• Title/Summary/Keyword: Glycoprotein B

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Inhibitory Effects of Euchrestaflavone B on Thrombus Formation via Regulation of Cyclic Nucleotides in Collagen-induced Platelets (콜라겐 유도의 혈소판에서 사이클릭 뉴클레오티드의 조절을 통한 Euchrestaflavone B의 혈전 형성 억제 효과)

  • Kwon, Hyuk-Woo
    • Korean Journal of Pharmacognosy
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    • v.51 no.4
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    • pp.231-237
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    • 2020
  • Euchrestaflavanone B (EFB) is a flavonoid that can be found in root bark, particularly in Cudrania tricuspidata (C. tricuspidata). The extract of C. tricuspidata is widespread throughout Asia and used in traditional medicine. In a previous study, we found anti-platelet effects of substances isolated from C. tricuspidata on collagen-induced human platelets. However, the C. tricuspidata still contains numerous substances, thus, we have searched new candidate, EFB isolated from C. tricuspidata for anti-platelet effect. Our results showed that EFA inhibited collagen-induced platelet aggregation and glycoprotein IIb/IIIa (αIIb/β3)-mediated signaling events, including platelet adhesion, granule secretion, thromboxane A2 production and clot retraction. These results suggest that EFA has inhibitory effects on human platelet activities and thrombus formation and has potential value as a natural substance for preventing platelet-induced thrombosis.

Glycoprotein in the Fruit Body of Sarcodon aspratus (능이자실체의 Glycoprotein)

  • Cho, Nam-Seok;Choi, Tae-Ho;Cho, Hee-Yeon;Leonowicz, Andrzej
    • Journal of the Korean Wood Science and Technology
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    • v.32 no.5
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    • pp.51-58
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    • 2004
  • This study was performed to investigate compositions of inorganic elements, amino acids and glycoprotein fractions as biological substances in fruit body of Sarcodon aspratus. The fruit body of Sarcodon aspratus contained Ca, Mg, Zn, Mn, Fe, Cu, and Pb, in particular high Ca and Na. Hot water extracts consisted of 54% of polysaccharide fraction and 32.6% of protein. In amino acids composition, fourteen free amino acids were detected, mainly glutamic acid, alanine and arginine. Fifteen kinds of total amino acids were contained with major components of glutamic acid, aspartic acid, serine and threonine. Concerned to glycoprotein extraction, 95% ethyl alcohol concentration gave the highest yields with 70.6% sugar fraction, 332% glycoprotein. Different ethyl alcohol concentration resulted in different protein precipitations, and lower concentration ethyl alcohol in the range of 30 to 70% gave more than 92% of higher sugar fraction. Crude glycoprotein (GP) was fractionated by P fraction of more than MW 300,000, P-1 fraction unadsorbed by DEAE-Sephadex, P-2 fractionated from P-1 by Sepharose 2B gel chromatography and P-3 fraction adsorbed by DEAE-Sephadex. Total sugars were increased and protein contents decreased during fractionation. GP and P-3 contained glucose, galactose, mannose and fucose. GP had high glucose with high contents of glutamic acid, serine, alanine and glycine. P-3 fraction contained high mannose with aspartic acid, glutamic acid, and glycine. P-2 fraction was 700,000 MW with high glucose and fucose, and low protein of 1.1%, high amounts of aspartic acid, glutamic acid and alanine, but no mannose and no cysteine.

Protein Binding of Disopyramide -Displacement by Mono-N-Dealkyl-Disopyramide and Variation with Commerial Source of Alpha-1-Acid Glycoprotein-

  • Haughey, David B.;Steinberg, Irving;Lee, Min-Hwa
    • Journal of Pharmaceutical Investigation
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    • v.15 no.1
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    • pp.1-7
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    • 1985
  • Previous studies show that the free (unbound) fraction of disopyramide in human serum is drug concentration dependent~ at corresponding serum disopyramide concentrations that are achieved clinically. $^1^{\sim}^3^)\;Moreover$, disopyramide free fraction values vary several fold at any given drug concentration in human serum and tend to decrease as serum cocentrations of alpha-I-acid glycoprotein(AAG) incrase.$^4^)$ A recent $study^5^)$ demonstrates that the free fraction of disopyramide inhuman serum increases almost 2-fold following the addition of $14.4{\mu}M/L$ mono-N-dealkyldisopyramide. These studies and others. $^6^),\;^7^)$ prompted the present investigation to characterize the protein binding of disopyramide in human serum and solutions of AAG in the presence of mono-N-dealkyldisopyramide (a major metabolite of, disopyramide) and to determine the utility of using commercially available alpha-I-acid glycoprotein for drug protein binding displacement studies. Because many basic and acidic compounds are known to bind to alpha-I-acid $glycoprotein^8^)$ the present study. was performed to determine whteher commercially available AAG would provide a convenient protein source for such binding studies.

