• Toxicological Research
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• v.8 no.2
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• pp.343-357
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• 1992

Tumor necrosis factor-${\alpha}$(TNF), a polypeptide hormone secreted primarily by activated macrophages, was originally identified on the basis of its ability to cause hemorrhagic necrosis and tumor regression in vivo. Subsequently, TNF has been shown to be an important component of the host responses to infection and cancer and may mediate the wasting syndrome known as cachexia. These systemic actions of TNF are reflected in its diverse effects on target cells in vitro. TNF initiates its diverse cellular actions by binding to specific cell surface receptors. Although TNF receptors have been identified on most of animal cells, regulation of these receptors and the mechanisms which transduce TNF receptor binding into cellular responses are not well understood. Therefore, in the present study, the mechanisms how TNF receptors are being regulated and how TNF receptor binding is being transduced into cellular responses were investigated in rat liver plasma membranes (PM) and ME-180 human cervical carcinoma cell lines. $^{125}I$-TNF bound to high ($K_d=1.51{\pm}0.35nM$)affinity receptors in rat liver PM. Solubilization of PM with 1% Triton X-100 increased both high affinity (from $0.33{\pm}0.04\;to\;1.67{\pm}0.05$ pmoles/mg protein) and low affinity (from $1.92{\pm}0.16\;to\;7.57{\pm}0.50$ pmoles/mg protein) TNF binding without affecting the affinities for TNF, suggesting the presence of a large latent pool of TNF receptors. Affinity labeling of receptors whether from PM or solubilized PM resulted in cross-linking of $^{125}I$-TNF into $M_r$ 130 kDa, 90 kDa and 66kDa complexes. Thus, the properties of the latent TNF receptors were similar to those initially accessible to TNF. To determine if exposure of latent receptors is regulated by TNF, $^{125}I$-TNF binding to control and TNF-pretreated membranes were assayed. Specific binding was increased by pretreatment with TNF (P<0.05), demonstrating that hepatic PM contains latent TNF receptors whose exposure is promoted by TNF. Homologous up-regulation of TNF receptors may, in part, be responsible for sustained hepatic responsiveness during chronic exposure to TNF. As a next step, the post-receptor events induced by TNF were examined. Although the signal transduction pathways for TNF have not been delineated clearly, the actions of many other hormones are mediated by the reversible phosphorylation of specific enzymes or target proteins. The present study demonstrated that TNF induces phosphorylation of 28 kDa protein (p28). Two dimensional soidum dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE) resolved the 28kDa phosphoprotein into two isoforms having pIs of 6.2 and 6.1. The pIs and relative molecular weight of p28 were consistent with those of a previously characterized mRNA cap binding protein. mRNA cap binding proteins are a class of translation initiation factors that recognize the 7-methylguanosine cap structure found on the 5' end of eukaryotic mRNAs. In vitro, these proteins are defined by their specific elution from affinity columns composed of 7-methylguanosine 5'-triphosphate($m^7$GTP)-Sepharose. Affinity purification of mRNA cap binding proteins from control and TNF treated ME-180 cells proved that TNF rapidly stimulates phosphorylation of an mRNA cap binding protein. Phosphorylation occurred in several cell types that are important in vitro models of TNF action. The mRNA cap binding protein phosphorylated in response to TNF treatment was purifice, sequenced, and identified as the proto-oncogene product eukaryotic initiation factor-4E(eIF-4E). These data show that phosphorylation of a key component of the cellular translational machinery is a common early event in the diverse cellular actions of TNF.

• BMB Reports
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• v.37 no.3
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• pp.304-313
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• 2004

