the neutron flux and neutron energy spectra of irradiated samples show complex distributions. It is necessary to assess the neutron flux and neutron energy spectra of an irradiation field by carrying out the nuclear calculation of the core for every operation cycle. In order to advance core calculation, in the JMTR, the application of MCNP to the assessment of core reactivity and neutron flux and spectra has been investigated. In this study, in order to reduce the time for calculation and variance, the comparison of the results of the calculations by the use of K code and fixed source and the use of Weight Window were investigated. As to the calculation method, the modeling of the total JMTR core, the conditions for calculation and the adopted variance reduction technique are explained. The results of calculation are shown. Significant difference was not observed in the results of neutron flux calculations according to the difference of the modeling of fuel region in the calculations by K code and fixed source. The method of assessing the results of neutron flux calculation is described. (K.I.)

  2. Emergency core cooling system

    International Nuclear Information System (INIS)

    Kato, Ken.

    1989-01-01

    In PWR type reactors, a cooling water spray portion of emergency core cooling pipelines incorporated into pipelines on high temperature side is protruded to the inside of an upper plenum. Upon rupture of primary pipelines, pressure in a pressure vessel is abruptly reduced to generate a great amount of steams in the reactor core, which are discharged at a high flow rate into the primary pipelines on high temperature side. However, since the inside of the upper plenum has a larger area and the steam flow is slow, as compared with that of the pipelines on the high temperature side, ECCS water can surely be supplied into the reactor core to promote the re-flooding of the reactor core and effectively cool the reactor. Since the nuclear reactor can effectively be cooled to enable the promotion of pressure reduction and effective supply of coolants during the period of pressure reduction upon LOCA, the capacity of the pressure accumulation vessel can be decreased. Further, the re-flooding time for the reactor is shortened to provide an effect contributing to the improvement of the safety and the reduction of the cost. (N.H.)

  3. Inflation targeting and core inflation

    OpenAIRE

    Julie Smith

    2005-01-01

    This paper examines the interaction of core inflation and inflation targeting as a monetary policy regime. Interest in core inflation has grown because of inflation targeting. Core inflation is defined in numerous ways giving rise to many potential measures; this paper defines core inflation as the best forecaster of inflation. A cross-country study finds before the start of inflation targeting, but not after, core inflation differs between non-inflation targeters and inflation targeters. Thr...

  4. A protein that binds to the P1 origin core and the oriC 13mer region in a methylation-specific fashion is the product of the host seqA gene.

    Science.gov (United States)

    Brendler, T; Abeles, A; Austin, S

    1995-08-15

    The P1 plasmid replication origin P1oriR is controlled by methylation of four GATC adenine methylation sites within heptamer repeats. A comparable (13mer) region is present in the host origin, oriC. The two origins show comparable responses to methylation; negative control by recognition of hemimethylated DNA (sequestration) and a positive requirement for methylation for efficient function. We have isolated a host protein that recognizes the P1 origin region only when it is isolated from a strain proficient for adenine methylation. The substantially purified 22 kDa protein also binds to the 13mer region of oriC in a methylation-specific fashion. It proved to be the product of the seqA gene that acts in the negative control of oriC by sequestration. We conclude that the role of the SeqA protein in sequestration is to recognize the methylation state of P1oriR and oriC by direct DNA binding. Using synthetic substrates we show that SeqA binds exclusively to the hemimethylated forms of these origins forms that are the immediate products of replication in a methylation-proficient strain. We also show that the protein can recognize sequences with multiple GATC sites, irrespective of the surrounding sequence. The basis for origin specificity is primarily the persistence of hemimethylated forms that are over-represented in the natural. DNA preparations relative to controls.

  5. CORE annual report 2006; CORE Jahresbericht 2006

    Energy Technology Data Exchange (ETDEWEB)

    Gut, A

    2007-04-15

    This annual report for the Swiss Federal Office of Energy (SFOE) summarises the activities of the Swiss Federal Commission on Energy Research CORE in 2006. The six main areas of work during the period 2004 - 2007 are examined, including a review of the SFOE's energy research programme, a road-map for the way towards the realisation of a 2000-watt society, the formulation of an energy research concept for 2008 - 2011, international co-operation, the dissemination of information and the assessment of existing and new instruments. International activities and Switzerland's involvement in energy research within the framework of the International Energy Agency IEA are discussed. New and existing projects are listed and the work done at the Competence Centre for Energy and Mobility noted. The Swiss Technology Award 2007 is presented. Information supplied to interested bodies to help improve knowledge on research work being done and to help make discussions on future energy supply more objective is discussed.

  6. New sensitive and specific assay for human immunodeficiency virus antibodies using labeled recombinant fusion protein and time-resolved fluoroimmunoassay.

    OpenAIRE

    Siitari, H; Turunen, P; Schrimsher, J; Nunn, M

    1990-01-01

    A new, rapid method for the detection of human immunodeficiency virus type 1 (HIV-1) antibody by time-resolved fluoroimmunoassay (TR-FIA) was developed. In this assay format, microtitration strips were coated with a recombinant fusion protein, and the same protein was labeled with europium and added into the wells simultaneously with the test specimens. The recombinant fusion protein contained the HIV-1 p24 gag protein sequence that carried an insertion, near the carboxyl terminus, of a 23-am...

  7. Prediction of Protein-Protein Interactions Related to Protein Complexes Based on Protein Interaction Networks

    Directory of Open Access Journals (Sweden)

    Peng Liu

    2015-01-01

    Full Text Available A method for predicting protein-protein interactions based on detected protein complexes is proposed to repair deficient interactions derived from high-throughput biological experiments. Protein complexes are pruned and decomposed into small parts based on the adaptive k-cores method to predict protein-protein interactions associated with the complexes. The proposed method is adaptive to protein complexes with different structure, number, and size of nodes in a protein-protein interaction network. Based on different complex sets detected by various algorithms, we can obtain different prediction sets of protein-protein interactions. The reliability of the predicted interaction sets is proved by using estimations with statistical tests and direct confirmation of the biological data. In comparison with the approaches which predict the interactions based on the cliques, the overlap of the predictions is small. Similarly, the overlaps among the predicted sets of interactions derived from various complex sets are also small. Thus, every predicted set of interactions may complement and improve the quality of the original network data. Meanwhile, the predictions from the proposed method replenish protein-protein interactions associated with protein complexes using only the network topology.

  8. Ice cores and palaeoclimate

    International Nuclear Information System (INIS)

    Krogh Andersen, K.; Ditlevsen, P.; Steffensen, J.P.

    2001-01-01

    Ice cores from Greenland give testimony of a highly variable climate during the last glacial period. Dramatic climate warmings of 15 to 25 deg. C for the annual average temperature in less than a human lifetime have been documented. Several questions arise: Why is the Holocene so stable? Is climatic instability only a property of glacial periods? What is the mechanism behind the sudden climate changes? Are the increased temperatures in the past century man-made? And what happens in the future? The ice core community tries to attack some of these problems. The NGRIP ice core currently being drilled is analysed in very high detail, allowing for a very precise dating of climate events. It will be possible to study some of the fast changes on a year by year basis and from this we expect to find clues to the sequence of events during rapid changes. New techniques are hoped to allow for detection of annual layers as far back as 100,000 years and thus a much improved time scale over past climate changes. It is also hoped to find ice from the Eemian period. If the Eemian layers confirm the GRIP sequence, the Eemian was actually climatically unstable just as the glacial period. This would mean that the stability of the Holocene is unique. It would also mean, that if human made global warming indeed occurs, we could jeopardize the Holocene stability and create an unstable 'Eemian situation' which ultimately could start an ice age. Currenlty mankind is changing the composition of the atmosphere. Ice cores document significant increases in greenhouse gases, and due to increased emissions of sulfuric and nitric acid from fossil fuel burning, combustion engines and agriculture, modern Greenland snow is 3 - 5 times more acidic than pre-industrial snow (Mayewski et al., 1986). However, the magnitude and abruptness of the temperature changes of the past century do not exceed the magnitude of natural variability. It is from the ice core perspective thus not possible to attribute the

  9. Is a malleable protein necessarily highly dynamic?

    DEFF Research Database (Denmark)

    Kjærgaard, Magnus; Poulsen, Flemming Martin; Teilum, Kaare

    2012-01-01

    core of NCBD in the ligand-free state and in a well-folded complex with the ligand activator for thyroid hormone and retinoid receptors using multiple NMR methods including methyl chemical shifts, coupling constants, and methyl order parameters. From all NMR measures, the aliphatic side chains...... in the hydrophobic core are slightly more dynamic in the free protein than in the complex, but have mobility comparable to the hydrophobic cores of average folded proteins. Urea titration monitored by NMR reveals that all parts of the protein, including the side-chain packing in the hydrophobic core, denatures...

  10. Emergency core cooling device

    International Nuclear Information System (INIS)

    Suzaki, Kiyoshi; Inoue, Akihiro.

    1979-01-01

    Purpose: To improve core cooling effect by making the operation region for a plurality of water injection pumps more broader. Constitution: An emergency reactor core cooling device actuated upon failure of recycling pipe ways is adapted to be fed with cooling water through a thermal sleeve by way of a plurality of water injection pump from pool water in a condensate storage tank and a pressure suppression chamber as water feed source. Exhaust pipes and suction pipes of each of the pumps are connected by way of switching valves and the valves are switched so that the pumps are set to a series operation if the pressure in the pressure vessel is high and the pumps are set to a parallel operation if the pressure in the pressure vessel is low. (Furukawa, Y.)

  11. Birefringent hollow core fibers

    DEFF Research Database (Denmark)

    Roberts, John

    2007-01-01

    Hollow core photonic crystal fiber (HC-PCF), fabricated according to a nominally non-birefringent design, shows a degree of un-controlled birefringence or polarization mode dispersion far in excess of conventional non polarization maintaining fibers. This can degrade the output pulse in many...... applications, and places emphasis on the development of polarization maintaining (PM) HC-PCF. The polarization cross-coupling characteristics of PM HC-PCF are very different from those of conventional PM fibers. The former fibers have the advantage of suffering far less from stress-field fluctuations...... and an increased overlap between the polarization modes at the glass interfaces. The interplay between these effects leads to a wavelength for optimum polarization maintenance, lambda(PM), which is detuned from the wavelength of highest birefringence. By a suitable fiber design involving antiresonance of the core...

  12. Plasma core reactor applications

    International Nuclear Information System (INIS)

    Latham, T.S.; Rodgers, R.J.

    1976-01-01

    Analytical and experimental investigations are being conducted to demonstrate the feasibility of fissioning uranium plasma core reactors and to characterize space and terrestrial applications for such reactors. Uranium hexafluoride (UF 6 ) fuel is injected into core cavities and confined away from the surface by argon buffer gas injected tangentially from the peripheral walls. Power, in the form of thermal radiation emitted from the high-temperature nuclear fuel, is transmitted through fused-silica transparent walls to working fluids which flow in axial channels embedded in segments of the cavity walls. Radiant heat transfer calculations were performed for a six-cavity reactor configuration; each cavity is approximately 1 m in diameter by 4.35 m in length. Axial working fluid channels are located along a fraction of each cavity peripheral wall

  13. Reactor core cooling device

    International Nuclear Information System (INIS)

    Kobayashi, Masahiro.

    1986-01-01

    Purpose: To safely and effectively cool down the reactor core after it has been shut down but is still hot due to after-heat. Constitution: Since the coolant extraction nozzle is situated at a location higher than the coolant injection nozzle, the coolant sprayed from the nozzle, is free from sucking immediately from the extraction nozzle and is therefore used effectively to cool the reactor core. As all the portions from the top to the bottom of the reactor are cooled simultaneously, the efficiency of the reactor cooling process is increased. Since the coolant extraction nozzle can be installed at a point considerably higher than the coolant injection nozzle, the distance from the coolant surface to the point of the coolant extraction nozzle can be made large, preventing cavitation near the coolant extraction nozzle. Therefore, without increasing the capacity of the heat exchanger, the reactor can be cooled down after a shutdown safely and efficiently. (Kawakami, Y.)

  14. Some core contested concepts.

    Science.gov (United States)

    Chomsky, Noam

    2015-02-01

    Core concepts of language are highly contested. In some cases this is legitimate: real empirical and conceptual issues arise. In other cases, it seems that controversies are based on misunderstanding. A number of crucial cases are reviewed, and an approach to language is outlined that appears to have strong conceptual and empirical motivation, and to lead to conclusions about a number of significant issues that differ from some conventional beliefs.

  15. Schumpeter's core works revisited

    DEFF Research Database (Denmark)

    Andersen, Esben Sloth

    2012-01-01

    This paper organises Schumpeter’s core books in three groups: the programmatic duology,the evolutionaryeconomic duology,and the socioeconomic synthesis. By analysing these groups and their interconnections from the viewpoint of modern evolutionaryeconomics,the paper summarises resolved problems a...... and points at remaining challenges. Its analyses are based on distinctions between microevolution and macroevolution, between economic evolution and socioeconomic coevolution, and between Schumpeter’s three major evolutionary models (called Mark I, Mark II and Mark III)....

  16. CORAL: aligning conserved core regions across domain families.

    Science.gov (United States)

    Fong, Jessica H; Marchler-Bauer, Aron

    2009-08-01

    Homologous protein families share highly conserved sequence and structure regions that are frequent targets for comparative analysis of related proteins and families. Many protein families, such as the curated domain families in the Conserved Domain Database (CDD), exhibit similar structural cores. To improve accuracy in aligning such protein families, we propose a profile-profile method CORAL that aligns individual core regions as gap-free units. CORAL computes optimal local alignment of two profiles with heuristics to preserve continuity within core regions. We benchmarked its performance on curated domains in CDD, which have pre-defined core regions, against COMPASS, HHalign and PSI-BLAST, using structure superpositions and comprehensive curator-optimized alignments as standards of truth. CORAL improves alignment accuracy on core regions over general profile methods, returning a balanced score of 0.57 for over 80% of all domain families in CDD, compared with the highest balanced score of 0.45 from other methods. Further, CORAL provides E-values to aid in detecting homologous protein families and, by respecting block boundaries, produces alignments with improved 'readability' that facilitate manual refinement. CORAL will be included in future versions of the NCBI Cn3D/CDTree software, which can be downloaded at http://www.ncbi.nlm.nih.gov/Structure/cdtree/cdtree.shtml. Supplementary data are available at Bioinformatics online.

  17. BWR type reactor core

    International Nuclear Information System (INIS)

    Tatemichi, Shin-ichiro.

    1981-01-01

    Purpose: To eliminate the variation in the power distribution of a BWR type reactor core in the axial direction even if the flow rate is increased or decreased by providing a difference in the void coefficient between the upper part and the lower parts of the reactor core, and increasing the void coefficient at the lower part of the reactor core. Constitution: The void coefficient of the lower region from the center to the lower part along the axial direction of a nuclear fuel assembly is increased to decrease the dependence on the flow rate of the axial power distribution of the nuclear fuel assembly. That is, a water/fuel ratio is varied, the water in non-boiled region is increased or the neutron spectrum is varied so as to vary the void coefficient. In order to exemplify it, the rate of the internal pellets of the fuel rod of the nuclear fuel assembly or the shape of the channel box is varied. Accordingly, the power does not considerably vary even if the flow rate is altered since the power is varied in the power operation. (Yoshihara, H.)

  18. Emergency core cooling system

    International Nuclear Information System (INIS)

    Ando, Masaki.

    1987-01-01

    Purpose: To actuate an automatic pressure down system (ADS) and a low pressure emergency core cooling system (ECCS) upon water level reduction of a nuclear reactor other than loss of coolant accidents (LOCA). Constitution: ADS in a BWR type reactor is disposed for reducing the pressure in a reactor container thereby enabling coolant injection from a low pressure ECCS upon LOCA. That is, ADS has been actuated by AND signal for a reactor water level low signal and a dry well pressure high signal. In the present invention, ADS can be actuated further also by AND signal of the reactor water level low signal, the high pressure ECCS and not-operation signal of reactor isolation cooling system. In such an emergency core cooling system thus constituted, ADS operates in the same manner as usual upon LOCA and, further, ADS is operated also upon loss of feedwater accident in the reactor pressure vessel in the case where there is a necessity for actuating the low pressure ECCS, although other high pressure ECCS and reactor isolation cooling system are not operated. Accordingly, it is possible to improve the reliability upon reactor core accident and mitigate the operator burden. (Horiuchi, T.)

  19. Gap junctions and connexin-interacting proteins

    NARCIS (Netherlands)

    Giepmans, Ben N G

    2004-01-01

    Gap junctions form channels between adjacent cells. The core proteins of these channels are the connexins. Regulation of gap junction communication (GJC) can be modulated by connexin-associating proteins, such as regulatory protein phosphatases and protein kinases, of which c-Src is the

  20. Conformation of glycomimetics in the free and protein-bound state: structural and binding features of the C-glycosyl analogue of the core trisaccharide alpha-D-Man-(1 --> 3)-[alpha-D-Man-(1 --> 6)]-D-Man.

    Science.gov (United States)

    Mikkelsen, Lise Munch; Hernáiz, María José; Martín-Pastor, M; Skrydstrup, Troels; Jiménez-Barbero, Jesús

    2002-12-18

    The conformational properties of the C-glycosyl analogue of the core trisaccharide alpha-D-Man-(1 --> 3)-[alpha-D-Man-(1 --> 6)]-D-Man in solution have been carefully analyzed by a combination of NMR spectroscopy and time-averaged restrained molecular dynamics. It has been found that both the alpha-1,3- and the alpha-1,6-glycosidic linkages show a major conformational averaging. Unusual Phi ca. 60 degrees orientations for both Phi torsion angles are found. Moreover, a major conformational distinction between the natural compound and the glycomimetic affects to the behavior of the omega(16) torsion angle around the alpha-1 --> 6-linkage. Despite this increased flexibility, the C-glycosyl analogue is recognized by three mannose binding lectins, as shown by NMR (line broadening, TR-NOE, and STD) and surface plasmon resonance (SPR) methods. Moreover, a process of conformational selection takes place, so that these lectins probably bind the glycomimetic similarly to the way they recognize the natural analogue. Depending upon the architecture and extension of the binding site of the lectin, loss or gain of binding affinity with respect to the natural analogue is found.

  1. Molten salt reactors: reactor cores

    International Nuclear Information System (INIS)

    1983-01-01

    In this critical analysis of the MSBR I project are examined the problems concerning the reactor core. Advantages of breeding depend essentially upon solutions to technological problems like continuous reprocessing or graphite behavior under neutron irradiation. Graphite deformation, moderator unloading, control rods and core instrumentation require more studies. Neutronics of the core, influence of core geometry and salt composition, fuel evolution, and thermohydraulics are reviewed [fr

  2. WNP-2 core model upgrade

    International Nuclear Information System (INIS)

    Golightly, C.E.; Ravindranath, T.K.; Belblidia, L.A.; O'Farrell, D.; Andersen, P.S.

    2006-01-01

    The paper describes the core model upgrade of the WNP-2 training simulator and the reasons for the upgrade. The core model as well as the interface with the rest of the simulator are briefly described . The paper also describes the procedure that will be used by WNP-2 to update the simulator core data after future core reloads. Results from the fully integrated simulator are presented. (author)

  3. On-line core monitoring with CORE MASTER / PRESTO

    International Nuclear Information System (INIS)

    Lindahl, S.O.; Borresen, S.; Ovrum, S.

    1986-01-01

    Advanced calculational tools are instrumental in improving reactor plant capacity factors and fuel utilization. The computer code package CORE MASTER is an integrated system designed to achieve this objective. The system covers all main activities in the area of in-core fuel management for boiling water reactors; design, operation support, and on-line core monitoring. CORE MASTER operates on a common data base, which defines the reactor and documents the operating history of the core and of all fuel bundles ever used

  4. Hollow-Core Fiber Lamp

    Science.gov (United States)

    Yi, Lin (Inventor); Tjoelker, Robert L. (Inventor); Burt, Eric A. (Inventor); Huang, Shouhua (Inventor)

    2016-01-01

    Hollow-core capillary discharge lamps on the millimeter or sub-millimeter scale are provided. The hollow-core capillary discharge lamps achieve an increased light intensity ratio between 194 millimeters (useful) and 254 millimeters (useless) light than conventional lamps. The capillary discharge lamps may include a cone to increase light output. Hollow-core photonic crystal fiber (HCPCF) may also be used.

  5. Dual-core Itanium Processor

    CERN Multimedia

    2006-01-01

    Intel’s first dual-core Itanium processor, code-named "Montecito" is a major release of Intel's Itanium 2 Processor Family, which implements the Intel Itanium architecture on a dual-core processor with two cores per die (integrated circuit). Itanium 2 is much more powerful than its predecessor. It has lower power consumption and thermal dissipation.

  6. Maximum stellar iron core mass

    Indian Academy of Sciences (India)

    60, No. 3. — journal of. March 2003 physics pp. 415–422. Maximum stellar iron core mass. F W GIACOBBE. Chicago Research Center/American Air Liquide ... iron core compression due to the weight of non-ferrous matter overlying the iron cores within large .... thermal equilibrium velocities will tend to be non-relativistic.

  7. Core TuLiP

    NARCIS (Netherlands)

    Czenko, M.R.; Etalle, Sandro

    2007-01-01

    We propose CoreTuLiP - the core of a trust management language based on Logic Programming. CoreTuLiP is based on a subset of moded logic programming, but enjoys the features of TM languages such as RT; in particular clauses are issued by different authorities and stored in a distributed manner. We

  8. Automated Core Design

    International Nuclear Information System (INIS)

    Kobayashi, Yoko; Aiyoshi, Eitaro

    2005-01-01

    Multistate searching methods are a subfield of distributed artificial intelligence that aims to provide both principles for construction of complex systems involving multiple states and mechanisms for coordination of independent agents' actions. This paper proposes a multistate searching algorithm with reinforcement learning for the automatic core design of a boiling water reactor. The characteristics of this algorithm are that the coupling structure and the coupling operation suitable for the assigned problem are assumed and an optimal solution is obtained by mutual interference in multistate transitions using multiagents. Calculations in an actual plant confirmed that the proposed algorithm increased the convergence ability of the optimization process

  9. Ice Sheets & Ice Cores

    DEFF Research Database (Denmark)

    Mikkelsen, Troels Bøgeholm

    Since the discovery of the Ice Ages it has been evident that Earth’s climate is liable to undergo dramatic changes. The previous climatic period known as the Last Glacial saw large oscillations in the extent of ice sheets covering the Northern hemisphere. Understanding these oscillations known....... The first part concerns time series analysis of ice core data obtained from the Greenland Ice Sheet. We analyze parts of the time series where DO-events occur using the so-called transfer operator and compare the results with time series from a simple model capable of switching by either undergoing...