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Sequencing and Baculovirus-Based Expression of the Glycoprotein B2 Gene of HSV-2 (G)

  • Uh, Hong-Sun;Park, Jong-Kuk;Kang, Hyun;Kim, Soo-Young;Lee, Hyung-Hoan
    • Journal of Microbiology and Biotechnology
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    • v.11 no.3
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    • pp.482-490
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    • 2001
  • The gene for glycoprotein B (gB2) of HSV-2-strain G was subcloned, sequenced, recombinated into the lacZ-HcNPV, expressed in insect cells, and compared with the homologous gene of other HSV-2 strains. The ORF of the gB2 gene was 2,715 bp. The overall nucleotide sequence homology of te gB2 gene compared ith that of the two previously reported HSV-2 strains appeared to be over 98%. A recombinant virus named Baculo-gB2 protein in insect cells. The recombination was confirmed by a PCR and the expression was demonstrated by radio immunoprecipitation. Insect cells infected with the Baculo-gB2 virus synthesized and processed gB2 with approximately 120 kDa in the cells, and then secreted it into the culture media, where it reacted with a nomoclonal antibody to gB2. The gB2 polypeptide contained two main hydrophobic regions (a signal sequence from 1 to 23 amino acid residues, and a membrane anchor sequence from aa 745 to 798), eight N-glycosylation sites evenly distributed, and was rich in alanine (11.2%). Antibodies to this recombinant protein that were raised in mice recognized the viral gB2 and neutralized the infectivity of the HSV-2 in vitro. There results show that the gB2 protein was successfully porduced in insect cells and could be used to raise a protective neutralizing antibody. Accordingly, this particular recombinant protein may be useful in the development of a subunit vaccine.

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Autophagy-Dependent Survival of Mutant B-Raf Melanoma Cells Selected for Resistance to Apoptosis Induced by Inhibitors against Oncogenic B-Raf

  • Ahn, Jun-Ho;Lee, Michael
    • Biomolecules & Therapeutics
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    • v.21 no.2
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    • pp.114-120
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    • 2013
  • Most patients with mutant B-Raf melanomas respond to inhibitors of oncogenic B-Raf but resistance eventually emerges. To better understand the mechanisms that determine the long-term responses of mutant B-Raf melanoma cells to B-Raf inhibitor, we used chronic selection to establish B-Raf (V600E) melanoma clones with acquired resistance to the new oncogenic B-Raf inhibitor UI-152. Whereas the parental A375P cells were highly sensitive to UI-152 ($IC_{50}$ < $0.5{\mu}M$), the resistant sub-line (A375P/Mdr) displayed strong resistance to UI-152 ($IC_{50}$ < $20{\mu}M$). Immunofluorescence analysis indicated the absence of an increase in the levels of P-glycoprotein multidrug resistance (MDR) transporter in A375P/Mdr cells, suggesting that resistance was not attributable to P-glycoprotein overexpression. In UI-152-sensitive A375P cells, the anti-proliferative activity of UI-152 appeared to be due to cell-cycle arrest at $G_0/G_1$ with the induction of apoptosis. However, we found that A375P/Mdr cells were resistant to the apoptosis induced by UI-152. Interestingly, UI-152 preferentially induced autophagy in A375P/Mdr cells but not in A375P cells, as determined by GFP-LC3 puncta/cell counts. Further, autophagy inhibition with 3-methyladenine (3-MA) partially augmented growth inhibition of A375P/Mdr cells by UI-152, which implies that a high level of autophagy may protect UI-152-treated cells from undergoing growth inhibition. Together, our data implicate high rates of autophagy as a key mechanism of acquired resistance to the oncogenic B-Raf inhibitor, in support of clinical studies in which combination therapy with autophagy targeted drugs is being designed to overcome resistance.