Three-dimensional (3D) models for the 65-kDa activated Cry4A and Cry4B $\delta$-endotoxins from Bacillus thuringiensis subsp. israelensis that are specifically toxic to mosquito-larvae were constructed by homology modeling, based on atomic coordinates of the Cry1Aa and Cry3Aa crystal structures. They were structurally similar to the known structures, both derived 3D models displayed a three-domain organization: the N-terminal domain (I) is a seven-helix bundle, while the middle and C-terminal domains are primarily comprise of anti-parallel $\beta$-sheets. Circular dichroism spectroscopy confirmed the secondary structural contents of the two homology-based Cry4 structures. A structural analysis of both Cry4 models revealed the following: (a) Residues Arg-235 and Arg-203 are located in the interhelical 5/6 loop within the domain I of Cry4A and Cry4B, respectively. Both are solvent exposed. This suggests that they are susceptible to tryptic cleavage. (b) The unique disulphide bond, together with a proline-rich region within the long loop connecting ${\alpha}4$ and ${\alpha}5$ of Cry4A, were identified. This implies their functional significance for membrane insertion. (c) Significant structural differences between both models were found within domain II that may reflect their different activity spectra. Structural insights from this molecular modeling study would therefore increase our understanding of the mechanic aspects of these two closely related mosquito-larvicidal proteins.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.8 no.2
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• pp.167-175
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• 1988

The principle objective of this study is to evaluate the fatigue behavior of structural steel components of highway bridges subjected to service stresses. The main aspects of this investigation are; 1) a measurement and statistical analysis of service stress cycles observed in highway bridge. 2) fatigue tests under equivalent constant-amplitude(CA) loading and simulated variable-amplitude(VA) loading 3) a evaluation of the fatigue behavior under VA-loading by eqivalent root mean cube (RMC) stress range. Theoretically, the RMC model is adequate in evaluation of fatigue behavior under VA-loading, because the regression coefficient (m) of crack growth rate is 3 approximately. The result of fatigue test shows that the RMC model is fitter than the current RMS model in fatigue evaluation under VA-loading. The interaction effects and sequence effects under VA-loading affect little fatigue life of structural components. As the transition rate of stress ranges is higher, the crack growth rate is higher.

• Koreanishche Zeitschrift fur Deutsche Sprachwissenschaft
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• v.3
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• pp.303-325
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• 2001

In diesem Aufsatz wird versucht, die Wortbildungsstruktur der deutschen Ableitungen zu analysieren und in QPATR zu implementieren. $Daf\"{u}r$ werden die deutschen Ableitungen in morphosyntaktischer Hinsicht betrachtet. Die Wortbildungsstruktur der Ableitungen wird durch Phrasenstrukturregeln mit den detaillierten Unterspezifikationen beschrieben, die durch Unifikation definiert sind. Es wird davon ausgegangen, $da{\ss}\;S\"{a}tze$ durch Phrasenstrukturregeln, die syntaktische Kombinierbarkeit der unmittelbaren Konstituenten definieren, zu analysieren sind. In Wortern sind auch die Regeln $f\"{u}r$ die Erzeugung und Analyse von abgeleiteten $W\"{o}rtern$ zu finden. Die Wortbildungsregln und die Phrasenstrukturregeln von $S\"{a}tzen$ haben $\"{A}hnlichkeit$ von der Form her. $Au{\ss}erdem$ kann man die mophosyntaktischen $Ph\"{a}nomene$ der Kongruenz oder die Selektionsrestriktion nicht nur auf der Satzsyntax, sondern auch auf der Wortsyntax betrachten. D.h. wenn man durch einen Parser mit Hilfe der Phrasenstrukturregeln einen Satz analysieren kann, kann man auch ein Wort aufgrund der Wortbildungsregeln parsen. Im ersten Abschnitt werden die grundlegenden Begriffe der 'unifikationsbasierten Grammatiken', $n\"{a}mlich$ die Begriffe 'Merkmalstruktur', 'Unifikation', und 'Subsumption' $eingef\"{u}hrt$. Im zweiten Abschnitt wird der QPATR - Parser vorgestellt, der aufgrund des 'PATR-II'-Formalismus in $D\"{u}sseldorf$ entwickelt worden ist. Im dritten Abschnitt werden die deutschen abgeleiteten $W\"{o}rter$ durch QPATR analysiert. Bei der Analyse der Worter wird gezeigt, wie die Left-corner-parsing-Strategie funktioniert, und Wie die spezifizierten Informationen durch Unifikation als 'Constraints' die zu kombinierenden unmittelbaren Konstituenten $beschr\"{a}nken$. Zum $Schlu{\ss}$ werden die Ergebnisse der Analyse durch Baumstruktur und Merkmalstruktur $repr\"{a}sentiert$, die durch QPATR automatisch erzeugt werden.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.530-530
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• 2000