  10. Nuclear reactor core assembly

    International Nuclear Information System (INIS)

    Baxi, C.B.

    1978-01-01

    The object of the present invention is to provide a fast reactor core assembly design for use with a fluid coolant such as liquid sodium or carbon monoxide incorporating a method of increasing the percentage of coolant flow though the blanket elements relative to the total coolant flow through the blanket and fuel elements during shutdown conditions without using moving parts. It is claimed that deterioration due to reactor radiation or temperature conditions is avoided and ready modification or replacement is possible. (U.K.)

  11. Reload core safety verification

    International Nuclear Information System (INIS)

    Svetlik, M.; Minarcin, M.

    2003-01-01

    This paper presents a brief look at the process of reload core safety evaluation and verification in Slovak Republic. It gives an overview of experimental verification of selected nuclear parameters in the course of physics testing during reactor start-up. The comparison of IAEA recommendations and testing procedures at Slovak and European nuclear power plants of similar design is included. An introduction of two level criteria for evaluation of tests represents an effort to formulate the relation between safety evaluation and measured values (Authors)

  12. RB reactor benchmark cores

    International Nuclear Information System (INIS)

    Pesic, M.

    1998-01-01

    A selected set of the RB reactor benchmark cores is presented in this paper. The first results of validation of the well-known Monte Carlo MCNP TM code and adjoining neutron cross section libraries are given. They confirm the idea for the proposal of the new U-D 2 O criticality benchmark system and support the intention to include this system in the next edition of the recent OECD/NEA Project: International Handbook of Evaluated Criticality Safety Experiment, in near future. (author)

  13. How cores grow by pebble accretion. I. Direct core growth

    Science.gov (United States)

    Brouwers, M. G.; Vazan, A.; Ormel, C. W.

    2018-03-01

    Context. Planet formation by pebble accretion is an alternative to planetesimal-driven core accretion. In this scenario, planets grow by the accretion of cm- to m-sized pebbles instead of km-sized planetesimals. One of the main differences with planetesimal-driven core accretion is the increased thermal ablation experienced by pebbles. This can provide early enrichment to the planet's envelope, which influences its subsequent evolution and changes the process of core growth. Aims: We aim to predict core masses and envelope compositions of planets that form by pebble accretion and compare mass deposition of pebbles to planetesimals. Specifically, we calculate the core mass where pebbles completely evaporate and are absorbed before reaching the core, which signifies the end of direct core growth. Methods: We model the early growth of a protoplanet by calculating the structure of its envelope, taking into account the fate of impacting pebbles or planetesimals. The region where high-Z material can exist in vapor form is determined by the temperature-dependent vapor pressure. We include enrichment effects by locally modifying the mean molecular weight of the envelope. Results: In the pebble case, three phases of core growth can be identified. In the first phase (Mcore mixes outwards, slowing core growth. In the third phase (Mcore > 0.5M⊕), the high-Z inner region expands outwards, absorbing an increasing fraction of the ablated material as vapor. Rainout ends before the core mass reaches 0.6 M⊕, terminating direct core growth. In the case of icy H2O pebbles, this happens before 0.1 M⊕. Conclusions: Our results indicate that pebble accretion can directly form rocky cores up to only 0.6 M⊕, and is unable to form similarly sized icy cores. Subsequent core growth can proceed indirectly when the planet cools, provided it is able to retain its high-Z material.

  14. [The true story and advantages of the famous Hepatitis B virus core particles: Outlook 2016].

    Science.gov (United States)

    Pumpens, P; Grens, E

    2016-01-01

    This review article is a continuation of the paper "Hepatitis B core particles as a universal display model: a structure-function basis for development" written by Pumpens P. and Grens E., ordered by Professor Lev Kisselev and published in FEBS Letters, 1999, 442, 1-6. The past 17 years have strengthened the paper's finding that the human hepatitis B virus core protein, along with other Hepadnaviridae family member core proteins, is a mysterious, multifunctional protein. The core gene of the Hepadnaviridae genome encodes five partially collinear proteins. The most important of these is the HBV core protein p21, or HBc. It can self-assemble by forming viral HBc particles, but also plays a crucial role in the regulation of viral replication. Since 1986, the HBc protein has been one of the first and the most successful tools of the virus-like particle (VLP) technology. Later, the woodchuck hepatitis virus core protein (WHc) was also used as a VLP carrier. The Hepadnaviridae core proteins remain favourite VLP candidates for the knowledge-based design of future vaccines, gene therapy vectors, specifically targeted nanocontainers, and other modern nanotechnological tools for prospective medical use.

  15. TMI-2 core examination plan

    International Nuclear Information System (INIS)

    Owen, D.E.; MacDonald, P.E.; Hobbins, R.R.; Ploggr, S.A.

    1982-01-01

    The Three Mile Island (TMI-2) core examination is divided into four stages: (1) before removing the head; (2) before removing the plenum; (3) during defueling; and (4) offsite examinations. Core examinations recommended during the first three stages are primarily devoted to documenting the post-accident condition of the core. The detailed analysis of core damage structures will be performed during offsite examinations at government and commercial hot cell facilities. The primary objectives of these examinations are to enhance the understanding of the degraded core accident sequence, to develop the technical bases for reactor regulations, and to improve LWR design and operation

  16. Monitoring an electric cable core

    International Nuclear Information System (INIS)

    Bhattacharya, S.; Marris, A.

    1984-01-01

    A method of, and apparatus for, continuously monitoring an advancing core having a continuous covering comprises directing X-ray radiation laterally towards the advancing covered core; continuously forming an X-ray image pattern of the advancing covered core and translating the image pattern into a visible image pattern; continuously transforming the visible pattern into a digital bit pattern; and processing the digital bit pattern using a microprocessor with interfacing electronics to provide an image profile of the advancing covered core and/or to provide analogue and/or digital signals indicative of the overall diameter and eccentricity of the covered core and of the thickness of the covering. (author)

  17. Winning Cores in Parity Games

    DEFF Research Database (Denmark)

    Vester, Steen

    2016-01-01

    We introduce the novel notion of winning cores in parity games and develop a deterministic polynomial-time under-approximation algorithm for solving parity games based on winning core approximation. Underlying this algorithm are a number properties about winning cores which are interesting...... in their own right. In particular, we show that the winning core and the winning region for a player in a parity game are equivalently empty. Moreover, the winning core contains all fatal attractors but is not necessarily a dominion itself. Experimental results are very positive both with respect to quality...

  18. Initial charge reactor core

    International Nuclear Information System (INIS)

    Kiyono, Takeshi

    1984-01-01

    Purpose: To effectivity burn fuels and improve the economical performance in an inital charge reactor core of BWR type reactors or the likes. Constitution: In a reactor core constituted with a plurality of fuel assemblies which are to be partially replaced upon fuel replacement, the density of the fissionable materials and the moderator - fuel ratio of a fuel assembly is set corresponding to the period till that fuel assembly is replaced, in which the density of the nuclear fissionable materials is lowered and the moderator - fuel ratio is increased for the fuel assembly with a shorter period from the fueling to the fuel exchange and, while on the other hand, the density of the fissionable materials is increased and the moderator - fuel ratio is decreased for the fuel assembly with a longer period from the fueling to the replacement. Accordingly, since the moderator - fuel ratio is increased for the fuel assembly to be replaced in a shorter period, the neutrons moderating effect is increased to increase the reactivity. (Horiuchi, T.)

  19. Statistical core design

    International Nuclear Information System (INIS)

    Oelkers, E.; Heller, A.S.; Farnsworth, D.A.; Kearfott, K.J.

    1978-01-01

    The report describes the statistical analysis of DNBR thermal-hydraulic margin of a 3800 MWt, 205-FA core under design overpower conditions. The analysis used LYNX-generated data at predetermined values of the input variables whose uncertainties were to be statistically combined. LYNX data were used to construct an efficient response surface model in the region of interest; the statistical analysis was accomplished through the evaluation of core reliability; utilizing propagation of the uncertainty distributions of the inputs. The response surface model was implemented in both the analytical error propagation and Monte Carlo Techniques. The basic structural units relating to the acceptance criteria are fuel pins. Therefore, the statistical population of pins with minimum DNBR values smaller than specified values is determined. The specified values are designated relative to the most probable and maximum design DNBR values on the power limiting pin used in present design analysis, so that gains over the present design criteria could be assessed for specified probabilistic acceptance criteria. The results are equivalent to gains ranging from 1.2 to 4.8 percent of rated power dependent on the acceptance criterion. The corresponding acceptance criteria range from 95 percent confidence that no pin will be in DNB to 99.9 percent of the pins, which are expected to avoid DNB

  20. Nuclear reactor core

    International Nuclear Information System (INIS)

    Koyama, Jun-ichi; Aoyama, Motoo; Ishibashi, Yoko; Mochida, Takaaki; Haikawa, Katsumasa; Yamanaka, Akihiro.

    1995-01-01

    A reactor core is radially divided into an inner region, an outer region and an outermost region. As a fuel, three kinds of fuels, namely, a high enrichment degree fuel at 3.4%, a middle enrichment degree fuel at 2.3% and a low enrichment degree at 1.1% of a fuel average enrichment degree of fission product are used. Each of the fuels is bisected to upper and lower portions at an axial center thereof. The difference of average enrichment degrees between upper and lower portions is 0.1% for the high enrichment degree fuel, 0.3% for the middle enrichment degree fuel and 0.2% for the low enrichment degree fuel. In addition, the composition of fuels in each of radial regions comprises 100% of the low enrichment degree fuels in the outermost region, 91% of the higher enrichment degree fuels and 9% of the middle enrichment degree fuels in the outer region, and 34% of the high enrichment degree fuels and 30% of the middle enrichment degree fuels in the inner region. With such a constitution, fuel economy can be improved while maintaining the thermal margin in an initially loaded reactor core of a BWR type reactor. (I.N.)

  1. Models of the earth's core

    Science.gov (United States)

    Stevenson, D. J.

    1981-01-01

    Combined inferences from seismology, high-pressure experiment and theory, geomagnetism, fluid dynamics, and current views of terrestrial planetary evolution lead to models of the earth's core with five basic properties. These are that core formation was contemporaneous with earth accretion; the core is not in chemical equilibrium with the mantle; the outer core is a fluid iron alloy containing significant quantities of lighter elements and is probably almost adiabatic and compositionally uniform; the more iron-rich inner solid core is a consequence of partial freezing of the outer core, and the energy release from this process sustains the earth's magnetic field; and the thermodynamic properties of the core are well constrained by the application of liquid-state theory to seismic and labroatory data.

  2. Oligomeric protein structure networks: insights into protein-protein interactions

    Directory of Open Access Journals (Sweden)

    Brinda KV

    2005-12-01

    Full Text Available Abstract Background Protein-protein association is essential for a variety of cellular processes and hence a large number of investigations are being carried out to understand the principles of protein-protein interactions. In this study, oligomeric protein structures are viewed from a network perspective to obtain new insights into protein association. Structure graphs of proteins have been constructed from a non-redundant set of protein oligomer crystal structures by considering amino acid residues as nodes and the edges are based on the strength of the non-covalent interactions between the residues. The analysis of such networks has been carried out in terms of amino acid clusters and hubs (highly connected residues with special emphasis to protein interfaces. Results A variety of interactions such as hydrogen bond, salt bridges, aromatic and hydrophobic interactions, which occur at the interfaces are identified in a consolidated manner as amino acid clusters at the interface, from this study. Moreover, the characterization of the highly connected hub-forming residues at the interfaces and their comparison with the hubs from the non-interface regions and the non-hubs in the interface regions show that there is a predominance of charged interactions at the interfaces. Further, strong and weak interfaces are identified on the basis of the interaction strength between amino acid residues and the sizes of the interface clusters, which also show that many protein interfaces are stronger than their monomeric protein cores. The interface strengths evaluated based on the interface clusters and hubs also correlate well with experimentally determined dissociation constants for known complexes. Finally, the interface hubs identified using the present method correlate very well with experimentally determined hotspots in the interfaces of protein complexes obtained from the Alanine Scanning Energetics database (ASEdb. A few predictions of interface hot

  3. Waves in the core and mechanical core-mantle interactions

    DEFF Research Database (Denmark)

    Jault, D.; Finlay, Chris

    2015-01-01

    This Chapter focuses on time-dependent uid motions in the core interior, which can beconstrained by observations of the Earth's magnetic eld, on timescales which are shortcompared to the magnetic diusion time. This dynamics is strongly inuenced by the Earth's rapid rotation, which rigidies...... the motions in the direction parallel to the Earth'srotation axis. This property accounts for the signicance of the core-mantle topography.In addition, the stiening of the uid in the direction parallel to the rotation axis gives riseto a magnetic diusion layer attached to the core-mantle boundary, which would...... otherwisebe dispersed by Alfven waves. This Chapter complements the descriptions of large-scaleow in the core (8.04), of turbulence in the core (8.06) and of core-mantle interactions(8.12), which can all be found in this volume. We rely on basic magnetohydrodynamictheory, including the derivation...

  4. Core cooling systems

    International Nuclear Information System (INIS)

    Hoeppner, G.

    1980-01-01

    The reactor cooling system transports the heat liberated in the reactor core to the component - heat exchanger, steam generator or turbine - where the energy is removed. This basic task can be performed with a variety of coolants circulating in appropriately designed cooling systems. The choice of any one system is governed by principles of economics and natural policies, the design is determined by the laws of nuclear physics, thermal-hydraulics and by the requirement of reliability and public safety. PWR- and BWR- reactors today generate the bulk of nuclear energy. Their primary cooling systems are discussed under the following aspects: 1. General design, nuclear physics constraints, energy transfer, hydraulics, thermodynamics. 2. Design and performance under conditions of steady state and mild transients; control systems. 3. Design and performance under conditions of severe transients and loss of coolant accidents; safety systems. (orig./RW)

  5. The true 'core' splitting

    International Nuclear Information System (INIS)

    Hallerbach, J.

    1978-01-01

    Massive unemployment and the fear of a barred future put at present the unions and civil initiative to the apparent alternatives; securing work places or securing life and future. How the 'atomic fight' is fought and its result can have considerable consequences for our society. This volume presents a dialogue: Firstly the situation and environment must be understood giving rise to the controversial arguments. Reports, analyses and interviews are presented on this as basic structure for the future discussion. The quality and direction of the technical progress are dealt with in the core of the discussion. Is atomic technology acceptable. Who should decide and whom does it serve. What is progress going to look like anyway. (orig.) [de

  6. Emergency core cooling systems

    International Nuclear Information System (INIS)

    Kubokoya, Takashi; Okataku, Yasukuni.

    1984-01-01

    Purpose: To maintain the fuel soundness upon loss of primary coolant accidents in a pressure tube type nuclear reactor by injecting cooling heavy water at an early stage, to suppress the temperature of fuel cans at a lower level. Constitution: When a thermometer detects the temperature rise and a pressure gauge detects that the pressure for the primary coolants is reduced slightly from that in the normal operation upon loss of coolant accidents in the vicinity of the primary coolant circuit, heavy water is caused to flow in the heavy water feed pipeway by a controller. This enables to inject the heavy water into the reactor core in a short time upon loss of the primary coolant accidents to suppress the temperature rise in the fuel can thereby maintain the fuel soundness. (Moriyama, K.)

  7. The core and cosmopolitans

    DEFF Research Database (Denmark)

    Dahlander, Linus; Frederiksen, Lars

    2012-01-01

    Users often interact and help each other solve problems in communities, but few scholars have explored how these relationships provide opportunities to innovate. We analyze the extent to which people positioned within the core of a community as well as people that are cosmopolitans positioned...... across multiple external communities affect innovation. Using a multimethod approach, including a survey, a complete database of interactions in an online community, content coding of interactions and contributions, and 36 interviews, we specify the types of positions that have the strongest effect...... on innovation. Our study shows that dispositional explanations for user innovation should be complemented by a relational view that emphasizes how these communities differ from other organizations, the types of behaviors this enables, and the effects on innovation....

  8. Adult educators' core competences

    DEFF Research Database (Denmark)

    Wahlgren, Bjarne

    2016-01-01

    ” requirements, organising them into four thematic subcategories: (1) communicating subject knowledge; (2) taking students’ prior learning into account; (3) supporting a learning environment; and (4) the adult educator’s reflection on his or her own performance. At the end of his analysis of different competence......Abstract Which competences do professional adult educators need? This research note discusses the topic from a comparative perspective, finding that adult educators’ required competences are wide-ranging, heterogeneous and complex. They are subject to context in terms of national and cultural...... environment as well as the kind of adult education concerned (e.g. basic education, work-related education etc.). However, it seems that it is possible to identify certain competence requirements which transcend national, cultural and functional boundaries. This research note summarises these common or “core...

  9. CORE annual report 2006

    International Nuclear Information System (INIS)

    Gut, A.

    2007-04-01

    This annual report for the Swiss Federal Office of Energy (SFOE) summarises the activities of the Swiss Federal Commission on Energy Research CORE in 2006. The six main areas of work during the period 2004 - 2007 are examined, including a review of the SFOE's energy research programme, a road-map for the way towards the realisation of a 2000-watt society, the formulation of an energy research concept for 2008 - 2011, international co-operation, the dissemination of information and the assessment of existing and new instruments. International activities and Switzerland's involvement in energy research within the framework of the International Energy Agency IEA are discussed. New and existing projects are listed and the work done at the Competence Centre for Energy and Mobility noted. The Swiss Technology Award 2007 is presented. Information supplied to interested bodies to help improve knowledge on research work being done and to help make discussions on future energy supply more objective is discussed

  10. Nuclear reactor core

    Energy Technology Data Exchange (ETDEWEB)

    Prescott, R F

    1974-07-11

    The core of the fast neutron reactor consisting, among other components, of fuel elements enriched in plutonium is divided into modules. Each module contains a bundle of four or six elongated components (fuel elements and control rods). In the arrangement with four components, one is kept rigid while the other three are elastically yielding inclined towards the center and lean against the rigid component. In the modules with six pieces, each component is elastically yielding inclined towards a central cavity. In this way, they form a circular arc. A control rod may be placed in the cavity. In order to counteract a relative lateral movement, the outer surfaces of the components which have hexagonal cross-sections have interlocking bearing cushions. The bearing cushions consist of keyway-type ribs or grooves with the wedges or ribs gripping in the grooves of the neighbouring components. In addition, the ribs have oblique entering surfaces.

  11. IRIS core criticality calculations

    International Nuclear Information System (INIS)

    Jecmenica, R.; Trontl, K.; Pevec, D.; Grgic, D.

    2003-01-01

    Three-dimensional Monte Carlo computer code KENO-VI of CSAS26 sequence of SCALE-4.4 code system was applied for pin-by-pin calculations of the effective multiplication factor for the first cycle IRIS reactor core. The effective multiplication factors obtained by the above mentioned Monte Carlo calculations using 27-group ENDF/B-IV library and 238-group ENDF/B-V library have been compared with the effective multiplication factors achieved by HELIOS/NESTLE, CASMO/SIMULATE, and modified CORD-2 nodal calculations. The results of Monte Carlo calculations are found to be in good agreement with the results obtained by the nodal codes. The discrepancies in effective multiplication factor are typically within 1%. (author)

  12. Understanding core conductor fabrics

    International Nuclear Information System (INIS)

    Swenson, D E

    2011-01-01

    ESD Association standard test method ANSI/ESD STM2.1 - Garments (STM2.1), provides electrical resistance test procedures that are applicable for materials and garments that have surface conductive or surface dissipative properties. As has been reported in other papers over the past several years 1 fabrics are now used in many industries for electrostatic control purposes that do not have surface conductive properties and therefore cannot be evaluated using the procedures in STM2.1 2 . A study was conducted to compare surface conductive fabrics with samples of core conductor fibre based fabrics in order to determine differences and similarities with regards to various electrostatic properties. This work will be used to establish a new work item proposal within WG-2, Garments, in the ESD Association Standards Committee in the USA.

  13. Um mundo de cores

    Directory of Open Access Journals (Sweden)

    Elis Artz

    2016-08-01

    Full Text Available A pintura de Elis Artz é feita com muita alma e transborda alegria. A vitalidade de seu trabalho transparece nas cores fortes e nos traços simples e harmoniosos. Confira o trabalho da artista nesta edição da Revista Jangada. ELIS by ELIS Descobri meu talento artístisco e criativo há uns 25 anos. Nasci no Brasil e me mudei para os EUA 10 anos atrás por puro amor. Embora seja psicóloga de formação, o meu apreço pela pintura só cresceu e, com o passar dos anos, a paixão pelas tintas me direcionou a fazer cursos com artistas brasileiros renomados. Já morando nos EUA e com essa grande paixão adormecida, durante anos, decidi me entregar para as cores que sempre me trouxeram alegria e cor para os meus dias. Embora muitas de minhas pinturas tenham ido para minha família e amigos no Brasil, vendi inúmeras outras pelo país através de exposições em galerias de arte. Em 2014, fui uma das artistas em destaque no MTD ART nos Estados Unidos. Minha obra estava dentro de cada ônibus das cidades de Champaign e Urbana e exposta em destaque na Estação de Trem. Em maio de 2015, tive o prazer de ter outro trabalho meu nos outdoors da cidade, destacando a minha tela 'Frida' o ano inteiro e de expor em conjunto com alguns artistas locais no final de outubro. Desde então, tenho pintado cada vez mais e me interessado em divulgar o meu trabalho. E, como diria um amigo meu "Elis, você me mostrou que a vida não é só preto no branco". Ele estava certo.

  14. Growth outside the core.

    Science.gov (United States)

    Zook, Chris; Allen, James

    2003-12-01

    Growth in an adjacent market is tougher than it looks; three-quarters of the time, the effort fails. But companies can change those odds dramatically. Results from a five-year study of corporate growth conducted by Bain & Company reveal that adjacency expansion succeeds only when built around strong core businesses that have the potential to become market leaders. And the best place to look for adjacency opportunities is inside a company's strongest customers. The study also found that the most successful companies were able to consistently, profitably outgrow their rivals by developing a formula for pushing out the boundaries of their core businesses in predictable, repeatable ways. Companies use their repeatability formulas to expand into any number of adjacencies. Some companies make repeated geographic moves, as Vodafone has done in expanding from one geographic market to another over the past 13 years, building revenues from $1 billion in 1990 to $48 billion in 2003. Others apply a superior business model to new segments. Dell, for example, has repeatedly adapted its direct-to-customer model to new customer segments and new product categories. In other cases, companies develop hybrid approaches. Nike executed a series of different types of adjacency moves: it expanded into adjacent customer segments, introduced new products, developed new distribution channels, and then moved into adjacent geographic markets. The successful repeaters in the study had two common characteristics. First, they were extraordinarily disciplined, applying rigorous screens before they made an adjacency move. This discipline paid off in the form of learning curve benefits, increased speed, and lower complexity. And second, in almost all cases, they developed their repeatable formulas by studying their customers and their customers' economics very, very carefully.

