• Microbiology and Biotechnology Letters
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• v.17 no.5
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• pp.407-411
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• 1989

Extracellular neutral pretense of Streptomyces rimosus producing oxytetracycline was purified by ammonium sulfate fractionation, DEAE Sephadex A-50 chromatography and Sephadex G-100 gel filteration, and was showed single band on the cathodic gel electrophoresis. The optimum pH and temperature of the enzyme were pH 8.0 and 6$0^{\circ}C$, respectively. The enzyme was activated about 80% in the presence of Co$^{2+}$ ion, and strongly inhibited by Hg$^{2+}$, Fe$^{2+}$ and chelatig agent, EDTA. Molecular weight of the enzyme was estimated to be 12, 000. The Km value of the enzyme of casein as a substrate was 2.7$\times$10$^{-4}$M.

• Microbiology and Biotechnology Letters
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• v.36 no.4
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• pp.353-359
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• 2008

Hepatitis C virus (HCV) is known as the causative agent of blood transmitted hepatitis. Two viral proteins, E2 and NS5A, are known to exert interferon resistance of HCV via PKR pathway. Here, we report a third protein, the RNA-dependent RNA polymerase (NS5B) of HCV, induced interferon resistance inhibiting p56 pathway. p56 was shown to interact with p48 subunit of eukaryotic initiation factor 3 (eIF3). This interaction inhibited formation of ternary complex in translation initiation. Using dual reporter assay system, we observed that the translation decreased when interferon alpha was added to the culture. But, in the presence of HCV NS5B, the translation partly recovered. NS5B and p48 subunit of eIF3 were shown to interact. This interaction seems to inhibit the interaction between p48 and p56. This is the first report that a virus exerts interferon resistance via p56 pathway.

• The Korean Journal of Physiology and Pharmacology
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• v.3 no.6
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• pp.579-586
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• 1999

Complement-mediated neutrophil activation has been hypothesized to be an important mechanism of reperfusion injury. It has been proposed that C1 esterase inhibitor (C1 INH) may prevent the complement- dependent activation of polymorphonuclear leukocytes (PMNs) that occurs within postischemic myocardium. Therefore, The effect of C1 INH was examined in neutrophil dependent isolated perfused rat heart model of ischemia (I) (20 min) and reperfusion (R) (45 min). Administration of C1 INH (5 mg/Kg) to I/R hearts in the presence of PMNs $(100{\times}10^6)$ and homologous plasma improved coronary flow and preserved cardiac contractile function (p＜0.001) in comparison to those I/R hearts receiving only vehicle. In addition, C1 INH significantly (p＜0.001) reduced PMN accumulation in the ischemic myocardium as evidenced by an attenuation in myeloperoxidase activity. These findings demonstrate the C1 INH is a potent and effective cardioprotective agent inhibits leukocyte-endothelial interaction and preserves cardiac contractile function and coronary perfusion following myocardial ischemia and reperfusion.

• Journal of Microbiology and Biotechnology
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• v.12 no.2
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• pp.349-353
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• 2002

Two recombinant bacteria containing luxAB showed an increased tolerance to stresses associated with lyophilization, when the cells were freeze-dried in the presence of trehalose. In the case of a recombinant, UV2, only $2.5\%$ of the original bioluminescence and $2.7\%$ of the cell viability were restored after 4 h of freeze-drying without trehalose, which implies that the cells were heavily damaged during the dehydration. To improve these losses, trehalose was added before freeze-drying using different modes. Trehalose increased the bioluminescence and the viability of freeze-dried UV2 under all conditions tested, and it was also observed that the addition of trehalose to the cultures (final concentration of 0.08 M) for 15 min before the freeze-drying resulted in the restoration of $45\%$ of the original bioluminescence and $50\%$ of the cell viability. Trehalose also showed a similar efficacy with the other luminescent recombinant, YH9. Therefore, it was tentatively concluded that trehalose played a role as a protective agent in the freeze-drying of bacterial cells.

• Journal of Microbiology and Biotechnology
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• v.17 no.10
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• pp.1727-1732
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• 2007

Phenylacetic acid (PAA) is produced by many bacteria as an antifungal agent and also appears to be an environmentally toxic chemical. The object of this study was to detect PAA using Pseudomonas putida harboring a reporter plasmid that has a PAA-inducible promoter fused to a green fluorescent protein (GFP) gene. Pseudomonas putida KT2440 was used to construct a green fluorescent protein-based reporter fusion using the paaA promoter region to detect the presence of PAA. The reporter strain exhibited a high level of gfp expression in minimal medium containing PAA; however, the level of GFP expression diminished when glucose was added to the medium, whereas other carbon sources, such as succinate and pyruvate, showed no catabolic repression. Interestingly, overexpression of a paaF gene encoding PAA-CoA ligase minimized catabolic repression. The reporter strain could also successfully detect PAA produced by other PAA-producing bacteria. This GFP-based bioreporter provides a useful tool for detecting bacteria producing PAA.