The host defense system or immune system of all modern animals has their roots in very ancient organisms. After analyzing literature data concerning properties of invertebrates and vertebrates lectins we suggest that mechanism of mannans recognition may exist in marine invertebrates, as a universal mechanism for homeostasis maintenance and host defense, and mannan-binding lectins family of vertebrates has ancient precursor, as was shown for another S-type lectins family. We carried out the screening of mannan-binding type lectin among different species of echinoderms inhabiting in Piter the Grate Bay, the sea of Japan. As a result, the C-type lectins (SJL-32) specific for high mannose glycans was isolated from the coelomic plasma of the sea cucumbers Stichopus japonicus by ion-exchange chromatography on a DEAE-Toyopearl 650M, affinity chromatography on a mannan-Sepharose 6B and gel filtration on a Sephacryl S-200. SJL-32 is homodimer with molecular mass about 32 kDa on SDS-PAGE under non-reducing conditions. Protein part of the lectin has high conteins Asn, Glu, Ser. Hemagglutination of trypsin-treated O blood group human erythrocytes by SJL-32 was competitively inhibited by high-branched -D-mannan composed of -1,2 and -1,6 linked D-mannopyranose residues. In contrast, a variety of mono-, oligo-, and polysaccharides composed of residues of galactose and fucose showed absence or little inhibitory activities. The lectin activity strong depends on Ca2+ concentration, temperature and pH. Monospecific polyclonal antibodies were obtained to the lectin. As was shown by ELISA assay, antibodies to SJL-32 cross-reacted with human serum mannan-binding lectin. This data allows making conclusion about common antigenic determinants and structural homology of both lectins. In our opinion, SJL-32 belongs to evolutionary high conservative mannan-binding lectins (MBLs) family and takes part in the host defense against pathogenic microorganisms.

• Journal of Microbiology and Biotechnology
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• v.18 no.1
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• pp.160-166
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• 2008

A DNA fragment containing 2,079 base pairs from Bacillus circulans CGMCC 1416 was cloned using degenerate PCR and inverse PCR. An open reading frame containing 981 bp was identified that encoding 326 amino acids residues, including a putative signal peptide of 31 residues. The deduced amino acid sequence showed the highest identity (68.1%) with $endo-{\beta}-1,4-D-mannanase$ from Bacillus circulans strain K-1 of the glycoside hydrolase family 5 (GH5). The sequence encoding the mature protein was cloned into the pET-22b(+) vector and expressed in Escherichia coli as a recombinant fusion protein containing an N-terminal hexahistidine sequence. The fusion protein was purified by $Ni^{2+}$ affinity chromatography and its hexahistidine tag cleaved to yield a 31-kDa ${\beta}$-mannanase having a specific activity of 481.55U/mg. The optimal activity of the purified protein, MANB48, was at $58^{\circ}C$ and pH 7.6. The hydrolysis product on substrate locust bean gum included a monosaccharide and mainly oligosaccharides. The recombinant MANB48 may be of potential use in the feed industry.

• Journal of Microbiology and Biotechnology
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• v.15 no.5
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• pp.1125-1129
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• 2005

Cloning of a 6.6-kb BamHI digested chromosomal DNA from S. griseus IFO13350 revealed the presence of an additional gene encoding a novel trypsin-like enzyme, named SprU. The SprU protein shows a high homology ($79\%$ identity, $88\%$ similarity) with the SGT protease, which has been reported as a bacterial trypsin in the same strain. The amino acid sequence deduced from the nucleotide sequence of the sprU gene suggests that SprU is produced as a precursor consisting of an amino-terminal presequence (29 amino acid residues), prosequence (4 residues), and mature trypsin consisting of 222 amino acids with a molecular weight of 22.94 kDa and a calculated pI of 4.13. The serine, histidine, and aspartic acid residues composing the catalytic triad of typical serine proteases are also well conserved. When the trypsin activity of the SprU was spectrophotometrically measured by the enzymatic hydrolysis of the artificial chromogenic substrate, N-${alpha}$-benzoyl-DL-arginine-p-nitroanilide, the S. lividans transformant with pWHM3-U gave 3 times higher activity than that of control. When the same recombinant plasmid was introduced into S. griseus, however, the gene dosage effect was not so significant, as in the cases of other genes encoding serine proteases, such as sprA, sprB, and sprD. Although two trypsins, SprU and SGT, have a high degree of homology, the pI values, the gene dosage effect in S. griseus, and the gene arrangement adjacent to the two genes are very different, suggesting that the biochemical and biological function of the SprU might be quite different from that of the SGT.