  15. Core catcher for nuclear reactor core meltdown containment

    International Nuclear Information System (INIS)

    Driscoll, M.J.; Bowman, F.L.

    1978-01-01

    A bed of graphite particles is placed beneath a nuclear reactor core outside the pressure vessel but within the containment building to catch the core debris in the event of failure of the emergency core cooling system. Spray cooling of the debris and graphite particles together with draining and flooding of coolant fluid of the graphite bed is provided to prevent debris slump-through to the bottom of the bed

  16. Core Promoter Structure in the Oomycete Phytophthora infestans

    Science.gov (United States)

    McLeod, Adele; Smart, Christine D.; Fry, William E.

    2004-01-01

    We have investigated the core promoter structure of the oomycete Phytophthora infestans. The transcriptional start sites (TSS) of three previously characterized P. infestans genes, Piexo1, Piexo3, and Piendo1, were determined by primer extension analyses. The TSS regions were homologous to a previously identified 16-nucleotide (nt) core sequence that overlaps the TSS in most oomycete genes. The core promoter regions of Piexo1 and Piendo1 were investigated by using a transient protoplast expression assay and the reporter gene β-glucuronidase. Mutational analyses of the promoters of Piexo1 and Piendo1 showed that there is a putative core promoter element encompassing the TSS (−2 to + 5) that has high sequence and functional homology to a known core promoter element present in other eukaryotes, the initiator element (Inr). Downstream and flanking the Inr is a highly conserved oomycete promoter region (+7 to + 15), hereafter referred to as FPR (flanking promoter region), which is also important for promoter function. The importance of the 19-nt core promoter region (Inr and FPR) in Piexo1 and Piendo1 was further investigated through electrophoretic mobility shift assays (EMSA). The EMSA studies showed that (i) both core promoters were able to specifically bind a protein or protein complex in a P. infestans whole-cell protein extract and (ii) the same mutations that reduced binding of the EMSA complex also reduced β-glucuronidase (GUS) levels in transient expression assays. The consistency of results obtained using two different assays (GUS transient assays [in vivo] and EMSA studies [in vitro]) supports a convergence of inference about the relative importance of specific nucleotides within the 19-nt core promoter region. PMID:14871940

  17. AGR core safety assessment methodologies

    International Nuclear Information System (INIS)

    McLachlan, N.; Reed, J.; Metcalfe, M.P.

    1996-01-01

    To demonstrate the safety of its gas-cooled graphite-moderated AGR reactors, nuclear safety assessments of the cores are based upon a methodology which demonstrates no component failures, geometrical stability of the structure and material properties bounded by a database. All AGRs continue to meet these three criteria. However, predictions of future core behaviour indicate that the safety case methodology will eventually need to be modified to deal with new phenomena. A new approach to the safety assessment of the cores is currently under development, which can take account of these factors while at the same time providing the same level of protection for the cores. This approach will be based on the functionality of the core: unhindered movement of control rods, continued adequate cooling of the fuel and the core, continued ability to charge and discharge fuel. (author). 5 figs

  18. Overview of core disruptive accidents

    International Nuclear Information System (INIS)

    Marchaterre, J.F.

    1977-01-01

    An overview of the analysis of core-disruptive accidents is given. These analyses are for the purpose of understanding and predicting fast reactor behavior in severe low probability accident conditions, to establish the consequences of such conditions and to provide a basis for evaluating consequence limiting design features. The methods are used to analyze core-disruptive accidents from initiating event to complete core disruption, the effects of the accident on reactor structures and the resulting radiological consequences are described

  19. In Vitro-Assembled Alphavirus Core-Like Particles Maintain a Structure Similar to That of Nucleocapsid Cores in Mature Virus

    OpenAIRE

    Mukhopadhyay, Suchetana; Chipman, Paul R.; Hong, Eunmee M.; Kuhn, Richard J.; Rossmann, Michael G.

    2002-01-01

    In vitro-assembled core-like particles produced from alphavirus capsid protein and nucleic acid were studied by cryoelectron microscopy. These particles were found to have a diameter of 420 Å with 240 copies of the capsid protein arranged in a T=4 icosahedral surface lattice, similar to the nucleocapsid core in mature virions. However, when the particles were subjected to gentle purification procedures, they were damaged, preventing generation of reliable structural information. Similarly, pu...

  20. Coupling between core and cladding modes in a helical core fiber with large core offset

    International Nuclear Information System (INIS)

    Napiorkowski, Maciej; Urbanczyk, Waclaw

    2016-01-01

    We analyzed the effect of resonant coupling between core and cladding modes in a helical core fiber with large core offset using the fully vectorial method based on the transformation optics formalism. Our study revealed that the resonant couplings to lower order cladding modes predicted by perturbative methods and observed experimentally in fibers with small core offsets are in fact prohibited for larger core offsets. This effect is related to the lack of phase matching caused by elongation of the optical path of the fundamental modes in the helical core. Moreover, strong couplings to the cladding modes of the azimuthal modal number much higher than predicted by perturbative methods may be observed for large core offsets, as the core offset introduces higher order angular harmonics in the field distribution of the fundamental modes. Finally, in contrast to previous studies, we demonstrate the existence of spectrally broad polarization sensitive couplings to the cladding modes suggesting that helical core fibers with large core offsets may be used as broadband circular polarizers. (paper)

  1. Protein Correlation Profiles Identify Lipid Droplet Proteins with High Confidence*

    Science.gov (United States)

    Krahmer, Natalie; Hilger, Maximiliane; Kory, Nora; Wilfling, Florian; Stoehr, Gabriele; Mann, Matthias; Farese, Robert V.; Walther, Tobias C.

    2013-01-01

    Lipid droplets (LDs) are important organelles in energy metabolism and lipid storage. Their cores are composed of neutral lipids that form a hydrophobic phase and are surrounded by a phospholipid monolayer that harbors specific proteins. Most well-established LD proteins perform important functions, particularly in cellular lipid metabolism. Morphological studies show LDs in close proximity to and interacting with membrane-bound cellular organelles, including the endoplasmic reticulum, mitochondria, peroxisomes, and endosomes. Because of these close associations, it is difficult to purify LDs to homogeneity. Consequently, the confident identification of bona fide LD proteins via proteomics has been challenging. Here, we report a methodology for LD protein identification based on mass spectrometry and protein correlation profiles. Using LD purification and quantitative, high-resolution mass spectrometry, we identified LD proteins by correlating their purification profiles to those of known LD proteins. Application of the protein correlation profile strategy to LDs isolated from Drosophila S2 cells led to the identification of 111 LD proteins in a cellular LD fraction in which 1481 proteins were detected. LD localization was confirmed in a subset of identified proteins via microscopy of the expressed proteins, thereby validating the approach. Among the identified LD proteins were both well-characterized LD proteins and proteins not previously known to be localized to LDs. Our method provides a high-confidence LD proteome of Drosophila cells and a novel approach that can be applied to identify LD proteins of other cell types and tissues. PMID:23319140

  2. Models of the earth's core

    International Nuclear Information System (INIS)

    Stevenson, D.J.

    1981-01-01

    The combination of seismology, high pressure experiment and theory, geomagnetism, fluid dynamics, and current views of terrestrial planetary evolution lead to strong constraints on core models. The synthesis presented here is devoted to the defense of the following properties: (1) core formation was contemporaneous with earth accretion; (2) the outer, liquid core is predominately iron but cannot be purely iron; (3) the inner core-outer core boundary represents a thermodynamic equilibrium between a liquid alloys and a predominanately iron solid; (4) thermodynamic and transport properties of outer core can be estimated from liquid-state theories; and (5) the outer core is probably adiabatic and uniform in composition. None of these propositions are universally accepted by geophysicists. But, the intent of this paper is to present a coherent picture which explains most of the data with the fewest ad hoc assumptions. Areas in which future progress is both essential and likely are geo- and cosmochronology, seismological determinations of core structure, fluid dynamics of the core and mantle, and condensed matter physics

  3. Wire core reactor for NTP

    International Nuclear Information System (INIS)

    Harty, R.B.

    1991-01-01

    The development of the wire core system for Nuclear Thermal Propulsion (NTP) that took place from 1963 to 1965 is discussed. A wire core consists of a fuel wire with spacer wires. It's an annular flow core having a central control rod. There are actually four of these, with beryllium solid reflectors on both ends and all the way around. Much of the information on the concept is given in viewgraph form. Viewgraphs are presented on design details of the wire core, the engine design, engine weight vs. thrust, a technique used to fabricate the wire fuel element, and axial temperature distribution

  4. Nuclear reactor with several cores

    International Nuclear Information System (INIS)

    Swars, H.

    1977-01-01

    Several sodium-cooled cores in separate vessels with removable closures are placed in a common reactor tank. Each individual vessel is protected against the consequences of an accident in the relevant core. Maintenance devices and inlet and outlet pipes for the coolant are also arranged within the reactor tank. The individual vessels are all enclosed by coolant in a way that in case of emergency cooling or refuelling each core can be continued to be cooled by means of the coolant loops of the other cores. (HP) [de

  5. Biochemistry Instrumentation Core Technology Center

    Data.gov (United States)

    Federal Laboratory Consortium — The UCLA-DOE Biochemistry Instrumentation Core Facility provides the UCLA biochemistry community with easy access to sophisticated instrumentation for a wide variety...

  6. Core barrel inner tube lifter

    Energy Technology Data Exchange (ETDEWEB)

    Jeffers, J P

    1968-07-16

    A core drill with means for selectively lifting a core barrel inner tube consists of a lifting means connected to the core barrel inner tube assembly. It has a closable passage to permit drilling fluid normally to pass through it. The lifting means has a normally downward facing surface and a means to direct drilling fluid pressure against that surface so that on closure of the passage to fluid flow, the pressure of the drilling fluid is caused to act selectively on it. This causes the lifting means to rise and lift the core barrel. (7 claims)

  7. TMI-2 core debris analysis

    International Nuclear Information System (INIS)

    Cook, B.A.; Carlson, E.R.

    1985-01-01

    One of the ongoing examination tasks for the damaged TMI-2 reactor is analysis of samples of debris obtained from the debris bed presently at the top of the core. This paper summarizes the results reported in the TMI-2 Core Debris Grab Sample Examination and Analysis Report, which will be available early in 1986. The sampling and analysis procedures are presented, and information is provided on the key results as they relate to the present core condition, peak temperatures during the transient, temperature history, chemical interactions, and core relocation. The results are then summarized

  8. Meltdown reactor core cooling facility

    International Nuclear Information System (INIS)

    Matsuoka, Tsuyoshi.

    1992-01-01

    The meltdown reactor core cooling facility comprises a meltdown reactor core cooling tank, a cooling water storage tank situates at a position higher than the meltdown reactor core cooling tank, an upper pipeline connecting the upper portions of the both of the tanks and a lower pipeline connecting the lower portions of them. Upon occurrence of reactor core meltdown, a high temperature meltdown reactor core is dropped on the cooling tank to partially melt the tank and form a hole, from which cooling water is flown out. Since the water source of the cooling water is the cooling water storage tank, a great amount of cooling water is further dropped and supplied and the reactor core is submerged and cooled by natural convection for a long period of time. Further, when the lump of the meltdown reactor core is small and the perforated hole of the meltdown reactor cooling tank is small, cooling water is boiled by the high temperature lump intruding into the meltdown reactor core cooling tank and blown out from the upper pipeline to the cooling water storage tank to supply cooling water from the lower pipeline to the meltdown reactor core cooling tank. Since it is constituted only with simple static facilities, the facility can be simplified to attain improvement of reliability. (N.H.)

  9. Fort St. Vrain core performance

    International Nuclear Information System (INIS)

    McEachern, D.W.; Brown, J.R.; Heller, R.A.; Franek, W.J.

    1977-07-01

    The Fort St. Vrain High Temperature Gas Cooled Reactor core performance has been evaluated during the startup testing phase of the reactor operation. The reactor is graphite moderated, helium cooled, and uses coated particle fuel and on-line flow control to each of the 37 refueling regions. Principal objectives of startup testing were to determine: core and control system reactivity, radial power distribution, flow control capability, and initial fission product release. Information from the core demonstrates that Technical Specifications are being met, performance of the core and fuel is as expected, flow and reactivity control are predictable and simple for the operator to carry out

  10. HCV Core Residues Critical for Infectivity Are Also Involved in Core-NS5A Complex Formation

    Science.gov (United States)

    Gawlik, Katarzyna; Baugh, James; Chatterji, Udayan; Lim, Precious J.; Bobardt, Michael D.; Gallay, Philippe A.

    2014-01-01

    Hepatitis C virus (HCV) infection is a major cause of liver disease. The molecular machinery of HCV assembly and particle release remains obscure. A better understanding of the assembly events might reveal new potential antiviral strategies. It was suggested that the nonstructural protein 5A (NS5A), an attractive recent drug target, participates in the production of infectious particles as a result of its interaction with the HCV core protein. However, prior to the present study, the NS5A-binding site in the viral core remained unknown. We found that the D1 domain of core contains the NS5A-binding site with the strongest interacting capacity in the basic P38-K74 cluster. We also demonstrated that the N-terminal basic residues of core at positions 50, 51, 59 and 62 were required for NS5A binding. Analysis of all substitution combinations of R50A, K51A, R59A, and R62A, in the context of the HCVcc system, showed that single, double, triple, and quadruple mutants were fully competent for viral RNA replication, but deficient in secretion of viral particles. Furthermore, we found that the extracellular and intracellular infectivity of all the mutants was abolished, suggesting a defect in the formation of infectious particles. Importantly, we showed that the interaction between the single and quadruple core mutants and NS5A was impaired in cells expressing full-length HCV genome. Interestingly, mutations of the four basic residues of core did not alter the association of core or NS5A with lipid droplets. This study showed for the first time that basic residues in the D1 domain of core that are critical for the formation of infectious extracellular and intracellular particles also play a role in core-NS5A interactions. PMID:24533158

  11. SU-F-P-24: Radiological Disperse Device

    Energy Technology Data Exchange (ETDEWEB)

    Alam, R [NYC Dept of Health, NYC, NY (United States)

    2016-06-15

    Purpose: We are now living in a society of constant fear of terrorism. This topic is pertaining to give a general knowledge of what is a radiological dispersion device or RDD and in case of its detonation, what are the options open to public for a safe action in terms of reducing the exposure and knowing the proper steps. These RDD are also called dirty bombs. Methods: Compared to nuclear weapons, dirty bombs are easy to make. In order for a terrorist organization to construct and detonate a dirty bomb, it must acquire radioactive material by stealing it or buying it through legal or illegal channels. Possible RDD material could come from the millions of radioactive sources used in the industry, for medical purposes and in academic applications mainly for researches. These are, americium-{sup 241}, californium-{sup 252}, caesium-{sup 137}, cobalt-{sup 60}, iridium-{sup 192}, plutonium-{sup 238}, polonium-{sup 210}, radium-{sup 226} and strontium-{sup 90}. Results: Prompt detection of the type of radioactive material used will greatly assist advising people on the protective measures, like sheltering in place, or quickly leaving the immediate area. The effects of radiation are determined by:°the amount of radiation absorbed by body°the type of radiation °the distance from the radiation to an individual°the means of exposure absorbed by the skin, inhaled, or ingested; and length of time exposed. Conclusion: In any facility it is now much more important to keep a log list of all radioactive materials in use. In case there is a dirty bomb explosion, the chaos and economic cost could be enormous. The economic cost for the evaluation of the contamination, survey of people and surroundings and the after treatment, decontamination cost and effort will be a big challenge in any country. So awareness and preparation is the start to face this new type of challenge.

  12. Structural and functional aspects of winged-helix domains at the core of transcription initiation complexes.

    Science.gov (United States)

    Teichmann, Martin; Dumay-Odelot, Hélène; Fribourg, Sébastien

    2012-01-01

    The winged helix (WH) domain is found in core components of transcription systems in eukaryotes and prokaryotes. It represents a sub-class of the helix-turn-helix motif. The WH domain participates in establishing protein-DNA and protein-protein-interactions. Here, we discuss possible explanations for the enrichment of this motif in transcription systems.

  13. Characterizing the Core via K-Core Covers

    NARCIS (Netherlands)

    Sanchez, S.M.; Borm, P.E.M.; Estevez, A.

    2013-01-01

    This paper extends the notion of individual minimal rights for a transferable utility game (TU-game) to coalitional minimal rights using minimal balanced families of a specific type, thus defining a corresponding minimal rights game. It is shown that the core of a TU-game coincides with the core of

  14. Adult educators' core competences

    Science.gov (United States)

    Wahlgren, Bjarne

    2016-06-01

    Which competences do professional adult educators need? This research note discusses the topic from a comparative perspective, finding that adult educators' required competences are wide-ranging, heterogeneous and complex. They are subject to context in terms of national and cultural environment as well as the kind of adult education concerned (e.g. basic education, work-related education etc.). However, it seems that it is possible to identify certain competence requirements which transcend national, cultural and functional boundaries. This research note summarises these common or "core" requirements, organising them into four thematic subcategories: (1) communicating subject knowledge; (2) taking students' prior learning into account; (3) supporting a learning environment; and (4) the adult educator's reflection on his or her own performance. At the end of his analysis of different competence profiles, the author notes that adult educators' ability to train adult learners in a way which then enables them to apply and use what they have learned in practice (thus performing knowledge transfer) still seems to be overlooked.

  15. Emergency core cooling system

    International Nuclear Information System (INIS)

    Arai, Kenji; Oikawa, Hirohide.

    1990-01-01

    The device according to this invention can ensure cooling water required for emerency core cooling upon emergence such as abnormally, for example, loss of coolant accident, without using dynamic equipments such as a centrifugal pump or large-scaled tank. The device comprises a pressure accumulation tank containing a high pressure nitrogen gas and cooling water inside, a condensate storage tank, a pressure suppression pool and a jet stream pump. In this device there are disposed a pipeline for guiding cooling water in the pressure accumulation tank as a jetting water to a jetting stream pump, a pipeline for guiding cooling water stored in the condensate storage tank and the pressure suppression pool as pumped water to the jetting pump and, further, a pipeline for guiding the discharged water from the jet stream pump which is a mixed stream of pumped water and jetting water into the reactor pressure vessel. In this constitution, a sufficient amount of water ranging from relatively high pressure to low pressure can be supplied into the reactor pressure vessel, without increasing the size of the pressure accumulation tank. (I.S.)

  16. Emergency core cooling system

    International Nuclear Information System (INIS)

    Sato, Akira; Kobayashi, Masahide.

    1983-01-01

    Purpose: To enable a stable operation of an emergency core cooling system by preventing the system from the automatic stopping at an abnormally high level of the reactor water during its operation. Constitution: A pump flow rate signal and a reactor water level signal are used and, when the reactor water level is increased to a predetermined level, the pump flow rate is controlled by the reactor water level signal instead of the flow rate signal. Specifically, when the reactor water level is gradually increased by the water injection from the pump and exceeds a setting signal for the water level, the water level deviation signal acts as a demand signal for the decrease in the flow rate of the pump and the output signal from the water level controller is also decreased depending on the control constant. At a certain point, the output signal from the water level controller becomes smaller than the output signal from the flow rate controller. Thus, the output signal from the water level controller is outputted as the output signal for the lower level preference device. In this way, the reactor water level and the pump flow rate can be controlled within a range not exceeding the predetermined pump flow rate. (Horiuchi, T.)

  17. Emergency core cooling system

    International Nuclear Information System (INIS)

    Abe, Nobuaki.

    1993-01-01

    A reactor comprises a static emergency reactor core cooling system having an automatic depressurization system and a gravitationally dropping type water injection system and a container cooling system by an isolation condenser. A depressurization pipeline of the automatic depressurization system connected to a reactor pressure vessel branches in the midway. The branched depressurizing pipelines are extended into an upper dry well and a lower dry well, in which depressurization valves are disposed at the top end portions of the pipelines respectively. If loss-of-coolant accidents should occur, the depressurization valve of the automatic depressurization system is actuated by lowering of water level in the pressure vessel. This causes nitrogen gases in the upper and the lower dry wells to transfer together with discharged steams effectively to a suppression pool passing through a bent tube. Accordingly, the gravitationally dropping type water injection system can be actuated faster. Further, subsequent cooling for the reactor vessel can be ensured sufficiently by the isolation condenser. (I.N.)

  18. Necrosome core machinery: MLKL.

    Science.gov (United States)

    Zhang, Jing; Yang, Yu; He, Wenyan; Sun, Liming

    2016-06-01

    In the study of regulated cell death, the rapidly expanding field of regulated necrosis, in particular necroptosis, has been drawing much attention. The signaling of necroptosis represents a sophisticated form of a death pathway. Anti-caspase mechanisms (e.g., using inhibitors of caspases, or genetic ablation of caspase-8) switch cell fate from apoptosis to necroptosis. The initial extracellular death signals regulate RIP1 and RIP3 kinase activation. The RIP3-associated death complex assembly is necessary and sufficient to initiate necroptosis. MLKL was initially identified as an essential mediator of RIP1/RIP3 kinase-initiated necroptosis. Recent studies on the signal transduction using chemical tools and biomarkers support the idea that MLKL is able to make more functional sense for the core machinery of the necroptosis death complex, called the necrosome, to connect to the necroptosis execution. The experimental data available now have pointed that the activated MLKL forms membrane-disrupting pores causing membrane leakage, which extends the prototypical concept of morphological and biochemical events following necroptosis happening in vivo. The key role of MLKL in necroptosis signaling thus sheds light on the logic underlying this unique "membrane-explosive" cell death pathway. In this review, we provide the general concepts and strategies that underlie signal transduction of this form of cell death, and then focus specifically on the role of MLKL in necroptosis.

