The PsB glycoprotein complex is secreted as a preassembled precursor of the spore coat in Dictyostelium discoideum.

Science.gov (United States)

Watson, N; McGuire, V; Alexander, S

1994-09-01

The PsB glycoprotein in Dictyostelium discoideum is one of a diverse group of developmentally regulated, prespore-cell-specific proteins, that contain a common O-linked oligosaccharide. This post-translational modification is dependent on the wild-type modB allele. The PsB protein exists as part of a multiprotein complex of six different proteins, which have different post-translational modifications and are held together by both covalent and non-covalent interactions (Watson et al. (1993). J. Biol. Chem. 268, 22634-22641). In this study we have used microscopic and biochemical analyses to examine the cellular localization and function of the PsB complex during development. We found that the PsB complex first accumulates in prespore vesicles in slug cells and is secreted later during culmination and becomes localized to both the extracellular matrix of the apical spore mass of mature fruiting bodies and to the inner layer of the spore coat. The PsB associated with the spore coat is covalently bound by disulfide bridges. The PsB protein always exists in a multiprotein complex, but the composition of the PsB complex changes during secretion and spore maturation. Some of the PsB complex proteins have been identified as spore coat proteins. These data demonstrate that some of the proteins that form the spore coat exist as a preassembled precursor complex. The PsB complex is secreted in a developmentally regulated manner during the process of spore differentiation, at which time proteins of the complex, as well as additional spore coat proteins, become covalently associated in at least two forms of extracellular matrix: the interspore matrix and the spore coat. These and other studies show that proteins with modB dependent O-linked oligosaccharides are involved in a wide variety of processes underlying morphogenesis in this organism. These developmental processes are the direct result of cellular mechanisms regulating protein targeting, assembly and secretion, and the

INFLUENCE OF ALPHA-1-ACID GLYCOPROTEIN UPON PRODUCTION OF CYTOKINES BY PERIPHERAL BLOOD MONONUCLEARS

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М. V. Osikov

2007-01-01

Full Text Available Abstract. Alpha-1-acid glycoprotein (orosomucoid is a multifunctional acute phase reactant belonging to the family of lipocalines from plasma alpha-2 globulin fraction. In present study, we investigated dosedependent effects of orosomucoid upon secretion of IL-1â, IL-2, IL-3, IL-4 by mononuclear cells from venous blood of healthy volunteers. Mononuclear cells were separated by means of gradient centrifugation, followed by incubation for 24 hours with 250, 500, or 1000 mcg of orosomucoid per ml RPMI-1640 medium (resp., low, medium and high dose. The levels of cytokine production were assayed by ELISA technique. Orosomucoid-induced secretion of IL-1â and IL-4 was increased, whereas IL-3 secretion was inhibited. IL-2 production was suppressed at low doses of orosomucoid, and stimulated at medium and high doses. The effect of alpha-1-acid glycoprotein upon production of IL-2, IL-3 and IL-4 was dose-dependent. Hence, these data indicate that orosomucoid is capable of modifying IL-1â, IL-2, IL-3, and IL-4 secretion by blood mononuclear cells.

The amino-terminus of the hepatitis C virus (HCV p7 viroporin and its cleavage from glycoprotein E2-p7 precursor determine specific infectivity and secretion levels of HCV particle types.

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Solène Denolly

2017-12-01

Full Text Available Viroporins are small transmembrane proteins with ion channel activities modulating properties of intracellular membranes that have diverse proviral functions. Hepatitis C virus (HCV encodes a viroporin, p7, acting during assembly, envelopment and secretion of viral particles (VP. HCV p7 is released from the viral polyprotein through cleavage at E2-p7 and p7-NS2 junctions by signal peptidase, but also exists as an E2p7 precursor, of poorly defined properties. Here, we found that ectopic p7 expression in HCVcc-infected cells reduced secretion of particle-associated E2 glycoproteins. Using biochemical assays, we show that p7 dose-dependently slows down the ER-to-Golgi traffic, leading to intracellular retention of E2, which suggested that timely E2p7 cleavage and p7 liberation are critical events to control E2 levels. By studying HCV mutants with accelerated E2p7 processing, we demonstrate that E2p7 cleavage controls E2 intracellular expression and secretion levels of nucleocapsid-free subviral particles and infectious virions. In addition, our imaging data reveal that, following p7 liberation, the amino-terminus of p7 is exposed towards the cytosol and coordinates the encounter between NS5A and NS2-based assembly sites loaded with E1E2 glycoproteins, which subsequently leads to nucleocapsid envelopment. We identify punctual mutants at p7 membrane interface that, by abrogating NS2/NS5A interaction, are defective for transmission of infectivity owing to decreased secretion of core and RNA and to increased secretion of non/partially-enveloped particles. Altogether, our results indicate that the retarded E2p7 precursor cleavage is essential to regulate the intracellular and secreted levels of E2 through p7-mediated modulation of the cell secretory pathway and to unmask critical novel assembly functions located at p7 amino-terminus.

Secreted and Transmembrane Wnt Inhibitors and Activators

Science.gov (United States)

Cruciat, Cristina-Maria; Niehrs, Christof

2013-01-01

Signaling by the Wnt family of secreted glycoproteins plays important roles in embryonic development and adult homeostasis. Wnt signaling is modulated by a number of evolutionarily conserved inhibitors and activators. Wnt inhibitors belong to small protein families, including sFRP, Dkk, WIF, Wise/SOST, Cerberus, IGFBP, Shisa, Waif1, APCDD1, and Tiki1. Their common feature is to antagonize Wnt signaling by preventing ligand–receptor interactions or Wnt receptor maturation. Conversely, the Wnt activators, R-spondin and Norrin, promote Wnt signaling by binding to Wnt receptors or releasing a Wnt-inhibitory step. With few exceptions, these antagonists and agonists are not pure Wnt modulators, but also affect additional signaling pathways, such as TGF-β and FGF signaling. Here we discuss their interactions with Wnt ligands and Wnt receptors, their role in developmental processes, as well as their implication in disease. PMID:23085770

Rotavirus NSP4 is secreted from infected cells as an oligomeric lipoprotein and binds to glycosaminoglycans on the surface of non-infected cells

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Didsbury Alicia

2011-12-01

Full Text Available Abstract Background Nonstructural glycoprotein 4 (NSP4 encoded by rotavirus is the only viral protein currently believed to function as an enterotoxin. NSP4 is synthesized as an intracellular transmembrane glycoprotein and as such is essential for virus assembly. Infection of polarized Caco-2 cells with rotavirus also results in the secretion of glycosylated NSP4 apparently in a soluble form despite retention of its transmembrane domain. We have examined the structure, solubility and cell-binding properties of this secreted form of NSP4 to further understand the biochemical basis for its enterotoxic function. We show here that NSP4 is secreted as discrete detergent-sensitive oligomers in a complex with phospholipids and demonstrate that this secreted form of NSP4 can bind to glycosaminoglycans present on the surface of a range of different cell types. Methods NSP4 was purified from the medium of infected cells after ultracentrifugation and ultrafiltration by successive lectin-affinity and ion exchange chromatography. Oligomerisation of NSP4 was examined by density gradient centrifugation and chemical crosslinking and the lipid content was assessed by analytical thin layer chromatography and flame ionization detection. Binding of NSP4 to various cell lines was measured using a flow cytometric-based assay. Results Secreted NSP4 formed oligomers that contained phospholipid but dissociated to a dimeric species in the presence of non-ionic detergent. The purified glycoprotein binds to the surface of various non-infected cells of distinct lineage. Binding of NSP4 to HT-29, a cell line of intestinal origin, is saturable and independent of divalent cations. Complementary biochemical approaches reveal that NSP4 binds to sulfated glycosaminoglycans on the plasma membrane. Conclusion Our study is the first to analyze an authentic (i.e. non-recombinant form of NSP4 that is secreted from virus-infected cells. Despite retention of the transmembrane domain

The glycoproteins of Marburg and Ebola virus and their potential roles in pathogenesis.

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Feldmann, H; Volchkov, V E; Volchkova, V A; Klenk, H D

1999-01-01

Filoviruses cause systemic infections that can lead to severe hemorrhagic fever in human and non-human primates. The primary target of the virus appears to be the mononuclear phagocytic system. As the virus spreads through the organism, the spectrum of target cells increases to include endothelial cells, fibroblasts, hepatocytes, and many other cells. There is evidence that the filovirus glycoprotein plays an important role in cell tropism, spread of infection, and pathogenicity. Biosynthesis of the glycoprotein forming the spikes on the virion surface involves cleavage by the host cell protease furin into two disulfide linked subunits GP1 and GP2. GP1 is also shed in soluble form from infected cells. Different strains of Ebola virus show variations in the cleavability of the glycoprotein, that may account for differences in pathogenicity, as has been observed with influenza viruses and paramyxoviruses. Expression of the spike glycoprotein of Ebola virus, but not of Marburg virus, requires transcriptional editing. Unedited GP mRNA yields the nonstructural glycoprotein sGP, which is secreted extensively from infected cells. Whether the soluble glycoproteins GP1 and sGP interfere with the humoral immune response and other defense mechanisms remains to be determined.

THE ROLE OF P-GLYCOPROTEIN IN RATIONAL PHARMACOTHERAPY IN CARDIOLOGY

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A. V. Shulkin

2015-09-01

Full Text Available On the basis of the analysis of published data the role of P-glycoprotein, carrier protein, in rational pharmacotherapy in cardiology was shown on the example of its substrates – digoxin, antiplatelet agents and anticoagulants. Determination of C3435T polymorphism of multidrug resistance gene (MDR1, encoding P-glycoprotein, in pharmacotherapy with digoxin, antiplatelet drugs (clopidogrel tikagrelol, prasugrel and anticoagulants (dabigatran etexilate, rivaroxaban, edoxaban is not feasible in routine practice. Drug in- teractions have clinical implications for the efficacy and safety of pharmacotherapy in coadministration of these drugs with P-glycoprotein substrates, inducers and inhibitors.

Glycoprotein component of plant cell walls

International Nuclear Information System (INIS)

Cooper, J.B.; Chen, J.A.; Varner, J.E.

1984-01-01

The primary wall surrounding most dicotyledonous plant cells contains a hydroxyproline-rich glycoprotein (HRGP) component named extensin. A small group of glycopeptides solubilized from isolated cell walls by proteolysis contained a repeated pentapeptide glycosylated by tri- and tetraarabinosides linked to hydroxyproline and, by galactose, linked to serine. Recently, two complementary approaches to this problem have provided results which greatly increase the understanding of wall extensin. In this paper the authors describe what is known about the structure of soluble extensin secreted into the walls of the carrot root cells

A novel function of N-linked glycoproteins, alpha-2-HS-glycoprotein and hemopexin: Implications for small molecule compound-mediated neuroprotection.

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Takuya Kanno

Full Text Available Therapeutic agents to the central nervous system (CNS need to be efficiently delivered to the target site of action at appropriate therapeutic levels. However, a limited number of effective drugs for the treatment of neurological diseases has been developed thus far. Further, the pharmacological mechanisms by which such therapeutic agents can protect neurons from cell death have not been fully understood. We have previously reported the novel small-molecule compound, 2-[mesityl(methylamino]-N-[4-(pyridin-2-yl-1H-imidazol-2-yl] acetamide trihydrochloride (WN1316, as a unique neuroprotectant against oxidative injury and a highly promising remedy for the treatment of amyotrophic lateral sclerosis (ALS. One of the remarkable characteristics of WN1316 is that its efficacious doses in ALS mouse models are much less than those against oxidative injury in cultured human neuronal cells. It is also noted that the WN1316 cytoprotective activity observed in cultured cells is totally dependent upon the addition of fetal bovine serum in culture medium. These findings led us to postulate some serum factors being tightly linked to the WN1316 efficacy. In this study, we sieved through fetal bovine serum proteins and identified two N-linked glycoproteins, alpha-2-HS-glycoprotein (AHSG and hemopexin (HPX, requisites to exert the WN1316 cytoprotective activity against oxidative injury in neuronal cells in vitro. Notably, the removal of glycan chains from these molecules did not affect the WN1316 cytoprotective activity. Thus, two glycoproteins, AHSG and HPX, represent a pivotal glycoprotein of the cytoprotective activity for WN1316, showing a concrete evidence for the novel glycan-independent function of serum glycoproteins in neuroprotective drug efficacy.

The elicitin-like glycoprotein, ELI025, is secreted by the pathogenic oomycete Pythium insidiosum and evades host antibody responses.

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Tassanee Lerksuthirat

Full Text Available Pythium insidiosum is a unique oomycete that can infect humans and animals. Patients with a P. insidiosum infection (pythiosis have high rates of morbidity and mortality. The pathogen resists conventional antifungal drugs. Information on the biology and pathogenesis of P. insidiosum is limited. Many pathogens secrete proteins, known as effectors, which can affect the host response and promote the infection process. Elicitins are secretory proteins and are found only in the oomycetes, primarily in Phytophthora and Pythium species. In plant-pathogenic oomycetes, elicitins function as pathogen-associated molecular pattern molecules, sterol carriers, and plant defense stimulators. Recently, we reported a number of elicitin-encoding genes from the P. insidiosum transcriptome. The function of elicitins during human infections is unknown. One of the P. insidiosum elicitin-encoding genes, ELI025, is highly expressed and up-regulated at body temperature. This study aims to characterize the biochemical, immunological, and genetic properties of the elicitin protein, ELI025. A 12.4-kDa recombinant ELI025 protein (rELI025 was expressed in Escherichia coli. Rabbit anti-rELI025 antibodies reacted strongly with the native ELI025 in P. insidiosum's culture medium. The detected ELI025 had two isoforms: glycosylated and non-glycosylated. ELI025 was not immunoreactive with sera from pythiosis patients. The region near the transcriptional start site of ELI025 contained conserved oomycete core promoter elements. In conclusion, ELI025 is a small, abundant, secreted glycoprotein that evades host antibody responses. ELI025 is a promising candidate for development of diagnostic and therapeutic targets for pythiosis.

Spatial Localization of the Ebola Virus Glycoprotein Mucin-Like Domain Determined by Cryo-Electron Tomography

OpenAIRE

Tran, Erin E. H.; Simmons, James A.; Bartesaghi, Alberto; Shoemaker, Charles J.; Nelson, Elizabeth; White, Judith M.; Subramaniam, Sriram

2014-01-01

The Ebola virus glycoprotein mucin-like domain (MLD) is implicated in Ebola virus cell entry and immune evasion. Using cryo-electron tomography of Ebola virus-like particles, we determined a three-dimensional structure for the full-length glycoprotein in a near-native state and compared it to that of a glycoprotein lacking the MLD. Our results, which show that the MLD is located at the apex and the sides of each glycoprotein monomer, provide a structural template for analysis of MLD function.

Changes in the sialylation and sulfation of secreted thyrotropin in congenital hypothyroidism

International Nuclear Information System (INIS)

Gyves, P.W.; Gesundheit, N.; Thotakura, N.R.; Stannard, B.S.; DeCherney, G.S.; Weintraub, B.D.

1990-01-01

The authors have examined the oligosaccharide structure of secreted thyrotropin (TSH) in perinatal and mature rats with congenital primary hypothyroidism. Rat pituitaries from euthyroid control animals and those rendered hypothyroid by methimazole treatment were incubated with [ 3 H]glucosamine in vitro. Secreted TSH was purified, and oligosaccharides were enzymatically released and characterized by anion-exchange HPLC. In perinatal hypothyroid animals compared with control animals, oligosaccharides from TSH α and β subunits contained more species with three or more negative charges. Moreover, perinatal hypothyroid animals demonstrated a dramatic increase in the ratio of sialylated to sulfated species within oligosaccharides of the same negative charge. In mature hypothyroid 9-week-old animals compared with control animals, changes were less pronounced, suggesting that endocrine regulation of oligosaccharide structure is dependent upon the maturational state of the animal. Together, these data provide direct evidence and characterization of specific changes in the structure of a secreted pituitary glycoprotein hormone occurring as a result of in vivo endocrine alterations during early development. Moreover, they provide a potential structural basis to explain the delayed clearance of both TSH and the gonadotropins with end-organ deficiency, which may have important implications for the in vivo biological activities of these hormones

Involvement of Leishmania donovani major surface glycoprotein ...

Indian Academy of Sciences (India)

The major surface glycoprotein gp63 of the kinetoplastid protozoal parasite Leishmania is implicated as a ligand mediating uptake of the parasite into, and survival within, the host macrophage. By expressing gp63 antisense RNA from an episomal vector in L. donovani promastigotes, gp63-deficient transfectants were ...

Use of radioactive glucosamine in the perfused rat liver to prepare α1-acid glycoprotein (orosomucoid) with 3H- or 14C-labelled sialic acid and N-acetylglucosamine residues

International Nuclear Information System (INIS)

Aronson, N.N. Jr.

1982-01-01

A method was developed whereby [1- 14 C]glucosamine was used in a perfused rat liver system to prepare over 2 mg of α 1 -acid glycoprotein with highly radioactive sialic acid and glucosamine residues. The liver secreted radioactive α 1 -acid glycoprotein over a 4-6 h period, and this glycoprotein was purified from the perfusate by chromatography on DEAE-cellulose at pH3.6. The sialic acid on the isolated glycoprotein had a specific radioactivity of 3.1 Ci/mol, whereas the glucosamine-specific radioactivity was 4.3 Ci/mole. The latter amino-sugar residues on the isolated protein were only 13-fold less radioactive than the initially added [1- 14 C]glucosamine. Orosomucoid with a specific radioactivity of 31.3 μCi/mg of protein was obtainable by using [6- 3 H]glucosamine. Many other radioactive glycoproteins were found to be secreted into the perfusate by the liver. Thus this experimental system should prove useful for obtaining other serum glycoproteins with highly radioactive sugar moieties. (author)

Spatial localization of the Ebola virus glycoprotein mucin-like domain determined by cryo-electron tomography.

Science.gov (United States)

Tran, Erin E H; Simmons, James A; Bartesaghi, Alberto; Shoemaker, Charles J; Nelson, Elizabeth; White, Judith M; Subramaniam, Sriram

2014-09-01

The Ebola virus glycoprotein mucin-like domain (MLD) is implicated in Ebola virus cell entry and immune evasion. Using cryo-electron tomography of Ebola virus-like particles, we determined a three-dimensional structure for the full-length glycoprotein in a near-native state and compared it to that of a glycoprotein lacking the MLD. Our results, which show that the MLD is located at the apex and the sides of each glycoprotein monomer, provide a structural template for analysis of MLD function. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Global analysis of glycoproteins identifies markers of endotoxin tolerant monocytes and GPR84 as a modulator of TNFα expression.

Science.gov (United States)

Müller, Mario M; Lehmann, Roland; Klassert, Tilman E; Reifenstein, Stella; Conrad, Theresia; Moore, Christoph; Kuhn, Anna; Behnert, Andrea; Guthke, Reinhard; Driesch, Dominik; Slevogt, Hortense

2017-04-12

Exposure of human monocytes to lipopolysaccharide (LPS) induces a temporary insensitivity to subsequent LPS challenges, a cellular state called endotoxin tolerance. In this study, we investigated the LPS-induced global glycoprotein expression changes of tolerant human monocytes and THP-1 cells to identify markers and glycoprotein targets capable to modulate the immunosuppressive state. Using hydrazide chemistry and LC-MS/MS analysis, we analyzed glycoprotein expression changes during a 48 h LPS time course. The cellular snapshots at different time points identified 1491 glycoproteins expressed by monocytes and THP-1 cells. Label-free quantitative analysis revealed transient or long-lasting LPS-induced expression changes of secreted or membrane-anchored glycoproteins derived from intracellular membrane coated organelles or from the plasma membrane. Monocytes and THP-1 cells demonstrated marked differences in glycoproteins differentially expressed in the tolerant state. Among the shared differentially expressed glycoproteins G protein-coupled receptor 84 (GPR84) was identified as being capable of modulating pro-inflammatory TNFα mRNA expression in the tolerant cell state when activated with its ligand Decanoic acid.

A glycoprotein with anti-inflammatory properties secreted by an Aspergillus nidulans modified strain

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J. C. F. Queiroz

2007-01-01

Full Text Available Total RNA from lipopolysaccharide (LPS-stimulated rat macrophages used to treat protoplasts from an Aspergillus nidulans strain originated the RT2 regenerated strain, whose culture supernatant showed anti-inflammatory activity in Wistar rats. The protein fraction presenting such anti-inflammatory activity was purified and biochemically identified. The screening of the fraction responsible for such anti-inflammatory property was performed by evaluating the inhibition of carrageenan-induced paw edema in male Swiss mice. Biochemical analyses of the anti-inflammatory protein used chromatography, carbohydrates quantification of the protein sample, amino acids content analysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE. Total sugar quantification revealed 32% glycosylation of the protein fraction. Amino acid analysis of such fraction showed a peculiar pattern presenting 29% valine. SDS-PAGE revealed that the protein sample is pure and its molecular weight is about 40kDa. Intravenous injection of the isolated substance into mice significantly inhibited carrageenan-induced paw edema. The isolated glycoprotein decreased carrageenan-induced paw edema in a prostaglandin-dependent phase, suggesting an inhibitory effect of the isolated glycoprotein on prostaglandin synthesis.

Secreted Clusterin protein inhibits osteoblast differentiation of bone marrow mesenchymal stem cells by suppressing ERK1/2 signaling pathway

DEFF Research Database (Denmark)

Abdallah, Basem; Alzahrani, Abdullah M; Kassem, Moustapha

2018-01-01

Secreted Clusterin (sCLU, also known as Apolipoprotein J) is an anti-apoptotic glycoprotein involved in the regulation of cell proliferation, lipid transport, extracellular tissue remodeling and apoptosis. sCLU is expressed and secreted by mouse bone marrow-derived skeletal (stromal or mesenchyma...

TROPHOBLASTIC β1 – GLYCOPROTEIN SYNTHESIS IN SEROPOSITIVE PREGNANT WOMEN

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R. N. Bogdanovich

2005-01-01

Full Text Available Abstract. The level of trophoblastic β1 – glycoprotein (SP–1 was determined in the blood sera of 200 healthy pregnant women and 184 women with threatened abortions in term till 20 weeks of pregnancy. In group of women experiencing recurrent abortions in 38 % cases antibodies to chorionic gonadotropin, in 39,5 % cases antibodies to phospholipids, in 25,5 % – antibodies to tireoglobulin were revealed in significant amounts. In 20,65 % lupus anticoagulant was found. The majority of women in this group had changes in homeostasis. The presence of autoantibodies during pregnancy is the unfavourable factor in the development of placental insufficiency. This is proved by the decreased secretion of trophoblastic β1 – glycoprotein – a marker of the fetal part of placenta. (Med. Immunol., 2005, vol.7, № 1, pp. 85588

Secreted Progranulin Is a Homodimer and Is Not a Component of High Density Lipoproteins (HDL)*

Science.gov (United States)

Nguyen, Andrew D.; Nguyen, Thi A.; Cenik, Basar; Yu, Gang; Herz, Joachim; Walther, Tobias C.; Davidson, W. Sean; Farese, Robert V.

2013-01-01

Progranulin is a secreted glycoprotein, and the GRN gene is mutated in some cases of frontotemporal dementia. Progranulin has also been implicated in cell growth, wound healing, inflammation, and cancer. We investigated the molecular nature of secreted progranulin and provide evidence that progranulin exists as a homodimer. Although recombinant progranulin has a molecular mass of ∼85 kDa by SDS-PAGE, it elutes in fractions corresponding to ∼170–180 kDa by gel-filtration chromatography. Additionally, recombinant progranulin can be intermolecularly cross-linked, yielding a complex corresponding to a dimer (∼180 kDa), and progranulins containing different epitope tags physically interact. In plasma, progranulin similarly forms complexes of ∼180–190 kDa. Although progranulin partially co-fractionated with high density lipoproteins (HDL) by gel-filtration chromatography, we found no evidence that progranulin in mouse or human plasma is a component of HDL either by ultracentrifugation or by lipid binding assays. We conclude that circulating progranulin exists as a dimer and is not likely a component of HDL. PMID:23364791

Secreted progranulin is a homodimer and is not a component of high density lipoproteins (HDL).

Science.gov (United States)

Nguyen, Andrew D; Nguyen, Thi A; Cenik, Basar; Yu, Gang; Herz, Joachim; Walther, Tobias C; Davidson, W Sean; Farese, Robert V

2013-03-22

Progranulin is a secreted glycoprotein, and the GRN gene is mutated in some cases of frontotemporal dementia. Progranulin has also been implicated in cell growth, wound healing, inflammation, and cancer. We investigated the molecular nature of secreted progranulin and provide evidence that progranulin exists as a homodimer. Although recombinant progranulin has a molecular mass of ∼85 kDa by SDS-PAGE, it elutes in fractions corresponding to ∼170-180 kDa by gel-filtration chromatography. Additionally, recombinant progranulin can be intermolecularly cross-linked, yielding a complex corresponding to a dimer (∼180 kDa), and progranulins containing different epitope tags physically interact. In plasma, progranulin similarly forms complexes of ∼180-190 kDa. Although progranulin partially co-fractionated with high density lipoproteins (HDL) by gel-filtration chromatography, we found no evidence that progranulin in mouse or human plasma is a component of HDL either by ultracentrifugation or by lipid binding assays. We conclude that circulating progranulin exists as a dimer and is not likely a component of HDL.

Vaccination with the Secreted Glycoprotein G of Herpes Simplex Virus 2 Induces Protective Immunity after Genital Infection.

Science.gov (United States)

Önnheim, Karin; Ekblad, Maria; Görander, Staffan; Bergström, Tomas; Liljeqvist, Jan-Åke

2016-04-22

Herpes simplex virus 2 (HSV-2) infects the genital mucosa and establishes a life-long infection in sensory ganglia. After primary infection HSV-2 may reactivate causing recurrent genital ulcerations. HSV-2 infection is prevalent, and globally more than 400 million individuals are infected. As clinical trials have failed to show protection against HSV-2 infection, new vaccine candidates are warranted. The secreted glycoprotein G (sgG-2) of HSV-2 was evaluated as a prophylactic vaccine in mice using two different immunization and adjuvant protocols. The protocol with three intramuscular immunizations combining sgG-2 with cytosine-phosphate-guanine dinucleotide (CpG) motifs and alum induced almost complete protection from genital and systemic disease after intra-vaginal challenge with HSV-2. Robust immunoglobulin G (IgG) antibody titers were detected with no neutralization activity. Purified splenic CD4+ T cells proliferated and produced interferon-γ (IFN-γ) when re-stimulated with the antigen in vitro. sgG-2 + adjuvant intra-muscularly immunized mice showed a significant reduction of infectious HSV-2 and increased IFN-γ levels in vaginal washes. The HSV-2 DNA copy numbers were significantly reduced in dorsal root ganglia, spinal cord, and in serum at day six or day 21 post challenge. We show that a sgG-2 based vaccine is highly effective and can be considered as a novel candidate in the development of a prophylactic vaccine against HSV-2 infection.

Lipids in airway secretions

International Nuclear Information System (INIS)

Bhaskar, K.R.; DeFeudis O'Sullivan, D.; Opaskar-Hincman, H.; Reid, L.M.

1987-01-01

Lipids form a significant portion of airway mucus yet they have not received the same attention that epithelial glycoproteins have. We have analysed, by thin layer chromatography, lipids present in airway mucus under 'normal' and hypersecretory (pathological) conditions.The 'normals' included (1) bronchial lavage obtained from healthy human volunteers and from dogs and (2) secretions produced ''in vitro'' by human (bronchial) and canine (tracheal) explants. Hypersecretory mucus samples included (1) lavage from dogs made bronchitic by exposure to SO 2 , (2) bronchial aspirates from acute and chronic tracheostomy patients, (3) sputum from patients with cystic fibrosis and chronic bronchitis and (4) postmortem secretions from patients who died from sudden infant death syndrome (SIDS) or from status asthmaticus. Cholesterol was found to be the predominant lipid in 'normal' mucus with lesser amounts of phospholipids. No glycolipids were detected. In the hypersecretory mucus, in addition to neutral and phospholipids, glycolipids were present in appreciable amounts, often the predominant species, suggesting that these may be useful as markers of disease. Radioactive precursors 14 C acetate and 14 C palmitate were incorporated into lipids secreted ''in vitro'' by canine tracheal explants indicating that they are synthesised by the airway. (author)

Use of λgt11 to isolate genes for two pseudorabies virus glycoproteins with homology to herpes simplex virus and varicella-zoster virus glycoproteins

International Nuclear Information System (INIS)

Petrovskis, E.A.; Timmins, J.G.; Post, L.E.

1986-01-01

A library of pseudorabies virus (PRV) DNA fragments was constructed in the expression cloning vector λgt11. The library was screened with antisera which reacted with mixtures of PRV proteins to isolate recombinant bacteriophages expressing PRV proteins. By the nature of the λgt11 vector, the cloned proteins were expressed in Escherichia coli as β-galactosidase fusion proteins. The fusion proteins from 35 of these phages were purified and injected into mice to raise antisera. The antisera were screened by several different assays, including immunoprecipitation of [ 14 C]glucosamine-labeled PRV proteins. This method identified phages expressing three different PRV glycoproteins: the secreted glycoprotein, gX; gI; and a glycoprotein that had not been previously identified, which we designate gp63. The gp63 and gI genes map adjacent to each other in the small unique region of the PRV genome. The DNA sequence was determined for the region of the genome encoding gp63 and gI. It was found that gp63 has a region of homology with a herpes simplex virus type 1 (HSV-1) protein, encoded by US7, and also with varicella-zoster virus (VZV) gpIV. The gI protein sequence has a region of homology with HSV-1 gE and VZV gpI. It is concluded that PRV, HSV, and VZV all have a cluster of homologous glycoprotein genes in the small unique components of their genomes and that the organization of these genes is conserved

Requirements within the Ebola Viral Glycoprotein for Tetherin Antagonism

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Nathan H. Vande Burgt

2015-10-01

Full Text Available Tetherin is an interferon-induced, intrinsic cellular response factor that blocks release of numerous viruses, including Ebola virus, from infected cells. As with many viruses targeted by host factors, Ebola virus employs a tetherin antagonist, the viral glycoprotein (EboGP, to counteract restriction and promote virus release. Unlike other tetherin antagonists such as HIV-1 Vpu or KSHV K5, the features within EboGP needed to overcome tetherin are not well characterized. Here, we describe sequences within the EboGP ectodomain and membrane spanning domain (msd as necessary to relieve tetherin restriction of viral particle budding. Fusing the EboGP msd to a normally secreted form of the glycoprotein effectively promotes Ebola virus particle release. Cellular protein or lipid anchors could not substitute for the EboGP msd. The requirement for the EboGP msd was not specific for filovirus budding, as similar results were seen with HIV particles. Furthermore trafficking of chimeric proteins to budding sites did not correlate with an ability to counter tetherin. Additionally, we find that a glycoprotein construct, which mimics the cathepsin-activated species by proteolytic removal of the EboGP glycan cap and mucin domains, is unable to counteract tetherin. Combining these results suggests an important role for the EboGP glycan cap and msd in tetherin antagonism.

Structure of a trimeric variant of the Epstein-Barr virus glycoprotein B

Energy Technology Data Exchange (ETDEWEB)

Backovic, Marija [Northwestern Univ., Evanston, IL (United States); Longnecker, Richard [Northwestern Univ., Chicago, IL (United States); Jardetzky, Theodore S [Northwestern Univ., Evanston, IL (United States)

2009-03-16

Epstein-Barr virus (EBV) is a herpesvirus that is associated with development of malignancies of lymphoid tissue. EBV infections are life-long and occur in >90% of the population. Herpesviruses enter host cells in a process that involves fusion of viral and cellular membranes. The fusion apparatus is comprised of envelope glycoprotein B (gB) and a heterodimeric complex made of glycoproteins H and L. Glycoprotein B is the most conserved envelope glycoprotein in human herpesviruses, and the structure of gB from Herpes simplex virus 1 (HSV-1) is available. Here, we report the crystal structure of the secreted EBV gB ectodomain, which forms 16-nm long spike-like trimers, structurally homologous to the postfusion trimers of the fusion protein G of vesicular stomatitis virus (VSV). Comparative structural analyses of EBV gB and VSV G, which has been solved in its pre and postfusion states, shed light on gB residues that may be involved in conformational changes and membrane fusion. Also, the EBV gB structure reveals that, despite the high sequence conservation of gB in herpesviruses, the relative orientations of individual domains, the surface charge distributions, and the structural details of EBV gB differ from the HSV-1 protein, indicating regions and residues that may have important roles in virus-specific entry.

Determinants of foamy virus envelope glycoprotein mediated resistance to superinfection

International Nuclear Information System (INIS)

Berg, Angelika; Pietschmann, Thomas; Rethwilm, Axel; Lindemann, Dirk

2003-01-01

Little is known about the nature of foamy virus (FV) receptor molecules on target cells and their interaction with the viral glycoproteins. Similar to other viruses, cellular expression of the FV Env protein is sufficient to induce resistance to exogenous FV, a phenomenon called superinfection resistance (SIR). In this study we define determinants of the FV Env protein essential for mediating SIR. FV Env requires the extracellular domains of the SU and the TM subunits as well as membrane anchorage, efficient cell surface transport, and most probably correct subunit processing. This is in contrast to murine leukemia virus where secreted proteins comprising the receptor-binding domain in SU are sufficient to induce SIR. Furthermore, we demonstrate that cellular expression of the prototype FV envelope proteins induces SIR against pseudotypes with glycoproteins of other FV species, including of simian, feline, bovine, and equine origin. This implies that all of them use the same receptor molecules for viral entry

Defining glycoprotein cancer biomarkers by MS in conjunction with glycoprotein enrichment.

Science.gov (United States)

Song, Ehwang; Mechref, Yehia

2015-01-01

Protein glycosylation is an important and common post-translational modification. More than 50% of human proteins are believed to be glycosylated to modulate the functionality of proteins. Aberrant glycosylation has been correlated to several diseases, such as inflammatory skin diseases, diabetes mellitus, cardiovascular disorders, rheumatoid arthritis, Alzheimer's and prion diseases, and cancer. Many approved cancer biomarkers are glycoproteins which are not highly abundant proteins. Therefore, effective qualitative and quantitative assessment of glycoproteins entails enrichment methods. This chapter summarizes glycoprotein enrichment methods, including lectin affinity, immunoaffinity, hydrazide chemistry, hydrophilic interaction liquid chromatography, and click chemistry. The use of these enrichment approaches in assessing the qualitative and quantitative changes of glycoproteins in different types of cancers are presented and discussed. This chapter highlights the importance of glycoprotein enrichment techniques for the identification and characterization of new reliable cancer biomarkers.

Prediction of conserved sites and domains in glycoproteins B, C and D of herpes viruses.

Science.gov (United States)

Rasheed, Muhammad Asif; Ansari, Abdur Rahman; Ihsan, Awais; Navid, Muhammad Tariq; Ur-Rehman, Shahid; Raza, Sohail

2018-03-01

Glycoprotein B (gB), C (gC) and D (gD) of herpes simplex virus are implicated in virus adsorption and penetration. The gB, gC and gD are glycoproteins for different processes of virus binding and attachment to the host cells. Moreover, their expression is necessary and sufficient to induce cell fusion in the absence of other glycoproteins. Egress of herpes simplex virus (HSV) and other herpes viruses from cells involves extensive modification of cellular membranes and sequential envelopment, de-envelopment and re-envelopment steps. Viral glycoproteins are important in these processes, and frequently two or more glycoproteins can largely suffice in any step. Hence, we target the 3 important glycoproteins (B, C and D) of eight different herpes viruses of different species. These species include human (HSV1 and 2), bovine (BHV1), equine (EHV1 and 4), chicken (ILT1 and MDV2) and pig (PRV1). By applying different bioinformatics tools, we highlighted the conserved sites in these glycoproteins which might be most significant regarding attachment and infection of the viruses. Moreover the conserved domains in these glycoproteins are also highlighted. From this study, we will able to analyze the role of different viral glycoproteins of different species during herpes virus adsorption and penetration. Moreover, this study will help to construct the antivirals that target the glycoproteins of different herpes viruses. Copyright © 2018 Elsevier Ltd. All rights reserved.

Apparent inhibition of β-fructosidase secretion by tunicamycin may be explained by breakdown of the unglycosylated protein during secretion

International Nuclear Information System (INIS)

Faye, L.; Chrispeels, M.J.

1989-01-01

Suspension-cultured carrot (Daucus carota) cells synthesize and secrete β-fructosidase, a glycoprotein with asparagine-linked glycans. Treatment of the cells with tunicamycin completely inhibits the apparent secretion of β-fructosidase as measured by the accumulation of the 35 S-labelled protein in the cell wall or the culture medium. In the past, such a result has been interpreted as an inhibition of secretion by tunicamycin, but we suggest another explanation based on the following results. In the presence of tunicamycin, unglycosylated β-fructosidase is synthesized and is associated with an endoplasmic-reticulum-rich microsomal fraction. Pulse-chase experiments show that the unglycosylated β-fructosidase does not remain in the cells and appears to be secreted in the same way as glycosylated β-fructosidase; however, no radioactive, unglycosylated β-fructosidase accumulates extracellularly (cell wall or medium). Protoplasts obtained from carrot cells secrete β-fructosidase protein and activity, and treatment of the protoplasts with tunicamycin results in the synthesis of unglycosylated β-fructosidase. In the presence of tunicamycin, there is no accumulation of β-fructosidase activity or unglycosylated β-fructosidase polypeptide in the protoplast incubation medium. These results are consistent with the interpretation that the glycans of β-fructosidase are necessary for its stability, and that in these suspension-cultured cells, the unglycosylated enzyme is degraded during the last stage(s) of secretion, or immediately after its arrival in the wall

Glycoprotein on cell surfaces

International Nuclear Information System (INIS)

Muramatsu, T.

1975-01-01

There are conjugated polysaccharides in cell membranes and outside of animal cells, and they play important role in the control of cell behavior. In this paper, the studies on the glycoprotein on cell surfaces are reported. It was found that the glycoprotein on cell surfaces have both N-glycoside type and O-glycoside type saccharic chains. Therefore it can be concluded that the basic structure of the saccharic chains in the glycoprotein on cell surfaces is similar to that of blood serum and body fluid. The main glycoprotein in the membranes of red blood corpuscles has been studied most in detail, and it also has both types of saccharic chains. The glycoprotein in liver cell membranes was found to have only the saccharic chains of acid type and to be in different pattern from that in endoplasmic reticula and nuclear membranes, which also has the saccharic chains of neutral type. The structure of the saccharic chains of H-2 antigen, i.e. the peculiar glycoprotein on the surfaces of lymph system cells, has been studied, and it is similar to the saccharic chains of glycoprotein in blood serum. The saccharic chain structures of H-2 antigen and TL antigen are different. TL, H-2 (D), Lna and H-2 (K) are the glycoprotein on cell surfaces, and are independent molecules. The analysis of the saccharic chain patterns on cell surfaces was carried out, and it was shown that the acid type saccharic chains were similar to those of ordinary glycoprotein, because the enzyme of pneumococci hydrolyzed most of the acid type saccharic chains. The change of the saccharic chain patterns of glycoprotein on cell surfaces owing to canceration and multiplication is complex matter. (Kako, I.)

Utilization by the isolated perfused rat liver of N-acetyl-D-(1-/sup 14/C)galactosamine and N-brace/sup 3/H)-acetyl-D-galactosamine for the biosynthesis of glycoproteins

Energy Technology Data Exchange (ETDEWEB)

MacNicoll, A D; Wusteman, F S; Powell, G M; Curtis, C G [University Coll., Cardiff (UK)

1978-08-15

The isolated perfused rat liver system has been used to monitor the utilization of N-(/sup 3/H)acetyl-D-galactosamine and N-acetyl-D-(1-/sup 14/C)galactosamine for the biosynthesis of radiolabeled glycoproteins, which are subsequently secreted into the plasma. Both radiolabels appear in a number of different glycoproteins, predominantly as sialic acid and N-acetylglucosamine. The ratio of labelled sialic acid to labelled N-acetylglucosamine varies for different glycoproteins, but the bulk of N-acetyl-D-galactosamine is incorporated without deacetylation.

A catalogue of human secreted proteins and its implications

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Shivakumar Keerthikumar

2016-11-01

Full Text Available Under both normal and pathological conditions, cells secrete variety of proteins through classical and non-classical secretory pathways into the extracellular space. Majority of these proteins represent pathophysiology of the cell from which it is secreted. Recently, though more than 92% of the protein coding genes has been mapped by human proteome map project, but number of those proteins that constitutes secretome of the cell still remains elusive. Secreted proteins or the secretome can be accessible in bodily fluids and hence are considered as potential biomarkers to discriminate between healthy and diseased individuals. In order to facilitate the biomarker discovery and to further aid clinicians and scientists working in these arenas, we have compiled and catalogued secreted proteins from the human proteome using integrated bioinformatics approach. In this study, nearly 14% of the human proteome is likely to be secreted through classical and non-classical secretory pathways. Out of which, ~38% of these secreted proteins were found in extracellular vesicles including exosomes and shedding microvesicles. Among these secreted proteins, 94% were detected in human bodily fluids including blood, plasma, serum, saliva, semen, tear and urine. We anticipate that this high confidence list of secreted proteins could serve as a compendium of candidate biomarkers. In addition, the catalogue may provide functional insights in understanding the molecular mechanisms involved in various physiological and pathophysiological conditions of the cell.

Convergent evolution of pregnancy-specific glycoproteins in human and horse.

Science.gov (United States)

Aleksic, Denis; Blaschke, Lisa; Mißbach, Sophie; Hänske, Jana; Weiß, Wiebke; Handler, Johannes; Zimmermann, Wolfgang; Cabrera-Sharp, Victoria; Read, Jordan E; de Mestre, Amanda M; O'Riordan, Ronan; Moore, Tom; Kammerer, Robert

2016-09-01

Pregnancy-specific glycoproteins (PSGs) are members of the carcinoembryonic antigen cell adhesion molecule (CEACAM) family that are secreted by trophoblast cells. PSGs may modulate immune, angiogenic and platelet responses during pregnancy. Until now, PSGs are only found in species that have a highly invasive (hemochorial) placentation including humans, mice and rats. Surprisingly, analyzing the CEACAM gene family of the horse, which has a non-invasive epitheliochorial placenta, with the exception of the transient endometrial cups, we identified equine CEACAM family members that seem to be related to PSGs of rodents and primates. We identified seven genes that encode secreted PSG-like CEACAMs Phylogenetic analyses indicate that they evolved independently from an equine CEACAM1-like ancestor rather than from a common PSG-like ancestor with rodents and primates. Significantly, expression of PSG-like genes (CEACAM44, CEACAM48, CEACAM49 and CEACAM55) was found in non-invasive as well as invasive trophoblast cells such as purified chorionic girdle cells and endometrial cup cells. Chorionic girdle cells are highly invasive trophoblast cells that invade the endometrium of the mare where they form endometrial cups and are in close contact with maternal immune cells. Therefore, the microenvironment of invasive equine trophoblast cells has striking similarities to the microenvironment of trophoblast cells in hemochorial placentas, suggesting that equine PSG-like CEACAMs and rodent and primate PSGs have undergone convergent evolution. This is supported by our finding that equine PSG-like CEACAM49 exhibits similar activity to certain rodent and human PSGs in a functional assay of platelet-fibrinogen binding. Our results have implications for understanding the evolution of PSGs and their functions in maternal-fetal interactions. © 2016 Society for Reproduction and Fertility.

Staphylococcal superantigen-like 5 activates platelets and supports platelet adhesion under flow conditions, which involves glycoprotein Ib alpha and alpha(IIb)beta(3)

NARCIS (Netherlands)

De Haas, C. J. C.; Weeterings, C.; Vughs, M. M.; De Groot, P. G.; Van Strijp, J. A.; Lisman, T.

2009-01-01

Objectives: Staphylococcal superantigen-like 5 (SSL5) is an exoprotein secreted by Staphylococcus aureus that has been shown to inhibit neutrophil rolling over activated endothelial cells via a direct interaction with P-selectin glycoprotein ligand 1 (PSGL-1). Methods and Results: When purified

Differential staining of Western blots of human secreted glycoproteins from serum, milk, saliva, and seminal fluid using lectins displaying diverse sugar specificities.

Science.gov (United States)

Gilboa-Garber, Nechama; Lerrer, Batya; Lesman-Movshovich, Efrat; Dgani, Orly

2005-12-01

Human milk, serum, saliva, and seminal fluid glycoproteins (gps) nourish and protect newborn and adult tissues. Their saccharides, which resemble cell membrane components, may block pathogen adhesion and infection. In the present study, they were examined by a battery of lectins from plants, animals, and bacteria, using hemagglutination inhibition and Western blot analyses. The lectins included galactophilic ones from Aplysia gonad, Erythrina corallodendron, Maclura pomifera (MPL), peanut, and Pseudomonas aeruginosa (PA-IL); fucose-binding lectins from Pseudomonas aeruginosa (PA-IIL), Ralstonia solanacearum (RSL), and Ulex europaeus (UEA-I), and mannose/glucose-binding Con A. The results demonstrated the chosen lectin efficiency for differential analysis of human secreted gps as compared to CBB staining. They unveiled the diversity of these body fluid gp glycans (those of the milk and seminal fluid being highest): the milk gps interacted most strongly with PA-IIL, followed by RSL; the saliva gps with RSL, followed by PA-IIL and MPL; the serum gps with Con A and MPL, followed by PA-IIL and RSL, and the seminal plasma gps with RSL and MPL, followed by UEA-I and PA-IIL. The potential usage of these lectins as probes for scientific, industrial, and medical purposes, and for quality control of the desired gps is clearly indicated.

Recent Progress in Electrochemical Biosensors for Glycoproteins

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Uichi Akiba

2016-12-01

Full Text Available This review provides an overview of recent progress in the development of electrochemical biosensors for glycoproteins. Electrochemical glycoprotein sensors are constructed by combining metal and carbon electrodes with glycoprotein-selective binding elements including antibodies, lectin, phenylboronic acid and molecularly imprinted polymers. A recent trend in the preparation of glycoprotein sensors is the successful use of nanomaterials such as graphene, carbon nanotube, and metal nanoparticles. These nanomaterials are extremely useful for improving the sensitivity of glycoprotein sensors. This review focuses mainly on the protocols for the preparation of glycoprotein sensors and the materials used. Recent improvements in glycoprotein sensors are discussed by grouping the sensors into several categories based on the materials used as recognition elements.

Progranulin, a glycoprotein deficient in frontotemporal dementia, is a novel substrate of several protein disulfide isomerase family proteins.

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Sandra Almeida

Full Text Available The reduced production or activity of the cysteine-rich glycoprotein progranulin is responsible for about 20% of cases of familial frontotemporal dementia. However, little is known about the molecular mechanisms that govern the level and secretion of progranulin. Here we show that progranulin is expressed in mouse cortical neurons and more prominently in mouse microglia in culture and is abundant in the endoplasmic reticulum (ER and Golgi. Using chemical crosslinking, immunoprecipitation, and mass spectrometry, we found that progranulin is bound to a network of ER Ca(2+-binding chaperones including BiP, calreticulin, GRP94, and four members of the protein disulfide isomerase (PDI family. Loss of ERp57 inhibits progranulin secretion. Thus, progranulin is a novel substrate of several PDI family proteins and modulation of the ER chaperone network may be a therapeutic target for controlling progranulin secretion.

Development of glycoprotein capture-based label-free method for the high-throughput screening of differential glycoproteins in hepatocellular carcinoma.

Science.gov (United States)

Chen, Rui; Tan, Yexiong; Wang, Min; Wang, Fangjun; Yao, Zhenzhen; Dong, Liwei; Ye, Mingliang; Wang, Hongyang; Zou, Hanfa

2011-07-01

A robust, reproducible, and high throughput method was developed for the relative quantitative analysis of glycoprotein abundances in human serum. Instead of quantifying glycoproteins by glycopeptides in conventional quantitative glycoproteomics, glycoproteins were quantified by nonglycosylated peptides derived from the glycoprotein digest, which consists of the capture of glycoproteins in serum samples and the release of nonglycopeptides by trypsin digestion of captured glycoproteins followed by two-dimensional liquid chromatography-tandem MS analysis of released peptides. Protein quantification was achieved by comparing the spectrum counts of identified nonglycosylated peptides of glycoproteins between different samples. This method was demonstrated to have almost the same specificity and sensitivity in glycoproteins quantification as capture at glycopeptides level. The differential abundance of proteins present at as low as nanogram per milliliter levels was quantified with high confidence. The established method was applied to the analysis of human serum samples from healthy people and patients with hepatocellular carcinoma (HCC) to screen differential glycoproteins in HCC. Thirty eight glycoproteins were found with substantial concentration changes between normal and HCC serum samples, including α-fetoprotein, the only clinically used marker for HCC diagnosis. The abundance changes of three glycoproteins, i.e. galectin-3 binding protein, insulin-like growth factor binding protein 3, and thrombospondin 1, which were associated with the development of HCC, were further confirmed by enzyme-linked immunosorbent assay. In conclusion, the developed method was an effective approach to quantitatively analyze glycoproteins in human serum and could be further applied in the biomarker discovery for HCC and other cancers.

Secreted herpes simplex virus-2 glycoprotein G modifies NGF-TrkA signaling to attract free nerve endings to the site of infection.

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Jorge Rubén Cabrera

2015-01-01

Full Text Available Herpes simplex virus type 1 (HSV-1 and HSV-2 are highly prevalent viruses that cause a variety of diseases, from cold sores to encephalitis. Both viruses establish latency in peripheral neurons but the molecular mechanisms facilitating the infection of neurons are not fully understood. Using surface plasmon resonance and crosslinking assays, we show that glycoprotein G (gG from HSV-2, known to modulate immune mediators (chemokines, also interacts with neurotrophic factors, with high affinity. In our experimental model, HSV-2 secreted gG (SgG2 increases nerve growth factor (NGF-dependent axonal growth of sympathetic neurons ex vivo, and modifies tropomyosin related kinase (TrkA-mediated signaling. SgG2 alters TrkA recruitment to lipid rafts and decreases TrkA internalization. We could show, with microfluidic devices, that SgG2 reduced NGF-induced TrkA retrograde transport. In vivo, both HSV-2 infection and SgG2 expression in mouse hindpaw epidermis enhance axonal growth modifying the termination zone of the NGF-dependent peptidergic free nerve endings. This constitutes, to our knowledge, the discovery of the first viral protein that modulates neurotrophins, an activity that may facilitate HSV-2 infection of neurons. This dual function of the chemokine-binding protein SgG2 uncovers a novel strategy developed by HSV-2 to modulate factors from both the immune and nervous systems.

Structure of the Membrane Anchor of Pestivirus Glycoprotein Erns, a Long Tilted Amphipathic Helix

Science.gov (United States)

Aberle, Daniel; Muhle-Goll, Claudia; Bürck, Jochen; Wolf, Moritz; Reißer, Sabine; Luy, Burkhard; Wenzel, Wolfgang; Ulrich, Anne S.; Meyers, Gregor

2014-01-01

Erns is an essential virion glycoprotein with RNase activity that suppresses host cellular innate immune responses upon being partially secreted from the infected cells. Its unusual C-terminus plays multiple roles, as the amphiphilic helix acts as a membrane anchor, as a signal peptidase cleavage site, and as a retention/secretion signal. We analyzed the structure and membrane binding properties of this sequence to gain a better understanding of the underlying mechanisms. CD spectroscopy in different setups, as well as Monte Carlo and molecular dynamics simulations confirmed the helical folding and showed that the helix is accommodated in the amphiphilic region of the lipid bilayer with a slight tilt rather than lying parallel to the surface. This model was confirmed by NMR analyses that also identified a central stretch of 15 residues within the helix that is fully shielded from the aqueous layer, which is C-terminally followed by a putative hairpin structure. These findings explain the strong membrane binding of the protein and provide clues to establishing the Erns membrane contact, processing and secretion. PMID:24586172

Evaluating the Effects of Cytomegalovirus Glycoprotein B on the Maturation and Function of Monocyte-derived dendritic cells

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Afsson shariat

2015-11-01

Full Text Available Background & Objectives: Interaction of cytomegalovirus glycoprotein B with toll-like receptors of dendritic cells leads to early signaling and innate immune responses. The aim of this study is to evaluate the effects of cytomegalovirus glycoprotein B on the maturation and function of monocyte-derived dendritic cells in treated groups in comparison with control groups. Materials & Methods: Blood samples were taken from 5 healthy volunteers. Following the generation of monocyte-derived dendritic cells on the fifth day of cell culture, half of the immature dendritic cells were treated with cytomegalovirus glycoprotein B, and the rest of them were induced to mature dendritic untreated cells and were used as the control group. The maturation and function of dendritic cells were evaluated in these two groups. Results: The gene expression level of toll-like receptor-4 significantly increased in the group treated with glycoprotein B (p < 0.05, whereas there were no significant differences in the expression rates of CD83, CD86, CD1a, and HLA-DR and the secretion of IL-23 from monocyte-derived dendritic cells between the treated groups and the controls. Conclusion: The increase in the gene expression of toll-like receptor-4 in monocyte-derived dendritic cells treated with cytomegalovirus glycoprotein B showed that cell contact is required to elicit cellular antiviral response and toll-like receptor activation. Thus, it is critical to recognize the viral and cellular determinants of the immune system in order to develop new therapeutic strategies against cytomegalovirus.

Cell wall O-glycoproteins and N-glycoproteins: biosynthesis and some functional aspects.

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Eric eNguema-Ona

2014-10-01

Full Text Available Cell wall O-glycoproteins and N-glycoproteins are two types of glycomolecules whose glycans are structurally complex. They are both assembled and modified within the endomembrane system, i.e., the endoplasmic reticulum (ER and the Golgi apparatus, before their transport to their final locations within or outside the cell. In contrast to extensin, the O-glycan chains of arabinogalactan proteins are highly heterogeneous consisting mostly of (i a short oligo-arabinoside chain of three to four residues, and (ii a larger -1,3-linked galactan backbone with -1,6-linked side chains containing galactose, arabinose and, often, fucose, rhamnose or glucuronic acid. The fine structure of arabinogalactan chains varies between, and within plant species, and is important for the functional activities of the glycoproteins. With regards to N-glycans, ER-synthesizing events are highly conserved in all eukaryotes studied so far since they are essential for efficient protein folding. In contrast, evolutionary adaptation of N-glycan processing in the Golgi apparatus has given rise to a variety of organism-specific complex structures. Therefore, plant complex-type N-glycans contain specific glyco-epitopes such as core 1,2-xylose, core 1,3-fucose residues and Lewisa substitutions on the terminal position of the antenna. Like O-glycans, N-glycans of proteins are essential for their stability and function. Mutants affected in the glycan metabolic pathways have provided valuable information on the role of N-/O-glycoproteins in the control of growth, morphogenesis and adaptation to biotic and abiotic stresses. With regards to O-glycoproteins only extensin and arabinogalactan proteins are considered herein. The biosynthesis of these glycoproteins and functional aspects are presented and discussed in this review.

Lipid Binding of the Amphipathic Helix Serving as Membrane Anchor of Pestivirus Glycoprotein Erns.

Science.gov (United States)

Aberle, Daniel; Oetter, Kay-Marcus; Meyers, Gregor

2015-01-01

Pestiviruses express a peculiar protein named Erns representing envelope glycoprotein and RNase, which is important for control of the innate immune response and persistent infection. The latter functions are connected with secretion of a certain amount of Erns from the infected cell. Retention/secretion of Erns is most likely controlled by its unusual membrane anchor, a long amphipathic helix attached in plane to the membrane. Here we present results of experiments conducted with a lipid vesicle sedimentation assay able to separate lipid-bound from unbound protein dissolved in the water phase. Using this technique we show that a protein composed of tag sequences and the carboxyterminal 65 residues of Erns binds specifically to membrane vesicles with a clear preference for compositions containing negatively charged lipids. Mutations disturbing the helical folding and/or amphipathic character of the anchor as well as diverse truncations and exchange of amino acids important for intracellular retention of Erns had no or only small effects on the proteins membrane binding. This result contrasts the dramatically increased secretion rates observed for Erns proteins with equivalent mutations within cells. Accordingly, the ratio of secreted versus cell retained Erns is not determined by the lipid affinity of the membrane anchor.

Lipid Binding of the Amphipathic Helix Serving as Membrane Anchor of Pestivirus Glycoprotein Erns.

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Daniel Aberle

Full Text Available Pestiviruses express a peculiar protein named Erns representing envelope glycoprotein and RNase, which is important for control of the innate immune response and persistent infection. The latter functions are connected with secretion of a certain amount of Erns from the infected cell. Retention/secretion of Erns is most likely controlled by its unusual membrane anchor, a long amphipathic helix attached in plane to the membrane. Here we present results of experiments conducted with a lipid vesicle sedimentation assay able to separate lipid-bound from unbound protein dissolved in the water phase. Using this technique we show that a protein composed of tag sequences and the carboxyterminal 65 residues of Erns binds specifically to membrane vesicles with a clear preference for compositions containing negatively charged lipids. Mutations disturbing the helical folding and/or amphipathic character of the anchor as well as diverse truncations and exchange of amino acids important for intracellular retention of Erns had no or only small effects on the proteins membrane binding. This result contrasts the dramatically increased secretion rates observed for Erns proteins with equivalent mutations within cells. Accordingly, the ratio of secreted versus cell retained Erns is not determined by the lipid affinity of the membrane anchor.

The pestivirus Erns glycoprotein interacts with E2 in both infected cells and mature virions

International Nuclear Information System (INIS)

Lazar, Catalin; Zitzmann, Nicole; Dwek, Raymond A.; Branza-Nichita, Norica

2003-01-01

E rns is a pestivirus envelope glycoprotein indispensable for virus attachment and infection of target cells. Unlike the other two envelope proteins E1 and E2, E rns lacks a transmembrane domain and a vast quantity is secreted into the medium of infected cells. The protein is also present in fractions of pure pestivirus virions, raising the important and intriguing question regarding the mechanism of its attachment to the pestivirus envelope. In this study a direct interaction between E rns and E2 glycoproteins was demonstrated in both pestivirus-infected cells and mature virions. By co- and sequential immunoprecipitation we showed that an E rns -E2 heterodimer is assembled very early after translation of the viral polyprotein and before its processing is completed. Our results suggest that E rns is attached to the pestivirus envelope via a direct interaction with E2 and explain the role of E rns in the initial virus-target cell interaction

Glycoprotein hormone α subunit secretion by pituitary adenomas: influence of external irradiation

International Nuclear Information System (INIS)

Macfarlane, I.A.; Beardwell, C.G.; Shalet, S.M.; Darbyshire, P.J.; Hayward, E.; Sutton, M.L.

1980-01-01

In ninety-nine patients with pituitary adenomas, forty-six with acromegaly, the serum level of the glycoprotein hormone α subunit was elevated in eighteen cases. Thirteen of these were acromegalic and one had an FSH-producing tumour. Alpha levels varied little during the day, from one day to the next and over a 6 month period. In twenty-five patients with a variety of other hypothalamic-pituitary disorders examined, one patient with a craniopharyngioma had a mildly elevated α level. External pituitary irradiation was followed by an acute and often transient fall in α level in several of these patients. Of the fifty-four patients with pituitary adenomas who had received external irradiation before testing, only five had elevated α subunit levels compared with thirteen patients of the forty-five who had not been irradiated. This difference in incidence of elevated α level was statistically significant (P<0.025). It is concluded that external irradiation may reduce α subunit level chronically in many patients with pituitary adenoma. (author)

Structure of the membrane anchor of pestivirus glycoprotein E(rns, a long tilted amphipathic helix.

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Daniel Aberle

2014-02-01

Full Text Available E(rns is an essential virion glycoprotein with RNase activity that suppresses host cellular innate immune responses upon being partially secreted from the infected cells. Its unusual C-terminus plays multiple roles, as the amphiphilic helix acts as a membrane anchor, as a signal peptidase cleavage site, and as a retention/secretion signal. We analyzed the structure and membrane binding properties of this sequence to gain a better understanding of the underlying mechanisms. CD spectroscopy in different setups, as well as Monte Carlo and molecular dynamics simulations confirmed the helical folding and showed that the helix is accommodated in the amphiphilic region of the lipid bilayer with a slight tilt rather than lying parallel to the surface. This model was confirmed by NMR analyses that also identified a central stretch of 15 residues within the helix that is fully shielded from the aqueous layer, which is C-terminally followed by a putative hairpin structure. These findings explain the strong membrane binding of the protein and provide clues to establishing the E(rns membrane contact, processing and secretion.

Structure of the membrane anchor of pestivirus glycoprotein E(rns), a long tilted amphipathic helix.

Science.gov (United States)

Aberle, Daniel; Muhle-Goll, Claudia; Bürck, Jochen; Wolf, Moritz; Reißer, Sabine; Luy, Burkhard; Wenzel, Wolfgang; Ulrich, Anne S; Meyers, Gregor

2014-02-01

E(rns) is an essential virion glycoprotein with RNase activity that suppresses host cellular innate immune responses upon being partially secreted from the infected cells. Its unusual C-terminus plays multiple roles, as the amphiphilic helix acts as a membrane anchor, as a signal peptidase cleavage site, and as a retention/secretion signal. We analyzed the structure and membrane binding properties of this sequence to gain a better understanding of the underlying mechanisms. CD spectroscopy in different setups, as well as Monte Carlo and molecular dynamics simulations confirmed the helical folding and showed that the helix is accommodated in the amphiphilic region of the lipid bilayer with a slight tilt rather than lying parallel to the surface. This model was confirmed by NMR analyses that also identified a central stretch of 15 residues within the helix that is fully shielded from the aqueous layer, which is C-terminally followed by a putative hairpin structure. These findings explain the strong membrane binding of the protein and provide clues to establishing the E(rns) membrane contact, processing and secretion.

Progranulin, a Glycoprotein Deficient in Frontotemporal Dementia, Is a Novel Substrate of Several Protein Disulfide Isomerase Family Proteins

OpenAIRE

Almeida, Sandra; Zhou, Lijuan; Gao, Fen-Biao

2011-01-01

The reduced production or activity of the cysteine-rich glycoprotein progranulin is responsible for about 20% of cases of familial frontotemporal dementia. However, little is known about the molecular mechanisms that govern the level and secretion of progranulin. Here we show that progranulin is expressed in mouse cortical neurons and more prominently in mouse microglia in culture and is abundant in the endoplasmic reticulum (ER) and Golgi. Using chemical crosslinking, immunoprecipitation, an...

The herpes simplex virus 1-encoded envelope glycoprotein B activates NF-κB through the Toll-like receptor 2 and MyD88/TRAF6-dependent signaling pathway.

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Mingsheng Cai

Full Text Available The innate immune response plays a critical role in the host defense against invading pathogens, and TLR2, a member of the Toll-like receptor (TLR family, has been implicated in the immune response and initiation of inflammatory cytokine secretion against several human viruses. Previous studies have demonstrated that infectious and ultraviolet-inactivated herpes simplex virus 1 (HSV-1 virions lead to the activation of nuclear factor kappa B (NF-κB and secretion of proinflammatory cytokines via TLR2. However, except for the envelope glycoprotein gH and gL, whether there are other determinants of HSV-1 responsible for TLR2 mediated biological effects is not known yet. Here, we demonstrated that the HSV-1-encoded envelope glycoprotein gB displays as molecular target recognized by TLR2. gB coimmunoprecipitated with TLR2, TLR1 and TLR6 in transfected and infected human embryonic kidney (HEK 293T cells. Treatment of TLR2-transfected HEK293T (HEK293T-TLR2 cells with purified gB results in the activation of NF-κB reporter, and this activation requires the recruitment of the adaptor molecules myeloid differentiation primary-response protein 88 (MyD88 and tumor necrosis factor receptor-associated factor 6 (TRAF6 but not CD14. Furthermore, activation of NF-κB was abrogated by anti-gB and anti-TLR2 blocking antibodies. In addition, the expression of interleukin-8 induced by gB was abrogated by the treatment of the human monocytic cell line THP-1 with anti-TLR2 blocking antibody or by the incubation of gB with anti-gB antibody. Taken together, these results indicate the importance and potency of HSV-1 gB as one of pathogen-associated molecular patterns (PAMPs molecule recognized by TLR2 with immediate kinetics.

Dimers of beta 2-glycoprotein I mimic the in vitro effects of beta 2-glycoprotein I-anti-beta 2-glycoprotein I antibody complexes

NARCIS (Netherlands)

Lutters, B. C.; Meijers, J. C.; Derksen, R. H.; Arnout, J.; de Groot, P. G.

2001-01-01

Anti-beta(2)-glycoprotein I antibodies are thought to cause lupus anticoagulant activity by forming bivalent complexes with beta(2)-glycoprotein I (beta(2)GPI). To test this hypothesis, chimeric fusion proteins were constructed of the dimerization domain (apple 4) of factor XI and beta(2)GPI. Both a

Shedding of soluble glycoprotein 1 detected during acute Lassa virus infection in human subjects.

Science.gov (United States)

Branco, Luis M; Grove, Jessica N; Moses, Lina M; Goba, Augustine; Fullah, Mohammed; Momoh, Mambu; Schoepp, Randal J; Bausch, Daniel G; Garry, Robert F

2010-11-09

Lassa hemorrhagic fever (LHF) is a neglected tropical disease with significant impact on the health care system, society, and economy of Western and Central African nations where it is endemic. With a high rate of infection that may lead to morbidity and mortality, understanding how the virus interacts with the host's immune system is of great importance for generating vaccines and therapeutics. Previous work by our group identified a soluble isoform of the Lassa virus (LASV) GP1 (sGP1) in vitro resulting from the expression of the glycoprotein complex (GPC) gene [1, 2]. Though no work has directly been done to demonstrate the function of this soluble isoform in arenaviral infections, evidence points to immunomodulatory effects against the host's immune system mediated by a secreted glycoprotein component in filoviruses, another class of hemorrhagic fever-causing viruses. A significant fraction of shed glycoprotein isoforms during viral infection and biogenesis may attenuate the host's inflammatory response, thereby enhancing viral replication and tissue damage. Such shed glycoprotein mediated effects were previously reported for Ebola virus (EBOV), a filovirus that also causes hemorrhagic fever with nearly 90 percent fatality rates [3 - 5]. The identification of an analogous phenomenon in vivo could establish a new correlate of LHF infection leading to the development of sensitive diagnostics targeting the earliest molecular events of the disease. Additionally, the reversal of potentially untoward immunomodulatory functions mediated by sGP1 could potentiate the development of novel therapeutic intervention. To this end, we investigated the presence of sGP1 in the serum of suspected LASV patients admitted to the Kenema Government Hospital (KGH) Lassa Fever Ward (LFW), in Kenema, Sierra Leone that tested positive for viral antigen or displayed classical signs of Lassa fever. It is reasonable to expect that a narrow window exists for detection of sGP1 as the sole

A SNX3-dependent retromer pathway mediates retrograde transport of the Wnt sorting receptor Wntless and is required for Wnt secretion

NARCIS (Netherlands)

Harterink, M.; Port, F.; Lorenowicz, M.J.; McGough, I.J.; Silhankova, M.; Betist, M.C.; van Weering, J.R.; van Heesbeen, R.G.; Middelkoop, T.C.; Basler, K.; Cullen, P.J.; Korswagen, H.C.

2011-01-01

Wnt proteins are lipid-modified glycoproteins that play a central role in development, adult tissue homeostasis and disease. Secretion of Wnt proteins is mediated by the Wnt-binding protein Wntless (Wls), which transports Wnt from the Golgi network to the cell surface for release. It has recently

Glycosylation in secreted proteins from yeast Kluyveromyces lactis

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Santos, A.V.; Passos, F.M.L. [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Microbiologia. Lab. de Fisiologia de Microrganismos; Azevedo, B.R.; Pimenta, A.M.C.; Santoro, M.M. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Bioquimica e Imunologia. Lab. de Enzimologia e Fisico-Quimica de Proteina

2008-07-01

Full text: The nutritional status of a cell culture affects either the expression or the traffic of a number of proteins. The identification of the physiological conditions which favor protein secretion has important biotechnological consequences in designing systems for recombinant extracellular protein industrial production. Yeast Kluyvromyces lactis has been cultured in a continuous stirring tank bioreactor (CSTR) under nitrogen limitation at growth rates (0.03 h{sup -1} and 0.09 h{sup -1}) close to either exponential or stationary batch growth phases, respectively the objective was to investigate the extracellular glycoproteins at these two level of nitrogen limitation. Proteins from free cell extracts were separated by gradient SDS-PAGE (5-15%) and two-dimensional chromatography, and were analyzed by mass spectrometry (MALDI-TOF-TOF-MS). In SDS-PAGE analysis, differences in extracellular proteome were visualized: different proteins profiles at these two growth rates. The 0.09 h-1 growth rate showed larger number of bands using colloidal Coma ssie Blue staining. Different bands were detected at these two growth rates when the PAS assay for glycoprotein detection in polyacrylamide gel was used. The two-dimensional chromatogram profiles were comparatively distinguished between the 0.03 h{sup -1} and 0.09 h{sup -1} growth rate samples. Protein peaks from the second dimension, were subjected to mass spectrometry. The mass spectrums visualized showed glycosylated proteins with N-acetylglucosamine molecules and 8, 9 or 15 hexoses molecules. Comparisons between the proteins averaged mass values with the deduced proteins masses from K. lactis secreted proteins database indicated possible post-translational modifications, such as post-translational proteolysis, acetylation, deamidation and myristoylation.