• Korean Journal of Biological Psychiatry
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• v.18 no.4
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• pp.254-259
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• 2011

Objectives The aim of this study was to assess variations in caudate volume according to dopamin receptor D2/ankyin repeat and kinase domain containing 1 (DRD2/ANKK1) Taq 1a polymorphisms in young healthy adults and to evaluate the relationship between caudate volumes and psychiatric symptoms as measured by the Brief Psychiatric Rating Scale. Methods Genetic information regarding DRD2/ANKK1 Taq 1a and T1-weighted brain magnetic resonance images were acquired from 30 young healthy adults. Automatic segmentation of caudate was performed using the FreeSurfer program. Results Individuals with A2 homozygotes of DRD2/ANKK1 Taq 1a polymorphisms (n = 10) had greater right caudate volumes compared to those with A1 allele (s)(18.4% greater ; p = 0.019). Right caudate volumes were negatively associated with total scores of the Brief Psychiatric Rating Scale (${\beta}$=-0.50 ; p = 0.016). Conclusions Our findings suggest the possibility that DRD2/ANKK1 Taq 1a polymorphisms may underlie the psychiatric symptoms by influencing the structure of the right caudate.

• Korean Journal of Pharmacognosy
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• v.46 no.2
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• pp.105-108
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• 2015

To establish the anti-diabetic(α-glucosidase inhibitory) activity of D. lotus leaf extract, isolate and identify the constituents responsible for the activity. The methanolic extract of leaves was partitioned between water, n-butanol and ethyl acetate. Bio-assay guided fractionation, based on inhibition of ;${\alpha}$-glucosidase, allowed isolation and identification of the active components. Liquid chromatography/mass spectrometry(LC/MS), ¹ H-NMR and ¹³ C-NMR spectra analyses demonstrated that the active compound was myricetin-3-O-;${\alpha}$-L-rhamnoside(1). Compound 1 demonstrated a strong inhibition on the α-glucosidase, in vitro and ;${\alpha}$-glucosidase inhibitory value was calculated as 98.08%, when that of a reference drug, acarbose was estimated as 83.03%. The present study indicates compound 1 could be considered as an ;${\alpha}$-glucosidase inhibitor and developed as an important antidiabetes agent for type II diabetes therapy.

• Journal of Microbiology and Biotechnology
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• v.15 no.4
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• pp.722-727
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• 2005

Cytosolic sialidase (Neu2), a member of the sialidase family that is responsible for hydrolysis of sialic acid from the terminal position of sialoglycoconjugates, is poorly expressed in skeletal muscle and not detected in any other adult tissues. Thus, we isolated Neu2 cDNA using splicing by overlap extension (SOEing). In order to further characterize this enzyme, a His-tagged derivative was expressed in the bacterial expression system and purified by $Ni^{2+}$-affinity chromatography. A recombinant product of approximately 42 kDa had sialidase activity toward 4-methyl-umbelliferyl-$\alpha$-D-N-acetylneuraminic acid (4MU-NeuAc). The optimal pH and temperature of the recombinant Neu2 for 4MU-NeuAc was 6.0 and $37.5^{\circ}C$, respectively. The metal ions, such as $Cu^{2+}\;and\;Cd^{2+}$, showed strong inhibitory effect on the activity of the enzyme. The enzyme efficiently hydrolyzed the gangliosides GM3 and GD3 and had relatively low activities on ganglioside GD1a and GD1b, $\alpha$2-3 sialyllactose, and sialylated glycoproteins such as fetuin, transferrin, and orsomucoid, but had hardly any activities on $\alpha$2-6 sialyllactose and ganglioside GM1 and GM2. We concluded that the recombinant Neu2 has a sialidase activity toward glycoproteins as well as gangliosides.