• Journal of Pharmaceutical Investigation
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• v.35 no.6
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• pp.445-451
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• 2005

As a selective ${\alpha}_{1A}-adrenoreceptor$ antagonist, tamsulosin has been used clinically for urinary obstructed patients with benign prostatic hyperplasia. The single and multi-layered pellets containing tamsulosin hydrochloride were prepared in an effort to control the drug release, avoiding dose-dependent side effects of tamsulosin hydrochloride upon oral administration. The drug release from multi-layered pellets was substantially controlled, compared with single layered pellets. The drug release from coated pellets with single or multi layer was affected by the nature of coating agent, the percentage of coating level and the presence of hydrophilic material in coating layer. In conclusion, the controlled release oral delivery system using multi-layered pellet is very useful for tamsulosin hydrochloride, resulting in improvement of patient compliance and therapeutic drug levels for a longer period of time.

• Journal of Conservation Science
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• v.35 no.4
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• pp.269-277
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• 2019

Seaweed extracts, namely carrageenan obtained from Grateloupia elliptica and algin obtained from Laminaria, were employed as adhesive agents to synthesize solid adhesives for paper. Carrageenan from Grateloupia elliptica with the highest adhesive strength and lgin from Laminaria with the highest compressive strength was selected. The selected carrageenan and algin were mixed in a ratio of 7:3, and the mixture was employed as an adhesive agent. At a high temperature, sodium stearate(used as a solidifying material) oxidized the seaweed extracts. Consequently, carrageenan and algin were added to the final manufacturing process. The adhesive strength of the final synthesized solid adhesive is found to be 3.02 MPa and the compressive strength is found to be 30.5 N. Compared to the adhesive strength (2.95 MPa) and compressive strength (30.11 N) of commercial solid adhesives, the obtained results indicate superior adhesion characteristics. Furthermore, the proposed adhesive is environment-friendly because the presence of volatile organic compounds, formaldehyde, and heavy metals(such as chromium, lead, and cadmium) were not detected. Moreover, when used, the flatness of paper was twice that of commercial solid paper adhesives. Hence, the proposed adhesive can provide excellent adhesion, stability, and usability.

• Journal of the Korean Applied Science and Technology
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• v.24 no.2
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• pp.167-173
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• 2007

The surface of poly(ethylene naphthalate) film applicable to high temerature insulator for convection microwave oven was modified with silicone coating solutions in the presence of silane crosslinking agent. The structure and properties of the PEN films were investigated by using Fourier transform IR spectroscopy, viscometry, microscopy, and tensile tests. The experimental results showed that the coating with silicone enhanced thermal stability up to $200^{\circ}C$, and slightly lowered the tensile strength and elongation of the PEN films. Judging from dimensional stability results the silicone coated PEN films can not be used for higher temperature insulator above $230^{\circ}C$. Serious dimensional contraction of films was obtained during heat treatment at $250^{\circ}C$ even for 1h. However, the surface of those films still have same chemical structure of silicones. Therefore, If we use PEN film prestretched at $230^{\circ}C$ as base one it will be possible to prepare a high temperature insulator up to $230^{\circ}C$. Conclusively, a silicone coated PEN film can be suitable for the application to convection microwave oven door insulator at high temperature up to $230^{\circ}C$.

• Journal of Microbiology and Biotechnology
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• v.13 no.5
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• pp.666-672
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• 2003

Vacuolar degeneration of the gastric epithelial cells is a characteristic feature of the derangement of mucosa where Helicobacter pylori colonizes, and H. pylori vacuolating cytotoxin (VacA) has been suggested to playa key role in it. To elucidate the VacA-involved degenerative mechanism, VacA was purified, and its impact on degeneration of HeLa cells was determined. In the presence of ammonium chloride, cell vacuolation by VacA was dose-and time-dependent, however, no detectable degeneration of the cells was observed with the VacA concentration tested. A further increase of vacuolation was shown in cells pre-treated with diethyl pyrocarbonate (DEPC) , and this resulted in a change of the cell morphology to become spherical. Similar phenomena were also observed when HeLa cells were co-cultivated with intact H. pylori cells. It was remarkable to note that the degree of growth inhibition was proportional to the increase in vacuole formation, suggesting that the vacuolation rate would be critical for cell degeneration. Surprisingly, although VacA was itself inhibited by DEPC, its uptake was markedly increased by this agent, similar to that found in cells with Nabutyrate. These data indicate that the cell's tolerance of VacA transport may be critical for vacuolar degeneration and may be changeable during H. pylori inhabitation.

• Journal of Microbiology and Biotechnology
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• v.3 no.3
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• pp.168-173
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• 1993

The expression kinetics of human lipocortin I (LCI), a potential anti-inflammatory agent, was studied in the shake-flask and fermenter cultures of Saccharomyces cerevisiae carrying a galactose-inducible expression system. The cell growth, expression level of LCI, and the plasmid stability were investigted under various galactose induction conditions. The expression of LCI was repressed by the presence of a very small amount of dextrose in the culture medium, but it was induced by galactose after dextrose became completely depleted. The optimal ratio of dextrose to galactose for lipocortin I production was found to be 1.0 (10 g/l dextrose and 10 g/l galactose). With optimal D/G ratio of 1.0 and the addition of galactose prior to dextrose depletion, LCI of about 100~130 mg/l was produced. LCI at a concentration of 174 mg/l was porduced in the fed-batch culture, which was nearly a twice as much of that produced in the batch culture. The plasmid stability was very high in all culture cases, and thus was considered to be not an important parameter in the expression of LCI.