Glycosylation in secreted proteins from yeast Kluyveromyces lactis

International Nuclear Information System (INIS)

Santos, A.V.; Passos, F.M.L.; Azevedo, B.R.; Pimenta, A.M.C.; Santoro, M.M.

2008-01-01

Full text: The nutritional status of a cell culture affects either the expression or the traffic of a number of proteins. The identification of the physiological conditions which favor protein secretion has important biotechnological consequences in designing systems for recombinant extracellular protein industrial production. Yeast Kluyvromyces lactis has been cultured in a continuous stirring tank bioreactor (CSTR) under nitrogen limitation at growth rates (0.03 h -1 and 0.09 h -1 ) close to either exponential or stationary batch growth phases, respectively the objective was to investigate the extracellular glycoproteins at these two level of nitrogen limitation. Proteins from free cell extracts were separated by gradient SDS-PAGE (5-15%) and two-dimensional chromatography, and were analyzed by mass spectrometry (MALDI-TOF-TOF-MS). In SDS-PAGE analysis, differences in extracellular proteome were visualized: different proteins profiles at these two growth rates. The 0.09 h-1 growth rate showed larger number of bands using colloidal Coma ssie Blue staining. Different bands were detected at these two growth rates when the PAS assay for glycoprotein detection in polyacrylamide gel was used. The two-dimensional chromatogram profiles were comparatively distinguished between the 0.03 h -1 and 0.09 h -1 growth rate samples. Protein peaks from the second dimension, were subjected to mass spectrometry. The mass spectrums visualized showed glycosylated proteins with N-acetylglucosamine molecules and 8, 9 or 15 hexoses molecules. Comparisons between the proteins averaged mass values with the deduced proteins masses from K. lactis secreted proteins database indicated possible post-translational modifications, such as post-translational proteolysis, acetylation, deamidation and myristoylation

Glycoprotein biosynthesis by human normal platelets

International Nuclear Information System (INIS)

Rodriguez, P.; Bello, O.; Apitz-Castro, R.

1987-01-01

Incorporation of radioactive Man, Gal, Fuc, Glc-N, and NANA into washed human normal platelets and endogenous glycoproteins has been found. Both parameters were time dependent. Analysis of hydrolyzed labeled glycoproteins by paper chromatography revealed that the radioactive monosaccharide incubated with the platelets had not been converted into other sugars. Acid hydrolysis demonstrates the presence of a glycosidic linkage. All the effort directed to the demonstration of the existence of a lipid-sugar intermediate in intact human platelets yielded negative results for Man and Glc-N used as precursors. The incorporation of these sugars into glycoproteins is insensitive to bacitracin, suggesting no involvement of lipid-linked saccharides in the synthesis of glycoproteins in human blood platelets. The absence of inhibition of the glycosylation process in the presence of cycloheximide suggests that the sugars are added to proteins present in the intact platelets. These results support the contention that glycoprotein biosynthesis in human blood platelets observed under our experimental conditions is effected through direct sugar nucleotide glycosylation

Effect of dietary fat on hepatic liver X receptor expression in P-glycoprotein deficient mice: implications for cholesterol metabolism

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Lee Stephen D

2008-06-01

Full Text Available Abstract Pgp (P-glycoprotein, MDR1, ABCB1 is an energy-dependent drug efflux pump that is a member of the ATP-binding cassette (ABC family of proteins. Preliminary studies have reported that nonspecific inhibitors of Pgp affect synthesis and esterification of cholesterol, putatively by blocking trafficking of cholesterol from the plasma membrane to the endoplasmic reticulum, and that relative increases in Pgp within a given cell type are associated with increased accumulation of cholesterol. Several key efflux proteins involved in the cholesterol metabolic pathway are transcriptionally regulated by the nuclear hormone liver X receptor (LXR. Therefore, to examine the interplay between P-glycoprotein and the cholesterol metabolic pathway, we utilized a high fat, normal cholesterol diet to upregulate LXRα without affecting dietary cholesterol. Our research has demonstrated that mice lacking in P-glycoprotein do not exhibit alterations in hepatic total cholesterol storage, circulating plasma total cholesterol levels, or total cholesterol concentration in the bile when compared to control animals on either a normal (25% calories from dietary fat or high fat (45% calories from dietary fat diet. However, p-glycoprotein deficient mice (Mdr1a-/-/1b-/- exhibit increased hepatic LXRα protein expression and an elevation in fecal cholesterol concentration when compared to controls.

Extracellular clusterin promotes neuronal network complexity in vitro

DEFF Research Database (Denmark)

Wicher, Grzegorz; Velsecchi, Isabel; Charnay, Yves

2008-01-01

Clusterin (apolipoprotein J), a highly conserved amphiphatic glycoprotein and chaperone, has been implicated in a wide range of physiological and pathological processes. As a secreted protein, clusterin has been shown to act extracellularly where it is involved in lipid transportation and clearan...

Melatonin and Angelman Syndrome: Implications and Mathematical Model of Diurnal Secretion

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Justyna Paprocka

2017-01-01

Full Text Available The main aim of the study was to compare the melatonin rhythms in subjects with Angelman syndrome (n=9 and in children with (n=80 and without (n=40 epilepsy (nonepileptic patients diagnosed with peripheral nerve palsies, myopathy, and back pain using our mathematical model of melatonin circadian secretion. The characteristics describing the diurnal hormone secretion such as minimum melatonin concentration, release amplitude, phase shift of melatonin release, and sleep duration as well as the dim light melatonin onset (DLMO of melatonin secretion and the γ shape parameter allow analyzing the fit and deducing about how much the measured melatonin profile differs from a physiological bell-shaped secretion. The estimated sleep duration and phase shift of melatonin release as well as the DMLO offsets at 25% and 50% relative thresholds are the key characteristic of Angelman syndrome children. As revealed from the γ shape parameter, the melatonin secretion profiles are disturbed in majority of the AG subjects revealing rather a triangular course instead of the bell-like one.

Gibberellic Acid-Induced Aleurone Layers Responding to Heat Shock or Tunicamycin Provide Insight into the N-Glycoproteome, Protein Secretion, and Endoplasmic Reticulum Stress

DEFF Research Database (Denmark)

Barba Espin, Gregorio; Dedvisitsakul, Plaipol; Hägglund, Per

2014-01-01

respond to gibberellic acid by secreting an array of proteins and provide a unique system for the analysis of plant protein secretion. Perturbation of protein secretion in gibberellic acid-induced aleurone layers by two independent mechanisms, heat shock and tunicamycin treatment, demonstrated overlapping...... and secretion, such as calreticulin, protein disulfide isomerase, proteasome subunits, and isopentenyl diphosphate isomerase. Sixteen heat shock proteins in 29 spots showed diverse responses to the treatments, with only a minority increasing in response to heat shock. The majority, all of which were small heat...... shock proteins, decreased in heat-shocked aleurone layers. Additionally, glycopeptide enrichment and N-glycosylation analysis identified 73 glycosylation sites in 65 aleurone layer proteins, with 53 of the glycoproteins found in extracellular fractions and 36 found in intracellular fractions...

Shedding of soluble glycoprotein 1 detected during acute Lassa virus infection in human subjects

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Momoh Mambu

2010-11-01

Full Text Available Abstract Background Lassa hemorrhagic fever (LHF is a neglected tropical disease with significant impact on the health care system, society, and economy of Western and Central African nations where it is endemic. With a high rate of infection that may lead to morbidity and mortality, understanding how the virus interacts with the host's immune system is of great importance for generating vaccines and therapeutics. Previous work by our group identified a soluble isoform of the Lassa virus (LASV GP1 (sGP1 in vitro resulting from the expression of the glycoprotein complex (GPC gene 12. Though no work has directly been done to demonstrate the function of this soluble isoform in arenaviral infections, evidence points to immunomodulatory effects against the host's immune system mediated by a secreted glycoprotein component in filoviruses, another class of hemorrhagic fever-causing viruses. A significant fraction of shed glycoprotein isoforms during viral infection and biogenesis may attenuate the host's inflammatory response, thereby enhancing viral replication and tissue damage. Such shed glycoprotein mediated effects were previously reported for Ebola virus (EBOV, a filovirus that also causes hemorrhagic fever with nearly 90% fatality rates 345. The identification of an analogous phenomenon in vivo could establish a new correlate of LHF infection leading to the development of sensitive diagnostics targeting the earliest molecular events of the disease. Additionally, the reversal of potentially untoward immunomodulatory functions mediated by sGP1 could potentiate the development of novel therapeutic intervention. To this end, we investigated the presence of sGP1 in the serum of suspected LASV patients admitted to the Kenema Government Hospital (KGH Lassa Fever Ward (LFW, in Kenema, Sierra Leone that tested positive for viral antigen or displayed classical signs of Lassa fever. Results It is reasonable to expect that a narrow window exists for

Secretome analysis to elucidate metalloprotease-dependent ectodomain shedding of glycoproteins during neuronal differentiation.

Science.gov (United States)

Tsumagari, Kazuya; Shirakabe, Kyoko; Ogura, Mayu; Sato, Fuminori; Ishihama, Yasushi; Sehara-Fujisawa, Atsuko

2017-02-01

Many membrane proteins are subjected to limited proteolyses at their juxtamembrane regions, processes referred to as ectodomain shedding. Shedding ectodomains of membrane-bound ligands results in activation of downstream signaling pathways, whereas shedding those of cell adhesion molecules causes loss of cell-cell contacts. Secreted proteomics (secretomics) using high-resolution mass spectrometry would be strong tools for both comprehensive identification and quantitative measurement of membrane proteins that undergo ectodomain shedding. In this study, to elucidate the ectodomain shedding events that occur during neuronal differentiation, we establish a strategy for quantitative secretomics of glycoproteins released from differentiating neuroblastoma cells into culture medium with or without GM6001, a broad-spectrum metalloprotease inhibitor. Considering that most of transmembrane and secreted proteins are N-glycosylated, we include a process of N-glycosylated peptides enrichment as well as isotope tagging in our secretomics workflow. Our results show that differentiating N1E-115 neurons secrete numerous glycosylated polypeptides in metalloprotease-dependent manners. They are derived from cell adhesion molecules such as NCAM1, CADM1, L1CAM, various transporters and receptor proteins. These results show the landscape of ectodomain shedding and other secretory events in differentiating neurons and/or during axon elongation, which should help elucidate the mechanism of neurogenesis and the pathogenesis of neurological disorders. © 2017 Molecular Biology Society of Japan and John Wiley & Sons Australia, Ltd.

Solubilization of glycoproteins of envelope viruses by detergents

International Nuclear Information System (INIS)

Berezin, V.E.; Zaides, V.M.; Artamsnov, A.F.; Isaeva, E.S.; Zhdanov, V.M.

1986-01-01

The action of a number of known ionic and nonionic detergents, as well as the new nonionic detergent MESK, on envelope viruses was investigated. It was shown that the nonionic detergents MESK, Triton X-100, and octyl-β-D-glucopyranoside selectively solubilize the outer glycoproteins of the virus particles. The nonionic detergent MESK has the mildest action. Using MESK, purified glycoproteins of influenza, parainfluenza, Venezuelan equine encephalomyelitis, vesicular stomatitis, rabies, and herpes viruses were obtained. The procedure for obtaining glycoproteins includes incubation of the virus suspension with the detergent MESK, removal of subvirus structures by centrifuging, and purification of glycoproteins from detergents by dialysis. Isolated glycoproteins retain a native structure and biological activity and possess high immunogenicity. The detergent MESK is promising for laboratory tests and with respect to the production of subunit vaccines

Zinc alpha-2 glycoprotein is overproduced in Cushing's syndrome.

Science.gov (United States)

Escoté, Xavier; Aranda, Gloria B; Mora, Mireia; Casals, Gregori; Enseñat, Joaquim; Vidal, Oscar; Esteban, Yaiza; Halperin, Irene; Hanzu, Felicia A

2017-01-01

Cushing syndrome (CS), an endogenous hypercortisolemic condition with increased cardiometabolic morbidity, leads to development of abdominal obesity, insulin resistance, diabetes and proatherogenic dyslipidemia. Zinc alpha-2 glycoprotein (ZAG) is a recently characterized lipolytic adipokine implicated in regulation of adipose tissue metabolism and fat distribution. In vitro and animal studies suggest that glucocorticoids interact with ZAG secretion and action. To assess the relationship between ZAG and glucocorticoids in a human model of hypercortisolism, circulating ZAG levels were tested in patients with CS and its counterpart controls. An observational, cross-sectional study on 39 women, 13 with active CS and 26 controls matched by age and body mass index. Plasma ZAG levels (μg/ml) were measured by ELISA and correlated with hypercortisolism, metabolic, and phenotypic parameters. Plasma ZAG levels were significantly higher in patients with CS compared to controls (64.3±16.6 vs. 44.0±16.1, p=0.002). In a univariate analysis, ZAG levels positively correlated to 24-h urinary free cortisol (p=0.001), body mass index (p=0.02), non-esterified fatty acids (p=0.05), glucose (p=0.003), LDL-C (p=0.028), and type 2 diabetes mellitus (p=0.016), and were inversely related to total adiponectin levels (p=0.035). In a multivariate analysis, after adjusting for CS, ZAG levels only correlated with body mass index (p=0.012), type 2 diabetes mellitus (p=0.004), and glucose (p<0.001). This study provides initial evidence that plasma ZAG levels are higher in patients with CS as compared to controls. The close relationship of ZAG with metabolic and phenotypic changes in CS suggests that ZAG may play a significant role in adipose tissue changes in hypercortisolism. Copyright © 2017 SEEN. Publicado por Elsevier España, S.L.U. All rights reserved.

Nucleic acid-binding glycoproteins which solubilize nucleic acids in dilute acid: re-examination of the Ustilago maydis glycoproteins

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Unrau, P.; Champ, D.R.; Young, J.L.; Grant, C.E.

1980-01-01

Holloman reported the isolation from Ustilago maydis of a glycoprotein which prevented the precipitation of nucleic acids in cold 5% trichloroacetic acid. Two glycoprotein fractions from U. maydis with this nucleic acid-solubilizing activity were isolated in our laboratory using improved purification procedures. The activity was not due to nuclease contamination. The glycoproteins are distinguished by: their ability to bind to concanavalin A-Sepharose; their differential binding to double- and single-stranded deoxyribonucleic acid, and to ribonucleic acid; their molecular weights (46,000 and 69,000); and the relative amounts present in growing versus nongrowing cells. Both fractions required sulfhydryl-reducing conditions for optimal yields, specific activity, and stability. Nucleic acid binding was cooperative, the minimum number of glycoproteins required to make a native T7 DNA molecule soluble in dilute acid being estimated at 2 and 15, respectively.

Developmental localization and the role of hydroxyproline rich glycoproteins during somatic embryogenesis of banana (Musa spp. AAA

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Menzel Diedrik

2011-02-01

Full Text Available Abstract Background Hydroxyproline rich glycoproteins (HRGPs are implicated to have a role in many aspects of plant growth and development but there is limited knowledge about their localization and function during somatic embryogenesis of higher plants. In this study, the localization and function of hydroxyproline rich glycoproteins in embryogenic cells (ECs and somatic embryos of banana were investigated by using immunobloting and immunocytochemistry with monoclonal JIM11 and JIM20 antibodies as well as by treatment with 3,4-dehydro-L-proline (3,4-DHP, an inhibitor of extensin biosynthesis, and by immunomodulation with the JIM11 antibody. Results Immunofluorescence labelling of JIM11 and JIM20 hydroxyproline rich glycoprotein epitopes was relatively weak in non-embryogenic cells (NECs, mainly on the edge of small cell aggregates. On the other hand, hydroxyproline rich glycoprotein epitopes were found to be enriched in early embryogenic cells as well as in various developmental stages of somatic embryos. Embryogenic cells (ECs, proembryos and globular embryos showed strong labelling of hydroxyproline rich glycoprotein epitopes, especially in their cell walls and outer surface layer, so-called extracellular matrix (ECM. This hydroxyproline rich glycoprotein signal at embryo surfaces decreased and/or fully disappeared during later developmental stages (e.g. pear-shaped and cotyledonary stages of embryos. In these later developmental embryogenic stages, however, new prominent hydroxyproline rich glycoprotein labelling appeared in tri-cellular junctions among parenchymatic cells inside these embryos. Overall immunofluorescence labelling of late stage embryos with JIM20 antibody was weaker than that of JIM11. Western blot analysis supported the above immunolocalization data. The treatment with 3,4-DHP inhibited the development of embryogenic cells and decreased the rate of embryo germination. Embryo-like structures, which developed after 3,4-DHP

The ESX system in Bacillus subtilis mediates protein secretion.

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Laura A Huppert

Full Text Available Esat-6 protein secretion systems (ESX or Ess are required for the virulence of several human pathogens, most notably Mycobacterium tuberculosis and Staphylococcus aureus. These secretion systems are defined by a conserved FtsK/SpoIIIE family ATPase and one or more WXG100 family secreted substrates. Gene clusters coding for ESX systems have been identified amongst many organisms including the highly tractable model system, Bacillus subtilis. In this study, we demonstrate that the B. subtilis yuk/yue locus codes for a nonessential ESX secretion system. We develop a functional secretion assay to demonstrate that each of the locus gene products is specifically required for secretion of the WXG100 virulence factor homolog, YukE. We then employ an unbiased approach to search for additional secreted substrates. By quantitative profiling of culture supernatants, we find that YukE may be the sole substrate that depends on the FtsK/SpoIIIE family ATPase for secretion. We discuss potential functional implications for secretion of a unique substrate.

Characterization of swiftlet edible bird nest, a mucin glycoprotein, and its adulterants by Raman microspectroscopy.

Science.gov (United States)

Shim, Eric K S; Chandra, Gleen F; Pedireddy, S; Lee, Soo-Y

2016-09-01

Edible bird's nest (EBN) is made from the glutinous salivary secretion of highly concentrated mucin glycoprotein by swiftlets (genus Aerodramus or Collocalia ) native to the Indo-Pacific region. The unique Raman spectrum of EBN has vibrational lines that can be assigned to peptides and saccharides in the glycoprotein, and it can be used to screen for adulteration. The common edible adulterants classified into two types. Type I adulterants, such as fish bladder, pork skin, karaya gum, coralline seaweed, agar strips, and tremella fungus, were solids which adhered externally on the surface of the EBN cement. They can usually be detected with a microscope based on differences in the surface structure. Type II adulterants were water soluble substances such as saccharides (e.g., glucose, sucrose), polypeptides (e.g., hydrolyzed collagen) and salts (e.g. monosodium glutamate) which can be readily soaked up by the EBN hydrogel when moist and adsorbed internally in the EBN cement matrix forming a composite upon drying, making them difficult to detect visually. The present study showed that Raman microspectroscopy offers a rapid, non-invasive, and label free technique to detect both Type I and II adulterants in EBN.

N-Glycosylation of Carnosinase Influences Protein Secretion and Enzyme Activity Implications for Hyperglycemia

NARCIS (Netherlands)

Riedl, Eva; Koeppel, Hannes; Pfister, Frederick; Peters, Verena; Sauerhoefer, Sibylle; Sternik, Paula; Brinkkoetter, Paul; Zentgraf, Hanswalter; Navis, Gerjan; Henning, Robert H.; Van Den Born, Jacob; Bakker, Stephan J. L.; Janssen, Bart; van der Woude, Fokko J.; Yard, Benito A.

OBJECTIVE-The (CTG)(n) polymorphism in the serum carnosinase (CN-1) gene affects CN-1 secretion Since CN-1 is heavily glycosylated and glycosylation might influence protein secretion as well, we tested the role of N-glycosylation for CN-1 secretion and enzyme activity. We also tested whether CN-1

P-glycoprotein Inhibition by the Agricultural Pesticide Propiconazole and Its Hydroxylated Metabolites: Implications for Pesticide-Drug Interactions.

Science.gov (United States)

The human efflux transporter P-glycoprotein (P-gp; MDR1) functions an important cellular defense system against a variety of xenobiotics; however, little information exists on whether environmental chemicals interact with P-gp. Conazoles provide a unique challenge to exposure ass...

An improved radioimmunoassay for urinary Tamm-Horsfall glycoprotein

International Nuclear Information System (INIS)

Dawnay, A.B. St. J.; Thornley, C.; Cattell, W.R.

1982-01-01

A rapid specific radioimmunoassay has been used to measure Tamm-Horsfall glycoprotein (TH glycoprotein) in urine, and the method described. The apparent concentration increased with increasing dilution of urine in water, reaching a plateau at 1 in 20. This increase was greater the higher the osmolality and TH glycoprotein concentration and the lower the pH of the original sample. The apparent concentration of TH glycoprotein in neat or diluted urine was not affected by freezing or by storage at 4 0 C or room temperature for at least 2 days. A physiological range for the urinary excretion rate was established as 22-56 mg/24h, (considerably higher than the amount present in serum) based on samples from 29 individuals with normal renal function, as defined by their creatinine clearance. There was no significant correlation between serum concentrations of TH glycoprotein and its urinary excretion rate, nor between urinary excretion rate and creatinine clearance. (author)

Orthobunyavirus ultrastructure and the curious tripodal glycoprotein spike.

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Thomas A Bowden

Full Text Available The genus Orthobunyavirus within the family Bunyaviridae constitutes an expanding group of emerging viruses, which threaten human and animal health. Despite the medical importance, little is known about orthobunyavirus structure, a prerequisite for understanding virus assembly and entry. Here, using electron cryo-tomography, we report the ultrastructure of Bunyamwera virus, the prototypic member of this genus. Whilst Bunyamwera virions are pleomorphic in shape, they display a locally ordered lattice of glycoprotein spikes. Each spike protrudes 18 nm from the viral membrane and becomes disordered upon introduction to an acidic environment. Using sub-tomogram averaging, we derived a three-dimensional model of the trimeric pre-fusion glycoprotein spike to 3-nm resolution. The glycoprotein spike consists mainly of the putative class-II fusion glycoprotein and exhibits a unique tripod-like arrangement. Protein-protein contacts between neighbouring spikes occur at membrane-proximal regions and intra-spike contacts at membrane-distal regions. This trimeric assembly deviates from previously observed fusion glycoprotein arrangements, suggesting a greater than anticipated repertoire of viral fusion glycoprotein oligomerization. Our study provides evidence of a pH-dependent conformational change that occurs during orthobunyaviral entry into host cells and a blueprint for the structure of this group of emerging pathogens.

The glycoprotein of measles virus

International Nuclear Information System (INIS)

Anttonen, O.; Jokinen, M.; Salmi, A.; Vainionpaeae, R.; Gahmberg, C.G.

1980-01-01

Measles virus was propagated in VERO cells and purified from the culture supernatants by two successive tartrate-density-gradient centrifugations. Surface carbohydrates were labelled both in vitro and in vivo with 3 H after treatment with galactose oxidase/NaB 3 H 4 or with [ 3 H]glucosamine. The major labelled glycoprotein in measles virions had a mol.wt. of 79000. After labelling with periodate/NaB 3 H 4 , which would result in specific labelling of sialic acid residues, the 79000-mol.wt. glycoprotein was very weakly labelled. This suggested that there is no or a very low amount of sialic acid in the virions. Further analysis of the glycoprotein showed that galactose is the terminal carbohydrate unit in the oligosaccharide, and the molecular weight of the glycopeptide obtained after Pronase digestion is about 3000. The oligosaccharide is attached to the polypeptide through an alkali-stable bond, indicating a N-glycosidic asparagine linkage. (author)

Immunization with a dicistronic plasmid expressing a truncated form of bovine herpesvirus-1 glycoprotein D and the amino-terminal subunit of glycoprotein B results in reduced gB-specific immune responses

International Nuclear Information System (INIS)

Manoj, Sharmila; Babiuk, Lorne A.; Drunen Littel van-Hurk, Sylvia van den

2003-01-01

As an approach to create a divalent DNA vaccine, a truncated secreted version of bovine herpesvirus-1 (BHV-1) glycoprotein D (tgD) and the amino-terminal subunit of glycoprotein B (gBb) were expressed from a dicistronic plasmid, designated pSLIAtgD-IRES-gBb. Intradermal immunization of mice with pSLIAtgD-IRES-gBb or a mixture of plasmids encoding tgD (pSLIAtgD) and gBb (pSLIAgBb) by needle injection or gene gun elicited strong tgD-specific immune responses. However, a significant reduction in gBb-specific immune responses was observed upon immunization of mice with pSLIAtgD-IRES-gBb or a mixture of pSLIAtgD and pSLIAgBb in comparison to immunization with pSLIAgBb alone. This reduction in gBb-specific immune responses induced by pSLIAtgD-IRES-gBb was due to production of low amounts of gBb from pSLIAtgD-IRES-gBb, inefficient processing and transport of gBb, and possibly competition for antigen-presenting cells by tgD and gBb. These results indicate that, although divalent plasmids may be used to express different antigens, the efficacy of vaccination with such plasmids may be influenced by the plasmid design and the characteristics of the expressed antigens

Effects of preventing O-glycosylation on the secretion of human chorionic gonadotropin in Chinese hamster ovary cells

International Nuclear Information System (INIS)

Matzuk, M.M.; Krieger, M.; Corless, C.L.; Boime, I.

1987-01-01

Human chorionic gonadotropin (hCG) is a member of a family of heterodimeric glycoprotein hormones that have a common α subunit but differ in their hormone-specific β-subunits. The β subunit of hCG (hCGβ) is unique among the β subunits in that it contains four mucin-like O-linked oligosaccharides attached to a carboxyl-terminal extension. To study the effects of O-glycosylation on the secretion and assembly of hCG, expression vectors containing either hCGβ gene alone or together with the hCGα gene were transfected into a mutant Chinese hamster ovary cell line, 1d1D, which exhibits a reversible defect in O-glycosylation. The results reveal that hCGβ can be secreted normally in the absence of its O-linked oligosaccharides. hCGβ devoid of O-linked carbohydrate can also combine efficiently with hCGα and be secreted as an intact dimer. The authors conclude that in Chinese hamster ovary cells, the hCGβ O-linked chains play no role in the assembly and secretion of hCG. The normal and O-linked oligosaccharide-deficient forms of hCG secreted by these cells should prove useful in examining the role of O-linked chains on the biological function of hCG

Isolation of allergenically active glycoprotein from Prosopis juliflora pollen.

Science.gov (United States)

Thakur, I S

1989-03-01

An allergenically active glycoprotein was homogeneously isolated from the aqueous extract of Prosopis juliflora pollen by ConA-Sepharose affinity chromatography. The molecular weight of this glycoprotein was 20,000 dalton, determined by gel filtration and SDS-PAGE. This fraction showed a total carbohydrate concentration of 25%. The purified glycoprotein revealed immunochemically most antigenic or allergenic and demonstrated homogeneous after reaction with P. juliflora pollen antiserum, characterized by gel diffusion, Immunoelectrophoresis and Radioallergosorbent test.

Bile salts stimulate mucin secretion by cultured dog gallbladder epithelial cells independent of their detergent effect.

Science.gov (United States)

Klinkspoor, J H; Yoshida, T; Lee, S P

1998-05-15

1. Bile salts stimulate mucin secretion by the gallbladder epithelium. We have investigated whether this stimulatory effect is due to a detergent effect of bile salts. 2. The bile salts taurocholic acid (TC) and tauroursodeoxycholic acid (TUDC) and the detergents Triton X-100 (12.5-400 microM) and Tween-20 (0.1-3.2 mM) were applied to monolayers of cultured dog gallbladder epithelial cells. Mucin secretion was studied by measuring the secretion of [3H]N-acetyl-d-glucosamine-labelled glycoproteins. We also attempted to alter the fluidity of the apical membrane of the cells through extraction of cholesterol with beta-cyclodextrin (2.5-15 mM). The effect on TUDC-induced mucin secretion was studied. Cell viability was assessed by measuring lactate dehydrogenase (LDH) leakage or 51Cr release. 3. In contrast with the bile salts, the detergents were not able to cause an increase in mucin secretion without causing concomitant cell lysis. Concentrations of detergent that increased mucin release (>100 microM Triton X-100, >0.8 mM Tween-20), caused increased LDH release. Incubation with beta-cyclodextrin resulted in effective extraction of cholesterol without causing an increase in 51Cr release. However, no effect of the presumed altered membrane fluidity on TUDC (10 mM)-induced mucin secretion was observed. 4. The stimulatory effect of bile salts on mucin secretion by gallbladder epithelial cells is not affected by the fluidity of the apical membrane of the cells and also cannot be mimicked by other detergents. We conclude that the ability of bile salts to cause mucin secretion by the gallbladder epithelium is not determined by their detergent properties.

Macrophage Migration Inhibitory Factor Secretion Is Induced by Ionizing Radiation and Oxidative Stress in Cancer Cells.

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Yashi Gupta

Full Text Available The macrophage migration inhibitory factor (MIF has been increasingly implicated in cancer development and progression by promoting inflammation, angiogenesis, tumor cell survival and immune suppression. MIF is overexpressed in a variety of solid tumor types in part due to its responsiveness to hypoxia inducible factor (HIF driven transcriptional activation. MIF secretion, however, is a poorly understood process owing to the fact that MIF is a leaderless polypeptide that follows a non-classical secretory pathway. Better understanding of MIF processing and release could have therapeutic implications. Here, we have discovered that ionizing radiation (IR and other DNA damaging stresses can induce robust MIF secretion in several cancer cell lines. MIF secretion by IR appears independent of ABCA1, a cholesterol efflux pump that has been implicated previously in MIF secretion. However, MIF secretion is robustly induced by oxidative stress. Importantly, MIF secretion can be observed both in cell culture models as well as in tumors in mice in vivo. Rapid depletion of MIF from tumor cells observed immunohistochemically is coincident with elevated circulating MIF detected in the blood sera of irradiated mice. Given the robust tumor promoting activities of MIF, our results suggest that an innate host response to genotoxic stress may mitigate the beneficial effects of cancer therapy, and that MIF inhibition may improve therapeutic responses.

Analysis of glycoprotein-derived oligosaccharides in glycoproteins detected on two-dimensional gel by capillary electrophoresis using on-line concentration method.

Science.gov (United States)

Kamoda, Satoru; Nakanishi, Yasuharu; Kinoshita, Mitsuhiro; Ishikawa, Rika; Kakehi, Kazuaki

2006-02-17

Capillary electrophoresis (CE) is an effective tool to analyze carbohydrate mixture derived from glycoproteins with high resolution. However, CE has a disadvantage that a few nanoliters of a sample solution are injected to a narrow capillary. Therefore, we have to prepare a sample solution of high concentration for CE analysis. In the present study, we applied head column field-amplified sample stacking method to the analysis of N-linked oligosaccharides derived from glycoprotein separated by two-dimensional gel electrophoresis. Model studies demonstrated that we achieved 60-360 times concentration effect on the analysis of carbohydrate chains labeled with 3-aminobenzoic acid (3-AA). The method was applied to the analysis of N-linked oligosaccharides from glycoproteins separated and detected on PAGE gel. Heterogeneity of alpha1-acid glycoprotein (AGP), i.e. glycoforms, was examined by 2D-PAGE and N-linked oligosaccharides were released by in-gel digestion with PNGase F. The released oligosaccharides were derivatized with 3-AA and analyzed by CE. The results showed that glycoforms having lower pI values contained a larger amount of tetra- and tri-antennary oligosaccharides. In contrast, glycoforms having higher pI values contained bi-antennary oligosaccharides abundantly. The result clearly indicated that the spot of a glycoprotein glycoform detected by Coomassie brilliant blue staining on 2D-PAGE gel is sufficient for quantitative profiling of oligosaccharides.

Humanizing recombinant glycoproteins from Chinese hamster ovary cells

DEFF Research Database (Denmark)

Hansen, Anders Holmgaard; Amann, Thomas; Kol, Stefan

With new tools for gene-editing like zinc-fingers, TALENS and CRISPR, it is now feasible totailor-make the N-Glycoforms for therapeutic glycoproteins that have previously been almost impossible. We here demonstrate a case of humanizing a recombinant human glycoprotein that in Wild type (WT) Chinese...

Determination of P-Glycoprotein Expression by Flow Cytometry in Hematological Malignancies

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Berkay Saraymen

2016-03-01

Full Text Available Objective: Determination the expression of P-glycoprotein is especially problematic for normal tissues because immuno­logical methods are limited in terms of sensitivity. We aimed to determine the expression of P-glycoprotein and CD34 by flow cytometry, and to evaluate the level of expression of P-glycoprotein and CD34 with unresponsive to treatment in pa­tients diagnosed with hematologic malignancy. Methods: Our study included fifty patients diagnosed with acute myeloblastic leukemia and acute lymphoblastic leuke­mia, and twenty healthy controls who were admitted to Erci­yes University Hematology-Oncology Hospital. The suspend­ed cells from bone marrow samples of patients and the pe­ripheral blood samples of healthy people were marked with P-glycoprotein phycoerythrin and CD34 FITC or PerCP Cy 5.5; and then surface expression was measured by means of flow cytometry. Results: In 6 of 30 acute myeloblastic leukemia patients P-glycoprotein and CD34 expression, in 6 of 20 acute lympho­blastic leukemia patients P-glycoprotein, in 5 of them CD34 expression were determined. A significant relation between P-glycoprotein and CD34 expressions in acute myeloblas­tic leukemia and acute lymphoblastic leukemia bone marrow samples was reported. Conclusion: Our data indicate that flow cytometry is more reliable, precise and faster than molecular methods for mea­suring P-glycoprotein expression and suggests the pos­sibility of a significant relationship between P-glycoprotein and CD34 expressions in acute myeloblastic leukemia and acute lymphoblastic leukemia bone marrow samples. The blast cells expressing CD34 on their surface along with P-glycoprotein simultaneously show that multi drug resistance 1 gene is mostly active in immature cells.

Excreted/Secreted Proteins from Trypanosome Procyclic Strains

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Celestine Michelle Atyame Nten

2010-01-01

Full Text Available Trypanosoma secretome was shown to be involved in parasite virulence and is suspected of interfering in parasite life-cycle steps such as establishment in the Glossina midgut, metacyclogenesis. Therefore, we attempted to identify the proteins secreted by procyclic strains of T. brucei gambiense and T. brucei brucei, responsible for human and animal trypanosomiasis, respectively. Using mass spectrometry, 427 and 483 nonredundant proteins were characterized in T. brucei brucei and T. brucei gambiense secretomes, respectively; 35% and 42% of the corresponding secretome proteins were specifically secreted by T. brucei brucei and T. brucei gambiense, respectively, while 279 proteins were common to both subspecies. The proteins were assigned to 12 functional classes. Special attention was paid to the most abundant proteases (14 families because of their potential implication in the infection process and nutrient supply. The presence of proteins usually secreted via an exosome pathway suggests that this type of process is involved in trypanosome ESP secretion. The overall results provide leads for further research to develop novel tools for blocking trypanosome transmission.

Glycoproteins of mouse vaginal epithelium: differential expression related to estrous cyclicity

DEFF Research Database (Denmark)

Horvat, B; Multhaupt, H A; Damjanov, I

1993-01-01

We used lectin overlay blotting and SDS-PAGE to analyze the estrous cycle-specific expression of mouse vaginal epithelial glycoproteins. Seven lectins chosen for their differential carbohydrate-binding specificity revealed 15 glycoproteins that showed cycle-related expression. Each lectin had...... in proestrus, coincident with the transformation of two superficial layers of vaginal squamous epithelium into mucinous cuboidal cells. Electron microscopic lectin histochemistry revealed the glycoproteins in the mucinous granules of surface cuboidal cells and in the lumen of the vagina. Our results illustrate...... the complexity of glycoconjugate synthesis in mouse vagina and reveal the distinct cycle-specific patterns of individual glycoprotein expression. These cyclic glycoproteins could serve as vaginal biochemical markers for the specific phases of the estrous cycle....

Herpesvirus glycoproteins undergo multiple antigenic changes before membrane fusion.

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Daniel L Glauser

Full Text Available Herpesvirus entry is a complicated process involving multiple virion glycoproteins and culminating in membrane fusion. Glycoprotein conformation changes are likely to play key roles. Studies of recombinant glycoproteins have revealed some structural features of the virion fusion machinery. However, how the virion glycoproteins change during infection remains unclear. Here using conformation-specific monoclonal antibodies we show in situ that each component of the Murid Herpesvirus-4 (MuHV-4 entry machinery--gB, gH/gL and gp150--changes in antigenicity before tegument protein release begins. Further changes then occurred upon actual membrane fusion. Thus virions revealed their final fusogenic form only in late endosomes. The substantial antigenic differences between this form and that of extracellular virions suggested that antibodies have only a limited opportunity to block virion membrane fusion.

Three-Dimensionally Functionalized Reverse Phase Glycoprotein Array for Cancer Biomarker Discovery and Validation.

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Pan, Li; Aguilar, Hillary Andaluz; Wang, Linna; Iliuk, Anton; Tao, W Andy

2016-11-30

Glycoproteins have vast structural diversity that plays an important role in many biological processes and have great potential as disease biomarkers. Here, we report a novel functionalized reverse phase protein array (RPPA), termed polymer-based reverse phase glycoprotein array (polyGPA), to capture and profile glycoproteomes specifically, and validate glycoproteins. Nitrocellulose membrane functionalized with globular hydroxyaminodendrimers was used to covalently capture preoxidized glycans on glycoproteins from complex protein samples such as biofluids. The captured glycoproteins were subsequently detected using the same validated antibodies as in RPPA. We demonstrated the outstanding specificity, sensitivity, and quantitative capabilities of polyGPA by capturing and detecting purified as well as endogenous α-1-acid glycoprotein (AGP) in human plasma. We further applied quantitative N-glycoproteomics and the strategy to validate a panel of glycoproteins identified as potential biomarkers for bladder cancer by analyzing urine glycoproteins from bladder cancer patients or matched healthy individuals.

Glycoprotein Enrichment Analytical Techniques: Advantages and Disadvantages.

Science.gov (United States)

Zhu, R; Zacharias, L; Wooding, K M; Peng, W; Mechref, Y

2017-01-01

Protein glycosylation is one of the most important posttranslational modifications. Numerous biological functions are related to protein glycosylation. However, analytical challenges remain in the glycoprotein analysis. To overcome the challenges associated with glycoprotein analysis, many analytical techniques were developed in recent years. Enrichment methods were used to improve the sensitivity of detection, while HPLC and mass spectrometry methods were developed to facilitate the separation of glycopeptides/proteins and enhance detection, respectively. Fragmentation techniques applied in modern mass spectrometers allow the structural interpretation of glycopeptides/proteins, while automated software tools started replacing manual processing to improve the reliability and throughput of the analysis. In this chapter, the current methodologies of glycoprotein analysis were discussed. Multiple analytical techniques are compared, and advantages and disadvantages of each technique are highlighted. © 2017 Elsevier Inc. All rights reserved.

Developing baculovirus-insect cell expression systems for humanized recombinant glycoprotein production

International Nuclear Information System (INIS)

Jarvis, Donald L.

2003-01-01

The baculovirus-insect cell expression system is widely used to produce recombinant glycoproteins for many different biomedical applications. However, due to the fundamental nature of insect glycoprotein processing pathways, this system is typically unable to produce recombinant mammalian glycoproteins with authentic oligosaccharide side chains. This minireview summarizes our current understanding of insect protein glycosylation pathways and our recent efforts to address this problem. These efforts have yielded new insect cell lines and baculoviral vectors that can produce recombinant glycoproteins with humanized oligosaccharide side chains

Regulation of glycoprotein synthesis in yeast by mating pheromones

International Nuclear Information System (INIS)

Tanner, W.

1984-01-01

In Saccharomyces cerevisiae, glycosylated proteins amount to less than 2% of the cell protein. Two intensively studied examples of yeast glycoproteins are the external cell wall - associated invertase and the vacuolar carboxypeptidase Y. Recently, it was shown that the mating pheromone, alpha factor, specifically and strongly inhibits the synthesis of N-glycosylated proteins in haploid a cells, whereas O-glycosylated proteins are not affected. In this paper, the pathways of glycoprotein biosynthesis are summarized briefly, and evidence is presented that mating pheomones have a regulatory function in glycoprotein synthesis

Engineered CHO cells for production of diverse, homogeneous glycoproteins

DEFF Research Database (Denmark)

Yang, Zhang; Wang, Shengjun; Halim, Adnan

2015-01-01

Production of glycoprotein therapeutics in Chinese hamster ovary (CHO) cells is limited by the cells' generic capacity for N-glycosylation, and production of glycoproteins with desirable homogeneous glycoforms remains a challenge. We conducted a comprehensive knockout screen of glycosyltransferas...

Bioinformatics Analysis of Envelope Glycoprotein E epitopes of ...

African Journals Online (AJOL)

The E glycoprotein of dengue virus is responsible for the viral binding to the receptor. The crystal structure of envelope glycoprotein has already been determined. However, where the well-defined Bcell and T-cell epitopes are located is still a question. Because of the large variations among the four dengue genotypes, it is ...

The Purification of a Blood Group A Glycoprotein: An Affinity Chromatography Experiment.

Science.gov (United States)

Estelrich, J.; Pouplana, R.

1988-01-01

Describes a purification process through affinity chromatography necessary to obtain specific blood group glycoproteins from erythrocytic membranes. Discusses the preparation of erythrocytic membranes, extraction of glycoprotein from membranes, affinity chromatography purification, determination of glycoproteins, and results. (CW)

Pheochromocytoma with Negative Metanephrines: A Rarity and the Significance of Dopamine Secreting Tumors

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Michael Bozin

2017-05-01

Full Text Available We describe a case of a 25-year-old female with a dopamine secreting PPGL diagnosed retrospectively with biochemical analysis. This finding resulted in change in approach to investigation and management, given their important clinical implications. There are important differences in management of dopamine secreting PPGL compared to classical noradrenaline and adrenaline-secreting PPGL. This includes the risk of peri-operative cardiovascular collapse peri-operatively with alpha/beta blockade, risk of malignancy/recurrence, and associated genetic abnormalities.

Role of Nitric Oxide in the Regulation of Renin and Vasopressin Secretion

Science.gov (United States)

Reid, Ian A.

1994-01-01

Research during recent years has established nitric oxide as a unique signaling molecule that plays important roles in the regulation of the cardiovascular, nervous, immune, and other systems. Nitric oxide has also been implicated in the control of the secretion of hormones by the pancreas, hypothalamus, and anterior pituitary gland, and evidence is accumulating that it contributes to the regulation of the secretion of renin and vasopressin, hormones that play key roles in the control of sodium and water balance. Several lines of evidence have implicated nitric oxide in the control of renin secretion. The enzyme nitric oxide synthase is present in vascular and tubular elements of the kidney, particularly in cells of the macula densa, a structure that plays an important role in the control of renin secretion. Guanylyl cyclase, a major target for nitric oxide, is also present in the kidney. Drugs that inhibit nitric oxide synthesis generally suppress renin release in vivo and in vitro, suggesting a stimulatory role for the L-arginine/nitric oxide pathway in the control of renin secretion. Under some conditions, however, blockade of nitric oxide synthesis increases renin secretion. Recent studies indicate that nitric oxide not only contributes to the regulation of basal renin secretion, but also participates in the renin secretory responses to activation of the renal baroreceptor, macula densa, and beta adrenoceptor mechanisms that regulate renin secretion. Histochemical and immunocytochemical studies have revealed the presence of nitric oxide synthase in the supraoptic and paraventricular nuclei of the hypothalamus and in the posterior pituitary gland. Colocalization of nitric oxide synthase and vasopressin has been demonstrated in some hypothalamic neurons. Nitric oxide synthase activity in the hypothalamus and pituitary is increased by maneuvers known to stimulate vasopressin secretion, including salt loading and dehydration, Administration of L-arginine and nitric

Direct analysis of the secretions of the potato cyst nematode Globodera rostochiensis.

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Robertson, L; Robertson, W M; Jones, J T

1999-08-01

Secretions were induced from second (invasive) stage juveniles (J2s) of the potato cyst nematode Globodera rostochiensis by exposing them to 5-methoxy-N,N-dimethyl tryptamine oxalate (DMT). Secretions were collected from J2s in sufficient quantity to allow direct analysis. Gel electrophoresis followed by monochromatic silver staining demonstrated the presence of at least 10 proteins. The presence of several enzymes, including superoxide dismutase and proteases, was demonstrated using Western blots and activity assays. Antisera raised against the secretions recognized bands on Western blots consistent in molecular mass with those identified on silver stained gels. The antisera recognized structures implicated in the production of secretions including the subventral gland cells and surface of J2s.

Isolation and characterization of two antigenic glycoproteins from the pollen of Prosopis juliflora.

Science.gov (United States)

Thakur, I S

1991-03-01

Two antigenically active glycoprotein fractions were isolated from crude extract of the pollen of Prosopis juliflora using DEAE-cellulose ion exchange chromatography. The glycoproteins gave single band on polyacrylamide gel electrophoresis. The molecular weight of these two glycoprotein was 20,000 and 10,000 as determined by gel filtration on Sephadex G-75. With the help of crossed immunoelectrophoresis and gel diffusion crude extract exhibited twelve and three precipitating antigens suggesting its heterogeneous nature; and the purified glycoprotein fractions however formed single precipitin band on gel diffusion test and immunoelectrophoresis. As tested by ELISA the polyclonal antisera raised in rabbit showed strong binding affinity with glycoprotein of MW 20,000. These result indicates that the two glycoprotein fractions are not antigenically identical.

Mechanisms for lymphocytic choriomeningitis virus glycoprotein cleavage, transport, and incorporation into virions

International Nuclear Information System (INIS)

Kunz, Stefan; Edelmann, Kurt H.; Torre, Juan-Carlos de la; Gorney, Robert; Oldstone, Michael B.A.

2003-01-01

The glycoprotein (GP) of lymphocytic choriomeningitis virus (LCMV) serves as virus attachment protein to its receptor on host cells and is a key determinant for cell tropism, pathogenesis, and epidemiology of the virus. The GP of LCMV is posttranslationally cleaved by the subtilase SKI-1/S1P into two subunits, the peripheral GP1, which is implicated in receptor binding, and the transmembrane GP2 that is structurally similar to the fusion active membrane proximal portions of the glycoproteins of other enveloped viruses. The present study shows that cleavage by SKI-1/S1P is not required for cell surface expression of LCMVGP on infected cells but is essential for its incorporation into virions and for the production of infectious virus particles. In absence of SKI-1/S1P cleavage, cell-to-cell propagation of the virus was markedly reduced. Further, proteolytic processing of LCMVGP depends on the presence of a cluster of basic amino acids at the C-terminus of the cytoplasmic domain of GP2, a structural motif that is conserved in Old World arenaviruses. The effect of the truncation of the cytoplasmic tail on cleavage suggests a structural interdependence between the cytoplasmic domain and the ectodomains of LCMVGP

Evaluation of electrical aggregometry: comparison with optical aggregometry, secretion of ATP, and accumulation of radiolabeled platelets

International Nuclear Information System (INIS)

Ingerman-Wojenski, C.; Smith, J.B.; Silver, M.J.

1983-01-01

Platelet aggregation has been most commonly studied in vitro by measuring increases in light transmission as platelets aggregate in PRP (platelet-rich plasma). Recently, an electrical impedance method for measuring platelet aggregation has been introduced. This method can be used with either PRP or whole blood and measures an increase in impedance across electrodes placed in the blood samples as platelets accumulate on them. Results obtained by the two methods were compared using ADP and collagen as aggregating agents, and also have measured the secretion of platelet ATP simultaneously. Although the aggregometry results were similar, recordings obtained by the electrical method did not distinguish two waves of platelet aggregation or correlate with secretion as well as recordings obtained by the optical method. When PGI 2 (prostacyclin) or PGE 1 (prostaglandin E 1 ) was added to the PRP, both the rate and extent of the increase in light transmittance were inhibited, but the main effect on the increase in impedance was a decrease in its rate and not in its extent. Increases in impedance and secretion of ATP were also measured in whole blood after the platelets had been labeled with a 125 I-containing antibody specific for platelet surface glycoproteins. It appeared that the increases in impedance lagged several minutes behind the formation of platelet aggregates and the secretion of platelet ATP

Purification and characterization of the glycoprotein allergen from Prosopis juliflora pollen.

Science.gov (United States)

Thakur, I S

1991-02-01

Highly active glycoprotein allergens have been isolated from pollen of Prosopis juliflora by a combination of Sephadex G-100 gel filtration and Sodium dodecyl sulphate-Poly-acrylamide gel electrophoresis. The glycoprotein fraction was homogeneous, and had molecular weight 20,000. The purified glycoprotein allergen contained 20% carbohydrate, mainly arabinose and galactose. Enzymatic digestion of glycoprotein with protease released glycopeptides of molecular weight ranging from less than 1,000 to more than 5,000 on Sephadex G-25 gel filtration. Antigenicity or allergenicity testing of these glycopeptides by immunodiffusion, immunoelectrophoresis, and radioallergosorbent test indicated complete loss of allergenic activity after digestion with protease whereas incubation with beta-D-galactosidase and periodate oxidation had little affect on the allergenic activity of the glycoprotein fraction. But incubation with alpha-D-glucosidase did not affect the allergenic activity significantly. All these tests indicated that protein played significant role in allergenicity of P. juliflora pollen.

Strategies to overcome or circumvent P-glycoprotein mediated multidrug resistance.

Science.gov (United States)

Yuan, Hongyu; Li, Xun; Wu, Jifeng; Li, Jinpei; Qu, Xianjun; Xu, Wenfang; Tang, Wei

2008-01-01

Cancer patients who receive chemotherapy often experience intrinsic or acquired resistance to a broad spectrum of chemotherapeutic agents. The phenomenon, termed multidrug resistance (MDR), is often associated with the over-expression of P-glycoprotein, a transmembrane protein pump, which can enhance efflux of a various chemicals structurally unrelated at the expense of ATP depletion, resulting in decrease of the intracellular cytotoxic drug accumulation. The MDR has been a big threaten to the human health and the war fight for it continues. Although several other mechanisms for MDR are elucidated in recent years, considerable efforts attempting to inverse MDR are involved in exploring P-glycoprotein modulators and suppressing P-glycoprotein expression. In this review, we will report on the recent advances in various strategies for overcoming or circumventing MDR mediated by P-glycoprotein.

Inhibition of collagen production in scleroderma fibroblast cultures by a connective tissue glycoprotein extracted from normal dermis

International Nuclear Information System (INIS)

Maquart, F.X.; Bellon, G.; Cornillet-Stoupy, J.; Randoux, A.; Triller, R.; Kalis, B.; Borel, J.P.

1985-01-01

It was shown in a previous paper that a connective tissue glycoprotein (CTGP) extracted from normal rabbit dermis was able to inhibit total protein and collagen syntheses by normal dermis fibroblast cultures. In the present study, the effects of CTGP on scleroderma fibroblasts were investigated. [ 14 C]Proline incorporation into total proteins of the supernatant was not significantly different from that found in controls. By contrast, the amount of collagen, expressed as percentage of total secreted protein, was far higher in scleroderma cultures than in normal ones (14.4% +/- 6.0% vs 4.6% +/- 0.9%). Addition of CTGP to the medium induced a concentration-dependent inhibition of [ 14 C]proline incorporation into proteins from both control and scleroderma cells. In control cultures, no significant decrease of the percentage of collagen was observed, but over 60 micrograms/ml, both cytotoxic effects and inhibition of protein synthesis occurred. In scleroderma cultures, the inhibition was twice as effective on collagen as on noncollagen protein synthesis. The inhibition of collagen secretion was not related either to changes in collagen hydroxylation or to the intracellular catabolism of newly synthesized procollagen

A Functional Henipavirus Envelope Glycoprotein Pseudotyped Lentivirus Assay System

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Broder Christopher C

2010-11-01

Full Text Available Abstract Background Hendra virus (HeV and Nipah virus (NiV are newly emerged zoonotic paramyxoviruses discovered during outbreaks in Queensland, Australia in 1994 and peninsular Malaysia in 1998/9 respectively and classified within the new Henipavirus genus. Both viruses can infect a broad range of mammalian species causing severe and often-lethal disease in humans and animals, and repeated outbreaks continue to occur. Extensive laboratory studies on the host cell infection stage of HeV and NiV and the roles of their envelope glycoproteins have been hampered by their highly pathogenic nature and restriction to biosafety level-4 (BSL-4 containment. To circumvent this problem, we have developed a henipavirus envelope glycoprotein pseudotyped lentivirus assay system using either a luciferase gene or green fluorescent protein (GFP gene encoding human immunodeficiency virus type-1 (HIV-1 genome in conjunction with the HeV and NiV fusion (F and attachment (G glycoproteins. Results Functional retrovirus particles pseudotyped with henipavirus F and G glycoproteins displayed proper target cell tropism and entry and infection was dependent on the presence of the HeV and NiV receptors ephrinB2 or B3 on target cells. The functional specificity of the assay was confirmed by the lack of reporter-gene signals when particles bearing either only the F or only G glycoprotein were prepared and assayed. Virus entry could be specifically blocked when infection was carried out in the presence of a fusion inhibiting C-terminal heptad (HR-2 peptide, a well-characterized, cross-reactive, neutralizing human mAb specific for the henipavirus G glycoprotein, and soluble ephrinB2 and B3 receptors. In addition, the utility of the assay was also demonstrated by an examination of the influence of the cytoplasmic tail of F in its fusion activity and incorporation into pseudotyped virus particles by generating and testing a panel of truncation mutants of NiV and HeV F

Identification of oligo-N-glycolylneuraminic acid residues in mammal-derived glycoproteins by a newly developed immunochemical reagent and biochemical methods.

Science.gov (United States)

Sato, C; Kitajima, K; Inoue, S; Inoue, Y

1998-01-30

The occurrence of the alpha2-->8-linked oligomeric form of N-glycolylneuraminic acid (oligo-Neu5Gc) residues in mammalian glycoproteins was unequivocally demonstrated using a newly developed anti-oligo/poly-Neu5Gc monoclonal antibody as well as by chemical and biochemical methods. First, the antibody, designated mAb.2-4B, which specifically recognized oligo/poly-Neu5Gc with a degree of polymerization of >2, was developed by establishing a hybridoma cell line from P3U1 myeloma cells fused with splenocytes from an MRL autoimmune mouse immunized with dipalmitoylphosphatidylethanolamine-conjugated oligo/poly-Neu5Gc. Second, oligo-Neu5Gc was shown to occur in glycoproteins derived from pig spleen by Western blot analysis using mAb.2-4B, which was also confirmed by fluorometric high performance liquid chromatographic analysis of the product of periodate oxidation/reduction/acid hydrolysis of the purified glycopeptide fractions and by TLC and 600-MHz 1H NMR spectroscopic analysis of their mild acid hydrolysates. Finally, the ubiquitous occurrence of oligo-Neu5Gc chains as glycoproteinaceous components in Wistar rat tissue was immunochemically indicated. This is the first example demonstrating the diversity in oligo/poly-Sia structure in mammalian glycoproteins, where only poly-N-acetylneuraminic acid is known to occur. Such diversity in oligo/poly-Sia structure also implicates a diverged array of biological functions of this glycan unit in glycoproteins.

Labelled antibody techniques in glycoprotein estimation

International Nuclear Information System (INIS)

Hazra, D.K.; Ekins, R.P.; Edwards, R.; Williams, E.S.

1977-01-01

The problems in the radioimmunoassay of the glycoprotein hormones (pituitary LH, FSH and TSH and human chlorionic gonadotrophin HGG) are reviewed viz: limited specificity and sensitivity in the clinical context, interpretation of disparity between bioassay and radioimmunoassay, and interlaboratory variability. The advantages and limitations of the labelled antibody techniques - classical immonoradiometric methods and 2-site or 125 I-anti-IgG indirect labelling modifications are reviewed in general, and their theoretical potential in glycoprotein assays examined in the light of previous work. Preliminary experiments in the development of coated tube 2-site assay for glycoproteins using 125 I anti-IgG labelling are described, including conditions for maximizing solid phase extraction of the antigen, iodination of anti-IgG, and assay conditions such as effects of temperature of incubation with antigen 'hormonefree serum', heterologous serum and detergent washing. Experiments with extraction and antigen-specific antisera raised in the same or different species are described as exemplified by LH and TSH assay systems, the latter apparently promising greater sensitivity than radioimmunoassay. Proposed experimental and mathematical optimisation and validation of the method as an assay system is outlined, and the areas for further work delineated. (orig.) [de

Structures and Functions of Pestivirus Glycoproteins: Not Simply Surface Matters.

Science.gov (United States)

Wang, Fun-In; Deng, Ming-Chung; Huang, Yu-Liang; Chang, Chia-Yi

2015-06-29

Pestiviruses, which include economically important animal pathogens such as bovine viral diarrhea virus and classical swine fever virus, possess three envelope glycoproteins, namely Erns, E1, and E2. This article discusses the structures and functions of these glycoproteins and their effects on viral pathogenicity in cells in culture and in animal hosts. E2 is the most important structural protein as it interacts with cell surface receptors that determine cell tropism and induces neutralizing antibody and cytotoxic T-lymphocyte responses. All three glycoproteins are involved in virus attachment and entry into target cells. E1-E2 heterodimers are essential for viral entry and infectivity. Erns is unique because it possesses intrinsic ribonuclease (RNase) activity that can inhibit the production of type I interferons and assist in the development of persistent infections. These glycoproteins are localized to the virion surface; however, variations in amino acids and antigenic structures, disulfide bond formation, glycosylation, and RNase activity can ultimately affect the virulence of pestiviruses in animals. Along with mutations that are driven by selection pressure, antigenic differences in glycoproteins influence the efficacy of vaccines and determine the appropriateness of the vaccines that are currently being used in the field.

Small proteins of plant-pathogenic fungi secreted during host colonization.

NARCIS (Netherlands)

Rep, M.

2005-01-01

Small proteins secreted by plant pathogenic fungi in their hosts have been implicated in disease symptom development as well as in R-gene mediated disease resistance. Characteristically, this class of proteins shows very limited phylogenetic distribution, possibly due to accelerated evolution

Adipokine zinc-α2-glycoprotein regulated by growth hormone and linked to insulin sensitivity.

Science.gov (United States)

Balaz, Miroslav; Ukropcova, Barbara; Kurdiova, Timea; Gajdosechova, Lucia; Vlcek, Miroslav; Janakova, Zuzana; Fedeles, Jozef; Pura, Mikulas; Gasperikova, Daniela; Smith, Steven R; Tkacova, Ruzena; Klimes, Iwar; Payer, Juraj; Wolfrum, Christian; Ukropec, Jozef

2015-02-01

Hypertrophic obesity is associated with impaired insulin sensitivity and lipid-mobilizing activity of zinc-α2-glycoprotein. Adipose tissue (AT) of growth hormone (GH) -deficient patients is characterized by extreme adipocyte hypertrophy due to defects in AT lipid metabolism. It was hypothesized that zinc-α2-glycoprotein is regulated by GH and mediates some of its beneficial effects in AT. AT from patients with GH deficiency and individuals with obesity-related GH deficit was obtained before and after 5-year and 24-month GH supplementation therapy. GH action was tested in primary human adipocytes. Relationships of GH and zinc-α2-glycoprotein with adipocyte size and insulin sensitivity were evaluated in nondiabetic patients with noncancerous cachexia and hypertrophic obesity. AT in GH-deficient adults displayed a substantial reduction of zinc-α2-glycoprotein. GH therapy normalized AT zinc-α2-glycoprotein. Obesity-related relative GH deficit was associated with almost 80% reduction of zinc-α2-glycoprotein mRNA in AT. GH increased zinc-α2-glycoprotein mRNA in both AT of obese men and primary human adipocytes. Interdependence of GH and zinc-α2-glycoprotein in regulating AT morphology and metabolic phenotype was evident from their relationship with adipocyte size and AT-specific and whole-body insulin sensitivity. The results demonstrate that GH is involved in regulation of AT zinc-α2-glycoprotein; however, the molecular mechanism linking GH and zinc-α2-glycoprotein in AT is yet unknown. © 2014 The Obesity Society.

Transport of radiolabelled glycoprotein to cell surface and lysosome-like bodies of absorptive cells in cultured small-intestinal tissue from normal subjects and patients with a lysosomal storage disease

International Nuclear Information System (INIS)

Ginsel, L.A.; Onderwater, J.J.M.; Daems, W.T.

1979-01-01

The transport of 3 H-fucose and 3 H-glucosamine-labelled glycoproteins in the absorptive cells of cultured human small-intestinal tissue was investigated with light- and electron-microscopical autoradiography. The findings showed that these glycoproteins were completed in the Golgi apparatus and transported in small vesicular structures to the apical cytoplasm of these cells. Since this material arrived in the cell coat on the microvilli and in the lysosome-like bodies simultaneously, a crinophagic function of these organelles in the regulation of the transport or secretion of cell-coat material was supported. In the absorptive cells of patients with fucosidosis or Hunter's type of lysosomal storage disease, a similar transport of cell-coat material to the lysosome-like bodies and a congenital defect of a lysosomal hydrolase normally involved in the degradation of cell-coat material, can explain the accumulation of this material in the dense bodies. (orig.) [de

Glycoprotein expression by adenomatous polyps of the colon

Science.gov (United States)

Roney, Celeste A.; Xie, Jianwu; Xu, Biying; Jabour, Paul; Griffiths, Gary; Summers, Ronald M.

2008-03-01

Colon cancer is the second leading cause of cancer related deaths in the United States. Specificity in diagnostic imaging for detecting colorectal adenomas, which have a propensity towards malignancy, is desired. Adenomatous polyp specimens of the colon were obtained from the mouse model of colorectal cancer called adenomatous polyposis coli-multiple intestinal neoplasia (APC Min). Histological evaluation, by the legume protein Ulex europaeus agglutinin I (UEA-1), determined expression of the glycoprotein α-L-fucose. FITC-labelled UEA-1 confirmed overexpression of the glycoprotein by the polyps on fluorescence microscopy in 17/17 cases, of which 13/17 included paraffin-fixed mouse polyp specimens. In addition, FITC-UEA-1 ex vivo multispectral optical imaging of 4/17 colonic specimens displayed over-expression of the glycoprotein by the polyps, as compared to non-neoplastic mucosa. Here, we report the surface expression of α-L-fucosyl terminal residues by neoplastic mucosal cells of APC specimens of the mouse. Glycoprotein expression was validated by the carbohydrate binding protein UEA-1. Future applications of this method are the development of agents used to diagnose cancers by biomedical imaging modalities, including computed tomographic colonography (CTC). UEA-1 targeting to colonic adenomas may provide a new avenue for the diagnosis of colorectal carcinoma by CT imaging.

Monoclonal antibody to an external epitope of the human mdr1 P-glycoprotein

NARCIS (Netherlands)

Arceci, R. J.; Stieglitz, K.; Bras, J.; Schinkel, A.; Baas, F.; Croop, J.

1993-01-01

A membrane glycoprotein, termed P-glycoprotein, has been shown to be responsible for cross-resistance to a broad range of structurally and functionally distinct cytotoxic agents. P-glycoprotein, encoded in humans by the mdr1 gene, functions as an energy-dependent efflux pump to exclude these

The stylar 120 kDa glycoprotein is required for S-specific pollen rejection in Nicotiana.

Science.gov (United States)

Hancock, C Nathan; Kent, Lia; McClure, Bruce A

2005-09-01

S-RNase participates in at least three mechanisms of pollen rejection. It functions in S-specific pollen rejection (self-incompatibility) and in at least two distinct interspecific mechanisms of pollen rejection in Nicotiana. S-specific pollen rejection and rejection of pollen from Nicotiana plumbaginifolia also require additional stylar proteins. Transmitting-tract-specific (TTS) protein, 120 kDa glycoprotein (120K) and pistil extensin-like protein III (PELP III) are stylar glycoproteins that bind S-RNase in vitro and are also known to interact with pollen. Here we tested whether these glycoproteins have a direct role in pollen rejection. 120K shows the most polymorphism in size between Nicotiana species. Larger 120K-like proteins are often correlated with S-specific pollen rejection. Sequencing results suggest that the polymorphism primarily reflects differences in glycosylation, although indels also occur in the predicted polypeptides. Using RNA interference (RNAi), we suppressed expression of 120K to determine if it is required for S-specific pollen rejection. Transgenic SC N. plumbaginifolia x SI Nicotiana alata (S105S105 or SC10SC10) hybrids with no detectable 120K were unable to perform S-specific pollen rejection. Thus, 120K has a direct role in S-specific pollen rejection. However, suppression of 120K had no effect on rejection of N. plumbaginifolia pollen. In contrast, suppression of HT-B, a factor previously implicated in S-specific pollen rejection, disrupts rejection of N. plumbaginifolia pollen. Thus, S-specific pollen rejection and rejection of N. plumbaginifolia pollen are mechanistically distinct, because they require different non-S-RNase factors.

Structures and Functions of Pestivirus Glycoproteins: Not Simply Surface Matters

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Fun-In Wang

2015-06-01

Full Text Available Pestiviruses, which include economically important animal pathogens such as bovine viral diarrhea virus and classical swine fever virus, possess three envelope glycoproteins, namely Erns, E1, and E2. This article discusses the structures and functions of these glycoproteins and their effects on viral pathogenicity in cells in culture and in animal hosts. E2 is the most important structural protein as it interacts with cell surface receptors that determine cell tropism and induces neutralizing antibody and cytotoxic T-lymphocyte responses. All three glycoproteins are involved in virus attachment and entry into target cells. E1-E2 heterodimers are essential for viral entry and infectivity. Erns is unique because it possesses intrinsic ribonuclease (RNase activity that can inhibit the production of type I interferons and assist in the development of persistent infections. These glycoproteins are localized to the virion surface; however, variations in amino acids and antigenic structures, disulfide bond formation, glycosylation, and RNase activity can ultimately affect the virulence of pestiviruses in animals. Along with mutations that are driven by selection pressure, antigenic differences in glycoproteins influence the efficacy of vaccines and determine the appropriateness of the vaccines that are currently being used in the field.

Importance of the short cytoplasmic domain of the feline immunodeficiency virus transmembrane glycoprotein for fusion activity and envelope glycoprotein incorporation into virions

International Nuclear Information System (INIS)

Celma, Cristina C.P.; Paladino, Monica G.; Gonzalez, Silvia A.; Affranchino, Jose L.

2007-01-01

The mature form of the envelope (Env) glycoprotein of lentiviruses is a heterodimer composed of the surface (SU) and transmembrane (TM) subunits. Feline immunodeficiency virus (FIV) possesses a TM glycoprotein with a cytoplasmic tail of approximately 53 amino acids which is unusually short compared with that of the other lentiviral glycoproteins (more than 100 residues). To investigate the relevance of the FIV TM cytoplasmic domain to Env-mediated viral functions, we characterized the biological properties of a series of Env glycoproteins progressively shortened from the carboxyl terminus. All the mutant Env proteins were efficiently expressed in feline cells and processed into the SU and TM subunits. Deletion of 5 or 11 amino acids from the TM C-terminus did not significantly affect Env surface expression, fusogenic activity or Env incorporation into virions, whereas removal of 17 or 23 residues impaired Env-mediated cell-to-cell fusion. Further truncation of the FIV TM by 29 residues resulted in an Env glycoprotein that was poorly expressed at the cell surface, exhibited only 20% of the wild-type Env fusogenic capacity and was inefficiently incorporated into virions. Remarkably, deletion of the TM C-terminal 35 or 41 amino acids restored or even enhanced Env biological functions. Indeed, these mutant Env glycoproteins bearing cytoplasmic domains of 18 or 12 amino acids were found to be significantly more fusogenic than the wild-type Env and were efficiently incorporated into virions. Interestingly, truncation of the TM cytoplasmic domain to only 6 amino acids did not affect Env incorporation into virions but abrogated Env fusogenicity. Finally, removal of the entire TM cytoplasmic tail or deletion of as many as 6 amino acids into the membrane-spanning domain led to a complete loss of Env functions. Our results demonstrate that despite its relatively short length, the FIV TM cytoplasmic domain plays an important role in modulating Env-mediated viral functions

Proteomic analysis of proteins secreted by the extra-embryonic membranes of the preimplantation sheep conceptus

International Nuclear Information System (INIS)

Lee, R.S.F.