  19. The core proteome and pan proteome of Salmonella Paratyphi A epidemic strains.

    Directory of Open Access Journals (Sweden)

    Li Zhang

    Full Text Available Comparative proteomics of the multiple strains within the same species can reveal the genetic variation and relationships among strains without the need to assess the genomic data. Similar to comparative genomics, core proteome and pan proteome can also be obtained within multiple strains under the same culture conditions. In this study we present the core proteome and pan proteome of four epidemic Salmonella Paratyphi A strains cultured under laboratory culture conditions. The proteomic information was obtained using a Two-dimensional gel electrophoresis (2-DE technique. The expression profiles of these strains were conservative, similar to the monomorphic genome of S. Paratyphi A. Few strain-specific proteins were found in these strains. Interestingly, non-core proteins were found in similar categories as core proteins. However, significant fluctuations in the abundance of some core proteins were also observed, suggesting that there is elaborate regulation of core proteins in the different strains even when they are cultured in the same environment. Therefore, core proteome and pan proteome analysis of the multiple strains can demonstrate the core pathways of metabolism of the species under specific culture conditions, and further the specific responses and adaptations of the strains to the growth environment.

  20. Core Gene Expression and Association of Genotypes with Viral ...

    African Journals Online (AJOL)

    HP

    Fukutomi T, Zhou Y, Kawai S, Eguchi H, Wands JR, Li J. Hepatitis C virus core protein stimulates hepatocyte growth: correlation with up regulation of wnt-1 expression. Hepatology. 2005; 41: 1096-1105. 5. Raja NS, Janjua KA. Epidemiology of hepatitis C virus infection in Pakistan. J. Microbiol. Immunol. Infect. 2008; 41: 4–8.

  1. Core-to-core uniformity improvement in multi-core fiber Bragg gratings

    Science.gov (United States)

    Lindley, Emma; Min, Seong-Sik; Leon-Saval, Sergio; Cvetojevic, Nick; Jovanovic, Nemanja; Bland-Hawthorn, Joss; Lawrence, Jon; Gris-Sanchez, Itandehui; Birks, Tim; Haynes, Roger; Haynes, Dionne

    2014-07-01

    Multi-core fiber Bragg gratings (MCFBGs) will be a valuable tool not only in communications but also various astronomical, sensing and industry applications. In this paper we address some of the technical challenges of fabricating effective multi-core gratings by simulating improvements to the writing method. These methods allow a system designed for inscribing single-core fibers to cope with MCFBG fabrication with only minor, passive changes to the writing process. Using a capillary tube that was polished on one side, the field entering the fiber was flattened which improved the coverage and uniformity of all cores.

  2. Calcium ions affect the hepatitis B virus core assembly

    International Nuclear Information System (INIS)

    Choi, Yongwook; Gyoo Park, Sung; Yoo, Jun-hi; Jung, Guhung

    2005-01-01

    Previous report showed that cytosolic Ca 2+ induced by hepatitis B virus X protein (HBx) promotes HBV replication. In this study, in vitro experiments showed that (i) HBV core assembly in vitro was promoted by Ca 2+ through the sucrose density gradient and the analytical ultracentrifuge analysis. Also (ii) transmission electron microscope analysis demonstrated these assembled HBV core particles were the capsids. Ex vivo experiments showed that the treatment of BAPTA-AM and cyclosporine A (CsA) reduced HBV capsids in the transfected HepG2 cells. In addition to that, the treatment of Thapsigargin (TG) increased HBV capsids in the transfected HepG2 cells. Furthermore, we investigated the increased HBV core assembly by HBx. The results show that the increased cytosolic calcium ions by HBx promote the HBV core assembly

  3. Nuclear reactor core stabilizing arrangement

    International Nuclear Information System (INIS)

    Jabsen, F.S.

    1976-01-01

    A nuclear reactor core stabilizing arrangement is described wherein a plurality of actuators, disposed in a pattern laterally surrounding a group of elongated fuel assemblies, press against respective contiguous fuel assemblies on the periphery of the group to reduce the clearance between adjacent fuel assemblies thereby forming a more compacted, vibration resistant core structure. 7 claims, 4 drawing figures

  4. Complicated Politics to the Core

    Science.gov (United States)

    McGuinn, Patrick

    2015-01-01

    People dislike the Common Core for several different reasons, and so it is important to disaggregate the sources of opposition and to assess and then to dispel some of the myths that have built up around it. It also is important to understand the unusual political alliances that have emerged in opposition to Common Core implementation and how they…

  5. Toward full MOX core design

    International Nuclear Information System (INIS)

    Rouviere, G.; Guillet, J.L.; Bruna, G.B.; Pelet, J.

    1999-01-01

    This paper presents a selection of the main preliminary results of a study program sponsored by COGEMA and currently carried out by FRAMATOME. The objective of this study is to investigate the feasibility of full MOX core loading in a French 1300 MWe PWR, a recent and widespread standard nuclear power plant. The investigation includes core nuclear design, thermal hydraulic and systems aspects. (authors)

  6. Collapsing stellar cores and supernovae

    Energy Technology Data Exchange (ETDEWEB)

    Epstein, R J [Nordisk Inst. for Teoretisk Atomfysik, Copenhagen (Denmark); Noorgaard, H [Nordisk Inst. for Teoretisk Atomfysik, Copenhagen (Denmark); Chicago Univ., IL (USA). Enrico Fermi Inst.); Bond, J R [Niels Bohr Institutet, Copenhagen (Denmark); California Inst. of Tech., Pasadena (USA). W.K. Kellogg Radiation Lab.)

    1979-05-01

    The evolution of a stellar core is studied during its final quasi-hydrostatic contraction. The core structure and the (poorly known) properties of neutron rich matter are parametrized to include most plausible cases. It is found that the density-temperature trajectory of the material in the central part of the core (the core-center) is insensitive to nearly all reasonable parameter variations. The central density at the onset of the dynamic phase of the collapse (when the core-center begins to fall away from the rest of the star) and the fraction of the emitted neutrinos which are trapped in the collapsing core-center depend quite sensitively on the properties of neutron rich matter. We estimate that the amount of energy Ecm which is imparted to the core-mantle by the neutrinos which escape from the imploded core-center can span a large range of values. For plausible choices of nuclear and model parameters Ecm can be large enough to yield a supernova event.

  7. The INTEGRAL Core Observing Programme

    DEFF Research Database (Denmark)

    Winkler, C.; Gehrels, N.; Lund, Niels

    1999-01-01

    The Core Programme of the INTEGRAL mission is defined as the portion of the scientific programme covering the guaranteed time observations for the INTEGRAL Science Working Team. This paper describes the current status of the Core Programme preparations and summarizes the key elements...... of the observing programme....

  8. Core barrel plug

    International Nuclear Information System (INIS)

    Tolino, R.W.; Hopkins, R.J.; Congleton, R.L.; Popalis, C.H.

    1986-01-01

    A plug is described for preventing flow through a port in a core barrel of a pressurized water nuclear reactor which consists of: a substantially cylindrical body formed with a cylindrical portion and a flange and defining a tapered leading open end with the other end being closed by an end plug attached to the flange, the body defining a bore therein extending from the open end to the end plug with the bore having a smaller diameter near the open end than near the end plug, the cylindrical portion having a lip near the open end and being formed with longitudinal slots extending from the open end toward the flange and extending entirely through the thickness of the cylindrical portion, the cylindrical portion having a circumferential first groove on the outer surface thereof located near the forwardmost portion of the cylindrical portion but not in the section of the cylindrical portion that has the slots therein, and a plurality of circumferential second grooves on the outer surface thereof located in the section of the cylindrical portion that has the slots therein, the first and second grooves establishing a seal between the cylindrical portion and the inside surface of the port when the cylindrical portion is expanded, and the flange and the end plug having a passageway defined therein for introducing a fluid into the body; a metal ring disposed in each of the second grooves; a mandrel slidably disposed and captured in the body and capable of being moved toward the open end of the body when the fluid is introduced through the passageway, thereby causing the cylindrical portion to be expanded into contact with the inside surface of the port; and a locking mechanism disposed in the end plug for preventing inadvertent movement of the mandrel

  9. SCORPIO - VVER core surveillance system

    International Nuclear Information System (INIS)

    Zalesky, K.; Svarny, J.; Novak, L.; Rosol, J.; Horanes, A.

    1997-01-01

    The Halden Project has developed the core surveillance system SCORPIO which has two parallel modes of operation: the Core Follow Mode and the Predictive Mode. The main motivation behind the development of SCORPIO is to make a practical tool for reactor operators which can increase the quality and quantity of information presented on core status and dynamic behavior. This can first of all improve plant safety as undesired core conditions are detected and prevented. Secondly, more flexible and efficient plant operation is made possible. So far the system has only been implemented on western PWRs but the basic concept is applicable to a wide range of reactor including WWERs. The main differences between WWERs and typical western PWRs with respect to core surveillance requirements are outlined. The development of a WWER version of SCORPIO was initiated in cooperation with the Nuclear Research Institute at Rez and industry partners in the Czech Republic. The first system will be installed at the Dukovany NPP. (author)

  10. Core body temperature in obesity.

    Science.gov (United States)

    Heikens, Marc J; Gorbach, Alexander M; Eden, Henry S; Savastano, David M; Chen, Kong Y; Skarulis, Monica C; Yanovski, Jack A

    2011-05-01

    A lower core body temperature set point has been suggested to be a factor that could potentially predispose humans to develop obesity. We tested the hypothesis that obese individuals have lower core temperatures than those in normal-weight individuals. In study 1, nonobese [body mass index (BMI; in kg/m(2)) temperature-sensing capsules, and we measured core temperatures continuously for 24 h. In study 2, normal-weight (BMI of 18-25) and obese subjects swallowed temperature-sensing capsules to measure core temperatures continuously for ≥48 h and kept activity logs. We constructed daily, 24-h core temperature profiles for analysis. Mean (±SE) daily core body temperature did not differ significantly between the 35 nonobese and 46 obese subjects (36.92 ± 0.03°C compared with 36.89 ± 0.03°C; P = 0.44). Core temperature 24-h profiles did not differ significantly between 11 normal-weight and 19 obese subjects (P = 0.274). Women had a mean core body temperature ≈0.23°C greater than that of men (36.99 ± 0.03°C compared with 36.76 ± 0.03°C; P body temperature. It may be necessary to study individuals with function-altering mutations in core temperature-regulating genes to determine whether differences in the core body temperature set point affect the regulation of human body weight. These trials were registered at clinicaltrials.gov as NCT00428987 and NCT00266500.

  11. Epistemology and ontology in core ontologies: FOLaw and LRI-Core, two core ontologies for law

    NARCIS (Netherlands)

    Breukers, J.A.P.J.; Hoekstra, R.J.

    2004-01-01

    For more than a decade constructing ontologies for legal domains, we, at the Leibniz Center for Law, felt really the need to develop a core ontology for law that would enable us to re-use the common denominator of the various legal domains. In this paper we present two core ontologies for law. The

  12. HOW STARLESS ARE STARLESS CORES?

    International Nuclear Information System (INIS)

    Schnee, Scott; Friesen, Rachel; Di Francesco, James; Johnstone, Doug; Enoch, Melissa; Sadavoy, Sarah

    2012-01-01

    In this paper, we present the results of Combined Array for Research in Millimeter-wave Astronomy continuum and spectral line observations of the dense core Per-Bolo 45. Although this core has previously been classified as starless, we find evidence for an outflow and conclude that Per-Bolo 45 is actually an embedded, low-luminosity protostar. We discuss the impact of newly discovered, low-luminosity, embedded objects in the Perseus molecular cloud on starless core and protostar lifetimes. We estimate that the starless core lifetime has been overestimated by 4%-18% and the Class 0/I protostellar lifetime has been underestimated by 5%-20%. Given the relatively large systematic uncertainties involved in these calculations, variations on the order of 10% do not significantly change either core lifetimes or the expected protostellar luminosity function. Finally, we suggest that high-resolution (sub)millimeter surveys of known cores lacking near-infrared and mid-infrared emission are necessary to make an accurate census of starless cores.

  13. Challenges for proteomics core facilities.

    Science.gov (United States)

    Lilley, Kathryn S; Deery, Michael J; Gatto, Laurent

    2011-03-01

    Many analytical techniques have been executed by core facilities established within academic, pharmaceutical and other industrial institutions. The centralization of such facilities ensures a level of expertise and hardware which often cannot be supported by individual laboratories. The establishment of a core facility thus makes the technology available for multiple researchers in the same institution. Often, the services within the core facility are also opened out to researchers from other institutions, frequently with a fee being levied for the service provided. In the 1990s, with the onset of the age of genomics, there was an abundance of DNA analysis facilities, many of which have since disappeared from institutions and are now available through commercial sources. Ten years on, as proteomics was beginning to be utilized by many researchers, this technology found itself an ideal candidate for being placed within a core facility. We discuss what in our view are the daily challenges of proteomics core facilities. We also examine the potential unmet needs of the proteomics core facility that may also be applicable to proteomics laboratories which do not function as core facilities. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Core principles of evolutionary medicine

    Science.gov (United States)

    Grunspan, Daniel Z; Nesse, Randolph M; Barnes, M Elizabeth; Brownell, Sara E

    2018-01-01

    Abstract Background and objectives Evolutionary medicine is a rapidly growing field that uses the principles of evolutionary biology to better understand, prevent and treat disease, and that uses studies of disease to advance basic knowledge in evolutionary biology. Over-arching principles of evolutionary medicine have been described in publications, but our study is the first to systematically elicit core principles from a diverse panel of experts in evolutionary medicine. These principles should be useful to advance recent recommendations made by The Association of American Medical Colleges and the Howard Hughes Medical Institute to make evolutionary thinking a core competency for pre-medical education. Methodology The Delphi method was used to elicit and validate a list of core principles for evolutionary medicine. The study included four surveys administered in sequence to 56 expert panelists. The initial open-ended survey created a list of possible core principles; the three subsequent surveys winnowed the list and assessed the accuracy and importance of each principle. Results Fourteen core principles elicited at least 80% of the panelists to agree or strongly agree that they were important core principles for evolutionary medicine. These principles over-lapped with concepts discussed in other articles discussing key concepts in evolutionary medicine. Conclusions and implications This set of core principles will be helpful for researchers and instructors in evolutionary medicine. We recommend that evolutionary medicine instructors use the list of core principles to construct learning goals. Evolutionary medicine is a young field, so this list of core principles will likely change as the field develops further. PMID:29493660

  15. Protein Adaptations in Archaeal Extremophiles

    Science.gov (United States)

    Reed, Christopher J.; Lewis, Hunter; Trejo, Eric; Winston, Vern; Evilia, Caryn

    2013-01-01

    Extremophiles, especially those in Archaea, have a myriad of adaptations that keep their cellular proteins stable and active under the extreme conditions in which they live. Rather than having one basic set of adaptations that works for all environments, Archaea have evolved separate protein features that are customized for each environment. We categorized the Archaea into three general groups to describe what is known about their protein adaptations: thermophilic, psychrophilic, and halophilic. Thermophilic proteins tend to have a prominent hydrophobic core and increased electrostatic interactions to maintain activity at high temperatures. Psychrophilic proteins have a reduced hydrophobic core and a less charged protein surface to maintain flexibility and activity under cold temperatures. Halophilic proteins are characterized by increased negative surface charge due to increased acidic amino acid content and peptide insertions, which compensates for the extreme ionic conditions. While acidophiles, alkaliphiles, and piezophiles are their own class of Archaea, their protein adaptations toward pH and pressure are less discernible. By understanding the protein adaptations used by archaeal extremophiles, we hope to be able to engineer and utilize proteins for industrial, environmental, and biotechnological applications where function in extreme conditions is required for activity. PMID:24151449

  16. Protein Adaptations in Archaeal Extremophiles

    Directory of Open Access Journals (Sweden)

    Christopher J. Reed

    2013-01-01

    Full Text Available Extremophiles, especially those in Archaea, have a myriad of adaptations that keep their cellular proteins stable and active under the extreme conditions in which they live. Rather than having one basic set of adaptations that works for all environments, Archaea have evolved separate protein features that are customized for each environment. We categorized the Archaea into three general groups to describe what is known about their protein adaptations: thermophilic, psychrophilic, and halophilic. Thermophilic proteins tend to have a prominent hydrophobic core and increased electrostatic interactions to maintain activity at high temperatures. Psychrophilic proteins have a reduced hydrophobic core and a less charged protein surface to maintain flexibility and activity under cold temperatures. Halophilic proteins are characterized by increased negative surface charge due to increased acidic amino acid content and peptide insertions, which compensates for the extreme ionic conditions. While acidophiles, alkaliphiles, and piezophiles are their own class of Archaea, their protein adaptations toward pH and pressure are less discernible. By understanding the protein adaptations used by archaeal extremophiles, we hope to be able to engineer and utilize proteins for industrial, environmental, and biotechnological applications where function in extreme conditions is required for activity.

  17. Assessing Core Competencies

    Science.gov (United States)

    Narayanan, M.

    2004-12-01

    Catherine Palomba and Trudy Banta offer the following definition of assessment, adapted from one provided by Marches in 1987. Assessment in the systematic collection, review, and use of information about educational programs undertaken for the purpose of improving student learning and development. (Palomba and Banta 1999). It is widely recognized that sophisticated computing technologies are becoming a key element in today's classroom instructional techniques. Regardless, the Professor must be held responsible for creating an instructional environment in which the technology actually supplements learning outcomes of the students. Almost all academic disciplines have found a niche for computer-based instruction in their respective professional domain. In many cases, it is viewed as an essential and integral part of the educational process. Educational institutions are committing substantial resources to the establishment of dedicated technology-based laboratories, so that they will be able to accommodate and fulfill students' desire to master certain of these specific skills. This type of technology-based instruction may raise some fundamental questions about the core competencies of the student learner. Some of the most important questions are : 1. Is the utilization of these fast high-powered computers and user-friendly software programs creating a totally non-challenging instructional environment for the student learner ? 2. Can technology itself all too easily overshadow the learning outcomes intended ? 3. Are the educational institutions simply training students how to use technology rather than educating them in the appropriate field ? 4. Are we still teaching content-driven courses and analysis oriented subject matter ? 5. Are these sophisticated modern era technologies contributing to a decline in the Critical Thinking Capabilities of the 21st century technology-savvy students ? The author tries to focus on technology as a tool and not on the technology

  18. Performance evaluation of the Bio-Rad Laboratories GS HIV Combo Ag/Ab EIA, a 4th generation HIV assay for the simultaneous detection of HIV p24 antigen and antibodies to HIV-1 (groups M and O) and HIV-2 in human serum or plasma.

    Science.gov (United States)

    Bentsen, Christopher; McLaughlin, Lisa; Mitchell, Elizabeth; Ferrera, Carol; Liska, Sally; Myers, Robert; Peel, Sheila; Swenson, Paul; Gadelle, Stephane; Shriver, M Kathleen

    2011-12-01

    A multi-center study was conducted to evaluate the Bio-Rad GS HIV Combo Ag/Ab EIA, a 4th generation HIV-1/HIV-2 assay for the simultaneous detection of HIV p24 antigen and antibodies to HIV-1 (groups M and O) and HIV-2 in human serum or plasma in adult and pediatric populations. The objectives of the study were to assess assay performance for the detection of acute HIV infections; sensitivity in known HIV positive samples; percent agreement with HIV status; specificity in low and high risk individuals of unknown HIV status; and to compare assay performance to a 3rd generation HIV assay. The evaluation included testing 9150 samples at four U.S. clinical trial sites, using three kit lots. Unlinked samples were from routine testing, repositories or purchased from vendors. GS HIV Combo Ag/Ab EIA detection in samples from individuals in two separate populations with acute HIV infection was 95.2% (20/21) and 86.4% (38/44). Sensitivity was 100% (1603/1603) in known antibody positive [HIV-1 Groups M and O, and HIV-2] samples. HIV p24 antigen detection was 100% (53/53) in HIV-1 culture supernatants. HIV-1 seroconversion panel detection improved by a range of 0-20 days compared to a 3rd generation HIV test. Specificity was 99.9% (5989/5996) in low risk, 99.9% (959/960) in high risk and 100% (100/100) in pediatric populations. The GS HIV Combo Ag/Ab EIA significantly reduced the diagnostic window when compared to the 3rd generation screening assay, enabling earlier diagnosis of HIV infection. The performance parameters of the Bio-Rad GS HIV Combo Ag/Ab EIA are well suited for use in HIV diagnostic settings. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. SpaceCube Core Software

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop a flexible, modular and user friendly SpaceCube Core Software system that will dramatically simplify SpaceCube application development and enable any...

  20. Viral Evolution Core | FNLCR Staging

    Science.gov (United States)

    Brandon F. Keele, Ph.D. PI/Senior Principal Investigator, Retroviral Evolution Section Head, Viral Evolution Core Leidos Biomedical Research, Inc. Frederick National Laboratory for Cancer Research Frederick, MD 21702-1201 Tel: 301-846-173

  1. Computed tomography of drill cores

    International Nuclear Information System (INIS)

    Taylor, T.

    1985-08-01

    A preliminary computed tomography evaluation of drill cores of granite and sandstone has generated geologically significant data. Density variations as small as 4 percent and fractures as narrow as 0.1 mm were easily detected

  2. In-core monitoring detectors

    International Nuclear Information System (INIS)

    Mitelman, M.G.

    2001-01-01

    The main task of in-core monitoring consists in securing observability of the reactor installation in all possible operation modes (normal, transient, accident and post-accident). Operation safety at acceptable cost can be achieved by optimized measurement errors. The range of sensors applied as in-core detectors for operative measurements in the industry is very limited in number. Among them might be cited self powered neutron detectors (SPND) and thermocouples. Sensors are incorporated in the in-core detectors assemblies (SVRD). The presentation makes an effort to touch upon the problems of assuring and increasing quality of in-core on-line measurements. So we do not consider systems using movable detectors, as the latter do not assure on-line measurements. (Authors)

  3. Discovering the Army's Core Competencies

    National Research Council Canada - National Science Library

    Rudesheim, Frederick

    2001-01-01

    This paper seeks to answer the question, "Has the Army correctly identified its core competencies to ensure the Army can adequately respond to the national military strategy?" FM 1, The Army (Prototype Draft...

  4. Recriticality analyses for CAPRA cores

    International Nuclear Information System (INIS)

    Maschek, W.; Thiem, D.

    1995-01-01

    The first scoping calculation performed show that the energetics levels from recriticalities in CAPRA cores are in the same range as in conventional cores. However, considerable uncertainties exist and further analyses are necessary. Additional investigations are performed for the separation scenarios of fuel/steel/inert and matrix material as a large influence of these processes on possible ramp rates and kinetics parameters was detected in the calculations. (orig./HP)

  5. Recriticality analyses for CAPRA cores

    Energy Technology Data Exchange (ETDEWEB)

    Maschek, W.; Thiem, D.