Cytochalasin B Modulates Macrophage-Mediated Inflammatory Responses

  • Kim, Mi-Yeon;Kim, Jong-Hoon;Cho, Jae Youl
    • Biomolecules & Therapeutics
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    • v.22 no.4
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    • pp.295-300
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    • 2014
  • The actin cytoskeleton plays an important role in macrophage-mediated inflammatory responses by modulating the activation of Src and subsequently inducing nuclear factor (NF)-${\kappa}B$ translocation. In spite of its critical functions, few papers have examined how the actin cytoskeleton can be regulated by the activation of toll-like receptor (TLR). Therefore, in this study, we further characterized the biological value of the actin cytoskeleton in the functional activation of macrophages using an actin cytoskeleton disruptor, cytochalasin B (Cyto B), and explored the actin cytoskeleton's involvement in morphological changes, cellular attachment, and signaling events. Cyto B strongly suppressed the TLR4-mediated mRNA expression of inflammatory genes such as cyclooxygenase (COX)-2, tumor necrosis factor (TNF)-${\alpha}$, and inducible nitric oxide (iNOS), without altering cell viability. This compound also strongly suppressed the morphological changes induced by lipopolysaccharide (LPS), a TLR4 ligand. Cyto B also remarkably suppressed NO production under non-adherent conditions but not in an adherent environment. Cyto B did not block the co-localization between surface glycoprotein myeloid differentiation protein-2 (MD2), a LPS signaling glycoprotein, and the actin cytoskeleton under LPS conditions. Interestingly, Cyto B and PP2, a Src inhibitor, enhanced the phagocytic uptake of fluorescein isothiocyanate (FITC)-dextran. Finally, it was found that Cyto B blocked the phosphorylation of vasodilator-stimulated phosphoprotein (VASP) at 1 min and the phosphorylation of heat shock protein 27 (HSP27) at 5 min. Therefore, our data suggest that the actin cytoskeleton may be one of the key components involved in the control of TLR4-mediated inflammatory responses in macrophages.

Detection of Glycoproteins (B and D) and Thymidine Kinase Genes of Herpes simplex virus Type 2 Strain G

  • Kang, Hyun;Park, Jong-Kuk;Uh, Hong-Sun;Kim, Soo-Young;Lee, Hyung-Hoan
    • The Journal of Korean Society of Virology
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    • v.29 no.2
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    • pp.99-105
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    • 1999
  • BamHI restriction pattern and genomic library of Herpes simplex virus type 2 (HSV-2) strain G were constructed, and locations of the glycoproteins gB and gD, and tk genes on the fragments were detected by Southern blot analysis. HSV-2 genomic DNAs were cleaved into twenty-seven fragments by BamHI enzyme in the range of 0.72 to 15.08 (total 150.44 kb), which were cloned into the BamHI site of pBluescript SK(+) to construct genome library of the HSV-2. The library was named by the order of the fragment size from smallest one to largest one. HSV-2 glycoprotein gD gene was located in pHLA2-21 and pHLA2-22 recombinant plasmids, gB gene in pHLA2-24 plasmid, and tk gene in pHLA2-11 clone by Southern blot analysis.

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Nasal Immunization Using Chitosan Nanoparticles with Glycoprotein B of Murine Cytomegalovirus