2001-01-01

The extraembryonic membranes (EEM) of the preimplantation sheep conceptus play a major role in the supply of nutrition to the embryo and subsequently participate in the formation of the placentomes. Such functions are likely to be mediated by proteins secreted by the EEM. These proteins may mediate maternal-embryonic interactions or provide the embryo with essential nutrients during the period of early organogenesis and rapid growth and differentiation of the EEM, leading up to implantation. Large format (40 x 40 cm) 2-D gels were used to analyze proteins secreted by the trophoblast, allantois and the yolk sac of day 17 or 18 conceptuses after incubation separately for 3h in the presence of [ 35 S]-methionine. Hundreds of proteins were detected, many of which have not been identified. Each of these EEM secreted different compositions of proteins, as did the two cell layers of the trophoblast. Several proteins that were secreted by the trophectoderm were absent in proteins secreted by the mesoderm layer of the trophoblast. Two of those were identified as interferon-τ and aldose reductase. The proteins secreted by the yolk sac differed markedly from those secreted by the allantois even though both of these membranes were derived from endodermal and mesodermal lineages and are both vascularized. Many of the yolk sac secretory proteins were glycoproteins similar to those found in serum that are normally synthesized by the adult liver; one of these was identified as transferrin. Northern analysis showed that the transferrin mRNA in the yolk sac was even more abundant than it was in adult liver. The similarity between the set of proteins secreted by the yolk sac and those in serum that are attributable to the liver suggests that the yolk sac performs in part, the function of the liver in the synthesis of these proteins. Many proteins secreted by the trophoblast and yolk Sac were detectable in the allantoic fluid even though these membranes were not in contact with the

Quantitative mass spectrometric analysis of glycoproteins combined with enrichment methods.

Science.gov (United States)

Ahn, Yeong Hee; Kim, Jin Young; Yoo, Jong Shin

2015-01-01

Mass spectrometry (MS) has been a core technology for high sensitive and high-throughput analysis of the enriched glycoproteome in aspects of quantitative assays as well as qualitative profiling of glycoproteins. Because it has been widely recognized that aberrant glycosylation in a glycoprotein may involve in progression of a certain disease, the development of efficient analysis tool for the aberrant glycoproteins is very important for deep understanding about pathological function of the glycoprotein and new biomarker development. This review first describes the protein glycosylation-targeting enrichment technologies mainly employing solid-phase extraction methods such as hydrizide-capturing, lectin-specific capturing, and affinity separation techniques based on porous graphitized carbon, hydrophilic interaction chromatography, or immobilized boronic acid. Second, MS-based quantitative analysis strategies coupled with the protein glycosylation-targeting enrichment technologies, by using a label-free MS, stable isotope-labeling, or targeted multiple reaction monitoring (MRM) MS, are summarized with recent published studies. © 2014 The Authors. Mass Spectrometry Reviews Published by Wiley Periodicals, Inc.

A Method for Determining the Content of Glycoproteins in Biological Samples

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Yang Gao

2016-11-01

Full Text Available The glycoprotein purified from the mycelium extract of Tremella fuciformis was marked with iodine through the iodine substitution reaction. The content of iodine, which is indicative of the amount of the marked tremella glycoprotein (ITG, was detected with Inductively coupled plasma mass spectrometry (ICP-MS. The method was found to be stable, sensitive, and accurate at detecting the content of iodine-substituted glycoprotein, and was used in the quantitative analysis of biological samples, including blood and organs. Different biological samples were collected from rats after oral administration of ITG, and were tested for iodine content by ICP-MS to calculate the amount of ITG in the samples. The results suggested that ICP-MS is a sensitive, stable, and accurate method for detection of iodinated glycoproteins in blood and organs.

High level expression and secretion of truncated forms of herpes simplex virus type I and type 2 glycoprotein D by the methylotrophic yeast Pichia pastoris

NARCIS (Netherlands)

van Kooij, A; Middel, J; Jakab, F; Elfferich, P; Koedijk, DGAM; Feijlbrief, M; Scheffer, AJ; Degener, JE; The, TH; Scheek, RM; Welling, GW; Welling-Wester, S

Herpes simplex virus type I and 2 (HSV-1 and -2) glycoproteins D (gD-1 and gD-2) play a role in the entry of the virus into the host cell. Availability of substantial amounts of these proteins, or large fragments thereof. will he needed to allow studies at the molecular level. We studied the potency

Glycoprotein of the wall of sycamore tissue-culture cells.

Science.gov (United States)

Heath, M F; Northcote, D H

1971-12-01

1. A glycoprotein containing a large amount of hydroxyproline is present in the cell walls of sycamore callus cells. This protein is insoluble and remained in the alpha-cellulose when a mild separation procedure was used to obtain the polysaccharide fractions of the wall. The glycoprotein contained a high proportion of arabinose and galactose. 2. Soluble glycopeptides were prepared from the alpha-cellulose fraction when peptide bonds were broken by hydrazinolysis. The soluble material was fractionated by gel filtration and one glycopeptide was further purified by electrophoresis; it had a composition of 10% hydroxyproline, 35% arabinose and 55% galactose, and each hydroxyproline residue carried a glycosyl radical so that the oligosaccharides on the glycopeptide had an average degree of polymerization of 9. 3. The extraction of the glycopeptides was achieved without cleavage of glycosyl bonds, so that the glycoprotein cannot act as a covalent cross-link between the major polysaccharides of the wall. 4. The wall protein approximates in conformation to polyhydroxyproline and therefore it probably has similar physicochemical properties to polyhydroxyproline. This is discussed in relation to the function of the glycoprotein and its effect on the physical and chemical nature of the wall.

The macrophage CD163 surface glycoprotein is an erythroblast adhesion receptor

DEFF Research Database (Denmark)

Fabriek, Babs O; Polfliet, Machteld M J; Vloet, Rianka P M

2007-01-01

Erythropoiesis occurs in erythroblastic islands, where developing erythroblasts closely interact with macrophages. The adhesion molecules that govern macrophage-erythroblast contact have only been partially defined. Our previous work has implicated the rat ED2 antigen, which is highly expressed...... on the surface of macrophages in erythroblastic islands, in erythroblast binding. In particular, the monoclonal antibody ED2 was found to inhibit erythroblast binding to bone marrow macrophages. Here, we identify the ED2 antigen as the rat CD163 surface glycoprotein, a member of the group B scavenger receptor...... that it enhanced erythroid proliferation and/or survival, but did not affect differentiation. These findings identify CD163 on macrophages as an adhesion receptor for erythroblasts in erythroblastic islands, and suggest a regulatory role for CD163 during erythropoiesis....

Global identification of prokaryotic glycoproteins based on an Escherichia coli proteome microarray.

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Zong-Xiu Wang

Full Text Available Glycosylation is one of the most abundant protein posttranslational modifications. Protein glycosylation plays important roles not only in eukaryotes but also in prokaryotes. To further understand the roles of protein glycosylation in prokaryotes, we developed a lectin binding assay to screen glycoproteins on an Escherichia coli proteome microarray containing 4,256 affinity-purified E.coli proteins. Twenty-three E.coli proteins that bound Wheat-Germ Agglutinin (WGA were identified. PANTHER protein classification analysis showed that these glycoprotein candidates were highly enriched in metabolic process and catalytic activity classes. One sub-network centered on deoxyribonuclease I (sbcB was identified. Bioinformatics analysis suggests that prokaryotic protein glycosylation may play roles in nucleotide and nucleic acid metabolism. Fifteen of the 23 glycoprotein candidates were validated by lectin (WGA staining, thereby increasing the number of validated E. coli glycoproteins from 3 to 18. By cataloguing glycoproteins in E.coli, our study greatly extends our understanding of protein glycosylation in prokaryotes.

Thyroid hormone upregulates zinc-α2-glycoprotein production in the liver but not in adipose tissue.

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Rafael Simó

Full Text Available Overproduction of zinc-α2-glycoprotein by adipose tissue is crucial in accounting for the lipolysis occurring in cancer cachexia of certain malignant tumors. The main aim of this study was to explore whether thyroid hormone could enhance zinc-α2-glycoprotein production in adipose tissue. In addition, the regulation of zinc-α2-glycoprotein by thyroid hormone in the liver was investigated. We performed in vitro (HepG2 cells and primary human adipocytes and in vivo (C57BL6/mice experiments addressed to examine the effect of thyroid hormone on zinc-α2-glycoprotein production (mRNA and protein levels in liver and visceral adipose tissue. We also measured the zinc-α2-glycoprotein serum levels in a cohort of patients before and after controlling their hyperthyroidism. Our results showed that thyroid hormone up-regulates zinc-α2-glycoprotein production in HepG2 cells in a dose-dependent manner. In addition, the zinc-α2-glycoprotein proximal promoter contains functional thyroid hormone receptor binding sites that respond to thyroid hormone treatment in luciferase reporter gene assays in HepG2 cells. Furthermore, zinc-α2-glycoprotein induced lipolysis in HepG2 in a dose-dependent manner. Our in vivo experiments in mice confirmed the up-regulation of zinc-α2-glycoprotein induced by thyroid hormone in the liver, thus leading to a significant increase in zinc-α2-glycoprotein circulating levels. However, thyroid hormone did not regulate zinc-α2-glycoprotein production in either human or mouse adipocytes. Finally, in patients with hyperthyroidism a significant reduction of zinc-α2-glycoprotein serum levels was detected after treatment but was unrelated to body weight changes. We conclude that thyroid hormone up-regulates the production of zinc-α2-glycoprotein in the liver but not in the adipose tissue. The neutral effect of thyroid hormones on zinc-α2-glycoprotein expression in adipose tissue could be the reason why zinc-α2-glycoprotein is not

Thyroid hormone upregulates zinc-α2-glycoprotein production in the liver but not in adipose tissue.

Science.gov (United States)

Simó, Rafael; Hernández, Cristina; Sáez-López, Cristina; Soldevila, Berta; Puig-Domingo, Manel; Selva, David M

2014-01-01

Overproduction of zinc-α2-glycoprotein by adipose tissue is crucial in accounting for the lipolysis occurring in cancer cachexia of certain malignant tumors. The main aim of this study was to explore whether thyroid hormone could enhance zinc-α2-glycoprotein production in adipose tissue. In addition, the regulation of zinc-α2-glycoprotein by thyroid hormone in the liver was investigated. We performed in vitro (HepG2 cells and primary human adipocytes) and in vivo (C57BL6/mice) experiments addressed to examine the effect of thyroid hormone on zinc-α2-glycoprotein production (mRNA and protein levels) in liver and visceral adipose tissue. We also measured the zinc-α2-glycoprotein serum levels in a cohort of patients before and after controlling their hyperthyroidism. Our results showed that thyroid hormone up-regulates zinc-α2-glycoprotein production in HepG2 cells in a dose-dependent manner. In addition, the zinc-α2-glycoprotein proximal promoter contains functional thyroid hormone receptor binding sites that respond to thyroid hormone treatment in luciferase reporter gene assays in HepG2 cells. Furthermore, zinc-α2-glycoprotein induced lipolysis in HepG2 in a dose-dependent manner. Our in vivo experiments in mice confirmed the up-regulation of zinc-α2-glycoprotein induced by thyroid hormone in the liver, thus leading to a significant increase in zinc-α2-glycoprotein circulating levels. However, thyroid hormone did not regulate zinc-α2-glycoprotein production in either human or mouse adipocytes. Finally, in patients with hyperthyroidism a significant reduction of zinc-α2-glycoprotein serum levels was detected after treatment but was unrelated to body weight changes. We conclude that thyroid hormone up-regulates the production of zinc-α2-glycoprotein in the liver but not in the adipose tissue. The neutral effect of thyroid hormones on zinc-α2-glycoprotein expression in adipose tissue could be the reason why zinc-α2-glycoprotein is not related to weight

A protein secretion system linked to bacteroidete gliding motility and pathogenesis

Science.gov (United States)

Sato, Keiko; Naito, Mariko; Yukitake, Hideharu; Hirakawa, Hideki; Shoji, Mikio; McBride, Mark J.; Rhodes, Ryan G.; Nakayama, Koji

2009-01-01

Porphyromonas gingivalis secretes strong proteases called gingipains that are implicated in periodontal pathogenesis. Protein secretion systems common to other Gram-negative bacteria are lacking in P. gingivalis, but several proteins, including PorT, have been linked to gingipain secretion. Comparative genome analysis and genetic experiments revealed 11 additional proteins involved in gingipain secretion. Six of these (PorK, PorL, PorM, PorN, PorW, and Sov) were similar in sequence to Flavobacterium johnsoniae gliding motility proteins, and two others (PorX and PorY) were putative two-component system regulatory proteins. Real-time RT-PCR analysis revealed that porK, porL, porM, porN, porP, porT, and sov were down-regulated in P. gingivalis porX and porY mutants. Disruption of the F. johnsoniae porT ortholog resulted in defects in motility, chitinase secretion, and translocation of a gliding motility protein, SprB adhesin, to the cell surface, providing a link between a unique protein translocation system and a motility apparatus in members of the Bacteroidetes phylum. PMID:19966289

3,3′,4,4′,5-Pentachlorobiphenyl Inhibits Drug Efflux Through P-Glycoprotein in KB-3 Cells Expressing Mutant Human P-Glycoprotein

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Hiroshi Fujise

2004-01-01

Full Text Available The effects on the drug efflux of 3,3′,4,4′,5-pentachlorobiphenyl (PCB-126, the most toxic of all coplanar polychlorinated biphenyls (Co-PCBs, were examined in KB-3 cells expressing human wild-type and mutant P-glycoprotein in which the 61st amino acid was substituted for serine or phenylalanine (KB3-Phe61. In the cells expressing P-glycoproteins, accumulations of vinblastine and colchicine decreased form 85% to 92% and from 62% to 91%, respectively, and the drug tolerances for these chemicals were increased. In KB3-Phe61, the decreases in drug accumulation were inhibited by adding PCB-126 in a way similar to that with cyclosporine A: by adding 1 μM PCB-126, the accumulations of vinblastine and colchicine increased up to 3.3- and 2.3-fold, respectively. It is suggested that PCB-126 decreased the drug efflux by inhibiting the P-glycoprotein in KB3-Phe61. Since there were various P-glycoproteins and many congeners of Co-PCBs, this inhibition has to be considered a new cause of the toxic effects of Co-PCBs.

Raman optical activity of proteins and glycoproteins

International Nuclear Information System (INIS)

Smyth, E.

2000-03-01

Raman optical activity (ROA), measured in this project as a small difference in the intensity of Raman scattering from chiral molecules in right- and left-circularly polarised incident laser light, offers the potential to provide more information about the structure of biological molecules in aqueous solution than conventional spectroscopic techniques. Chapter one contains a general discussion of the relative merits of different spectroscopic techniques for structure determination of biomolecules, as well as a brief introduction to ROA. In Chapter two a theoretical analysis of ROA is developed, which extends the discussion in chapter one. The spectrometer setup and sample preparation is then discussed in chapter three. Instrument and sample conditions are monitored to ensure that the best results are obtained. As with any experimental project problems occur, which may result in a degradation of the spectra obtained. The cause of these problems was explored and remedied whenever possible. Chapter four introduces a brief account of protein, glycoprotein and carbohydrate structure and function, with a particular emphasis on the structure of proteins. In the remaining chapters experimental ROA results on proteins and glycoproteins, with some carbohydrate samples, from a wide range of sources are examined. For example, in chapter five some β-sheet proteins are examined. Structural features in these proteins are examined in the extended amide III region of their ROA spectra, revealing that ROA is sensitive to the rigidity or flexibility inherent in proteins. Chapter six concentrates on a group of proteins (usually glycoproteins) known as the serine proteinase inhibitors (serpins). Medically, the serpins are one of the most important groups of proteins of current interest, with wide-ranging implications in conditions such as Down's syndrome, Alzheimer's disease, and emphysema with associated cirrhosis of the liver. With favourable samples and conditions ROA may offer the

The Secret of Intrafamilial Child Sexual Abuse: Who Keeps It and How?

Science.gov (United States)

Tener, Dafna

2018-01-01

This article analyzes how women survivors of intrafamilial child sexual abuse perceive the family members who took part in keeping it secret and their tactics for doing so. Analysis of 20 in-depth interviews with Jewish Israeli women revealed unique ways of guarding the secret. These were attributed to the perpetrator, the mother and the family. Secret-keeping tactics included presenting a normative public identity or an unstable psychological identity, presenting multiple personas, reframing the abuse, concealing any trace of the secret after it was disclosed, as if the abuse had never happened, and making a monument of the abuser. These tactics are discussed in the context of silencing, the interpersonal relations orientation model, and the wider concepts of secrecy in society. Implications for professional practice and for society are considered, and new attitudes toward intrafamilial child sexual abuse secrecy are suggested.

Glycoprotein and proteoglycan techniques

International Nuclear Information System (INIS)

Beeley, J.G.

1985-01-01

The aim of this book is to describe techniques which can be used to answer some of the basic questions about glycosylated proteins. Methods are discussed for isolation, compositional analysis, and for determination of the primary structure of carbohydrate units and the nature of protein-carbohydrate linkages of glycoproteins and proteoglycans. High resolution NMR is considered, as well as radioactive labelling techniques. (Auth.)

HIV-1 envelope glycoprotein

Science.gov (United States)

Caulfield, Michael; Cupo, Albert; Dean, Hansi; Hoffenberg, Simon; King, C. Richter; Klasse, P. J.; Marozsan, Andre; Moore, John P.; Sanders, Rogier W.; Ward, Andrew; Wilson, Ian; Julien, Jean-Philippe

2017-08-22

The present application relates to novel HIV-1 envelope glycoproteins, which may be utilized as HIV-1 vaccine immunogens, and antigens for crystallization, electron microscopy and other biophysical, biochemical and immunological studies for the identification of broad neutralizing antibodies. The present invention encompasses the preparation and purification of immunogenic compositions, which are formulated into the vaccines of the present invention.

Open Secrets

OpenAIRE

Madison, Michael

2017-01-01

The law of trade secrets is often conceptualized in bilateral terms, as creating and enforcing rights between trade secret owners, on the one hand, and misappropriators on the other hand. This paper, a chapter in a forthcoming collection on the law of trade secrets, argues that trade secrets and the law that guards them can serve structural and insitutional roles as well. Somewhat surprisingly, given the law’s focus on secrecy, among the institutional products of trade secrets law are commons...

Extracellular vesicles secreted from cancer cell lines stimulate secretion of MMP-9, IL-6, TGF-β1 and EMMPRIN.

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Jasmina S Redzic

Full Text Available Extracellular vesicles (EVs are key contributors to cancer where they play an integral role in cell-cell communication and transfer pro-oncogenic molecules to recipient cells thereby conferring a cancerous phenotype. Here, we purified EVs using straightforward biochemical approaches from multiple cancer cell lines and subsequently characterized these EVs via multiple biochemical and biophysical methods. In addition, we used fluorescence microscopy to directly show internalization of EVs into the recipient cells within a few minutes upon addition of EVs to recipient cells. We confirmed that the transmembrane protein EMMPRIN, postulated to be a marker of EVs, was indeed secreted from all cell lines studied here. We evaluated the response to EV stimulation in several different types of recipient cells lines and measured the ability of these purified EVs to induce secretion of several factors highly upregulated in human cancers. Our data indicate that purified EVs preferentially stimulate secretion of several proteins implicated in driving cancer in monocytic cells but only harbor limited activity in epithelial cells. Specifically, we show that EVs are potent stimulators of MMP-9, IL-6, TGF-β1 and induce the secretion of extracellular EMMPRIN, which all play a role in driving immune evasion, invasion and inflammation in the tumor microenvironment. Thus, by using a comprehensive approach that includes biochemical, biological, and spectroscopic methods, we have begun to elucidate the stimulatory roles.

The NS1 glycoprotein can generate dramatic antibody-enhanced dengue viral replication in normal out-bred mice resulting in lethal multi-organ disease.

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Andrew K I Falconar

Full Text Available Antibody-enhanced replication (AER of dengue type-2 virus (DENV-2 strains and production of antibody-enhanced disease (AED was tested in out-bred mice. Polyclonal antibodies (PAbs generated against the nonstructural-1 (NS1 glycoprotein candidate vaccine of the New Guinea-C (NG-C or NSx strains reacted strongly and weakly with these antigens, respectively. These PAbs contained the IgG2a subclass, which cross-reacted with the virion-associated envelope (E glycoprotein of the DENV-2 NSx strain, suggesting that they could generate its AER via all mouse Fcγ-receptor classes. Indeed, when these mice were challenged with a low dose (<0.5 LD₅₀ of the DENV-2 NSx strain, but not the NG-C strain, they all generated dramatic and lethal DENV-2 AER/AED. These AER/AED mice developed life-threatening acute respiratory distress syndrome (ARDS, displayed by diffuse alveolar damage (DAD resulting from i dramatic interstitial alveolar septa-thickening with mononuclear cells, ii some hyperplasia of alveolar type-II pneumocytes, iii copious intra-alveolar protein secretion, iv some hyaline membrane-covered alveolar walls, and v DENV-2 antigen-positive alveolar macrophages. These mice also developed meningo-encephalitis, with greater than 90,000-fold DENV-2 AER titers in microglial cells located throughout their brain parenchyma, some of which formed nodules around dead neurons. Their spleens contained infiltrated megakaryocytes with DENV-2 antigen-positive red-pulp macrophages, while their livers displayed extensive necrosis, apoptosis and macro- and micro-steatosis, with DENV-2 antigen-positive Kuppfer cells and hepatocytes. Their infections were confirmed by DENV-2 isolations from their lungs, spleens and livers. These findings accord with those reported in fatal human "severe dengue" cases. This DENV-2 AER/AED was blocked by high concentrations of only the NG-C NS1 glycoprotein. These results imply a potential hazard of DENV NS1 glycoprotein-based vaccines

Crystallization and preliminary X-ray analysis of Chandipura virus glycoprotein G

International Nuclear Information System (INIS)

Baquero, Eduard; Buonocore, Linda; Rose, John K.; Bressanelli, Stéphane; Gaudin, Yves; Albertini, Aurélie A.

2012-01-01

Chandipura virus glycoprotein ectodomain (Gth) was purified and crystallized at pH 7.5. X-ray diffraction data set was collected to a resolution of 3.1 Å. Fusion in members of the Rhabdoviridae virus family is mediated by the G glycoprotein. At low pH, the G glycoprotein catalyzes fusion between viral and endosomal membranes by undergoing a major conformational change from a pre-fusion trimer to a post-fusion trimer. The structure of the G glycoprotein from vesicular stomatitis virus (VSV G), the prototype of Vesiculovirus, has recently been solved in its trimeric pre-fusion and post-fusion conformations; however, little is known about the structural details of the transition. In this work, a soluble form of the ectodomain of Chandipura virus G glycoprotein (CHAV G th ) was purified using limited proteolysis of purified virus; this soluble ectodomain was also crystallized. This protein shares 41% amino-acid identity with VSV G and thus its structure could provide further clues about the structural transition of rhabdoviral glycoproteins induced by low pH. Crystals of CHAV G th obtained at pH 7.5 diffracted X-rays to 3.1 Å resolution. These crystals belonged to the orthorhombic space group P2 1 2 1 2, with unit-cell parameters a = 150.3, b = 228.2, c = 78.8 Å. Preliminary analysis of the data based on the space group and the self-rotation function indicated that there was no trimeric association of the protomers. This unusual oligomeric status could result from the presence of fusion intermediates in the crystal

Expression of bovine herpesvirus 1 glycoproteins gI and gIII in transfected murine cells

International Nuclear Information System (INIS)

Fitzpatrick, D.R.; Zamb, T.; Parker, M.D.; van Drunen Littel-van den Hurk, S.; Babiuk, L.A.; Lawman, M.J.P.

1988-01-01

Genes encoding two of the major glycoproteins of bovine herpesvirus 1 (BHV-1), gI and gIII, were cloned into the eucaryotic expression vectors pRSVcat and pSV2neo and transfected into murine LMTK - cells, and cloned cell lines were established. The relative amounts of gI or gIII expressed from the two vectors were similar. Expression of gI was cell associated and localized predominantly in the perinuclear region, but nuclear and plasma membrane staining was also observed. Expression of gI was additionally associated with cell fusion and the formation of polykaryons and giant cells. Expression of gIII was localized predominantly in the nuclear and plasma membranes. Radioimmunoprecipitation in the presence or absence of tunicamycin revealed that the recombinant glycoproteins were proteolytically processed and glycosylated and had molecular weights similar to those of the forms of gI and gIII expressed in BHV-1 infected bovine cells. However, both recombinant glycoproteins were glycosylated to a lesser extent than were the forms found in BHV-1 infected bovine cells. For gI, a deficiency in N-linked glycosylated of the amino-terminal half of the protein was identified; for gIII, a deficiency in O-linked glycosylation was implicated. The reactivity pattern of a panel of gI- and gIII-specific monoclonal antibodies, including six which recognize conformation-dependent epitopes, was found to be unaffected by the glycosylation differences and was identical for transfected of BHV-1-infected murine cells. Use of the transfected cells as targets in immune-mediated cytotoxicity assays demonstrated the functional recognition of recombinant gI and gIII by murine antibody and cytotoxic T lymphocytes

Synthetic glycopeptides and glycoproteins with applications in biological research

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Ulrika Westerlind

2012-05-01

Full Text Available Over the past few years, synthetic methods for the preparation of complex glycopeptides have been drastically improved. The need for homogenous glycopeptides and glycoproteins with defined chemical structures to study diverse biological phenomena further enhances the development of methodologies. Selected recent advances in synthesis and applications, in which glycopeptides or glycoproteins serve as tools for biological studies, are reviewed. The importance of specific antibodies directed to the glycan part, as well as the peptide backbone has been realized during the development of synthetic glycopeptide-based anti-tumor vaccines. The fine-tuning of native chemical ligation (NCL, expressed protein ligation (EPL, and chemoenzymatic glycosylation techniques have all together enabled the synthesis of functional glycoproteins. The synthesis of structurally defined, complex glycopeptides or glyco-clusters presented on natural peptide backbones, or mimics thereof, offer further possibilities to study protein-binding events.

Three-dimensionally Functionalized Reverse Phase Glycoprotein Array for Cancer Biomarker Discovery and Validation

OpenAIRE

Pan, Li; Aguilar, Hillary Andaluz; Wang, Linna; Iliuk, Anton; Tao, W. Andy

2016-01-01

Glycoproteins have vast structural diversity which plays an important role in many biological processes and have great potential as disease biomarkers. Here we report a novel functionalized reverse phase protein array (RPPA), termed polymer-based reverse phase GlycoProtein Array (polyGPA), to specifically capture and profile glycoproteomes, and validate glycoproteins. Nitrocellulose membrane functionalized with globular hydroxyaminodendrimers was used to covalently capture pre-oxidized glycan...

Proteomic Identification of Novel Secreted Antibacterial Toxins of the Serratia marcescens Type VI Secretion System*

Science.gov (United States)

Fritsch, Maximilian J.; Trunk, Katharina; Diniz, Juliana Alcoforado; Guo, Manman; Trost, Matthias; Coulthurst, Sarah J.

2013-01-01

It has recently become apparent that the Type VI secretion system (T6SS) is a complex macromolecular machine used by many bacterial species to inject effector proteins into eukaryotic or bacterial cells, with significant implications for virulence and interbacterial competition. “Antibacterial” T6SSs, such as the one elaborated by the opportunistic human pathogen, Serratia marcescens, confer on the secreting bacterium the ability to rapidly and efficiently kill rival bacteria. Identification of secreted substrates of the T6SS is critical to understanding its role and ability to kill other cells, but only a limited number of effectors have been reported so far. Here we report the successful use of label-free quantitative mass spectrometry to identify at least eleven substrates of the S. marcescens T6SS, including four novel effector proteins which are distinct from other T6SS-secreted proteins reported to date. These new effectors were confirmed as antibacterial toxins and self-protecting immunity proteins able to neutralize their cognate toxins were identified. The global secretomic study also unexpectedly revealed that protein phosphorylation-based post-translational regulation of the S. marcescens T6SS differs from that of the paradigm, H1-T6SS of Pseudomonas aeruginosa. Combined phosphoproteomic and genetic analyses demonstrated that conserved PpkA-dependent threonine phosphorylation of the T6SS structural component Fha is required for T6SS activation in S. marcescens and that the phosphatase PppA can reverse this modification. However, the signal and mechanism of PpkA activation is distinct from that observed previously and does not appear to require cell–cell contact. Hence this study has not only demonstrated that new and species-specific portfolios of antibacterial effectors are secreted by the T6SS, but also shown for the first time that PpkA-dependent post-translational regulation of the T6SS is tailored to fit the needs of different bacterial

CD109 is a component of exosome secreted from cultured cells

International Nuclear Information System (INIS)

Sakakura, Hiroki; Mii, Shinji; Hagiwara, Sumitaka; Kato, Takuya; Yamamoto, Noriyuki; Hibi, Hideharu; Takahashi, Masahide; Murakumo, Yoshiki

2016-01-01

Exosomes are 50–100-nm-diameter membrane vesicles released from various types of cells. Exosomes retain proteins, mRNAs and miRNAs, which can be transported to surrounding cells. CD109 is a glycosylphosphatidylinositol-anchored glycoprotein, and is released from the cell surface to the culture medium in vitro. Recently, it was reported that secreted CD109 from the cell surface downregulates transforming growth factor-β signaling in human keratinocytes. In this study, we revealed that CD109 is a component of the exosome in conditioned medium. FLAG-tagged human CD109 (FLAG-CD109) in conditioned medium secreted from HEK293 cells expressing FLAG-CD109 (293/FLAG-CD109) was immunoprecipitated with anti-FLAG affinity gel, and the co-precipitated proteins were analyzed by mass spectrometry and western blotting. Exosomal proteins were associated with CD109. We revealed the presence of CD109 in exosome fractions from conditioned medium of 293/FLAG-CD109. Moreover, the localization of CD109 in the exosome was demonstrated using immuno-electron microscopy. When we used HEK293 cells expressing FLAG-tagged truncated CD109, which does not contain the C-terminal region, the association of truncated CD109 with exosomes was not detected in conditioned medium. These findings indicate that CD109 is an exosomal protein and that the C-terminal region of CD109 is required for its presence in the exosome. - Highlights: • CD109 is an exosomal protein. • The C-terminal region of CD109 is required for its presence in the exosome. • Part of the secreted CD109 is present in the exosome-free fraction in the conditioned medium.

CD109 is a component of exosome secreted from cultured cells

Energy Technology Data Exchange (ETDEWEB)

Sakakura, Hiroki [Department of Pathology, Nagoya University Graduate School of Medicine, Nagoya (Japan); Department of Oral and Maxillofacial Surgery, Nagoya University Graduate School of Medicine, Nagoya (Japan); Mii, Shinji [Department of Pathology, Nagoya University Graduate School of Medicine, Nagoya (Japan); Hagiwara, Sumitaka [Department of Oral and Maxillofacial Surgery, Nagoya University Graduate School of Medicine, Nagoya (Japan); Department of Head and Neck Surgery, Aichi Cancer Center Hospital, Nagoya (Japan); Kato, Takuya [Department of Pathology, Nagoya University Graduate School of Medicine, Nagoya (Japan); Yamamoto, Noriyuki; Hibi, Hideharu [Department of Oral and Maxillofacial Surgery, Nagoya University Graduate School of Medicine, Nagoya (Japan); Takahashi, Masahide, E-mail: mtakaha@med.nagoya-u.ac.jp [Department of Pathology, Nagoya University Graduate School of Medicine, Nagoya (Japan); Murakumo, Yoshiki, E-mail: murakumo@med.kitasato-u.ac.jp [Department of Pathology, Nagoya University Graduate School of Medicine, Nagoya (Japan); Department of Pathology, Kitasato University School of Medicine, Sagamihara, Kanagawa (Japan)

2016-01-22

Exosomes are 50–100-nm-diameter membrane vesicles released from various types of cells. Exosomes retain proteins, mRNAs and miRNAs, which can be transported to surrounding cells. CD109 is a glycosylphosphatidylinositol-anchored glycoprotein, and is released from the cell surface to the culture medium in vitro. Recently, it was reported that secreted CD109 from the cell surface downregulates transforming growth factor-β signaling in human keratinocytes. In this study, we revealed that CD109 is a component of the exosome in conditioned medium. FLAG-tagged human CD109 (FLAG-CD109) in conditioned medium secreted from HEK293 cells expressing FLAG-CD109 (293/FLAG-CD109) was immunoprecipitated with anti-FLAG affinity gel, and the co-precipitated proteins were analyzed by mass spectrometry and western blotting. Exosomal proteins were associated with CD109. We revealed the presence of CD109 in exosome fractions from conditioned medium of 293/FLAG-CD109. Moreover, the localization of CD109 in the exosome was demonstrated using immuno-electron microscopy. When we used HEK293 cells expressing FLAG-tagged truncated CD109, which does not contain the C-terminal region, the association of truncated CD109 with exosomes was not detected in conditioned medium. These findings indicate that CD109 is an exosomal protein and that the C-terminal region of CD109 is required for its presence in the exosome. - Highlights: • CD109 is an exosomal protein. • The C-terminal region of CD109 is required for its presence in the exosome. • Part of the secreted CD109 is present in the exosome-free fraction in the conditioned medium.

Filamentous fungi as production organisms for glycoproteins of bio-medical interest

NARCIS (Netherlands)

Maras, M.; Die, I. van; Contreras, R.; Hondel, C.A.M.J.J. van den

1999-01-01

Filamentous fungi are commonly used in the fermentation industry for large scale production of glycoproteins. Several of these proteins can be produced in concentrations up to 20-40 g per litre. The production of heterologous glycoproteins is at least one or two orders of magnitude lower but

Porphyromonas gingivalis and related bacteria: from colonial pigmentation to the type IX secretion system and gliding motility

Science.gov (United States)

Nakayama, K

2015-01-01

Porphyromonas gingivalis is a gram-negative, non-motile, anaerobic bacterium implicated as a major pathogen in periodontal disease. P. gingivalis grows as black-pigmented colonies on blood agar, and many bacteriologists have shown interest in this property. Studies of colonial pigmentation have revealed a number of important findings, including an association with the highly active extracellular and surface proteinases called gingipains that are found in P. gingivalis. The Por secretion system, a novel type IX secretion system (T9SS), has been implicated in gingipain secretion in studies using non-pigmented mutants. In addition, many potent virulence proteins, including the metallocarboxypeptidase CPG70, 35 kDa hemin-binding protein HBP35, peptidylarginine deiminase PAD and Lys-specific serine endopeptidase PepK, are secreted through the T9SS. These findings have not been limited to P. gingivalis but have been extended to other bacteria belonging to the phylum Bacteroidetes. Many Bacteroidetes species possess the T9SS, which is associated with gliding motility for some of these bacteria. PMID:25546073

Co-treatment by docetaxel and vinblastine breaks down P-glycoprotein mediated chemo-resistance

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Mahsa Mohseni

2016-03-01

Results: Combination treatment of the cells with docetaxel and vinblastine decreased the IC50 values for docetaxel from (30±3.1 to (15±2.6 nM and for vinblastine from (30±5.9 to (5±5.6 nM (P≤0.05.               P-glycoprotein mRNA expression level showed a significant up-regulation in the cells incubated with each drug alone (P≤0.001. Incubation of the cells with combined concentrations of both agents neutralized P-glycoprotein overexpression (P≤0.05. Adding verapamil, a P-glycoprotein inhibitor caused a further increase in the percentage of apoptotic cells when the cells were treated with both agents.  Conclusion:Our results suggest that combination therapy along with P-glycoprotein inhibition can be considered as a novel approach to improve the efficacy of chemotherapeutics in cancer patients with high P-glycoprotein expression.

Evaluation of electrical aggregometry: comparison with optical aggregometry, secretion of ATP, and accumulation of radiolabeled platelets

International Nuclear Information System (INIS)

Ingerman-Wojenski, C.; Smith, J.B.; Silver, M.J.

1983-01-01

Platelet aggregation has been most commonly studied in vitro by measuring increases in light transmission as platelets aggregate in PRP. Recently, an electrical impedance method for measuring platelet aggregation has been introduced. This method can be used with either PRP or whole blood and measures an increase in impedance across electrodes placed in the blood samples as platelets accumulate on them. We have compared the results obtained by the two methods, using ADP and collagen as aggregating agents, and also have measured the secretion of platelet ATP simultaneously. Although the aggregometry results were similar, recordings obtained by the electrical method did not distinguish two waves of platelet aggregation or correlate with secretion as well as recordings obtained by the optical method. When PGI2 or PGE1 was added to the PRP, both the rate and extent of the increase in light transmittance were inhibited, but the main effect on the increase in impedance was a decrease in its rate and not in its extent. Increases in impedance and secretion of ATP were also measured in whole blood after the platelets had been labeled with a 125 I-containing antibody specific for platelet surface glycoproteins. It appeared that the increases in impedance lagged several minutes behind the formation of platelet aggregates and the secretion of platelet ATP. It is suggested that there are advantages and disadvantages to both methods of measurement of platelet aggregation and that the parameters being measured must be clearly understood to properly interpret the results

Molecular model of a type III secretion system needle: Implications for host-cell sensing.

Science.gov (United States)

Deane, Janet E; Roversi, Pietro; Cordes, Frank S; Johnson, Steven; Kenjale, Roma; Daniell, Sarah; Booy, Frank; Picking, William D; Picking, Wendy L; Blocker, Ariel J; Lea, Susan M

2006-08-15

Type III secretion systems are essential virulence determinants for many Gram-negative bacterial pathogens. The type III secretion system consists of cytoplasmic, transmembrane, and extracellular domains. The extracellular domain is a hollow needle protruding above the bacterial surface and is held within a basal body that traverses both bacterial membranes. Effector proteins are translocated, via this external needle, directly into host cells, where they subvert normal cell functions to aid infection. Physical contact with host cells initiates secretion and leads to formation of a pore, thought to be contiguous with the needle channel, in the host-cell membrane. Here, we report the crystal structure of the Shigella flexneri needle subunit MxiH and a complete model for the needle assembly built into our three-dimensional EM reconstruction. The model, combined with mutagenesis data, reveals that signaling of host-cell contact is relayed through the needle via intersubunit contacts and suggests a mode of binding for a tip complex.

Biochemical characterization and comparison of aspartylglucosaminidases secreted in venom of the parasitoid wasps Asobara tabida and Leptopilina heterotoma.

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Quentin Coulette

Full Text Available Aspartylglucosaminidase (AGA is a low-abundance intracellular enzyme that plays a key role in the last stage of glycoproteins degradation, and whose deficiency leads to human aspartylglucosaminuria, a lysosomal storage disease. Surprisingly, high amounts of AGA-like proteins are secreted in the venom of two phylogenetically distant hymenopteran parasitoid wasp species, Asobara tabida (Braconidae and Leptopilina heterotoma (Cynipidae. These venom AGAs have a similar domain organization as mammalian AGAs. They share with them key residues for autocatalysis and activity, and the mature α- and β-subunits also form an (αβ2 structure in solution. Interestingly, only one of these AGAs subunits (α for AtAGA and β for LhAGA is glycosylated instead of the two subunits for lysosomal human AGA (hAGA, and these glycosylations are partially resistant to PGNase F treatment. The two venom AGAs are secreted as fully activated enzymes, they have a similar aspartylglucosaminidase activity and are both also efficient asparaginases. Once AGAs are injected into the larvae of the Drosophila melanogaster host, the asparaginase activity may play a role in modulating their physiology. Altogether, our data provide new elements for a better understanding of the secretion and the role of venom AGAs as virulence factors in the parasitoid wasps' success.

Menadione serves as a substrate for P-glycoprotein: implication in chemosensitizing activity.

Science.gov (United States)

Oh, Seok-Jeong; Han, Hyo-Kyung; Kang, Keon-Wook; Lee, Young-Joo; Lee, Moo-Yeol

2013-04-01

Based on its chemosensitizing effect, we questioned whether menadione is an inhibitor or a substrate of P-glycoprotein (P-gp). To test this hypothesis, we assessed the effect of menadione on P-gp activity and examined the P-gp-dependency of cellular accumulation and cytotoxicity of menadione as well. Treatment with menadione resulted in the concentration-dependent increase of rhodamine 123 (Rh123) accumulation in P-gp-overexpressing MDCKII/MDR1 and NCI/ADR-RES cells, suggesting that menadione inhibits Rh123 extrusion by P-gp. Compared with MDCKII or MCF-7, intracellular distribution of [(3)H]-menadione was significantly lower in MDCKII/MDR1 or NCI/ADR-RES cells, which could be restored by the P-gp inhibitors, verapamil and quinidine. Consistent with these results, MDCKII/MDR1 or NCI/ADR-RES cells were more resistant to the cytotoxicity of menadione than MDCKII or MCF-7 cells, respectively. Such resistance was abolished by the combined treatment of verapamil and quinidine in NCI/ADR-RES cells. Our study identified menadione as a substrate of P-gp, which presumably, acts as the mechanism for the chemosensitizing effect. Menadione may be a promising chemotherapeutic enhancer by its ability of circumventing drug resistance, in addition to its own anti-cancer activity.

Glycoproteins and sialyl transferase of human B lymphoblastoid cell lines

International Nuclear Information System (INIS)

Lui, S.W.L.; Ng, M.H.

1980-01-01

We used two radiolabeling methods to study glycoproteins on the surface of lymphoblastoid cells. One of the methods affects tritiation of residues which are oxidized with galactose oxidase and the other causes tritiation of neuraminic acid residues. This approach was shown to allow a better resolution of cell surface glycoproteins than if either method were used alone. Glycoproteins of B 1 - 19 cells which harbor the Epstein-Barr virus genomes were compared with those of its parental cell line, BJAB, which does not harbor the viral genomes. These studies did not reveal a unique viral protein. A 28,000 mol. wt. glycoprotein was found to be the most prominent neuraminic acidlabeled product of B 1 - 19 cells and also of the two other cell lines, Raji and Ly38, which harbor the EBV genomes. A similar molecular weight species from BJAB cells identified by galactose oxidase labeling might be deficient in neuraminic acid residues as it was poorly labeled by the periodate oxidation method. The neuraminic acid content and level of sialyl transferase of BJAB cells were found to be lower than those of the other cell lines studied. (auth.)

Identification, isolation, and N-terminal sequencing of style glycoproteins associated with self-incompatibility in Nicotiana alata.

Science.gov (United States)

Jahnen, W; Batterham, M P; Clarke, A E; Moritz, R L; Simpson, R J

1989-05-01

S-Gene-associated glycoproteins (S-glycoproteins) from styles of Nicotiana alata, identified by non-equilibrium two-dimensional electrophoresis, were purified by cation exchange fast protein liquid chromatography with yields of 0.5 to 8 micrograms of protein per style, depending on the S-genotype of the plant. The method relies on the highly basic nature of the S-glycoproteins. The elution profiles of the different S-glycoproteins from the fast protein liquid chromatography column were characteristic of each S-glycoprotein, and could be used to establish the S-genotype of plants in outbreeding populations. In all cases, the S-genotype predicted from the style protein profile corresponded to that predicted from DNA gel blot analysis using S-allele-specific DNA probes and to that established by conventional breeding tests. Amino-terminal sequences of five purified S-glycoproteins showed a high degree of homology with the previously published sequences of N. alata and Lycopersicon esculentum S-glycoproteins.

Plasmalogen enrichment in exosomes secreted by a nematode parasite versus those derived from its mouse host: implications for exosome stability and biology

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Fabio Simbari

2016-07-01

Full Text Available Extracellular vesicles (EVs mediate communication between cells and organisms across all 3 kingdoms of life. Several reports have demonstrated that EVs can transfer molecules between phylogenetically diverse species and can be used by parasites to alter the properties of the host environment. Whilst the concept of vesicle secretion and uptake is broad reaching, the molecular composition of these complexes is expected to be diverse based on the physiology and environmental niche of different organisms. Exosomes are one class of EVs originally defined based on their endocytic origin, as these derive from multivesicular bodies that then fuse with the plasma membrane releasing them into the extracellular environment. The term exosome has also been used to describe any small EVs recovered by high-speed ultracentrifugation, irrespective of origin since this is not always well characterized. Here, we use comparative global lipidomic analysis to examine the composition of EVs, which we term exosomes, that are secreted by the gastrointestinal nematode, Heligmosomoides polygyrus, in relation to exosomes secreted by cells of its murine host. Ultra-performance liquid chromatography – tandem mass spectrometry (UPLC-MS/MS analysis reveals a 9- to 62-fold enrichment of plasmalogens, as well as other classes of ether glycerophospholipids, along with a relative lack of cholesterol and sphingomyelin (SM in the nematode exosomes compared with those secreted by murine cells. Biophysical analyses of the membrane dynamics of these exosomes demonstrate increased rigidity in those from the nematode, and parallel studies with synthetic vesicles support a role of plasmalogens in stabilizing the membrane structure. These results suggest that nematodes can maintain exosome membrane structure and integrity through increased plasmalogens, compensating for diminished levels of other lipids, including cholesterol and SM. This work also illuminates the prevalence of

The H2 receptor antagonist nizatidine is a P-glycoprotein substrate: characterization of its intestinal epithelial cell efflux transport.

Science.gov (United States)

Dahan, Arik; Sabit, Hairat; Amidon, Gordon L

2009-06-01

The aim of this study was to elucidate the intestinal epithelial cell efflux transport processes that are involved in the intestinal transport of the H(2) receptor antagonist nizatidine. The intestinal epithelial efflux transport mechanisms of nizatidine were investigated and characterized across Caco-2 cell monolayers, in the concentration range 0.05-10 mM in both apical-basolateral (AP-BL) and BL-AP directions, and the transport constants of P-glycoprotein (P-gp) efflux activity were calculated. The concentration-dependent effects of various P-gp (verapamil, quinidine, erythromycin, ketoconazole, and cyclosporine A), multidrug resistant-associated protein 2 (MRP2; MK-571, probenecid, indomethacin, and p-aminohipuric acid), and breast cancer resistance protein (BCRP; Fumitremorgin C) inhibitors on nizatidine bidirectional transport were examined. Nizatidine exhibited 7.7-fold higher BL-AP than AP-BL Caco-2 permeability, indicative of net mucosal secretion. All P-gp inhibitors investigated displayed concentration-dependent inhibition on nizatidine secretion in both directions. The IC(50) of verapamil on nizatidine P-gp secretion was 1.2 x 10(-2) mM. In the absence of inhibitors, nizatidine displayed concentration-dependent secretion, with one saturable (J(max) = 5.7 x 10(-3) nmol cm(-2) s(-1) and K(m) = 2.2 mM) and one nonsaturable component (K(d) = 7 x 10(-4) microL cm(-2) s(-1)). Under complete P-gp inhibition, nizatidine exhibited linear secretory flux, with a slope similar to the nonsaturable component. V(max) and K(m) estimated for nizatidine P-gp-mediated secretion were 4 x 10(-3) nmol cm(-2) s(-1) and 1.2 mM, respectively. No effect was obtained with the MRP2 or the BCRP inhibitors. Being a drug commonly used in pediatrics, adults, and elderly, nizatidine susceptibility to efflux transport by P-gp revealed in this paper may be of significance in its absorption, distribution, and clearance, as well as possible drug-drug interactions.

The peanut lectin-binding glycoproteins of human epidermal keratinocytes

International Nuclear Information System (INIS)

Morrison, A.I.; Keeble, S.; Watt, F.M.

1988-01-01

The peanut lectin (PNA) is known to bind more strongly to keratinocytes that are undergoing terminal differentiation than to proliferating keratinocytes. In order to investigate the significance of this change in cell-surface carbohydrate authors have identified the PNA-binding glycoproteins of cultured human keratinocytes and antibodies against them. Two heavily glycosylated bands of 110 and 250 kDa were resolved by PAGE of [ 14 C]galactose- or [ 14 C]mannose- and [ 14 C]glucosamine-labeled cell extracts eluted with galactose from PNA affinity columns. The higher molecular weight band was also detected on PNA blots of unlabeled cell extracts transferred to nitrocellulose. Both bands were sensitive to pronase digestion, but only the 250-kDa band was digested with trypsin. A rabbit antiserum that we prepared (anti-PNA-gp) immunoprecipitated both bands from cell extracts. In contrast to PNA, anti-PNA-gp bound equally to proliferating and terminally differentiating cells, indicating that some epitope(s) of the PNA-binding glycoproteins is present on the cell surface prior to terminal differentiation. When keratinocytes grown as a monolayer in low-calcium medium were switched to medium containing 2 mM calcium ions in order to induce desmosome formation and stratification, there was a dramatic redistribution of the PNA-binding glycoproteins, which became concentrated at the boundaries between cells. This may suggest a role for the glycoproteins in cell-cell interactions during stratification

A Novel Method for Detection of Glycoproteins on Sodium Dodecyl Sulphate Polyacrylamide Gel Using Radio-Iodinated Tyrosine

DEFF Research Database (Denmark)

Nalla, Amarnadh; Draz, Hossam M.; Dole, Anita

2009-01-01

The aim of this study is to develop a novel method for detection of glycoproteins on polyacrylamide gel. In this method, radio-iodinated-tyrosine (125I-tyrosine) was conjugated to glycoprotein by schiff's base mechanism on the sodium dodecyl sulfate- polyacrylamide gel. Ovalbumin and Concanavalin...... of glycoproteins using 125I-tyrosine selectively detected ovalbumin. Present results showed that MPD enhanced glycoprotein detection method can be used as a sensitive tool for the detection of glycoproteins on polyacrylamide gel...

Genetic Diversity Underlying the Envelope Glycoproteins of Hepatitis C Virus: Structural and Functional Consequences and the Implications for Vaccine Design

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Alexander W. Tarr

2015-07-01

Full Text Available In the 26 years since the discovery of Hepatitis C virus (HCV a major global research effort has illuminated many aspects of the viral life cycle, facilitating the development of targeted antivirals. Recently, effective direct-acting antiviral (DAA regimens with >90% cure rates have become available for treatment of chronic HCV infection in developed nations, representing a significant advance towards global eradication. However, the high cost of these treatments results in highly restricted access in developing nations, where the disease burden is greatest. Additionally, the largely asymptomatic nature of infection facilitates continued transmission in at risk groups and resource constrained settings due to limited surveillance. Consequently a prophylactic vaccine is much needed. The HCV envelope glycoproteins E1 and E2 are located on the surface of viral lipid envelope, facilitate viral entry and are the targets for host immunity, in addition to other functions. Unfortunately, the extreme global genetic and antigenic diversity exhibited by the HCV glycoproteins represents a significant obstacle to vaccine development. Here we review current knowledge of HCV envelope protein structure, integrating knowledge of genetic, antigenic and functional diversity to inform rational immunogen design.

P-glycoprotein targeted nanoscale drug carriers

KAUST Repository

Li, Wengang; Abu Samra, Dina Bashir Kamil; Merzaban, Jasmeen; Khashab, Niveen M.

2013-01-01

Multi-drug resistance (MDR) is a trend whereby tumor cells exposed to one cytotoxic agent develop cross-resistance to a range of structurally and functionally unrelated compounds. P -glycoprotein (P -gp) efflux pump is one of the mostly studied drug

The short mRNA isoform of the immunoglobulin superfamily, member 1 gene encodes an intracellular glycoprotein.

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Ying Wang

Full Text Available Mutations in the immunoglobulin superfamily, member 1 gene (IGSF1/Igsf1 cause an X-linked form of central hypothyroidism. The canonical form of IGSF1 is a transmembrane glycoprotein with 12 immunoglobulin (Ig loops. The protein is co-translationally cleaved into two sub-domains. The carboxyl-terminal domain (CTD, which contains the last 7 Ig loops, is trafficked to the plasma membrane. Most pathogenic mutations in IGSF1 map to the portion of the gene encoding the CTD. IGSF1/Igsf1 encodes a variety of transcripts. A little studied, but abundant splice variant encodes a truncated form of the protein, predicted to contain the first 2 Ig loops of the full-length IGSF1. The protein (hereafter referred to as IGSF1 isoform 2 or IGSF1-2 is likely retained in most individuals with IGSF1 mutations. Here, we characterized basic biochemical properties of the protein as a foray into understanding its potential function. IGSF1-2, like the IGSF1-CTD, is a glycoprotein. In both mouse and rat, the protein is N-glycosylated at a single asparagine residue in the first Ig loop. Contrary to earlier predictions, neither the murine nor rat IGSF1-2 is secreted from heterologous or homologous cells. In addition, neither protein associates with the plasma membrane. Rather, IGSF1-2 appears to be retained in the endoplasmic reticulum. Whether the protein plays intracellular functions or is trafficked through the secretory pathway under certain physiologic or pathophysiologic conditions has yet to be determined.

Multiple genes encode the major surface glycoprotein of Pneumocystis carinii

DEFF Research Database (Denmark)

Kovacs, J A; Powell, F; Edman, J C

1993-01-01

hydrophobic region at the carboxyl terminus. The presence of multiple related msg genes encoding the major surface glycoprotein of P. carinii suggests that antigenic variation is a possible mechanism for evading host defenses. Further characterization of this family of genes should allow the development......The major surface antigen of Pneumocystis carinii, a life-threatening opportunistic pathogen in human immunodeficiency virus-infected patients, is an abundant glycoprotein that functions in host-organism interactions. A monoclonal antibody to this antigen is protective in animals, and thus...... blot studies using chromosomal or restricted DNA, the major surface glycoproteins are the products of a multicopy family of genes. The predicted protein has an M(r) of approximately 123,000, is relatively rich in cysteine residues (5.5%) that are very strongly conserved, and contains a well conserved...

Restoration of glycoprotein Erns dimerization via pseudoreversion partially restores virulence of classical swine fever virus.

Science.gov (United States)

Tucakov, Anna Katharina; Yavuz, Sabine; Schürmann, Eva-Maria; Mischler, Manjula; Klingebeil, Anne; Meyers, Gregor

2018-01-01

The classical swine fever virus (CSFV) represents one of the most important pathogens of swine. The CSFV glycoprotein E rns is an essential structural protein and an important virulence factor. The latter is dependent on the RNase activity of this envelope protein and, most likely, its secretion from the infected cell. A further important feature with regard to its function as a virulence factor is the formation of disulfide-linked E rns homodimers that are found in virus-infected cells and virions. Mutant CSFV lacking cysteine (Cys) 171, the residue responsible for intermolecular disulfide bond formation, were found to be attenuated in pigs (Tews BA, Schürmann EM, Meyers G. J Virol 2009;83:4823-4834). In the course of an animal experiment with such a dimerization-negative CSFV mutant, viruses were reisolated from pigs that contained a mutation of serine (Ser) 209 to Cys. This mutation restored the ability to form disulphide-linked E rns homodimers. In transient expression studies E rns mutants carrying the S209C change were found to form homodimers with about wt efficiency. Also the secretion level of the mutated proteins was equivalent to that of wt E rns . Virus mutants containing the Cys171Ser/Ser209Cys configuration exhibited wt growth rates and increased virulence when compared with the Cys171Ser mutant. These results provide further support for the connection between CSFV virulence and E rns dimerization.

Identification of B- and T-cell epitopes from glycoprotein B of herpes simplex virus 2 and evaluation of their immunogenicity and protection efficacy.

Science.gov (United States)

Liu, Kun; Jiang, Deyu; Zhang, Liangyan; Yao, Zhidong; Chen, Zhongwei; Yu, Sanke; Wang, Xiliang

2012-04-19

Herpes simplex virus (HSV) infection is a major health concern worldwide. Evidence obtained from animals and humans indicates that B- and T-cell responses contribute to protective immunity against herpes virus infection. Glycoprotein B is a transmembrane envelope component of HSV-1 and HSV-2, which plays an important role in virion morphogenesis and penetration into host cells, and can induce neutralizing antibodies and protective T-cell response when it is used to immunize humans and animals. However, little is known about gB epitopes that are involved in B- and T-cell activities in vitro and in vivo. Thus, the HSV-2 gB sequence was screened using B- and T-cell epitope prediction systems, and the B-cell regions and the HLA-A*0201-restricted epitopes were identified. These B-cell epitopes elicited high IgG antibody titers in Balb/C mice, with a predominantly IgG1 subclass distribution, which indicated a Th2 bias. Specific IgGs induced by these two epitopes were evaluated as the neutralizing antibodies for virus neutralization. The predicted T-cell epitopes stabilized the HLA-A*0201 molecules on T(2) cells, and stimulate interferon-γ-secreting and cytotoxic CD8(+) T cells. Immunization with the predicted peptides reduced virus shedding and protected against lethal viral challenge in mice. The functional epitopes described herein, both B- and T-cell epitopes, are potentially implicated in vaccine development. Copyright © 2012. Published by Elsevier Ltd.

The O-Linked Glycome and Blood Group Antigens ABO on Mucin-Type Glycoproteins in Mucinous and Serous Epithelial Ovarian Tumors.

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Varvara Vitiazeva

Full Text Available Mucins are heavily O-glycosylated proteins where the glycosylation has been shown to play an important role in cancer. Normal epithelial ovarian cells do not express secreted mucins, but their abnormal expression has previously been described in epithelial ovarian cancer and may relate to tumor formation and progression. The cyst fluids were shown to be a rich source for acidic glycoproteins. The study of these proteins can potentially lead to the identification of more effective biomarkers for ovarian cancer.In this study, we analyzed the expression of the MUC5AC and the O-glycosylation of acidic glycoproteins secreted into ovarian cyst fluids. The samples were obtained from patients with serous and mucinous ovarian tumors of different stages (benign, borderline, malignant and grades. The O-linked oligosaccharides were released and analyzed by negative-ion graphitized carbon Liquid Chromatography (LC coupled to Electrospray Ionization tandem Mass Spectrometry (ESI-MSn. The LC-ESI-MSn of the oligosaccharides from ovarian cyst fluids displayed differences in expression of fucose containing structures such as blood group ABO antigens and Lewis-type epitopes.The obtained data showed that serous and mucinous benign adenomas, mucinous low malignant potential carcinomas (LMPs, borderline and mucinous low-grade carcinomas have a high level of blood groups and Lewis type epitopes. In contrast, this type of fucosylated structures were low abundant in the high-grade mucinous carcinomas or in serous carcinomas. In addition, the ovarian tumors that showed a high level of expression of blood group antigens also revealed a strong reactivity towards the MUC5AC antibody. To visualize the differences between serous and mucinous ovarian tumors based on the O-glycosylation, a hierarchical cluster analysis was performed using mass spectrometry average compositions (MSAC.Mucinous benign and LMPs along with mucinous low-grade carcinomas appear to be different from

Glycoproteins of axonal transport: affinity chromatography on fucose-specific lectins

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Gustavsson, S.; Ohlson, C.; Karlsson, J.O.

1982-03-01

Rapidly transported fucose-labeled glycoproteins from axons of rabbit retinal ganglion cells were solubilized with nonionic detergents. The solubilized components were subjected to affinity chromatography on three different fucose-specific lectins. A recently characterized fucose-specific lectin from Aleuria aurantia bound reversibly approximately 60% of the applied protein-bound radioactivity. The lectins from Lotus tetragonolobus and Ulex europaeus bound are very small proportions of the labeled rapidly transported glycoproteins.

On Converting Secret Sharing Scheme to Visual Secret Sharing Scheme

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Wang Daoshun

2010-01-01

Full Text Available Abstract Traditional Secret Sharing (SS schemes reconstruct secret exactly the same as the original one but involve complex computation. Visual Secret Sharing (VSS schemes decode the secret without computation, but each share is m times as big as the original and the quality of the reconstructed secret image is reduced. Probabilistic visual secret sharing (Prob.VSS schemes for a binary image use only one subpixel to share the secret image; however the probability of white pixels in a white area is higher than that in a black area in the reconstructed secret image. SS schemes, VSS schemes, and Prob. VSS schemes have various construction methods and advantages. This paper first presents an approach to convert (transform a -SS scheme to a -VSS scheme for greyscale images. The generation of the shadow images (shares is based on Boolean XOR operation. The secret image can be reconstructed directly by performing Boolean OR operation, as in most conventional VSS schemes. Its pixel expansion is significantly smaller than that of VSS schemes. The quality of the reconstructed images, measured by average contrast, is the same as VSS schemes. Then a novel matrix-concatenation approach is used to extend the greyscale -SS scheme to a more general case of greyscale -VSS scheme.

Secreted Clusterin protein inhibits osteoblast differentiation of bone marrow mesenchymal stem cells by suppressing ERK1/2 signaling pathway.

Science.gov (United States)

Abdallah, Basem M; Alzahrani, Abdullah M; Kassem, Moustapha

2018-05-01

Secreted Clusterin (sCLU, also known as Apolipoprotein J) is an anti-apoptotic glycoprotein involved in the regulation of cell proliferation, lipid transport, extracellular tissue remodeling and apoptosis. sCLU is expressed and secreted by mouse bone marrow-derived skeletal (stromal or mesenchymal) stem cells (mBMSCs), but its functional role in MSC biology is not known. In this study, we demonstrated that Clusterin mRNA expression and protein secretion in conditioned medium increased during adipocyte differentiation and decreased during osteoblast differentiation of mBMSCs. Treatment of mBMSC cultures with recombinant sCLU protein increased cell proliferation and exerted an inhibitory effect on the osteoblast differentiation while stimulated adipocyte differentiation in a dose-dependent manner. siRNA-mediated silencing of Clu expression in mBMSCs reduced adipocyte differentiation and stimulated osteoblast differentiation of mBMSCs. Furthermore, the inhibitory effect of sCLU on the osteoblast differentiation of mBMSCs was mediated by the suppression of extracellular signal-regulated kinase (ERK1/2) phosphorylation. In conclusion, we identified sCLU as a regulator of mBMSCs lineage commitment to osteoblasts versus adipocytes through a mechanism mediated by ERK1/2 signaling. Inhibiting sCLU is a possible therapeutic approach for enhancing osteoblast differentiation and consequently bone formation. Copyright © 2018 Elsevier Inc. All rights reserved.

Development of a radioimmunoassay for 'Tamm-Horsfall-like' glycoprotein in serum and cerebrospinal fluid

International Nuclear Information System (INIS)

Hartmann, L.; Bringuier, A.-F.; Schuller, E.

1983-01-01

Affinity chromatography purification was combined with a radioimmunoassay for 'Tamm-Horsfall-like' glycoprotein. This enabled serum comcentrations to be established and to demonstrate its presence in cerebrospinal fluid for the first time. This assay method used in different circumstances suggests a multifocal synthesis. Nevertheless, urinary Tamm-Horsfall glycoprotein so far must be distinguished from the serum or cerebrospinal fluid Tamm-Horsfall-like glycoprotein. (Auth.)

Authentication Without Secrets

Energy Technology Data Exchange (ETDEWEB)

Pierson, Lyndon G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Robertson, Perry J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-11-01

This work examines a new approach to authentication, which is the most fundamental security primitive that underpins all cyber security protections. Current Internet authentication techniques require the protection of one or more secret keys along with the integrity protection of the algorithms/computations designed to prove possession of the secret without actually revealing it. Protecting a secret requires physical barriers or encryption with yet another secret key. The reason to strive for "Authentication without Secret Keys" is that protecting secrets (even small ones only kept in a small corner of a component or device) is much harder than protecting the integrity of information that is not secret. Promising methods are examined for authentication of components, data, programs, network transactions, and/or individuals. The successful development of authentication without secret keys will enable far more tractable system security engineering for high exposure, high consequence systems by eliminating the need for brittle protection mechanisms to protect secret keys (such as are now protected in smart cards, etc.). This paper is a re-release of SAND2009-7032 with new figures numerous edits.

Glycoproteins functionalized natural and synthetic polymers for prospective biomedical applications: A review.

Science.gov (United States)

Tabasum, Shazia; Noreen, Aqdas; Kanwal, Arooj; Zuber, Mohammad; Anjum, Muhammad Naveed; Zia, Khalid Mahmood

2017-05-01

Glycoproteins have multidimensional properties such as biodegradability, biocompatibility, non-toxicity, antimicrobial and adsorption properties; therefore, they have wide range of applications. They are blended with different polymers such as chitosan, carboxymethyl cellulose (CMC), polyvinyl pyrrolidone (PVP), polycaprolactone (PCL), heparin, polystyrene fluorescent nanoparticles (PS-NPs) and carboxyl pullulan (PC) to improve their properties like thermal stability, mechanical properties, resistance to pH, chemical stability and toughness. Considering the versatile charateristics of glycoprotein based polymers, this review sheds light on synthesis and characterization of blends and composites of glycoproteins, with natural and synthetic polymers and their potential applications in biomedical field such as drug delivery system, insulin delivery, antimicrobial wound dressing uses, targeting of cancer cells, development of anticancer vaccines, development of new biopolymers, glycoproteome research, food product and detection of dengue glycoproteins. All the technical scientific issues have been addressed; highlighting the recent advancement. Copyright © 2017 Elsevier B.V. All rights reserved.

Preparation of 131I-asialo-α1-acid glycoprotein

International Nuclear Information System (INIS)

Rijk, P.P. van

1975-01-01

α 1 -Acid glycoprotein (orosomucoid) was prepared from a byproduct of the ethanol plasma fractionation by means of ion-exchange procedures. Immunoelectrophoresis suggested a high degree of purity; the purified protein contained 13.5% sialic acid and 17.8% hexose. The α 1 -acid glycoprotein was modified by removal of sialic acid with neurominidase (E.C. 3.2.1.18) followed by iodination with 131 I. The purpose of the preparation, its potential use as a pharmacon for liver-function studies in nuclear medicine, is the subject of further study

Nipah virus infection and glycoprotein targeting in endothelial cells

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Maisner Andrea

2010-11-01

Full Text Available Abstract Background The highly pathogenic Nipah virus (NiV causes fatal respiratory and brain infections in animals and humans. The major hallmark of the infection is a systemic endothelial infection, predominantly in the CNS. Infection of brain endothelial cells allows the virus to overcome the blood-brain-barrier (BBB and to subsequently infect the brain parenchyma. However, the mechanisms of NiV replication in endothelial cells are poorly elucidated. We have shown recently that the bipolar or basolateral expression of the NiV surface glycoproteins F and G in polarized epithelial cell layers is involved in lateral virus spread via cell-to-cell fusion and that correct sorting depends on tyrosine-dependent targeting signals in the cytoplasmic tails of the glycoproteins. Since endothelial cells share many characteristics with epithelial cells in terms of polarization and protein sorting, we wanted to elucidate the role of the NiV glycoprotein targeting signals in endothelial cells. Results As observed in vivo, NiV infection of endothelial cells induced syncytia formation. The further finding that infection increased the transendothelial permeability supports the idea of spread of infection via cell-to-cell fusion and endothelial cell damage as a mechanism to overcome the BBB. We then revealed that both glycoproteins are expressed at lateral cell junctions (bipolar, not only in NiV-infected primary endothelial cells but also upon stable expression in immortalized endothelial cells. Interestingly, mutation of tyrosines 525 and 542/543 in the cytoplasmic tail of the F protein led to an apical redistribution of the protein in endothelial cells whereas tyrosine mutations in the G protein had no effect at all. This fully contrasts the previous results in epithelial cells where tyrosine 525 in the F, and tyrosines 28/29 in the G protein were required for correct targeting. Conclusion We conclude that the NiV glycoprotein distribution is responsible for

Isolation of glycoproteins from brown algae

DEFF Research Database (Denmark)

2015-01-01

The present invention relates to a novel process for the isolation of unique anti-oxidative glycoproteins from the pH precipitated fractions of enzymatic extracts of brown algae. Two brown seaweeds viz, Fucus serratus and Fucus vesiculosus were hydrolysed by using 3 enzymes viz, Alcalase, Viscozyme...

Molecular cloning and expression of cDNA encoding a lumenal calcium binding glycoprotein from sarcoplasmic reticulum

International Nuclear Information System (INIS)

Leberer, E.; Charuk, J.H.M.; MacLennan, D.H.; Green, N.M.