    1995-08-01

    The first scoping calculation performed show that the energetics levels from recriticalities in CAPRA cores are in the same range as in conventional cores. However, considerable uncertainties exist and further analyses are necessary. Additional investigations are performed for the separation scenarios of fuel/steel/inert and matrix material as a large influence of these processes on possible ramp rates and kinetics parameters was detected in the calculations. (orig./HP)

  6. One dimensional reactor core model

    International Nuclear Information System (INIS)

    Kostadinov, V.; Stritar, A.; Radovo, M.; Mavko, B.

    1984-01-01

    The one dimensional model of neutron dynamic in reactor core was developed. The core was divided in several axial nodes. The one group neutron diffusion equation for each node is solved. Feedback affects of fuel and water temperatures is calculated. The influence of xenon, boron and control rods is included in cross section calculations for each node. The system of equations is solved implicitly. The model is used in basic principle Training Simulator of NPP Krsko. (author)

  7. Improvements to core-catchers

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, T C.W.

    1969-07-22

    A core catcher consists of a generally annular holder adapted to be contained within a core barrel with sets of dogs circumferentially disposed in the holder. Each set of dogs consists of at least 2 dogs of different lengths pivotally mounted in the holder to swing inward. The dogs in each set are vertically superimposed. They are of upward decreasing length, with the arc of swing of the vertically adjacent dogs overlapping. (8 claims)

  8. Nanoporous polymer liquid core waveguides

    DEFF Research Database (Denmark)

    Gopalakrishnan, Nimi; Christiansen, Mads Brøkner; Ndoni, Sokol

    2010-01-01

    We demonstrate liquid core waveguides defined by UV to enable selective water infiltration in nanoporous polymers, creating an effective refractive index shift Δn=0.13. The mode confinement and propagation loss in these waveguides are presented.......We demonstrate liquid core waveguides defined by UV to enable selective water infiltration in nanoporous polymers, creating an effective refractive index shift Δn=0.13. The mode confinement and propagation loss in these waveguides are presented....

  9. LMFBR Ultra Long Life Cores

    International Nuclear Information System (INIS)

    Schmidt, J.E.; Doncals, R.A.; Porter, C.A.; Gundy, L.M.

    1986-01-01

    The Ultra Long Life Core is an attractive and innovative design approach with several extremely beneficial attributes. Long Life cores are applicable to the full range of LMR plant sizes resulting in lifetimes up to 30 years. Core life is somewhat limited for smaller plant sizes, however significant benefits of this approach still exist for all plant sizes. The union of long life cores and the complementary inherent safety technology offer a means of utilizing the well-proven oxide fuel in a system with unsurpassed safety capability. A further benefit is that the uranium fuel cycle can be used in long life cores, especially for initial LMR plant deployment, thereby eliminating the need for reprocessing prior to starting LMR plant construction in the U.S. Finally the long life core significantly reduces power costs. With inherent safety capability designed into an LMR and with the ULLC fuel cycle, power costs competitive with light water plants are achievable while offering improved operational flexibility derived through extending refueling intervals

  10. TMI-2 core boring machine

    International Nuclear Information System (INIS)

    Croft, K.M.; Helbert, H.J.; Laney, W.M.

    1986-01-01

    An important and essential aspect of the TMI-2 defueling effort is to determine what occurred in the core region during the accident. Remote cameras and probes only portray a portion of the overall picture. What lies beneath the rubble bed and solidified sublayer is, as yet, unknown. This paper discusses the TMI-2 Core Boring Machine, which has been developed to drill into the damaged core of the TMI-2 reactor and extract stratified samples of the core. This machine, its unique support structure, positioning and leveling systems, and specially designed drill bits, combine to provide a unique mechanical system. In addition, the machine is controlled by a microprocessor; which actually controls the drilling operation, allowing relatively inexperienced operators to drill the core samples. A data acquisition system is data integral with the controlling system and collects data relative to system conditions and monitored parameters during drilling. Data obtained during the actual drilling operations are collected in a data base which will be used for actual mapping of the core region, identifying materials and stratification levels that are present

  11. Reactor core performance calculating device

    International Nuclear Information System (INIS)

    Tominaga, Kenji; Bando, Masaru; Sano, Hiroki; Maruyama, Hiromi.

    1995-01-01

    The device of the present invention can calculate a power distribution efficiently at high speed by a plurality of calculation means while taking an amount of the reactor state into consideration. Namely, an input device takes data from a measuring device for the amount of the reactor core state such as a large number of neutron detectors disposed in the reactor core for monitoring the reactor state during operation. An input data distribution device comprises a state recognition section and a data distribution section. The state recognition section recognizes the kind and amount of the inputted data and information of the calculation means. The data distribution section analyzes the characteristic of the inputted data, divides them into a several groups, allocates them to each of the calculation means for the purpose of calculating the reactor core performance efficiently at high speed based on the information from the state recognition section. A plurality of the calculation means calculate power distribution of each of regions based on the allocated inputted data, to determine the power distribution of the entire reactor core. As a result, the reactor core can be evaluated at high accuracy and at high speed irrespective of the whole reactor core or partial region. (I.S.)

  12. Core cooling system for reactor

    International Nuclear Information System (INIS)

    Kondo, Ryoichi; Amada, Tatsuo.

    1976-01-01

    Purpose: To improve the function of residual heat dissipation from the reactor core in case of emergency by providing a secondary cooling system flow channel, through which fluid having been subjected to heat exchange with the fluid flowing in a primary cooling system flow channel flows, with a core residual heat removal system in parallel with a main cooling system provided with a steam generator. Constitution: Heat generated in the core during normal reactor operation is transferred from a primary cooling system flow channel to a secondary cooling system flow channel through a main heat exchanger and then transferred through a steam generator to a water-steam system flow channel. In the event if removal of heat from the core by the main cooling system becomes impossible due to such cause as breakage of the duct line of the primary cooling system flow channel or a trouble in a primary cooling system pump, a flow control valve is opened, and steam generator inlet and outlet valves are closed, thus increasing the flow rate in the core residual heat removal system. Thereafter, a blower is started to cause dissipation of the core residual heat from the flow channel of a system for heat dissipation to atmosphere. (Seki, T.)

  13. Clustered epitopes within the Gag-Pol fusion protein DNA vaccine enhance immune responses and protection against challenge with recombinant vaccinia viruses expressing HIV-1 Gag and Pol antigens

    International Nuclear Information System (INIS)

    Bolesta, Elizabeth; Gzyl, Jaroslaw; Wierzbicki, Andrzej; Kmieciak, Dariusz; Kowalczyk, Aleksandra; Kaneko, Yutaro; Srinivasan, Alagarsamy; Kozbor, Danuta

    2005-01-01

    We have generated a codon-optimized hGagp17p24-Polp51 plasmid DNA expressing the human immunodeficiency virus type 1 (HIV-1) Gag-Pol fusion protein that consists of clusters of highly conserved cytotoxic T lymphocyte (CTL) epitopes presented by multiple MHC class I alleles. In the hGagp17p24-Polp51 construct, the ribosomal frameshift site had been deleted together with the potentially immunosuppressive Gag nucleocapsid (p15) as well as Pol protease (p10) and integrase (p31). Analyses of the magnitude and breadth of cellular responses demonstrated that immunization of HLA-A2/K b transgenic mice with the hGagp17p24-Polp51 construct induced 2- to 5-fold higher CD8 + T-cell responses to Gag p17-, p24-, and Pol reverse transcriptase (RT)-specific CTL epitopes than the full-length hGag-PolΔFsΔPr counterpart. The increases were correlated with higher protection against challenge with recombinant vaccinia viruses (rVVs) expressing gag and pol gene products. Consistent with the profile of Gag- and Pol-specific CD8 + T cell responses, an elevated level of type 1 cytokine production was noted in p24- and RT-stimulated splenocyte cultures established from hGagp17p24-Polp51-immunized mice compared to responses induced with the hGag-PolΔFsΔPr vaccine. Sera of mice immunized with the hGagp17p24-Polp51 vaccine also exhibited an increased titer of p24- and RT-specific IgG2 antibody responses. The results from our studies provide insights into approaches for boosting the breadth of Gag- and Pol-specific immune responses

  14. Fusion protein of tapasin and hepatitis B core antigen 18‑27 enhances T helper cell type 1/2 cytokine ratio and antiviral immunity by inhibiting suppressors of cytokine signaling family members 1/3 in hepatitis B virus transgenic mice.

    Science.gov (United States)

    Tang, Yuyan; Chen, Xiaohua; Zhang, Yi; Tang, Zhenghao; Zhuo, Meng; Li, Dan; Wang, Peng; Zang, Guoqing; Yu, Yongsheng

    2014-04-01

    Persistent hepatitis B virus (HBV) infection is characterized by a weak adaptive immune response, which is considered to be due to an imbalance of T helper cell types 1 and 2 (Th1/Th2). Suppressors of cytokine signaling (SOCS) family members, particularly SOCS1 and SOCS3, have been demonstrated to be important in the regulation of T cell differentiation. Previous studies by our group showed that the expressed and purified fusion protein of cytoplasmic transduction peptide (CTP) and HBV core antigen 18‑27 (HBcAg18‑27)‑tapasin was able to enter the cytoplasm of bone marrow‑derived dendritic cells (BMDCs), promoting the maturation of BMDCs and efficiently enhancing T cell immune responses in vitro. In the present study, HBcAg‑specific immune responses induced by CTP‑HBcAg18‑27‑tapasin in HBV were assessed in transgenic mice, and SOCS1 and SOCS3 were identified as negative regulators of this response. The Th1/Th2 cytokine ratio was analyzed by ELISA. The expression of T cell‑specific T‑box transcription factor (T‑bet) and GATA‑binding protein 3 (GATA‑3), SOCS1 and SOCS3 were detected by real‑time quantitative polymerase chain reaction and western blot analysis. The results demonstrated that CTP‑HBcAg18‑27‑tapasin significantly increased the Th1/Th2 cytokine ratio in HBV transgenic mice. CTP‑HBcAg18‑27‑tapasin immunization more efficiently suppressed the expression of serum hepatitis B surface antigen (HBsAg), HBV DNA as well as liver HBsAg and HBcAg in HBV transgenic mice. Furthermore, CTP‑HBcAg18‑27‑tapasin promotes T‑bet but reduces GATA‑3 expression. In addition, the expression of SOCS1 and SOCS3 was significantly downregulated in the CTP‑HBcAg18‑27‑tapasin group compared with the control groups. In conclusion, the present study demonstrated that CTP‑HBcAg18‑27‑tapasin enhanced the Th1/Th2 cytokine ratio and antiviral immunity by suppressing SOCS1/3 in HBV transgenic mice.

  15. Reactor core performance estimating device

    International Nuclear Information System (INIS)

    Tanabe, Akira; Yamamoto, Toru; Shinpuku, Kimihiro; Chuzen, Takuji; Nishide, Fusayo.

    1995-01-01

    The present invention can autonomously simplify a neural net model thereby enabling to conveniently estimate various amounts which represents reactor core performances by a simple calculation in a short period of time. Namely, a reactor core performance estimation device comprises a nerve circuit net which divides the reactor core into a large number of spacial regions, and receives various physical amounts for each region as input signals for input nerve cells and outputs estimation values of each amount representing the reactor core performances as output signals of output nerve cells. In this case, the nerve circuit net (1) has a structure of extended multi-layered model having direct coupling from an upper stream layer to each of downstream layers, (2) has a forgetting constant q in a corrected equation for a joined load value ω using an inverse error propagation method, (3) learns various amounts representing reactor core performances determined using the physical models as teacher signals, (4) determines the joined load value ω decreased as '0' when it is to less than a predetermined value upon learning described above, and (5) eliminates elements of the nerve circuit net having all of the joined load value decreased to 0. As a result, the neural net model comprises an autonomously simplifying means. (I.S.)

  16. SCORPIO - WWER core surveillance system

    International Nuclear Information System (INIS)

    Hornaes, Arne; Bodal, Terje; Sunde, Svein; Zalesky, K.; Lehman, M.; Pecka, M.; Svarny, J.; Krysl, V.; Juzova, Z.; Sedlak, A.; Semmler, M.

    1998-01-01

    The Institut for energiteknikk has developed the core surveillance system SCORPIO, which has two parallel modes of operation: the Core Follow Mode and the Predictive Mode. The main motivation behind the development of SCORPIO is to make a practical tool for reactor operators which can increase the quality and quantity of information presented on core status and dynamic behavior. This can first of all improve plant safety, as undesired core conditions are detected and prevented. Secondly, more flexible and efficient plant operation is made possible. The system has been implemented on western PWRs, but the basic concept is applicable to a wide range of reactors including WWERs. The main differences between WWERs and typical western PWRs with respect to core surveillance requirements are outlined. The development of a WWER version of SCORPIO has been done in co-operation with the Nuclear Research Institute Rez, and industry partners in the Czech Republic. The first system is installed at Dukovany NPP, where the Site Acceptance Test was completed 6. March 1998.(Authors)

  17. SCORPIO - VVER core surveillance system

    International Nuclear Information System (INIS)

    Hornaes, A.; Bodal, T.; Sunde, S.

    1998-01-01

    The Institutt for energiteknikk has developed the core surveillance system SCORPIO, which has two parallel modes of operation: the Core Follow Mode and the Predictive Mode. The main motivation behind the development of SCORPIO is to make a practical tool for reactor operators, which can increase the quality and quantity of information presented on core status and dynamic behavior. This can first of all improve plant safety, as undesired core conditions are detected and prevented. Secondly, more flexible and efficient plant operation is made possible. The system has been implemented on western PWRs, but the basic concept is applicable to a wide range of reactors including VVERs. The main differences between VVERs and typical western PWRs with respect to core surveillance requirements are outlined. The development of a VVER version of SCORPIO has been done in co-operation with the Nuclear Research Institute Rez, and industry partners in the Czech Republic. The first system is installed at Dukovany NPP, where the Site Acceptance Test was completed 6. March 1998.(author)

  18. Fuel assembly and reactor core

    International Nuclear Information System (INIS)

    Yuchi, Yoko; Aoyama, Motoo; Haikawa, Katsumasa; Yamanaka, Akihiro; Koyama, Jun-ichi.

    1996-01-01

    In a fuel assembly of a BWR type reactor, a region substantially containing burnable poison is divided into an upper region and a lower region having different average concentrations of burnable poison along a transverse cross section perpendicular to the axial direction. The ratio of burnable poison contents of both regions is determined to not more than 80%, and the average concentration of the burnable poison in the lower region is determined to not less than 9% by weight. An infinite multiplication factor at an initial stage of the burning of the fuel assembly is controlled effectively by the burnable poisons. Namely, the ratio of the axial power can be controlled by the distribution of the enrichment degree of uranium fuels and the distribution of the burnable poison concentration in the axial direction. Since the average enrichment degree of the reactor core has to be increased in order to provide an initially loaded reactor core at high burnup degree. Distortion of the power distribution in the axial direction of the reactor core to which fuel assemblies at high enrichment degree are loaded is flattened to improve thermal margin, to extend continuous operation period and increase a burnup degree upon take-out thereby improving fuel economy without worsening the reactor core characteristics of the initially loaded reactor core. (N.H.)

  19. HDAC inhibition induces HIV-1 protein and enables immune-based clearance following latency reversal

    DEFF Research Database (Denmark)

    Wu, Guoxin; Swanson, Michael; Talla, Aarthi

    2017-01-01

    Promising therapeutic approaches for eradicating HIV include transcriptional activation of provirus from latently infected cells using latency-reversing agents (LRAs) and immune-mediated clearance to purge reservoirs. Accurate detection of cells capable of producing viral antigens and virions......, and the measurement of clearance of infected cells, is essential to assessing therapeutic efficacy. Here, we apply enhanced methodology extending the sensitivity limits for the rapid detection of subfemtomolar HIV gag p24 capsid protein in CD4+ T cells from ART-suppressed HIV+ individuals, and we show viral protein...... induction following treatment with LRAs. Importantly, we demonstrate that clinical administration of histone deacetylase inhibitors (HDACis; vorinostat and panobinostat) induced HIV gag p24, and ex vivo stimulation produced sufficient viral antigen to elicit immune-mediated cell killing using anti-gp120/CD3...

  20. Grain alignment in starless cores

    International Nuclear Information System (INIS)

    Jones, T. J.; Bagley, M.; Krejny, M.; Andersson, B.-G.; Bastien, P.

    2015-01-01

    We present near-IR polarimetry data of background stars shining through a selection of starless cores taken in the K band, probing visual extinctions up to A V ∼48. We find that P K /τ K continues to decline with increasing A V with a power law slope of roughly −0.5. Examination of published submillimeter (submm) polarimetry of starless cores suggests that by A V ≳20 the slope for P versus τ becomes ∼−1, indicating no grain alignment at greater optical depths. Combining these two data sets, we find good evidence that, in the absence of a central illuminating source, the dust grains in dense molecular cloud cores with no internal radiation source cease to become aligned with the local magnetic field at optical depths greater than A V ∼20. A simple model relating the alignment efficiency to the optical depth into the cloud reproduces the observations well.

  1. SMART core protection system design

    International Nuclear Information System (INIS)

    Lee, J. K.; Park, H. Y.; Koo, I. S.; Park, H. S.; Kim, J. S.; Son, C. H.

    2003-01-01

    SMART COre Protection System(SCOPS) is designed with real-tims Digital Signal Processor(DSP) board and Network Interface Card(NIC) board. SCOPS has a Control Rod POSition (CRPOS) software module while Core Protection Calculator System(CPCS) consists of Core Protection Calculators(CPCs) and Control Element Assembly(CEA) Calculators(CEACs) in the commercial nuclear plant. It's not necessary to have a independent cabinets for SCOPS because SCOPS is physically very small. Then SCOPS is designed to share the cabinets with Plant Protection System(PPS) of SMART. Therefor it's very easy to maintain the system because CRPOS module is used instead of the computer with operating system

  2. Core-meltdown experimental review

    International Nuclear Information System (INIS)

    1975-08-01

    The results of a study of the experimental evidence having a bearing on hypothetical core meltdowns in light-water reactors are presented. The first objective of the study was to obtain a compendium of the experimental evidence applicable to the analysis of a hypothetical core meltdown. Literature from the nuclear power field and from other scientific disciplines and industrial sources was reviewed. Investigators and other persons knowledgeable in the subject were interviewed. A second objective was to determine what data are required and to determine the adequacy of existing data. In core-meltdown studies only land-based plants have been examined. A third, and final, task of this study was to examine offshore plants to determine applicability of onshore plant analysis to particular areas therein and to determine what information peculiar to meltdown accidents in offshore plants was needed. (U.S.)

  3. Full MOX core for PWRs

    International Nuclear Information System (INIS)

    Puill, A.; Aniel-Buchheit, S.

    1997-01-01

    Plutonium management is a major problem of the back end of the fuel cycle. Fabrication costs must be reduced and plant operation simplified. The design of a full MOX PWR core would enable the number of reactors devoted to plutonium recycling to be reduced and fuel zoning to be eliminated. This paper is a contribution to the feasibility studies for achieving such a core without fundamental modification of the current design. In view of the differences observed between uranium and plutonium characteristics it seems necessary to reconsider the safety of a MOX-fuelled PWR. Reduction of the control worth and modification of the moderator density coefficient are the main consequences of using MOX fuel in a PWR. The core reactivity change during a draining or a cooling is thus of prime interest. The study of core global draining leads to the following conclusion: only plutonium fuels of very poor quality (i.e. with low fissile content) cannot be used in a 900 MWe PWR because of a positive global voiding reactivity effect. During a cooling accident, like an spurious opening of a secondary-side valve, the hypothetical return to criticality of a 100% MOX core controlled by means of 57 control rod clusters (made of hafnium-clad B 4 C rods with a 90% 10 B content) depends on the isotopic plutonium composition. But safety criteria can be complied with for all isotopic compositions provided the 10 B content of the soluble boron is increased to a value of 40%. Core global draining and cooling accidents do not present any major obstacle to the feasibility of a 100% MOX PWR, only minor hardware modifications will be required. (author)

  4. Identifying ELIXIR Core Data Resources.

    Science.gov (United States)

    Durinx, Christine; McEntyre, Jo; Appel, Ron; Apweiler, Rolf; Barlow, Mary; Blomberg, Niklas; Cook, Chuck; Gasteiger, Elisabeth; Kim, Jee-Hyub; Lopez, Rodrigo; Redaschi, Nicole; Stockinger, Heinz; Teixeira, Daniel; Valencia, Alfonso

    2016-01-01

    The core mission of ELIXIR is to build a stable and sustainable infrastructure for biological information across Europe. At the heart of this are the data resources, tools and services that ELIXIR offers to the life-sciences community, providing stable and sustainable access to biological data. ELIXIR aims to ensure that these resources are available long-term and that the life-cycles of these resources are managed such that they support the scientific needs of the life-sciences, including biological research. ELIXIR Core Data Resources are defined as a set of European data resources that are of fundamental importance to the wider life-science community and the long-term preservation of biological data. They are complete collections of generic value to life-science, are considered an authority in their field with respect to one or more characteristics, and show high levels of scientific quality and service. Thus, ELIXIR Core Data Resources are of wide applicability and usage. This paper describes the structures, governance and processes that support the identification and evaluation of ELIXIR Core Data Resources. It identifies key indicators which reflect the essence of the definition of an ELIXIR Core Data Resource and support the promotion of excellence in resource development and operation. It describes the specific indicators in more detail and explains their application within ELIXIR's sustainability strategy and science policy actions, and in capacity building, life-cycle management and technical actions. The identification process is currently being implemented and tested for the first time. The findings and outcome will be evaluated by the ELIXIR Scientific Advisory Board in March 2017. Establishing the portfolio of ELIXIR Core Data Resources and ELIXIR Services is a key priority for ELIXIR and publicly marks the transition towards a cohesive infrastructure.

  5. Reactor core and initially loaded reactor core of nuclear reactor

    International Nuclear Information System (INIS)

    Koyama, Jun-ichi; Aoyama, Motoo.

    1989-01-01

    In BWR type reactors, improvement for the reactor shutdown margin is an important characteristic condition togehter with power distribution flattening . However, in the reactor core at high burnup degree, the reactor shutdown margin is different depending on the radial position of the reactor core. That is , the reactor shutdown margin is smaller in the outer peripheral region than in the central region of the reactor core. In view of the above, the reactor core is divided radially into a central region and as outer region. The amount of fissionable material of first fuel assemblies newly loaded in the outer region is made less than the amount of the fissionable material of second fuel assemblies newly loaded in the central region, to thereby improve the reactor shutdown margin in the outer region. Further, the ratio between the amount of the fissionable material in the upper region and that of the fissionable material in the lower portion of the first fuel assemblies is made smaller than the ratio between the amount of the fissionable material in the upper region and that of the fissionable material in the lower region of the second fuel assemblies, to thereby obtain a sufficient thermal margin in the central region. (K.M.)