  • Marcela Slovakova;Sylva Janovska;Radek Sleha;Vera Radochova;Alexandra Hatala;Nikola Mannova;Radovan Metelka;Ludovit Pudelka;Pavel Bostik
    • Journal of Microbiology and Biotechnology
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    • v.34 no.3
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    • pp.663-672
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    • 2024
  • The use of nanoparticles as a delivery system for a specific antigen could solve many limitations of mucosal vaccine applications, such as low immunogenicity, or antigen protection and stabilization. In this study, we tested the ability of nasally administered chitosan nanoparticles loaded with glycoprotein B of murine cytomegalovirus to induce an immune response in an animal model. The choice of chitosan nanoparticle type was made by in vitro evaluation of sorption efficiency and antigen release. Three types of chitosan nanoparticles were prepared: crosslinked with tripolyphosphate, coated with hyaluronic acid, and in complex with polycaprolactone. The hydrodynamic size of the nanoparticles by dynamic light scattering, zeta potential, Fourier transform infrared spectroscopy, scanning electron microscopy, stability, loading efficiency, and release kinetics with ovalbumin were evaluated. Balb/c mice were immunized intranasally using the three-dose protocol with nanoparticles, gB, and adjuvants Poly(I:C) and CpG ODN. Subsequently, the humoral and cell-mediated antigen-specific immune response was determined. On the basis of the properties of the tested nanoparticles, the cross-linked nanoparticles were considered optimal for further investigation. The results show that nanoparticles with Poly(I:C) and with gB alone raised IgG antibody levels above the negative control. In the case of mucosal IgA, only gB alone weakly induced the production of IgA antibodies compared to saline-immunized mice. The number of activated cells increased slightly in mice immunized with nanoparticles and gB compared to those immunized with gB alone or to negative control. The results demonstrated that chitosan nanoparticles could have potential in the development of mucosal vaccines.

Oviduct-specific Glycoprotein 1 Locus is Associated with Litter Size and Weight of Ovaries in Pigs

  • Niu, B.Y.;Xiong, Y.Z.;Li, F.E.;Jiang, S.W.;Deng, C.Y.;Ding, S.H.;Guo, W.H.;Lei, M.G.;Zheng, R.;Zuo, B.;Xu, D.Q.;Li, J.L.
    • Asian-Australasian Journal of Animal Sciences
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    • v.19 no.5
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    • pp.632-637
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    • 2006
  • Oviduct-specific glycoprotein 1 (OVGP1) is implicated in playing a role in fertilization and early embryo development. In this study, we have obtained the sequence of intron 9 of OVGP1 gene in swine. Comparative sequencing of Meishan (a native Chinese breed) and Large White pig breeds revealed an A/T substitution at position 943. A PCR-EcoRI-RFLP assay was developed to detect this mutation. Polymorphism analysis in Qingping animals showed that pigs with BB genotype had lower number of piglets born alive (NBA) in multiple parities than pigs with AA (p<0.05) and AB genotype (p<0.01). In Large $White{\times}Meishan$ ($LW{\times}M$) $F_2$ offspring, the weight of both ovaries (OW) of the BB genotype was significantly lighter than that of AB (p = 0.05) and AA (p<0.01) genotypes. Analysis of the data also revealed that the mutation locus affected these two traits mostly by additive effects. These studies indicated that the polymorphism was associated with NBA and OW in two distinct populations and further investigations in more purebreds or crossbreds are needed to confirm these results.

Characterization and Immunopotentiating Effects of the Glycoprotein Isolated from Dioscorea Batatas

  • Huong, Pham Thi Thu;Lee, Chan-Ho;Li, Mei-Hong;Lee, Min-Young;Kim, Joon-Ki;Lee, Sun-Mee;Seon, Jong-Heum;Lee, Dong-Cheol;Jeon, Young-Jin
    • The Korean Journal of Physiology and Pharmacology
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    • v.15 no.2
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    • pp.101-106
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    • 2011
  • We demonstrate that glycoprotein isolated from Dioscorea batatas (GDB) has immunostimulatory effects including macrophage activation. Analysis of infiltration of inflammatory cells into peritoneal cavity showed GDB treatment significantly increased the recruitment of macrophages, lymphocytes, neutrophils, and monocytes into the peritoneal cavity. Treatment of spleen cells isolated from C57BL/6 mice with GDB significantly increased the proliferation of B cells and T cells induced by LPS and ConA, respectively. Treatment with GDB significantly increased the cytolytic capacity of NK cells and macrophages against YAC-1 and B16 cells, respectively. In order to further confirm and investigate the mechanism of GDB on macrophage activation, we analyzed the effects of GDB on the cytokine expression including iNOS, IL-1${\beta}$, and TNF-${\alpha}$ in mouse macrophage cell line, RAW 264.7 cells. RT-PCR and ELISA showed that GDB increased the expression of IL-1${\beta}$, and TNF-${\alpha}$, whereas iNOS was not induced by GDB. Collectively, this series of experiments indicates that GDB stimulates immune system including macrophage activation.