1989-01-01

Antibody screening was used to isolate a cDNA encoding the 160-kDa glycoprotein of rabbit skeletal muscle sarcoplasmic reticulum. The cDNA is identical to that encoding the 53-kDa glycoprotein except that it contains an in-frame insertion of 1,308 nucleotides near its 5' end, apparently resulting from alternative splicing. The protein encoded by the cDNA would contain a 19-residue NH 2 -terminal signal sequence and a 453-residue COOH-terminal sequence identical to the 53-kDa glycoprotein. It would also contain a 436-amino acid insert between these sequences. This insert would be highly acidic, suggesting that it might bind Ca 2+ . The purified 160-kDa glycoprotein and the glycoprotein expressed in COS-1 cells transfected with cDNA encoding the 160-kDa glycoprotein were shown to bind 45 C 2+ in a gel overlay assay. The protein was shown to be located in the lumen of the sarcoplasmic reticulum and to be associated through Ca 2+ with the membrane. The authors propose that this lumenal Ca 2+ binding glycoprotein of the sarcoplasmic reticulum be designated sarcalumenin

Australine, a pyrrolizidine alkaloid that inhibits amyloglucosidase and glycoprotein processing

International Nuclear Information System (INIS)

Tropea, J.E.; Molyneux, R.J.; Kaushal, G.P.; Pan, Y.T.; Mitchell, M.; Elbein, A.D.

1989-01-01

Australine is a polyhydroxylated pyrrolizidine alkaloid that was isolated from the seeds of the Australian tree Castanospermum australe and characterized by NMR and X-ray diffraction analysis. Since swainsonine and catanospermine are polyhydroxylated indolizidine alkaloids that inhibit specific glycosidases, the authors tested australine against a variety of exoglycosidases to determine whether it would inhibit any of these enzymes. This alkaloid proved to be a good inhibitor of the α-glucosidase amyloglucosidase (50% inhibition at 5.8 μM), but it did not inhibit β-glucosidase, α- or β-mannosidase, or α- or β-galactosidase. The inhibition of amyloglucosidase was of a competitive nature. Australine also inhibited the glycoprotein processing enzyme glucosidase I, but had only slight activity toward glucosidase II. When incubated with cultured cells, this alkaloid inhibited glycoprotein processing at the glucosidase I step and caused the accumulation of glycoproteins with Glc 3 Man 7-9 (GlcNAc) 2 -oligosaccharides

Statins Suppress Ebola Virus Infectivity by Interfering with Glycoprotein Processing.

Science.gov (United States)

Shrivastava-Ranjan, Punya; Flint, Mike; Bergeron, Éric; McElroy, Anita K; Chatterjee, Payel; Albariño, César G; Nichol, Stuart T; Spiropoulou, Christina F

2018-05-01

Ebola virus (EBOV) infection is a major public health concern due to high fatality rates and limited effective treatments. Statins, widely used cholesterol-lowering drugs, have pleiotropic mechanisms of action and were suggested as potential adjunct therapy for Ebola virus disease (EVD) during the 2013-2016 outbreak in West Africa. Here, we evaluated the antiviral effects of statin (lovastatin) on EBOV infection in vitro Statin treatment decreased infectious EBOV production in primary human monocyte-derived macrophages and in the hepatic cell line Huh7. Statin treatment did not interfere with viral entry, but the viral particles released from treated cells showed reduced infectivity due to inhibition of viral glycoprotein processing, as evidenced by decreased ratios of the mature glycoprotein form to precursor form. Statin-induced inhibition of infectious virus production and glycoprotein processing was reversed by exogenous mevalonate, the rate-limiting product of the cholesterol biosynthesis pathway, but not by low-density lipoprotein. Finally, statin-treated cells produced EBOV particles devoid of the surface glycoproteins required for virus infectivity. Our findings demonstrate that statin treatment inhibits EBOV infection and suggest that the efficacy of statin treatment should be evaluated in appropriate animal models of EVD. IMPORTANCE Treatments targeting Ebola virus disease (EVD) are experimental, expensive, and scarce. Statins are inexpensive generic drugs that have been used for many years for the treatment of hypercholesterolemia and have a favorable safety profile. Here, we show the antiviral effects of statins on infectious Ebola virus (EBOV) production. Our study reveals a novel molecular mechanism in which statin regulates EBOV particle infectivity by preventing glycoprotein processing and incorporation into virus particles. Additionally, statins have anti-inflammatory and immunomodulatory effects. Since inflammation and dysregulation of the immune

The expression and serological reactivity of recombinant canine herpesvirus 1 glycoprotein D

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MarkéŽta Vaňkov‡á

2016-01-01

Full Text Available The aim of this work was to express recombinant glycoprotein D of canine herpesvirus 1 in bacterial cells and to evaluate its diagnostic sensitivity and specificity when compared to traditional serological methods. The gene fragment coding glycoprotein D of canine herpesvirus 1 was amplified by polymerase chain reaction, cloned into plasmid vector and expressed in Escherichia coli cells. Recombinant protein was then purified and used as an antigen in immunoblot for a detection of canine herpesvirus 1 specific antibodies. Antibody testing was performed on the panel of 100 canine sera by immunoblot with recombinant glycoprotein D as antigen and compared with indirect immunofluorescence assay. Serum samples were collected from 83 dogs with no history of canine herpesvirus 1 or reproductive disorders, and from 17 dogs from breeding kennels with a history of canine herpesvirus 1 related reproductive disorders. Sensitivity of glycoprotein D based immunoblot was 89.2% and specificity was 93%. Kappa value was calculated to be 0.8 between immunoblot and indirect immunofluorescence assay. Antibodies against canine herpesvirus 1 infection were detected in 33% of samples by immunoblot assay. Our study confirms that recombinant glycoprotein D expressed in bacterial cells could be used as a suitable and sensitive antigen for immunological tests and that herpesvirus infection seems to be common among the canine population in the Czech Republic.

Trading secrets: Jews and the early modern quest for clandestine knowledge.

Science.gov (United States)

Jütte, Daniel

2012-12-01

This essay explores the significance and function of secrecy and secret sciences in Jewish-Christian relations and in Jewish culture in the early modern period. It shows how the trade in clandestine knowledge and the practice of secret sciences became a complex, sometimes hazardous space for contact between Jews and Christians. By examining this trade, the essay clarifies the role of secrecy in the early modern marketplace of knowledge. The attribution of secretiveness to Jews was a widespread topos in early modern European thought. However, relatively little is known about the implications of such beliefs in science or in daily life. The essay pays special attention to the fact that trade in secret knowledge frequently offered Jews a path to the center of power, especially at court. Furthermore, it becomes clear that the practice of secret sciences, the trade in clandestine knowledge, and a mercantile agenda were often inextricably interwoven. Special attention is paid to the Italian-Jewish alchemist, engineer, and entrepreneur Abramo Colorni (ca. 1544-1599), whose career illustrates the opportunities provided by the marketplace of secrets at that time. Much scholarly (and less scholarly) attention has been devoted to whether and what Jews "contributed" to what is commonly called the "Scientific Revolution." This essay argues that the question is misdirected and that, instead, we should pay more attention to the distinctive opportunities offered by the early modern economy of secrecy.

Global site-specific analysis of glycoprotein N-glycan processing.

Science.gov (United States)

Cao, Liwei; Diedrich, Jolene K; Ma, Yuanhui; Wang, Nianshuang; Pauthner, Matthias; Park, Sung-Kyu Robin; Delahunty, Claire M; McLellan, Jason S; Burton, Dennis R; Yates, John R; Paulson, James C

2018-06-01

N-glycans contribute to the folding, stability and functions of the proteins they decorate. They are produced by transfer of the glycan precursor to the sequon Asn-X-Thr/Ser, followed by enzymatic trimming to a high-mannose-type core and sequential addition of monosaccharides to generate complex-type and hybrid glycans. This process, mediated by the concerted action of multiple enzymes, produces a mixture of related glycoforms at each glycosite, making analysis of glycosylation difficult. To address this analytical challenge, we developed a robust semiquantitative mass spectrometry (MS)-based method that determines the degree of glycan occupancy at each glycosite and the proportion of N-glycans processed from high-mannose type to complex type. It is applicable to virtually any glycoprotein, and a complete analysis can be conducted with 30 μg of protein. Here, we provide a detailed description of the method that includes procedures for (i) proteolytic digestion of glycoprotein(s) with specific and nonspecific proteases; (ii) denaturation of proteases by heating; (iii) sequential treatment of the glycopeptide mixture with two endoglycosidases, Endo H and PNGase F, to create unique mass signatures for the three glycosylation states; (iv) LC-MS/MS analysis; and (v) data analysis for identification and quantitation of peptides for the three glycosylation states. Full coverage of site-specific glycosylation of glycoproteins is achieved, with up to thousands of high-confidence spectra hits for each glycosite. The protocol can be performed by an experienced technician or student/postdoc with basic skills for proteomics experiments and takes ∼7 d to complete.

Dynamics of synthetic activity of RNA and glycoproteins in epithel cells of endometrium in heifers after ovulation

International Nuclear Information System (INIS)

Pivko, J.; Grafenau, P.; Uhrin, V.; Kopecny, V.

1998-01-01

represented in the supranuclear parts. Intensive synthesis takes place in cells of glands of the functional zone on 3rd day, the intensity of the reaction is lower in the basal zone. The creation of glycoproteins is identical in surface as well as in deep parts of glands on 6th day, it declines in the surface parts on 9th day, whereas it remains on the same level in other parts. The intensive RNA synthesis was sustained in nuclei of epithel cells of uterus in luminal and glandular epithel. The synthetic and secretion activities of glycoproteins are intensive in the luteal phase, they decrease slightly in surface cells of glands white they are preserved in the deep cells

Analytical Pipeline for Discovery and Verification of Glycoproteins from Plasma-Derived Extracellular Vesicles as Breast Cancer Biomarkers.

Science.gov (United States)

Chen, I-Hsuan; Aguilar, Hillary Andaluz; Paez Paez, J Sebastian; Wu, Xiaofeng; Pan, Li; Wendt, Michael K; Iliuk, Anton B; Zhang, Ying; Tao, W Andy

2018-05-15

Glycoproteins comprise more than half of current FDA-approved protein cancer markers, but the development of new glycoproteins as disease biomarkers has been stagnant. Here we present a pipeline to develop glycoproteins from extracellular vesicles (EVs) through integrating quantitative glycoproteomics with a novel reverse phase glycoprotein array and then apply it to identify novel biomarkers for breast cancer. EV glycoproteomics show promise in circumventing the problems plaguing current serum/plasma glycoproteomics and allowed us to identify hundreds of glycoproteins that have not been identified in blood. We identified 1,453 unique glycopeptides representing 556 glycoproteins in EVs, among which 20 were verified significantly higher in individual breast cancer patients. We further applied a novel glyco-specific reverse phase protein array to quantify a subset of the candidates. Together, this study demonstrates the great potential of this integrated pipeline for biomarker discovery.

Secreted osteopontin is highly polymerized in human airways and fragmented in asthmatic airway secretions.

Directory of Open Access Journals (Sweden)

Mehrdad Arjomandi

Full Text Available Osteopontin (OPN is a member of the small integrin-binding ligand N-linked glycoprotein (SIBLING family and a cytokine with diverse biologic roles. OPN undergoes extensive post-translational modifications, including polymerization and proteolytic fragmentation, which alters its biologic activity. Recent studies suggest that OPN may contribute to the pathogenesis of asthma.To determine whether secreted OPN (sOPN is polymerized in human airways and whether it is qualitatively different in asthma, we used immunoblotting to examine sOPN in bronchoalveolar lavage (BAL fluid samples from 12 healthy and 21 asthmatic subjects (and in sputum samples from 27 healthy and 21 asthmatic subjects. All asthmatic subjects had mild to moderate asthma and abstained from corticosteroids during the study. Furthermore, we examined the relationship between airway sOPN and cellular inflammation.We found that sOPN in BAL fluid and sputum exists in polymeric, monomeric, and cleaved forms, with most of it in polymeric form. Compared to healthy subjects, asthmatic subjects had proportionately less polymeric sOPN and more monomeric and cleaved sOPN. Polymeric sOPN in BAL fluid was associated with increased alveolar macrophage counts in airways in all subjects.These results suggest that sOPN in human airways (1 undergoes extensive post-translational modification by polymerization and proteolytic fragmentation, (2 is more fragmented and less polymerized in subjects with mild to moderate asthma, and (3 may contribute to recruitment or survival of alveolar macrophages.

Homologous and heterologous antibody responses of mice immunized with purified feline herpesvirus type 1 and canine herpesvirus glycoproteins.

Science.gov (United States)

Limcumpao, J A; Horimoto, T; Xuan, X N; Tohya, Y; Azetaka, M; Takahashi, E; Mikami, T

1991-06-01

The three glycoproteins each of feline herpesvirus type 1 (FHV-1) and canine herpesvirus (CHV) were purified by affinity chromatography using glycoprotein-specific monoclonal antibodies and used individually or in combination in immunizing mice to determine their relative immunogenicity. All the glycoproteins induced detectable virus neutralizing antibodies to the homologous virus but FHV-1 gp143/108 and its cross-reacting counterpart, CHV gp145/112, elicited the highest titers not only to the homologous virus but to the heterologous virus as well. The production of ELISA antibodies after glycoprotein immunization was variable, while hemagglutination-inhibiting antibodies were produced by only 1 out of 10 FHV-1 gp60-inoculated mice. In general, the antibody titers induced by CHV glycoproteins were lower than those by FHV-1 glycoproteins. These results indicate that these glycoproteins may be useful as subunit vaccines against FHV-1 and CHV infections.

Expression of the chitinase family glycoprotein YKL-40 in undifferentiated, differentiated and trans-differentiated mesenchymal stem cells.

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Daniel J Hoover

Full Text Available The glycoprotein YKL-40 (CHI3L1 is a secreted chitinase family protein that induces angiogenesis, cell survival, and cell proliferation, and plays roles in tissue remodeling and immune regulation. It is expressed primarily in cells of mesenchymal origin, is overexpressed in numerous aggressive carcinomas and sarcomas, but is rarely expressed in normal ectodermal tissues. Bone marrow-derived mesenchymal stem cells (MSCs can be induced to differentiate into various mesenchymal tissues and trans-differentiate into some non-mesenchymal cell types. Since YKL-40 has been used as a mesenchymal marker, we followed YKL-40 expression as undifferentiated MSCs were induced to differentiate into bone, cartilage, and neural phenotypes. Undifferentiated MSCs contain significant levels of YKL-40 mRNA but do not synthesize detectable levels of YKL-40 protein. MSCs induced to differentiate into chondrocytes and osteocytes soon began to express and secrete YKL-40 protein, as do ex vivo cultured chondrocytes and primary osteocytes. In contrast, MSCs induced to trans-differentiate into neurons did not synthesize YKL-40 protein, consistent with the general absence of YKL-40 protein in normal CNS parenchyma. However, these trans-differentiated neurons retained significant levels of YKL-40 mRNA, suggesting the mechanisms which prevented YKL-40 translation in undifferentiated MSCs remained in place, and that these trans-differentiated neurons differ in at least this way from neurons derived from neuronal stem cells. Utilization of a differentiation protocol containing β-mercaptoethanol resulted in cells that expressed significant amounts of intracellular YKL-40 protein that was not secreted, which is not seen in normal cells. Thus the synthesis of YKL-40 protein is a marker for MSC differentiation into mature mesenchymal phenotypes, and the presence of untranslated YKL-40 mRNA in non-mesenchymal cells derived from MSCs reflects differences between differentiated and

Bioactivity of proteins isolated from Lactobacillus plantarum L67 treated with Zanthoxylum piperitum DC glycoprotein.

Science.gov (United States)

Song, S; Oh, S; Lim, K-T

2015-06-01

Lactobacilli in the human gastrointestinal tract have beneficial effects on the health of their host. To enhance these effects, the bioactivity of lactobacilli can be fortified through exogenous dietary or pharmacological agents, such as glycoproteins. To elucidate the inductive effect of Zanthoxylum piperitum DC (ZPDC) glycoprotein on Lactobacillus plantarum L67, we evaluated the radical-scavenging activity, anti-oxidative enzymes (SOD, GPx and CAT), growth rate, ATPase activity and β-galactosidase activity of this strain. When Lact. plantarum L67 was treated with ZPDC glycoprotein at different concentrations, the intensities of a few SDS-PAGE bands were slightly changed. The amount of a 23 kDa protein was increased upon treatment with increasing concentrations of ZPDC glycoprotein. The results of this study indicate that the radical-scavenging activity for O2(-) and OH¯, but not for the DPPH radical, increased in a concentration-dependent manner after treatment with ZPDC glycoprotein. The activation of anti-oxidative enzymes (SOD, GPx and CAT), growth rate and β-galactosidase activity also increased in a concentration-dependent manner in response to ZPDC glycoprotein treatment, whereas ATPase activity was decreased. In summary, ZPDC glycoprotein stimulated an increase in the bioactivity of Lact. plantarum L67. Significance and impact of the study: This study demonstrated that Lactobacillus plantarum L67 possesses anti-oxidative activity. This strain of lactic bacteria has been known to have various probiotic uses, such as yogurt starters and dietary additional supplements. We found, through this experiment, that the protein has a strong anti-oxidative character, and the activity can be enhanced by treatment with Zanthoxylum piperitum DC (ZPDC) glycoprotein. This study may be application of Lact. plantarum L67 treated by ZPDC glycoprotein in yogurt fermentation. It could be one of the avenues of minimizing yogurt postacidification during storage. In addition

The haemagglutination activity of equine herpesvirus type 1 glycoprotein C.

Science.gov (United States)

Andoh, Kiyohiko; Hattori, Shiho; Mahmoud, Hassan Y A H; Takasugi, Maaya; Shimoda, Hiroshi; Bannai, Hiroshi; Tsujimura, Koji; Matsumura, Tomio; Kondo, Takashi; Kirisawa, Rikio; Mochizuki, Masami; Maeda, Ken

2015-01-02

Equine herpesvirus type 1 (EHV-1) has haemagglutination (HA) activity toward equine red blood cells (RBCs), but the identity of its haemagglutinin is unknown. To identify the haemagglutinin of EHV-1, the major glycoproteins of EHV-1 were expressed in 293T cells, and the cells or cell lysates were mixed with equine RBCs. The results showed that only EHV-1 glycoprotein C (gC)-producing cells adsorbed equine RBCs, and that the lysate of EHV-1 gC-expressing cells agglutinated equine RBCs. EHV-1 lacking gC did not show HA activity. HA activity was inhibited by monoclonal antibodies (MAbs) specific for gC, but not by antibodies directed against other glycoproteins. In addition, HA activity was not inhibited by the addition of heparin. These results indicate that EHV-1 gC can bind equine RBCs irrespective of heparin, in contrast to other herpesvirus gC proteins. Copyright © 2014 Elsevier B.V. All rights reserved.

Australine, a pyrrolizidine alkaloid that inhibits amyloglucosidase and glycoprotein processing

Energy Technology Data Exchange (ETDEWEB)

Tropea, J.E.; Molyneux, R.J.; Kaushal, G.P.; Pan, Y.T.; Mitchell, M.; Elbein, A.D. (Univ. of Texas Health Science Center, San Antonio (USA))

1989-03-07

Australine is a polyhydroxylated pyrrolizidine alkaloid that was isolated from the seeds of the Australian tree Castanospermum australe and characterized by NMR and X-ray diffraction analysis. Since swainsonine and catanospermine are polyhydroxylated indolizidine alkaloids that inhibit specific glycosidases, the authors tested australine against a variety of exoglycosidases to determine whether it would inhibit any of these enzymes. This alkaloid proved to be a good inhibitor of the {alpha}-glucosidase amyloglucosidase (50% inhibition at 5.8 {mu}M), but it did not inhibit {beta}-glucosidase, {alpha}- or {beta}-mannosidase, or {alpha}- or {beta}-galactosidase. The inhibition of amyloglucosidase was of a competitive nature. Australine also inhibited the glycoprotein processing enzyme glucosidase I, but had only slight activity toward glucosidase II. When incubated with cultured cells, this alkaloid inhibited glycoprotein processing at the glucosidase I step and caused the accumulation of glycoproteins with Glc{sub 3}Man{sub 7-9}(GlcNAc){sub 2}-oligosaccharides.

The effect of P-glycoprotein on methadone hydrochloride flux in equine intestinal mucosa.

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Linardi, R L; Stokes, A M; Andrews, F M

2013-02-01

Methadone is an effective analgesic opioid that may have a place for the treatment of pain in horses. However, its absorption seems to be impaired by the presence of a transmembrane protein, P-glycoprotein, present in different tissues including the small intestine in other species. This study aims to determine the effect of the P-glycoprotein on methadone flux in the equine intestinal mucosa, as an indicator of in vivo drug absorption. Jejunum tissues from five horses were placed into the Ussing chambers and exposed to methadone solution in the presence or absence of Rhodamine 123 or verapamil. Electrical measurements demonstrated tissue viability for 120 min, and the flux of methadone across the jejunal membrane (mucosal to submucosal direction) was calculated based on the relative drug concentration measured by ELISA. The flux of methadone was significantly higher only in the presence of verapamil. P-glycoprotein was immunolocalized in the apical membrane of the jejunal epithelial cells (enterocytes), mainly located in the tip of the villi compared to cells of the crypts. P-glycoprotein is present in the equine jejunum and may possibly mediate the intestinal transport of methadone. This study suggests that P-glycoprotein may play a role in the poor intestinal absorption of methadone in vivo. © 2012 Blackwell Publishing Ltd.

[Pregnancy-specific beta-glycoprotein in the serum of women with a complicated early pregnancy].

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Radikov, N

1989-01-01

The author determined pregnancy specific beta 1-glycoprotein in 109 women with threatened early pregnancy as 32 of the women suffered from abortus imminens with several unsuccessful pregnancies in the past as well as 67 women with abortus incipiens with bleeding ex utero. The author established that 87% of women with abortus imminens and preserved pregnancies had values of beta 1-glycoprotein close to those of normal pregnancy for the respective gestational week. 93% of women with abortus incipiens preserved pregnancies till term, but the specific glycoprotein was with in normal ranges. Spontaneous abortion occurred in 7% of women with low values under the 10th percentile. The present study show that examination of pregnancy specific beta 1-glycoprotein in women with threatened early pregnancy is of prognostic significance for the outcome of pregnancy.

Study on the extraction and purification of glycoprotein from the yellow seahorse, Hippocampus kuda Bleeker

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Su, Yuting; Xu, Yongjian

2015-01-01

The optimum parameters of extraction for glycoprotein from seahorse were examined and determined by Box-Behnken combined with ultrasonic extraction technology. Column chromatography of glycoprotein was used for further purification. The optimal extraction conditions of seahorse glycoprotein were extracting time 4.3 h, salt concentration 0.08 mol/L, extracting temperature 73°C, raw material, and water ratio 1:6. At the optimal conditions, the yield of saccharide reached to 1.123%, and the yield of protein reached to 5.898%. For purifying the crude glycoprotein, the stage renounces of DEAE-52 column chromatography were done, respectively, with 0.05, 0.1, 0.5 mol/L NaHCO3 solution, and further purification was done with Sephadex G-100 column chromatography. Finally, two pieces of seahorse glycoprotein were obtained by the column chromatography, that is, HG-11 and HG-21. The saccharide content was 56.7975% and 39.479%, the protein content was 30.5475% and 51.747%, respectively. PMID:26288722

Improved radioimmunoassay for urinary Tamm-Horsfall glycoprotein. Investigation and resolution of factors affecting its quantification

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Dawney, A B.St.J.; Thornley, C; Cattell, W R [Saint Bartholomew' s Hospital, London (UK)

1982-09-15

A rapid specific radioimmunoassay has been used to measure Tamm-Horsfall glycoprotein (TH glycoprotein) in urine, and the method described. The apparent concentration increased with increasing dilution of urine in water, reaching a plateau at 1 in 20. This increase was greater the higher the osmolality and TH glycoprotein concentration and the lower the pH of the original sample. The apparent concentration of TH glycoprotein in neat or diluted urine was not affected by freezing or by storage at 4/sup 0/C or room temperature for at least 2 days. A physiological range for the urinary excretion rate was established as 22-56 mg/24h, (considerably higher than the amount present in serum) based on samples from 29 individuals with normal renal function, as defined by their creatinine clearance. There was no significant correlation between serum concentrations of TH glycoprotein and its urinary excretion rate, nor between urinary excretion rate and creatinine clearance.

A novel PET imaging protocol identifies seizure-induced regional overactivity of P-glycoprotein at the blood-brain barrier

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Bankstahl, Jens P.; Bankstahl, Marion; Kuntner, Claudia; Stanek, Johann; Wanek, Thomas; Meier, Martin; Ding, Xiao-Qi; Müller, Markus; Langer, Oliver; Löscher, Wolfgang

2013-01-01

About one third of epilepsy patients are pharmacoresistant. Overexpression of P-glycoprotein and other multidrug transporters at the blood-brain barrier is thought to play an important role in drug-refractory epilepsy. Thus, quantification of regionally different P-glycoprotein activity in the brain in vivo is essential to identify P-glycoprotein overactivity as the relevant mechanism for drug-resistance in an individual patient. Using the radiolabeled P-glycoprotein substrate (R)-[11C]verapamil and different doses of co-administered tariquidar, which is an inhibitor of P-glycoprotein, we evaluated whether small-animal positron emission tomography (PET) can quantify regional changes in transporter function in the rat brain at baseline and 48 h after a pilocarpine-induced status epilepticus. P-glycoprotein expression was additionally quantified by immunohistochemistry. To reveal putative seizure-induced changes in blood-brain barrier integrity, we performed gadolinium-enhanced magnetic resonance scans on a 7.0 Tesla small-animal scanner. Before P-glycoprotein modulation, brain uptake of (R)-[11C]verapamil was low in all regions investigated in control and post-status epilepticus rats. After administration of 3 mg/kg tariquidar, which inhibits P-glycoprotein only partially, we observed increased regional differentiation in brain activity uptake in post-status epilepticus versus control rats, which diminished after maximal P-glycoprotein inhibition. Regional increases in the efflux rate constant k2, but not in distribution volume VT or influx rate constant K1, correlated significantly with increases in P-glycoprotein expression measured by immunohistochemistry. This imaging protocol proves to be suitable to detect seizure-induced regional changes in P-glycoprotein activity and is readily applicable to humans, with the aim to detect relevant mechanisms of pharmacoresistance in epilepsy in vivo. PMID:21677164

Interleukin-17A induces bicarbonate secretion in normal human bronchial epithelial cells

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Kreindler, James L.; Bertrand, Carol A.; Lee, Robert J.; Karasic, Thomas; Aujla, Shean; Pilewski, Joseph M.; Frizzell, Raymond A.; Kolls, Jay K.

2009-01-01

The innate immune functions of human airways include mucociliary clearance and antimicrobial peptide activity. Both functions may be affected by changes in epithelial ion transport. Interleukin-17A (IL-17A), which has a receptor at the basolateral membrane of airway epithelia, is a T cell cytokine that has been shown to increase mucus secretion and antimicrobial peptide production by human bronchial epithelial (HBE) cells. Furthermore, IL-17A levels are increased in sputum from patients during pulmonary exacerbations of cystic fibrosis. Therefore, we investigated the effects of IL-17A on basal, amiloride-sensitive, and forskolin-stimulated ion transport in mature, well-differentiated HBE cells. Exposure of HBE monolayers to IL-17A for 48 h induced a novel forskolin-stimulated bicarbonate secretion in addition to forskolin-stimulated chloride secretion and resulted in alkalinization of liquid on the mucosal surface of polarized cells. IL-17A-induced bicarbonate secretion was cystic fibrosis transmembrane conductance regulator (CFTR)-dependent, mucosal chloride-dependent, partially Na+-dependent, and sensitive to serosal, but not mucosal, stilbene inhibition. These data suggest that IL-17A modulates epithelial bicarbonate secretion and implicate a mechanism by which airway surface liquid pH changes may be abnormal in cystic fibrosis. PMID:19074559

Fbs1 protects the malfolded glycoproteins from the attack of peptide:N-glycanase

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Yamaguchi, Yoshiki; Hirao, Takeshi; Sakata, Eri; Kamiya, Yukiko; Kurimoto, Eiji; Yoshida, Yukiko; Suzuki, Tadashi; Tanaka, Keiji; Kato, Koichi

2007-01-01

Fbs1 is a cytosolic lectin putatively operating as a chaperone as well as a substrate-recognition subunit of the SCF Fbs1 ubiquitin ligase complex. To provide structural and functional basis of preferential binding of Fbs1 to unfolded glycoproteins, we herein characterize the interaction of Fbs1 with a heptapeptide carrying Man 3 GlcNAc 2 by nuclear magnetic resonance (NMR) spectroscopy and other biochemical methods. Inspection of the NMR data obtained by use of the isotopically labeled glycopeptide indicated that Fbs1 interacts with sugar-peptide junctions, which are shielded in native glycoprotein, in many cases, but become accessible to Fbs1 in unfolded glycoproteins. Furthermore, Fbs1 was shown to inhibit deglycosylation of denatured ribonuclease B by a cytosolic peptide:N-glycanase (PNGase). On the basis of these data, we suggest that Fbs1 captures malfolded glycoproteins, protecting them from the attack of PNGase, during the chaperoning or ubiquitinating operation in the cytosol

Sphingomyelin synthases regulate protein trafficking and secretion.

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Marimuthu Subathra

Full Text Available Sphingomyelin synthases (SMS1 and 2 represent a class of enzymes that transfer a phosphocholine moiety from phosphatidylcholine onto ceramide thus producing sphingomyelin and diacylglycerol (DAG. SMS1 localizes at the Golgi while SMS2 localizes both at the Golgi and the plasma membrane. Previous studies from our laboratory showed that modulation of SMS1 and, to a lesser extent, of SMS2 affected the formation of DAG at the Golgi apparatus. As a consequence, down-regulation of SMS1 and SMS2 reduced the localization of the DAG-binding protein, protein kinase D (PKD, to the Golgi. Since PKD recruitment to the Golgi has been implicated in cellular secretion through the trans golgi network (TGN, the effect of down-regulation of SMSs on TGN-to-plasma membrane trafficking was studied. Down regulation of either SMS1 or SMS2 significantly retarded trafficking of the reporter protein vesicular stomatitis virus G protein tagged with GFP (VSVG-GFP from the TGN to the cell surface. Inhibition of SMSs also induced tubular protrusions from the trans Golgi network reminiscent of inhibited TGN membrane fission. Since a recent study demonstrated the requirement of PKD activity for insulin secretion in beta cells, we tested the function of SMS in this model. Inhibition of SMS significantly reduced insulin secretion in rat INS-1 cells. Taken together these results provide the first direct evidence that both enzymes (SMS1 and 2 are capable of regulating TGN-mediated protein trafficking and secretion, functions that are compatible with PKD being a down-stream target for SMSs in the Golgi.

Purification and characterization of a soluble glycoprotein from garlic (Allium sativum) and its in vitro bioactivity.

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Wang, Yan; Zou, Tingting; Xiang, Minghui; Jin, Chenzhong; Zhang, Xuejiao; Chen, Yong; Jiang, Qiuqing; Hu, Yihong

2016-10-02

A soluble glycoprotein was purified to homogeneity from ripe garlic (Allium sativum) bulbs using ammonium sulfate precipitation, Sephadex G-100 gel filtration, and diethylaminoethyl-52 cellulose anion-exchange chromatography. A native mass of 55.7 kDa estimated on gel permeation chromatography and a molecular weight of 13.2 kDa observed on sodium dodecyl sulfate-polyacrylamide gel electrophoresis supported that the glycoprotein is a homotetramer. β-Elimination reaction result suggested that the glycoprotein is an N-linked type. Fourier-transform infrared spectroscopy proved that it contains sugar. Gas chromatography-mass spectrometer analysis showed that its sugar component was galactose. The glycoprotein has 1,1-diphenyl-2-picrylhydrazil free radical scavenging activity and the peroxidation inhibition ability to polyunsaturated fatty acid. These results indicated that the glycoprotein has potential for food additives, functional foods, and even biotechnological and medical applications.

LcrG secretion is not required for blocking of Yops secretion in Yersinia pestis

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Matson Jyl S

2008-02-01

Full Text Available Abstract Background LcrG, a negative regulator of the Yersinia type III secretion apparatus has been shown to be primarily a cytoplasmic protein, but is secreted at least in Y. pestis. LcrG secretion has not been functionally analyzed and the relevance of LcrG secretion on LcrG function is unknown. Results An LcrG-GAL4AD chimera, originally constructed for two-hybrid analyses to analyze LcrG protein interactions, appeared to be not secreted but the LcrG-GAL4AD chimera retained the ability to regulate Yops secretion. This result led to further investigation to determine the significance of LcrG secretion on LcrG function. Additional analyses including deletion and substitution mutations of amino acids 2–6 in the N-terminus of LcrG were constructed to analyze LcrG secretion and LcrG's ability to control secretion. Some changes to the N-terminus of LcrG were found to not affect LcrG's secretion or LcrG's secretion-controlling activity. However, substitution of poly-isoleucine in the N-terminus of LcrG did eliminate LcrG secretion but did not affect LcrG's secretion controlling activity. Conclusion These results indicate that secretion of LcrG, while observable and T3SS mediated, is not relevant for LcrG's ability to control secretion.

Tamper-proof secret image-sharing scheme for identifying cheated secret keys and shared images

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Chen, Chien-Chang; Liu, Chong-An

2013-01-01

A (t,n) secret image-sharing scheme shares a secret image to n participants, and the t users recover the image. During the recovery procedure of a conventional secret image-sharing scheme, cheaters may use counterfeit secret keys or modified shared images to cheat other users' secret keys and shared images. A cheated secret key or shared image leads to an incorrect secret image. Unfortunately, the cheater cannot be identified. We present an exponent and modulus-based scheme to provide a tamper-proof secret image-sharing scheme for identifying cheaters on secret keys or shared images. The proposed scheme allows users to securely select their secret key. This assignment can be performed over networks. Modulus results of each shared image is calculated to recognize cheaters of a shared image. Experimental results indicate that the proposed scheme is excellent at identifying cheated secret keys and shared images.

Annotating Human P-Glycoprotein Bioassay Data.

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Zdrazil, Barbara; Pinto, Marta; Vasanthanathan, Poongavanam; Williams, Antony J; Balderud, Linda Zander; Engkvist, Ola; Chichester, Christine; Hersey, Anne; Overington, John P; Ecker, Gerhard F

2012-08-01

Huge amounts of small compound bioactivity data have been entering the public domain as a consequence of open innovation initiatives. It is now the time to carefully analyse existing bioassay data and give it a systematic structure. Our study aims to annotate prominent in vitro assays used for the determination of bioactivities of human P-glycoprotein inhibitors and substrates as they are represented in the ChEMBL and TP-search open source databases. Furthermore, the ability of data, determined in different assays, to be combined with each other is explored. As a result of this study, it is suggested that for inhibitors of human P-glycoprotein it is possible to combine data coming from the same assay type, if the cell lines used are also identical and the fluorescent or radiolabeled substrate have overlapping binding sites. In addition, it demonstrates that there is a need for larger chemical diverse datasets that have been measured in a panel of different assays. This would certainly alleviate the search for other inter-correlations between bioactivity data yielded by different assay setups.

Wrapped up in Covers: Preschoolers' Secrets and Secret Hiding Places

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Corson, Kimberly; Colwell, Malinda J.; Bell, Nancy J.; Trejos-Castillo, Elizabeth

2014-01-01

In this qualitative study, interviews about children's secret hiding places were conducted with 3-5-year-olds (n?=?17) in a university sponsored preschool programme using art narratives. Since prior studies indicate that children understand the concept of a secret as early as five and that they associate secrets with hiding places, the purpose of…

Chemoenzymatic site-specific labeling of influenza glycoproteins as a tool to observe virus budding in real time.

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Maximilian Wei-Lin Popp

Full Text Available The influenza virus uses the hemagglutinin (HA and neuraminidase (NA glycoproteins to interact with and infect host cells. While biochemical and microscopic methods allow examination of the early steps in flu infection, the genesis of progeny virions has been more difficult to follow, mainly because of difficulties inherent in fluorescent labeling of flu proteins in a manner compatible with live cell imaging. We here apply sortagging as a chemoenzymatic approach to label genetically modified but infectious flu and track the flu glycoproteins during the course of infection. This method cleanly distinguishes influenza glycoproteins from host glycoproteins and so can be used to assess the behavior of HA or NA biochemically and to observe the flu glycoproteins directly by live cell imaging.

Intestinal mucus and juice glycoproteins have a liquid crystalline structure

International Nuclear Information System (INIS)

Denisova, E.A.; Lazarev, P.I.; Vazina, A.A.; Zheleznaya, L.A.

1985-01-01

X-ray diffraction patterns have been obtained from the following components of canine gastrointestinal tract: (1) native small intestine mucus layer; (2) the precipitate of the flocks formed in the duodenal juice with decreasing pH; (3) concentrated solutions of glycoproteins isolated from the duodenal juice. The X-ray patterns consist of a large number of sharp reflections of spacings between about 100 and 4 A. Some reflections are common for all components studied. All the patterns are interpreted as arising from the glycoprotein molecules ordered into a liquid crystalline structure. (author)

HK2 Proximal Tubule Epithelial Cells Synthesize and Secrete Plasma Proteins Predominantly Through the Apical Surface.

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Zhao, Ke-Wei; Murray, Elsa J Brochmann; Murray, Samuel S

2017-04-01

Renal proximal tubule epithelial cells (PTECs) are known to reabsorb salts and small plasma proteins filtered through Bowman's capsule. Following acute kidney injury, PTECs assume some characteristics of hepatocytes in producing various plasma proteins. We now demonstrate that even at a resting state, a PTEC cell line, HK2 expresses mRNAs for and synthesizes and secretes plasma proteins in a complex with complement C3, an α 2 -macroglobulin family chaperone, including albumin, transferrin, α 1 -antitrypsin, α 1 -antichymotrypsin, α 2 -HS-glycoprotein, ceruloplasmin, haptoglobin, C1-inhibitor, secreted phosphoprotein-24, and insulin-like growth factor-1. When grown on transwell inserts, HK2 cells predominantly secrete (∼90%) plasma proteins into the apical side and a smaller fraction into the basolateral side as determined by ELISA assays. When cultured in the presence of exogenous cytokines such as IL1β, IL6, TNFα, BMP2, or TGFβ1, HK2 cell mRNA expressions for plasma proteins were variably affected whereas basolateral secretions were elevated to or in excess of those of the apical level. In addition, HK2 cells produce proTGFβ1 with its intact N-terminal latency associated peptide and latent-TGF-β-binding proteins. The complex cannot be dissociated under conditions of SDS, heating, and electrophoresis. Moreover, HK2 cells maintain their ability to quickly uptake exogenously added serum proteins from the culture medium, as if they are recognized differently by the endocytic receptors. These results provide new insight into the hepatization of PTECs. In addition to their unique uptake of plasma proteins and salts from the filtrate, they are a source of urinary proteins under normal conditions as wells as in chronic and acute kidney diseases. J. Cell. Biochem. 118: 924-933, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Platelet Glycoprotein Ib-IX and Malignancy

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2010-09-01

provide a unique microenvironment supporting the accumulation of more platelets and the elaboration of a fibrin - rich network produced by coagulation...process and can initiate the formation of a platelet - rich thrombus by tethering the platelet to a thrombogenic surface. Several ligands binding to GP Ib... Platelet Glycoprotein Ib-IX and Malignancy PRINCIPAL INVESTIGATOR: Jerry Ware, Ph.D

Tolerogenic β2-glycoprotein I DNA vaccine and FK506 as an adjuvant attenuates experimental obstetric antiphospholipid syndrome.

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Chao, Ya-Hsuan; Chen, Der-Yuan; Lan, Joung-Liang; Tang, Kuo-Tung; Lin, Chi-Chien

2018-01-01

DNA vaccines have recently emerged as a therapeutic agent for treating autoimmune diseases, such as multiple sclerosis. Antiphospholipid antibody syndrome (APS) is an autoimmune disease characterized by β2-glycoprotein I (β2-GPI)-targeting antiphospholipid antibodies (APAs) and vascular thrombosis or obstetrical complications. To examine the therapeutic potential of a β2-GPI DNA vaccine, we administered a vaccine mixed with FK506 as an adjuvant to a mouse model of obstetric APS. First, the pCMV3-β2-GPI DNA vaccine, which encodes the full-length human β2-GPI gene, was constructed. Then, we administered the β2-GPI DNA vaccine in 0.1 ml of saline, mixed with or without 100 μg of FK506, intramuscularly to the mice on days 28, 35 and 42. Blood titers of the anti-β2-GPI antibody, platelet counts, activated partial thromboplastin times (aPTTs), and the percentage of fetal loss were measured. We also stimulated murine splenic T cells ex vivo with β2-GPI and determined the T helper cell proportion and cytokine secretion. The administration of the β2-GPI DNA vaccine mixed with FK506 reduced the blood IgG anti-β2-GPI antibody titers and suppressed APS manifestations in mice. The combination also suppressed interferon-γ and interleukin (IL)-17A secretion but increased the Treg cell proportion and IL-10 secretion in murine splenic T cells following ex vivo stimulation with β2-GPI. Our results demonstrated the therapeutic efficacy of a β2-GPI DNA vaccine and FK506 as an adjuvant in a murine model of obstetric APS. Possible mechanisms include the inhibition of Th1 and Th17 responses and the up-regulation of Treg cells.

C-terminus glycans with critical functional role in the maturation of secretory glycoproteins.

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Daniela Cioaca

Full Text Available The N-glycans of membrane glycoproteins are mainly exposed to the extracellular space. Human tyrosinase is a transmembrane glycoprotein with six or seven bulky N-glycans exposed towards the lumen of subcellular organelles. The central active site region of human tyrosinase is modeled here within less than 2.5 Å accuracy starting from Streptomyces castaneoglobisporus tyrosinase. The model accounts for the last five C-terminus glycosylation sites of which four are occupied and indicates that these cluster in two pairs--one in close vicinity to the active site and the other on the opposite side. We have analyzed and compared the roles of all tyrosinase N-glycans during tyrosinase processing with a special focus on the proximal to the active site N-glycans, s6:N337 and s7:N371, versus s3:N161 and s4:N230 which decorate the opposite side of the domain. To this end, we have constructed mutants of human tyrosinase in which its seven N-glycosylation sites were deleted. Ablation of the s6:N337 and s7:N371 sites arrests the post-translational productive folding process resulting in terminally misfolded mutants subjected to degradation through the mannosidase driven ERAD pathway. In contrast, single mutants of the other five N-glycans located either opposite to the active site or into the N-terminus Cys1 extension of tyrosinase are temperature-sensitive mutants and recover enzymatic activity at the permissive temperature of 31°C. Sites s3 and s4 display selective calreticulin binding properties. The C-terminus sites s7 and s6 are critical for the endoplasmic reticulum retention and intracellular disposal. Results herein suggest that individual N-glycan location is critical for the stability, regional folding control and secretion of human tyrosinase and explains some tyrosinase gene missense mutations associated with oculocutaneous albinism type I.

The quality control of glycoprotein folding in the endoplasmic reticulum, a trip from trypanosomes to mammals

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A.J. Parodi

1998-05-01

Full Text Available The present review deals with the stages of synthesis and processing of asparagine-linked oligosaccharides occurring in the lumen of the endoplasmic reticulum and their relationship to the acquisition by glycoproteins of their proper tertiary structures. Special emphasis is placed on reactions taking place in trypanosomatid protozoa since their study has allowed the detection of the transient glucosylation of glycoproteins catalyzed by UDP-Glc:glycoprotein glucosyltransferase and glucosidase II. The former enzyme has the unique property of covalently tagging improperly folded conformations by catalyzing the formation of protein-linked Glc1Man7GlcNAc2, Glc1Man8GlcNac2 and Glc1Man9GlcNAc2 from the unglucosylated proteins. Glucosyltransferase is a soluble protein of the endoplasmic reticulum that recognizes protein domains exposed in denatured but not in native conformations (probably hydrophobic amino acids and the innermost N-acetylglucosamine unit that is hidden from macromolecular probes in most native glycoproteins. In vivo, the glucose units are removed by glucosidase II. The influence of oligosaccharides in glycoprotein folding is reviewed as well as the participation of endoplasmic reticulum chaperones (calnexin and calreticulin that recognize monoglucosylated species in the same process. A model for the quality control of glycoprotein folding in the endoplasmic reticulum, i.e., the mechanism by which cells recognize the tertiary structure of glycoproteins and only allow transit to the Golgi apparatus of properly folded species, is discussed. The main elements of this control are calnexin and calreticulin as retaining components, the UDP-Glc:glycoprotein glucosyltransferase as a sensor of tertiary structures and glucosidase II as the releasing agent.

Boronic Acid-Based Approach for Separation and Immobilization of Glycoproteins and Its Application in Sensing

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Lin Liu

2013-10-01

Full Text Available Glycoproteins influence a broad spectrum of biological processes including cell-cell interaction, host-pathogen interaction, or protection of proteins against proteolytic degradation. The analysis of their glyco-structures and concentration levels are increasingly important in diagnosis and proteomics. Boronic acids can covalently react with cis-diols in the oligosaccharide chains of glycoproteins to form five- or six-membered cyclic esters. Based on this interaction, boronic acid-based ligands and materials have attracted much attention in both chemistry and biology as the recognition motif for enrichment and chemo/biosensing of glycoproteins in recent years. In this work, we reviewed the progress in the separation, immobilization and detection of glycoproteins with boronic acid-functionalized materials and addressed its application in sensing.

Salmonella-secreted Virulence Factors

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Heffron, Fred; Niemann, George; Yoon, Hyunjin; Kidwai, Afshan S.; Brown, Roslyn N.; McDermott, Jason E.; Smith, Richard D.; Adkins, Joshua N.

2011-05-01

In this short review we discuss secreted virulence factors of Salmonella, which directly affect Salmonella interaction with its host. Salmonella secretes protein to subvert host defenses but also, as discussed, to reduce virulence thereby permitting the bacteria to persist longer and more successfully disperse. The type III secretion system (TTSS) is the best known and well studied of the mechanisms that enable secretion from the bacterial cytoplasm to the host cell cytoplasm. Other secretion systems include outer membrane vesicles, which are present in all Gram-negative bacteria examined to date, two-partner secretion, and type VI secretion will also be addressed. Excellent reviews of Salmonella secreted effectors have focused on themes such as actin rearrangements, vesicular trafficking, ubiquitination, and the activities of the virulence factors themselves. This short review is based on S. Typhimurium infection of mice because it is a model of typhoid like disease in humans. We have organized effectors in terms of events that happen during the infection cycle and how secreted effectors may be involved.

Melanocyte-secreted fibromodulin promotes an angiogenic microenvironment.

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Adini, Irit; Ghosh, Kaustabh; Adini, Avner; Chi, Zai-Long; Yoshimura, Takeru; Benny, Ofra; Connor, Kip M; Rogers, Michael S; Bazinet, Lauren; Birsner, Amy E; Bielenberg, Diane R; D'Amato, Robert J

2014-01-01

Studies have established that pigmentation can provide strong, protective effects against certain human diseases. For example, angiogenesis-dependent diseases such as wet age-related macular degeneration and infantile hemangioma are more common in light-skinned individuals of mixed European descent than in African-Americans. Here we found that melanocytes from light-skinned humans and albino mice secrete high levels of fibromodulin (FMOD), which we determined to be a potent angiogenic factor. FMOD treatment stimulated angiogenesis in numerous in vivo systems, including laser-induced choroidal neovascularization, growth factor-induced corneal neovascularization, wound healing, and Matrigel plug assays. Additionally, FMOD enhanced vascular sprouting during normal retinal development. Deletion of Fmod in albino mice resulted in a marked reduction in the amount of neovascularization induced by retinal vein occlusion, corneal growth factor pellets, and Matrigel plugs. Our data implicate the melanocyte-secreted factor FMOD as a key regulator of angiogenesis and suggest an underlying mechanism for epidemiological differences between light-skinned individuals of mixed European descent and African-Americans. Furthermore, inhibition of FMOD in humans has potential as a therapeutic strategy for treating angiogenesis-dependent diseases.

Mechanism of Action of Secreted Newt Anterior Gradient Protein.

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Kathrin S Grassme

Full Text Available Anterior gradient (AG proteins have a thioredoxin fold and are targeted to the secretory pathway where they may act in the ER, as well as after secretion into the extracellular space. A newt member of the family (nAG was previously identified as interacting with the GPI-anchored salamander-specific three-finger protein called Prod1. Expression of nAG has been implicated in the nerve dependence of limb regeneration in salamanders, and nAG acted as a growth factor for cultured newt limb blastemal (progenitor cells, but the mechanism of action was not understood. Here we show that addition of a peptide antibody to Prod1 specifically inhibit the proliferation of blastema cells, suggesting that Prod1 acts as a cell surface receptor for secreted nAG, leading to S phase entry. Mutation of the single cysteine residue in the canonical active site of nAG to alanine or serine leads to protein degradation, but addition of residues at the C terminus stabilises the secreted protein. The mutation of the cysteine residue led to no detectable activity on S phase entry in cultured newt limb blastemal cells. In addition, our phylogenetic analyses have identified a new Caudata AG protein called AG4. A comparison of the AG proteins in a cell culture assay indicates that nAG secretion is significantly higher than AGR2 or AG4, suggesting that this property may vary in different members of the family.

Bicarbonate-dependent secretion and proteolytic processing of recombinant myocilin.

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José-Daniel Aroca-Aguilar

Full Text Available Myocilin is an extracellular glycoprotein of poorly understood function. Mutations of this protein are involved in glaucoma, an optic neuropathy characterized by a progressive and irreversible visual loss and frequently associated with elevated intraocular pressure. We previously showed that recombinant myocilin undergoes an intracellular proteolytic processing by calpain II which cleaves the central region of the protein, releasing one N- and one C-terminal fragment. Myocilin cleavage is reduced by glaucoma mutations and it has been proposed to participate in intraocular pressure modulation. To identify possible factors regulating the proteolytic processing of recombinant myocilin, we used a cellular model in which we analyzed how different culture medium parameters (i.e., culture time, cell density, pH, bicarbonate concentration, etc. affect the presence of the extracellular C-terminal fragment. Extracellular bicarbonate depletion associated with culture medium acidification produced a reversible intracellular accumulation of full-length recombinant myocilin and incremented its intracellular proteolytic processing, raising the extracellular C-terminal fragment percentage. It was also determined that myocilin intracellular accumulation depends on its N-terminal region. These data suggest that aqueous humor bicarbonate variations could also modulate the secretion and cleavage of myocilin present in ocular tissues.

Glycan structures contain information for the spatial arrangement of glycoproteins in the plasma membrane.

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M Kristen Hall

Full Text Available Glycoconjugates at the cell surface are crucial for cells to communicate with each other and the extracellular microenvironment. While it is generally accepted that glycans are vectorial biopolymers, their information content is unclear. This report provides evidence that distinct N-glycan structures influence the spatial arrangement of two integral membrane glycoproteins, Kv3.1 and E-cadherin, at the adherent membrane which in turn alter cellular properties. Distinct N-glycan structures were generated by heterologous expression of these glycoproteins in parental and glycosylation mutant Chinese hamster ovary cell lines. Unlike the N-linked glycans, the O-linked glycans of the mutant cell lines are similar to those of the parental cell line. Western and lectin blots of total membranes and GFP immunopurified samples, combined with glycosidase digestion reactions, were employed to verify the glycoproteins had predominantly complex, oligomannose, and bisecting type N-glycans from Pro(-5, Lec1, and Lec10B cell lines, respectively. Based on total internal reflection fluorescence and differential interference contrast microscopy techniques, and cellular assays of live parental and glycosylation mutant CHO cells, we propose that glycoproteins with complex, oligomannose or bisecting type N-glycans relay information for localization of glycoproteins to various regions of the plasma membrane in both a glycan-specific and protein-specific manner, and furthermore cell-cell interactions are required for deciphering much of this information. These distinct spatial arrangements also impact cell adhesion and migration. Our findings provide direct evidence that N-glycan structures of glycoproteins contribute significantly to the information content of cells.

Ebola virus glycoprotein-mediated anoikis of primary human cardiac microvascular endothelial cells

International Nuclear Information System (INIS)

Ray, Ratna B.; Basu, Arnab; Steele, Robert; Beyene, Aster; McHowat, Jane; Meyer, Keith; Ghosh, Asish K.; Ray, Ranjit

2004-01-01

Ebola virus glycoprotein (EGP) has been implicated for the induction of cytotoxicity and injury in vascular cells. On the other hand, EGP has also been suggested to induce massive cell rounding and detachment from the plastic surface by downregulating cell adhesion molecules without causing cytotoxicity. In this study, we have examined the cytotoxic role of EGP in primary endothelial cells by transduction with a replication-deficient recombinant adenovirus expressing EGP (Ad-EGP). Primary human cardiac microvascular endothelial cells (HCMECs) transduced with Ad-EGP displayed loss of cell adhesion from the plastic surface followed by cell death. Transfer of conditioned medium from EGP-transduced HCMEC into naive cells did not induce loss of adhesion or cell death, suggesting that EGP needs to be expressed intracellularly to exert its cytotoxic effect. Subsequent studies suggested that HCMEC death occurred through apoptosis. Results from this study shed light on the EGP-induced anoikis in primary human cardiac endothelial cells, which may have significant pathological consequences

Design and synthesis of an antigenic mimic of the Ebola glycoprotein

OpenAIRE

Rutledge, Ryan D.; Huffman, Brian J.; Cliffel, David E.; Wright, David W.

2008-01-01

An antigenic mimic of the Ebola glycoprotein was synthesized and tested for its ability to be recognized by an anti-Ebola glycoprotein antibody. Epitope-mapping procedures yielded a suitable epitope that, when presented on the surface of a nanoparticle, forms a structure that is recognized by an antibody specific for the native protein. This mimic-antibody interaction has been quantitated through ELISA and QCM-based methods and yielded an affinity (Kd = 12 × 10−6 M) within two orders of magni...

Meaningful Share Generation for Increased Number of Secrets in Visual Secret-Sharing Scheme

Directory of Open Access Journals (Sweden)

Mustafa Ulutas

2010-01-01

Full Text Available This paper presents a new scheme for hiding two halftone secret images into two meaningful shares created from halftone cover images. Meaningful shares are more desirable than noise-like (meaningless shares in Visual Secret Sharing because they look natural and do not attract eavesdroppers' attention. Previous works in the field focus on either increasing number of secrets or creating meaningful shares for one secret image. The method outlined in this paper both increases the number of secrets and creates meaningful shares at the same time. While the contrast ratio of shares is equal to that of Extended Visual Cryptography, two secrets are encoded into two shares as opposed to one secret in the Extended Visual Cryptography. Any two natural-looking images can be used as cover unlike the Halftone Visual Cryptography method where one cover should be the negative of the other cover image and can only encode one secret. Effectiveness of the proposed method is verified by an experiment.

On the presence of prostatic secretion protein in rat seminal fluid

International Nuclear Information System (INIS)

Borgstroem, E.; Pousette, A.; Bjoerk, P.; Hoegberg, B.; Carlstroem, K.; Sundelin, B.; Gustafsson, J.A.

1981-01-01

The copulating plug collected from the tip of the penis from rats immediately after decapitation contains a protein very similar and probably identical to PSP (prostatic secretion protein); this protein has earlier been purified from rat prostatic cytosol and characterized. The protein present in the copulating plug interacts with [3H]estramustine and binds to the antibody raised against rat PSP. The concentration of the protein in the copulating plug is 400 ng/mg of total protein, when measured using the radioimmunoassay technique developed earlier for measurement of PSP in rat prostate. The [3H]estramustine-protein complex formed in a preparation of the copulating plug has an apparent molecular weight of about 50,000 and a sedimentation coefficient of about 3S when analyzed using sucrose density gradient centrifugation. The complex was retained on Concanavalin-A Sepharose indicating that the protein is a glycoprotein. Binding of the complex was also observed on hydroxylapatite and DEAE-Sephadex columns, from which it was eluted at 0.18 M KCl. Light microscope autoradiograms of rat sperms incubated with 125I-labeled PSP indicated that PSP is bound to all parts of the sperms. A macromolecule interacting with the PSP-antibodies is also present in human seminal fluid but at a concentration considerably lower than in rat seminal fluid. The present study shows that a macromolecule probably identical to prostatic secretion protein is present in the copulating plug from the rat. The biological role of this protein in normal male fertility is discussed

Bioinformatics Analysis of Envelope Glycoprotein E epitopes of ...

African Journals Online (AJOL)

User

2011-05-02

May 2, 2011 ... 1National Centre of Excellence in Molecular Biology, University of the Punjab Lahore, Pakistan. 2Department of ..... E glycoprotein and its interaction with antibody with the method of molecular dynamics and molecular model ...

eEF-2 Phosphorylation Down-Regulates P-Glycoprotein Over-Expression in Rat Brain Microvessel Endothelial Cells.

Directory of Open Access Journals (Sweden)

Xing Hua Tang

Full Text Available We investigated whether glutamate, NMDA receptors, and eukaryote elongation factor-2 kinase (eEF-2K/eEF-2 regulate P-glycoprotein expression, and the effects of the eEF-2K inhibitor NH125 on the expression of P-glycoprotein in rat brain microvessel endothelial cells (RBMECs.Cortex was obtained from newborn Wistar rat brains. After surface vessels and meninges were removed, the pellet containing microvessels was resuspended and incubated at 37°C in culture medium. Cell viability was assessed by the MTT assay. RBMECs were identified by immunohistochemistry with anti-vWF. P-glycoprotein, phospho-eEF-2, and eEF-2 expression were determined by western blot analysis. Mdr1a gene expression was analyzed by RT-PCR.Mdr1a mRNA, P-glycoprotein and phospho-eEF-2 expression increased in L-glutamate stimulated RBMECs. P-glycoprotein and phospho-eEF-2 expression were down-regulated after NH125 treatment in L-glutamate stimulated RBMECs.eEF-2K/eEF-2 should have played an important role in the regulation of P-glycoprotein expression in RBMECs. eEF-2K inhibitor NH125 could serve as an efficacious anti-multidrug resistant agent.

Structure of a Pestivirus Envelope Glycoprotein E2 Clarifies Its Role in Cell Entry

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Kamel El Omari

2013-01-01

Full Text Available Enveloped viruses have developed various adroit mechanisms to invade their host cells. This process requires one or more viral envelope glycoprotein to achieve cell attachment and membrane fusion. Members of the Flaviviridae such as flaviviruses possess only one envelope glycoprotein, E, whereas pestiviruses and hepacivirus encode two glycoproteins, E1 and E2. Although E2 is involved in cell attachment, it has been unclear which protein is responsible for membrane fusion. We report the crystal structures of the homodimeric glycoprotein E2 from the pestivirus bovine viral diarrhea virus 1 (BVDV1 at both neutral and low pH. Unexpectedly, BVDV1 E2 does not have a class II fusion protein fold, and at low pH the N-terminal domain is disordered, similarly to the intermediate postfusion state of E2 from sindbis virus, an alphavirus. Our results suggest that the pestivirus and possibly the hepacivirus fusion machinery are unlike any previously observed.

Structure of a Pestivirus Envelope Glycoprotein E2 Clarifies Its Role in Cell Entry

Science.gov (United States)

El Omari, Kamel; Iourin, Oleg; Harlos, Karl; Grimes, Jonathan M.; Stuart, David I.

2013-01-01

Summary Enveloped viruses have developed various adroit mechanisms to invade their host cells. This process requires one or more viral envelope glycoprotein to achieve cell attachment and membrane fusion. Members of the Flaviviridae such as flaviviruses possess only one envelope glycoprotein, E, whereas pestiviruses and hepacivirus encode two glycoproteins, E1 and E2. Although E2 is involved in cell attachment, it has been unclear which protein is responsible for membrane fusion. We report the crystal structures of the homodimeric glycoprotein E2 from the pestivirus bovine viral diarrhea virus 1 (BVDV1) at both neutral and low pH. Unexpectedly, BVDV1 E2 does not have a class II fusion protein fold, and at low pH the N-terminal domain is disordered, similarly to the intermediate postfusion state of E2 from sindbis virus, an alphavirus. Our results suggest that the pestivirus and possibly the hepacivirus fusion machinery are unlike any previously observed. PMID:23273918

Frequency of anti-glycoprotein Ia/IIa (anti-HPA-5b,-5a and anti-glycoprotein IIb/IIIa (anti-HPA-1a,-3a,-4a alloantibodies in multiparous women of African descent

Directory of Open Access Journals (Sweden)

Zaccheaus A Jeremiah

2010-05-01

Full Text Available Zaccheaus A Jeremiah1, Justina E Oburu2, Osaro Erhabor1, Fiekumo I Buseri1, Teddy C Adias31Haematology and Blood Transfusion Science Unit, Department of Medical Laboratory Sciences, College of Health Sciences, Niger Delta University, Wilberforce Island, Nigeria; 2Department of Haematology and Blood Transfusion, University of Port Harcourt Teaching Hospital, Port Harcourt, Nigeria; 3Rivers State University of Science and Technology, Port Harcourt, NigeriaBackground: Human platelet antibodies are often implicated in some disease conditions, such as neonatal alloimmune thrombocytopenia (NAIT, idiopathic thrombocytopenic purpura (ITP and platelet refractoriness. The frequencies of these alloantibodies have not been reported in Nigeria and West Africa.Methods: Screening for allontibodies to human platelet antigens (HPA was undertaken using the GTI PakPlus® qualitative solid phase ELISA reagent. Platelet count was done using the ICSH approved procedure using 1% ammonium oxalate reagent.Study design: A cross-section of apparently healthy adult Nigerian multiparous non-pregnant women, who were staff of a tertiary health facility in the Niger Delta, Nigeria, were screened for alloantibodies to human platelet antigens.Results: Of the one hundred (100 women screened, the prevalence of anti-glycoprotein IIb/IIIa (anti-HPA-Ia,-3a,-4a was zero percent (0%, anti-glycoprotein Ia/IIa (anti-HPA-5b accounted for 30% of results, while anti-glycoprotein Ia/IIa (anti-HPA-5a was 18%. Parity was found to exert significant influence on the development to HPA antibodies (Fisher’s Exact Test = 11.683, P < 0.05; 13.577, P < 0.01. The platelet count of the women did not appear to exert any influence on the development of the antibodies (P > 0.05.Conclusion: This study has observed a high prevalence of anti-HPA-5b in our sample population. The prevalence of alloantibodies to HPA antigens was found to associate strongly with parity. These results indicate that there is a

Syntaxin-4 is essential for IgE secretion by plasma cells

Energy Technology Data Exchange (ETDEWEB)

Rahman, Arman; DeCourcey, Joseph; Larbi, Nadia Ben [Immunomodulation Group, School of Biotechnology, Dublin City University (Ireland); Loughran, Sinéad T.; Walls, Dermot [School of Biotechnology and National Centre for Sensor Research, Dublin City University (Ireland); Loscher, Christine E., E-mail: christine.loscher@dcu.ie [Immunomodulation Group, School of Biotechnology, Dublin City University (Ireland)

2013-10-11

Highlights: •Knock-down of syntaxin-4 in U266 plasma cells resulted in reduction of IgE secretion. •Knock-down of syntaxin-4 also leads to the accumulation of IgE in the cell. •Immuno-fluorescence staining shows co-localisation of IgE and syntaxin-4 in U266 cells. •Findings suggest a critical requirement for syntaxin-4 in IgE secretion from plasma cells. -- Abstract: The humoral immune system provides a crucial first defense against the invasion of microbial pathogens via the secretion of antigen specific immunoglobulins (Ig). The secretion of Ig is carried out by terminally differentiated B-lymphocytes called plasma cells. Despite the key role of plasma cells in the immune response, the mechanisms by which they constitutively traffic large volumes of Ig out of the cell is poorly understood. The involvement of Soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins in the regulation of protein trafficking from cells has been well documented. Syntaxin-4, a member of the Qa SNARE syntaxin family has been implicated in fusion events at the plasma membrane in a number of cells in the immune system. In this work we show that knock-down of syntaxin-4 in the multiple myeloma U266 human plasma cell line results in a loss of IgE secretion and accumulation of IgE within the cells. Furthermore, we show that IgE co-localises with syntaxin-4 in U266 plasma cells suggesting direct involvement in secretion at the plasma membrane. This study demonstrates that syntaxin-4 plays a critical role in the secretion of IgE from plasma cells and sheds some light on the mechanisms by which these cells constitutively traffic vesicles to the surface for secretion. An understanding of this machinery may be beneficial in identifying potential therapeutic targets in multiple myeloma and autoimmune disease where over-production of Ig leads to severe pathology in patients.

Syntaxin-4 is essential for IgE secretion by plasma cells

International Nuclear Information System (INIS)

Rahman, Arman; DeCourcey, Joseph; Larbi, Nadia Ben; Loughran, Sinéad T.; Walls, Dermot; Loscher, Christine E.

2013-01-01

Highlights: •Knock-down of syntaxin-4 in U266 plasma cells resulted in reduction of IgE secretion. •Knock-down of syntaxin-4 also leads to the accumulation of IgE in the cell. •Immuno-fluorescence staining shows co-localisation of IgE and syntaxin-4 in U266 cells. •Findings suggest a critical requirement for syntaxin-4 in IgE secretion from plasma cells. -- Abstract: The humoral immune system provides a crucial first defense against the invasion of microbial pathogens via the secretion of antigen specific immunoglobulins (Ig). The secretion of Ig is carried out by terminally differentiated B-lymphocytes called plasma cells. Despite the key role of plasma cells in the immune response, the mechanisms by which they constitutively traffic large volumes of Ig out of the cell is poorly understood. The involvement of Soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins in the regulation of protein trafficking from cells has been well documented. Syntaxin-4, a member of the Qa SNARE syntaxin family has been implicated in fusion events at the plasma membrane in a number of cells in the immune system. In this work we show that knock-down of syntaxin-4 in the multiple myeloma U266 human plasma cell line results in a loss of IgE secretion and accumulation of IgE within the cells. Furthermore, we show that IgE co-localises with syntaxin-4 in U266 plasma cells suggesting direct involvement in secretion at the plasma membrane. This study demonstrates that syntaxin-4 plays a critical role in the secretion of IgE from plasma cells and sheds some light on the mechanisms by which these cells constitutively traffic vesicles to the surface for secretion. An understanding of this machinery may be beneficial in identifying potential therapeutic targets in multiple myeloma and autoimmune disease where over-production of Ig leads to severe pathology in patients

Variability in P-Glycoprotein Inhibitory Potency (IC50) Using Various in Vitro Experimental Systems: Implications for Universal Digoxin Drug- Drug Interaction Risk Assessment Decision Criterias

NARCIS (Netherlands)

Bentz, J.; O'Connor, M.P.; Bednarczyk, D.; Coleman, J.; Lee, C.; Palm, J.; Pak, Y.A.; Perloff, E.S.; Reyner, E.; Balimane, P.; Brännström, M.; Chu, X.; Funk, C.; Guo, A.; Hanna, I.; Herédi-Szabó, K.; Hillgren, K.; Li, L.; Hollnack-Pusch, E.; Jamei, M.; Lin, X.; Mason, A.K.; Neuhoff, S.; Patel, A.; Podila, L.; Plise, E.; Rajaraman, G.; Salphati, L.; Sands, E.; Taub, M.E.; Taur, J.-S.; Weitz, D.; Wortelboer, H.M.; Xia, C.Q.; Xiao, G.; Yabut, J.; Yamagata, T.; Zhang, L.; Ellens, H.