  6. Core-to-core dimers forming switchable mesophase

    Czech Academy of Sciences Publication Activity Database

    Horčic, M.; Svoboda, J.; Novotná, Vladimíra; Pociecha, D.; Gorecka, E.

    2017-01-01

    Roč. 53, č. 18 (2017), s. 2721-2724 ISSN 1359-7345 R&D Projects: GA ČR GA15-02843S Institutional support: RVO:68378271 Keywords : liquid crystals * bent- core mesogens * dimers Subject RIV: JJ - Other Materials OBOR OECD: Nano-materials (production and properties) Impact factor: 6.319, year: 2016

  7. Structural characterization of core-bradavidin in complex with biotin

    Science.gov (United States)

    Agrawal, Nitin; Määttä, Juha A. E.; Kulomaa, Markku S.; Hytönen, Vesa P.; Johnson, Mark S.; Airenne, Tomi T.

    2017-01-01

    Bradavidin is a tetrameric biotin-binding protein similar to chicken avidin and bacterial streptavidin, and was originally cloned from the nitrogen-fixing bacteria Bradyrhizobium diazoefficiens. We have previously reported the crystal structure of the full-length, wild-type (wt) bradavidin with 138 amino acids, where the C-terminal residues Gly129-Lys138 (“Brad-tag”) act as an intrinsic ligand (i.e. Gly129-Lys138 bind into the biotin-binding site of an adjacent subunit within the same tetramer) and has potential as an affinity tag for biotechnological purposes. Here, the X-ray structure of core-bradavidin lacking the C-terminal residues Gly114-Lys138, and hence missing the Brad-tag, was crystallized in complex with biotin at 1.60 Å resolution [PDB:4BBO]. We also report a homology model of rhodavidin, an avidin-like protein from Rhodopseudomonas palustris, and of an avidin-like protein from Bradyrhizobium sp. Ai1a-2, both of which have the Brad-tag sequence at their C-terminus. Moreover, core-bradavidin V1, an engineered variant of the original core-bradavidin, was also expressed at high levels in E. coli, as well as a double mutant (Cys39Ala and Cys69Ala) of core-bradavidin (CC mutant). Our data help us to further engineer the core-bradavidin–Brad-tag pair for biotechnological assays and chemical biology applications, and provide deeper insight into the biotin-binding mode of bradavidin. PMID:28426764

  8. Structural characterization of core-bradavidin in complex with biotin.

    Directory of Open Access Journals (Sweden)

    Nitin Agrawal

    Full Text Available Bradavidin is a tetrameric biotin-binding protein similar to chicken avidin and bacterial streptavidin, and was originally cloned from the nitrogen-fixing bacteria Bradyrhizobium diazoefficiens. We have previously reported the crystal structure of the full-length, wild-type (wt bradavidin with 138 amino acids, where the C-terminal residues Gly129-Lys138 ("Brad-tag" act as an intrinsic ligand (i.e. Gly129-Lys138 bind into the biotin-binding site of an adjacent subunit within the same tetramer and has potential as an affinity tag for biotechnological purposes. Here, the X-ray structure of core-bradavidin lacking the C-terminal residues Gly114-Lys138, and hence missing the Brad-tag, was crystallized in complex with biotin at 1.60 Å resolution [PDB:4BBO]. We also report a homology model of rhodavidin, an avidin-like protein from Rhodopseudomonas palustris, and of an avidin-like protein from Bradyrhizobium sp. Ai1a-2, both of which have the Brad-tag sequence at their C-terminus. Moreover, core-bradavidin V1, an engineered variant of the original core-bradavidin, was also expressed at high levels in E. coli, as well as a double mutant (Cys39Ala and Cys69Ala of core-bradavidin (CC mutant. Our data help us to further engineer the core-bradavidin-Brad-tag pair for biotechnological assays and chemical biology applications, and provide deeper insight into the biotin-binding mode of bradavidin.

  9. CCTF CORE I test results

    International Nuclear Information System (INIS)

    Murao, Yoshio; Sudoh, Takashi; Akimoto, Hajime; Iguchi, Tadashi; Sugimoto, Jun; Fujiki, Kazuo; Hirano, Kenmei

    1982-07-01

    This report presents the results of the following CCTF CORE I tests conducted in FY. 1980. (1) Multi-dimensional effect test, (2) Evaluation model test, (3) FLECHT coupling test. On the first test, one-dimensional treatment of the core thermohydrodynamics was discussed. On the second and third tests, the test results were compared with the results calculated by the evaluation model codes and the results of the corresponding FLECHT-SET test (Run 2714B), respectively. The work was performed under contracts with the Atomic Energy Bureau of Science and Technology Agency of Japan. (author)

  10. Core baffle for nuclear reactors

    International Nuclear Information System (INIS)

    Machado, O.J.; Berringer, R.T.

    1977-01-01

    The invention concerns the design of the core of a LWR with a large number of fuel assemblies formed by fuel rods and kept in position by spacer grids. According to the invention, at the level of the spacer grids match plates are mounted with openings so the flow of coolant directed upwards will not be obstructed and a parallel bypass will be obtained in the space between the core barrel and the baffle plates. In case of an accident, this configuration reduces or avoids damage from overpressure reactions. (HP) [de

  11. Understanding Core-Collapse Supernovae

    Science.gov (United States)

    Hix, W. R.; Lentz, E. J.; Baird, M.; Messer, O. E. B.; Mezzacappa, A.; Lee, C.-T.; Bruenn, S. W.; Blondin, J. M.; Marronetti, P.

    2010-03-01

    Our understanding of core-collapse supernovae continues to improve as better microphysics is included in increasingly realistic neutrino-radiationhydrodynamic simulations. Recent multi-dimensional models with spectral neutrino transport, which slowly develop successful explosions for a range of progenitors between 12 and 25 solar mass, have motivated changes in our understanding of the neutrino reheating mechanism. In a similar fashion, improvements in nuclear physics, most notably explorations of weak interactions on nuclei and the nuclear equation of state, continue to refine our understanding of how supernovae explode. Recent progresses on both the macroscopic and microscopic effects that affect core-collapse supernovae are discussed.

  12. Core seismic methods verification report

    International Nuclear Information System (INIS)

    Olsen, B.E.; Shatoff, H.D.; Rakowski, J.E.; Rickard, N.D.; Thompson, R.W.; Tow, D.; Lee, T.H.

    1979-12-01

    This report presents the description and validation of the analytical methods for calculation of the seismic loads on an HTGR core and the core support structures. Analytical modeling, integration schemes, parameter assignment, parameter sensitivity, and correlation with test data are key topics which have been covered in detail. Much of the text concerns the description and the results of a series of scale model tests performed to obtain data for code correlation. A discussion of scaling laws, model properties, seismic excitation, instrumentation, and data reduction methods is also presented, including a section on the identification and calculation of statistical errors in the test data

  13. Core microbiomes for sustainable agroecosystems.

    Science.gov (United States)

    Toju, Hirokazu; Peay, Kabir G; Yamamichi, Masato; Narisawa, Kazuhiko; Hiruma, Kei; Naito, Ken; Fukuda, Shinji; Ushio, Masayuki; Nakaoka, Shinji; Onoda, Yusuke; Yoshida, Kentaro; Schlaeppi, Klaus; Bai, Yang; Sugiura, Ryo; Ichihashi, Yasunori; Minamisawa, Kiwamu; Kiers, E Toby

    2018-05-01

    In an era of ecosystem degradation and climate change, maximizing microbial functions in agroecosystems has become a prerequisite for the future of global agriculture. However, managing species-rich communities of plant-associated microbiomes remains a major challenge. Here, we propose interdisciplinary research strategies to optimize microbiome functions in agroecosystems. Informatics now allows us to identify members and characteristics of 'core microbiomes', which may be deployed to organize otherwise uncontrollable dynamics of resident microbiomes. Integration of microfluidics, robotics and machine learning provides novel ways to capitalize on core microbiomes for increasing resource-efficiency and stress-resistance of agroecosystems.

  14. Hepatitis C virus infection protein network.

    Science.gov (United States)

    de Chassey, B; Navratil, V; Tafforeau, L; Hiet, M S; Aublin-Gex, A; Agaugué, S; Meiffren, G; Pradezynski, F; Faria, B F; Chantier, T; Le Breton, M; Pellet, J; Davoust, N; Mangeot, P E; Chaboud, A; Penin, F; Jacob, Y; Vidalain, P O; Vidal, M; André, P; Rabourdin-Combe, C; Lotteau, V

    2008-01-01

    A proteome-wide mapping of interactions between hepatitis C virus (HCV) and human proteins was performed to provide a comprehensive view of the cellular infection. A total of 314 protein-protein interactions between HCV and human proteins was identified by yeast two-hybrid and 170 by literature mining. Integration of this data set into a reconstructed human interactome showed that cellular proteins interacting with HCV are enriched in highly central and interconnected proteins. A global analysis on the basis of functional annotation highlighted the enrichment of cellular pathways targeted by HCV. A network of proteins associated with frequent clinical disorders of chronically infected patients was constructed by connecting the insulin, Jak/STAT and TGFbeta pathways with cellular proteins targeted by HCV. CORE protein appeared as a major perturbator of this network. Focal adhesion was identified as a new function affected by HCV, mainly by NS3 and NS5A proteins.

  15. Advanced core monitoring technology for WWER reactors

    International Nuclear Information System (INIS)

    Nguyen, T.Q.; Casadei, A.L.; Doshi, P.K.

    1993-01-01

    The Westinghouse BEACON online monitoring system has been developed to provide continuous core monitoring and operational support for pressurized water reactor using movable detectors (fission chamber) and core thermocouples. The basic BEACON core monitoring methodology is described. Traditional WWER reactors use rhodium fixed in-core detectors as the means to provide detailed core power distribution for surveillance purposes. An adapted version of the BEACON advanced core monitoring and support system is described which seems to be, due to the different demand/response requirements, the optimal solution (for routine surveillance and anomaly detection) for WWER reactors with existing fixed in-core detectors. (Z.S.) 4 refs

  16. Antibodies to the HIV-1 Tat protein correlated with nonprogression to AIDS: a rationale for the use of Tat toxoid as an HIV-1 vaccine.

    Science.gov (United States)

    Zagury, J F; Sill, A; Blattner, W; Lachgar, A; Le Buanec, H; Richardson, M; Rappaport, J; Hendel, H; Bizzini, B; Gringeri, A; Carcagno, M; Criscuolo, M; Burny, A; Gallo, R C; Zagury, D

    1998-01-01

    To investigate which immune parameters, such as antibodies against HIV-1 specificities, or viral parameters, such as p24 antigenemia, are predictive of disease progression. We performed studies on serum collected from individuals exhibiting two extremes of disease evolution--67 fast progressors (FP) and 182 nonprogressors (NP)--at their enrollment. After a 1- to 2-year clinical follow-up of 104 nonprogressors after their enrollment, we could determine the best serologic predictors for disease progression. We investigated levels of antibodies to tetanus toxoid and to HIV antigens including Env, Gag, Nef, and Tat proteins, as well as p24 antigenemia, viremia, CD4 cell count, and interferon-alpha (IFN-alpha) titers in FPs and NPs, and we correlated these data with clinical and biologic signs of progression. p24 Antigenemia, a marker of viral replication, and anti-Tat antibodies were highly and inversely correlated in both groups (P < .001). Furthermore, anti-p24 antibodies and low serum IFN-alpha levels were correlated to the NP versus the FP cohort. Finally, among NPs, only antibodies to Tat and not to the other HIV specificities (Env, Nef, Gag) were significantly predictive of clinical stability during their follow-up. Antibodies toward HIV-1 Tat, which are inversely correlated to p24 antigenemia, appear as a critical marker for a lack of disease progression. This study strongly suggests that rising anti-Tat antibodies through active immunization may be beneficial in AIDS vaccine development to control viral replication.

  17. Reactor core operation management system

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Tomomi.

    1992-05-28

    Among operations of periodical inspection for a nuclear power plant, sequence, time and safety rule, as well as necessary equipments and the number thereof required for each of the operation are determined previously for given operation plannings, relevant to the reactor core operations. Operation items relative to each of coordinates of the reactor core are retrieved and arranged based on specified conditions, to use the operation equipments effectively. Further, a combination of operations, relative to the reactor core coordinates with no physical interference and shortest in accordance with safety rules is judged, and the order and the step of the operation relevant to the entire reactor core operations are planned. After the start of the operation, the necessity for changing the operation sequence is judged depending on the judgement as to whether it is conducted according to the safety rule and the deviation between the plan and the result, based on the information for the progress of each of the operations. Alternatively, the operation sequence and the step to be changed are planned again in accordance with the requirement for the change of the operation planning. Then, the shortest operation time can be planned depending on the simultaneous operation impossible condition and the condition for the operation time zone determined by labor conditions. (N.H.).

  18. Competition for cores in remanufacturing

    NARCIS (Netherlands)

    Bulmus, Serra Caner; Zhu, Stuart X.; Teunter, Ruud

    2014-01-01

    We study competition between an original equipment manufacturer (OEM) and an independently operating remanufacturer (IO). Different from the existing literature, the OEM and IO compete not only for selling their products but also for collecting returned products (cores) through their acquisition

  19. Studies on WWER core diagnostics

    International Nuclear Information System (INIS)

    Lunin, G.L.; Mitin, V.I.; Bulavin, V.V.

    1987-01-01

    The reliability and safety of nuclear power plants have decisive meaning under the situation that nuclear power generation steadily increases, and among various measures aiming at ensuring the reliability and safety in the operation of nuclear power plants, the countermeasures for protecting reactor core, main process equipment and high pressure circuits from damage have the important role, and the monitoring of condition and the organization of forecast, which are carried out continuously or periodically during the operation of nuclear power stations using the diagnostic expert system specially developed for the purpose, are included in them. Such monitoring enables the early detection of mechanical damage, increase of vibration, defects caused during operation and so on in reactor cores and primary and secondary circuits, and the continuous watching of defect developments. Also boiling in a core is detected, the place of abnormality occurrence is identified, and the intensity and characteristics of boiling are determined, thus the occurrence of dangerous condition is prevented. The developments of an in-core monitoring system and noise diagnostic systems are reported. (Kako, I.)

  20. Modeling of the reactor core

    International Nuclear Information System (INIS)

    1999-01-01

    In order to improve technical - economical parameters fuel with 2.4% enrichment and burnable absorber is started to be used at Ignalina NPP. Using code QUABOX/CUBBOX the main neutronic - physical characteristics were calculated for selected reactor core conditions

  1. Core calculational techniques and procedures

    International Nuclear Information System (INIS)

    Romano, J.J.

    1977-10-01

    Described are the procedures and techniques employed by B and W in core design analyses of power peaking, control rod worths, and reactivity coefficients. Major emphasis has been placed on current calculational tools and the most frequently performed calculations over the operating power range

  2. Water-core Fresnel fiber

    NARCIS (Netherlands)

    Martelli, C.; Canning, J.; Lyytikainen, K.; Groothoff, N.

    2005-01-01

    A water core photonic crystal Fresnel fiber exploiting a hole distribution on zone plates of a cylindrical waveguide was developed and characterized. This fiber has similar guiding properties as the pristine air-hole guiding fiber although a large loss edge ~900nm is observed indicating that the

  3. Core shift effect in blazars

    Science.gov (United States)

    Agarwal, A.; Mohan, P.; Gupta, Alok C.; Mangalam, A.; Volvach, A. E.; Aller, M. F.; Aller, H. D.; Gu, M. F.; Lähteenmäki, A.; Tornikoski, M.; Volvach, L. N.

    2017-07-01

    We studied the pc-scale core shift effect using radio light curves for three blazars, S5 0716+714, 3C 279 and BL Lacertae, which were monitored at five frequencies (ν) between 4.8 and 36.8 GHz using the University of Michigan Radio Astronomical Observatory (UMRAO), the Crimean Astrophysical Observatory (CrAO) and Metsähovi Radio Observatory for over 40 yr. Flares were Gaussian fitted to derive time delays between observed frequencies for each flare (Δt), peak amplitude (A) and their half width. Using A ∝ να, we infer α in the range of -16.67-2.41 and using Δ t ∝ ν ^{1/k_r}, we infer kr ∼ 1, employed in the context of equipartition between magnetic and kinetic energy density for parameter estimation. From the estimated core position offset (Ωrν) and the core radius (rcore), we infer that opacity model may not be valid in all cases. The mean magnetic field strengths at 1 pc (B1) and at the core (Bcore) are in agreement with previous estimates. We apply the magnetically arrested disc model to estimate black hole spins in the range of 0.15-0.9 for these blazars, indicating that the model is consistent with expected accretion mode in such sources. The power-law-shaped power spectral density has slopes -1.3 to -2.3 and is interpreted in terms of multiple shocks or magnetic instabilities.

  4. Reactor core operation management system

    International Nuclear Information System (INIS)

    Sato, Tomomi.

    1992-01-01

    Among operations of periodical inspection for a nuclear power plant, sequence, time and safety rule, as well as necessary equipments and the number thereof required for each of the operation are determined previously for given operation plannings, relevant to the reactor core operations. Operation items relative to each of coordinates of the reactor core are retrieved and arranged based on specified conditions, to use the operation equipments effectively. Further, a combination of operations, relative to the reactor core coordinates with no physical interference and shortest in accordance with safety rules is judged, and the order and the step of the operation relevant to the entire reactor core operations are planned. After the start of the operation, the necessity for changing the operation sequence is judged depending on the judgement as to whether it is conducted according to the safety rule and the deviation between the plan and the result, based on the information for the progress of each of the operations. Alternatively, the operation sequence and the step to be changed are planned again in accordance with the requirement for the change of the operation planning. Then, the shortest operation time can be planned depending on the simultaneous operation impossible condition and the condition for the operation time zone determined by labor conditions. (N.H.)

  5. Stellar core collapse and supernova

    International Nuclear Information System (INIS)

    Wilson, J.R.; Mayle, R.; Woosley, S.E.; Weaver, T.

    1985-04-01

    Massive stars that end their stable evolution as their iron cores collapse to a neutron star or black hole long been considered good candidates for producing Type II supernovae. For many years the outward propagation of the shock wave produced by the bounce of these iron cores has been studied as a possible mechanism for the explosion. For the most part, the results of these studies have not been particularly encouraging, except, perhaps, in the case of very low mass iron cores or very soft nuclear equations of state. The shock stalls, overwhelmed by photodisintegration and neutrino losses, and the star does not explode. More recently, slow late time heating of the envelope of the incipient neutron star has been found to be capable of rejuvenating the stalled shock and producing an explosion after all. The present paper discusses this late time heating and presents results from numerical calculations of the evolution, core collapse, and subsequent explosion of a number of recent stellar models. For the first time they all, except perhaps the most massive, explode with reasonable choices of input physics. 39 refs., 17 figs., 1 tab

  6. Nuclear reactor core servicing apparatus

    International Nuclear Information System (INIS)

    Andrea, C.

    1977-01-01

    Disclosed is an improved core servicing apparatus for a nuclear reactor of the type having a reactor vessel, a vessel head having a head penetration therethrough, a removable plug adapted to fit in the head penetration, and a core of the type having an array of elongated assemblies. The improved core servicing apparatus comprises a plurality of support columns suspended from the removable plug and extending downward toward the nuclear core, rigid support means carried by each of the support columns, and a plurality of servicing means for each of the support columns for servicing a plurality of assemblies. Each of the plurality of servicing means for each of the support columns is fixedly supported in a fixed array from the rigid support means. Means are provided for rotating the rigid support means and servicing means between condensed and expanded positions. When in the condensed position, the rigid support means and servicing means lie completely within the coextensive boundaries of the plug, and when in the expanded position, some of the rigid support means and servicing means lie without the coextensive boundaries of the plug

  7. One Health Core Competency Domains

    Directory of Open Access Journals (Sweden)

    Rebekah Frankson

    2016-09-01

    Full Text Available The emergence of complex global challenges at the convergence of human, animal, and environmental health has catalyzed a movement supporting ‘One Health’ approaches. Despite recognition of the importance of One Health approaches to address these complex challenges, little effort has been directed at identifying the seminal knowledge, skills and attitudes necessary for individuals to successfully contribute to One Health efforts. Between 2008 and 2011, three groups independently embarked on separate initiatives to identify core competencies for professionals involved with One Health approaches. Core competencies were considered critically important for guiding curriculum development and continuing professional education as they describe the knowledge, skills and attitudes required to be effective. A workshop was convened in 2012 to synthesize the various strands of work on One Health competencies. Despite having different mandates, participants, and approaches, all of these initiatives identified similar core competency domains: management; communication and informatics; values and ethics; leadership; teams and collaboration; roles and responsibilities; and systems thinking. These core competency domains have been used to develop new continuing professional education programs for One Health professionals and help university curricula prepare new graduates to be able to contribute more effectively to One Health approaches.

  8. One Health Core Competency Domains.

    Science.gov (United States)

    Frankson, Rebekah; Hueston, William; Christian, Kira; Olson, Debra; Lee, Mary; Valeri, Linda; Hyatt, Raymond; Annelli, Joseph; Rubin, Carol

    2016-01-01

    The emergence of complex global challenges at the convergence of human, animal, and environmental health has catalyzed a movement supporting "One Health" approaches. Despite recognition of the importance of One Health approaches to address these complex challenges, little effort has been directed at identifying the seminal knowledge, skills, and attitudes necessary for individuals to successfully contribute to One Health efforts. Between 2008 and 2011, three groups independently embarked on separate initiatives to identify core competencies for professionals involved with One Health approaches. Core competencies were considered critically important for guiding curriculum development and continuing professional education, as they describe the knowledge, skills, and attitudes required to be effective. A workshop was convened in 2012 to synthesize the various strands of work on One Health competencies. Despite having different mandates, participants, and approaches, all of these initiatives identified similar core competency domains: management; communication and informatics; values and ethics; leadership; teams and collaboration; roles and responsibilities; and systems thinking. These core competency domains have been used to develop new continuing professional education programs for One Health professionals and help university curricula prepare new graduates to be able to contribute more effectively to One Health approaches.

  9. Neutronics calculation of RTP core

    Science.gov (United States)

    Rabir, Mohamad Hairie B.; Zin, Muhammad Rawi B. Mohamed; Karim, Julia Bt. Abdul; Bayar, Abi Muttaqin B. Jalal; Usang, Mark Dennis Anak; Mustafa, Muhammad Khairul Ariff B.; Hamzah, Na'im Syauqi B.; Said, Norfarizan Bt. Mohd; Jalil, Muhammad Husamuddin B.