2013-01-01

A P-glycoprotein (P-gp) IC50 working group was established with 23 participating pharmaceutical and contract research laboratories and one academic institution to assess interlaboratory variability in P-gp IC 50 determinations. Each laboratory followed its in-house protocol to determine in vitro

Effects of prostaglandin E/sub 1/ on the metabolism in rat parathyroid gland in vitro

Energy Technology Data Exchange (ETDEWEB)

Licata, A A [Rochester Univ., NY (USA). School of Medicine and Dentistry; Au, W Y [Arkansas Univ., Little Rock (USA); Vera, J; Bartter, F C [National Institutes of Health, Bethesda, MD (USA)

1979-01-04

Some effects of prostaglandin E/sub 1/ on the metabolism of rat parathyroid glands have been investigated using a culture system containing basal Eagle's medium supplemented with 5-10% heat-inactivated rat serum. Rat parathyroid glands incorporate (/sup 3/H)fucose and /sup 14/C-labeled amino acids into cellular glycoproteins and secrete some of these into the culture medium. Gel filtration chromatography separates these glycoproteins into three classes, the smallest of which (peak 3) is secreted with immunoreactive parathyroid hormone. In cultures of 48 h, prostaglandin E/sub 1/ (1 ..mu..g/ml) specifically inhibits the secretion of peak 3 and of parathyroid hormone but has no effect on the incorporation of (/sup 3/H)-fucose, /sup 14/C-labeled amino acids, or (/sup 3/H)uridine into parathyroid glands. Cytochalasin B inhibits the secretion of parathyroid hormone and the incorporation of isotopic fucose and amino acids. Cortisol stimulates incorporation of (/sup 3/H)fucose and the secretion of parathyroid hormone even in the presence of inhibitory doses of prostaglandin E/sub 1/. It is concluded that, in organ culture, prostaglandin E/sub 1/ inhibits the secretion of parathyroid hormone and of a specific glycoprotein the function of which may be related to the secretion of the hormone.

Ghrelin secretion in humans - a role for the vagus nerve?

DEFF Research Database (Denmark)

Veedfald, S; Plamboeck, A; Hartmann, B

2018-01-01

BACKGROUND: Ghrelin, an orexigenic peptide, is secreted from endocrine cells in the gastric mucosa. Circulating levels rise in the preprandial phase, suggesting an anticipatory or cephalic phase of release, and decline in the postprandial phase, suggesting either the loss of a stimulatory factor...... or inhibition by factors released when nutrients enter the intestine. We hypothesized that vagal signals are not required for the (i) preprandial increase or (ii) postprandial suppression of ghrelin levels. Further, we wanted to investigate the hypothesis that (iii) glucagon-like peptide-1 might be implicated...... in the postprandial decline in ghrelin levels. METHODS: We measured ghrelin levels in plasma from sham-feeding and meal studies carried out in vagotomized individuals and controls, and from a GLP-1 infusion study carried out in fasting healthy young individuals. KEY RESULTS: We find that (i) ghrelin secretion...

Cholecystokinin inhibits gastrin secretion independently of paracrine somatostatin secretion in the pig

DEFF Research Database (Denmark)

Schmidt, P T; Hansen, L; Hilsted, L

2004-01-01

BACKGROUND: Cholecystokinin inhibits the secretion of gastrin from antral G cells, an effect that is speculated to be mediated by D cells secreting somatostatin. The aim of the study was to test directly whether cholecystokinin inhibition of antral gastrin secretion is mediated by somatostatin....... METHODS: The effects of CCK on gastrin and somatostatin secretion were studied in isolated vascularly perfused preparations of pig antrum before and after immunoneutralization brought about by infusion of large amounts of a high affinity monoclonal antibody against somatostatin. RESULTS: CCK infusion...... at 10(-9) M and 10(-8) M decreased gastrin output to 70.5% +/- 7.6% (n = 8) and 76.3% +/- 3.6% (n = 7) of basal output, respectively. CCK at 10(-10) M had no effect (n = 6). Somatostatin secretion was dose-dependently increased by CCK infusion and increased to 268 +/- 38.2% (n = 7) of basal secretion...

Decidual-secreted factors alter invasive trophoblast membrane and secreted proteins implying a role for decidual cell regulation of placentation.

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Ellen Melaleuca Menkhorst

Full Text Available Inadequate or inappropriate implantation and placentation during the establishment of human pregnancy is thought to lead to first trimester miscarriage, placental insufficiency and other obstetric complications. To create the placental blood supply, specialized cells, the 'extravillous trophoblast' (EVT invade through the differentiated uterine endometrium (the decidua to engraft and remodel uterine spiral arteries. We hypothesized that decidual factors would regulate EVT function by altering the production of EVT membrane and secreted factors. We used a proteomics approach to identify EVT membrane and secreted proteins regulated by decidual cell factors. Human endometrial stromal cells were decidualized in vitro by treatment with estradiol (10(-8 M, medroxyprogesterone acetate (10(-7 M and cAMP (0.5 mM for 14 days. Conditioned media (CM was collected on day 2 (non-decidualized CM and 14 (decidualized CM of treatment. Isolated primary EVT cultured on Matrigel™ were treated with media control, non-decidualized or decidualized CM for 16 h. EVT CM was fractionated for proteins <30 kDa using size-exclusion affinity nanoparticles (SEAN before trypsin digestion and HPLC-MS/MS. 43 proteins produced by EVT were identified; 14 not previously known to be expressed in the placenta and 12 which had previously been associated with diseases of pregnancy including preeclampsia. Profilin 1, lysosome associated membrane glycoprotein 1 (LAMP1, dipeptidyl peptidase 1 (DPP1/cathepsin C and annexin A2 expression by interstitial EVT in vivo was validated by immunhistochemistry. Decidual CM regulation in vitro was validated by western blotting: decidualized CM upregulated profilin 1 in EVT CM and non-decidualized CM upregulated annexin A2 in EVT CM and pro-DPP1 in EVT cell lysate. Here, non-decidualized factors induced protease expression by EVT suggesting that non-decidualized factors may induce a pro-inflammatory cascade. Preeclampsia is a pro

Dynamic quantum secret sharing

International Nuclear Information System (INIS)

Jia, Heng-Yue; Wen, Qiao-Yan; Gao, Fei; Qin, Su-Juan; Guo, Fen-Zhuo

2012-01-01

In this Letter we consider quantum secret sharing (QSS) between a sender and a dynamic agent group, called dynamic quantum secret sharing (DQSS). In the DQSS, the change of the agent group is allowable during the procedure of sharing classical and quantum information. Two DQSS schemes are proposed based on a special kind of entangled state, starlike cluster states. Without redistributing all the shares, the changed agent group can reconstruct the sender's secret by their cooperation. Compared with the previous quantum secret sharing scheme, our schemes are more flexible and suitable for practical applications. -- Highlights: ► We consider quantum secret sharing between a sender and a dynamic agent group, called dynamic quantum secret sharing (DQSS). ► In the DQSS, the change of the agent group is allowable during the procedure of sharing classical and quantum information. ► Two DQSS schemes are proposed based on a special kind of entangled state, starlike cluster states. ► Without redistributing all the shares, the changed agent group can reconstruct the sender's secret by their cooperation. ► Compared with the previous quantum secret sharing scheme, our schemes are more flexible and suitable for practical applications.

Rhodocytin (aggretin) activates platelets lacking alpha(2)beta(1) integrin, glycoprotein VI, and the ligand-binding domain of glycoprotein Ibalpha

DEFF Research Database (Denmark)

Bergmeier, W; Bouvard, D; Eble, J A

2001-01-01

Although alpha(2)beta(1) integrin (glycoprotein Ia/IIa) has been established as a platelet collagen receptor, its role in collagen-induced platelet activation has been controversial. Recently, it has been demonstrated that rhodocytin (also termed aggretin), a snake venom toxin purified from the v...

Comparison of glycoprotein expression between ovarian and colon adenocarcinomas

DEFF Research Database (Denmark)

Multhaupt, H A; Arenas-Elliott, C P; Warhol, M J

1999-01-01

, carcinoembryonic antigen, and cytokeratins 7 and 20 to detect tumor-associated glycoproteins and keratin proteins in ovarian and colonic carcinomas. RESULTS: CA125, carcinoembryonic antigen, and cytokeratins 7 and 20 can distinguish between colonic and serous or endometrioid adenocarcinomas of the ovary in both...... primary and metastatic lesions. Mucinous ovarian adenocarcinomas differed in that they express carcinoembryonic antigen and cytokeratins 7 and 20 and weakly express CA125. The other glycoprotein antigens were equally expressed by ovarian and colonic adenocarcinomas and therefore were of no use...... in distinguishing between these 2 entities. CONCLUSION: A panel of monoclonal antibodies against cytokeratins 7 and 20 antigens, CA125, and carcinoembryonic antigen is useful in differentiating serous and endometrioid adenocarcinomas of the ovary from colonic adenocarcinomas. Mucinous ovarian adenocarcinomas cannot...

IgA antibodies against β2 glycoprotein I in hemodialysis patients are an independent risk factor for mortality.

Science.gov (United States)

Serrano, Antonio; García, Florencio; Serrano, Manuel; Ramírez, Elisa; Alfaro, F Javier; Lora, David; de la Cámara, Agustín Gómez; Paz-Artal, Estela; Praga, Manuel; Morales, Jose M

2012-06-01

Cardiovascular complications are the most important cause of death in patients on dialysis with end-stage renal disease. Antibodies reacting with β-glycoprotein I seem to play a pathogenic role in antiphospholipid syndrome and stroke and are involved in the origin of atherosclerosis. Here we evaluated the presence of anticardiolipin and anti-β-glycoprotein I antibodies together with other vascular risk factors and their relationship with mortality and cardiovascular morbidity in a cohort of 124 hemodialysis patients prospectively followed for 2 years. Of these, 41 patients were significantly positive for IgA anti-β-glycoprotein I, and the remaining had normal values. At 24 months, overall and cardiovascular mortality and thrombotic events were all significantly higher in patients with high anti-β-glycoprotein I antibodies. Multivariate analysis using Cox regression modeling found that age, hypoalbuminemia, use of dialysis catheters, and IgA β-glycoprotein I antibodies were independent risk factors for death. Thus, IgA antibodies to β-glycoprotein I are detrimental to the clinical outcome of hemodialysis patients.

Glycoprotein Ibalpha signalling in platelet apoptosis and clearance

NARCIS (Netherlands)

van der Wal, E.

2010-01-01

Storage of platelets at low temperature reduces bacterial growth and might better preserve the haemostatic function of platelets than current procedures. Incubation at 0C is known to expose ?-N-acetyl-D-glucosamine-residues on glycoprotein (GP)Ibalpha inducing receptor-clustering and platelet

Serum-SP/sub 1/-pregnancy-specific-. beta. -glycoprotein in choriocarcinoma and other neoplastic disease

Energy Technology Data Exchange (ETDEWEB)

Searle, F; Leake, B A; Bagshawe, K D; Dent, J [Charing Cross Group of Hospitals, London (UK)

1978-03-18

A radioimmunoassay for a placental glycoprotein, ..beta../sub 1/SP/sub 1/, capable of detecting 2 ..mu..g/l of the glycoprotein in serum was used to measure concentrations of ..beta../sub 1/SP/sub 1/ in patients with choriocarcinoma, teratoma, colonic cancer, breast cancer, and ovarian cancer. Twelve out of 94 (13%) healthy men and healthy non-pregnant women had detectable serum-..beta../sub 1/SP/sub 1/ concentrations. Concentrations up to 50,000 ..mu..g/l were found in the sera of patients with hydatidiform mole, invasive mole, choriocarcinoma, and malignant teratoma. ..beta../sub 1/-glycoprotein concentrations were generally much lower than corresponding concentrations of chorionic gonadotrophin which is the most reliable marker for trophoblastic tumors. In a few cases, however, ..beta../sub 1/-glycoprotein measurements may be useful in the detection of minimal residual tumor. The slightly raised values found in some patients with carcinoma of the colon, breast, or ovary seem unlikely to be useful for diagnostic purposes or for monitoring the course of these cancers.

A role for SPARC in the moderation of human insulin secretion.

Directory of Open Access Journals (Sweden)

Lorna W Harries

Full Text Available AIMS/HYPOTHESIS: We have previously shown the implication of the multifunctional protein SPARC (Secreted protein acidic and rich in cysteine/osteonectin in insulin resistance but potential effects on beta-cell function have not been assessed. We therefore aimed to characterise the effect of SPARC on beta-cell function and features of diabetes. METHODS: We measured SPARC expression by qRT-PCR in human primary pancreatic islets, adipose tissue, liver and muscle. We then examined the relation of SPARC with glucose stimulated insulin secretion (GSIS in primary human islets and the effect of SPARC overexpression on GSIS in beta cell lines. RESULTS: SPARC was expressed at measurable levels in human islets, adipose tissue, liver and skeletal muscle, and demonstrated reduced expression in primary islets from subjects with diabetes compared with controls (p< = 0.05. SPARC levels were positively correlated with GSIS in islets from control donors (p< = 0.01. Overexpression of SPARC in cultured beta-cells resulted in a 2.4-fold increase in insulin secretion in high glucose conditions (p< = 0.01. CONCLUSIONS: Our data suggest that levels of SPARC are reduced in islets from donors with diabetes and that it has a role in insulin secretion, an effect which appears independent of SPARC's modulation of obesity-induced insulin resistance in adipose tissue.

Rat macrophages: membrane glycoproteins in differentiation and function

NARCIS (Netherlands)

van den Berg, T. K.; Döpp, E. A.; Dijkstra, C. D.

2001-01-01

Macrophages (mphi) play a crucial role in the immune system. The rat offers unique advantages for studying the biology of mphi. Firstly, monoclonal antibodies (mAb) against many rat mphi surface glycoproteins have become available. These have not only demonstrated a considerable heterogeneity among

Electrophoretic demonstration of glycoproteins, lipoproteins, and phosphoproteins in human and bovine enamel

DEFF Research Database (Denmark)

Kirkeby, S; Moe, D; Bøg-Hansen, T C

1990-01-01

Enamel proteins from fully mineralized human molars and from bovine tooth germs were separated by electrophoresis. The gels were stained for detection of glycoproteins, lipoproteins, and phosphoproteins. Glycoproteins were shown by periodic acid-Schiff staining and lectin blotting. In mature human...... enamel a number of high molecular weight proteins could be demonstrated after ethylenediaminetetra-acetic acid demineralization and subsequent Triton X-100 extraction. These proteins are suggested to be lipoproteins. Phosphoproteins could only be visualized in enamel matrix from the tooth germs....

A Critical View on In Vitro Analysis of P-glycoprotein (P-gp) Transport Kinetics

DEFF Research Database (Denmark)

Saaby, Lasse; Brodin, Birger

2017-01-01

Transport proteins expressed in the different barriers of the human body can have great implications on absorption, distribution, and excretion of drug compounds. Inhibition or saturation of a transporter can potentially alter these absorbtion, distribution, metabolism and elimination properties...... and thereby also the pharmacokinetic profile and bioavailability of drug compounds. P-glycoprotein (P-gp, ABCB1) is an efflux transporter which is present in most of the barriers of the body, including the small intestine, the blood-brain barrier, the liver, and the kidney. In all these tissues, P-gp may...... mediate efflux of drug compounds and may also be a potential site for drug-drug interactions. Consequently, there is a need to be able to predict the saturation and inhibition of P-gp and other transporters in vivo. For this purpose, Michaelis-Menten steady-state analysis has been applied to estimate...

Early expression of pregnancy-specific glycoprotein 22 (PSG22) by trophoblast cells modulates angiogenesis in mice.

Science.gov (United States)

Blois, Sandra M; Tirado-González, Irene; Wu, Julie; Barrientos, Gabriela; Johnson, Briana; Warren, James; Freitag, Nancy; Klapp, Burghard F; Irmak, Ster; Ergun, Suleyman; Dveskler, Gabriela S

2012-06-01

Mouse and human pregnancy-specific glycoproteins (PSG) are known to exert immunomodulatory functions during pregnancy by inducing maternal leukocytes to secrete anti-inflammatory cytokines that promote a tolerogenic decidual microenvironment. Many such anti-inflammatory mediators also function as proangiogenic factors, which, along with the reported association of murine PSG with the uterine vasculature, suggest that PSG may contribute to the vascular adaptations necessary for successful implantation and placental development. We observed that PSG22 is strongly expressed around the embryonic crypt on Gestation Day 5.5, indicating that trophoblast giant cells are the main source of PSG22 during the early stages of pregnancy. PSG22 treatment up-regulated the secretion of transforming growth factor beta 1 and vascular endothelial growth factor A (VEGFA) in murine macrophages, uterine dendritic cells, and natural killer cells. A possible role of PSGs in uteroplacental angiogenesis is further supported by the finding that incubation of endothelial cells with PSG22 resulted in the formation of tubes in the presence and absence of VEGFA. We determined that PSG22, like human PSG1 and murine PSG17 and PSG23, binds to the heparan sulfate chains in syndecans. Therefore, our findings indicate that despite the independent evolution and expansion of human and rodent PSG, members in both families have conserved functions that include their ability to induce anti-inflammatory cytokines and proangiogenic factors as well as to induce the formation of capillary structures by endothelial cells. In summary, our results indicate that PSG22, the most abundant PSG expressed during mouse early pregnancy, is likely a major contributor to the establishment of a successful pregnancy.

Effect of expression of P-glycoprotein on technetium-99m methoxyisobutylisonitrile single photon emission computed tomography of brain tumors

Energy Technology Data Exchange (ETDEWEB)

Shibata, Yasushi; Matsumura, Akira; Nose, Tadao [Tsukuba Univ., Ibaraki (Japan). Inst. of Clinical Medicine

2002-08-01

The expression of P-glycoprotein was investigated imunohistochemically in 26 brain tumor tissues and compared with the findings of technetium-99m methoxyisobutylisonitrile single photon emission computed tomography ({sup 99m}Tc-MIBI SPECT) to clarify the effect of P-glycoprotein on the diagnostic accuracy. P-glycoprotein labeling index of both tumor cells and vascular endothelial cells showed no clear relationship with the findings of {sup 99m}Tc-MIBI SPECT imaging. Expression of P-glycoprotein has no effect on the diagnostic accuracy of {sup 99m}Tc-MIBI SPECT. (author)

Changes in intestinal absorption of nutrients and brush border glycoproteins after total parenteral nutrition in rats.

Science.gov (United States)

Miura, S; Tanaka, S; Yoshioka, M; Serizawa, H; Tashiro, H; Shiozaki, H; Imaeda, H; Tsuchiya, M

1992-01-01

The effect of total parenteral nutrition on nutrients absorption and glycoprotein changes of brush border membrane was examined in rat small intestine. In total parenteral nutrition rats, a marked decrease in activity of brush border enzymes was observed mainly in the proximal and middle segments of the intestine. Galactose perfusion of jejunal segment showed that hexose absorption was significantly inhibited, while intestinal absorption of glycine or dipeptide, glycylglycine was not significantly affected by total parenteral nutrition treatment. When brush border membrane glycoprotein profile was examined by [3H]-glucosamine or [3H]-fucose incorporation into jejunal loops, significant changes were observed in the glycoprotein pattern of brush border membrane especially in the high molecular weight range over 120 kDa after total parenteral nutrition treatment, suggesting strong dependency of glycoprotein synthesis on luminal substances. Molecular weight of sucrase isomaltase in brush border membrane detected by specific antibody showed no significant difference, however, in total parenteral nutrition and control rats. Also, molecular weight of specific sodium glucose cotransporter of intestinal brush border membrane detected by selective photoaffinity labelling was not altered in total parenteral nutrition rats. It may be that prolonged absence of oral food intake may produce significant biochemical changes in brush border membrane glycoprotein and absorptive capacity of small intestine, but these changes were not observed in all brush border membrane glycoproteins. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:1582592

Carcinoma-specific Ulex europaeus agglutinin-I binding glycoproteins of human colorectal carcinoma and its relation to carcinoembryonic antigen.

Science.gov (United States)

Matsushita, Y; Yonezawa, S; Nakamura, T; Shimizu, S; Ozawa, M; Muramatsu, T; Sato, E

1985-08-01

Glycoproteins binding to Ulex europaeus agglutinin-I (UEA-I) lectin, which recognizes the terminal alpha-L-fucose residue, were analyzed in 18 cases of human colorectal carcinoma by sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by the Western blotting method. In the distal large bowel (descending and sigmoid colon and rectum), high-molecular-weight glycoproteins binding to UEA-I existed in carcinoma tissue but not in normal mucosa. In the proximal large bowel (ascending and transverse colon), high-molecular-weight glycoproteins binding to UEA-I were found both in normal mucosa and in carcinoma tissue, whereas those from the carcinoma tissue had an apparently lower molecular weight as compared to the weight of those from the normal mucosa. Thus there is a biochemical difference in UEA-I binding glycoproteins between the normal mucosa and the carcinoma tissue, although in our previous histochemical study no difference was observed in UEA-I binding glycoproteins of the proximal large bowel between the carcinoma tissue and the normal mucosa. Furthermore, carcinoembryonic antigen from the carcinoma tissue was found to have the same electrophoretical mobility as the UEA-I binding glycoproteins.

Extra-oviductal expression of oviductal glycoprotein 1 in mouse ...

Indian Academy of Sciences (India)

2017-01-11

Jan 11, 2017 ... oestrogen-dependent protein, oviduct-specific glycoprotein. 1 (Ovgp1) also ... the tissues collected were testis, epididymis, prostate gland and seminal vesicle. ... The antigenic sites were unmasked by incuba- tion of sections ...

Celastraceae sesquiterpenes as a new class of modulators that bind specifically to human P-glycoprotein and reverse cellular multidrug resistance.

Science.gov (United States)

Muñoz-Martínez, Francisco; Lu, Peihua; Cortés-Selva, Fernando; Pérez-Victoria, José María; Jiménez, Ignacio A; Ravelo, Angel G; Sharom, Frances J; Gamarro, Francisco; Castanys, Santiago

2004-10-01

Overexpression of ABCB1 (MDR1) P-glycoprotein, a multidrug efflux pump, is one mechanism by which tumor cells may develop multidrug resistance (MDR), preventing the successful chemotherapeutic treatment of cancer. Sesquiterpenes from Celastraceae family are natural compounds shown previously to reverse MDR in several human cancer cell lines and Leishmania strains. However, their molecular mechanism of reversion has not been characterized. In the present work, we have studied the ability of 28 dihydro-beta-agarofuran sesquiterpenes to reverse the P-glycoprotein-dependent MDR phenotype and elucidated their molecular mechanism of action. Cytotoxicity assays using human MDR1-transfected NIH-3T3 cells allowed us to select the most potent sesquiterpenes reversing the in vitro resistance to daunomycin and vinblastine. Flow cytometry experiments showed that the above active compounds specifically inhibited drug transport activity of P-glycoprotein in a saturable, concentration-dependent manner (K(i) down to 0.24 +/- 0.01 micromol/L) but not that of ABCC1 (multidrug resistance protein 1; MRP1), ABCC2 (MRP2), and ABCG2 (breast cancer resistance protein; BCRP) transporters. Moreover, sesquiterpenes inhibited at submicromolar concentrations the P-glycoprotein-mediated transport of [(3)H]colchicine and tetramethylrosamine in plasma membrane from CH(R)B30 cells and P-glycoprotein-enriched proteoliposomes, supporting that P-glycoprotein is their molecular target. Photoaffinity labeling in plasma membrane and fluorescence spectroscopy experiments with purified protein suggested that sesquiterpenes interact with transmembrane domains of P-glycoprotein. Finally, sesquiterpenes modulated P-glycoprotein ATPase-activity in a biphasic, concentration-dependent manner: they stimulated at very low concentrations but inhibited ATPase activity as noncompetitive inhibitors at higher concentrations. Sesquiterpenes from Celastraceae are promising P-glycoprotein modulators with potential

Glycoprotein H of herpes simplex virus type 1 requires glycoprotein L for transport to the surfaces of insect cells

NARCIS (Netherlands)

Westra, DF; Glazenburg, KL; Harmsen, MC; Tiran, A; Scheffer, AJ; Welling, GW; The, TH; WellingWester, S

In mammalian cells, formation of heterooligomers consisting of the glycoproteins H and L (gH and gL) of herpes simplex virus type 1 is essential for the cell-to-cell spread of virions and for the penetration of virions into cells. We examined whether formation of gH1/gL1 heterooligomers and cell

MDR1 P-glycoprotein transports endogenous opioid peptides

NARCIS (Netherlands)

Oude Elferink, R. P.; Zadina, J.

2001-01-01

MDR1 P-glycoprotein is generally regarded as an efflux pump for amphipathic toxic compounds. The question remains, however, whether certain endogenous compounds are also substrates for this transporter. Certain peptides have been shown to interact with MDR1 Pgp as well and we have therefore

Expression of variable viruses as herpes simplex glycoprotein D and varicella zoster gE glycoprotein using a novel plasmid based expression system in insect cell

Directory of Open Access Journals (Sweden)

A.M. Al-Sulaiman

2017-11-01

Full Text Available Several prokaryotic and eukaryotic expression systems have been used for in vitro production of viruses’ proteins. However eukaryotic expression system was always the first choice for production of proteins that undergo post-translational modification such as glycosylation. Recombinant baculoviruses have been widely used as safe vectors to express heterologous genes in the culture of insect cells, but the manipulation involved in creating, titrating, and amplifying viral stocks make it time consuming and laborious. Therefore, to facilitate rapid expression in insect cell, a plasmid based expression system was used to express herpes simplex type 1 glycoprotein D (HSV-1 gD and varicella zoster glycoprotein E (VZV gE. Recombinant plasmids were generated, transfected into insect cells (SF9, and both glycoproteins were expressed 48 h post-infection. A protein with approximately molecular weight of 64-kDa and 98-kDa for HSV-1 gD and VZV gE respectively was expressed and confirmed by SDS. Proteins were detected in insect cells cytoplasm and outer membrane by immunofluorescence. The antigenicity and immunoreactivity of each protein were confirmed by immunoblot and ELISA. Results suggest that this system can be an alternative to the traditional baculovirus expression for small scale expression system in insect cells.

Quantum strongly secure ramp secret sharing

DEFF Research Database (Denmark)

Zhang, Paul; Matsumoto, Rytaro Yamashita

2015-01-01

Quantum secret sharing is a scheme for encoding a quantum state (the secret) into multiple shares and distributing them among several participants. If a sufficient number of shares are put together, then the secret can be fully reconstructed. If an insufficient number of shares are put together...... however, no information about the secret can be revealed. In quantum ramp secret sharing, partial information about the secret is allowed to leak to a set of participants, called an unqualified set, that cannot fully reconstruct the secret. By allowing this, the size of a share can be drastically reduced....... This paper introduces a quantum analog of classical strong security in ramp secret sharing schemes. While the ramp secret sharing scheme still leaks partial information about the secret to unqualified sets of participants, the strong security condition ensures that qudits with critical information can...

Impact of alg3 gene deletion on growth, development, pigment production, protein secretion, and functions of recombinant Trichoderma reesei cellobiohydrolases in Aspergillus niger

Energy Technology Data Exchange (ETDEWEB)

Dai, Ziyu; Aryal, Uma K.; Shukla, Anil; Qian, Wei-Jun; Smith, Richard D.; Magnuson, Jon K.; Adney, William S.; Beckham, Gregg T.; Brunecky, Roman; Himmel, Michael E.; Decker, Stephen R.; Ju, Xiaohui; Zhang, Xiao; Baker, Scott E.

2013-12-01

ALG3 is a Family 58 glycosyltransferase enzyme involved in early N-linked glycan synthesis. Here, we investigated the effect of the alg3 gene disruption on growth, development, metabolism, and protein secretion in Aspergillus niger. The alg3 gene deletion resulted in a significant reduction of growth on complete (CM) and potato dextrose agar (PDA) media and a substantial reduction of spore production on CM. It also delayed spore germination in the liquid cultures of both CM and PDA media, but led to a significant accumulation of red pigment on both CM and liquid modified minimal medium (MM) supplemented with yeast extract. The relative abundance of 55 proteins of the total 190 proteins identified in the secretome was significantly different as a result of alg3 gene deletion. Comparison of a Trichoderma reesei cellobiohydrolase (Cel7A) heterologously expressed in A. niger parental and Δalg3 strains showed that the recombinant Cel7A expressed in the mutant background was smaller in size than that from the parental strains. This study suggests that ALG3 is critical for growth and development, pigment production, and protein secretion in A. niger. Functional analysis of recombinant Cel7A with aberrant glycosylation demonstrates the feasibility of this alternative approach to evaluate the role of N-linked glycosylation in glycoprotein secretion and function.

Low rate doses effects of gamma radiation on glycoproteins of transmembrane junctions in fibroblasts

International Nuclear Information System (INIS)

Bringas, J.E.; Caceres, J.L.

1996-01-01

Glycoproteins of trans-membrane junctions are molecules that help to bind cells with the extracellular matrix. Integrins are the most important trans-membrane molecules among others. The damage of gamma radiation on those proteins could be an important early event that causes membrane abnormalities which may lead to cell malfunction and cancer induced by radiation due to cell dissociation. Randomized blocks with 3 repetitions of mouse embryo fibroblast cultures, were irradiated with Cobalt-60 gamma rays, during 20 days. Biological damage to glycoproteins and integrins was evaluated by cellular growth and fibroblast proliferative capacity. Integrins damage was studied by isolation by column immunoaffinity chromatography migrated on SDS-Page under reducing and non reducing conditions, and inhibition of integrins extracellular matrix adhesion by monoclonal antibodies effect. The dose/rate (0.05 Gy/day-0.2 Gy/day) of gamma given to cells did not show damage evidence on glycoproteins and integrins. If damage happened, it was repaired by cells very soon, was delayed by continuous cellular division or by glycoproteins characteristic of being multiple extracellular ligatures. Bio effects became more evident with an irradiation time greater than 20 days or a high dose/rate. (authors). 6 refs

Dynamic secrets in communication security

CERN Document Server

Xiao, Sheng; Towsley, Donald

2013-01-01

Dynamic secrets are constantly generated and updated from messages exchanged between two communication users. When dynamic secrets are used as a complement to existing secure communication systems, a stolen key or password can be quickly and automatically reverted to its secret status without disrupting communication. 'Dynamic Secrets in Communication Security' presents unique security properties and application studies for this technology. Password theft and key theft no longer pose serious security threats when parties frequently use dynamic secrets. This book also illustrates that a dynamic

A review on the relation between the brain-serum concentration ratio of drugs and the influence of P-glycoprotein

DEFF Research Database (Denmark)

Ejsing, Thomas Broeng; Morling, Niels; Linnet, Kristian

2007-01-01

This overview on the brain-serum relationship for drugs illustrates the importance of the drug transporter P-glycoprotein at the blood-brain barrier. Generally, an inverse relationship exists between the magnitude of the brain-serum ratio and the influence of P-glycoprotein. Concerning the pharma...... the pharmacogenomics of P-glycoprotein, no clear effect of single nucleotide polymorphisms (SNPs) has been demonstrated in humans....

Developmental and functional significance of the CSF-1 proteoglycan chondroitin sulfate chain

OpenAIRE

Nandi, Sayan; Akhter, Mohammed P.; Seifert, Mark F.; Dai, Xu-Ming; Stanley, E. Richard

2006-01-01

The primary macrophage growth factor, colony-stimulating factor-1 (CSF-1), is homodimeric and exists in 3 biologically active isoforms: a membrane-spanning, cell-surface glycoprotein (csCSF-1) and secreted glycoprotein (sgCSF-1) and proteoglycan (spCSF-1) isoforms. To investigate the in vivo role of the chondroitin sulfate glycosaminoglycan (GAG) chain of spCSF-1, we created mice that exclusively express, in a normal tissue-specific and developmental manner, either the secreted precursor of s...

A hybrid monolithic column based on boronate-functionalized graphene oxide nanosheets for online specific enrichment of glycoproteins.

Science.gov (United States)

Zhou, Chanyuan; Chen, Xiaoman; Du, Zhuo; Li, Gongke; Xiao, Xiaohua; Cai, Zongwei

2017-05-19

A hybrid monolithic column based on aminophenylboronic acid (APBA)-functionalized graphene oxide (GO) has been developed and used for selective enrichment of glycoproteins. The APBA/GO composites were homogeneously incorporated into a polymer monolithic column with the help of oligomer matrix and followed by in situ polymerization. The effect of dispersion of APBA/GO composites in the polymerization mixture on the performance of the monolithic column was explored in detail. The presence of graphene oxide not only enlarged the BET surface area from 6.3m 2 /g to 169.4m 2 /g, but also provided abundant boronic acid moieties for glycoprotein extraction, which improved the enrichment selectivity and efficiency for glycoproteins. The APBA/GO hybrid monolithic column was incorporated into a sequential injection system, which facilitated online extraction of proteins. Combining the superior properties of extraordinary surface area of GO and the affinity interaction of APBA to glycoproteins, the APBA/GO hybrid monolithic column showed higher enrichment factors for glycoproteins than other proteins without cis-diol-containing groups. Also, under comparable or even shorter processing time and without the addition of any organic solvent, it showed higher binding capacity toward glycoproteins compared with the conventional boronate affinity monolithic column. The practical applicability of this system was demonstrated by processing of egg white samples for extraction of ovalbumin and ovotransferrin, and satisfactory results were obtained by assay with SDS-PAGE. Copyright © 2017 Elsevier B.V. All rights reserved.

Mining secreted proteins that function in pepper fruit development and ripening using a yeast secretion trap (YST)

Energy Technology Data Exchange (ETDEWEB)

Lee, Je Min, E-mail: jemin@knu.ac.kr [Department of Plant Science, College of Agriculture and Life Sciences, Seoul National University, Seoul (Korea, Republic of); Department of Horticultural Science, Kyungpook National University, Daegu (Korea, Republic of); Lee, Sang-Jik [Biotechnology Institute, Nongwoo Bio Co, Ltd, Yeoju (Korea, Republic of); Department of Plant Biology, Cornell University, Ithaca, NY (United States); Rose, Jocelyn K.C. [Department of Plant Biology, Cornell University, Ithaca, NY (United States); Yeam, Inhwa [Department of Horticulture and Breeding, Andong National University, Andong (Korea, Republic of); Kim, Byung-Dong [Department of Plant Science, College of Agriculture and Life Sciences, Seoul National University, Seoul (Korea, Republic of)

2014-04-18

Highlights: • Yeast secretion trap (YST) is a valuable tool for mining secretome. • A total of 80 secreted proteins are newly identified via YST in pepper fruits. • The secreted proteins are differentially regulated during pepper development and ripening. • Transient GFP-fusion assay and in planta secretion trap can effectively validate the secretion of proteins. - Abstract: Plant cells secrete diverse sets of constitutively- and conditionally-expressed proteins under various environmental and developmental states. Secreted protein populations, or secretomes have multiple functions, including defense responses, signaling, metabolic processes, and developmental regulation. To identify genes encoding secreted proteins that function in fruit development and ripening, a yeast secretion trap (YST) screen was employed using pepper (Capsicum annuum) fruit cDNAs. The YST screen revealed 80 pepper fruit-related genes (CaPFRs) encoding secreted proteins including cell wall proteins, several of which have not been previously described. Transient GFP-fusion assay and an in planta secretion trap were used to validate the secretion of proteins encoded by selected YST clones. In addition, RNA gel blot analyses provided further insights into their expression and regulation during fruit development and ripening. Integrating our data, we conclude that the YST provides a valuable functional genomics tool for the identification of substantial numbers of novel secreted plant proteins that are associated with biological processes, including fruit development and ripening.

Mining secreted proteins that function in pepper fruit development and ripening using a yeast secretion trap (YST)

International Nuclear Information System (INIS)

Lee, Je Min; Lee, Sang-Jik; Rose, Jocelyn K.C.; Yeam, Inhwa; Kim, Byung-Dong

2014-01-01

Highlights: • Yeast secretion trap (YST) is a valuable tool for mining secretome. • A total of 80 secreted proteins are newly identified via YST in pepper fruits. • The secreted proteins are differentially regulated during pepper development and ripening. • Transient GFP-fusion assay and in planta secretion trap can effectively validate the secretion of proteins. - Abstract: Plant cells secrete diverse sets of constitutively- and conditionally-expressed proteins under various environmental and developmental states. Secreted protein populations, or secretomes have multiple functions, including defense responses, signaling, metabolic processes, and developmental regulation. To identify genes encoding secreted proteins that function in fruit development and ripening, a yeast secretion trap (YST) screen was employed using pepper (Capsicum annuum) fruit cDNAs. The YST screen revealed 80 pepper fruit-related genes (CaPFRs) encoding secreted proteins including cell wall proteins, several of which have not been previously described. Transient GFP-fusion assay and an in planta secretion trap were used to validate the secretion of proteins encoded by selected YST clones. In addition, RNA gel blot analyses provided further insights into their expression and regulation during fruit development and ripening. Integrating our data, we conclude that the YST provides a valuable functional genomics tool for the identification of substantial numbers of novel secreted plant proteins that are associated with biological processes, including fruit development and ripening

Immunoglobins in mammary secretions

DEFF Research Database (Denmark)

Hurley, W L; Theil, Peter Kappel

2013-01-01

Immunoglobulins secreted in colostrum and milk by the lactating mammal are major factors providing immune protection to the newborn. Immunoglobulins in mammary secretions represent the cumulative immune response of the lactating animal to exposure to antigenic stimulation that occurs through...... the immunoglobulins found in mammary secretions in the context of their diversity of structure, origin, mechanisms of transfer, and function....

Thiolated polymers: evidence for the formation of disulphide bonds with mucus glycoproteins.

Science.gov (United States)

Leitner, Verena M; Walker, Greg F; Bernkop-Schnürch, Andreas

2003-09-01

Disulphide bonds between thiolated polymers (thiomers) and cysteine-rich subdomains of mucus glycoproteins are supposed to be responsible for the enhanced mucoadhesive properties of thiomers. This study set out to provide evidence for these covalent interactions using poly(acrylic acid)-cysteine conjugates of 2 and 450 kDa (PAA2-Cys, PAA450-Cys) displaying 402.5-776.0 micromol thiol groups per gram polymer. The effect of the disulphide bond breaker cysteine on thiomer-mucin disulphide bonds was monitored by (1) mucoadhesion studies and (2) rheological studies. Furthermore, (3) diffusion studies and (4) gel filtration studies were performed with thiomer-mucus mixtures. The addition of cysteine significantly (Ppolymer. Gel filtration studies showed that PAA2-Cys was able to form disulphide bonds with mucin glycoproteins resulting in an altered elution profile of the mucin/PAA2-Cys mixture in comparison to mucin alone or mucin/PAA2 mixture. According to these results, the study provides evidence for the formation of covalent bonds between thiomer and mucus glycoproteins.

Cytoplasmic tail domain of glycoprotein B is essential for HHV-6 infection

Energy Technology Data Exchange (ETDEWEB)

Mahmoud, Nora F. [Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe (Japan); Faculty of Pharmacy, Suez Canal University, Ismailia (Egypt); Jasirwan, Chyntia [Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe (Japan); Division of Hepatobiliary, Department of Internal Medicine, Faculty of Medicine, University of Indonesia (Indonesia); Kanemoto, Satoshi; Wakata, Aika; Wang, Bochao; Hata, Yuuki [Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe (Japan); Nagamata, Satoshi [Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe (Japan); Department of Obstetrics and Gynecology, Kobe University Graduate School of Medicine, Kobe (Japan); Kawabata, Akiko [Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe (Japan); Tang, Huamin [Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe (Japan); Department of Immunology, Nanjing Medical University, Nanjing (China); Mori, Yasuko, E-mail: ymori@med.kobe-u.ac.jp [Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe (Japan)

2016-03-15

Human herpesvirus 6 (HHV-6) glycoprotein B (gB) is an abundantly expressed viral glycoprotein required for viral entry and cell fusion, and is highly conserved among herpesviruses. The present study examined the function of HHV-6 gB cytoplasmic tail domain (CTD). A gB CTD deletion mutant was constructed which, in contrast to its revertant, could not be reconstituted. Moreover, deletion of gB cytoplasmic tail impaired the intracellular transport of gB protein to the trans-Golgi network (TGN). Taken together, these results suggest that gB CTD is critical for HHV-6 propagation and important for intracellular transportation. - Highlights: • Glycoprotein B (gB) is highly conserved among herpesviruses. • HHV-6 gB is also abundantly expressed in virions. • In the present study, we showed the function of HHV-6 gB cytoplasmic tail domain (CTD). • We found that deletion of gB CTD impairs the intracellular transport of gB protein to the trans-Golgi network (TGN), and CTD of gB is critical for HHV-6 propagation.

Cytoplasmic tail domain of glycoprotein B is essential for HHV-6 infection

International Nuclear Information System (INIS)

Mahmoud, Nora F.; Jasirwan, Chyntia; Kanemoto, Satoshi; Wakata, Aika; Wang, Bochao; Hata, Yuuki; Nagamata, Satoshi; Kawabata, Akiko; Tang, Huamin; Mori, Yasuko

2016-01-01

Human herpesvirus 6 (HHV-6) glycoprotein B (gB) is an abundantly expressed viral glycoprotein required for viral entry and cell fusion, and is highly conserved among herpesviruses. The present study examined the function of HHV-6 gB cytoplasmic tail domain (CTD). A gB CTD deletion mutant was constructed which, in contrast to its revertant, could not be reconstituted. Moreover, deletion of gB cytoplasmic tail impaired the intracellular transport of gB protein to the trans-Golgi network (TGN). Taken together, these results suggest that gB CTD is critical for HHV-6 propagation and important for intracellular transportation. - Highlights: • Glycoprotein B (gB) is highly conserved among herpesviruses. • HHV-6 gB is also abundantly expressed in virions. • In the present study, we showed the function of HHV-6 gB cytoplasmic tail domain (CTD). • We found that deletion of gB CTD impairs the intracellular transport of gB protein to the trans-Golgi network (TGN), and CTD of gB is critical for HHV-6 propagation.

Neural glycoprotein M6a is released in extracellular vesicles and modulated by chronic stressors in blood

OpenAIRE

Monteleone, Melisa C.; Billi, Silvia C.; Brocco, Marcela A.; Frasch, Alberto C.

2017-01-01

Membrane neuronal glycoprotein M6a is highly expressed in the brain and contributes to neural plasticity promoting neurite growth and spine and synapse formation. We have previously showed that chronic stressors alter hippocampal M6a mRNA levels in rodents and tree shrews. We now show that M6a glycoprotein can be detected in mouse blood. M6a is a transmembrane glycoprotein and, as such, unlikely to be free in blood. Here we demonstrate that, in blood, M6a is transported in extracellular vesic...

Glycoprotein fucosylation is increased in seminal plasma of subfertile men

Directory of Open Access Journals (Sweden)

Beata Olejnik

2015-04-01

Full Text Available Fucose, the monosaccharide frequent in N- and O-glycans, is a part of Lewis-type antigens that are known to mediate direct sperm binding to the zona pellucida. Such interaction was found to be inhibited in vitroby fucose-containing oligo- and polysaccharides, as well as neoglycoproteins. The objective of this study was to screen seminal plasma proteins of infertile/subfertile men for the content and density of fucosylated glycoepitopes, and compare them to samples of fertile normozoospermic subjects. Seminal proteins were separated in polyacrylamide gel electrophoresis and blotted onto nitrocellulose membrane and probed with fucose-specific Aleuria aurantia lectin (AAL. Twelve electrophoretic bands were selected for quantitative densitometric analysis. It was found that the content, and especially the density of fucosylated glycans, were higher in glycoproteins present in seminal plasma of subfertile men. No profound differences in fucosylation density were found among the groups of normozoospermic, oligozoospermic, asthenozoospermic, and oligoasthenozoospermic subfertile men. According to the antibody probing, AAL-reactive bands can be attributed to male reproductive tract glycoproteins, including prostate-specific antigen, prostatic acid phosphatase, glycodelin and chorionic gonadotropin. Fibronectin, α1 -acid glycoprotein, α1 -antitrypsin, immunoglobulin G and antithrombin III may also contribute to this high fucosylation. It is suggested that the abundant fucosylated glycans in the sperm environment could interfere with the sperm surface and disturb the normal course of the fertilization cascade.

Matroids and quantum-secret-sharing schemes

International Nuclear Information System (INIS)

Sarvepalli, Pradeep; Raussendorf, Robert

2010-01-01

A secret-sharing scheme is a cryptographic protocol to distribute a secret state in an encoded form among a group of players such that only authorized subsets of the players can reconstruct the secret. Classically, efficient secret-sharing schemes have been shown to be induced by matroids. Furthermore, access structures of such schemes can be characterized by an excluded minor relation. No such relations are known for quantum secret-sharing schemes. In this paper we take the first steps toward a matroidal characterization of quantum-secret-sharing schemes. In addition to providing a new perspective on quantum-secret-sharing schemes, this characterization has important benefits. While previous work has shown how to construct quantum-secret-sharing schemes for general access structures, these schemes are not claimed to be efficient. In this context the present results prove to be useful; they enable us to construct efficient quantum-secret-sharing schemes for many general access structures. More precisely, we show that an identically self-dual matroid that is representable over a finite field induces a pure-state quantum-secret-sharing scheme with information rate 1.

Extracellular secretion of recombinant proteins

Science.gov (United States)

Linger, Jeffrey G.; Darzins, Aldis

2014-07-22

Nucleic acids encoding secretion signals, expression vectors containing the nucleic acids, and host cells containing the expression vectors are disclosed. Also disclosed are polypeptides that contain the secretion signals and methods of producing polypeptides, including methods of directing the extracellular secretion of the polypeptides. Exemplary embodiments include cellulase proteins fused to secretion signals, methods to produce and isolate these polypeptides, and methods to degrade lignocellulosic biomass.

Separation and identification of carp pituitary proteins and glycoproteins

Czech Academy of Sciences Publication Activity Database

Ryšlavá, H.; Janatová, M.; Čalounová, G.; Selicharová, Irena; Barthová, J.; Barth, Tomislav

2005-01-01

Roč. 50, č. 9 (2005), 430-437 ISSN 1212-1819 R&D Projects: GA MZe(CZ) QF3028 Institutional research plan: CEZ:AV0Z4055905 Keywords : carp hormones * glycoproteins * oligosaccharide chains Subject RIV: CE - Biochemistry Impact factor: 0.254, year: 2005

Human platelet glycoprotein IX: An adhesive prototype of leucine-rich glycoproteins with flank-center-flank structures

International Nuclear Information System (INIS)

Hickey, M.J.; Williams, S.A.; Roth, G.J.

1989-01-01

The glycoprotein (GP) Ib-IX complex on the surface of human platelets functions as the von Willebrand factor receptor and mediates von Willebrand factor-dependent platelet adhesion to blood vessels. GPIX is a relatively small (M r , 17,000) protein that may provide for membrane insertion and orientation of the larger component of the complex. GPIb (M r , 165,000). Using antibody screening, the authors cloned a cDNA encoding GPIX from a human erythroleukemia cell cDNA library constructed in phage λgt11. Lacking a 5' untranslated region and start codon, the cDNA sequence includes 604 nucleotides, beginning with 495 bases at the 5' end coding for 165 amino acids, followed by a stop codon and 106 noncoding bases at the 3' end. By Northern blot analysis, the GPIX cDNA hybridizes with a single 1.0-kilobase species of platelet poly(A) + RNA. Translation of the cDNA sequence gives a predicted protein sequence beginning with a truncated putative signal sequence of 5 amino acids followed by a sequence of 17 amino acids matching that determined directly by Edman degradation of intact GPIX. GPIX contains a leucine-rich glycoprotein (LRG) sequence of 24 amino acids similar to conserved LRG sequences in GPIb and other proteins from humans, Drosophila, and yeast. The role of the flank-LRG center-flank structure in the evolution and function of the LRG proteins remains to be defined

Encoding asymmetry of the N-glycosylation motif facilitates glycoprotein evolution.

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Ryan Williams

Full Text Available Protein N-glycosylation is found in all domains of life and has a conserved role in glycoprotein folding and stability. In animals, glycoproteins transit through the Golgi where the N-glycans are trimmed and rebuilt with sequences that bind lectins, an innovation that greatly increases structural diversity and redundancy of glycoprotein-lectin interaction at the cell surface. Here we ask whether the natural tension between increasing diversity (glycan-protein interactions and site multiplicity (backup and status quo might be revealed by a phylogenic examination of glycoproteins and NXS/T(X ≠ P N-glycosylation sites. Site loss is more likely by mutation at Asn encoded by two adenosine (A-rich codons, while site gain is more probable by generating Ser or Thr downstream of an existing Asn. Thus mutations produce sites at novel positions more frequently than the reversal of recently lost sites, and therefore more paths though sequence space are made available to natural selection. An intra-species comparison of secretory and cytosolic proteins revealed a departure from equilibrium in sequences one-mutation-away from NXS/T and in (A content, indicating strong selective pressures and exploration of N-glycosylation positions during vertebrate evolution. Furthermore, secretory proteins have evolved at rates proportional to N-glycosylation site number, indicating adaptive interactions between the N-glycans and underlying protein. Given the topology of the genetic code, mutation of (A is more often nonsynonomous, and Lys, another target of many PTMs, is also encoded by two (A-rich codons. An examination of acetyl-Lys sites in proteins indicated similar evolutionary dynamics, consistent with asymmetry of the target and recognition portions of modified sites. Our results suggest that encoding asymmetry is an ancient mechanism of evolvability that increases diversity and experimentation with PTM site positions. Strong selective pressures on PTMs may have

Enhancement of Ebola Virus Infection via Ficolin-1 Interaction with the Mucin Domain of GP Glycoprotein.

Science.gov (United States)

Favier, Anne-Laure; Gout, Evelyne; Reynard, Olivier; Ferraris, Olivier; Kleman, Jean-Philippe; Volchkov, Viktor; Peyrefitte, Christophe; Thielens, Nicole M

2016-06-01

Ebola virus infection requires the surface viral glycoprotein to initiate entry into the target cells. The trimeric glycoprotein is a highly glycosylated viral protein which has been shown to interact with host C-type lectin receptors and the soluble complement recognition protein mannose-binding lectin, thereby enhancing viral infection. Similarly to mannose-binding lectin, ficolins are soluble effectors of the innate immune system that recognize particular glycans at the pathogen surface. In this study, we demonstrate that ficolin-1 interacts with the Zaire Ebola virus (EBOV) glycoprotein, and we characterized this interaction by surface plasmon resonance spectroscopy. Ficolin-1 was shown to bind to the viral glycoprotein with a high affinity. This interaction was mediated by the fibrinogen-like recognition domain of ficolin-1 and the mucin-like domain of the viral glycoprotein. Using a ficolin-1 control mutant devoid of sialic acid-binding capacity, we identified sialylated moieties of the mucin domain to be potential ligands on the glycoprotein. In cell culture, using both pseudotyped viruses and EBOV, ficolin-1 was shown to enhance EBOV infection independently of the serum complement. We also observed that ficolin-1 enhanced EBOV infection on human monocyte-derived macrophages, described to be major viral target cells,. Competition experiments suggested that although ficolin-1 and mannose-binding lectin recognized different carbohydrate moieties on the EBOV glycoprotein, the observed enhancement of the infection likely depended on a common cellular receptor/partner. In conclusion, ficolin-1 could provide an alternative receptor-mediated mechanism for enhancing EBOV infection, thereby contributing to viral subversion of the host innate immune system. A specific interaction involving ficolin-1 (M-ficolin), a soluble effector of the innate immune response, and the glycoprotein (GP) of EBOV was identified. Ficolin-1 enhanced virus infection instead of tipping the

Cancer Biomarker Discovery: Lectin-Based Strategies Targeting Glycoproteins

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David Clark

2012-01-01

Full Text Available Biomarker discovery can identify molecular markers in various cancers that can be used for detection, screening, diagnosis, and monitoring of disease progression. Lectin-affinity is a technique that can be used for the enrichment of glycoproteins from a complex sample, facilitating the discovery of novel cancer biomarkers associated with a disease state.

The Lyssavirus glycoprotein: A key to cross-immunity.

Science.gov (United States)

Buthelezi, Sindisiwe G; Dirr, Heini W; Chakauya, Ereck; Chikwamba, Rachel; Martens, Lennart; Tsekoa, Tsepo L; Stoychev, Stoyan H; Vandermarliere, Elien

2016-11-01

Rabies is an acute viral encephalomyelitis in warm-blooded vertebrates, caused by viruses belonging to Rhabdovirus family and genus Lyssavirus. Although rabies is categorised as a neglected disease, the rabies virus (RABV) is the most studied amongst Lyssaviruses which show nearly identical infection patterns. In efforts to improving post-exposure prophylaxis, several anti-rabies monoclonal antibodies (mAbs) targeting the glycoprotein (G protein) sites I, II, III and G5 have been characterized. To explore cross-neutralization capacity of available mAbs and discover new possible B-cell epitopes, we have analyzed all available glycoprotein sequences from Lyssaviruses with a focus on sequence variation and conservation. This information was mapped on the structure of a representative G protein. We proposed several possible cross-neutralizing B-cell epitopes (GUVTTTF, WLRTV, REECLD and EHLVVEEL) in complement to the already well-characterized antigenic sites. The research could facilitate development of novel cross-reactive mAbs against RABV and even more broad, against possibly all Lyssavirus members. Copyright © 2016 Elsevier Inc. All rights reserved.

Identifying the Viral Genes Encoding Envelope Glycoproteins for Differentiation of Cyprinid herpesvirus 3 Isolates

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Se Chang Park

2013-01-01

Full Text Available Cyprinid herpes virus 3 (CyHV-3 diseases have been reported around the world and are associated with high mortalities of koi (Cyprinus carpio. Although little work has been conducted on the molecular analysis of this virus, glycoprotein genes identified in the present study seem to be valuable targets for genetic comparison of this virus. Three envelope glycoprotein genes (ORF25, 65 and 116 of the CyHV-3 isolates from the USA, Israel, Japan and Korea were compared, and interestingly, sequence insertions or deletions were observed in these target regions. In addition, polymorphisms were presented in microsatellite zones from two glycoprotein genes (ORF65 and 116. In phylogenetic tree analysis, the Korean isolate was remarkably distinguished from USA, Israel, Japan isolates. These findings may be suitable for many applications including isolates differentiation and phylogeny studies.

Identifying the Viral Genes Encoding Envelope Glycoproteins for Differentiation of Cyprinid herpesvirus 3 Isolates

Science.gov (United States)

Han, Jee Eun; Kim, Ji Hyung; Renault, Tristan; Choresca, Casiano; Shin, Sang Phil; Jun, Jin Woo; Park, Se Chang

2013-01-01

Cyprinid herpes virus 3 (CyHV-3) diseases have been reported around the world and are associated with high mortalities of koi (Cyprinus carpio). Although little work has been conducted on the molecular analysis of this virus, glycoprotein genes identified in the present study seem to be valuable targets for genetic comparison of this virus. Three envelope glycoprotein genes (ORF25, 65 and 116) of the CyHV-3 isolates from the USA, Israel, Japan and Korea were compared, and interestingly, sequence insertions or deletions were observed in these target regions. In addition, polymorphisms were presented in microsatellite zones from two glycoprotein genes (ORF65 and 116). In phylogenetic tree analysis, the Korean isolate was remarkably distinguished from USA, Israel, Japan isolates. These findings may be suitable for many applications including isolates differentiation and phylogeny studies. PMID:23435236

Pituitary-hormone secretion by thyrotropinomas.

Science.gov (United States)

Roelfsema, Ferdinand; Kok, Simon; Kok, Petra; Pereira, Alberto M; Biermasz, Nienke R; Smit, Jan W; Frolich, Marijke; Keenan, Daniel M; Veldhuis, Johannes D; Romijn, Johannes A

2009-01-01

Hormone secretion by somatotropinomas, corticotropinomas and prolactinomas exhibits increased pulse frequency, basal and pulsatile secretion, accompanied by greater disorderliness. Increased concentrations of growth hormone (GH) or prolactin (PRL) are observed in about 30% of thyrotropinomas leading to acromegaly or disturbed sexual functions beyond thyrotropin (TSH)-induced hyperthyroidism. Regulation of non-TSH pituitary hormones in this context is not well understood. We there therefore evaluated TSH, GH and PRL secretion in 6 patients with up-to-date analytical and mathematical tools by 24-h blood sampling at 10-min intervals in a clinical research laboratory. The profiles were analyzed with a new deconvolution method, approximate entropy, cross-approximate entropy, cross-correlation and cosinor regression. TSH burst frequency and basal and pulsatile secretion were increased in patients compared with controls. TSH secretion patterns in patients were more irregular, but the diurnal rhythm was preserved at a higher mean with a 2.5 h phase delay. Although only one patient had clinical acromegaly, GH secretion and IGF-I levels were increased in two other patients and all three had a significant cross-correlation between the GH and TSH. PRL secretion was increased in one patient, but all patients had a significant cross-correlation with TSH and showed decreased PRL regularity. Cross-ApEn synchrony between TSH and GH did not differ between patients and controls, but TSH and PRL synchrony was reduced in patients. We conclude that TSH secretion by thyrotropinomas shares many characteristics of other pituitary hormone-secreting adenomas. In addition, abnormalities in GH and PRL secretion exist ranging from decreased (joint) regularity to overt hypersecretion, although not always clinically obvious, suggesting tumoral transformation of thyrotrope lineage cells.

Glycoprotein Ibα clustering in platelet storage and function

NARCIS (Netherlands)

Gitz, E.

2013-01-01

Platelets are anucleated, discoid-shaped cells that play an essential role in the formation of a hemostatic plug to prevent blood loss from injured vessels. Initial platelet arrest at the damaged arterial vessel wall is mediated through the interaction between the platelet receptor glycoprotein (GP)

Glucocorticoid-regulated and constitutive trafficking of proteolytically processed cell surface-associated glycoproteins in wild type and variant rat hepatoma cells

International Nuclear Information System (INIS)

Amacher, S.L.; Goodman, L.J.; Bravo, D.A.; Wong, K.Y.; Goldfine, I.D.; Hawley, D.M.; Firestone, G.L.

1989-01-01

Glucocorticoids regulate the trafficking of mouse mammary tumor virus (MMTV) glycoproteins to the cell surface in the rat hepatoma cell line M1.54, but not in the immunoselected sorting variant CR4. To compare the localization of MMTV glycoproteins to another proteolytically processed glycoprotein, both wild type M1.54 cells and variant CR4 cells were transfected with a human insulin receptor (hIR) expression vector, pRSVhIR. The production of cell surface hIR was monitored in dexamethasone-treated and -untreated wild type M1.54 and variant CR4 cells by indirect immunofluorescence, direct plasma membrane immunoprecipitation, and by [125I] insulin binding. In both wild type and variant rat hepatoma cells, hIR were localized at the cell surface in the presence or in the absence of 1 microM dexamethasone. In contrast, the glucocorticoid-regulated trafficking of cell surface MMTV glycoproteins occurred only in wild type M1.54 cells. We conclude that the hIR, which undergoes posttranslational processing reactions similar to MMTV glycoproteins, does not require glucocorticoids to be transported to the plasma membrane and is representative of a subset of cell surface glycoproteins whose trafficking is constitutive in rat hepatoma cells. Thus, MMTV glycoproteins and hIR provide specific cell surface markers to characterize the glucocorticoid-regulated and constitutive sorting pathways

Inhibition of Histone Deacetylases Permits Lipopolysaccharide-Mediated Secretion of Bioactive IL-1β via a Caspase-1-Independent Mechanism.

Science.gov (United States)

Stammler, Dominik; Eigenbrod, Tatjana; Menz, Sarah; Frick, Julia S; Sweet, Matthew J; Shakespear, Melanie R; Jantsch, Jonathan; Siegert, Isabel; Wölfle, Sabine; Langer, Julian D; Oehme, Ina; Schaefer, Liliana; Fischer, Andre; Knievel, Judith; Heeg, Klaus; Dalpke, Alexander H; Bode, Konrad A

2015-12-01

Histone deacetylase (HDAC) inhibitors (HDACi) are clinically approved anticancer drugs that have important immune-modulatory properties. We report the surprising finding that HDACi promote LPS-induced IL-1β processing and secretion in human and murine dendritic cells and murine macrophages. HDACi/LPS-induced IL-1β maturation and secretion kinetics differed completely from those observed upon inflammasome activation. Moreover, this pathway of IL-1β secretion was dependent on caspase-8 but was independent of the inflammasome components NACHT, LRR, and PYD domains-containing protein 3, apoptosis-associated speck-like protein containing a carboxyl-terminal caspase-recruitment domain, and caspase-1. Genetic studies excluded HDAC6 and HDAC10 as relevant HDAC targets in this pathway, whereas pharmacological inhibitor studies implicated the involvement of HDAC11. Treatment of mice with HDACi in a dextran sodium sulfate-induced colitis model resulted in a strong increase in intestinal IL-1β, confirming that this pathway is also operative in vivo. Thus, in addition to the conventional inflammasome-dependent IL-1β cleavage pathway, dendritic cells and macrophages are capable of generating, secreting, and processing bioactive IL-1β by a novel, caspase-8-dependent mechanism. Given the widespread interest in the therapeutic targeting of IL-1β, as well as the use of HDACi for anti-inflammatory applications, these findings have substantial clinical implications. Copyright © 2015 by The American Association of Immunologists, Inc.

Replacement of the cytoplasmic domain alters sorting of a viral glycoprotein in polarized cells.

OpenAIRE

Puddington, L; Woodgett, C; Rose, J K

1987-01-01

The envelope glycoprotein (G protein) of vesicular stomatitis virus (VSV) is transported to the basolateral plasma membrane of polarized epithelial cells, whereas the hemagglutinin glycoprotein (HA protein) of influenza virus is transported to the apical plasma membrane. To determine if the cytoplasmic domain of VSV G protein might be important in directing G protein to the basolateral membrane, we derived polarized Madin-Darby canine kidney cell lines expressing G protein or G protein with i...

Semiquantum secret sharing using entangled states

International Nuclear Information System (INIS)

Li Qin; Chan, W. H.; Long Dongyang

2010-01-01

Secret sharing is a procedure for sharing a secret among a number of participants such that only the qualified subsets of participants have the ability to reconstruct the secret. Even in the presence of eavesdropping, secret sharing can be achieved when all the members are quantum. So what happens if not all the members are quantum? In this paper, we propose two semiquantum secret sharing protocols by using maximally entangled Greenberger-Horne-Zeilinger-type states in which quantum Alice shares a secret with two classical parties, Bob and Charlie, in a way that both parties are sufficient to obtain the secret, but one of them cannot. The presented protocols are also shown to be secure against eavesdropping.

HCV E2 glycoprotein: mutagenesis of N-linked glycosylation sites and its effects on E2 expression and processing

International Nuclear Information System (INIS)

Slater-Handshy, Tiffany; Droll, Deborah A.; Fan Xiaofeng; Di Bisceglie, Adrian M.; Chambers, Thomas J.

2004-01-01

An expression system for analysis of the synthesis and processing of the E2 glycoprotein of a hepatitis C virus (HCV) genotype 1a strain was developed in transiently transfected cells. E2 proteins representing the entire length of the protein, including the transmembrane segment (E2) as well as two truncated versions (E2 660 and E2 715 ), were characterized for acquisition of N-linked glycans and transport to the media of transfected cells. To investigate the utilization of the 10 potential N-linked glycosylation sites on this E2 protein, a series of mutations consisting of single or multiple (two, three, four or eight) ablations of asparagine residues in the background of the E2 660 construct were analyzed. E2 660 proteins harboring single or multiple site mutations were produced at levels similar to that of wild-type protein, but secretion of the single mutants was mildly diminished, and elimination of two or more sites dramatically reduced delivery of the protein to the media. Similar results were obtained in Huh-7 cells with respect to intracellular synthesis and secretion of the mutant proteins. Analysis of oligosaccharide composition using endoglycosidase digestion revealed that all of the glycan residues on the intracellular forms of E2 660 , E2 715 , and E2 contained N-linked glycans modified into high-mannose carbohydrates, in contrast to the secreted forms, which were endo H resistant. The parental E2 660 protein could be readily detected in Huh-7 cells using anti-polyhistidine or antibody to recombinant E2. In contrast, E2 660 lacking the eight N-linked glycans was expressed but not detectable with anti-E2 antibody, and proteins lacking four glycans exhibited reduced reactivity. These experiments provide direct evidence that the presence of multiple N-linked glycans is required for the proper folding of the E2 protein in the ER and secretory pathway as well as for formation of its antigenic structure

Probabilistic Infinite Secret Sharing

OpenAIRE

Csirmaz, László

2013-01-01

The study of probabilistic secret sharing schemes using arbitrary probability spaces and possibly infinite number of participants lets us investigate abstract properties of such schemes. It highlights important properties, explains why certain definitions work better than others, connects this topic to other branches of mathematics, and might yield new design paradigms. A probabilistic secret sharing scheme is a joint probability distribution of the shares and the secret together with a colle...

Review: Pichia pastoris represents an alternative for human glycoprotein production for therapeutic use. Fermentation strategies

Directory of Open Access Journals (Sweden)

Henry Córdoba Ruiz

2003-07-01

Full Text Available Producing human proteins in lower organisms' cells using recombinant technology represents a very promising approach for treating many diseases produced by a particular protein deficiency, including close to 40 lysosomal storage diseases. Although E. coli has been the first host successfully employed in expressing human recombinant proteins, it has some limitations owing to its inability to perform some post-traductional steps such as glycosylation. The yeast Saccharomyces cerevisiae (S. cerevisiae has thusbeen initially considered and used. However, S. cerevisiae glycosylates proteins in a very different way to human cells producing highly antigenic proteins and thus some other non-conventional yeasts such as Pichia pastoris have been used recently. Human protein expression is not assodated with growth in this system; growth may occur at high cell concentrations, increasing heterologous protein productivity and yield. The system employs a very efficient, methanol-induced promoter which may be used as sole carbon and energy source. Post-traductional modifications seem more similar to human cells than those produced by other non-mammalian systems used in producing human glycoproteins; they do not secrete large amounts of endogenous proteins, simplifying expressed protein purification. This review presents some strategies for producing heterologous proteins in high density cultures using P. pastoris as an expression system.

Efficacy of soluble glycoprotein fraction from Allium sativum purified by size exclusion chromatography on murine Schistosomiasis mansoni.

Science.gov (United States)

Aly, Ibrahim; Taher, Eman E; El-Sayed, Hoda; Mohammed, Faten A; ELnain, Gehan; Hamad, Rabab S; Bayoumy, Elsayed M

2017-06-01

In this work, the efficiency of crude MeOH extracts and soluble glycoprotein fraction of Allium sativum purified by size-exclusion chromatography (SEC) on parasitological, histopathological and some biochemical parameters in Schistosoma mansoni infected mice were investigated. Animals were infected by tail immersion with 100 cercariae/each mouse and divided into five groups in addition to the normal control. The results revealed a significant decrease in mean worm burden in all treated mice especially in the group treated with soluble glycoprotein fraction of A. sativum as compared to infected non-treated control with the disappearance of female worms. Administration of the studied extracts revealed remarkable amelioration in the levels of all the measured parameters in S. mansoni infected mice. In addition, treatment of mice with crude A. sativum MeOH extract and soluble glycoprotein fraction of A. sativum decreased significantly the activities of studied enzymes as compared to the infected untreated group. The highest degrees of enhancement in pathological changes was observed in the treated one with soluble glycoprotein fraction of A. sativum compared to the infected group represented by small sized, late fibro-cellular granuloma, the decrease in cellular constituents and degenerative changes in eggs. In conclusion, A. sativum treatment had effective schistosomicidal activities, through reduction of worm burden and tissue eggs, especially when it was given in purified glycoprotein fraction. Moreover, the soluble glycoprotein fraction of A. sativum largely modulates both the size and the number of granulomas. Copyright © 2017 Elsevier Ltd. All rights reserved.

Recombinant pestivirus E2 glycoproteins prevent viral attachment to permissive and non permissive cells with different efficiency.

Science.gov (United States)

Asfor, A S; Wakeley, P R; Drew, T W; Paton, D J

2014-08-30

Bovine viral diarrhoea virus (BVDV) is an economically important animal pathogen, which like other pestiviruses has similar molecular biological features to hepaciviruses, including human Hepatitis C virus. The pestivirus E2 glycoproteins are the major target for virus-neutralising antibodies, as well as playing a role in receptor binding and host range restriction. In this study, recombinant E2 glycoproteins (rE2) derived from three different pestivirus species were examined for their inhibitory effects on pestivirus infectivity in cell culture. Histidine-tagged rE2 glycoproteins of BVDV type 2 strain 178003, BVDV type 1 strain Oregon C24V and CSFV strain Alfort 187 were produced in Spodoptera frugiperda insect cells and purified under native conditions. The ability of rE2 glycoprotein to inhibit the infection of permissive cells by both homologous and heterologous virus was compared, revealing that the inhibitory effects of rE2 glycoproteins correlated with the predicted similarity of the E2 structures in the recombinant protein and the test virus. This result suggests that the sequence and structure of E2 are likely to be involved in the host specificity of pestiviruses at their point of uptake into cells. Copyright © 2014 Elsevier B.V. All rights reserved.

RSA-Based Secret Handshakes

OpenAIRE

Vergnaud , Damien

2006-01-01

A secret handshake mechanism allows two entities, members of a same group, to authenticate each other secretly. This primitive was introduced recently by Balfanz, Durfee, Shankar, Smetters, Staddon and Wong and, so far, all the schemes proposed are based on discrete log systems. This paper proposes three new secret handshake protocols secure against active impersonator and detector adversaries. Inspired by two RSA-based key agreement protocols introduced by Okamoto and Tanaka in 1989 and Gira...

Membrane glycoproteins of differentiating skeletal muscle cells

International Nuclear Information System (INIS)

Miller, K.R.; Remy, C.N.; Smith, P.B.

1987-01-01

The composition of N-linked glycoprotein oligosaccharides was studied in myoblasts and myotubes of the C2 muscle cell line. Oligosaccharides were radioactively labelled for 15 hr with [ 3 H] mannose and plasma membranes isolated. Ten glycopeptides were detected by SDS-PAGE and fluorography. The extent of labelling was 4-6 fold greater in myoblasts vs myotubes. A glycopeptide of Mr > 100,000 was found exclusively in myoblast membranes. Lectin chromatography revealed that the proportion of tri-, tetranntenary, biantennary and high mannose chains was similar throughout differentiation. The high mannose chain fraction was devoid of hybrid chains. The major high mannose chain contained nine mannose residues. The higher level of glycopeptide labelling in myoblasts vs myotubes corresponded to a 5-fold greater rate of protein synthesis. Pulse-chase experiments were used to follow the synthesis of the Dol-oligosaccharides. Myoblasts and myotubes labelled equivalently the glucosylated tetradecasaccharide but myoblasts labelled the smaller intermediates 3-4 greater than myotubes. Myoblasts also exhibited a 2-3 fold higher Dol-P dependent glycosyl transferase activity for chain elongation and Dol-sugar synthesis. Together these results show that the degree of protein synthesis and level of Dol-P are contributing factors in the higher capacity of myoblasts to produce N-glycoproteins compared to myotubes

Effect of an aqueous extract of Scoparia dulcis on plasma and tissue glycoproteins in streptozotocin induced diabetic rats.

Science.gov (United States)

Latha, M; Pari, L

2005-02-01

The influence of Scoparia dulcis, a traditionally used plant for the treatment of diabetes mellitus, was examined in streptozotocin diabetic rats on dearrangement in glycoprotein levels. Diabetes was induced in male Wistar rats by a single intraperitoneal injection of streptozotocin. An aqueous extract of Scoparia dulcis plant was administered orally for 6 weeks. The effect of the Scoparia dulcis extract on blood glucose, plasma insulin, plasma and tissue glycoproteins studied was in comparison to glibenclamide. The levels of blood glucose and plasma glycoproteins were increased significantly whereas the level of plasma insulin was significantly decreased in diabetic rats. There was a significant decrease in the level of sialic acid and elevated levels of hexose, hexosamine and fucose in the liver and kidney of streptozotocin diabetic rats. Oral administration of Scoparia dulcis plant extract (SPEt) to diabetic rats led to decreased levels of blood glucose and plasma glycoproteins. The levels of plasma insulin and tissue sialic acid were increased whereas the levels of tissue hexose, hexosamine and fucose were near normal. The present study indicates that Scoparia dulcis possesses a significant beneficial effect on glycoproteins in addition to its antidiabetic effect.

Comparative Profiling of Triple-Negative Breast Carcinomas Tissue Glycoproteome by Sequential Purification of Glycoproteins and Stable Isotope Labeling

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Xiang Chen

2016-01-01

Full Text Available Background: Women with triple negative breast cancers (TNBCs have a poor prognosis due to lack of suitable targeted therapies. Changes in the protein glycosylation are increasingly being recognized as an important modification associated with cancer etiology. Methods: In an attempt to identify TNBC biomarkers with greater diagnostic and prognostic capabilities, hydrazide- based chemistry method combined with LC-MS/MS were used to purify and identify N-linked glycopeptides or glycoproteins of tissues from TNBC patients. Results: A total of 550 unique N-linked glycoproteins were identified, among these proteins, 72 unique N-linked glycoproteins were significantly regulated in tumor tissues, of which 56 proteins were upregulated and 16 proteins were downregulated. To assess the validity of the results, three selected proteins including Vascular endothelial growth factor receptor 1, Insulin receptor, Tissue factor pathway inhibitor were selected for western blot analysis, and these proteins were found as potential biomarkers of TNBC. The top three pathways of differentially expressed glycoproteins participated in were caveolar-mediated endocytosis signaling, agrin interactions at neuromuscular junction and LXR/RXR activation. Conclusion: This work provides potential glycoprotein markers to function as a novel tissue-based biomarker for TNBC.

The dipeptide Pro-Asp promotes IGF-1 secretion and expression in hepatocytes by enhancing JAK2/STAT5 signaling pathway.

Science.gov (United States)

Wang, Songbo; Wang, Guoqing; Zhang, Mengyuan; Zhuang, Lu; Wan, Xiaojuan; Xu, Jingren; Wang, Lina; Zhu, Xiaotong; Gao, Ping; Xi, Qianyun; Zhang, Yongliang; Shu, Gang; Jiang, Qingyan

2016-11-15

It has been implicated that IGF-1 secretion can be regulated by dietary protein. However, whether the dipeptides, one of digested products of dietary protein, have influence on IGF-1 secretion remain largely unknown. Our study aimed to investigate the effects of the dipeptide Pro-Asp on IGF-1 secretion and expression in hepatocytes and to explore the possible underlying mechanisms. Our findings demonstrated that Pro-Asp promoted the secretion and gene expression of IGF-1 in HepG2 cells and primary porcine hepatocytes. Meanwhile, Pro-Asp activated the ERK and Akt signaling pathways, downstream of IGF-1. In addition, Pro-Asp enhanced GH-mediated JAK2/STAT5 signaling pathway, while inhibition of JAK2/STAT5 blocked the promotive effect of Pro-Asp on IGF-1 secretion and expression. Moreover, acute injection of Pro-Asp stimulated IGF-1 expression and activated JAK2/STAT5 signaling pathway in mice liver. Together, these results suggested that the dipeptide Pro-Asp promoted IGF-1 secretion and expression in hepatocytes by enhancing GH-mediated JAK2/STAT5 signaling pathway. Copyright © 2016. Published by Elsevier Ireland Ltd.

Cereal n-glycoproteins enrichment by lectin affinity monolithic chromatography

Czech Academy of Sciences Publication Activity Database

Flodrová, Dana; Bobálová, Janette; Laštovičková, Markéta

2016-01-01

Roč. 44, č. 2 (2016), s. 286-297 ISSN 0133-3720 R&D Projects: GA ČR(CZ) GPP503/12/P395 Institutional support: RVO:68081715 Keywords : barley * wheat * glycoprotein * mass spectrometry * lectin chromatography Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 0.496, year: 2016

Efficient multiparty quantum-secret-sharing schemes

International Nuclear Information System (INIS)

Xiao Li; Deng Fuguo; Long Guilu; Pan Jianwei

2004-01-01

In this work, we generalize the quantum-secret-sharing scheme of Hillery, Buzek, and Berthiaume [Phys. Rev. A 59, 1829 (1999)] into arbitrary multiparties. Explicit expressions for the shared secret bit is given. It is shown that in the Hillery-Buzek-Berthiaume quantum-secret-sharing scheme the secret information is shared in the parity of binary strings formed by the measured outcomes of the participants. In addition, we have increased the efficiency of the quantum-secret-sharing scheme by generalizing two techniques from quantum key distribution. The favored-measuring-basis quantum-secret-sharing scheme is developed from the Lo-Chau-Ardehali technique [H. K. Lo, H. F. Chau, and M. Ardehali, e-print quant-ph/0011056] where all the participants choose their measuring-basis asymmetrically, and the measuring-basis-encrypted quantum-secret-sharing scheme is developed from the Hwang-Koh-Han technique [W. Y. Hwang, I. G. Koh, and Y. D. Han, Phys. Lett. A 244, 489 (1998)] where all participants choose their measuring basis according to a control key. Both schemes are asymptotically 100% in efficiency, hence nearly all the Greenberger-Horne-Zeilinger states in a quantum-secret-sharing process are used to generate shared secret information

Associations between pregnancy-associated glycoproteins and pregnancy outcomes, milk yield, parity, and clinical diseases in high-producing dairy cows.

Science.gov (United States)

Mercadante, P M; Ribeiro, E S; Risco, C; Ealy, A D

2016-04-01

Pregnancy-associated glycoproteins (PAG) are produced by the ruminant placenta and secreted into the maternal circulation throughout pregnancy. The extent to which circulating PAG concentrations predict pregnancy outcomes was examined herein. Also, associations between circulating PAG concentrations and various production parameters and clinical diseases were evaluated. Lactating primiparous and multiparous Holstein cows (n=345) were bred via timed artificial insemination using a standard Ovsynch protocol. Pregnancy was diagnosed by transrectal ultrasonography at d 32, 46, and 74 of gestation. Blood was harvested at d 32 to determine plasma concentrations of PAG and progesterone. Cows pregnant at d 32 that subsequently lost their pregnancy at d 46 and 74 had reduced PAG concentrations. Both artificial insemination service number and parity were associated with plasma PAG concentrations. Concentration of PAG in plasma was greater for cows pregnant from their second or later breeding than those pregnant from the first breeding postpartum, and was increased for primiparous compared with multiparous. In addition, cows with greater milk yield had increased plasma PAG concentrations. No association was detected between body condition score and plasma PAG concentrations. Cows that experienced clinical metritis, metabolic problems, or left displacement abomasum in the early postpartum period preceding breeding had greater plasma PAG concentrations than cows not experiencing these clinical diseases. Also, cows with multiple clinical diseases had increased odds of pregnancy loss when compared with cows not experiencing clinical diseases. Odds ratio testing detected a tendency in the relationship between reduced milk yield and increased pregnancy loss. Collectively, these associations illustrate one feature of the early developing placenta that may predict pregnancy outcomes in dairy cattle. It is unclear if plasma PAG are actively involved with mediating pregnancy outcomes

Interaction of HTLV-1 Tax protein with calreticulin: implications for Tax nuclear export and secretion.

Science.gov (United States)

Alefantis, Timothy; Flaig, Katherine E; Wigdahl, Brian; Jain, Pooja

2007-05-01

Human T cell leukemia virus type 1 (HTLV-1) is the etiologic agent of adult T cell leukemia (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The HTLV-1 transcriptional transactivator protein Tax plays an integral role in virus replication and disease progression. Traditionally, Tax is described as a nuclear protein where it performs its primary role as a transcriptional transactivator. However, recent studies have clearly shown that Tax can also be localized to the cytoplasm where it has been shown to interact with a number of host transcription factors most notably NF-kappaB, constitutive expression of which is directly related to the T cell transforming properties of Tax in ATL patients. The presence of a functional nuclear export signal (NES) within Tax and the secretion of full-length Tax have also been demonstrated previously. Additionally, release of Tax from HTLV-1-infected cells and the presence of cell-free Tax was demonstrated in the CSF of HAM/TSP patients suggesting that the progression to HAM/TSP might be mediated by the ability of Tax to function as an extracellular cytokine. Therefore, in both ATL and HAM/TSP Tax nuclear export and nucleocytoplasmic shuttling may play a critical role, the mechanism of which remains unknown. In this study, we have demonstrated that the calcium binding protein calreticulin interacts with Tax by co-immunoprecipitation. This interaction was found to localize to a region at or near the nuclear membrane. In addition, differential expression of calreticulin was demonstrated in various cell types that correlated with their ability to retain cytoplasmic Tax, particularly in astrocytes. Finally, a comparison of a number of HTLV-1-infected T cell lines to non-infected T cells revealed higher expression of calreticulin in infected cells implicating a direct role for this protein in HTLV-1 infection.

Appearance and cellular distribution of lectin-like receptors for alpha 1-acid glycoprotein in the developing rat testis

DEFF Research Database (Denmark)

Andersen, U O; Bøg-Hansen, T C; Kirkeby, S

1996-01-01

A histochemical avidin-biotin technique with three different alpha 1-acid glycoprotein glycoforms showed pronounced alterations in the cellular localization of two alpha 1-acid glycoprotein lectin-like receptors during cell differentiation in the developing rat testis. The binding of alpha 1-acid...

The UL24 protein of herpes simplex virus 1 affects the sub-cellular distribution of viral glycoproteins involved in fusion

Energy Technology Data Exchange (ETDEWEB)

Ben Abdeljelil, Nawel; Rochette, Pierre-Alexandre; Pearson, Angela, E-mail: angela.pearson@iaf.inrs.ca

2013-09-15

Mutations in UL24 of herpes simplex virus type 1 can lead to a syncytial phenotype. We hypothesized that UL24 affects the sub-cellular distribution of viral glycoproteins involved in fusion. In non-immortalized human foreskin fibroblasts (HFFs) we detected viral glycoproteins B (gB), gD, gH and gL present in extended blotches throughout the cytoplasm with limited nuclear membrane staining; however, in HFFs infected with a UL24-deficient virus (UL24X), staining for the viral glycoproteins appeared as long, thin streaks running across the cell. Interestingly, there was a decrease in co-localized staining of gB and gD with F-actin at late times in UL24X-infected HFFs. Treatment with chemical agents that perturbed the actin cytoskeleton hindered the formation of UL24X-induced syncytia in these cells. These data support a model whereby the UL24 syncytial phenotype results from a mislocalization of viral glycoproteins late in infection. - Highlights: • UL24 affects the sub-cellular distribution of viral glycoproteins required for fusion. • Sub-cellular distribution of viral glycoproteins varies in cell-type dependent manner. • Drugs targeting actin microfilaments affect formation of UL24-related syncytia in HFFs.

Multiple genes encode the major surface glycoprotein of Pneumocystis carinii

DEFF Research Database (Denmark)

Kovacs, J A; Powell, F; Edman, J C

1993-01-01

The major surface antigen of Pneumocystis carinii, a life-threatening opportunistic pathogen in human immunodeficiency virus-infected patients, is an abundant glycoprotein that functions in host-organism interactions. A monoclonal antibody to this antigen is protective in animals, and thus this a...

Secretion management in the mechanically ventilated patient.

Science.gov (United States)

Branson, Richard D

2007-10-01

Secretion management in the mechanically ventilated patient includes routine methods for maintaining mucociliary function, as well as techniques for secretion removal. Humidification, mobilization of the patient, and airway suctioning are all routine procedures for managing secretions in the ventilated patient. Early ambulation of the post-surgical patient and routine turning of the ventilated patient are common secretion-management techniques that have little supporting evidence of efficacy. Humidification is a standard of care and a requisite for secretion management. Both active and passive humidification can be used. The humidifier selected and the level of humidification required depend on the patient's condition and the expected duration of intubation. In patients with thick, copious secretions, heated humidification is superior to a heat and moisture exchanger. Airway suctioning is the most important secretion removal technique. Open-circuit and closed-circuit suctioning have similar efficacy. Instilling saline prior to suctioning, to thin the secretions or stimulate a cough, is not supported by the literature. Adequate humidification and as-needed suctioning are the foundation of secretion management in the mechanically ventilated patient. Intermittent therapy for secretion removal includes techniques either to simulate a cough, to mechanically loosen secretions, or both. Patient positioning for secretion drainage is also widely used. Percussion and postural drainage have been widely employed for mechanically ventilated patients but have not been shown to reduce ventilator-associated pneumonia or atelectasis. Manual hyperinflation and insufflation-exsufflation, which attempt to improve secretion removal by simulating a cough, have been described in mechanically ventilated patients, but neither has been studied sufficiently to support routine use. Continuous lateral rotation with a specialized bed reduces atelectasis in some patients, but has not been shown

Incretin secretion: direct mechanisms

DEFF Research Database (Denmark)

Balk-Møller, Emilie; Holst, Jens Juul; Kuhre, Rune Ehrenreich

2014-01-01

The incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) are secreted from gastro-intestinal K- and L-cells, respectively, and play an important role in post-prandial blood glucose regulation. They do this by direct stimulation of the pancreatic β...... enzyme responsible for incretin degradation (dipeptidyl peptidase-4) is inhibited (drugs are already on the market) while the secretion of endogenous GLP-1 secretion is stimulated at the same time may prove particularly rewarding. In this section we review current knowledge on the mechanisms for direct...

Contribution of the basolateral isoform of the Na-K-2Cl- cotransporter (NKCC1/BSC2) to renin secretion

DEFF Research Database (Denmark)

Castrop, Hayo; Lorenz, John N; Hansen, Pernille B

2005-01-01

Acute administration of loop diuretics like furosemide leads to a stimulation of renin secretion, an effect thought to result from inhibition of Na-K-2Cl cotransporter (NKCC2)-mediated salt transport at the luminal surface of the macula densa (MD). However, loop diuretics also inhibit NKCC1......, the second isoform of the Na-K-2Cl cotransporter, with similar potency. In the present study, we examined the influence of furosemide on renin secretion in NKCC1-deficient mice to distinguish between effects of the loop diuretic involving NKCC2 and, by implication, the MD pathway, and effects that might...

Interleukin 10 in Helicobacter pylori associated gastritis: immunohistochemical localisation and in vitro effects on cytokine secretion

Science.gov (United States)

Bodger, K; Bromelow, K; Wyatt, J; Heatley, R

2001-01-01

Background/Aims—Interleukin 10 (IL-10) is a counterinflammatory peptide implicated in the downregulation of human intestinal immune responses. Enhanced secretion of IL-10 has been documented in gastric biopsy organ culture in Helicobacter pylori infection. This study aimed to define the cellular origins of IL-10 in H pylori associated gastritis, and to determine the effects of endogenous IL-10 on proinflammatory cytokine secretion in vitro. Methods—Endoscopic biopsies were obtained from the gastric antrum at endoscopy from patients with dyspepsia. Two pairs of antral biopsies were cultured in vitro for 24 hours, one pair in the presence of neutralising anti-IL-10 monoclonal antibody, the other pair as controls. The cytokine content of culture supernatants (tumour necrosis factor α (TNF-α), IL-6, and IL-8) was determined by enzyme linked immunosorbent assay and corrected for biopsy weight. Helicobacter pylori status was established by histology and biopsy urease test, and histopathology graded by the Sydney system. In a subgroup of patients, western blotting was used to establish CagA serological status. Immunohistochemistry for IL-10 was performed on formalin fixed tissues using a combination of microwave antigen retrieval and the indirect avidin–biotin technique. Immunoreactivity was scored semiquantitatively. Results—In vitro culture was performed in 41 patients: 31 with H pylori positive chronic gastritis and 10 H pylori negative. In vitro secretion of TNF-α, IL-6, and IL-8 for "control" biopsies was significantly higher in H pylori positive versus negative samples, with values of TNF-α and IL-6 correlating with the degree of active and chronic inflammation and being higher in CagA seropositive cases. No evidence for enhanced cytokine secretion was seen in biopsies cocultured in the presence of anti-IL-10 monoclonal antibody. Immunohistochemistry was performed in 29 patients, of whom 13 were H pylori positive. IL-10 immunoreactivity was observed in

Molecular organization in bacterial cell membranes. Specific labelling and topological distribution of glycoproteins and proteins in Streptomyces albus membranes

Energy Technology Data Exchange (ETDEWEB)

Larraga, V; Munoz, E [Consejo Superior de Investigaciones Cientificas, Madrid (Spain). Instituto de Biologia Celular

1975-05-01

The paper reports about an investigation into the question of the specific labelling and topological distribution of glycoproteins and proteins in Streptomyces albus membranes. The method of sample preparation is described: Tritium labelling of glycoproteins in protoplasts and membranes, iodination of proteins, trypsin treatment and polyacrylamide gel electrophoresis. The findings suggest an asymmetrical distribution of the glycoproteins in membranes and a weak accessibility to iodine label. A structural model of the plasma membranes of Streptomyces albus is proposed similar to the general 'fluid mosaic' model of Singer and Nicholson.

Regulation of Pancreatic Beta Cell Stimulus-Secretion Coupling by microRNAs

Directory of Open Access Journals (Sweden)

Jonathan L. S. Esguerra

2014-11-01

Full Text Available Increased blood glucose after a meal is countered by the subsequent increased release of the hypoglycemic hormone insulin from the pancreatic beta cells. The cascade of molecular events encompassing the initial sensing and transport of glucose into the beta cell, culminating with the exocytosis of the insulin large dense core granules (LDCVs is termed “stimulus-secretion coupling.” Impairment in any of the relevant processes leads to insufficient insulin release, which contributes to the development of type 2 diabetes (T2D. The fate of the beta cell, when exposed to environmental triggers of the disease, is determined by the possibility to adapt to the new situation by regulation of gene expression. As established factors of post-transcriptional regulation, microRNAs (miRNAs are well-recognized mediators of beta cell plasticity and adaptation. Here, we put focus on the importance of comprehending the transcriptional regulation of miRNAs, and how miRNAs are implicated in stimulus-secretion coupling, specifically those influencing the late stages of insulin secretion. We suggest that efficient beta cell adaptation requires an optimal balance between transcriptional regulation of miRNAs themselves, and miRNA-dependent gene regulation. The increased knowledge of the beta cell transcriptional network inclusive of non-coding RNAs such as miRNAs is essential in identifying novel targets for the treatment of T2D.

Generating Isoform-Specific Antibodies : Lessons from Nucleocytoplasmic Glycoprotein Skp1

NARCIS (Netherlands)

West, Christopher M.; Van Der Wel, Hanke; Chinoy, Zoiesha; Boons, Geert Jan; Gauthier, Ted J.; Taylor, Carol M.; Xu, Yuechi

2015-01-01

Antibodies that discriminate protein isoforms differing by modifications at specific amino acids have revolutionized studies of their functions. Skp1 is a novel nucleocytoplasmic glycoprotein that is hydroxylated at proline-143 and then O-glycosylated by a pentasaccharide attached via a GlcNAcα1,

Direct chemical modification and voltammetric detection of glycans in glycoproteins

Czech Academy of Sciences Publication Activity Database

Trefulka, Mojmír; Paleček, Emil

2014-01-01

Roč. 48, NOV2014 (2014), s. 52-55 ISSN 1388-2481 R&D Projects: GA ČR(CZ) GAP301/11/2055 Institutional support: RVO:68081707 Keywords : Glycoproteins * Chemical modification * Os(VI)L complexes Subject RIV: BO - Biophysics Impact factor: 4.847, year: 2014

Irradiation of rat brain reduces P-glycoprotein expression and function

NARCIS (Netherlands)

Bart, J.; Nagengast, W. B.; Coppes, R. P.; Wegman, T. D.; van der Graaf, W. T. A.; Groen, H. J. M.; Vaalburg, W.; de Vries, E. G. E.; Hendrikse, N. H.

2007-01-01

The blood - brain barrier ( BBB) hampers delivery of several drugs including chemotherapeutics to the brain. The drug efflux pump P- glycoprotein ( P- gp), expressed on brain capillary endothelial cells, is part of the BBB. P- gp expression on capillary endothelium decreases 5 days after brain

An unusual dependence of human herpesvirus-8 glycoproteins-induced cell-to-cell fusion on heparan sulfate

International Nuclear Information System (INIS)

Tiwari, Vaibhav; Darmani, Nissar A.; Thrush, Gerald R.; Shukla, Deepak

2009-01-01

Human herpesvirus-8 (HHV-8) is known to interact with cell surface heparan sulfate (HS) for entry into a target cell. Here we investigated the role of HS during HHV-8 glycoproteins-induced cell fusion. Interestingly, the observed fusion demonstrated an unusual dependence on HS as evident from following lines of evidence: (1) a significant reduction in cell-to-cell fusion occurred when target cells were treated with heparinase; (2) in a competition assay, when the effector cells expressing HHV-8 glycoproteins were challenged with soluble HS, cell-to-cell fusion was reduced; and, (3) co-expression of HHV-8 glycoproteins gH-gL on target cells resulted in inhibition of cell surface HS expression. Taken together, our results indicate that cell surface HS can play an additional role during HHV-8 pathogenesis.

An unusual dependence of human herpesvirus-8 glycoproteins-induced cell-to-cell fusion on heparan sulfate

Energy Technology Data Exchange (ETDEWEB)

Tiwari, Vaibhav [Department of Ophthalmology, University of Illinois at Chicago, Chicago, IL 60612 (United States); Department of Microbiology and Immunology, University of Illinois at Chicago, Chicago, IL 60612 (United States); Department of Basic Medical Sciences, College of Osteopathic Medicine of the Pacific and College of Optometry, Western University of Health Sciences, Pomona, CA 91766 (United States); Darmani, Nissar A.; Thrush, Gerald R. [Department of Basic Medical Sciences, College of Osteopathic Medicine of the Pacific and College of Optometry, Western University of Health Sciences, Pomona, CA 91766 (United States); Shukla, Deepak, E-mail: dshukla@uic.edu [Department of Ophthalmology, University of Illinois at Chicago, Chicago, IL 60612 (United States); Department of Microbiology and Immunology, University of Illinois at Chicago, Chicago, IL 60612 (United States)

2009-12-18

Human herpesvirus-8 (HHV-8) is known to interact with cell surface heparan sulfate (HS) for entry into a target cell. Here we investigated the role of HS during HHV-8 glycoproteins-induced cell fusion. Interestingly, the observed fusion demonstrated an unusual dependence on HS as evident from following lines of evidence: (1) a significant reduction in cell-to-cell fusion occurred when target cells were treated with heparinase; (2) in a competition assay, when the effector cells expressing HHV-8 glycoproteins were challenged with soluble HS, cell-to-cell fusion was reduced; and, (3) co-expression of HHV-8 glycoproteins gH-gL on target cells resulted in inhibition of cell surface HS expression. Taken together, our results indicate that cell surface HS can play an additional role during HHV-8 pathogenesis.

Contribution of the attachment G glycoprotein to pathogenicity and immunogenicity of avian metapneumovirus subgroup C.

Science.gov (United States)

Govindarajan, Dhanasekaran; Kim, Shin-Hee; Samal, Siba K

2010-03-01

Avian metapneumovirus (AMPV) causes an upper respiratory tract infection in turkeys leading to serious economic losses to the turkey industry. The G glycoprotein of AMPV is known to be associated with viral attachment and pathogenesis. In this study, we determined the role of the G glycoprotein in the pathogenicity and immunogenicity of AMPV strain Colorado (AMPV/CO). Recombinant AMPV/CO lacking the G protein (rAMPV/CO-deltaG) was generated using a reverse-genetics system. The recovered rAMPV/CO-deltaG replicated slightly better than did wild-type AMPV in Vero cells. However, deletion of the G gene in AMPV resulted in attenuation of the virus in turkeys. The mutant virus induced less-severe clinical signs and a weaker immune response in turkeys than did the wild-type AMPV. Our results suggest that the G glycoprotein is an important determinant for the pathogenicity and immunogenicity of AMPV.

Podoplanin - a small glycoprotein with many faces

OpenAIRE

Ugorski, Maciej; Dziegiel, Piotr; Suchanski, Jaroslaw

2016-01-01

Podoplanin is a small membrane glycoprotein with a large number of O-glycoside chains and therefore it belongs to mucin-type proteins. It can be found on the surface of many types of normal cells originating from various germ layers. It is present primarily on the endothelium of lymphatic vessels, type I pneumocytes and glomerular podocytes. Increased levels of podoplanin or its neo-expression have been found in numerous types of human carcinomas, but it is especially common in squamous cell ...

Nonlinear secret image sharing scheme.

Science.gov (United States)

Shin, Sang-Ho; Lee, Gil-Je; Yoo, Kee-Young

2014-01-01

Over the past decade, most of secret image sharing schemes have been proposed by using Shamir's technique. It is based on a linear combination polynomial arithmetic. Although Shamir's technique based secret image sharing schemes are efficient and scalable for various environments, there exists a security threat such as Tompa-Woll attack. Renvall and Ding proposed a new secret sharing technique based on nonlinear combination polynomial arithmetic in order to solve this threat. It is hard to apply to the secret image sharing. In this paper, we propose a (t, n)-threshold nonlinear secret image sharing scheme with steganography concept. In order to achieve a suitable and secure secret image sharing scheme, we adapt a modified LSB embedding technique with XOR Boolean algebra operation, define a new variable m, and change a range of prime p in sharing procedure. In order to evaluate efficiency and security of proposed scheme, we use the embedding capacity and PSNR. As a result of it, average value of PSNR and embedding capacity are 44.78 (dB) and 1.74t⌈log2 m⌉ bit-per-pixel (bpp), respectively.

[Research progress on ebola virus glycoprotein].

Science.gov (United States)

Ding, Guo-Yong; Wang, Zhi-Yu; Gao, Lu; Jiang, Bao-Fa

2013-03-01

Ebola virus (EBOV) causes outbreaks of a highly lethal hemorrhagic fever in humans and there are no effective therapeutic or prophylactic treatments available. The glycoprotein (GP) of EBOV is a transmembrane envelope protein known to play multiple functions including virus attachment and entry, cell rounding and cytotoxicity, down-regulation of host surface proteins, and enhancement of virus assembly and budding. GP is the primary target of protective immunity and the key target for developing neutralizing antibodies. In this paper, the research progress on genetic structure, pathogenesis and immunogenicity of EBOV GP in the last 5 years is reviewed.

Phosphorylation of varicella-zoster virus glycoprotein gpI by mammalian casein kinase II and casein kinase I

International Nuclear Information System (INIS)

Grose, C.; Jackson, W.; Traugh, J.A.

1989-01-01

Varicella-zoster virus (VZV) glycoprotein gpI is the predominant viral glycoprotein within the plasma membranes of infected cells. This viral glycoprotein is phosphorylated on its polypeptide backbone during biosynthesis. In this report, the authors investigated the protein kinases which participate in the phosphorylation events. Under in vivo conditions, VZV gpI was phosphorylated on its serine and threonine residues by protein kinases present within lysates of either VZV-infected or uninfected cells. Because this activity was diminished by heparin, a known inhibitor of casein kinase II, isolated gpI was incubated with purified casein kinase II and shown to be phosphorylated in an in vitro assay containing [γ- 32 P]ATP. The same glycoprotein was phosphorylated when [ 32 P]GTP was substituted for [ 32 P]ATP in the protein kinase assay. They also tested whether VZV gpI was phosphorylated by two other ubiquitous mammalian protein kinases--casein kinase I and cyclic AMP-dependent kinase--and found that only casein kinase I modified gpI. When the predicted 623-amino-acid sequence of gpI was examined, two phosphorylation sites known to be optimal for casein kinase II were observed. In summary, this study showed that VZV gpI was phosphorylated by each of two mammalian protein kinases (casein kinase I and casein kinase II) and that potential serine-threonine phosphorylation sites for each of these two kinases were present in the viral glycoprotein

Shared Secrets versus Secrets Kept Private Are Linked to Better Adolescent Adjustment

Science.gov (United States)

Frijns, Tom; Finkenauer, Catrin; Keijsers, Loes

2013-01-01

It is a household notion that secrecy is bad while sharing is good. But what about shared secrets? The present research adopts a functional analysis of sharing secrets, arguing that it should negate harmful consequences generally associated with secrecy and serves important interpersonal functions in adolescence. A survey study among 790 Dutch…

Development of Gonadotropin-Releasing Hormone-Secreting Neurons from Human Pluripotent Stem Cells

Directory of Open Access Journals (Sweden)

Carina Lund

2016-08-01

Full Text Available Gonadotropin-releasing hormone (GnRH neurons regulate human puberty and reproduction. Modeling their development and function in vitro would be of interest for both basic research and clinical translation. Here, we report a three-step protocol to differentiate human pluripotent stem cells (hPSCs into GnRH-secreting neurons. Firstly, hPSCs were differentiated to FOXG1, EMX2, and PAX6 expressing anterior neural progenitor cells (NPCs by dual SMAD inhibition. Secondly, NPCs were treated for 10 days with FGF8, which is a key ligand implicated in GnRH neuron ontogeny, and finally, the cells were matured with Notch inhibitor to bipolar TUJ1-positive neurons that robustly expressed GNRH1 and secreted GnRH decapeptide into the culture medium. The protocol was reproducible both in human embryonic stem cells and induced pluripotent stem cells, and thus provides a translational tool for investigating the mechanisms of human puberty and its disorders.

Urinary excretion of beta 2-glycoprotein-1 (apolipoprotein H) and other markers of tubular malfunction in "non-tubular" renal disease.

Science.gov (United States)

Flynn, F V; Lapsley, M; Sansom, P A; Cohen, S L

1992-07-01

To determine whether urinary beta 2-glycoprotein-1 assays can provide improved discrimination between chronic renal diseases which are primarily of tubular or glomerular origin. Urinary beta 2-glycoprotein-1, retinol-binding protein, alpha 1-microglobulin, beta 2-microglobulin, N-acetyl-beta-D-glucosa-minidase and albumin were measured in 51 patients with primary glomerular disease, 23 with obstructive nephropathy, and 15 with polycystic kidney disease, and expressed per mmol of creatinine. Plasma beta 2-glycoprotein-1 was assayed in 52 patients and plasma creatinine in all 89. The findings were compared between the diagnostic groups and with previously published data relating to primary tubular disorders. All 31 patients with plasma creatinine greater than 200 mumol/l excreted increased amounts of beta 2-glycoprotein-1, retinol-binding protein, and alpha 1-microglobulin, and 29 had increased N-acetyl-beta-D-glucosaminidase; the quantities were generally similar to those found in comparable patients with primary tubular pathology. Among 58 with plasma creatinine concentrations under 200 mumol/l, increases in beta 2-glycoprotein-1, retinol-binding protein, and alpha 1-microglobulin excretion were less common and much smaller, especially in those with obstructive nephropathy and polycystic disease. The ratios of the excretion of albumin to the other proteins provided the clearest discrimination between the patients with glomerular or tubular malfunction, but an area of overlap was present which embraced those with obstructive nephropathy and polycystic disease. Increased excretion of beta 2-glycoprotein-1 due to a raised plasma concentration or diminution of tubular reabsorption, or both, is common in all the forms of renal disease investigated, and both plasma creatinine and urinary albumin must be taken into account when interpreting results. Ratios of urinary albumin: beta 2-glycoprotein-1 greater than 1000 are highly suggestive of primary glomerular disease and

A sheep hydatid cyst glycoprotein as receptors for three toxic lectins, as well as Abrus precatorius and Ricinus communis agglutinins.

Science.gov (United States)

Wu, A M; Song, S C; Wu, J H; Pfüller, U; Chow, L P; Lin, J Y

1995-01-18

The binding properties of a glycoprotein with blood group P1 specificity isolated from sheep hydatid cyst fluid with Gal and GalNAc specific lectins was investigated by quantitative precipitin and precipitin inhibition assays. The glycoprotein completely precipitated Ricinus communis agglutinin (RCA1), Abrus precatorius agglutinin (APA) and Mistletoe toxic lectin-I (ML-I). Only 1.0 microgram of P1 glycoprotein was required to precipitate 50% of 5.1 micrograms ML-I nitrogen. It also reacted well with abrin-a and ricin, precipitating over 73% of the lectin nitrogen added, but poorly or weakly with Dolichos biflorus (DBL), Vicia villosa (VVL, a mixture of A4, A2B2 and B4), VVL-B4, Arachis hypogaea (PNA), Maclura pomifera (MPL), Bauchinia purpurea alba (BPL) and Wistaria floribunda (WFL) lectins. When an inhibition assay in the range of 5.1 micrograms N to 5.9 micrograms N of lectins (ML-I, abrin-a; ricin, RCA1, and APA, and 10 micrograms P1 active glycoprotein interaction was performed; from 76 to 100% of the precipitations were inhibited by 0.44 and 0.52 mumol of Gal alpha 1-->4Gal and Gal beta 1-->4GlcNAc, respectively, but not or insignificantly with 1.72 mumol of GlcNAc. The Gal alpha 1-->4Gal disaccharide found in this P1 active glycoprotein is a frequently occurring sequence of many glycosphingolipids located at the surface of mammalian cell membranes, especially human erythrocytes and intestinal cells for ligand binding and microbial toxin attachment. The present finding suggests that the Gal alpha 1-->4Gal beta 1-->4GlcNAc sequence in this P1 active glycoprotein is one of the best glycoprotein receptors for three toxic lectins (ricin, abrin-a, and ML-I) as well as for APA, and RCA1, and the result of inhibition assay implies that these lectins are recognizing part or all of the Gal alpha 1-->4Gal beta 1-->4GlcNAc sequence in the P1 active glycoprotein.

Isolation and characterization of broadly neutralizing human monoclonal antibodies to the e1 glycoprotein of hepatitis C virus

DEFF Research Database (Denmark)

Meunier, Jean-Christophe; Russell, Rodney S; Goossens, Vera

2008-01-01

monoclonal antibodies (MAbs) directed against HCV glycoprotein E1, which may have the potential to control HCV infection. We have identified two MAbs that can strongly neutralize HCV-pseudotyped particles (HCVpp) bearing the envelope glycoproteins of genotypes 1a, 1b, 4a, 5a, and 6a and less strongly...

On alternative approach for verifiable secret sharing

OpenAIRE

Kulesza, Kamil; Kotulski, Zbigniew; Pieprzyk, Joseph

2002-01-01

Secret sharing allows split/distributed control over the secret (e.g. master key). Verifiable secret sharing (VSS) is the secret sharing extended by verification capacity. Usually verification comes at the price. We propose "free lunch", the approach that allows to overcome this inconvenience.

Secrets of mlearning failures: confronting reality

Directory of Open Access Journals (Sweden)

Thomas Cochrane

2012-08-01

Full Text Available Having implemented and evaluated over 35 mlearning projects in a variety of contexts in higher education over the past 6 years the researcher is ready to share the untold secret: not all mlearning projects succeed! This article critiques three of the researcher's mlearning projects that can be classed as “failures” and compares them to successful projects to draw out critical implications for mlearning project design and implementation to avoid common pitfalls leading to potential project failure. This article uses the researcher's six critical success factors identified across the 35 mlearning projects to evaluate these three projects, and concludes that projects resulting in “no significant difference” in pedagogical outcomes are the result of attempts to shoehorn old pedagogies into new technologies. Lecturer professional development and sustained collaborative support are critical to fostering new pedagogies utilising the unique affordances of mobile devices.

Identification of a mouse synaptic glycoprotein gene in cultured neurons.

Science.gov (United States)

Yu, Albert Cheung-Hoi; Sun, Chun Xiao; Li, Qiang; Liu, Hua Dong; Wang, Chen Ran; Zhao, Guo Ping; Jin, Meilei; Lau, Lok Ting; Fung, Yin-Wan Wendy; Liu, Shuang

2005-10-01

Neuronal differentiation and aging are known to involve many genes, which may also be differentially expressed during these developmental processes. From primary cultured cerebral cortical neurons, we have previously identified various differentially expressed gene transcripts from cultured cortical neurons using the technique of arbitrarily primed PCR (RAP-PCR). Among these transcripts, clone 0-2 was found to have high homology to rat and human synaptic glycoprotein. By in silico analysis using an EST database and the FACTURA software, the full-length sequence of 0-2 was assembled and the clone was named as mouse synaptic glycoprotein homolog 2 (mSC2). DNA sequencing revealed transcript size of mSC2 being smaller than the human and rat homologs. RT-PCR indicated that mSC2 was expressed differentially at various culture days. The mSC2 gene was located in various tissues with higher expression in brain, lung, and liver. Functions of mSC2 in neurons and other tissues remain elusive and will require more investigation.

Trade Secrets in Life Science and Pharmaceutical Companies

Science.gov (United States)

Nealey, Tara; Daignault, Ronald M.; Cai, Yu

2015-01-01

Trade secret protection arises under state common law and state statutes. In general, a trade secret is information that is not generally known to the public and is maintained as a secret, and it provides a competitive advantage or economic benefit to the trade secret holder. Trade secrets can be worth tens or hundreds of millions of dollars, and damage awards in trade secret litigation have been high; often, there is a lot at stake. Obtaining a trade secret through “improper means” is misappropriation. If the alleged trade secret, however, was developed independently, known publicly, or not maintained as a secret, then those defenses may successfully overcome a claim for trade secret misappropriation. With today’s interconnectedness in the biotechnology and pharmaceutical fields, more collaborations, joint ventures, and outsourcing arrangements among firms, and increased mobility of employees’ careers, life science companies need to not only understand how to protect their trade secrets, but also know how to defend against a claim for trade secret theft. PMID:25414378

Trade secrets in life science and pharmaceutical companies.

Science.gov (United States)

Nealey, Tara; Daignault, Ronald M; Cai, Yu

2014-11-20

Trade secret protection arises under state common law and state statutes. In general, a trade secret is information that is not generally known to the public and is maintained as a secret, and it provides a competitive advantage or economic benefit to the trade secret holder. Trade secrets can be worth tens or hundreds of millions of dollars, and damage awards in trade secret litigation have been high; often, there is a lot at stake. Obtaining a trade secret through "improper means" is misappropriation. If the alleged trade secret, however, was developed independently, known publicly, or not maintained as a secret, then those defenses may successfully overcome a claim for trade secret misappropriation. With today's interconnectedness in the biotechnology and pharmaceutical fields, more collaborations, joint ventures, and outsourcing arrangements among firms, and increased mobility of employees' careers, life science companies need to not only understand how to protect their trade secrets, but also know how to defend against a claim for trade secret theft. Copyright © 2015 Cold Spring Harbor Laboratory Press; all rights reserved.

Intercellular transfer of P-glycoprotein from the drug resistant human bladder cancer cell line BIU-87 does not require cell-to-cell contact.

Science.gov (United States)

Zhou, Hui-liang; Zheng, Yong-jun; Cheng, Xiao-zhi; Lv, Yi-song; Gao, Rui; Mao, Hou-ping; Chen, Qin

2013-09-01

The efflux activity of transmembrane P-glycoprotein prevents various therapeutic drugs from reaching lethal concentrations in cancer cells, resulting in multidrug resistance. We investigated whether drug resistant bladder cancer cells could transfer functional P-glycoprotein to sensitive parental cells. Drug sensitive BIU-87 bladder cancer cells were co-cultured for 48 hours with BIU-87/ADM, a doxorubicin resistant derivative of the same cell line, in a Transwell® system that prevented cell-to-cell contact. The presence of P-glycoprotein in recipient cell membranes was established using fluorescein isothiocyanate, laser scanning confocal microscopy and Western blot. P-glycoprotein mRNA levels were compared between cell types. Rhodamine 123 efflux assay was done to confirm that P-glycoprotein was biologically active. The amount of P-glycoprotein protein in BIU-87 cells co-cultured with BIU-87/ADM was significantly higher than in BIU-87 cells (0.44 vs 0.25) and BIU-87/H33342 cells (0.44 vs 0.26, each p transfer. P-glycoprotein mRNA expression was significantly higher in BIU-87/ADM cells than in co-cultured BIU-87 cells (1.28 vs 0.30), BIU-87/H33342 (0.28) and BIU-87 cells (0.25, each p <0.001), ruling out a genetic mechanism. After 30 minutes of efflux, rhodamine 123 fluorescence intensity was significantly lower in BIU-87/ADM cells (5.55 vs 51.45, p = 0.004) and co-cultured BIU-87 cells than in BIU-87 cells (14.22 vs 51.45, p <0.001), indicating that P-glycoprotein was functional. Bladder cancer cells can acquire functional P-glycoprotein through a nongenetic mechanism that does not require direct cell contact. This mechanism is consistent with a microparticle mediated process. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Two-party secret key distribution via a modified quantum secret sharing protocol.

Science.gov (United States)

Grice, W P; Evans, P G; Lawrie, B; Legré, M; Lougovski, P; Ray, W; Williams, B P; Qi, B; Smith, A M

2015-03-23

We present and demonstrate a novel protocol for distributing secret keys between two and only two parties based on N-party single-qubit Quantum Secret Sharing (QSS). We demonstrate our new protocol with N = 3 parties using phase-encoded photons. We show that any two out of N parties can build a secret key based on partial information from each other and with collaboration from the remaining N - 2 parties. Our implementation allows for an accessible transition between N-party QSS and arbitrary two party QKD without modification of hardware. In addition, our approach significantly reduces the number of resources such as single photon detectors, lasers and dark fiber connections needed to implement QKD.

p120-catenin differentially regulates cell migration by Rho-dependent intracellular and secreted signals

DEFF Research Database (Denmark)

Epifano, Carolina; Megias, Diego; Perez-Moreno, Mirna

2014-01-01

The adherens junction protein p120-catenin is implicated in the regulation of cadherin stability, cell migration and inflammatory responses in mammalian epithelial tissues. How these events are coordinated to promote wound repair is not understood. We show that p120 catenin regulates the intrinsic...... migratory properties of primary mouse keratinocytes, but also influences the migratory behavior of neighboring cells by secreted signals. These events are rooted in the ability of p120-catenin to regulate RhoA GTPase activity, which leads to a two-tiered control of cell migration. One restrains cell...... motility via an increase in actin stress fibers, reduction in integrin turnover and an increase in the robustness of focal adhesions. The other is coupled to the secretion of inflammatory cytokines including interleukin-24, which causally enhances randomized cell movements. Taken together, our results...

An unusual dependence of human herpesvirus-8 Glycoproteins-induced cell-to-cell fusion on heparan sulfate

Science.gov (United States)

Tiwari, Vaibhav; Darmani, Nissar A.; Thrush, Gerald R.; Shukla, Deepak

2009-01-01

Human herpes virus 8 (HHV-8) is known to interact with cell surface heparan sulfate (HS) for entry into a target cell. Here we investigated the role of HS during HHV-8 glycoproteins induced cell fusion. Interestingly, the observed fusion demonstrated an unusual dependence on HS as evident from following lines of evidence: 1) a significant reduction in cell-to-cell fusion occurred when target cells were treated with heparinase; 2) in a competition assay, when the effector cells expressing HHV-8 glycoproteins were challenged with soluble HS, cell-to-cell fusion was reduced; and, 3) coexpression of HHV-8 glycoproteins gH-gL on target cells resulted in inhibition of cell surface HS expression. Taken together, our results indicate that cell surface HS can play an additional role during HHV-8 pathogenesis. PMID:19747451

Comparative Analysis of Whey N-Glycoproteins in Human Colostrum and Mature Milk Using Quantitative Glycoproteomics.

Science.gov (United States)

Cao, Xueyan; Song, Dahe; Yang, Mei; Yang, Ning; Ye, Qing; Tao, Dongbing; Liu, Biao; Wu, Rina; Yue, Xiqing

2017-11-29

Glycosylation is a ubiquitous post-translational protein modification that plays a substantial role in various processes. However, whey glycoproteins in human milk have not been completely profiled. Herein, we used quantitative glycoproteomics to quantify whey N-glycosylation sites and their alteration in human milk during lactation; 110 N-glycosylation sites on 63 proteins and 91 N-glycosylation sites on 53 proteins were quantified in colostrum and mature milk whey, respectively. Among these, 68 glycosylation sites on 38 proteins were differentially expressed in human colostrum and mature milk whey. These differentially expressed N-glycoproteins were highly enriched in "localization", "extracellular region part", and "modified amino acid binding" according to gene ontology annotation and mainly involved in complement and coagulation cascades pathway. These results shed light on the glycosylation sites, composition and biological functions of whey N-glycoproteins in human colostrum and mature milk, and provide substantial insight into the role of protein glycosylation during infant development.

Molecular cloning of S1 glycoprotein gene of infectious bronchitis ...

African Journals Online (AJOL)

In vitro protein expression is an important method of obtaining large amounts of viral proteins to investigate their biological properties. The S1 glycoprotein of infectious bronchitis virus, due to its effective immune-dominant role is an appropriate candidate for production of recombinant vaccine against infectious bronchitis ...

The Lyssavirus glycoprotein: A key to cross-immunity

International Nuclear Information System (INIS)

Buthelezi, Sindisiwe G.; Dirr, Heini W.; Chakauya, Ereck; Chikwamba, Rachel; Martens, Lennart; Tsekoa, Tsepo L.; Stoychev, Stoyan H.; Vandermarliere, Elien

2016-01-01

Rabies is an acute viral encephalomyelitis in warm-blooded vertebrates, caused by viruses belonging to Rhabdovirus family and genus Lyssavirus. Although rabies is categorised as a neglected disease, the rabies virus (RABV) is the most studied amongst Lyssaviruses which show nearly identical infection patterns. In efforts to improving post-exposure prophylaxis, several anti-rabies monoclonal antibodies (mAbs) targeting the glycoprotein (G protein) sites I, II, III and G5 have been characterized. To explore cross-neutralization capacity of available mAbs and discover new possible B-cell epitopes, we have analyzed all available glycoprotein sequences from Lyssaviruses with a focus on sequence variation and conservation. This information was mapped on the structure of a representative G protein. We proposed several possible cross-neutralizing B-cell epitopes (GUVTTTF, WLRTV, REECLD and EHLVVEEL) in complement to the already well-characterized antigenic sites. The research could facilitate development of novel cross-reactive mAbs against RABV and even more broad, against possibly all Lyssavirus members. -- Highlights: •The current PEP has raised safety and availability concerns. •Cocktails of mAbs have been proposed as alternative treatment. •Amino acid conservation amongst Lyssavirus G proteins was studied. •Possible cross-neutralizing B-cell epitopes were proposed.

The Lyssavirus glycoprotein: A key to cross-immunity

Energy Technology Data Exchange (ETDEWEB)

Buthelezi, Sindisiwe G. [Council for Scientific and Industrial Research, Biosciences Unit, Pretoria (South Africa); Protein Structure-Function Research Unit, School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg (South Africa); Dirr, Heini W. [Protein Structure-Function Research Unit, School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg (South Africa); Chakauya, Ereck; Chikwamba, Rachel [Council for Scientific and Industrial Research, Biosciences Unit, Pretoria (South Africa); Martens, Lennart [Unit for Computational Omics and Systems Biology, Medical Biotechnology Center, VIB, Ghent (Belgium); Department of Biochemistry, Faculty of Medicine and Health Sciences, Ghent University, Ghent (Belgium); Tsekoa, Tsepo L. [Council for Scientific and Industrial Research, Biosciences Unit, Pretoria (South Africa); Stoychev, Stoyan H., E-mail: Sstoychev@csir.co.za [Council for Scientific and Industrial Research, Biosciences Unit, Pretoria (South Africa); Vandermarliere, Elien [Unit for Computational Omics and Systems Biology, Medical Biotechnology Center, VIB, Ghent (Belgium); Department of Biochemistry, Faculty of Medicine and Health Sciences, Ghent University, Ghent (Belgium); Bioinformatics Institute Gent, Ghent University, Ghent (Belgium)

2016-11-15

Rabies is an acute viral encephalomyelitis in warm-blooded vertebrates, caused by viruses belonging to Rhabdovirus family and genus Lyssavirus. Although rabies is categorised as a neglected disease, the rabies virus (RABV) is the most studied amongst Lyssaviruses which show nearly identical infection patterns. In efforts to improving post-exposure prophylaxis, several anti-rabies monoclonal antibodies (mAbs) targeting the glycoprotein (G protein) sites I, II, III and G5 have been characterized. To explore cross-neutralization capacity of available mAbs and discover new possible B-cell epitopes, we have analyzed all available glycoprotein sequences from Lyssaviruses with a focus on sequence variation and conservation. This information was mapped on the structure of a representative G protein. We proposed several possible cross-neutralizing B-cell epitopes (GUVTTTF, WLRTV, REECLD and EHLVVEEL) in complement to the already well-characterized antigenic sites. The research could facilitate development of novel cross-reactive mAbs against RABV and even more broad, against possibly all Lyssavirus members. -- Highlights: •The current PEP has raised safety and availability concerns. •Cocktails of mAbs have been proposed as alternative treatment. •Amino acid conservation amongst Lyssavirus G proteins was studied. •Possible cross-neutralizing B-cell epitopes were proposed.

Glycoprotein profiles of macrophages at different stages of activation as revealed by lectin binding after electrophoretic separation.

Science.gov (United States)

Irimura, T; North, S M; Nicolson, G L

1987-01-01

Glycoprotein profiles of rat macrophages (M phi) at different stages of activation were studied by examining the reactivity of various lectins to the glycoproteins separated by polyacrylamide gel electrophoresis. Ricinus communis agglutinin 1 (RCA1) revealed several components including glycoproteins of Mr 160 kDa and 65 kDa prominent in resident M phi. A pokeweed mitogen (PWM) isolectin, Pa-4, recognizes branched poly(N-acetyllactosamine)-type carbohydrate chains, and revealed a significant increase in glycoproteins of Mr ranging from 70 kDa to 150 kDa on thioglycolate-elicited M phi. Increased reactivity of PWM to thioglycolate-elicited M phi was observed by direct binding of 125I-labeled Pa-4 to intact or glutaraldehyde-fixed M phi. Histochemical staining of formaldehyde-fixed M phi in vitro with biotinylated Pa-4 was consistent with the gel analysis, that is, resident M phi had no reactivity while thioglycolate-elicited M phi showed slight reactivity. Alveolar and intratumoral M phi bound more Pa-4 than resident or thioglycolate-elicited M phi. The PWM isolectin may therefore serve as a marker for an early stage of M phi activation.

5 CFR 1312.27 - Top secret control.

Science.gov (United States)

2010-01-01

... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Top secret control. 1312.27 Section 1312... Classified Information § 1312.27 Top secret control. The EOP Security Officer serves as the Top Secret... Top Secret material. The ATSCOs will be responsible for the accountability and custodianship of Top...

N-terminal sequence of human leukocyte glycoprotein Mo1: conservation across species and homology to platelet IIb/IIIa.

Science.gov (United States)

Pierce, M W; Remold-O'Donnell, E; Todd, R F; Arnaout, M A

1986-12-12

Mo1 and gp160-gp93 are two surface membrane glycoprotein heterodimers present on granulocytes and monocytes derived from humans and guinea pigs, respectively. We purified both antigens and found that their alpha subunits had identical N-termini which were significantly homologous to the alpha subunit of the human adhesion platelet glycoprotein IIb/IIIa.

Effect of adrenal hormones on thyroid secretion and thyroid hormones on adrenal secretion in the sheep.

Science.gov (United States)

Falconer, I R; Jacks, F

1975-01-01

1. Previous work has shown that after stressful stimuli, sheep initially secrete increased amounts of thyroid hormone, at a time when adrenal secretion is also elevated. 2. This study was designed to evaluate (a) any short-term activation or inhibition of thyroid secretion by exogenous cortisol or ACTH administered in quantities comparable to those secreted after stress in sheep and (b) any short-term effect that exogenous thyroxine or triiodothyronine may have on the concentration of plasma cortisol in the sheep. 3. Thyroid activity was measured by determination of plasma protein bound 125I (PB125I) and total 125I in thyroid vein and mixed venous (jugular) blood. Plasma cortisol and thyroxine concentrations were measured by a competitive protein-binding assay at intervals for up to 5 hr after commencement of the experiment. 4. No evidence of an activation of thyroid secretion was found during cortisol or ACTH infusion, as monitored by thyroid vein PB125I. Similarly there was no evidence of any inhibition of thyroid function, as measured by continued secretion of thyroid hormones into thyroid vein blood. 5. No effect on plasma cortisol concentration due to thyroid hormone treatment was observed. 6. It was concluded that (a) elevated circulating corticosteroids in physiological concentrations have no short-term effects on thyroid activity in the sheep and (b) the short-term alterations in thyroid and adrenal cortical secretion observed during stress in the sheep could not be attributed to direct interaction of elevated thyroid hormone concentrations with adrenal cortical secretion. PMID:170400

Secretion Trap Tagging of Secreted and Membrane-Spanning Proteins Using Arabidopsis Gene Traps

Science.gov (United States)

Andrew T. Groover; Joseph R. Fontana; Juana M. Arroyo; Cristina Yordan; W. Richard McCombie; Robert A. Martienssen

2003-01-01

Secreted and membrane-spanning proteins play fundamental roles in plant development but pose challenges for genetic identification and characterization. We describe a "secretion trap" screen for gene trap insertions in genes encoding proteins routed through the secretory pathway. The gene trap transposon encodes a ß-glucuronidase reporter enzyme...

The hypobranchial mucin of the whelk Buccinum undatum L. Properties of the mucin and of the glycoprotein component.

Science.gov (United States)

Hunt, S; Jevons, F R

1965-12-01

1. The composition of the hypobranchial mucin from Buccinum undatum is reported. 2. The amino acid composition was determined; aspartic acid and glutamic acid contribute almost 24% of the total amino acids in the mucin. 3. Serine, threonine and alanine, in the proportions 2:1:1 respectively, were detected as N-terminal residues, implying the presence of at least four protein chains. 4. A glycoprotein component was isolated by phenol precipitation. 5. The glycoprotein contained 8% of neutral sugars comprising glucose, galactose, mannose and fucose, and 4.5% of hexosamine, comprising glucosamine and galactosamine in equal proportions. 6. A method is described for the preparation of glycopeptides from the glycoprotein. 7. The comparative biochemistry of the mucin is discussed.

22 CFR 1421.15 - Secret ballot.

Science.gov (United States)

2010-04-01

... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Secret ballot. 1421.15 Section 1421.15 Foreign Relations FOREIGN SERVICE LABOR RELATIONS BOARD; FEDERAL LABOR RELATIONS AUTHORITY; GENERAL COUNSEL OF THE... THIS SUBCHAPTER § 1421.15 Secret ballot. Secret ballot means the expression by ballot, voting machine...

The mitochondrial translocator protein, TSPO, inhibits HIV-1 envelope glycoprotein biosynthesis via the endoplasmic reticulum-associated protein degradation pathway.

Science.gov (United States)

Zhou, Tao; Dang, Ying; Zheng, Yong-Hui

2014-03-01

The HIV-1 Env glycoprotein is folded in the endoplasmic reticulum (ER), which is necessary for viral entry and replication. Currently, it is still unclear how this process is regulated. The glycoprotein folding in the ER is controlled by the ER-associated protein degradation (ERAD) pathway, which specifically targets misfolded proteins for degradation. Previously, we reported that HIV-1 replication is restricted in the human CD4(+) T cell line CEM.NKR (NKR). To understand this mechanism, we first analyzed cellular protein expression in NKR cells and discovered that levels of the mitochondrial translocator protein TSPO were upregulated by ∼64-fold. Notably, when NKR cells were treated with TSPO antagonist PK-11195, Ro5-4864, or diazepam, HIV restriction was completely disrupted, and TSPO knockdown by short hairpin RNAs (shRNAs) achieved a similar effect. We next analyzed viral protein expression, and, interestingly, we discovered that Env expression was specifically inhibited. Both TSPO knockdown and treatment with TSPO antagonist could restore Env expression in NKR cells. We further discovered that Env proteins were rapidly degraded and that kifunensine, an ERAD pathway inhibitor, could restore Env expression and viral replication, indicating that Env proteins were misfolded and degraded through the ERAD pathway in NKR cells. We also knocked out the TSPO gene in 293T cells using CRISPR/Cas9 (clustered, regularly interspaced, short palindromic repeat [CRISPR]/CRISPR-associated-9) technology and found that TSPO could similarly inhibit Env expression in these cells. Taken together, these results demonstrate that TSPO inhibits Env protein expression through the ERAD pathway and suggest that mitochondria play an important role in regulating the Env folding process. The HIV-1 Env glycoprotein is absolutely required for viral infection, and an understanding of its expression pathway in infected cells will identify new targets for antiretroviral therapies. Env proteins

Co-assembly of viral envelope glycoproteins regulates their polarized sorting in neurons.

Directory of Open Access Journals (Sweden)

Rafael Mattera

2014-05-01

Full Text Available Newly synthesized envelope glycoproteins of neuroinvasive viruses can be sorted in a polarized manner to the somatodendritic and/or axonal domains of neurons. Although critical for transneuronal spread of viruses, the molecular determinants and interregulation of this process are largely unknown. We studied the polarized sorting of the attachment (NiV-G and fusion (NiV-F glycoproteins of Nipah virus (NiV, a paramyxovirus that causes fatal human encephalitis, in rat hippocampal neurons. When expressed individually, NiV-G exhibited a non-polarized distribution, whereas NiV-F was specifically sorted to the somatodendritic domain. Polarized sorting of NiV-F was dependent on interaction of tyrosine-based signals in its cytosolic tail with the clathrin adaptor complex AP-1. Co-expression of NiV-G with NiV-F abolished somatodendritic sorting of NiV-F due to incorporation of NiV-G•NiV-F complexes into axonal transport carriers. We propose that faster biosynthetic transport of unassembled NiV-F allows for its proteolytic activation in the somatodendritic domain prior to association with NiV-G and axonal delivery of NiV-G•NiV-F complexes. Our study reveals how interactions of viral glycoproteins with the host's transport machinery and between themselves regulate their polarized sorting in neurons.

Use of a fragment of glycoprotein G-2 produced in the baculovirus expression system for detecting herpes simplex virus type 2-specific antibodies

NARCIS (Netherlands)

Ikoma, M; Liljeqvist, JA; Glazenburg, KL; The, TH; Welling-Wester, S; Groen, J.

Fragments of glycoprotein G (gG-2(281-594His)), comprising residues 281 to 594 of herpes simplex virus type 2 (HSV-2), glycoprotein G of HSV-1 (gG-1(t26-189His)), and glycoprotein D of HSV-1 (gD-1(1-313)), were expressed in the baculovirus expression system to develop an assay for the detection of

Mechanical circulatory support is associated with loss of platelet receptors glycoprotein Ibα and glycoprotein VI.

Science.gov (United States)

Lukito, P; Wong, A; Jing, J; Arthur, J F; Marasco, S F; Murphy, D A; Bergin, P J; Shaw, J A; Collecutt, M; Andrews, R K; Gardiner, E E; Davis, A K

2016-11-01

Essentials Relationship of acquired von Willebrand disease (VWD) and platelet dysfunction is explored. Patients with ventricular assist devices and on extracorporeal membrane oxygenation are investigated. Acquired VWD and platelet receptor shedding is demonstrated in the majority of patients. Loss of platelet adhesion receptors glycoprotein (GP) Ibα and GPVI may increase bleeding risk. Background Ventricular assist devices (VADs) and extracorporeal membrane oxygenation (ECMO) are associated with bleeding that is not fully explained by anticoagulant or antiplatelet use. Exposure of platelets to elevated shear in vitro leads to increased shedding. Objectives To investigate whether loss of platelet receptors occurs in vivo, and the relationship with acquired von Willebrand syndrome (AVWS). Methods Platelet counts, coagulation tests and von Willebrand factor (VWF) analyses were performed on samples from 21 continuous flow VAD (CF-VAD), 20 ECMO, 12 heart failure and seven aortic stenosis patients. Levels of platelet receptors were measured by flow cytometry or ELISA. Results The loss of high molecular weight VWF multimers was observed in 18 of 19 CF-VAD and 14 of 20 ECMO patients, consistent with AVWS. Platelet receptor shedding was demonstrated by elevated soluble glycoprotein (GP) VI levels in plasma and significantly reduced surface GPIbα and GPVI levels in CF-VAD and ECMO patients as compared with healthy donors. Platelet receptor levels were also significantly reduced in heart failure patients. Conclusions These data link AVWS and increased platelet receptor shedding in patients with CF-VADs or ECMO for the first time. Loss of the platelet surface receptors GPIbα and GPVI in heart failure, CF-VAD and ECMO patients may contribute to ablated platelet adhesion/activation, and limit thrombus formation under high/pathologic shear conditions. © 2016 International Society on Thrombosis and Haemostasis.

High passage MIN6 cells have impaired insulin secretion with impaired glucose and lipid oxidation.

Directory of Open Access Journals (Sweden)

Kim Cheng

Full Text Available Type 2 diabetes is a metabolic disorder characterized by the inability of beta-cells to secrete enough insulin to maintain glucose homeostasis. MIN6 cells secrete insulin in response to glucose and other secretagogues, but high passage (HP MIN6 cells lose their ability to secrete insulin in response to glucose. We hypothesized that metabolism of glucose and lipids were defective in HP MIN6 cells causing impaired glucose stimulated insulin secretion (GSIS. HP MIN6 cells had no first phase and impaired second phase GSIS indicative of global functional impairment. This was coupled with a markedly reduced ATP content at basal and glucose stimulated states. Glucose uptake and oxidation were higher at basal glucose but ATP content failed to increase with glucose. HP MIN6 cells had decreased basal lipid oxidation. This was accompanied by reduced expressions of Glut1, Gck, Pfk, Srebp1c, Ucp2, Sirt3, Nampt. MIN6 cells represent an important model of beta cells which, as passage numbers increased lost first phase but retained partial second phase GSIS, similar to patients early in type 2 diabetes onset. We believe a number of gene expression changes occurred to produce this defect, with emphasis on Sirt3 and Nampt, two genes that have been implicated in maintenance of glucose homeostasis.

Alternative protein secretion: The Mam1 ABC transporter supports secretion of M-factor linked GFP in fission yeast

International Nuclear Information System (INIS)

Kjaerulff, Soren; Mueller, Sven; Jensen, Martin Roland

2005-01-01

To examine whether the fission yeast Mam1 ABC transporter can be used for secretion of heterologous proteins, thereby bypassing the classical secretion pathway, we have analyzed chimeric forms of the M-factor precursor. It was demonstrated that GFP can be exported when fused to both the amino-terminal prosequence from mfm1 and a CaaX motif. This secretion was dependent on the Mam1 transporter and not the classical secretion pathway. The secretion efficiency of GFP, however, was relatively low and most of the reporter protein was trapped in the vacuolar membranes. Our findings suggest that the Mam1 ABC protein is a promiscuous peptide transporter that can accommodate globular proteins of a relatively large size. Furthermore, our results help in defining the sequences required for processing and secretion of natural M-factor

29 CFR 401.11 - Secret ballot.

Science.gov (United States)

2010-07-01

... 29 Labor 2 2010-07-01 2010-07-01 false Secret ballot. 401.11 Section 401.11 Labor Regulations Relating to Labor OFFICE OF LABOR-MANAGEMENT STANDARDS, DEPARTMENT OF LABOR LABOR-MANAGEMENT STANDARDS MEANING OF TERMS USED IN THIS SUBCHAPTER § 401.11 Secret ballot. Secret ballot means the expression by...

PKCalpha regulates platelet granule secretion and thrombus formation in mice.

Science.gov (United States)

Konopatskaya, Olga; Gilio, Karen; Harper, Matthew T; Zhao, Yan; Cosemans, Judith M E M; Karim, Zubair A; Whiteheart, Sidney W; Molkentin, Jeffery D; Verkade, Paul; Watson, Steve P; Heemskerk, Johan W M; Poole, Alastair W

2009-02-01

Platelets are central players in atherothrombosis development in coronary artery disease. The PKC family provides important intracellular mechanisms for regulating platelet activity, and platelets express several members of this family, including the classical isoforms PKCalpha and PKCbeta and novel isoforms PKCdelta and PKCtheta. Here, we used a genetic approach to definitively demonstrate the role played by PKCalpha in regulating thrombus formation and platelet function. Thrombus formation in vivo was attenuated in Prkca-/- mice, and PKCalpha was required for thrombus formation in vitro, although this PKC isoform did not regulate platelet adhesion to collagen. The ablation of in vitro thrombus formation in Prkca-/- platelets was rescued by the addition of ADP, consistent with the key mechanistic finding that dense-granule biogenesis and secretion depend upon PKCalpha expression. Furthermore, defective platelet aggregation in response to either collagen-related peptide or thrombin could be overcome by an increase in agonist concentration. Evidence of overt bleeding, including gastrointestinal and tail bleeding, was not seen in Prkca-/- mice. In summary, the effects of PKCalpha ablation on thrombus formation and granule secretion may implicate PKCalpha as a drug target for antithrombotic therapy.

Synthesis of Structures Related to Antifreeze Glycoproteins

OpenAIRE

Fyrner, Timmy

2005-01-01

In this thesis, synthesis of structures related to antifreeze glycoproteins (AFGPs) are presented. Synthetic routes to a protected carbohydrate derivative, 2,3,4,6-tetra-O-benzyl-β-galactopyranosyl-(1→3)-2-deoxy-2-azido-4,6-di-O-benzyl-β-D-thio-1-galactopyranoside, and a tBu-Ala-Thr-Ala-Fmoc tripeptide, are described. These compounds are meant to be used in the assembly of AFGPs and analogues thereof. A Gal-GlcN disaccharide was synthesized via glycosylation between the donor, bromo-2-O-benzo...

Virion Glycoprotein-Mediated Immune Evasion by Human Cytomegalovirus: a Sticky Virus Makes a Slick Getaway

Science.gov (United States)

Gardner, Thomas J.