    2017-01-01

    Reactor calculation and simulation are significantly important to ensure safety and better utilization of a research reactor. The Malaysian's PUSPATI TRIGA Reactor (RTP) achieved initial criticality on June 28, 1982. The reactor is designed to effectively implement the various fields of basic nuclear research, manpower training, and production of radioisotopes. Since early 90s, neutronics modelling were used as part of its routine in-core fuel management activities. The are several computer codes have been used in RTP since then, based on 1D neutron diffusion, 2D neutron diffusion and 3D Monte Carlo neutron transport method. This paper describes current progress and overview on neutronics modelling development in RTP. Several important parameters were analysed such as keff, reactivity, neutron flux, power distribution and fission product build-up for the latest core configuration. The developed core neutronics model was validated by means of comparison with experimental and measurement data. Along with the RTP core model, the calculation procedure also developed to establish better prediction capability of RTP's behaviour.

  10. In Search of Functional Advantages of Knots in Proteins.

    OpenAIRE

    Dabrowski-Tumanski, P.; Stasiak, A.; Sulkowska, J.I.

    2016-01-01

    We analysed the structure of deeply knotted proteins representing three unrelated families of knotted proteins. We looked at the correlation between positions of knotted cores in these proteins and such local structural characteristics as the number of intra-chain contacts, structural stability and solvent accessibility. We observed that the knotted cores and especially their borders showed strong enrichment in the number of contacts. These regions showed also increased thermal stability, whe...

  11. Protein Adsorption in Three Dimensions

    Science.gov (United States)

    Vogler, Erwin A.

    2011-01-01

    Recent experimental and theoretical work clarifying the physical chemistry of blood-protein adsorption from aqueous-buffer solution to various kinds of surfaces is reviewed and interpreted within the context of biomaterial applications, especially toward development of cardiovascular biomaterials. The importance of this subject in biomaterials surface science is emphasized by reducing the “protein-adsorption problem” to three core questions that require quantitative answer. An overview of the protein-adsorption literature identifies some of the sources of inconsistency among many investigators participating in more than five decades of focused research. A tutorial on the fundamental biophysical chemistry of protein adsorption sets the stage for a detailed discussion of the kinetics and thermodynamics of protein adsorption, including adsorption competition between two proteins for the same adsorbent immersed in a binary-protein mixture. Both kinetics and steady-state adsorption can be rationalized using a single interpretive paradigm asserting that protein molecules partition from solution into a three-dimensional (3D) interphase separating bulk solution from the physical-adsorbent surface. Adsorbed protein collects in one-or-more adsorbed layers, depending on protein size, solution concentration, and adsorbent surface energy (water wettability). The adsorption process begins with the hydration of an adsorbent surface brought into contact with an aqueous-protein solution. Surface hydration reactions instantaneously form a thin, pseudo-2D interface between the adsorbent and protein solution. Protein molecules rapidly diffuse into this newly-formed interface, creating a truly 3D interphase that inflates with arriving proteins and fills to capacity within milliseconds at mg/mL bulk-solution concentrations CB. This inflated interphase subsequently undergoes time-dependent (minutes-to-hours) decrease in volume VI by expulsion of either-or-both interphase water and

  12. The core to regulatory reform

    International Nuclear Information System (INIS)

    Partridge, J.W. Jr.

    1993-01-01

    Federal Energy Regulatory Commission (FERC) Orders 436, 500, and 636, the Clean Air Act Amendments of 1990, Public Utility Holding Company Act reform, and the 1992 Energy Policy Act all can have significant effects on an LDC's operations. Such changes in an LDC's environments must be balanced by changes within the utility, its marketplace, and its state regulatory environment. The question is where to start. For Columbia Gas Distribution Cos., based in Columbus, OH, the new operating foundation begins with each employee. Internal strength is critical in designing initiatives that meet the needs of the marketplace and are well-received by regulators. Employees must understand not only the regulatory environment in which the LDC operates, but also how their work contributes to a positive regulatory relationship. To achieve this, Columbia initiated the COntinuing Regulatory Education program, or CORE, in 1991. CORE is a regulatory-focused, information-initiative program coordinated by Columbia's Regulatory Policy, Planning, and Government Affairs Department. The CORE programs can take many forms, such as emerging issue discussions, dialogues with regulators and key parties, updates on regulatory fillings, regulatory policy meetings, and formal training classes. The speakers and discussion facilitators can range from human resource department trainers to senior officers, from regulatory department staff members to external experts, or from state commissioners to executives from other LDCs. The goals of CORE initiatives are to: Support a professional level of regulatory expertise through employee participation in well-developed regulatory programs presented by credible experts. Encourage a constructive state regulatory environment founded on communication and cooperation. CORE achieves these goals via five program levels: introductory basics, advanced learning, professional expertise, crossfunctional dialogues, and external idea exchanges

  13. CORE

    DEFF Research Database (Denmark)

    Krigslund, Jeppe; Hansen, Jonas; Hundebøll, Martin

    2013-01-01

    State-of-the-art in network coding for wireless, meshed networks typically considers two problems separately. First, the problem of providing reliability for a single session. Second, the problem of opportunistic combination of flows by using minimalistic coding, i.e., by XORing packets from diff...

  14. Conceptual core model for the reactor core test

    International Nuclear Information System (INIS)

    Swenson, L.D.

    1970-01-01

    Several design options for the ZrH Flight System Reactor were investigated which involved tradeoffs of core excess reactivity, reactor control, coolant mixing and cladding thickness. A design point was selected which is to be the basis for more detailed evaluation in the preliminary design phase. The selected design utilizes 295 elements with 0.670 inch element-to-element pitch, 32 mil thick Incoloy cladding, 18.00 inches long fuel meat, hydrogen content of 6.3 x 10 22 atoms/cc fuel, 10.5 w/o uranium, and a spiraled fin configuration with alternate elements having fins with spiral to the right, spiral to the left, and no fin at all (R-L-N fin configuration). Fin height is 30 mils for the center region of the core and 15 mils for the outer region. (U.S.)

  15. Core mechanics and configuration behavior of advanced LMFBR core restraint concepts

    International Nuclear Information System (INIS)

    Fox, J.N.; Wei, B.C.

    1978-02-01

    Core restraint systems in LMFBRs maintain control of core mechanics and configuration behavior. Core restraint design is complex due to the close spacing between adjacent components, flux and temperature gradients, and irradiation-induced material property effects. Since the core assemblies interact with each other and transmit loads directly to the core restraint structural members, the core assemblies themselves are an integral part of the core restraint system. This paper presents an assessment of several advanced core restraint system and core assembly concepts relative to the expected performance of currently accepted designs. A recommended order for the development of the advanced concepts is also presented

  16. Cores to the rescue: how old cores enable new science

    Science.gov (United States)

    Ito, E.; Noren, A. J.; Brady, K.

    2016-12-01

    The value of archiving scientific specimens and collections for the purpose of enabling further research using new analytical techniques, resolving conflicting results, or repurposing them for entirely new research, is often discussed in abstract terms. We all agree that samples with adequate metadata ought to be archived systematically for easy access, for a long time and stored under optimal conditions. And yet, as storage space fills, there is a temptation to cull the collection, or when a researcher retires, to discard the collection unless the researcher manages to make his or her own arrangement for the collection to be accessioned elsewhere. Nobody has done anything with these samples in over 20 years! Who would want them? It turns out that plenty of us do want them, if we know how to find them and if they have sufficient metadata to assess past work and suitability for new analyses. The LacCore collection holds over 33 km of core from >6700 sites in diverse geographic locations worldwide with samples collected as early as 1950s. From these materials, there are many examples to illustrate the scientific value of archiving geologic samples. One example that benefitted Ito personally were cores from Lakes Mirabad and Zeribar, Iran, acquired in 1963 by Herb Wright and his associates. Several doctoral and postdoctoral students generated and published paleoecological reconstructions based on cladocerans, diatoms, pollen or plant macrofossils, mostly between 1963 and 1967. The cores were resampled in 1990s by a student being jointly advised by Wright and Ito for oxygen isotope analysis of endogenic calcite. The results were profitably compared with pollen and the results published in 2001 and 2006. From 1979 until very recently, visiting Iran for fieldwork was not pallowed for US scientists. Other examples will be given to further illustrate the power of archived samples to advance science.

  17. Separated core turbofan engine; Core bunrigata turbofan engine

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Y; Endo, M; Matsuda, Y; Sugiyama, N; Sugahara, N; Yamamoto, K [National Aerospace Laboratory, Tokyo (Japan)

    1996-04-01

    This report outlines the separated core turbofan engine. This engine is featured by parallel separated arrangement of a fan and core engine which are integrated into one unit in the conventional turbofan engine. In general, cruising efficiency improvement and noise reduction are achieved by low fan pressure ratio and low exhaust speed due to high bypass ratio, however, it causes various problems such as large fan and nacelle weight due to large air flow rate of a fan, and shift of an operating point affected by flight speed. The parallel separated arrangement is thus adopted. The stable operation of a fan and core engine is easily retained by independently operating air inlet unaffected by fan. The large degree of freedom of combustion control is also obtained by independent combustor. Fast response, simple structure and optimum aerodynamic design are easily achieved. This arrangement is also featured by flexibility of development and easy maintenance, and by various merits superior to conventional turbofan engines. It has no technological problems difficult to be overcome, and is also suitable for high-speed VTOL transport aircraft. 4 refs., 5 figs.

  18. Reactor core in FBR type reactor

    International Nuclear Information System (INIS)

    Masumi, Ryoji; Kawashima, Katsuyuki; Kurihara, Kunitoshi.

    1989-01-01

    In a reactor core in FBR type reactors, a portion of homogenous fuels constituting the homogenous reactor core is replaced with multi-region fuels in which the enrichment degree of fissile materials is lower nearer to the axial center. This enables to condition the composition such that a reactor core having neutron flux distribution either of a homogenous reactor core or a heterogenous reactor core has substantially identical reactivity. Accordingly, in the transfer from the homogenous reactor core to the axially heterogenous reactor core, the average reactivity in the reactor core is substantially equal in each of the cycles. Further, by replacing a portion of the homogenous fuels with a multi-region fuels, thereby increasing the heat generation near the axial center, it is possiable to reduce the linear power output in the regions above and below thereof and, in addition, to improve the thermal margin in the reactor core. (T.M.)

  19. Espaço de cores

    Directory of Open Access Journals (Sweden)

    Claudia Feitosa-Santana

    2006-01-01

    Full Text Available O artigo apresenta definições para os termos espaço de cores e sistemas de cores; classifica, de acordo com David Brainard (2003, os sistemas de cores em dois grupos: aparência de cores e diferenças de cores. Dentre os diversos sistemas de cores existentes, o artigo descreve dois deles: o sistema de cores Munsell &– um dos mais utilizados entre os sistemas de aparência de cores &– e a descrição do sistema de cores CIE 1931 &– um dos mais utilizados dentre os sistemas de diferença de cores. Faz-se uma retrospectiva histórica da busca por espaços de cores que representem a percepção de cores humana assim como as diversas reconstruções de espaços de cores por métodos eletrofisiológicos ou psicofísicos. Muitas dessas reconstruções utilizam a escala multidimensional (mds. O artigo também introduz a possibilidade da reconstrução dos espaços de cores de pacientes com discromatopsia adquirida como uma distorção do espaço de indivíduos tricromatas normais.

  20. Conceptual study of advanced PWR core design

    International Nuclear Information System (INIS)

    Kim, Young Jin; Chang, Moon Hee; Kim, Keung Ku; Joo, Hyung Kuk; Kim, Young Il; Noh, Jae Man; Hwang, Dae Hyun; Kim, Taek Kyum; Yoo, Yon Jong.

    1997-09-01

    The purpose of this project is for developing and verifying the core design concepts with enhanced safety and economy, and associated methodologies for core analyses. From the study of the sate-of-art of foreign advanced reactor cores, we developed core concepts such as soluble boron free, high convertible and enhanced safety core loaded semi-tight lattice hexagonal fuel assemblies. To analyze this hexagonal core, we have developed and verified some neutronic and T/H analysis methodologies. HELIOS code was adopted as the assembly code and HEXFEM code was developed for hexagonal core analysis. Based on experimental data in hexagonal lattices and the COBRA-IV-I code, we developed a thermal-hydraulic analysis code for hexagonal lattices. Using the core analysis code systems developed in this project, we designed a 600 MWe core and studied the feasibility of the core concepts. Two additional scopes were performed in this project : study on the operational strategies of soluble boron free core and conceptual design of large scale passive core. By using the axial BP zoning concept and suitable design of control rods, this project showed that it was possible to design a soluble boron free core in 600 MWe PWR. The results of large scale core design showed that passive concepts and daily load follow operation could be practiced. (author). 15 refs., 52 tabs., 101 figs

  1. Conceptual study of advanced PWR core design

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Jin; Chang, Moon Hee; Kim, Keung Ku; Joo, Hyung Kuk; Kim, Young Il; Noh, Jae Man; Hwang, Dae Hyun; Kim, Taek Kyum; Yoo, Yon Jong

    1997-09-01

    The purpose of this project is for developing and verifying the core design concepts with enhanced safety and economy, and associated methodologies for core analyses. From the study of the sate-of-art of foreign advanced reactor cores, we developed core concepts such as soluble boron free, high convertible and enhanced safety core loaded semi-tight lattice hexagonal fuel assemblies. To analyze this hexagonal core, we have developed and verified some neutronic and T/H analysis methodologies. HELIOS code was adopted as the assembly code and HEXFEM code was developed for hexagonal core analysis. Based on experimental data in hexagonal lattices and the COBRA-IV-I code, we developed a thermal-hydraulic analysis code for hexagonal lattices. Using the core analysis code systems developed in this project, we designed a 600 MWe core and studied the feasibility of the core concepts. Two additional scopes were performed in this project : study on the operational strategies of soluble boron free core and conceptual design of large scale passive core. By using the axial BP zoning concept and suitable design of control rods, this project showed that it was possible to design a soluble boron free core in 600 MWe PWR. The results of large scale core design showed that passive concepts and daily load follow operation could be practiced. (author). 15 refs., 52 tabs., 101 figs.

  2. Analysis Of Core Management For The Transition Cores Of RSG-GAS Reactor To Full-Silicide Core

    International Nuclear Information System (INIS)

    Malem Sembiring, Tagor; Suparlina, Lily; Tukiran

    2001-01-01

    The core conversion of RSG-GAS reactor from oxide to silicide core with meat density of 2.96 g U/cc is still doing. At the end of 2000, the reactor has been operated for 3 transition cores which is the mixed core of oxide-silicide. Based on previous work, the calculated core parameter for the cores were obtained and it is needed 10 transition cores to achieve a full-silicide core. The objective of this work is to acquire the effect of the increment of the number of silicide fuel on the core parameters such as excess reactivity and shutdown margin. The measurement of the core parameters was carried out using the method of compensation of couple control rods. The experiment shows that the excess reactivity trends lower with the increment of the number of silicide fuel in the core. However, the shutdown margin is not change with the increment of the number of silicide fuel. Therefore, the transition cores can be operated safety to a full-silicide core

  3. Simulation experiments concerning core meltdown

    International Nuclear Information System (INIS)

    Werle, H.

    1979-01-01

    A gas stream causes a remarkable increase in the interfacial heat flux (by a factor of 8 for v = 0.63 cm/s, v = gas volume flux/horizontal area). The most important characteristics of the system investigated (silicon oil/wood metal) are relatively similar to those of a core melt, Therefore a remarkable increase of the interfacial heat transfer by the gas release may be expected also for a core melt, compared with earlier investigations at the system silicon oil/water the influence of a gas stream is nevertheless remarkably lower for silicon oil/wood metal. This shows that the density ratio plays an important role. (orig./RW) [de

  4. TMI-2 core examination plan

    International Nuclear Information System (INIS)

    Carlson, J.O.

    1984-07-01

    The role of the Three Mile Island Unit 2 (TMI-2) core examination in the resolution of major nuclear safety issues is delineated in this plan. Relevant data needs are discussed, and approaches for recovering data from the TMI-2 plant are identified. Specific recommendations and justifications are provided for in situ documentation and off-site artifact examination activities. The research and development program is being managed by EG and G Idaho, Inc

  5. Lanczos Tridiagonalization and Core Problems

    Czech Academy of Sciences Publication Activity Database

    Hnětynková, Iveta; Strakoš, Zdeněk

    2007-01-01

    Roč. 421, č. 2-3 (2007), s. 243-251 ISSN 0024-3795 R&D Projects: GA AV ČR 1ET400300415 Institutional research plan: CEZ:AV0Z10300504 Keywords : linear approximation problem * orthogonal transformation * core problem * Golub-Kahan bidiagonalization * Lanczos tridiagonalization * Jacobi matrix Subject RIV: BA - General Mathematics Impact factor: 0.702, year: 2007

  6. Core curriculum illustration: rib fractures.

    Science.gov (United States)

    Dunham, Gregor M; Perez-Girbes, Alexandre; Linnau, Ken F

    2017-06-01

    This is the 24th installment of a series that will highlight one case per publication issue from the bank of cases available online as part of the American Society of Emergency Radiology (ASER) educational resources. Our goal is to generate more interest in and use of our online materials. To view more cases online, please visit the ASER Core Curriculum and Recommendations for Study online at http://www.aseronline.org/curriculum/toc.htm .

  7. Core labour standards and exports

    OpenAIRE

    Siroën, Jean-Marc

    2017-01-01

    (english) Core labour standards defined by the ILO in 1998 are universal, but applied very differently across countries. Compliance is much higher in high income countries. However, the causality between improved labour standards and economic growth remains a controversial issue. Export-led growth strategies might encourage developing countries to curb the process of standards improvement. In this way, they can raise the volume of their unskilled labour endowments (child and/or forced labour)...

  8. Nuclear reactor core safety device

    International Nuclear Information System (INIS)

    Colgate, S.A.

    1977-01-01

    The danger of a steam explosion from a nuclear reactor core melt-down can be greatly reduced by adding a gasifying agent to the fuel that releases a large amount of gas at a predetermined pre-melt-down temperature that ruptures the bottom end of the fuel rod and blows the finely divided fuel into a residual coolant bath at the bottom of the reactor. This residual bath should be equipped with a secondary cooling loop

  9. Fuel assembly and reactor core

    International Nuclear Information System (INIS)

    Aoyama, Motoo; Koyama, Jun-ichi; Uchikawa, Sadao; Bessho, Yasunori; Nakajima, Akiyoshi; Maruyama, Hiromi; Ozawa, Michihiro; Nakamura, Mitsuya.

    1990-01-01

    The present invention concerns fuel assemblies charged in a BWR type reactor and the reactor core. The fuel assembly comprises fuel rods containing burnable poisons and fuel rods not containing burnable poisons. Both of the highest and the lowest gadolinia concentrations of the fuel rods containing gadolinia as burnable poisons are present in the lower region of the fuel assembly. This can increase the spectral shift effect without increasing the maximum linear power density. (I.N.)

  10. Accelerator driven sub-critical core

    Science.gov (United States)

    McIntyre, Peter M; Sattarov, Akhdiyor

    2015-03-17

    Systems and methods for operating an accelerator driven sub-critical core. In one embodiment, a fission power generator includes a sub-critical core and a plurality of proton beam generators. Each of the proton beam generators is configured to concurrently provide a proton beam into a different area of the sub-critical core. Each proton beam scatters neutrons within the sub-critical core. The plurality of proton beam generators provides aggregate power to the sub-critical core, via the proton beams, to scatter neutrons sufficient to initiate fission in the sub-critical core.

  11. Emergency reactor core cooling facility

    International Nuclear Information System (INIS)

    Yoshikawa, Kazuhiro; Kinoshita, Shoichiro; Iwata, Yasutaka.

    1996-01-01

    The present invention provides an emergency reactor core cooling device for a BWR type nuclear power plant. Namely, D/S pit (gas/water separator storage pool) water is used as a water source for the emergency reactor core cooling facility upon occurrence of loss of coolant accidents (LOCA) by introducing the D/S pit water to the emergency reactor core cooling (ECCS) pump. As a result, the function as the ECCS facility can be eliminated from the function of the condensate storage tank which has been used as the ECCS facility. If the function is unnecessary, the level of quality control and that of earthquake resistance of the condensate storage tank can be lowered to a level of ordinary facilities to provide an effect of reducing the cost. On the other hand, since the D/S pit as the alternative water source is usually a facility at high quality control level and earthquake resistant level, there is no problem. The quality of the water in the D/S pit can be maintained constant by elevating pressure of the D/S pit water by a suppression pool cleanup (SPCU) pump to pass it through a filtration desalter thereby purifying the D/S pit water during the plant operation. (I.S.)

  12. Conceptual design of PFBR core

    International Nuclear Information System (INIS)

    Lee, S.M.; Govindarajan, S.; Indira, R.; John, T.M.; Mohanakrishnan, P.; Shankar Singh, R.; Bhoje, S.B.

    1996-01-01

    The design options selected for the core of the 500 MWe Prototype Fast Breeder Reactor are presented. PFBR has a conventional mixed oxide fuel core of homogeneous type with two enrichment zones for power flattening and with radial and axial blankets to make the reactor self-sustaining in fissile material. Pin diameter has been selected for minimization of fissile inventory. Considerations for the choice of number of pins per subassembly, integrated versus separate axial blankets, and other pin and subassembly parameters are discussed. As the core size is moderate, no special schemes for reducing the maximum positive sodium voiding coefficient is envisages. Two independent, diverse fast acting shutdown systems working in fail-safe mode are selected. The number of absorber rods has been minimized by choosing a layout for maximum antishadow effect. Nine control and safety rods are distributed in two rods for power flattening by differential insertion. Three Diverse Safety Rods, are also provided which are normally fully withdrawn. The optimization of layout of radial and axial shielding and adequacy of flux at detector location are also discussed. (author). 2 figs

  13. Grain alignment in starless cores

    Energy Technology Data Exchange (ETDEWEB)

    Jones, T. J.; Bagley, M. [Minnesota Institute for Astrophysics, University of Minnesota, Minneapolis, MN 55455 (United States); Krejny, M. [Cree Inc., 4600 Silicon Dr., Durham, NC (United States); Andersson, B.-G. [SOFIA Science Center, USRA, Moffett Field, CA (United States); Bastien, P., E-mail: tjj@astro.umn.edu [Centre de recherche en astrophysique du Québec and Départment de Physique, Université de Montréal, Montréal (Canada)

    2015-01-01

    We present near-IR polarimetry data of background stars shining through a selection of starless cores taken in the K band, probing visual extinctions up to A{sub V}∼48. We find that P{sub K}/τ{sub K} continues to decline with increasing A{sub V} with a power law slope of roughly −0.5. Examination of published submillimeter (submm) polarimetry of starless cores suggests that by A{sub V}≳20 the slope for P versus τ becomes ∼−1, indicating no grain alignment at greater optical depths. Combining these two data sets, we find good evidence that, in the absence of a central illuminating source, the dust grains in dense molecular cloud cores with no internal radiation source cease to become aligned with the local magnetic field at optical depths greater than A{sub V}∼20. A simple model relating the alignment efficiency to the optical depth into the cloud reproduces the observations well.

  14. Emergency reactor core cooling facility

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, Kazuhiro; Kinoshita, Shoichiro; Iwata, Yasutaka

    1996-11-01

    The present invention provides an emergency reactor core cooling device for a BWR type nuclear power plant. Namely, D/S pit (gas/water separator storage pool) water is used as a water source for the emergency reactor core cooling facility upon occurrence of loss of coolant accidents (LOCA) by introducing the D/S pit water to the emergency reactor core cooling (ECCS) pump. As a result, the function as the ECCS facility can be eliminated from the function of the condensate storage tank which has been used as the ECCS facility. If the function is unnecessary, the level of quality control and that of earthquake resistance of the condensate storage tank can be lowered to a level of ordinary facilities to provide an effect of reducing the cost. On the other hand, since the D/S pit as the alternative water source is usually a facility at high quality control level and earthquake resistant level, there is no problem. The quality of the water in the D/S pit can be maintained constant by elevating pressure of the D/S pit water by a suppression pool cleanup (SPCU) pump to pass it through a filtration desalter thereby purifying the D/S pit water during the plant operation. (I.S.)

  15. Reactor core of nuclear reactor

    International Nuclear Information System (INIS)

    Sasagawa, Masaru; Masuda, Hiroyuki; Mogi, Toshihiko; Kanazawa, Nobuhiro.

    1994-01-01

    In a reactor core, a fuel inventory at an outer peripheral region is made smaller than that at a central region. Fuel assemblies comprising a small number of large-diameter fuel rods are used at the central region and fuel assemblies comprising a great number of smalldiameter fuel rods are used at the outer peripheral region. Since a burning degradation rate of the fuels at the outer peripheral region can be increased, the burning degradation rate at the infinite multiplication factor of fuels at the outer region can substantially be made identical with that of the fuels in the inner region. As a result, the power distribution in the direction of the reactor core can be flattened throughout the entire period of the burning cycle. Further, it is also possible to make the degradation rate of fuels at the outer region substantially identical with that of fuels at the inner side. A power peak formed at the outer circumferential portion of the reactor core of advanced burning can be lowered to improve the fuel integrity, and also improve the reactor safety and operation efficiency. (N.H.)

  16. Ultrastructural Localization and Molecular Associations of HCV Capsid Protein in Jurkat T Cells

    Directory of Open Access Journals (Sweden)

    Cecilia Fernández-Ponce

    2018-01-01

    Full Text Available Hepatitis C virus core protein is a highly basic viral protein that multimerizes with itself to form the viral capsid. When expressed in CD4+ T lymphocytes, it can induce modifications in several essential cellular and biological networks. To shed light on the mechanisms underlying the alterations caused by the viral protein, we have analyzed HCV-core subcellular localization and its associations with host proteins in Jurkat T cells. In order to investigate the intracellular localization of Hepatitis C virus core protein, we have used a lentiviral system to transduce Jurkat T cells and subsequently localize the protein using immunoelectron microscopy techniques. We found that in Jurkat T cells, Hepatitis C virus core protein mostly localizes in the nucleus and specifically in the nucleolus. In addition, we performed pull-down assays combined with Mass Spectrometry Analysis, to identify proteins that associate with Hepatitis C virus core in Jurkat T cells. We found proteins such as NOLC1, PP1γ, ILF3, and C1QBP implicated in localization and/or traffic to the nucleolus. HCV-core associated proteins are implicated in RNA processing and RNA virus infection as well as in functions previously shown to be altered in Hepatitis C virus core expressing CD4+ T cells, such as cell cycle delay, decreased proliferation, and induction of a regulatory phenotype. Thus, in the current work, we show the ultrastructural localization of Hepatitis C virus core and the first profile of HCV core associated proteins in T cells, and we discuss the functions and interconnections of these proteins in molecular networks where relevant biological modifications have been described upon the expression of Hepatitis C virus core protein. Thereby, the current work constitutes a necessary step toward understanding the mechanisms underlying HCV core mediated alterations that had been described in relevant biological processes in CD4+ T cells.

  17. Drilling equipment for difficult coring conditions: a new type of core lifter and triple tube core barrel

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, J B

    1968-08-01

    Although considerable improvements in diamond drilling equipment have been made since the early 1950's, deficiencies in existing equipment led to the development of a new type core lifter and special 20 ft triple tube core barrel designed to operate in bad coring conditions. It is claimed that although developed essentially for coal drilling, the new equipment could be adapted to other fields of diamond drilling with the cost advantage of increased life of the core lifter.

  18. Total protein

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003483.htm Total protein To use the sharing features on this page, please enable JavaScript. The total protein test measures the total amount of two classes ...

  19. Proteins engineering

    International Nuclear Information System (INIS)

    2000-01-01

    At the - Departement d'Ingenierie et d'etudes de proteines (Deip) of the CEA more than seventy researchers are working hard to understand the function of proteins. For that they use the molecular labelling technique (F.M.)

  20. Whey Protein

    Science.gov (United States)

    ... reliable information about the safety of taking whey protein if you are pregnant or breast feeding. Stay on the safe side and avoid use. Milk allergy: If you are allergic to cow's milk, avoid using whey protein.

  1. Whole core transport calculation for the VHTR hexagonal core

    International Nuclear Information System (INIS)

    Cho, J. Y.; Kim, K. S.; Lee, C. C.; Joo, H. G.

    2007-01-01

    Recently, the DeCART code which performs the whole core calculation by coupling the radial MOC transport kernel with the axial nodal kernel has equipped a kernel to deal with the hexagonal geometry and applied to the VHTR hexagonal core to examine the accuracy and the computational efficiency of the implemented kernel. The implementation includes a modular ray tracing module based on the hexagonal assembly and a multi-group CMFD module to perform an efficient transport calculation. The requirements for the modular ray are: (1) the assembly based path linking and (2) the complete reflection capabilities. The first requirement is met by adjusting the azimuthal angle and the ray spacing for the modular ray to construct a core ray by the path linking. The second requirement is met by expanding the constructed azimuthal angle in the range of [0,30 degree] to the remained range to reflect completely at the core boundaries. The considered reflecting surface angles for the complete reflection are 30n's (n=1,2,1,12). The CMFD module performs the equivalent diffusion calculation to the radial MOC transport calculation based on the homogenized structure units. The structure units include the hexagonal pin cells and gap cells appearing at the assembly boundary. Therefore, the CMFD module is programmed to deal with the unstructured cells such as the gap cells. The CMFD equation consists of the two parts of (1) the conventional FDM and (2) the current corrective parts. Since the second part of the CMFD equation guarantees the reproducibility of the radial MOC transport solutions for the cell averaged reaction rate and the net current at the cell surfaces, how to build the first part of the CMFD equation is not important. Therefore, the first part of the CMFD equation is roughly built by using the normal distance from the gravity center to the surface. The VHTR core uses helium as a coolant which is realized as a void hole in a neutronics calculation. This void hole which

  2. Nuclear characteristic simulation device for reactor core

    International Nuclear Information System (INIS)

    Arakawa, Akio; Kobayashi, Yuji.

    1994-01-01

    In a simulation device for nuclear characteristic of a PWR type reactor, there are provided a one-dimensional reactor core dynamic characteristic model for simulating one-dimensional neutron flux distribution in the axial direction of the reactor core and average reactor power based on each of inputted signals of control rod pattern, a reactor core flow rate, reactor core pressure and reactor core inlet enthalphy, and a three-dimensional reactor core dynamic characteristic mode for simulating three-dimensional power distribution of the reactor core, and a nuclear instrumentation model for calculating read value of the nuclear instrumentation disposed in the reactor based on the average reactor core power and the reactor core three-dimensional power distribution. A one-dimensional neutron flux distribution in the axial direction of the reactor core, a reactor core average power, a reactor core three-dimensional power distribution and a nuclear instrumentation read value are calculated. As a result, the three-dimensional power distribution and the power level are continuously calculated. Further, since the transient change of the three-dimensional neutron flux distribution is calculated accurately on real time, more actual response relative to a power monitoring device of the reactor core and operation performance can be simulated. (N.H.)

  3. HKC: An Algorithm to Predict Protein Complexes in Protein-Protein Interaction Networks

    Directory of Open Access Journals (Sweden)

    Xiaomin Wang

    2011-01-01

    Full Text Available With the availability of more and more genome-scale protein-protein interaction (PPI networks, research interests gradually shift to Systematic Analysis on these large data sets. A key topic is to predict protein complexes in PPI networks by identifying clusters that are densely connected within themselves but sparsely connected with the rest of the network. In this paper, we present a new topology-based algorithm, HKC, to detect protein complexes in genome-scale PPI networks. HKC mainly uses the concepts of highest k-core and cohesion to predict protein complexes by identifying overlapping clusters. The experiments on two data sets and two benchmarks show that our algorithm has relatively high F-measure and exhibits better performance compared with some other methods.

  4. Study of the mechanism of clamping and detachment of a core sample by core lever lifters

    Energy Technology Data Exchange (ETDEWEB)

    Barabashkin, I I; Mizyakin, V M; Nikitin, S V

    1981-01-01

    Geometric dimensions of the basic elements of a core lifter should be determined depending on the clamping conditions. The changes should be determined depending on the conditions of the core sample diameter, critical angle between the lever and the core samples in the necessary depth of submersion of the contact edge of the lever into its surface. The core lifter KTsRZ-80 with eccentric core reception makes it possible to arrange more efficiently the core removing elements on the edge of the band. The use of the core lifters with eccentric plan of arrangement of the levers and their optimal length increases the removal of the core sample.

  5. The Phospholipid:Diacylglycerol Acyltransferase Lro1 Is Responsible for Hepatitis C Virus Core-Induced Lipid Droplet Formation in a Yeast Model System.

    Directory of Open Access Journals (Sweden)

    Shingo Iwasa

    Full Text Available Chronic infection with the hepatitis C virus frequently induces steatosis, which is a significant risk factor for liver pathogenesis. Steatosis is characterized by the accumulation of lipid droplets in hepatocytes. The structural protein core of the virus induces lipid droplet formation and localizes on the surface of the lipid droplets. However, the precise molecular mechanisms for the core-induced formation of lipid droplets remain elusive. Recently, we showed that the expression of the core protein in yeast as a model system could induce lipid droplet formation. In this study, we probed the cellular factors responsible for the formation of core-induced lipid-droplets in yeast cells. We demonstrated that one of the enzymes responsible for triglyceride synthesis, a phospholipid:diacylglycerol acyltransferase (Lro1, is required for the core-induced lipid droplet formation. While core proteins inhibit Lro1 degradation and alter Lro1 localization, the characteristic localization of Lro1 adjacent to the lipid droplets appeared to be responsible for the core-induced lipid droplet formation. RNA virus genomes have evolved using high mutation rates to maintain their ability to replicate. Our observations suggest a functional relationship between the core protein with hepatocytes and yeast cells. The possible interactions between core proteins and the endoplasmic reticulum membrane affect the mobilization of specific proteins.

  6. Investigating the translation of Earth's inner core

    DEFF Research Database (Denmark)

    Day, Elizabeth A; Cormier, Vernon F; Geballe, Zachary M

    2012-01-01

    The Earth’s inner core provides unique insights into processes that are occurring deep within our Earth today, as well as processes that occurred in the past. The seismic structure of the inner core is complex, and is dominated by anisotropic and isotropic differences between the Eastern...... for models of a translating inner core. Additionally, we investigate the structure at the base of the outer core and the inner core boundary by analyzing PKP-Cdiff waves. The search for observable PKP-Cdiff is particularly concentrated in regions that are predicted to be actively freezing and melting...... and Western ‘hemispheres’ of the inner core. Recent geodynamical models suggest that this hemispherical dichotomy can be explained by a fast translation of the inner core. In these models one side of the inner core is freezing, while the other side is melting, leading to the development of different seismic...

  7. Evaluation of core distortion in FBR

    International Nuclear Information System (INIS)

    Ikarimoto, I.; Tanaka, M.; Okubo, Y.

    1984-01-01

    The analyses of FBR's core distortion are mainly performed in order to evaluate the following items: 1) Change of reactivity; 2) Force at pads on core assemblies; 3) Withdrawal force at refueling; 4) Loading, refueling and residual deviations of wrapper tubes (core assemblies) at the top; 5) Bowing modes of guide tubes for control rods. The analysis of core distortion are performed by using computer program for two-dimensional row deformation analysis or three-dimensional core deformation if necessary, considering these evaluated items which become design conditions. This report shows the relationship between core deformation analysis and component design, a point of view of choosing an analysis program for design considering core characteristics, and computing examples of core deformation of prototype class reactor by the above code. (author)

  8. Device for removal of oriented core

    Energy Technology Data Exchange (ETDEWEB)

    Shakhmalov, A.M.

    1981-05-04

    A device for removal of an oriented core, which contains an external core barrel, connected with a gear, a rock-crushing bit, nonrotary core-receiving pipe, and a core marker, placed in the core-receiving pipe and connected kinematically with the external core barrel and gear, is distinguished by the fact that in order to increase the accuracy of determination of the spatial orientation of the core the gear of the core barrel and the marker come in the form of an electric drill, and a magnetic compass witha remote-fix indicator is attached to its housing. The device is also distinguished by the fact that it is equipped with an auxillary marker positioned symmetrically with respect to the first one.

  9. Design Principles for Synthesizable Processor Cores

    DEFF Research Database (Denmark)

    Schleuniger, Pascal; McKee, Sally A.; Karlsson, Sven

    2012-01-01

    As FPGAs get more competitive, synthesizable processor cores become an attractive choice for embedded computing. Currently popular commercial processor cores do not fully exploit current FPGA architectures. In this paper, we propose general design principles to increase instruction throughput...

  10. TMI-2 core bore acquisition summary report

    International Nuclear Information System (INIS)

    Tolman, E.L.; Smith, R.P.; Martin, M.R.; McCardell, R.K.; Broughton, J.M.

    1986-09-01

    Core bore samples were obtained from the severely damaged TMI-2 core during July and August, 1986. A description of the TMI-2 core bore drilling unit used to obtain samples; a summary and discussion of the data from the ten core bore segments which were obtained; and the initial results of analysis and evaluation of these data are presented in this report. The impact of the major findings relative to our understanding of the accident scenario is also discussed

  11. Core Processes: Earth's eccentric magnetic field

    DEFF Research Database (Denmark)

    Finlay, Chris

    2012-01-01

    Earth’s magnetic field is characterized by a puzzling hemispheric asymmetry. Calculations of core dynamo processes suggest that lopsided growth of the planet’s inner core may be part of the cause.......Earth’s magnetic field is characterized by a puzzling hemispheric asymmetry. Calculations of core dynamo processes suggest that lopsided growth of the planet’s inner core may be part of the cause....

  12. Core trénink ve florbale

    OpenAIRE

    Mašková, Alžběta

    2014-01-01

    Title: Use of core training in floorball Objectives: Present an overview of research papers regarding core training and its possible use in floorball Tasks: First aim of this thesis is to provide description and explanation of the core training by using available literature, research papers, bachelor or magister thesis and also thesis of the coaching school. Second aim is to analyze the necessary components of floorball player's performance relative to the core training. This is followed by a...

  13. Integration of Biosafety into Core Facility Management

    OpenAIRE

    Fontes, Benjamin

    2013-01-01

    This presentation will discuss the implementation of biosafety policies for small, medium and large core laboratories with primary shared objectives of ensuring the control of biohazards to protect core facility operators and assure conformity with applicable state and federal policies, standards and guidelines. Of paramount importance is the educational process to inform core laboratories of biosafety principles and policies and to illustrate the technology and process pathways of the core l...

  14. Temporal Change of Seismic Earth's Inner Core Phases: Inner Core Differential Rotation Or Temporal Change of Inner Core Surface?

    Science.gov (United States)

    Yao, J.; Tian, D.; Sun, L.; Wen, L.

    2017-12-01

    Since Song and Richards [1996] first reported seismic evidence for temporal change of PKIKP wave (a compressional wave refracted in the inner core) and proposed inner core differential rotation as its explanation, it has generated enormous interests in the scientific community and the public, and has motivated many studies on the implications of the inner core differential rotation. However, since Wen [2006] reported seismic evidence for temporal change of PKiKP wave (a compressional wave reflected from the inner core boundary) that requires temporal change of inner core surface, both interpretations for the temporal change of inner core phases have existed, i.e., inner core rotation and temporal change of inner core surface. In this study, we discuss the issue of the interpretation of the observed temporal changes of those inner core phases and conclude that inner core differential rotation is not only not required but also in contradiction with three lines of seismic evidence from global repeating earthquakes. Firstly, inner core differential rotation provides an implausible explanation for a disappearing inner core scatterer between a doublet in South Sandwich Islands (SSI), which is located to be beneath northern Brazil based on PKIKP and PKiKP coda waves of the earlier event of the doublet. Secondly, temporal change of PKIKP and its coda waves among a cluster in SSI is inconsistent with the interpretation of inner core differential rotation, with one set of the data requiring inner core rotation and the other requiring non-rotation. Thirdly, it's not reasonable to invoke inner core differential rotation to explain travel time change of PKiKP waves in a very small time scale (several months), which is observed for repeating earthquakes in Middle America subduction zone. On the other hand, temporal change of inner core surface could provide a consistent explanation for all the observed temporal changes of PKIKP and PKiKP and their coda waves. We conclude that

  15. Common Core: Teaching Optimum Topic Exploration (TOTE)

    Science.gov (United States)

    Karge, Belinda Dunnick; Moore, Roxane Kushner

    2015-01-01

    The Common Core has become a household term and yet many educators do not understand what it means. This article explains the historical perspectives of the Common Core and gives guidance to teachers in application of Teaching Optimum Topic Exploration (TOTE) necessary for full implementation of the Common Core State Standards. An effective…

  16. The core health science library in Canada.

    Science.gov (United States)

    Huntley, J L

    1974-04-01

    Core lists in Canada are characterized by regional differences. The lists of current importance are: (1) the British Columbia acquisitions guide for hospital libraries, (2) three Saskatchewan lists for hospitals of different sizes, (3) a core list recommended for Ontario hospitals, (4) Quebec core lists, including French language lists.

  17. Improving Core Strength to Prevent Injury

    Science.gov (United States)

    Oliver, Gretchen D.; Adams-Blair, Heather R.

    2010-01-01

    Regardless of the sport or skill, it is essential to have correct biomechanical positioning, or postural control, in order to maximize energy transfer. Correct postural control requires a strong, stable core. A strong and stable core allows one to transfer energy effectively as well as reduce undue stress. An unstable or weak core, on the other…

  18. Simplifying the ELA Common Core; Demystifying Curriculum

    Science.gov (United States)

    Schmoker, Mike; Jago, Carol

    2013-01-01

    The English Language Arts (ELA) Common Core State Standards ([CCSS], 2010) could have a transformational effect on American education. Though the process seems daunting, one can begin immediately integrating the essence of the ELA Common Core in every subject area. This article shows how one could implement the Common Core and create coherent,…

  19. Ubuntu Core Snaps for Science

    Science.gov (United States)

    Wyngaard, J.

    2017-12-01

    A key challenge in the burgeoning sector of IoT (Internet of Things) is ensuring device and communication security. Ubuntu Core's approach to this is the use of 'snaps'. Along side this growth, scientists are increasingly utilising the many new low cost sensors now available. This work prototypes the use of snaps as a possible avenue to reducing the barrier to entry for scientific use of these low cost sensors while also ensuring proper meta-data is captured. Snaps are contained applications that have been signed. This means that a snap application is unable to read or write to any area of the system beyond its assigned reach, thereby significantly limiting the possible impact of any break in security higher up the stack. Further, application and system updates are automatically verified as authentic before being applied. Additionally, on an embedded system running Ubuntu Core the hardware interface (Gadget), kernel, and OS (Core) are all also snaps and therefore also have acquired these same gains. The result is an architecture that enables: (1) Secure, robust, remote automatic updates of both the OS and applications. (2) A user friendly deployment mechanism.(3) A easy to maintain means of supporting multiple platforms. The above is primarily targeted at non-academic domains, however, it is proposed that the Scientific community can benefit from it too. This work therefore prototypes a snap for sensors on board a small Unmanned Aircraft System (sUAS). For demonstration purposes this snap specifically targets connecting a popular low cost CO2 meter to a Raspberry Pi3 and the popular open source sUAS autopilot Arducopter.

  20. Protein-protein interaction site predictions with three-dimensional probability distributions of interacting atoms on protein surfaces.

    Directory of Open Access Journals (Sweden)

    Ching-Tai Chen

    Full Text Available Protein-protein interactions are key to many biological processes. Computational methodologies devised to predict protein-protein interaction (PPI sites on protein surfaces are important tools in providing insights into the biological functions of proteins and in developing therapeutics targeting the protein-protein interaction sites. One of the general features of PPI sites is that the core regions from the two interacting protein surfaces are complementary to each other, similar to the interior of proteins in packing density and in the physicochemical nature of the amino acid composition. In this work, we simulated the physicochemical complementarities by constructing three-dimensional probability density maps of non-covalent interacting atoms on the protein surfaces. The interacting probabilities were derived from the interior of known structures. Machine learning algorithms were applied to learn the characteristic patterns of the probability density maps specific to the PPI sites. The trained predictors for PPI sites were cross-validated with the training cases (consisting of 432 proteins and were tested on an independent dataset (consisting of 142 proteins. The residue-based Matthews correlation coefficient for the independent test set was 0.423; the accuracy, precision, sensitivity, specificity were 0.753, 0.519, 0.677, and 0.779 respectively. The benchmark results indicate that the optimized machine learning models are among the best predictors in identifying PPI sites on protein surfaces. In particular, the PPI site prediction accuracy increases with increasing size of the PPI site and with increasing hydrophobicity in amino acid composition of the PPI interface; the core interface regions are more likely to be recognized with high prediction confidence. The results indicate that the physicochemical complementarity patterns on protein surfaces are important determinants in PPIs, and a substantial portion of the PPI sites can be predicted