2016-01-01

SUMMARY The prototypic herpesvirus human cytomegalovirus (CMV) exhibits the extraordinary ability to establish latency and maintain a chronic infection throughout the life of its human host. This is even more remarkable considering the robust adaptive immune response elicited by infection and reactivation from latency. In addition to the ability of CMV to exist in a quiescent latent state, its persistence is enabled by a large repertoire of viral proteins that subvert immune defense mechanisms, such as NK cell activation and major histocompatibility complex antigen presentation, within the cell. However, dissemination outside the cell presents a unique existential challenge to the CMV virion, which is studded with antigenic glycoprotein complexes targeted by a potent neutralizing antibody response. The CMV virion envelope proteins, which are critical mediators of cell attachment and entry, possess various characteristics that can mitigate the humoral immune response and prevent viral clearance. Here we review the CMV glycoprotein complexes crucial for cell attachment and entry and propose inherent properties of these proteins involved in evading the CMV humoral immune response. These include viral glycoprotein polymorphism, epitope competition, Fc receptor-mediated endocytosis, glycan shielding, and cell-to-cell spread. The consequences of CMV virion glycoprotein-mediated immune evasion have a major impact on persistence of the virus in the population, and a comprehensive understanding of these evasion strategies will assist in designing effective CMV biologics and vaccines to limit CMV-associated disease. PMID:27307580

Profiling of Concanavalin A-Binding Glycoproteins in Human Hepatic Stellate Cells Activated with Transforming Growth Factor-β1

Directory of Open Access Journals (Sweden)

Yannan Qin

2014-11-01

Full Text Available Glycoproteins play important roles in maintaining normal cell functions depending on their glycosylations. Our previous study indicated that the abundance of glycoproteins recognized by concanavalin A (ConA was increased in human hepatic stellate cells (HSCs following activation by transforming growth factor-β1 (TGF-β1; however, little is known about the ConA-binding glycoproteins (CBGs of HSCs. In this study, we employed a targeted glycoproteomics approach using lectin-magnetic particle conjugate-based liquid chromatography-tandem mass spectrometry to compare CBG profiles between LX-2 HSCs with and without activation by TGF-β1, with the aim of discovering novel CBGs and determining their possible roles in activated HSCs. A total of 54 and 77 proteins were identified in the quiescent and activated LX-2 cells, respectively. Of the proteins identified, 14.3% were glycoproteins and 73.3% were novel potential glycoproteins. Molecules involved in protein processing in the endoplasmic reticulum (e.g., calreticulin and calcium signaling (e.g., 1-phosphatidylinositol-4,5-bisphosphate phosphodiesterase β-2 [PLCB2] were specifically identified in activated LX-2 cells. Additionally, PLCB2 expression was upregulated in the cytoplasm of the activated LX-2 cells, as well as in the hepatocytes and sinusoidal cells of liver cirrhosis tissues. In conclusion, the results of this study may aid future investigations to find new molecular mechanisms involved in HSC activation and antifibrotic therapeutic targets.

Complement inhibition enables tumor delivery of LCMV glycoprotein pseudotyped viruses in the presence of antiviral antibodies

Directory of Open Access Journals (Sweden)

Laura Evgin

2016-01-01

Full Text Available The systemic delivery of therapeutic viruses, such as oncolytic viruses or vaccines, is limited by the generation of neutralizing antibodies. While pseudotyping of rhabdoviruses with the lymphocytic choriomeningitis virus glycoprotein has previously allowed for multiple rounds of delivery in mice, this strategy has not translated to other animal models. For the first time, we provide experimental evidence that antibodies generated against the lymphocytic choriomeningitis virus glycoprotein mediate robust complement-dependent viral neutralization via activation of the classical pathway. We show that this phenotype can be capitalized upon to deliver maraba virus pseudotyped with the lymphocytic choriomeningitis virus glycoprotein in a Fischer rat model in the face of neutralizing antibody through the use of complement modulators. This finding changes the understanding of the humoral immune response to arenaviruses, and also describes methodology to deliver viral vectors to their therapeutic sites of action without the interference of neutralizing antibody.

29 CFR 1202.4 - Secret ballot.

Science.gov (United States)

2010-07-01

... 29 Labor 4 2010-07-01 2010-07-01 false Secret ballot. 1202.4 Section 1202.4 Labor Regulations Relating to Labor (Continued) NATIONAL MEDIATION BOARD RULES OF PROCEDURE § 1202.4 Secret ballot. In conducting such investigation, the Board is authorized to take a secret ballot of the employees involved, or...

Primary cilia utilize glycoprotein-dependent adhesion mechanisms to stabilize long-lasting cilia-cilia contacts

Directory of Open Access Journals (Sweden)

Ott Carolyn

2012-04-01

cilia detect features of the extracellular space, not just as passive antennae, but also through direct physical contact. We present a model for the cycle of glycoprotein-dependent contact formation, maintenance, and termination, and discuss the implications for potential physiological functions of cilia-cilia contacts.

The Secret of Future Victories

Science.gov (United States)

1992-02-01

Copy S of 320 copies AD--A25 0 718 IDA PAPER P-265 3 THE SECRET OF FUTURE VICTORIES Paul F. Gormnan General, USA (Retired) DTIC 05M February 1992 NAY...TYPE AND DATES COVERED IFebruary 1992 Final--June 1991-January 1992 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS The Secret of Future Victories C -MDA...8 2N0-102 IDA PAPER P-2653 THE SECRET OF FUTURE VICTORIES Paul F. Gorman General. LUSA (Retired) February 1992 Approved for public release

Structural and functional analysis of bovine herpesvirus 1 minor glycoproteins

NARCIS (Netherlands)

Baranowski, E.; Keil, G.; Lyaku, J.; Rijsewijk, F.A.M.; Oirschot, van J.T.; Pastoret, P.P.; Thiry, E.

1996-01-01

This paper focuses on the structure and functions of bovine herpesvirus 1 minor glycoproteins gH, gE, gG and gp42. It reviews the progress which has been made in their identification and characterization, in the study of their temporal expression and processing in infected cells, and finally in the

The effect of imiquimod on taste bud calcium transients and transmitter secretion

Science.gov (United States)

Wu, Sandy Y

2016-01-01

Background and Purpose Imiquimod is an immunomodulator approved for the treatment of basal cell carcinoma and has adverse side effects, including taste disturbances. Paracrine transmission, representing cell–cell communication within taste buds, has the potential to shape the final signals that taste buds transmit to the brain. Here, we tested the underlying assumption that imiquimod modifies taste transmitter secretion in taste buds of mice. Experimental Approach Taste buds were isolated from C57BL/6J mice. The effects of imiquimod on transmitter release in taste buds were measured using calcium imaging with cellular biosensors, and examining the net effect of imiquimod on taste‐evoked ATP secretion from mouse taste buds. Key Results Up to 72% of presynaptic (Type III) taste cells responded to 100 μM imiquimod with an increase in intracellular Ca2+ concentrations. These Ca2 + responses were inhibited by thapsigargin, an inhibitor of the sarco/endoplasmic reticulum Ca2 +‐ATPase, and by U73122, a PLC inhibitor, suggesting that the Ca2 + mobilization elicited by imiquimod was dependent on release from internal Ca2 + stores. Moreover, combining studies of Ca2 + imaging with cellular biosensors showed that imiquimod evoked secretion of 5‐HT, which then provided negative feedback onto receptor (Type II) cells to reduce taste‐evoked ATP secretion. Conclusion and Implications Our results provide evidence that there is a subset of taste cells equipped with a range of intracellular mechanisms that respond to imiquimod. The findings are also consistent with a role of imiquimod as an immune response modifier, which shapes peripheral taste responses via 5‐HT signalling. PMID:27464850

Current Therapies That Modify Glucagon Secretion

DEFF Research Database (Denmark)

Grøndahl, Magnus F.; Keating, Damien J.; Vilsbøll, Tina

2017-01-01

and provide insights into how antidiabetic drugs influence glucagon secretion as well as a perspective on the future of glucagon-targeting drugs. Recent Findings: Several older as well as recent investigations have evaluated the effect of antidiabetic agents on glucagon secretion to understand how glucagon...... may be involved in the drugs’ efficacy and safety profiles. Based on these findings, modulation of glucagon secretion seems to play a hitherto underestimated role in the efficacy and safety of several glucose-lowering drugs. Summary: Numerous drugs currently available to diabetologists are capable...... of altering glucagon secretion: metformin, sulfonylurea compounds, insulin, glucagon-like peptide-1 receptor agonists, dipeptidyl peptidase-4 inhibitors, sodium-glucose cotransporter 2 inhibitors and amylin mimetics. Their diverse effects on glucagon secretion are of importance for their individual efficacy...

Characterization of a secreted Chlamydia protease

DEFF Research Database (Denmark)

Shaw, A.C.; Vandahl, B.B.; Larsen, M.R.

2002-01-01

Chlamydiae are obligate intracellular bacteria that are important human pathogens. The Chlamydia genomes contain orthologues to secretion apparatus proteins from other intracellular bacteria, but only a few secreted proteins have been identified. Most likely, effector proteins are secreted in order...... to promote infection. Effector proteins cannot be identified by motif or similarity searches. As a new strategy for identification of secreted proteins we have compared 2D-PAGE profiles of [35S]-labelled Chlamydia proteins from whole lysates of infected cells to 2D-PAGE profiles of proteins from purified...... Chlamydia. Several secretion candidates from Chlamydia trachomatis D and Chlamydia pneumoniae were detected by this method. Two protein spots were identified among the candidates. These represent fragments of the 'chlamydial protease- or proteasome-like activity factor' (CPAF) and were clearly present in 2D...

EFFECTS OF SECRETABLE PLACENTAL FACTORS UPON SECRETION OF CYTOKINES BY THP-1 MONOCYTE-LIKE CELLS

Directory of Open Access Journals (Sweden)

Ya. S. Onokhina

2013-01-01

Full Text Available Abstract. Мonocytes in feto-placental circulation are exposed to factors secreted by placental tissue. These factors influence monocyte functions in pregnancy. In present study, an in vitro model (monocyte-like THP-1 cells was used for assessing effects of soluble placental factors obtained from women with physiological pregnancies, or preeclampsia cases. The following effects of placental factors were revealed: increased secretion of VEGF by THP-1 cells along with decreased secretion of IL-6, IL-8 and MCP-1 under the influence of placental factors from the I. trimester of pregnancy in comparison with III. trimester. Secretion of IL-6 and MCP-1 by THP-1 cells was increased, and secretion of soluble TNFRII was decreased upon co-cultivation with soluble placental factors from the women with preeclampsia, as compared with placental products from physiological pregnancies.The work is supported by grants ГК № 02.740.11.0711 from Ministry of Education and Science, and НШ-3594.2010.7 grant from the President of Russian Federation.

Bile-induced secretion of glucagon-like peptide-1: pathophysiological implications in type 2 diabetes?

DEFF Research Database (Denmark)

Knop, Filip Krag

2010-01-01

During the last decades it has become clear that bile acids not only act as simple fat solubilizers, but additionally represent complex hormonal metabolic integrators. Bile acids activate both nuclear receptors (controlling transcription of genes involved in for example bile acid, cholesterol......, and glucose metabolism) and the cell surface G protein-coupled receptor TGR5 (modulating energy expenditure in brown fat and muscle cells). It has been shown that TGR5 is expressed in enteroendocrine L cells, which secrete the potent glucose-lowering incretin hormone glucagon-like peptide-1 (GLP-1). Recently...

5 CFR 2421.15 - Secret ballot.

Science.gov (United States)

2010-01-01

... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Secret ballot. 2421.15 Section 2421.15... FEDERAL LABOR RELATIONS AUTHORITY MEANING OF TERMS AS USED IN THIS SUBCHAPTER § 2421.15 Secret ballot. Secret ballot means the expression by ballot, voting machine or otherwise, but in no event by proxy, of a...

29 CFR 452.97 - Secret ballot.

Science.gov (United States)

2010-07-01

... 29 Labor 2 2010-07-01 2010-07-01 false Secret ballot. 452.97 Section 452.97 Labor Regulations... OF 1959 Election Procedures; Rights of Members § 452.97 Secret ballot. (a) A prime requisite of elections regulated by title IV is that they be held by secret ballot among the members or in appropriate...

The glycoprotein genes and gene junctions of the fish rhabdoviruses spring viremia of carp virus and hirame rhabdovirus: Analysis of relationships with other rhabdoviruses

Science.gov (United States)

Bjorklund, H.V.; Higman, K.H.; Kurath, G.

1996-01-01

The nucleotide sequences of the glycoprotein genes and all of the internal gene junctions of the fish pathogenic rhabdoviruses spring viremia of carp virus (SVCV) and hirame rhabdovirus (HIRRV) have been determined from cDNA clones generated from viral genomic RNA. The SVCV glycoprotein gene sequence is 1588 nucleotides (nt) long and encodes a 509 amino acid (aa) protein. The HIRRV glycoprotein gene sequence comprises 1612 nt, coding for a 508 aa protein. In sequence comparisons of 15 rhabdovirus glycoproteins, the SVCV glycoprotein gene showed the highest amino acid sequence identity (31.2–33.2%) with vesicular stomatitis New Jersey virus (VSNJV), Chandipura virus (CHPV) and vesicular stomatitis Indiana virus (VSIV). The HIRRV glycoprotein gene showed a very high amino acid sequence identity (74.3%) with the glycoprotein gene of another fish pathogenic rhabdovirus, infectious hematopoietic necrosis virus (IHNV), but no significant similarity with glycoproteins of VSIV or rabies virus (RABV). In phylogenetic analyses SVCV was grouped consistently with VSIV, VSNJV and CHPV in the Vesiculovirus genus of Rhabdoviridae. The fish rhabdoviruses HIRRV, IHNV and viral hemorrhagic septicemia virus (VHSV) showed close relationships with each other, but only very distant relationships with mammalian rhabdoviruses. The gene junctions are highly conserved between SVCV and VSIV, well conserved between IHNV and HIRRV, but not conserved between HIRRV/IHNV and RABV. Based on the combined results we suggest that the fish lyssa-type rhabdoviruses HIRRV, IHNV and VHSV may be grouped in their own genus within the family Rhabdoviridae. Aquarhabdovirus has been proposed for the name of this new genus.

Galectin-3 induces clustering of CD147 and integrin-β1 transmembrane glycoprotein receptors on the RPE cell surface.

Directory of Open Access Journals (Sweden)

Claudia S Priglinger

Full Text Available Proliferative vitreoretinopathy (PVR is a blinding disease frequently occurring after retinal detachment surgery. Adhesion, migration and matrix remodeling of dedifferentiated retinal pigment epithelial (RPE cells characterize the onset of the disease. Treatment options are still restrained and identification of factors responsible for the abnormal behavior of the RPE cells will facilitate the development of novel therapeutics. Galectin-3, a carbohydrate-binding protein, was previously found to inhibit attachment and spreading of retinal pigment epithelial cells, and thus bares the potential to counteract PVR-associated cellular events. However, the identities of the corresponding cell surface glycoprotein receptor proteins on RPE cells are not known. Here we characterize RPE-specific Gal-3 containing glycoprotein complexes using a proteomic approach. Integrin-β1, integrin-α3 and CD147/EMMPRIN, a transmembrane glycoprotein implicated in regulating matrix metalloproteinase induction, were identified as potential Gal-3 interactors on RPE cell surfaces. In reciprocal immunoprecipitation experiments we confirmed that Gal-3 associated with CD147 and integrin-β1, but not with integrin-α3. Additionally, association of Gal-3 with CD147 and integrin-β1 was observed in co-localization analyses, while integrin-α3 only partially co-localized with Gal-3. Blocking of CD147 and integrin-β1 on RPE cell surfaces inhibited binding of Gal-3, whereas blocking of integrin-α3 failed to do so, suggesting that integrin-α3 is rather an indirect interactor. Importantly, Gal-3 binding promoted pronounced clustering and co-localization of CD147 and integrin-β1, with only partial association of integrin-α3. Finally, we show that RPE derived CD147 and integrin-β1, but not integrin-α3, carry predominantly β-1,6-N-actyl-D-glucosamine-branched glycans, which are high-affinity ligands for Gal-3. We conclude from these data that extracellular Gal-3 triggers

Galectin-3 Induces Clustering of CD147 and Integrin-β1 Transmembrane Glycoprotein Receptors on the RPE Cell Surface

Science.gov (United States)

Priglinger, Claudia S.; Szober, Christoph M.; Priglinger, Siegfried G.; Merl, Juliane; Euler, Kerstin N.; Kernt, Marcus; Gondi, Gabor; Behler, Jennifer; Geerlof, Arie; Kampik, Anselm; Ueffing, Marius; Hauck, Stefanie M.

2013-01-01

Proliferative vitreoretinopathy (PVR) is a blinding disease frequently occurring after retinal detachment surgery. Adhesion, migration and matrix remodeling of dedifferentiated retinal pigment epithelial (RPE) cells characterize the onset of the disease. Treatment options are still restrained and identification of factors responsible for the abnormal behavior of the RPE cells will facilitate the development of novel therapeutics. Galectin-3, a carbohydrate-binding protein, was previously found to inhibit attachment and spreading of retinal pigment epithelial cells, and thus bares the potential to counteract PVR-associated cellular events. However, the identities of the corresponding cell surface glycoprotein receptor proteins on RPE cells are not known. Here we characterize RPE-specific Gal-3 containing glycoprotein complexes using a proteomic approach. Integrin-β1, integrin-α3 and CD147/EMMPRIN, a transmembrane glycoprotein implicated in regulating matrix metalloproteinase induction, were identified as potential Gal-3 interactors on RPE cell surfaces. In reciprocal immunoprecipitation experiments we confirmed that Gal-3 associated with CD147 and integrin-β1, but not with integrin-α3. Additionally, association of Gal-3 with CD147 and integrin-β1 was observed in co-localization analyses, while integrin-α3 only partially co-localized with Gal-3. Blocking of CD147 and integrin-β1 on RPE cell surfaces inhibited binding of Gal-3, whereas blocking of integrin-α3 failed to do so, suggesting that integrin-α3 is rather an indirect interactor. Importantly, Gal-3 binding promoted pronounced clustering and co-localization of CD147 and integrin-β1, with only partial association of integrin-α3. Finally, we show that RPE derived CD147 and integrin-β1, but not integrin-α3, carry predominantly β-1,6-N-actyl-D-glucosamine-branched glycans, which are high-affinity ligands for Gal-3. We conclude from these data that extracellular Gal-3 triggers clustering of CD147 and

Secretive eating among youth with overweight or obesity.

Science.gov (United States)

Kass, Andrea E; Wilfley, Denise E; Eddy, Kamryn T; Boutelle, Kerri N; Zucker, Nancy; Peterson, Carol B; Le Grange, Daniel; Celio-Doyle, Angela; Goldschmidt, Andrea B

2017-07-01

Secretive eating, characterized by eating privately to conceal being seen, may reflect eating- and/or body-related shame, be associated with depression, and correlate with binge eating, which predicts weight gain and eating disorder onset. Increasing understanding of secretive eating in youth may improve weight status and reduce eating disorder risk. This study evaluated the prevalence and correlates of secretive eating in youth with overweight or obesity. Youth (N = 577) presented to five research/clinical institutions. Using a cross-sectional design, secretive eating was evaluated in relation to eating-related and general psychopathology via linear and logistic regression analyses. Secretive eating was endorsed by 111 youth, who were, on average, older than youth who denied secretive eating (mean age = 12.07 ± 2.83 versus 10.97 ± 2.31). Controlling for study site and age, youth who endorsed secretive eating had higher eating-related psychopathology and were more likely to endorse loss of control eating and purging than their counterparts who did not endorse secretive eating. Groups did not differ in excessive exercise or behavioral problems. Dietary restraint and purging were elevated among adolescents (≥13y) but not children (<13y) who endorsed secretive eating; depression was elevated among children, but not adolescents, who endorsed secretive eating. Secretive eating may portend heightened risk for eating disorders, and correlates of secretive eating may differ across pediatric development. Screening for secretive eating may inform identification of problematic eating behaviors, and understanding factors motivating secretive eating may improve intervention tailoring. Copyright © 2017 Elsevier Ltd. All rights reserved.

Gene targeting implicates Cdc42 GTPase in GPVI and non-GPVI mediated platelet filopodia formation, secretion and aggregation.

Directory of Open Access Journals (Sweden)

Huzoor Akbar

Full Text Available Cdc42 and Rac1, members of the Rho family of small GTPases, play critical roles in actin cytoskeleton regulation. We have shown previously that Rac1 is involved in regulation of platelet secretion and aggregation. However, the role of Cdc42 in platelet activation remains controversial. This study was undertaken to better understand the role of Cdc42 in platelet activation.We utilized the Mx-cre;Cdc42(lox/lox inducible mice with transient Cdc42 deletion to investigate the involvement of Cdc42 in platelet function. The Cdc42-deficient mice exhibited a significantly reduced platelet count than the matching Cdc42(+/+ mice. Platelets isolated from Cdc42(-/-, as compared to Cdc42(+/+, mice exhibited (a diminished phosphorylation of PAK1/2, an effector molecule of Cdc42, (b inhibition of filopodia formation on immobilized CRP or fibrinogen, (c inhibition of CRP- or thrombin-induced secretion of ATP and release of P-selectin, (d inhibition of CRP, collagen or thrombin induced platelet aggregation, and (e minimal phosphorylation of Akt upon stimulation with CRP or thrombin. The bleeding times were significantly prolonged in Cdc42(-/- mice compared with Cdc42(+/+ mice.Our data demonstrate that Cdc42 is required for platelet filopodia formation, secretion and aggregation and therefore plays a critical role in platelet mediated hemostasis and thrombosis.

Long-term outcomes of surgery and radiotherapy for secreting and non-secreting pituitary adenoma

International Nuclear Information System (INIS)

Kim, Mi Young; Kim, Jin Hee; Oh, Young Kee; Kim, El

2016-01-01

To investigate treatment outcome and long term complication after surgery and radiotherapy (RT) for pituitary adenoma. From 1990 to 2009, 73 patients with surgery and RT for pituitary adenoma were analyzed in this study. Median age was 51 years (range, 25 to 71 years). Median tumor size was 3 cm (range, 1 to 5 cm) with suprasellar (n = 21), cavernous sinus extension (n = 14) or both (n = 5). Hormone secreting tumor was diagnosed in 29 patients; 16 patients with prolactin, 12 patients with growth hormone, and 1 patient with adrenocorticotrophic hormone. Impairment of visual acuity or visual field was presented in 33 patients at first diagnosis. Most patients (n = 64) received RT as postoperative adjuvant setting. Median RT dose was 45 Gy (range, 45 to 59.4 Gy). Median follow-up duration was 8 years (range, 3 to 22 years). In secreting tumors, hormone normalization rate was 55% (16 of 29 patients). For 25 patients with evaluable visual field and visual acuity test, 21 patients (84%) showed improvement of visual disturbance after treatment. The 10-year tumor control rate for non-secreting and secreting adenoma was 100% and 58%, respectively (p < 0.001). Progression free survival rate at 10 years was 98%. Only 1 patient experienced endocrinological recurrence. Following surgery, 60% (n = 44) suffered from pituitary function deficit. Late complication associated with RT was only 1 patient, who developed cataract. Surgery and RT are very effective and safe in hormonal and tumor growth control for secreting and non-secreting pituitary adenoma

Long-term outcomes of surgery and radiotherapy for secreting and non-secreting pituitary adenoma

Energy Technology Data Exchange (ETDEWEB)

Kim, Mi Young; Kim, Jin Hee; Oh, Young Kee; Kim, El [Dongsan Medical Center, Keimyung University School of Medicine, Daegu (Korea, Republic of)

2016-06-15

To investigate treatment outcome and long term complication after surgery and radiotherapy (RT) for pituitary adenoma. From 1990 to 2009, 73 patients with surgery and RT for pituitary adenoma were analyzed in this study. Median age was 51 years (range, 25 to 71 years). Median tumor size was 3 cm (range, 1 to 5 cm) with suprasellar (n = 21), cavernous sinus extension (n = 14) or both (n = 5). Hormone secreting tumor was diagnosed in 29 patients; 16 patients with prolactin, 12 patients with growth hormone, and 1 patient with adrenocorticotrophic hormone. Impairment of visual acuity or visual field was presented in 33 patients at first diagnosis. Most patients (n = 64) received RT as postoperative adjuvant setting. Median RT dose was 45 Gy (range, 45 to 59.4 Gy). Median follow-up duration was 8 years (range, 3 to 22 years). In secreting tumors, hormone normalization rate was 55% (16 of 29 patients). For 25 patients with evaluable visual field and visual acuity test, 21 patients (84%) showed improvement of visual disturbance after treatment. The 10-year tumor control rate for non-secreting and secreting adenoma was 100% and 58%, respectively (p < 0.001). Progression free survival rate at 10 years was 98%. Only 1 patient experienced endocrinological recurrence. Following surgery, 60% (n = 44) suffered from pituitary function deficit. Late complication associated with RT was only 1 patient, who developed cataract. Surgery and RT are very effective and safe in hormonal and tumor growth control for secreting and non-secreting pituitary adenoma.

P-glycoprotein interaction with risperidone and 9-OH-risperidone studied in vitro, in knock-out mice and in drug-drug interaction experiments

DEFF Research Database (Denmark)

Ejsing, Thomas B.; Pedersen, Anne D.; Linnet, Kristian

2005-01-01

P-glycoprotein, risperidone, nortriptyline, cyclosporine A, drug-drug interaction, blood-brain barrier, knock-out mice......P-glycoprotein, risperidone, nortriptyline, cyclosporine A, drug-drug interaction, blood-brain barrier, knock-out mice...

Extracellular secretion of a recombinant therapeutic peptide by Bacillus halodurans utilizing a modified flagellin type III secretion system

CSIR Research Space (South Africa)

Berger, E

2011-08-01

Full Text Available further 3.5-fold increase in the secretion of recombinant peptide fusions. Conclusions: The type III flagellar secretion system of B. halodurans has been shown to successfully secrete a therapeutic peptide as a heterologous flagellin fusion. Improvements...

Tumor specific glycoproteins and method for detecting tumorigenic cancers

International Nuclear Information System (INIS)

Davidson, E.A.; Bolmer, S.D.

1981-01-01

The detection of tumour specific glycoproteins (TSGP) in human sera often indicates the presence of a malignant tumour in a patient. The distinguishing characteristics of TSGP isolated from the blood sera of cancer patients are described in detail together with methods of TSGP isolation and purification. Details are also given of radioimmunoassay techniques capable of detecting very low levels of serum TSGP with high specificity. (U.K.)

Pituitary-hormone secretion by thyrotropinomas

NARCIS (Netherlands)

Roelfsema, Ferdinand; Kok, Simon; Kok, Petra; Pereira, Alberto M.; Biermasz, Nienke R.; Smit, Jan W.; Frolich, Marijke; Keenan, Daniel M.; Veldhuis, Johannes D.; Romijn, Johannes A.

2009-01-01

Hormone secretion by somatotropinomas, corticotropinomas and prolactinomas exhibits increased pulse frequency, basal and pulsatile secretion, accompanied by greater disorderliness. Increased concentrations of growth hormone (GH) or prolactin (PRL) are observed in about 30% of thyrotropinomas leading

Cardiac myocyte follistatin-like 1 functions to attenuate hypertrophy following pressure overload

NARCIS (Netherlands)

Shimano, Masayuki; Ouchi, Noriyuki; Nakamura, Kazuto; van Wijk, Bram; Ohashi, Koji; Asaumi, Yasuhide; Higuchi, Akiko; Pimentel, David R.; Sam, Flora; Murohara, Toyoaki; van den Hoff, Maurice J. B.; Walsh, Kenneth

2011-01-01

Factors secreted by the heart, referred to as "cardiokines," have diverse actions in the maintenance of cardiac homeostasis and remodeling. Follistatin-like 1 (Fstl1) is a secreted glycoprotein expressed in the adult heart and is induced in response to injurious conditions that promote myocardial

Poverty and Cultism in Our Contemporary Society: Implications for ...

African Journals Online (AJOL)

DR Nneka

activities whose beliefs are typically secret, esoteric and individualistic. The Lexicon ..... that are self-employed and rely on electricity power have to pay heavily to do their ... The implication is that this bodily harm may result in untimely death ... that would favour job creation like the establishment of Small and Medium Scale.

Internalization and Axonal Transport of the HIV Glycoprotein gp120

Science.gov (United States)

Berth, Sarah; Caicedo, Hector Hugo; Sarma, Tulika; Morfini, Gerardo

2015-01-01

The HIV glycoprotein gp120, a neurotoxic HIV glycoprotein that is overproduced and shed by HIV-infected macrophages, is associated with neurological complications of HIV such as distal sensory polyneuropathy, but interactions of gp120 in the peripheral nervous system remain to be characterized. Here, we demonstrate internalization of extracellular gp120 in a manner partially independent of binding to its coreceptor CXCR4 by F11 neuroblastoma cells and cultured dorsal root ganglion neurons. Immunocytochemical and pharmacological experiments indicate that gp120 does not undergo trafficking through the endolysosomal pathway. Instead, gp120 is mainly internalized through lipid rafts in a cholesterol-dependent manner, with a minor fraction being internalized by fluid phase pinocytosis. Experiments using compartmentalized microfluidic chambers further indicate that, after internalization, endocytosed gp120 selectively undergoes retrograde but not anterograde axonal transport from axons to neuronal cell bodies. Collectively, these studies illuminate mechanisms of gp120 internalization and axonal transport in peripheral nervous system neurons, providing a novel framework for mechanisms for gp120 neurotoxicity. PMID:25636314

Normal and abnormal secretion by haemopoietic cells

Science.gov (United States)

STINCHCOMBE, JANE C; GRIFFITHS, GILLIAN M

2001-01-01

The secretory lysosomes found in haemopoietic cells provide a very efficient mechanism for delivering the effector proteins of many immune cells in response to antigen recognition. Although secretion shows some similarities to the secretion of specialized granules in other secretory cell types, some aspects of secretory lysosome release appear to be unique to melanocytes and cells of the haemopoietic lineage. Mast cells and platelets have provided excellent models for studying secretion, but recent advances in characterizing the immunological synapse allow a very fine dissection of the secretory process in T lymphocytes. These studies show that secretory lysosomes are secreted from the centre of the talin ring at the synapse. Proper secretion requires a series of Rab and cytoskeletal elements which play critical roles in the specialized secretion of lysosomes in haemopoietic cells. PMID:11380687

Characterization of a novel brain barrier ex vivo insect-based P-glycoprotein screening model

DEFF Research Database (Denmark)

Andersson, O.; Badisco, L.; Hansen, A. H.

2014-01-01

In earlier studies insects were proposed as suitable models for vertebrate blood–brain barrier (BBB) permeability prediction and useful in early drug discovery. Here we provide transcriptome and functional data demonstrating the presence of a P-glycoprotein (Pgp) efflux transporter in the brain b...... has the potential to act as a robust and convenient model for assessing BBB permeability in early drug discovery.......In earlier studies insects were proposed as suitable models for vertebrate blood–brain barrier (BBB) permeability prediction and useful in early drug discovery. Here we provide transcriptome and functional data demonstrating the presence of a P-glycoprotein (Pgp) efflux transporter in the brain...

Stable isotope labeling of glycoprotein expressed in silkworms using immunoglobulin G as a test molecule

Energy Technology Data Exchange (ETDEWEB)

Yagi, Hirokazu [Nagoya City University, Faculty and Graduate School of Pharmaceutical Sciences (Japan); Nakamura, Masatoshi [National Institute of Agrobiological Sciences, Genetic Resources Conservation Research Unit, Genetic Resources Center (Japan); Yokoyama, Jun [Taiyo Nippon Sanso Corporation, Tsukuba Laboratories (Japan); Zhang, Ying; Yamaguchi, Takumi [National Institutes of Natural Sciences, Institute for Molecular Science and Okazaki Institute for Integrative Bioscience (Japan); Kondo, Sachiko [Nagoya City University, Faculty and Graduate School of Pharmaceutical Sciences (Japan); Kobayashi, Jun [Yamaguchi University, Department of Biological and Environmental Sciences, Faculty of Agriculture (Japan); Kato, Tatsuya; Park, Enoch Y. [Shizuoka University, Laboratory of Biotechnology, Research Institute of Green Science and Technology (Japan); Nakazawa, Shiori [Nagoya University, Sugashima Marine Biological Laboratory, Graduate School of Science (Japan); Hashii, Noritaka; Kawasaki, Nana [National Institute of Health Sciences, Division of Biological Chemistry and Biologicals (Japan); Kato, Koichi, E-mail: kkato@phar.nagoya-cu.ac.jp [Nagoya City University, Faculty and Graduate School of Pharmaceutical Sciences (Japan)

2015-06-15

Silkworms serve as promising bioreactors for the production of recombinant proteins, including glycoproteins and membrane proteins, for structural and functional protein analyses. However, lack of methodology for stable isotope labeling has been a major deterrent to using this expression system for nuclear magnetic resonance (NMR) structural biology. Here we developed a metabolic isotope labeling technique using commercially available silkworm larvae. The fifth instar larvae were infected with baculoviruses for co-expression of recombinant human immunoglobulin G (IgG) as a test molecule, with calnexin as a chaperone. They were subsequently reared on an artificial diet containing {sup 15}N-labeled yeast crude protein extract. We harvested 0.1 mg of IgG from larva with a {sup 15}N-enrichment ratio of approximately 80 %. This allowed us to compare NMR spectral data of the Fc fragment cleaved from the silkworm-produced IgG with those of an authentic Fc glycoprotein derived from mammalian cells. Therefore, we successfully demonstrated that our method enables production of isotopically labeled glycoproteins for NMR studies.

P-glycoprotein in autoimmune rheumatic diseases.

Science.gov (United States)

García-Carrasco, M; Mendoza-Pinto, C; Macias Díaz, S; Vera-Recabarren, M; Vázquez de Lara, L; Méndez Martínez, S; Soto-Santillán, P; González-Ramírez, R; Ruiz-Arguelles, A

2015-07-01

P-glycoprotein (Pgp) is a transmembrane protein of 170 kD encoded by the multidrug resistance 1 (MDR-1) gene, localized on chromosome 7. More than 50 polymorphisms of the MDR-1 gene have been described; a subset of these has been shown to play a pathophysiological role in the development of inflammatory bowel disease, femoral head osteonecrosis induced by steroids, lung cancer and renal epithelial tumors. Polymorphisms that have a protective effect on the development of conditions such as Parkinson disease have also been identified. P-glycoprotein belongs to the adenosine triphosphate binding cassette transporter superfamily and its structure comprises a chain of approximately 1280 aminoacid residues with an N-C terminal structure, arranged as 2 homologous halves, each of which has 6 transmembrane segments, with a total of 12 segments with 2 cytoplasmic nucleotide binding domains. Many cytokines like interleukin 2 and tumor necrosis factor alpha increase Pgp expression and activity. Pgp functions as an efflux pump for a variety of toxins in order to protect particular organs and tissues as the central nervous system. Pgp transports a variety of substrates including glucocorticoids while other drugs such as tacrolimus and cyclosporine A act as modulators of this protein. The most widely used method to measure Pgp activity is flow cytometry using naturally fluorescent substrates such as anthracyclines or rhodamine 123. The study of drug resistance and its association to Pgp began with the study of resistance to chemotherapy in the treatment of cancer and antiretroviral therapy for human immunodeficiency virus; however, the role of Pgp in the treatment of systemic lupus erythematosus, rheumatoid arthritis and psoriatic arthritis has been a focus of study lately and has emerged as an important mechanism by which treatment failure occurs. The present review analyzes the role of Pgp in these autoimmune diseases. Copyright © 2015 Elsevier B.V. All rights reserved.

Some Economics of Trade Secret Law

OpenAIRE

David D. Friedman; William M. Landes; Richard A. Posner

1991-01-01

Despite the practical importance of trade secrets to the business community, the law of trade secrets is a neglected orphan in economic analysis. This paper sketches an approach to the economics of trade secret law that connects it more closely both to other areas of intellectual property and to broader issues in the positive economic theory of the common law.

Human intestinal P-glycoprotein activity estimated by the model substrate digoxin

DEFF Research Database (Denmark)

Larsen, U L; Hyldahl Olesen, L; Nyvold, Charlotte Guldborg

2007-01-01

P-glycoprotein (Pgp) plays a part in the intestinal uptake of xenobiotics and has been associated with susceptibility to ulcerative colitis. The aim of this study was to examine Pgp activity in relation to age, gender, medical treatment (rifampicin or ketoconazole) and the multidrug resistance (MDR...

Physiology of bile secretion.

Science.gov (United States)

Esteller, Alejandro

2008-10-07

The formation of bile depends on the structural and functional integrity of the bile-secretory apparatus and its impairment, in different situations, results in the syndrome of cholestasis. The structural bases that permit bile secretion as well as various aspects related with its composition and flow rate in physiological conditions will first be reviewed. Canalicular bile is produced by polarized hepatocytes that hold transporters in their basolateral (sinusoidal) and apical (canalicular) plasma membrane. This review summarizes recent data on the molecular determinants of this primary bile formation. The major function of the biliary tree is modification of canalicular bile by secretory and reabsorptive processes in bile-duct epithelial cells (cholangiocytes) as bile passes through bile ducts. The mechanisms of fluid and solute transport in cholangiocytes will also be discussed. In contrast to hepatocytes where secretion is constant and poorly controlled, cholangiocyte secretion is regulated by hormones and nerves. A short section dedicated to these regulatory mechanisms of bile secretion has been included. The aim of this revision was to set the bases for other reviews in this series that will be devoted to specific issues related with biliary physiology and pathology.

Chicken galectin-1B inhibits Newcastle disease virus adsorption and replication through binding to hemagglutinin-neuraminidase (HN) glycoprotein.

Science.gov (United States)

Sun, Junfeng; Han, Zongxi; Qi, Tianming; Zhao, Ran; Liu, Shengwang

2017-12-08

Galectin-1 is an important immunoregulatory factor and can mediate the host-pathogen interaction via binding glycans on the surface of various viruses. We previously reported that avian respiratory viruses, including lentogenic Newcastle disease virus (NDV), can induce up-regulation of chicken galectin (CG)-1B in the primary target organ. In this study, we investigated whether CG-1B participated in the infectious process of NDV in chickens. We demonstrated that velogenic NDV induced up-regulation of CG-1B in target organs. We also found that CG-1B directly bound to NDV virions and inhibited their hemagglutination activity in vitro We confirmed that CG-1B interacted with NDV hemagglutinin-neuraminidase (HN) glycoprotein, in which the specific G4 N -glycans significantly contributed to the interaction between CG-1B and HN glycoprotein. The presence of extracellular CG-1B, rather than the internalization process, inhibited adsorption of NDV. The interaction between intracellular CG-1B and NDV HN glycoproteins inhibited cell-surface expression of HN glycoprotein and reduced the titer of progeny virus in NDV-infected DF-1 cells. Significantly, the replication of parental and HN glycosylation mutant viruses in CG-1B knockdown and overexpression cells demonstrated that the replication of NDV was correlated with the expression of CG-1B in a specific glycan-dependent manner. Collectively, our results indicate that CG-1B has anti-NDV activity by binding to N -glycans on HN glycoprotein. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Colony stimulating factors and their clinical implication

International Nuclear Information System (INIS)

Asano, Shigetaka

1989-01-01

Granulocytes and macrophage are dependent for their production and/or functional activation in vitro on the presence of a family of glycoproteins. They are generally called colony-stimulating factors (CSFs) because of their capacity to stimulate colony formation in semi-solid cultures, and are currently classified into four distinct subtypes, that is, Multi-CSF, GM-CSF, G-CSF and M-CSF, according to the cell type of colonies formed under their stimulation or their target cell specificity. All of the murine and human CSF subtypes and the genes for them have become available in a purified form and in a large scale, and now allow us to investigate their interactions, the mechanisms for their actions, the cell-cell interactions leading to their production and secretion, and their actions in vivo. Furthermore, the preclinical and/or clinical studies which were carried out using the purified CSFs strongly indicate that human CSFs will be effective strategies for preventing and treating opportunistic bacterial and fungal infection as a major cause of death in granulocytopenic patients. (author)

Unconventional Pathways of Secretion Contribute to Inflammation

Directory of Open Access Journals (Sweden)

Michael J. D. Daniels

2017-01-01

Full Text Available In the conventional pathway of protein secretion, leader sequence-containing proteins leave the cell following processing through the endoplasmic reticulum (ER and Golgi body. However, leaderless proteins also enter the extracellular space through mechanisms collectively known as unconventional secretion. Unconventionally secreted proteins often have vital roles in cell and organism function such as inflammation. Amongst the best-studied inflammatory unconventionally secreted proteins are interleukin (IL-1β, IL-1α, IL-33 and high-mobility group box 1 (HMGB1. In this review we discuss the current understanding of the unconventional secretion of these proteins and highlight future areas of research such as the role of nuclear localisation.

Proton pump inhibitors inhibit pancreatic secretion

DEFF Research Database (Denmark)

Wang, Jing; Barbuskaite, Dagne; Tozzi, Marco

2015-01-01

+/K+-ATPases are expressed and functional in human pancreatic ducts and whether proton pump inhibitors (PPIs) have effect on those. Here we show that the gastric HKα1 and HKβ subunits (ATP4A; ATP4B) and non-gastric HKα2 subunits (ATP12A) of H+/K+-ATPases are expressed in human pancreatic cells. Pumps have similar...... of major ions in secretion follow similar excretory curves in control and PPI treated animals. In addition to HCO3-, pancreas also secretes K+. In conclusion, this study calls for a revision of the basic model for HCO3- secretion. We propose that proton transport is driving secretion, and that in addition...

Hoopoes color their eggs with antimicrobial uropygial secretions

Science.gov (United States)

Soler, Juan J.; Martín-Vivaldi, M.; Peralta-Sánchez, J. M.; Arco, L.; Juárez-García-Pelayo, N.

2014-09-01

Uropygial gland secretions are used as cosmetics by some species of birds to color and enhance properties of feathers and teguments, which may signal individual quality. Uropygial secretions also reach eggshells during incubation and, therefore, may influence the coloration of birds' eggs, a trait that has attracted the attention of evolutionary biologists for more than one century. The color of hoopoe eggs typically changes along incubation, from bluish-gray to greenish-brown. Here, we test experimentally the hypothesis that dark uropygial secretion of females is responsible for such drastic color change. Moreover, since uropygial secretion of hoopoes has antimicrobial properties, we also explore the association between color and antimicrobial activity of the uropygial secretion of females. We found that eggs stayed bluish-gray in nests where female access to the uropygial secretion was experimentally blocked. Furthermore, experimental eggs that were maintained in incubators and manually smeared with uropygial secretion experienced similar color changes that naturally incubated eggs did, while control eggs that were not in contact with the secretions did not experience such color changes. All these results strongly support the hypothesis that female hoopoes use their uropygial gland secretion to color the eggs. Moreover, saturation of the uropygial secretion was associated with antimicrobial activity against Bacillus licheniformis. Given the known antimicrobial potential of uropygial secretions of birds, this finding opens the possibility that in scenarios of sexual selection, hoopoes in particular and birds in general signal antimicrobial properties of their uropygial secretion by mean of changes in egg coloration along incubation.

Substantial excretion of digoxin via the intestinal mucosa and prevention of long-term digoxin accumulation in the brain by the mdr1a P-glycoprotein

NARCIS (Netherlands)

Mayer, U; Wagenaar, E; Beijnen, J.H; Smit, J.W; Meijer, D.K F; van Asperen, J.; Borst, P; Schinkel, A.H

1 We have used mice with a disrupted mdrla P-glycoprotein gene (mdrIa (-/-) mice) to study the role of P-glycoprotein in the pharmacokinetics of digoxin, a model P-glycoprotein substrate. 2 [K-3]-digoxin at a dose of 0.2 mg kg(-1) was administered as a single i.v. or oral bolus injection. We

Identification of active pocket and protein druggability within envelope glycoprotein GP2 from Ebola virus

Directory of Open Access Journals (Sweden)

Beuy Joob

2014-12-01

Full Text Available The drug searching for combating the present outbreak of Ebola virus infection is the urgent activity at present. Finding the new effective drug at present must base on the molecular analysis of the pathogenic virus. The in-depth analysis of the viral protein to find the binding site, active pocket is needed. Here, the authors analyzed the envelope glycoprotein GP2 from Ebola virus. Identification of active pocket and protein druggability within envelope glycoprotein GP2 from Ebola virus was done. According to this assessment, 7 active pockets with varied druggability could be identified.

Conglutinin binds the HIV-1 envelope glycoprotein gp 160 and inhibits its interaction with cell membrane CD4

DEFF Research Database (Denmark)

Andersen, Ove; Sørensen, A M; Svehag, S E

1991-01-01

The highly glycosylated envelope glycoprotein (gp 160) of human immunodeficiency virus (HIV) interacts with the CD4 molecule present on the membrane of CD4+ cells and is involved in the pathobiology of HIV infection. Lectins bind glycoproteins through non-covalent interactions with specific hexose...... residues. The mammalian C-type lectin bovine conglutinin was examined for its ability to interact with recombinant gp160 (rgp160) produced in vaccinia virus-infected BHK21 cells. Specific binding of conglutinin to rgp160 was demonstrated by ELISA. The interaction of bovine conglutinin with rgp160...... of the binding of rgp160 to the CD4 receptor on CEM 13 cells, as demonstrated by FACS analyses. These results indicate that conglutinin may inhibit the infection with HIV-1 through its interaction with the viral envelope glycoprotein....

The function of yeast CAP family proteins in lipid export, mating, and pathogen defense.

Science.gov (United States)

Darwiche, Rabih; El Atab, Ola; Cottier, Stéphanie; Schneiter, Roger

2018-04-01

In their natural habitat, yeast cells are constantly challenged by changing environmental conditions and a fierce competition for limiting resources. To thrive under such conditions, cells need to adapt and divide quickly, and be able to neutralize the toxic compounds secreted by their neighbors. Proteins like the pathogen-related yeast, Pry proteins, which belong to the large CAP/SCP/TAPS superfamily, may have an important role in this function. CAP proteins are conserved from yeast to man and are characterized by a unique αβα sandwich fold. They are mostly secreted glycoproteins and have been implicated in many different physiological processes including pathogen defense, virulence, venom toxicity, and sperm maturation. Yeast members of this family bind and export sterols as well as fatty acids, and they render cells resistant to eugenol, an antimicrobial compound present in clove oil. CAP family members might thus exert their various physiological functions through binding, sequestration, and neutralization of such small hydrophobic compounds. © 2017 Federation of European Biochemical Societies.

The role of jasmonates in floral nectar secretion.

Directory of Open Access Journals (Sweden)

Venkatesan Radhika

Full Text Available Plants produce nectar in their flowers as a reward for their pollinators and most of our crops depend on insect pollination, but little is known on the physiological control of nectar secretion. Jasmonates are well-known for their effects on senescence, the development and opening of flowers and on plant defences such as extrafloral nectar. Their role in floral nectar secretion has, however, not been explored so far. We investigated whether jasmonates have an influence on floral nectar secretion in oil-seed rape, Brassica napus. The floral tissues of this plant produced jasmonic acid (JA endogenously, and JA concentrations peaked shortly before nectar secretion was highest. Exogenous application of JA to flowers induced nectar secretion, which was suppressed by treatment with phenidone, an inhibitor of JA synthesis. This effect could be reversed by additional application of JA. Jasmonoyl-isoleucine and its structural mimic coronalon also increased nectar secretion. Herbivory or addition of JA to the leaves did not have an effect on floral nectar secretion, demonstrating a functional separation of systemic defence signalling from reproductive nectar secretion. Jasmonates, which have been intensively studied in the context of herbivore defences and flower development, have a profound effect on floral nectar secretion and, thus, pollination efficiency in B. napus. Our results link floral nectar secretion to jasmonate signalling and thereby integrate the floral nectar secretion into the complex network of oxylipid-mediated developmental processes of plants.

Characterization of Vesicular Stomatitis Virus Recombinants That Express and Incorporate High Levels of Hepatitis C Virus Glycoproteins

OpenAIRE

Buonocore, Linda; Blight, Keril J.; Rice, Charles M.; Rose, John K.

2002-01-01

We generated recombinant vesicular stomatitis viruses (VSV) expressing genes encoding hybrid proteins consisting of the extracellular domains of hepatitis C virus (HCV) glycoproteins fused at different positions to the transmembrane and cytoplasmic domains of the VSV G glycoprotein (E1G and E2G). We show that these chimeric proteins are transported to the cell surface and incorporated into VSV virions efficiently. We also generated VSV recombinants in which the gene encoding the VSV G protein...

Non-redundant roles of phosphoinositide 3-kinase isoforms alpha and beta in glycoprotein VI-induced platelet signaling and thrombus formation.

Science.gov (United States)

Gilio, Karen; Munnix, Imke C A; Mangin, Pierre; Cosemans, Judith M E M; Feijge, Marion A H; van der Meijden, Paola E J; Olieslagers, Servé; Chrzanowska-Wodnicka, Magdalena B; Lillian, Rivka; Schoenwaelder, Simone; Koyasu, Shigeo; Sage, Stewart O; Jackson, Shaun P; Heemskerk, Johan W M

2009-12-04

Platelets are activated by adhesion to vascular collagen via the immunoglobulin receptor, glycoprotein VI (GPVI). This causes potent signaling toward activation of phospholipase Cgamma2, which bears similarity to the signaling pathway evoked by T- and B-cell receptors. Phosphoinositide 3-kinase (PI3K) plays an important role in collagen-induced platelet activation, because this activity modulates the autocrine effects of secreted ADP. Here, we identified the PI3K isoforms directly downstream of GPVI in human and mouse platelets and determined their role in GPVI-dependent thrombus formation. The targeting of platelet PI3Kalpha or -beta strongly and selectively suppressed GPVI-induced Ca(2+) mobilization and inositol 1,4,5-triphosphate production, thus demonstrating enhancement of phospholipase Cgamma2 by PI3Kalpha/beta. That PI3Kalpha and -beta have a non-redundant function in GPVI-induced platelet activation and thrombus formation was concluded from measurements of: (i) serine phosphorylation of Akt, (ii) dense granule secretion, (iii) intracellular Ca(2+) increases and surface expression of phosphatidylserine under flow, and (iv) thrombus formation, under conditions where PI3Kalpha/beta was blocked or p85alpha was deficient. In contrast, GPVI-induced platelet activation was insensitive to inhibition or deficiency of PI3Kdelta or -gamma. Furthermore, PI3Kalpha/beta, but not PI3Kgamma, contributed to GPVI-induced Rap1b activation and, surprisingly, also to Rap1b-independent platelet activation via GPVI. Together, these findings demonstrate that both PI3Kalpha and -beta isoforms are required for full GPVI-dependent platelet Ca(2+) signaling and thrombus formation, partly independently of Rap1b. This provides a new mechanistic explanation for the anti-thrombotic effect of PI3K inhibition and makes PI3Kalpha an interesting new target for anti-platelet therapy.

Secret-key expansion from covert communication

Science.gov (United States)

Arrazola, Juan Miguel; Amiri, Ryan

2018-02-01

Covert communication allows the transmission of messages in such a way that it is not possible for adversaries to detect that the communication is occurring. This provides protection in situations where knowledge that two parties are talking to each other may be incriminating to them. In this work, we study how covert communication can be used for a different purpose: secret key expansion. First, we show that any message transmitted in a secure covert protocol is also secret and therefore unknown to an adversary. We then propose a covert communication protocol where the amount of key consumed in the protocol is smaller than the transmitted key, thus leading to secure secret key expansion. We derive precise conditions for secret key expansion to occur, showing that it is possible when there are sufficiently low levels of noise for a given security level. We conclude by examining how secret key expansion from covert communication can be performed in a computational security model.

Identification of structural and secretory lectin-binding glycoproteins of normal and cancerous human prostate.

Science.gov (United States)

Lad, P M; Cooper, J F; Learn, D B; Olson, C V

1984-12-07

We have utilized the technique of lectin-loading of SDS gels with iodinated concanavalin A and wheat germ agglutinin to identify glycoproteins in prostatic and seminal fluids as well as in prostate tissue fractions. The following subunits which bound both lectins were detected: (a) 50, 43 and 38 kDa subunits common to prostatic and seminal fluids, and an additional 55 kDa subunit which predominates only in prostatic fluid; (b) 78, 55, 50 and 43 kDa subunits in prostatic tissue cytosol and (c) 195, 170, 135, 116 and 95 kDa subunits present in the particulate fractions of prostatic tissue. Immunoblotting using specific rabbit antibodies revealed the 50 kDa band to be prostatic acid phosphatase and the 38 kDa band to be prostate-specific antigen. Interestingly, antibodies directed toward prostatic acid phosphatase were found to cross-react with the 43 kDa band. Fractionation on sucrose gradients showed that several of these particulate glycoproteins were associated with a vesicle fraction enriched in adenylate cyclase activity, implying that they are plasma membrane glycoproteins. Comparison of soluble and particulate fractions of normal and cancerous tissue homogenates was made by densitometric scanning of autoradiograms of lectin-loaded gels. Similar relative intensities of lectin-binding were obtained for corresponding proteins in normal and cancerous tissue fractions. Also, immunoblotting showed no differences in prostatic acid phosphatase or prostate-specific antigen between normal and cancerous soluble homogenate fractions. Our results suggest that major lectin-binding proteins are conserved in the transition from normal to cancerous tissue. These results may be useful in developing a multiple-marker profile of metastatic prostate cancer and for the design of imaging agents, such as monoclonal antibodies, to prominent soluble and particulate prostate glycoproteins.

Protein and Glycoprotein Patterns Related to Morphogenesis in Mammillaria gracillis Pfeiff. Tissue Culture

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Biljana Balen

2002-01-01

Full Text Available As plants with Crassulacean Acid Metabolism (CAM, cacti are highly affected by artificial environmental conditions in tissue culture. Plants of Mammillaria gracillis Pfeiff. (Cactaceae propagated in vitro produced callus spontaneously. This habituated callus regenerated normal and hyperhydric shoots without the addition of growth regulators. In order to compare habituated callus with the tumorous one, cactus cells were transformed with two strains of Agrobacterium tumefaciens: the wild strain B6S3 (tumour line TW and the rooty mutant GV3101 (tumour line TR. Gene expression in cactus plants, habituated callus, regenerated shoots and two tumour lines was analysed at the level of cellular and extracellular protein and glycoprotein profiles. Proteins were separated by SDS-polyacrylamide gel electrophoresis and 2-D PAGE electrophoresis and silver stained. Concavalin A-peroxidase staining detected glycoproteins with D-manose in their glycan component on protein blots. Developmentally specific protein patterns of Mammillaria gracillis tissue lines were detected. The 2-D PAGE electrophoresis revealed some tissue specific protein groups. The cellular glycoprotein of 42 kDa detected by ConA was highly expressed in undifferentiated tissues (habituated callus, TW and TR tumours and in hyperhydric regenerants. Tumours produced extracellular proteins of 33, 23 and 22 kDa. The N glycosylation of cellular and extracellular proteins was related to specific developmental stage of cactus tissue.

Secretion of arsenic, cholesterol, vitamin E, and zinc from the site of arsenical melanosis and leucomelanosis in skin.

Science.gov (United States)

Yousuf, A K M; Misbahuddin, Mir; Rahman, Md Sayedur

2011-06-01

Melanosis and leucomelanosis with or without keratosis are the earliest symptoms of arsenicosis. Uneven distribution of arsenical melanosis and leucomelanosis in skin led us to investigate the possibility of preferential secretion of arsenic and three constituents of sweat; cholesterol, vitamin E, and zinc. Twenty-four-hour skin secretion was collected from skin lesions and unaffected sites of 20 patients. Skin secretions were collected from 20 people exposed to arsenic-contaminated drinking water and 20 healthy, unexposed individuals. The secretion of arsenic from the skin of healthy controls (mean ± SE; unit: μg/in.(2) of skin/24 h; chest: 0.6 ± 0.2; back: 0.3 ± 0.1; abdomen: 0.5 ± 0.2) was increased several folds in arsenic-exposed controls (chest: 8.4 ± 1.8; back: 8.3 ± 1.9; abdomen: 6.7 ± 1.8) and patients (chest: 9.2 ± 1.3; back: 7.8 ± 1.3; abdomen: 5.2 ± 1.0). There was no difference in the skin lesions and unaffected sites in patients. However, the secretion of cholesterol was significantly lower in the chest of patients (190 ± 36) and healthy controls (686 ± 100) (p vitamin E were low in healthy controls (chest: 8.5 ± 3.1; back: 5.2 ± 1.7; and abdomen: 8.7 ± 2.4), higher in arsenic-exposed controls (chest: 30.2 ± 8.1; back: 16.3 ± 8.9; and abdomen: 24.8 ± 9.3), and highest in patients [chest: 91.4 ± 14.9 (p skin lesions showed no alteration in secretion of arsenic, although the secretion of cholesterol, vitamin E, and zinc was changed. Potential implications are discussed.

Pancreatic bicarbonate secretion involves two proton pumps

DEFF Research Database (Denmark)

Novak, Ivana; Wang, Jing; Henriksen, Katrine L.

2011-01-01

Pancreas secretes fluid rich in digestive enzymes and bicarbonate. The alkaline secretion is important in buffering of acid chyme entering duodenum and for activation of enzymes. This secretion is formed in pancreatic ducts, and studies to date show that plasma membranes of duct epithelium expres...

Gastric secretion elicited by conditioning in rats.

Science.gov (United States)

Caboclo, José Liberato Ferreira; Cury, Francico de Assis; Borin, Aldenis Albanese; Caboclo, Luís Otávio Sales Ferreira; Ribeiro, Maria Fernanda Sales Caboclo; de Freitas, Pedro José; Andersson, Sven

2009-01-01

To investigate whether interdigestive gastric acid secretion can be controlled by a possible memory-related cortical mechanism. To evaluate gastric secretion in rats, we used a methodology that allows gastric juice collection in rats in their habitual conditions (without any restraining) by pairing sound as the conditioning stimulus (CS) and food as the unconditioning stimulus (US). The levels of gastric acid secretion under basal conditions and under sound stimulation were recorded and the circulating gastrin levels determined. When the gastric juice was collected in the course of the conditioning procedure, the results showed that under noise stimulation a significant increase in gastric acid secretion occurred after 10 days of conditioning (p<0.01). The significance was definitively demonstrated after 13 days of conditioning (p<0.001). Basal secretions of the conditioned rats reached a significant level after 16 days of conditioning. The levels of noise-stimulated gastric acid secretion were the highest so far described in physiological experiments carried out in rats and there were no significant increases in the circulating gastrin levels. The results point to the important role played by cortical structures in the control of interdigestive gastric acid secretion in rats. If this mechanism is also present in humans, it may be involved in diseases caused by inappropriate gastric acid secretion during the interprandial periods.

Gamma-radiolysis of some glycoproteins in dilute aqueous solutions

Energy Technology Data Exchange (ETDEWEB)

Nagrani, S

1981-01-01

A study has been made of the radiation-induced damage of some glycoproteins in dilute aqueous solutions. By use of specific radical scavengers, the roles of the individual free radicals, formed by ..gamma..-radiolysis, in causing damage has been assessed. The most effective radical in causing damage to human and porcine glycopolypeptide is the OH radical. The structure of the different blood group glycopolypeptides determines the sensitivity towards the free radical attack. The glycopolypeptide shows depolymerization and a characteristic absorption at approximately 270 nm due to the formation of additional products on irradiation. Chemical changes of the irradiated glycopolypeptide solutions revealed significant damage to the oligosaccharide chain and the polypeptide core of the glycopolypeptide. The radiation-induced inactivation of another glycoprotein, external yeast invertase, due to different radical species at pH 7.0 decreases in the following order: ea-barq > OH radical > (SCN) radical/sub 2//sup -/ > Br radical/sub 2//sup -/. The structure of this enzyme, accounts for the mechanism of enzyme inactivation and the relative damage of carbohydrate and amino acid residues. The irradiated enzyme solutions show significant changes in their electrophoretic behaviour on cellogel electrophoresis due to the formation of radiolysis products, which also show characteristic absorption maxima at approximately 275 nm. (author).

New insights into the Hendra virus attachment and entry process from structures of the virus G glycoprotein and its complex with Ephrin-B2.

Directory of Open Access Journals (Sweden)

Kai Xu

Full Text Available Hendra virus and Nipah virus, comprising the genus Henipavirus, are recently emerged, highly pathogenic and often lethal zoonotic agents against which there are no approved therapeutics. Two surface glycoproteins, the attachment (G and fusion (F, mediate host cell entry. The crystal structures of the Hendra G glycoprotein alone and in complex with the ephrin-B2 receptor reveal that henipavirus uses Tryptophan 122 on ephrin-B2/B3 as a "latch" to facilitate the G-receptor association. Structural-based mutagenesis of residues in the Hendra G glycoprotein at the receptor binding interface document their importance for viral attachments and entry, and suggest that the stability of the Hendra-G-ephrin attachment complex does not strongly correlate with the efficiency of viral entry. In addition, our data indicates that conformational rearrangements of the G glycoprotein head domain upon receptor binding may be the trigger leading to the activation of the viral F fusion glycoprotein during virus infection.

An alternative conformation of the gp41 heptad repeat 1 region coiled coil exists in the human immunodeficiency virus (HIV-1) envelope glycoprotein precursor

International Nuclear Information System (INIS)

Mische, Claudia C.; Yuan Wen; Strack, Bettina; Craig, Stewart; Farzan, Michael; Sodroski, Joseph

2005-01-01

The human immunodeficiency virus (HIV-1) transmembrane envelope glycoprotein, gp41, which mediates virus-cell fusion, exists in at least three different conformations within the trimeric envelope glycoprotein complex. The structures of the prefusogenic and intermediate states are unknown; structures representing the postfusion state have been solved. In the postfusion conformation, three helical heptad repeat 2 (HR2) regions pack in an antiparallel fashion into the hydrophobic grooves on the surface of a triple-helical coiled coil formed by the heptad repeat 1 (HR1) regions. We studied the prefusogenic conformation of gp41 by mutagenic alteration of membrane-anchored and soluble forms of the HIV-1 envelope glycoproteins. Our results indicate that, in the HIV-1 envelope glycoprotein precursor, the gp41 HR1 region is in a conformation distinct from that of a trimeric coiled coil. Thus, the central gp41 coiled coil is formed during the transition of the HIV-1 envelope glycoproteins from the precursor state to the receptor-bound intermediate

Human platelet glycoprotein Ia. One component is only expressed on the surface of activated platelets and may be a granule constituent

International Nuclear Information System (INIS)

Bienz, D.; Clemetson, K.J.

1989-01-01

Glycoprotein Ia (GP Ia) is a relatively minor component of human blood platelets thought to be a receptor involved in collagen-induced platelet activation. However, some difficulties exist with the definition of this glycoprotein. The expression of GP Ia on resting (prostacyclin analogue-treated) and thrombin-activated platelets was compared by surface labeling with 125 I-lactoperoxidase. Intact platelets or platelets solubilized in sodium dodecyl sulfate were labeled with periodate/[ 3 H]NaBH 4 . Analysis on two-dimensional isoelectric focusing/sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels showed that GP Ia is very poorly labeled in resting platelets. After activation a new spot (GP Ia*) appears with the same relative molecular mass as GP Ia under reducing conditions. GP Ia and Ia* can be clearly separated by two-dimensional nonreduced/reduced gel electrophoresis. Therefore, two glycoproteins which have been termed GP Ia exist in platelets with similar molecular weight and pI under reducing conditions. One of these (GP Ia*) is only surface-labeled when platelets are activated, indicating that it is only exposed on the surface of activated platelets. Supernatant from activated platelets contains this glycoprotein as well as other granule components. This glycoprotein is missing in platelets from two patients with collagen-response defects

High-performance liquid chromatography of human glycoprotein hormones.

Science.gov (United States)

Chlenov, M A; Kandyba, E I; Nagornaya, L V; Orlova, I L; Volgin, Y V

1993-02-12

The chromatographic behavior of the glycoprotein hormones from human pituitary glands and of placental origin [thyroid-stimulating hormone, luteinizing hormone and chorionic gonadotropin (CG)] was studied. It was shown that hydrophobic interaction chromatography on a microparticulate packing and anion-exchange HPLC can be applied for the purification of these hormones. Reversed-phase HPLC on wide-pore C4-bonded silica at neutral pH can be applied for the determination of the above hormones and for the isolation of pure CG and its subunits.

Magnetic enzyme reactors for isolation and study of heterogeneous glycoproteins

International Nuclear Information System (INIS)

Korecka, Lucie; Jezova, Jana; Bilkova, Zuzana; Benes, Milan; Horak, Daniel; Hradcova, Olga; Slovakova, Marcela; Viovy, Jean-Louis

2005-01-01

The newly developed magnetic micro- and nanoparticles with defined hydrophobicity and porosity were used for the preparation of magnetic enzyme reactors. Magnetic particles with immobilized proteolytic enzymes trypsin, chymotrypsin and papain and with enzyme neuraminidase were used to study the structure of heterogeneous glycoproteins. Factors such as the type of carrier, immobilization procedure, operational and storage stability, and experimental conditions were optimized

Air Force UAV’s: The Secret History

Science.gov (United States)

2010-07-01

iA Mitchell Institute Study i Air Force UAVs The Secret History A Mitchell Institute Study July 2010 By Thomas P. Ehrhard Report Documentation Page...DATES COVERED 00-00-2010 to 00-00-2010 4. TITLE AND SUBTITLE Air Force UAVs The Secret History 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c... The Secret History 2 Air Force UAVs: The Secret History2 air Force uaVs: The secret history Has any airplane in the past decade captured the public

Quantitative proteomic analysis for high-throughput screening of differential glycoproteins in hepatocellular carcinoma serum

International Nuclear Information System (INIS)

Gao, Hua-Jun; Chen, Ya-Jing; Zuo, Duo; Xiao, Ming-Ming; Li, Ying; Guo, Hua; Zhang, Ning; Chen, Rui-Bing

2015-01-01

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths. Novel serum biomarkers are required to increase the sensitivity and specificity of serum screening for early HCC diagnosis. This study employed a quantitative proteomic strategy to analyze the differential expression of serum glycoproteins between HCC and normal control serum samples. Lectin affinity chromatography (LAC) was used to enrich glycoproteins from the serum samples. Quantitative mass spectrometric analysis combined with stable isotope dimethyl labeling and 2D liquid chromatography (LC) separations were performed to examine the differential levels of the detected proteins between HCC and control serum samples. Western blot was used to analyze the differential expression levels of the three serum proteins. A total of 2,280 protein groups were identified in the serum samples from HCC patients by using the 2D LC-MS/MS method. Up to 36 proteins were up-regulated in the HCC serum, whereas 19 proteins were down-regulated. Three differential glycoproteins, namely, fibrinogen gamma chain (FGG), FOS-like antigen 2 (FOSL2), and α-1,6-mannosylglycoprotein 6-β-N-acetylglucosaminyltransferase B (MGAT5B) were validated by Western blot. All these three proteins were up-regulated in the HCC serum samples. A quantitative glycoproteomic method was established and proven useful to determine potential novel biomarkers for HCC

A Simplified Model of Glycoprotein Production within Cell Culture

OpenAIRE

Lambert, A. B.; Smith, F. T.; Velayudhan, A.

2017-01-01

Complex biological products, such as those used to treat various forms of cancer, are typically produced by mammalian cells in bioreactors. The most important class of such biological medicines is proteins. These typically bind to sugars (glycans) in a process known as glycosylation, creating glycoproteins, which are more stable and effective medicines. The glycans are large polymers that are formed by a long sequence of enzyme catalysed reactions. This sequence is not always completed, thus ...

Towards Comprehension of the ABCB1/P-Glycoprotein Role in Chronic Myeloid Leukemia

Directory of Open Access Journals (Sweden)

Raquel C. Maia

2018-01-01

Full Text Available Abstract: The introduction of imatinib (IM, a BCR-ABL1 tyrosine kinase inhibitor (TKI, has represented a significant advance in the first-line treatment of chronic myeloid leukemia (CML. However, approximately 30% of patients need to discontinue IM due to resistance or intolerance to this drug. Both resistance and intolerance have also been observed in treatment with the second-generation TKIs—dasatinib, nilotinib, and bosutinib—and the third-generation TKI—ponatinib. The mechanisms of resistance to TKIs may be BCR-ABL1-dependent and/or BCR-ABL1-independent. Although the role of efflux pump P-glycoprotein (Pgp, codified by the ABCB1 gene, is unquestionable in drug resistance of many neoplasms, a longstanding question exists about whether Pgp has a firm implication in TKI resistance in the clinical scenario. The goal of this review is to offer an overview of ABCB1/Pgp expression/activity/polymorphisms in CML. Understanding how interactions, associations, or cooperation between Pgp and other molecules—such as inhibitor apoptosis proteins, microRNAs, or microvesicles—impact IM resistance risk may be critical in evaluating the response to TKIs in CML patients. In addition, new non-TKI compounds may be necessary in order to overcome the resistance mediated by Pgp in CML.

Effect of acute bilateral adrenalectomy and reserpine on gastric ...

African Journals Online (AJOL)

STORAGESEVER

2008-09-03

Sep 3, 2008 ... the secretion of gastric mucus in a system where glycoprotein erosion is measured together with adherent mucus secretion in the gastric mucosa in the unstimu- lated state. Therefore, the present study was undertaken to examine the effect of acute bilateral adrenalectomy and dopamine depletory agent ...

Mutant tamm-horsfall glycoprotein accumulation in endoplasmic reticulum induces apoptosis reversed by colchicine and sodium 4-phenylbutyrate.

Science.gov (United States)

Choi, Sung Won; Ryu, Ok Hee; Choi, Sun Jin; Song, In Sun; Bleyer, Anthony J; Hart, Thomas C

2005-10-01

As a consequence of uromodulin gene mutations, individuals develop precocious hyperuricemia, gout, and progressive renal failure. In vitro studies suggest that pathologic accumulation of uromodulin/Tamm-Horsfall glycoprotein (THP) occurs in the endoplasmic reticulum (ER), but the pathophysiology of renal damage is unclear. It was hypothesized that programmed cell death triggered by accumulation of misfolded THP in the ER causes progressive renal disease. Stably transfected human embryonic kidney 293 cells and immortalized thick ascending limb of Henle's loop cells with wild-type and mutated uromodulin cDNA were evaluated to test this hypothesis. Immunocytochemistry, ELISA, and deglycosylation studies indicated that accumulation of mutant THP occurred in the ER. FACS analyses showed a significant increase in early apoptosis signal in human embryonic kidney 293 and thick ascending limb of Henle's loop cells that were transfected with mutant uromodulin constructs. Colchicine and sodium 4-phenylbutyrate treatment increased secretion of THP from the ER to the cell membrane and into the culture media and significantly improved cell viability. These findings indicate that intracellular accumulation of THP facilitates apoptosis and that this may provide the pathologic mechanism responsible for the progressive renal damage associated with uromodulin gene mutations. Colchicine and sodium 4-phenylbutyrate reverse these processes and could potentially be beneficial in ameliorating the progressive renal damage in uromodulin-associated kidney diseases.

Ca 125 and Ca 19-9: two cancer-associated sialylsaccharide antigens on a mucus glycoprotein from human milk.

Science.gov (United States)

Hanisch, F G; Uhlenbruck, G; Dienst, C; Stottrop, M; Hippauf, E

1985-06-03

The cancer-associated antigens Ca 125 and Ca 19-9 were demonstrated by radioimmunoassay to form structural units of a mucus glycoprotein in human milk taken from healthy women four days after parturition. The glycoprotein precipitated with the casein fraction at pH 4.6 and was completely absent in the whey as judged from Ca 19-9 assay. It could be effectively enriched by phenol-saline extraction from soluble milk proteins and further purified by gel filtration on Sephacryl S300 and Sephacryl S400. The active component with a bouyant density of 1.41 g/ml in isopycnic density gradient centrifugation (CsCl) shared common physico-chemical and chemical characteristics of mucus glycoproteins. Carbohydrates representing about 68% by weight were conjugated to protein by alkali-labile linkages, exclusively and were essentially free of D-mannose. Activities of Ca 125 and Ca 19-9 were both destroyed by treatment with periodate, mild alkali or neuraminidase suggesting the antigens are sialylated saccharides bound to protein by alkali-labile linkages. The fraction of monosialylated saccharide alditols isolated after reductive beta-elimination from the mucus glycoprotein was shown to inhibit monoclonal antibodies anti-(Ca 125) and anti-(Ca 19-9) in radioimmunoassay.

Genetic analysis of the SARS-coronavirus spike glycoprotein functional domains involved in cell-surface expression and cell-to-cell fusion

International Nuclear Information System (INIS)

Petit, Chad M.; Melancon, Jeffrey M.; Chouljenko, Vladimir N.; Colgrove, Robin; Farzan, Michael; Knipe, David M.; Kousoulas, K.G.

2005-01-01

The SARS-coronavirus (SARS-CoV) is the etiological agent of severe acute respiratory syndrome (SARS). The SARS-CoV spike (S) glycoprotein mediates membrane fusion events during virus entry and virus-induced cell-to-cell fusion. To delineate functional domains of the SARS-CoV S glycoprotein, single point mutations, cluster-to-lysine and cluster-to-alanine mutations, as well as carboxyl-terminal truncations were investigated in transient expression experiments. Mutagenesis of either the coiled-coil domain of the S glycoprotein amino terminal heptad repeat, the predicted fusion peptide, or an adjacent but distinct region, severely compromised S-mediated cell-to-cell fusion, while intracellular transport and cell-surface expression were not adversely affected. Surprisingly, a carboxyl-terminal truncation of 17 amino acids substantially increased S glycoprotein-mediated cell-to-cell fusion suggesting that the terminal 17 amino acids regulated the S fusogenic properties. In contrast, truncation of 26 or 39 amino acids eliminating either one or both of the two endodomain cysteine-rich motifs, respectively, inhibited cell fusion in comparison to the wild-type S. The 17 and 26 amino-acid deletions did not adversely affect S cell-surface expression, while the 39 amino-acid truncation inhibited S cell-surface expression suggesting that the membrane proximal cysteine-rich motif plays an essential role in S cell-surface expression. Mutagenesis of the acidic amino-acid cluster in the carboxyl terminus of the S glycoprotein as well as modification of a predicted phosphorylation site within the acidic cluster revealed that this amino-acid motif may play a functional role in the retention of S at cell surfaces. This genetic analysis reveals that the SARS-CoV S glycoprotein contains extracellular domains that regulate cell fusion as well as distinct endodomains that function in intracellular transport, cell-surface expression, and cell fusion

Mining the O-mannose glycoproteome reveals cadherins as major O-mannosylated glycoproteins

DEFF Research Database (Denmark)

Vester-Christensen, Malene B; Halim, Adnan; Joshi, Hiren Jitendra

2013-01-01

The metazoan O-mannose (O-Man) glycoproteome is largely unknown. It has been shown that up to 30% of brain O-glycans are of the O-Man type, but essentially only alpha-dystroglycan (α-DG) of the dystrophin-glycoprotein complex is well characterized as an O-Man glycoprotein. Defects in O-Man...... glycosylation underlie congenital muscular dystrophies and considerable efforts have been devoted to explore this O-glycoproteome without much success. Here, we used our SimpleCell strategy using nuclease-mediated gene editing of a human cell line (MDA-MB-231) to reduce the structural heterogeneity of O-Man...... glycans and to probe the O-Man glycoproteome. In this breast cancer cell line we found that O-Man glycosylation is primarily found on cadherins and plexins on β-strands in extracellular cadherin and Ig-like, plexin and transcription factor domains. The positions and evolutionary conservation of O-Man...

Secreted Phospholipases A₂ from Animal Venoms in Pain and Analgesia.

Science.gov (United States)

Zambelli, Vanessa O; Picolo, Gisele; Fernandes, Carlos A H; Fontes, Marcos R M; Cury, Yara

2017-12-19

Animal venoms comprise a complex mixture of components that affect several biological systems. Based on the high selectivity for their molecular targets, these components are also a rich source of potential therapeutic agents. Among the main components of animal venoms are the secreted phospholipases A₂ (sPLA₂s). These PLA₂ belong to distinct PLA₂s groups. For example, snake venom sPLA₂s from Elapidae and Viperidae families, the most important families when considering envenomation, belong, respectively, to the IA and IIA/IIB groups, whereas bee venom PLA₂ belongs to group III of sPLA₂s. It is well known that PLA₂, due to its hydrolytic activity on phospholipids, takes part in many pathophysiological processes, including inflammation and pain. Therefore, secreted PLA₂s obtained from animal venoms have been widely used as tools to (a) modulate inflammation and pain, uncovering molecular targets that are implicated in the control of inflammatory (including painful) and neurodegenerative diseases; (b) shed light on the pathophysiology of inflammation and pain observed in human envenomation by poisonous animals; and, (c) characterize molecular mechanisms involved in inflammatory diseases. The present review summarizes the knowledge on the nociceptive and antinociceptive actions of sPLA₂s from animal venoms, particularly snake venoms.

A quantum secret-sharing protocol with fairness

International Nuclear Information System (INIS)

Liu, Feng; Qin, Su-Juan; Wen, Qiao-Yan

2014-01-01

A quantum secret-sharing (QSS) protocol consists of two main phases, called sharing and reconstruction. In the first phase, the dealer selects a secret, divides it into several shares, and sends each participant its share securely with a quantum channel. In the second phase, the participants run an interactive protocol in order to reconstruct the secret. If the participants can communicate via a broadcast channel, they can show their shares and learn the secrets simultaneously. So what happens if the channel is not simultaneous? In this paper, we propose a QSS protocol with cheaters by using partially and maximally entangled states. A secure and fair reconstruction mechanism is designed, in a way that each participant can learn or cannot learn the secret simultaneously. (papers)

Characterization of host immune responses in Ebola virus infections.

Science.gov (United States)

Wong, Gary; Kobinger, Gary P; Qiu, Xiangguo

2014-06-01

Ebola causes highly lethal hemorrhagic fever in humans with no licensed countermeasures. Its virulence can be attributed to several immunoevasion mechanisms: an early inhibition of innate immunity started by the downregulation of type I interferon, epitope masking and subversion of the adaptive humoural immunity by secreting a truncated form of the viral glycoprotein. Deficiencies in specific and non-specific antiviral responses result in unrestricted viral replication and dissemination in the host, causing death typically within 10 days after the appearance of symptoms. This review summarizes the host immune response to Ebola infection, and highlights the short- and long-term immune responses crucial for protection, which holds implications for the design of future vaccines and therapeutics.

Human CRISP-3 binds serum alpha(1)B-glycoprotein across species

DEFF Research Database (Denmark)

Udby, Lene; Johnsen, Anders H; Borregaard, Niels

2010-01-01

CRISP-3 was previously shown to be bound to alpha(1)B-glycoprotein (A1BG) in human serum/plasma. All mammalian sera are supposed to contain A1BG, although its presence in rodent sera is not well-documented. Since animal sera are often used to supplement buffers in experiments, in particular...

Impact of alg3 gene deletion on growth, development, pigment production, protein secretion, and functions of recombinant Trichoderma reesei cellobiohydrolases in Aspergillus niger.

Science.gov (United States)

Dai, Ziyu; Aryal, Uma K; Shukla, Anil; Qian, Wei-Jun; Smith, Richard D; Magnuson, Jon K; Adney, William S; Beckham, Gregg T; Brunecky, Roman; Himmel, Michael E; Decker, Stephen R; Ju, Xiaohui; Zhang, Xiao; Baker, Scott E

2013-12-01

Dolichyl-P-Man:Man(5)GlcNAc(2)-PP-dolichyl α-1,3-mannosyltransferase (also known as "asparagine-linked glycosylation 3", or ALG3) is involved in early N-linked glycan synthesis and thus is essential for formation of N-linked protein glycosylation. In this study, we examined the effects of alg3 gene deletion (alg3Δ) on growth, development, pigment production, protein secretion and recombinant Trichoderma reesei cellobiohydrolase (rCel7A) expressed in Aspergillus niger. The alg3Δ delayed spore germination in liquid cultures of complete medium (CM), potato dextrose (PD), minimal medium (MM) and CM with addition of cAMP (CM+cAMP), and resulted in significant reduction of hyphal growth on CM, potato dextrose agar (PDA), and CM+cAMP and spore production on CM. The alg3Δ also led to a significant accumulation of red pigment on both liquid and solid CM cultures. The relative abundances of 54 of the total 215 proteins identified in the secretome were significantly altered as a result of alg3Δ, 63% of which were secreted at higher levels in alg3Δ strain than the parent. The rCel7A expressed in the alg3Δ mutant was smaller in size than that expressed in both wild-type and parental strains, but still larger than T. reesei Cel7A. The circular dichroism (CD)-melt scans indicated that change in glycosylation of rCel7A does not appear to impact the secondary structure or folding. Enzyme assays of Cel7A and rCel7A on nanocrystalline cellulose and bleached kraft pulp demonstrated that the rCel7As have improved activities on hydrolyzing the nanocrystalline cellulose. Overall, the results suggest that alg3 is critical for growth, sporulation, pigment production, and protein secretion in A. niger, and demonstrate the feasibility of this alternative approach to evaluate the roles of N-linked glycosylation in glycoprotein secretion and function. Copyright © 2013 Elsevier Inc. All rights reserved.

Up-regulation of P-glycoprotein expression by catalase via JNK activation in HepG2 cells.

Science.gov (United States)

Li, Lin; Xu, Jianfeng; Min, Taishan; Huang, Weida

2006-01-01

Overexpression of the MDR1 gene is one of the reasons for multidrug resistance (MDR). Some studies suggested that antioxidants could down-regulate MDR1 expression as a possible cancer treatment. In this report, we try to determine the effects of antioxidants (catalase or N-acetylcysteine [NAC]) on the regulation of intrinsic MDR1 overexpression in HepG2 cells. Adding catalase or N-acetylcysteine to the HepG2 culture led to a significant increase of MDR1 mRNA and P-glycoprotein drug transporter activity. After catalase or NAC treatment, a reduced intracellular reactive oxygen species (ROS) was observed. The JNK inhibitor SP600125 abolished the positive effects of catalase on drug transporter activity in a dose-dependent manner. Furthermore, the up-regulation of P-glycoprotein functions by catalase was only observed in HepG2 cells but not in other cell lines tested (MCF-7, A549, A431). These data suggested that catalase can up-regulate P-glycoprotein expression in HepG2 cells via reducing intracellular ROS, and JNK may mediate this process.

Palmitoylation of the cysteine-rich endodomain of the SARS-coronavirus spike glycoprotein is important for spike-mediated cell fusion

International Nuclear Information System (INIS)

Petit, Chad M.; Chouljenko, Vladimir N.; Iyer, Arun; Colgrove, Robin; Farzan, Michael; Knipe, David M.; Kousoulas, K.G.

2007-01-01

The SARS-coronavirus (SARS-CoV) is the etiological agent of the severe acute respiratory syndrome (SARS). The SARS-CoV spike (S) glycoprotein mediates membrane fusion events during virus entry and virus-induced cell-to-cell fusion. The cytoplasmic portion of the S glycoprotein contains four cysteine-rich amino acid clusters. Individual cysteine clusters were altered via cysteine-to-alanine amino acid replacement and the modified S glycoproteins were tested for their transport to cell-surfaces and ability to cause cell fusion in transient transfection assays. Mutagenesis of the cysteine cluster I, located immediately proximal to the predicted transmembrane, domain did not appreciably reduce cell-surface expression, although S-mediated cell fusion was reduced by more than 50% in comparison to the wild-type S. Similarly, mutagenesis of the cysteine cluster II located adjacent to cluster I reduced S-mediated cell fusion by more than 60% compared to the wild-type S, while cell-surface expression was reduced by less than 20%. Mutagenesis of cysteine clusters III and IV did not appreciably affect S cell-surface expression or S-mediated cell fusion. The wild-type S was palmitoylated as evidenced by the efficient incorporation of 3 H-palmitic acid in wild-type S molecules. S glycoprotein palmitoylation was significantly reduced for mutant glycoproteins having cluster I and II cysteine changes, but was largely unaffected for cysteine cluster III and IV mutants. These results show that the S cytoplasmic domain is palmitoylated and that palmitoylation of the membrane proximal cysteine clusters I and II may be important for S-mediated cell fusion

Trade secrets protection mode of nuclear power plant

International Nuclear Information System (INIS)

Zeng Bin

2015-01-01

The paper analyzes the legal environment in which nuclear power enterprises are stayed, and mainly discusses the business secret protection modes of China's nuclear power enterprises. It is expected to provide a revelation and help for these enterprises to protect their business secrets. Firstly, the paper briefly expounds the legal basis of business secret protection and China's legalization status in this regard. Then it mainly puts forward the business secret management framework and postulations for nuclear power enterprises, and key points in application and protection of nuclear power business secret. (author)

Development of oligoclonal nanobodies for targeting the tumor-associated glycoprotein 72 antigen

DEFF Research Database (Denmark)

Sharifzadeh, Zahra; Rahbarizadeh, Fatemeh; Shokrgozar, Mohammad Ali

2013-01-01

The tumor-associated glycoprotein 72 (TAG-72) is a membrane mucin whose over-expression is correlated with advanced tumor stage and increased invasion and metastasis. In this study, we identified a panel of four nanobodies, single variable domains of dromedary heavy-chain antibodies that specific...

The Opportunistic Pathogen Serratia marcescens Utilizes Type VI Secretion To Target Bacterial Competitors ▿†

Science.gov (United States)

Murdoch, Sarah L.; Trunk, Katharina; English, Grant; Fritsch, Maximilian J.; Pourkarimi, Ehsan; Coulthurst, Sarah J.

2011-01-01

The type VI secretion system (T6SS) is the most recently described and least understood of the protein secretion systems of Gram-negative bacteria. It is widely distributed and has been implicated in the virulence of various pathogens, but its mechanism and exact mode of action remain to be defined. Additionally there have been several very recent reports that some T6SSs can target bacteria rather than eukaryotic cells. Serratia marcescens is an opportunistic enteric pathogen, a class of bacteria responsible for a significant proportion of hospital-acquired infections. We describe the identification of a functional T6SS in S. marcescens strain Db10, the first report of type VI secretion by an opportunist enteric bacterium. The T6SS of S. marcescens Db10 is active, with secretion of Hcp to the culture medium readily detected, and is expressed constitutively under normal growth conditions from a large transcriptional unit. Expression of the T6SS genes did not appear to be dependent on the integrity of the T6SS. The S. marcescens Db10 T6SS is not required for virulence in three nonmammalian virulence models. It does, however, exhibit dramatic antibacterial killing activity against several other bacterial species and is required for S. marcescens to persist in a mixed culture with another opportunist pathogen, Enterobacter cloacae. Importantly, this antibacterial killing activity is highly strain specific, with the S. marcescens Db10 T6SS being highly effective against another strain of S. marcescens with a very similar and active T6SS. We conclude that type VI secretion plays a crucial role in the competitiveness, and thus indirectly the virulence, of S. marcescens and other opportunistic bacterial pathogens. PMID:21890705

Ionizing radiation in secret services' conspirative actions

International Nuclear Information System (INIS)

Vogel, H.; Lotz, P.; Vogel, B.

2007-01-01

Introduction: The death of Litvinenko has been reported by the media. It has raised the question whether this case had been unique. The fall of the wall has allowed a glimpse in the planning and comporting of a secret service. Material and method: Documents of the secret service of the former German democratic republic (GDR), books of defectors, and media reports about secret service actions with radiating substances have been analyzed. Results: Since decades, secret services have been using radioactive nuclides and radiation for their tasks. Several killings with radiation have been reported. A complicated logistic had been developed. Conclusion: Only singular cases of the employment of radiating substances have become known. It is probable that the majority rests unknown. Government support seems necessary in secret services' conspirative actions with radiating substance

Lack of Abcg1 results in decreased plasma HDL cholesterol levels and increased biliary cholesterol secretion in mice fed a high cholesterol diet

NARCIS (Netherlands)

Wiersma, Harmen; Nijstad, Niels; de Boer, Jan Freark; Out, Ruud; Hogewerf, Wytse; Van Berkel, Theo J.; Kuipers, Folkert; Tietge, Uwe J. F.

Objective: The ATP Binding Cassette transporter G1 (ABCG1) has been implicated in cholesterol efflux towards HDL and reverse cholesterol transport (RCT). Biliary cholesterol secretion is considered as an important step in RCT. The aim of the present study was to determine the consequences of Abcg1

AoS28D, a proline-Xaa carboxypeptidase secreted by Aspergillus oryzae.

Science.gov (United States)

Salamin, Karine; Eugster, Philippe J; Jousson, Olivier; Waridel, Patrice; Grouzmann, Eric; Monod, Michel

2017-05-01

Prolyl peptidases of the MEROPS S28 family are of particular interest because they are key enzymes in the digestion of proline-rich peptides. A BLAST analysis of the Aspergillus oryzae genome revealed sequences coding for four proteases of the S28 family. Three of these proteases, AoS28A, AoS28B, and AoS28C, were previously characterized as acidic prolyl endopeptidases. The fourth protease, AoS28D, showed high sequence divergence with other S28 proteases and belongs to a phylogenetically distinct cluster together with orthologous proteases from other Aspergillus species. The objective of the present paper was to characterize AoS28D protease in terms of substrate specificity and activity. AoS28D produced by gene overexpression in A. oryzae and in Pichia pastoris was a 70-kDa glycoprotein with a 10-kDa sugar moiety. In contrast with other S28 proteases, AoS28D did not hydrolyze internal Pro-Xaa bonds of several tested peptides. Similarly, to human lysosomal Pro-Xaa carboxypeptidase, AoS28D demonstrated selectivity for cleaving C-terminal Pro-Xaa bonds which are resistant to carboxypeptidases of the S10 family concomitantly secreted by A. oryzae. Therefore, AoS28D could act in synergy with these enzymes during sequential degradation of a peptide from its C-terminus.

Antigiardial activity of glycoproteins and glycopeptides from Ziziphus honey.

Science.gov (United States)

Mohammed, Seif Eldin A; Kabashi, Ahmed S; Koko, Waleed S; Azim, M Kamran

2015-01-01

Natural honey contains an array of glycoproteins, proteoglycans and glycopeptides. Size-exclusion chromatography fractionated Ziziphus honey proteins into five peaks with molecular masses in the range from 10 to >200 kDa. The fractionated proteins exhibited in vitro activities against Giardia lamblia with IC50 values ≤ 25 μg/mL. Results indicated that honey proteins were more active as antiprotozoal agents than metronidazole. This study indicated the potential of honey proteins and peptides as novel antigiardial agents.

Regulation of glucagon secretion by incretins

DEFF Research Database (Denmark)

Holst, Jens Juul; Christensen, M; Lund, A

2011-01-01

Glucagon secretion plays an essential role in the regulation of hepatic glucose production, and elevated fasting and postprandial plasma glucagon concentrations in patients with type 2 diabetes (T2DM) contribute to their hyperglycaemia. The reason for the hyperglucagonaemia is unclear, but recent...... studies have shown lack of suppression after oral but preserved suppression after isoglycaemic intravenous glucose, pointing to factors from the gut. Gastrointestinal hormones that are secreted in response to oral glucose include glucagon-like peptide-1 (GLP-1) that strongly inhibits glucagon secretion......, and GLP-2 and GIP, both of which stimulate secretion. When the three hormones are given together on top of isoglycaemic intravenous glucose, glucagon suppression is delayed in a manner similar to that observed after oral glucose. Studies with the GLP-1 receptor antagonist, exendin 9-39, suggest...

Role of adipose secreted factors and kisspeptin in the metabolic control of gonadotropin secretion and puberty

Science.gov (United States)

Factors secreted by adipose tissue continue to be discovered. Evidence indicates a strong link between neural influences and adipocyte expression and secretion of a wide array of cytokines, neurotrophic factors, growth factors, binding proteins, and neuropeptides. These “adipokines” are linked to im...

Isolation and characterization of broadly neutralizing human monoclonal antibodies to the e1 glycoprotein of hepatitis C virus

DEFF Research Database (Denmark)

Meunier, Jean-Christophe; Russell, Rodney S.; Goossens, Vera

2008-01-01

The relative importance of humoral and cellular immunity in the prevention or clearance of hepatitis C virus (HCV) infection is poorly understood. However, there is considerable evidence that neutralizing antibodies are involved in disease control. Here we describe the detailed analysis of human...... monoclonal antibodies (MAbs) directed against HCV glycoprotein E1, which may have the potential to control HCV infection. We have identified two MAbs that can strongly neutralize HCV-pseudotyped particles (HCVpp) bearing the envelope glycoproteins of genotypes 1a, 1b, 4a, 5a, and 6a and less strongly...... neutralize HCVpp bearing the envelope glycoproteins of genotype 2a. Genotype 3a was not neutralized. The epitopes for both MAbs were mapped to the region encompassing amino acids 313 to 327. In addition, robust neutralization was also observed against cell culture-adapted viruses of genotypes 1a and 2a...

Burkholderia cenocepacia type VI secretion system mediates escape of type II secreted proteins into the cytoplasm of infected macrophages.

Directory of Open Access Journals (Sweden)

Roberto Rosales-Reyes

Full Text Available Burkholderia cenocepacia is an opportunistic pathogen that survives intracellularly in macrophages and causes serious respiratory infections in patients with cystic fibrosis. We have previously shown that bacterial survival occurs in bacteria-containing membrane vacuoles (BcCVs resembling arrested autophagosomes. Intracellular bacteria stimulate IL-1β secretion in a caspase-1-dependent manner and induce dramatic changes to the actin cytoskeleton and the assembly of the NADPH oxidase complex onto the BcCV membrane. A Type 6 secretion system (T6SS is required for these phenotypes but surprisingly it is not required for the maturation arrest of the BcCV. Here, we show that macrophages infected with B. cenocepacia employ the NLRP3 inflammasome to induce IL-1β secretion and pyroptosis. Moreover, IL-1β secretion by B. cenocepacia-infected macrophages is suppressed in deletion mutants unable to produce functional Type VI, Type IV, and Type 2 secretion systems (SS. We provide evidence that the T6SS mediates the disruption of the BcCV membrane, which allows the escape of proteins secreted by the T2SS into the macrophage cytoplasm. This was demonstrated by the activity of fusion derivatives of the T2SS-secreted metalloproteases ZmpA and ZmpB with adenylcyclase. Supporting this notion, ZmpA and ZmpB are required for efficient IL-1β secretion in a T6SS dependent manner. ZmpA and ZmpB are also required for the maturation arrest of the BcCVs and bacterial intra-macrophage survival in a T6SS-independent fashion. Our results uncover a novel mechanism for inflammasome activation that involves cooperation between two bacterial secretory pathways, and an unanticipated role for T2SS-secreted proteins in intracellular bacterial survival.

Glycan Reader: Automated Sugar Identification and Simulation Preparation for Carbohydrates and Glycoproteins

Science.gov (United States)

Jo, Sunhwan; Song, Kevin C.; Desaire, Heather; MacKerell, Alexander D.; Im, Wonpil

2011-01-01

Understanding how glycosylation affects protein structure, dynamics, and function is an emerging and challenging problem in biology. As a first step toward glycan modeling in the context of structural glycobiology, we have developed Glycan Reader and integrated it into the CHARMM-GUI, http://www.charmm-gui.org/input/glycan. Glycan Reader greatly simplifies the reading of PDB structure files containing glycans through (i) detection of carbohydrate molecules, (ii) automatic annotation of carbohydrates based on their three-dimensional structures, (iii) recognition of glycosidic linkages between carbohydrates as well as N-/O-glycosidic linkages to proteins, and (iv) generation of inputs for the biomolecular simulation program CHARMM with the proper glycosidic linkage setup. In addition, Glycan Reader is linked to other functional modules in CHARMM-GUI, allowing users to easily generate carbohydrate or glycoprotein molecular simulation systems in solution or membrane environments and visualize the electrostatic potential on glycoprotein surfaces. These tools are useful for studying the impact of glycosylation on protein structure and dynamics. PMID:21815173

Visualization of glucagon secretion from pancreatic α cells by bioluminescence video microscopy: Identification of secretion sites in the intercellular contact regions

International Nuclear Information System (INIS)

Yokawa, Satoru; Suzuki, Takahiro; Inouye, Satoshi; Inoh, Yoshikazu; Suzuki, Ryo; Kanamori, Takao; Furuno, Tadahide; Hirashima, Naohide

2017-01-01

We have firstly visualized glucagon secretion using a method of video-rate bioluminescence imaging. The fusion protein of proglucagon and Gaussia luciferase (PGCG-GLase) was used as a reporter to detect glucagon secretion and was efficiently expressed in mouse pancreatic α cells (αTC1.6) using a preferred human codon-optimized gene. In the culture medium of the cells expressing PGCG-GLase, luminescence activity determined with a luminometer was increased with low glucose stimulation and KCl-induced depolarization, as observed for glucagon secretion. From immunochemical analyses, PGCG-GLase stably expressed in clonal αTC1.6 cells was correctly processed and released by secretory granules. Luminescence signals of the secreted PGCG-GLase from the stable cells were visualized by video-rate bioluminescence microscopy. The video images showed an increase in glucagon secretion from clustered cells in response to stimulation by KCl. The secretory events were observed frequently at the intercellular contact regions. Thus, the localization and frequency of glucagon secretion might be regulated by cell-cell adhesion. - Highlights: • The fused protein of proglucagon to Gaussia luciferase was used as a reporter. • The fusion protein was highly expressed using a preferred human-codon optimized gene. • Glucagon secretion stimulated by depolarization was determined by luminescence. • Glucagon secretion in α cells was visualized by bioluminescence imaging. • Glucagon secretion sites were localized in the intercellular contact regions.

29 CFR 1903.9 - Trade secrets.

Science.gov (United States)

2010-07-01

... INSPECTIONS, CITATIONS AND PROPOSED PENALTIES § 1903.9 Trade secrets. (a) Section 15 of the Act provides: “All... concerns or relates to the trade secrets, processes, operations, style of work, or apparatus, or to the...

Ecdysteroid-stimulated synthesis and secretion of an N-acetyl-D-glucosamine-rich glycopeptide in a lepidopteran cell line derived from imaginal discs.

Science.gov (United States)

Porcheron, P; Morinière, M; Coudouel, N; Oberlander, H

1991-01-01

Hormone-regulated processing of N-acetyl-D-glucosamine was studied in an insect cell line derived from imaginal wing discs of the Indian meal moth, Plodia interpunctella (Hübner). The cell line, IAL-PID2, responded to treatment with 20-hydroxyecdysone with increased incorporation of GlcNAc into glycoproteins. Cycloheximide and tunicamycin counteracted the action of the hormone. In particular, treatment with 20-hydroxyecdysone resulted in the secretion of a 5,000 dalton N-acetyl-D-glucosamine-rich glycopeptide by the IAL-PID2 cells. Accumulation of this peptide was prevented by the use of teflubenzuron, a potent chitin synthesis inhibitor. A glycopeptide of similar molecular weight was observed in imaginal discs of P. interpunctella treated with 20-hydroxyecdysone in vitro, under conditions that induce chitin synthesis. Although the function of the 5,000 dalton glycopeptide is not known, we believe that the PID2 cell line is a promising model for molecular analysis of ecdysteroid-regulated processing of aminosugars by epidermal cells during insect development.

Air Force UAVs: The Secret History

Science.gov (United States)

2010-07-01

iA Mitchell Institute Study i Air Force UAVs The Secret History A Mitchell Institute Study July 2010 By Thomas P. Ehrhard Report Documentation Page...DATES COVERED 00-00-2010 to 00-00-2010 4. TITLE AND SUBTITLE Air Force UAVs The Secret History 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c...opening phases of Operation Enduring Freedom in Afghanistan. By Thomas P. Ehrhard a miTchEll insTiTuTE sTudy July 2010 Air Force UAVs The Secret History

Multi-drug resistance (MDR1 gene and P-glycoprotein influence on pharmacokinetic and pharmacodymanic of therapeutic drugs

Directory of Open Access Journals (Sweden)

Linardi Renata Lehn

2006-01-01

Full Text Available (MDR1 gene expressed in tumor cells and also in several normal tissues, such as intestine, liver, kidney, blood-brain barrier, spinal cord, and placenta. P-gp has been identified in mice, rat, bovine, monkey, rodents, and human beings and has been receiving a particular clinical relevance because this protein expression limits brain access and intestinal absorption of many drugs. This protein plays a role as a protective barrier against a wide variety of substrates, avoiding drug entry into the central nervous system. P-glycoprotein also interferes with drug bioavailability and disposition, including absorption, distribution, metabolization, and excretion, influencing pharmacokinetic and pharmacodynamic of drugs. Modulation of P-gp may help the efficacy of treatment of several diseases and can explain some adverse central nervous system effects induced by drugs after intravenous administration and the poor response of oral administration in patients. Alteration in P-gp expression or function has been associated with several diseases susceptibility in humans and animals. Furthermore, additional studies relating MDR1 and P-gp expression has an important clinical implication also in terms of treatment efficacy.

THE BUFFER CAPACITY OF AIRWAY EPITHELIAL SECRETIONS

Directory of Open Access Journals (Sweden)

Dusik eKim

2014-06-01

Full Text Available The pH of airway epithelial secretions influences bacterial killing and mucus properties and is reduced by acidic pollutants, gastric reflux, and respiratory diseases such as cystic fibrosis (CF. The effect of acute acid loads depends on buffer capacity, however the buffering of airway secretions has not been well characterized. In this work we develop a method for titrating micro-scale (30 µl volumes and use it to study fluid secreted by the human airway epithelial cell line Calu-3, a widely used model for submucosal gland serous cells. Microtitration curves revealed that HCO3- is the major buffer. Peak buffer capacity (β increased from 17 to 28 mM/pH during forskolin stimulation, and was reduced by >50% in fluid secreted by cystic fibrosis transmembrane conductance regulator (CFTR-deficient Calu-3 monolayers, confirming an important role of CFTR in HCO3- secretion. Back-titration with NaOH revealed non-volatile buffer capacity due to proteins synthesized and released by the epithelial cells. Lysozyme and mucin concentrations were too low to buffer Calu-3 fluid significantly, however model titrations of porcine gastric mucins at concentrations near the sol-gel transition suggest that mucins may contribute to the buffer capacity of ASL in vivo. We conclude that CFTR-dependent HCO3- secretion and epithelially-derived proteins are the predominant buffers in Calu-3 secretions.

Endocytic Pathways Involved in Filovirus Entry: Advances, Implications and Future Directions

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Suchita Bhattacharyya

2012-12-01

Full Text Available Detailed knowledge of the host-virus interactions that accompany filovirus entry into cells is expected to identify determinants of viral virulence and host range, and to yield targets for the development of antiviral therapeutics. While it is generally agreed that filovirus entry into the host cytoplasm requires viral internalization into acidic endosomal compartments and proteolytic cleavage of the envelope glycoprotein by endo/lysosomal cysteine proteases, our understanding of the specific endocytic pathways co-opted by filoviruses remains limited. This review addresses the current knowledge on cellular endocytic pathways implicated in filovirus entry, highlights the consensus as well as controversies, and discusses important remaining questions.

Characterization of monomeric intermediates during VSV glycoprotein structural transition.

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Aurélie A Albertini

2012-02-01

Full Text Available Entry of enveloped viruses requires fusion of viral and cellular membranes, driven by conformational changes of viral glycoproteins. Crystal structures provide static pictures of pre- and post-fusion conformations of these proteins but the transition pathway remains elusive. Here, using several biophysical techniques, including analytical ultracentrifugation, circular dichroïsm, electron microscopy and small angle X-ray scattering, we have characterized the low-pH-induced fusogenic structural transition of a soluble form of vesicular stomatitis virus (VSV glycoprotein G ectodomain (G(th, aa residues 1-422, the fragment that was previously crystallized. While the post-fusion trimer is the major species detected at low pH, the pre-fusion trimer is not detected in solution. Rather, at high pH, G(th is a flexible monomer that explores a large conformational space. The monomeric population exhibits a marked pH-dependence and adopts more elongated conformations when pH decreases. Furthermore, large relative movements of domains are detected in absence of significant secondary structure modification. Solution studies are complemented by electron micrographs of negatively stained viral particles in which monomeric ectodomains of G are observed at the viral surface at both pH 7.5 and pH 6.7. We propose that the monomers are intermediates during the conformational change and thus that VSV G trimers dissociate at the viral surface during the structural transition.

Mechanism of feline immunodeficiency virus envelope glycoprotein-mediated fusion

International Nuclear Information System (INIS)

Garg, Himanshu; Fuller, Frederick J.; Tompkins, Wayne A.F.

2004-01-01

Feline immunodeficiency virus (FIV) shares remarkable homology to primate lentiviruses, human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV). The process of lentiviral env glycoprotein-mediated fusion of membranes is essential for viral entry and syncytia formation. A detailed understanding of this phenomenon has helped identify new targets for antiviral drug development. Using a model based on syncytia formation between FIV env-expressing cells and a feline CD4+ T cell line we have studied the mechanism of FIV env-mediated fusion. Using this model we show that FIV env-mediated fusion mechanism and kinetics are similar to HIV env. Syncytia formation could be blocked by CXCR4 antagonist AMD3100, establishing the importance of this receptor in FIV gp120 binding. Interestingly, CXCR4 alone was not sufficient to allow fusion by a primary isolate of FIV, as env glycoprotein from FIV-NCSU 1 failed to induce syncytia in several feline cell lines expressing CXCR4. Syncytia formation could be inhibited at a post-CXCR4 binding step by synthetic peptide T1971, which inhibits interaction of heptad repeat regions of gp41 and formation of the hairpin structure. Finally, using site-directed mutagenesis, we also show that a conserved tryptophan-rich region in the membrane proximal ectodomain of gp41 is critical for fusion, possibly at steps post hairpin structure formation

Zonal variation in the distribution of an alpha 1-acid glycoprotein glycoform receptor in human adrenal cortex

DEFF Research Database (Denmark)

Andersen, U O; Bøg-Hansen, T C; Kirkeby, S

1999-01-01

receptor was located in the cytoplasm of glomerulosa and outer fasciculata cells. The intensity of the reaction product decreased in the fasciculata, and no staining was seen in inner fasciculata and reticularis. Inhibition with the simple sugars, mannose and GlcNAc confirmed a lectin-like reaction...... specific receptor. The binding of alpha 1-acid glycoprotein glycoform B and alpha 1-acid glycoprotein glycoform C to the glycoform specific receptor is inhibited by the steroid hormones cortisone, aldosterone, estradiol and progesterone but not by testosterone. The pronounced changes in the distribution...

DNA vaccine expressing herpes simplex virus 1 glycoprotein C and D protects mice against herpes simplex keratitis

OpenAIRE

Li-Li Dong; Ru Tang; Yu-Jia Zhai; Tejsu Malla; Kai Hu

2017-01-01

AIM: To investigate whether DNA vaccine encoding herpes simplex virus 1 (HSV-1) glycoprotein C (gC) and glycoprotein D (gD) will achieve better protective effect against herpes simplex keratitis (HSK) than DNA vaccine encoding gD alone. METHODS: DNA vaccine expressing gD or gC combined gD (gD.gC) were constructed and carried by chitosan nanoparticle. The expression of fusion protein gD and gC were detected in DNA/nanoparticle transfected 293T cells by Western-blot. For immunization, mice w...

Inhibition of Lassa virus glycoprotein cleavage and multicycle replication by site 1 protease-adapted alpha(1-antitrypsin variants.

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Anna Maisa

2009-06-01

Full Text Available Proteolytic processing of the Lassa virus envelope glycoprotein precursor GP-C by the host proprotein convertase site 1 protease (S1P is a prerequisite for the incorporation of the subunits GP-1 and GP-2 into viral particles and, hence, essential for infectivity and virus spread. Therefore, we tested in this study the concept of using S1P as a target to block efficient virus replication.We demonstrate that stable cell lines inducibly expressing S1P-adapted alpha(1-antitrypsin variants inhibit the proteolytic maturation of GP-C. Introduction of the S1P recognition motifs RRIL and RRLL into the reactive center loop of alpha(1-antitrypsin resulted in abrogation of GP-C processing by endogenous S1P to a similar level observed in S1P-deficient cells. Moreover, S1P-specific alpha(1-antitrypsins significantly inhibited replication and spread of a replication-competent recombinant vesicular stomatitis virus expressing the Lassa virus glycoprotein GP as well as authentic Lassa virus. Inhibition of viral replication correlated with the ability of the different alpha(1-antitrypsin variants to inhibit the processing of the Lassa virus glycoprotein precursor.Our data suggest that glycoprotein cleavage by S1P is a promising target for the development of novel anti-arenaviral strategies.

Extrafloral nectar secretion from wounds of Solanum dulcamara.

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Lortzing, Tobias; Calf, Onno W; Böhlke, Marlene; Schwachtje, Jens; Kopka, Joachim; Geuß, Daniel; Kosanke, Susanne; van Dam, Nicole M; Steppuhn, Anke

2016-04-25

Plants usually close wounds rapidly to prevent infections and the loss of valuable resources such as assimilates(1). However, herbivore-inflicted wounds on the bittersweet nightshade Solanum dulcamara appear not to close completely and produce sugary wound secretions visible as droplets. Many plants across the plant kingdom secrete sugary nectar from extrafloral nectaries(2) to attract natural enemies of herbivores for indirect defence(3,4). As ants forage on wound edges of S. dulcamara in the field, we hypothesized that wound secretions are a form of extrafloral nectar (EFN). We show that, unlike EFN from known nectaries, wound secretions are neither associated with any specific structure nor restricted to certain locations. However, similar to EFN, they are jasmonate-inducible and the plant controls their chemical composition. Wound secretions are attractive for ants, and application of wound secretion mimics increases ant attraction and reduces herbivory on S. dulcamara plants in a natural population. In greenhouse experiments, we reveal that ants can defend S. dulcamara from two of its native herbivores, slugs and flea beetle larvae. Since nectar is defined by its ecological function as a sugary secretion involved in interactions with animals(5), such 'plant bleeding' could be a primitive mode of nectar secretion exemplifying an evolutionary origin of structured extrafloral nectaries.

Incretin hormone secretion over the day

DEFF Research Database (Denmark)

Ahren, B; Carr, RD; Deacon, Carolyn F.

2010-01-01

The two incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are key factors in the regulation of islet function and glucose metabolism, and incretin-based therapy for type 2 diabetes has gained considerable interest during recent years. Regulat......The two incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are key factors in the regulation of islet function and glucose metabolism, and incretin-based therapy for type 2 diabetes has gained considerable interest during recent years....... Regulation of incretin hormone secretion is less well characterized. The main stimulus for incretin hormone secretion is presence of nutrients in the intestinal lumen, and carbohydrate, fat as well as protein all have the capacity to stimulate GIP and GLP-1 secretion. More recently, it has been established...... that a diurnal regulation exists with incretin hormone secretion to an identical meal being greater when the meal is served in the morning compared to in the afternoon. Finally, whether incretin hormone secretion is altered in disease states is an area with, so far, controversial results in different studies...

Exosome secretion affects social motility in Trypanosoma brucei.

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Dror Eliaz

2017-03-01

Full Text Available Extracellular vesicles (EV secreted by pathogens function in a variety of biological processes. Here, we demonstrate that in the protozoan parasite Trypanosoma brucei, exosome secretion is induced by stress that affects trans-splicing. Following perturbations in biogenesis of spliced leader RNA, which donates its spliced leader (SL exon to all mRNAs, or after heat-shock, the SL RNA is exported to the cytoplasm and forms distinct granules, which are then secreted by exosomes. The exosomes are formed in multivesicular bodies (MVB utilizing the endosomal sorting complexes required for transport (ESCRT, through a mechanism similar to microRNA secretion in mammalian cells. Silencing of the ESCRT factor, Vps36, compromised exosome secretion but not the secretion of vesicles derived from nanotubes. The exosomes enter recipient trypanosome cells. Time-lapse microscopy demonstrated that cells secreting exosomes or purified intact exosomes affect social motility (SoMo. This study demonstrates that exosomes are delivered to trypanosome cells and can change their migration. Exosomes are used to transmit stress signals for communication between parasites.

Clearance and binding of radiolabeled glycoproteins by cells of the murine mononuclear phagocyte system

International Nuclear Information System (INIS)

Imber, M.J.

1982-01-01

The clearance and binding of radiolabeled lactoferrin and fast α 2 -macroglobulin were studied. Both glycoproteins cleared rapidly following intravenous injection in mice, and both bound specifically to discrete receptors on murine peritoneal macrophages. The simultaneous presence of excess, unlabeled ligands specific for receptors recognizing terminal fucose, mannose, N-acetylglucosamine or galactose residues did not inhibit the clearance or binding of either lactoferrin or fast-α 2 M. The clearance and binding of enzymatically defucosylated lactoferrin was indistinguishable from native lactoferrin, indicating that terminal α(1-3)-linked fucose on lactoferrin is not necessary for receptor recognition. The clearance and binding of two fast -α 2 M forms, α 2 M-trypsin and α 2 M-MeNH 2 cross compete with each other. Saturation binding studies indicated that the total binding of mannosyl -BSA, fusocyl-BSA, and N-acetylglucosaminyl-BSA to macrophages activated by BCG was approximately 15% of the levels observed with inflammatory macrophages elicited by thioglycollate broth. Cross-competition binding studies demonstrated a common surface receptor mediated binding of all three neoglycoprotein ligands and was identical to the receptor on mononuclear phagocytes that binds mannosyl- and N-acetylglucosaminyl-terminated glycoproteins. These results suggest that difference between discrete states of macrophage function may be correlated with selective changes in levels of the surface receptor for mannose-containing glycoproteins

Characterization of canine herpesvirus glycoprotein C expressed by a recombinant baculovirus in insect cells.

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Xuan, X; Maeda, K; Mikami, T; Otsuka, H

1996-12-01

The gene encoding the canine herpesvirus (CHV) glycoprotein C (gC) homologue has been identified by sequence homology analyses with other well studied herpesviruses. Previously, we have identified three CHV glycoproteins, gp145/112, gp80 and gp47 using a panel of monoclonal antibodies (MAbs). To determine which CHV glycoprotein corresponds to gC, a recombinant baculovirus which contains the putative CHV gC structural gene under the baculovirus polyhedrin promoter was constructed. The recombinant baculovirus expressed gC-related polypeptides (44-62 kDa), which reacted only with MAbs against CHV gp80, indicating that the previously identified CHV gp80 is the translation product of the gC gene. The baculovirus expressed gC was glycosylated and transported to the surface of infected cells. At least seven neutralizing epitopes were conserved on the gC produced in insect cells. It was found that the recombinant baculovirus infected cells adsorbed murine erythrocytes as is the case for CHV-infected cells. The hemadsorption activity was inhibited by heparin, indicating that the CHV gC binds to heparan sulfate on the surface of murine erythrocytes. Mice immunized with the recombinant gC produced strong neutralizing antibodies. Our results suggest that CHV gC produced in insect cells may be useful as a subunit vaccine to control CHV infections.

Interaction and interdependent packaging of tegument protein UL11 and glycoprotein e of herpes simplex virus.

Science.gov (United States)

Han, Jun; Chadha, Pooja; Meckes, David G; Baird, Nicholas L; Wills, John W

2011-09-01

The UL11 tegument protein of herpes simplex virus plays a critical role in the secondary envelopment; however, the mechanistic details remain elusive. Here, we report a new function of UL11 in the budding process in which it directs efficient acquisition of glycoprotein E (gE) via a direct interaction. In vitro binding assays showed that the interaction required only the first 28, membrane-proximal residues of the cytoplasmic tail of gE, and the C-terminal 26 residues of UL11. A second, weaker binding site was also found in the N-terminal half of UL11. The significance of the gE-UL11 interaction was subsequently investigated with viral deletion mutants. In the absence of the gE tail, virion packaging of UL11, but not other tegument proteins such as VP22 and VP16, was reduced by at least 80%. Reciprocally, wild-type gE packaging was also drastically reduced by about 87% in the absence of UL11, and this defect could be rescued in trans by expressing U(L)11 at the U(L)35 locus. Surprisingly, a mutant that lacks the C-terminal gE-binding site of UL11 packaged nearly normal amounts of gE despite its strong interaction with the gE tail in vitro, indicating that the interaction with the UL11 N terminus may be important. Mutagenesis studies of the UL11 N terminus revealed that the association of UL11 with membrane was not required for this function. In contrast, the UL11 acidic cluster motif was found to be critical for gE packaging and was not replaceable with foreign acidic clusters. Together, these results highlight an important role of UL11 in the acquisition of glycoprotein-enriched lipid bilayers, and the findings may also have important implications for the role of UL11 in gE-mediated cell-to-cell spread.

Variations in Spike Glycoprotein Gene of MERS-CoV, South Korea, 2015.

Science.gov (United States)

Kim, Dae-Won; Kim, You-Jin; Park, Sung Han; Yun, Mi-Ran; Yang, Jeong-Sun; Kang, Hae Ji; Han, Young Woo; Lee, Han Saem; Kim, Heui Man; Kim, Hak; Kim, A-Reum; Heo, Deok Rim; Kim, Su Jin; Jeon, Jun Ho; Park, Deokbum; Kim, Joo Ae; Cheong, Hyang-Min; Nam, Jeong-Gu; Kim, Kisoon; Kim, Sung Soon

2016-01-01

An outbreak of nosocomial infections with Middle East respiratory syndrome coronavirus occurred in South Korea in May 2015. Spike glycoprotein genes of virus strains from South Korea were closely related to those of strains from Riyadh, Saudi Arabia. However, virus strains from South Korea showed strain-specific variations.

Two lectin-like receptors for alpha 1-acid glycoprotein in mouse testis

DEFF Research Database (Denmark)

Andersen, U O; Kirkeby, S; Bøg-Hansen, T C

1997-01-01

Three glycoforms of alpha 1-acid glycoprotein (AGP) were biotinylated to examine their binding in mouse testis by light microscopy. The transition from one stage to another in the spermatogenic cycle is marked with an appearance of a receptor for the Concanavalin A (Con A) non-reactive glycoform...

Reappraisal of bicarbonate secretion by the human oesophagus

DEFF Research Database (Denmark)

Mertz-Nielsen, A; Hillingsø, J; Bukhave, Klaus

1997-01-01

BACKGROUND AND AIMS: Administration of omeprazole to healthy volunteers was recently reported to increase proximal duodenal mucosalbicarbonate secretion. As human oesophagus also secretes bicarbonate, the hypothesis was tested that omeprazole may stimulate oesophagealbicarbonate secretion and thus......: The median rates (95% confidence intervals)of intrinsic oesophageal bicarbonate secretion, corrected for contaminating salivary and gastric bicarbonate, were 89 (33-150) and 121 (63-203)mumol/h/10 cm (p > 0.5) in omeprazole and ranitidine treated subjects respectively. Salivary and gastric bicarbonate...... be overestimated. As omeprazole and ranitidine did not affect bicarbonate secretion differently there was no evidence that omeprazole acts on icarbonate secretory cells in the oesophageal mucosa....

Indomethacin decreases gastroduodenal mucosal bicarbonate secretion in humans

DEFF Research Database (Denmark)

Mertz-Nielsen, A; Hillingsø, Jens; Bukhave, K

1995-01-01

BACKGROUND: Cyclooxygenase inhibitors reduce mucosal bicarbonate secretion in the duodenum, but the evidence for their effect on bicarbonate secretion in the stomach remains controversial. We have, therefore, studied how indomethacin influences gastroduodenal bicarbonate secretion and luminal...... healthy volunteers. Bicarbonate and PGE2 were measured in the gastroduodenal effluents by back-titration and radioimmunoassay, respectively. RESULTS: Vagal stimulation and duodenal luminal acidification (0.1 M HCl; 20 ml; 5 min) increased gastroduodenal bicarbonate secretion (p ... markedly inhibited both basal and stimulated gastric and duodenal mucosal bicarbonate secretion, and this reduction was similar to the degree of cyclooxygenase inhibition estimated by the luminal release of PGE2 (p

Modification-specific proteomic analysis of glycoproteins in human body fluids by mass spectrometry

DEFF Research Database (Denmark)

Bunkenborg, Jakob; Hägglund, Per; Jensen, Ole Nørregaard

2007-01-01

-glycosylated proteins in body fluids and other complex samples. An approach for identification of N-glycosylated proteins and mapping of their glycosylation sites is described. In this approach, glycoproteins are initially selectively purified by lectin chromatography. Following tryptic digestion, glycopeptides...

[Secret drug tribulations and French legislation].

Science.gov (United States)

Charlot, Colette

2002-01-01

From an official Montpellier prefecture paper of 18th century, we are interested in a secret drug from Provence origin: the Irroë powder. This purgative will pass from "secret" drug status to "patent" drug. It's notoriety will come from its arrival to Paris. The law of 21th germinal year XI, the decret of 25 prairial year XIII and this of 18th 1810 imposed to give the drug composition to an official status; that examined and permit it's sale. This secret will be produce for half century.

Interaction of a novel Tn (GalNAc alpha 1-->Ser/Thr) glycoprotein with Gal, GalNAc and GlcNAc specific lectins.

Science.gov (United States)

Wu, A M; Wu, J H; Shen, F

1994-01-14

A naturally occurring Tn glycoprotein (Native ASG-Tn) with GalNAc alpha 1-->Ser/Thr as the only carbohydrate side chains, has been prepared from armadillo submandibular glands. In a quantitative precipitin assay, this glycoprotein completely precipitated Maclura pomifera (MPA), Vicia villosa B4 (VVL-B4) and Artocarpus integrifolia (Jacalin, AIL). It also reacted well with Helix pomatia (HPL) and Wistaria floribunda (WFL) and precipitated over 75% of the lectin nitrogen added, but poorly with Ricinus communis agglutinin (RCA1), ricin, peanut (Arachis hypogaea, PNA), Abrus precatorius agglutinin (APA) and Triticum vulgaris (WGA). This finding suggests that this novel Tn-glycoprotein may serve as a useful reagent for differentiating Tn and T specific monoclonal antibodies and lectins.

Ductal Mucus Obstruction and Reduced Fluid Secretion Are Early Defects in Chronic Pancreatitis

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Anita Balázs

2018-05-01

Full Text Available Objective: Defective mucus production in the pancreas may be an important factor in the initiation and progression of chronic pancreatitis (CP, therefore we aimed to (i investigate the qualitative and quantitative changes of mucus both in human CP and in an experimental pancreatitis model and (ii to correlate the mucus phenotype with epithelial ion transport function.Design: Utilizing human tissue samples and a murine model of cerulein induced CP we measured pancreatic ductal mucus content by morphometric analysis and the relative expression of different mucins in health and disease. Pancreatic fluid secretion in CP model was measured in vivo by magnetic resonance cholangiopancreatography (MRCP and in vitro on cultured pancreatic ducts. Time-changes of ductal secretory function were correlated to those of the mucin production.Results: We demonstrate increased mucus content in the small pancreatic ducts in CP. Secretory mucins MUC6 and MUC5B were upregulated in human, Muc6 in mouse CP. In vivo and in vitro fluid secretion was decreased in cerulein-induced CP. Analysis of time-course changes showed that impaired ductal ion transport is paralleled by increased Muc6 expression.Conclusion: Mucus accumulation in the small ducts is a combined effect of mucus hypersecretion and epithelial fluid secretion defect, which may lead to ductal obstruction. These results suggest that imbalance of mucus homeostasis may have an important role in the early-phase development of CP, which may have novel diagnostic and therapeutic implications.

SECURE VISUAL SECRET SHARING BASED ON DISCRETE WAVELET TRANSFORM

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S. Jyothi Lekshmi

2015-08-01

Full Text Available Visual Cryptography Scheme (VCS is an encryption method to encode secret written materials. This method converts the secret written material into an image. Then encode this secret image into n shadow images called shares. For the recreation of the original secret, all or some selected subsets of shares are needed; individual shares are of no use on their own. The secret image can be recovered simply by selecting some subset of these n shares, makes transparencies of them and stacking on top of each other. Nowadays, the data security has an important role. The shares can be altered by an attacker. So providing security to the shares is important. This paper proposes a method of adding security to cryptographic shares. This method uses two dimensional discrete wavelet transform to hide visual secret shares. Then the hidden secrets are distributed among participants through the internet. All hidden shares are extracted to reconstruct the secret.

On Secret Sharing with Nonlinear Product Reconstruction

DEFF Research Database (Denmark)

Cascudo Pueyo, Ignacio; Cramer, Ronald; Mirandola, Diego

2015-01-01

Multiplicative linear secret sharing is a fundamental notion in the area of secure multiparty computation and, since recently, in the area of two-party cryptography as well. In a nutshell, this notion guarantees that the product of two secrets is obtained as a linear function of the vector......-necessarily-linear “product reconstruction function.” Is the resulting notion equivalent to multiplicative linear secret sharing? We show the (perhaps somewhat counterintuitive) result that this relaxed notion is strictly more general. Concretely, fix a finite field ${\\mathbb F}_q$ as the base field over which linear secret...... sharing is considered. Then we show there exists an (exotic) linear secret sharing scheme with an unbounded number of players $n$ such that it has $t$-privacy with $t = \\Omega(n)$ and such that it does admit a product reconstruction function, yet this function is necessarily nonlinear. In addition, we...

Reelin secreted by GABAergic neurons regulates glutamate receptor homeostasis.

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Cecilia Gonzalez Campo

Full Text Available BACKGROUND: Reelin is a large secreted protein of the extracellular matrix that has been proposed to participate to the etiology of schizophrenia. During development, reelin is crucial for the correct cytoarchitecture of laminated brain structures and is produced by a subset of neurons named Cajal-Retzius. After birth, most of these cells degenerate and reelin expression persists in postnatal and adult brain. The phenotype of neurons that bind secreted reelin and whether the continuous secretion of reelin is required for physiological functions at postnatal stages remain unknown. METHODOLOGY/PRINCIPAL FINDINGS: Combining immunocytochemical and pharmacological approaches, we first report that two distinct patterns of reelin expression are present in cultured hippocampal neurons. We show that in hippocampal cultures, reelin is secreted by GABAergic neurons displaying an intense reelin immunoreactivity (IR. We demonstrate that secreted reelin binds to receptors of the lipoprotein family on neurons with a punctate reelin IR. Secondly, using calcium imaging techniques, we examined the physiological consequences of reelin secretion blockade. Blocking protein secretion rapidly and reversibly changes the subunit composition of N-methyl-D-aspartate glutamate receptors (NMDARs to a predominance of NR2B-containing NMDARs. Addition of recombinant or endogenously secreted reelin rescues the effects of protein secretion blockade and reverts the fraction of NR2B-containing NMDARs to control levels. Therefore, the continuous secretion of reelin is necessary to control the subunit composition of NMDARs in hippocampal neurons. CONCLUSIONS/SIGNIFICANCE: Our data show that the heterogeneity of reelin immunoreactivity correlates with distinct functional populations: neurons synthesizing and secreting reelin and/or neurons binding reelin. Furthermore, we show that continuous reelin secretion is a strict requirement to maintain the composition of NMDARs. We propose

Melatonin Secretion Pattern in Critically Ill Patients

DEFF Research Database (Denmark)

Boyko, Yuliya; Holst, René; Jennum, Poul

2017-01-01

effect of remifentanil on melatonin secretion. We found that the risk of atypical sleep compared to normal sleep was significantly lower (p REM) sleep was only observed during the nonsedation period. We found preserved diurnal pattern of melatonin...... secretion in these patients. Remifentanil did not affect melatonin secretion but was associated with lower risk of atypical sleep pattern. REM sleep was only registered during the period of nonsedation.......Critically ill patients have abnormal circadian and sleep homeostasis. This may be associated with higher morbidity and mortality. The aims of this pilot study were (1) to describe melatonin secretion in conscious critically ill mechanically ventilated patients and (2) to describe whether melatonin...

Thymidine secretion by hybridoma and myeloma cells

International Nuclear Information System (INIS)

Spilsberg, Bjorn; Rise, Frode; Petersen, Dirk; Nissen-Meyer, Jon

2006-01-01

Secretion of thymidine appeared to be a common property of hybridoma and myeloma cells, but not of other cell types, which were tested. Of three hybridoma cell lines tested, all secreted thymidine in amounts resulting in the accumulation of thymidine to concentrations of 10-20 μM in the culture medium. Also three of five myeloma cell lines that were analyzed secrete thymidine, but none of the other cell types that were studied. Thymidine was purified to homogeneity (4 mg purified from 3 l of culture medium) and identified as such by nuclear magnetic resonance spectroscopy. The cells that secreted thymidine showed high resistance to the growth inhibitory effect of thymidine

Acute radiation effects on saliva composition in rats with different vitamin a levels in serum

Energy Technology Data Exchange (ETDEWEB)

Funegard, U; Johansson, I; Franzen, L; Ericson, T [Dept. of Cardiology, Univ. Umeaa (Sweden) Dept. of Oncology, Univ. Umeaa (Sweden)

1991-01-01

Irradiation of the head and neck often causes loss of salivary gland function which may lead to severe oral discomfort. The effects of a single dose of 25 Gy given to rats with different serum levels of vitamin A were studied. The salivary secretion rate as well as concentrations of protein, hexosamine, amylase and electrolytes, and the activities of two antibacterial glycoproteins were measured. At an adequates of two antibacterial glycoproteins were measured. At an adequate level of vitamin A in the diet, irradiation significantly reduced whole saliva secretion rate, and decreased the concentration of salivary sodium, calcium and hexosamine as well as the activity of a glycoprotein agglutinating a serotype c strain of S. mutans. Peroxidase, amylase and potassium were not significantly affected. The reductions seen at an adequate level of vitamin A were not reduced by supplementation of excess dietary retinol. The damage caused by irradiation was enhanced by vitamin A deficiency as seen in the reduced protein and hexosamine concentrations. (orig.).

Acute radiation effects on saliva composition in rats with different vitamin a levels in serum

International Nuclear Information System (INIS)

Funegard, U.; Johansson, I.; Franzen, L.; Ericson, T.

1991-01-01

Irradiation of the head and neck often causes loss of salivary gland function which may lead to severe oral discomfort. The effects of a single dose of 25 Gy given to rats with different serum levels of vitamin A were studied. The salivary secretion rate as well as concentrations of protein, hexosamine, amylase and electrolytes, and the activities of two antibacterial glycoproteins were measured. At an adequates of two antibacterial glycoproteins were measured. At an adequate level of vitamin A in the diet, irradiation significantly reduced whole saliva secretion rate, and decreased the concentration of salivary sodium, calcium and hexosamine as well as the activity of a glycoprotein agglutinating a serotype c strain of S. mutans. Peroxidase, amylase and potassium were not significantly affected. The reductions seen at an adequate level of vitamin A were not reduced by supplementation of excess dietary retinol. The damage caused by irradiation was enhanced by vitamin A deficiency as seen in the reduced protein and hexosamine concentrations. (orig.)

Carbohydrates of influenza virus. I. Glycopeptides derived from viral glycoproteins after labeling with radioactive sugars

International Nuclear Information System (INIS)

Schwarz, R.T.; Schmidt, M.F.G.; Anwer, U.; Klenk, H.D.

1977-01-01

The carbohydrate moiety of the influenza glycoproteins NA, HA 1 , and HA 2 were analyzed by labeling with radioactive sugars. Analysis of glycopeptides obtained after digestion with Pronase indicated that there are at least two different types of carbohydrate side chains. The side chain of type I is composed of glucosamine, mannose, galactose, and fucose. It is found on NA, HA 1 , and HA 2 . The side chain of type II contains a high amount of mannose and is found only on NA and HA 2 . The molecular weights of the corresponding glycopeptides obtained from virus grown in chicken ambryo cells are 2,600 for type I and 2,000 for type II. The glycoproteins of virus grown in MDBK cells have a higher molecular weight than those of virus grown in chicken embryo cells, and there is a corresponding difference in the molecular weights of the glycopeptides. Under conditions of partial inhibition of glycosylation, virus particles were isolated that contained hemagglutinin with reduced carbohydrate content. Glycopeptide analysis indicated that this reduction is due to the lack of whole carbohydrate side chains and not to the incorporation of incomplete ones. This observation suggests that glycosylation of the viral glycoproteins involves en bloc transfer of the core sugars to the polypeptide chains

Intermittent subglottic secretion drainage may cause tracheal damage in patients with few oropharyngeal secretions.

Science.gov (United States)

Suys, E; Nieboer, K; Stiers, W; De Regt, J; Huyghens, L; Spapen, H

2013-12-01

Injurious prolapse of tracheal mucosa into the suction port has been reported in up to 50% of intubated patients receiving continuous aspiration of subglottic secretions. We investigated whether similar injury could be inflicted by automated intermittent aspiration. Six consecutive patients, intubated with the Mallinckrodt TaperGuard Evac™ endotracheal tube, were studied. A flow sensor was placed between the vacuum regulating system and the mucus collector. Intermittent suctioning was performed at a pressure of -125 mmHg with a 25s interval and duration of 15s. After 24h, a CT scan of the tracheal region was performed. Excessive negative suction pressure, a fast drop in aspiration flow to zero, and important "swinging" movements of secretions in the evacuation line were observed in all patients. Oral instillation of antiseptic mouthwash restored normal aspiration flow and secretion mobility. CT imaging showed marked entrapment of tracheal mucosa into the suction port in all patients. In patients with few oropharyngeal secretions, automated intermittent subglottic aspiration may result in significant and potential harmful invagination of tracheal mucosa into the suction lumen. A critical amount of fluid must be present in the oropharynx to assure adequate and safe aspiration. Copyright © 2013 Elsevier Ltd. All rights reserved.

Sagnac secret sharing over telecom fiber networks.

Science.gov (United States)

Bogdanski, Jan; Ahrens, Johan; Bourennane, Mohamed

2009-01-19

We report the first Sagnac quantum secret sharing (in three-and four-party implementations) over 1550 nm single mode fiber (SMF) networks, using a single qubit protocol with phase encoding. Our secret sharing experiment has been based on a single qubit protocol, which has opened the door to practical secret sharing implementation over fiber telecom channels and in free-space. The previous quantum secret sharing proposals were based on multiparticle entangled states, difficult in the practical implementation and not scalable. Our experimental data in the three-party implementation show stable (in regards to birefringence drift) quantum secret sharing transmissions at the total Sagnac transmission loop distances of 55-75 km with the quantum bit error rates (QBER) of 2.3-2.4% for the mean photon number micro?= 0.1 and 1.7-2.1% for micro= 0.3. In the four-party case we have achieved quantum secret sharing transmissions at the total Sagnac transmission loop distances of 45-55 km with the quantum bit error rates (QBER) of 3.0-3.7% for the mean photon number micro= 0.1 and 1.8-3.0% for micro?= 0.3. The stability of quantum transmission has been achieved thanks to our new concept for compensation of SMF birefringence effects in Sagnac, based on a polarization control system and a polarization insensitive phase modulator. The measurement results have showed feasibility of quantum secret sharing over telecom fiber networks in Sagnac configuration, using standard fiber telecom components.

Analysis of secreted proteins from Aspergillus flavus.

Science.gov (United States)

Medina, Martha L; Haynes, Paul A; Breci, Linda; Francisco, Wilson A

2005-08-01

MS/MS techniques in proteomics make possible the identification of proteins from organisms with little or no genome sequence information available. Peptide sequences are obtained from tandem mass spectra by matching peptide mass and fragmentation information to protein sequence information from related organisms, including unannotated genome sequence data. This peptide identification data can then be grouped and reconstructed into protein data. In this study, we have used this approach to study protein secretion by Aspergillus flavus, a filamentous fungus for which very little genome sequence information is available. A. flavus is capable of degrading the flavonoid rutin (quercetin 3-O-glycoside), as the only source of carbon via an extracellular enzyme system. In this continuing study, a proteomic analysis was used to identify secreted proteins from A. flavus when grown on rutin. The growth media glucose and potato dextrose were used to identify differentially expressed secreted proteins. The secreted proteins were analyzed by 1- and 2-DE and MS/MS. A total of 51 unique A. flavus secreted proteins were identified from the three growth conditions. Ten proteins were unique to rutin-, five to glucose- and one to potato dextrose-grown A. flavus. Sixteen secreted proteins were common to all three media. Fourteen identifications were of hypothetical proteins or proteins of unknown functions. To our knowledge, this is the first extensive proteomic study conducted to identify the secreted proteins from a filamentous fungus.

Secret-key rates and privacy leakage in biometric systems

NARCIS (Netherlands)

Ignatenko, T.

2009-01-01

In this thesis both the generation of secret keys from biometric data and the binding of secret keys to biometric data are investigated. These secret keys can be used to regulate access to sensitive data, services, and environments. In a biometric secrecy system a secret key is generated or chosen