• Journal of Microbiology and Biotechnology
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• v.30 no.2
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• pp.259-270
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• 2020

Listeria monocytogenes is a gram-positive, facultative anaerobe food pathogen responsible for the listeriosis that mostly occurs during the low-temperature storage of a cold cut or dairy products. To understand the systemic response to a wide range of growth temperatures, L. monocytogenes were cultivated at a different temperature from 10℃ to 42℃, then whole cell proteomic analysis has been performed both exponential and stationary cells. The specific growth rate increased proportionally with the increase in growth temperature. The maximum growth rate was observed at 37℃ and was maintained at 42℃. Global protein expression profiles mainly depended on the growth temperatures showing similar clusters between exponential and stationary phases. Expressed proteins were categorized by their belonging metabolic systems and then, evaluated the change of expression level in regard to the growth temperature and stages. DnaK, GroEL, GroES, GrpE, and CspB, which were the heat&cold shock response proteins, increased their expression with increasing the growth temperatures. In particular, GroES and CspB were expressed more than 100-fold than at low temperatures during the exponential phase. Meanwhile, CspL, another cold shock protein, overexpressed at a low temperature then exponentially decreased its expression to 65-folds. Chemotaxis protein CheV and flagella proteins were highly expressed at low temperatures and stationary phases. Housekeeping proteins maintained their expression levels constant regardless of growth temperature or growth phases. Most of the growth related proteins, which include central carbon catabolic enzymes, were highly expressed at 30℃ then decreased sharply at high growth temperatures.

• Journal of the Korean Magnetic Resonance Society
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• v.17 no.1
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• pp.30-39
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• 2013

Immortalization-upregulated protein-1 (IMUP-1) genes have been cloned and are known to be involved in SV40-mediated immortalization. IMUP-1 gene is highly expressed in various cancer cell lines and tumors, suggesting the possibility that they might be involved in tumorigenicity. Previously, there were several problems for overexpression of IMUP-1 in bacterial expression systems including low solubility and aggregation due to unstructured property. To investigate the structural properties, it is necessary to obtain lots of pure and soluble proteins. Accordingly, the co-expression systems of bacterial chaperone proteins, GroEL-GroES, were used to increase solubility of IMUP-1. From the analysis of NMR and CD experiment data, it is suggested that the protein adopt typical the random coil properties in solution.

• Journal of Microbiology and Biotechnology
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• v.28 no.5
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• pp.739-747
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• 2018

The low solubility and high-cost recovery of Propionibacterium acnes polyunsaturated fatty acid isomerase (PAI) are key problems in the bioproduction of high value-added conjugated linoleic acid (CLA). To improve the solubility of recombinant PAI, six chaperone proteins were coexpressed with PAI. Introduction of GroELS proteins dramatically improved the PAI solubility from 29% to 97%, with increased activity by 57.8%. Combined expression of DnaKJ-GrpE and GroELS proteins increased the activity by 11.9%. In contrast, coexpression of DnaKJ-GrpE proteins significantly reduced the activity by 57.4%. Plasmids pTf16 harboring the tig gene and pG-Tf2 containing the tig and groEL-groES genes had no visible impact on PAI expression. The lytic protein E was then introduced into the recombinant Escherichia coli to develop a cell autolysis system. A 35% activity of total intracellular PAI was released from the cytoplasm by suspending the lysed cells in distilled water. The PAI recovery was further improved to 81% by optimizing the release conditions. The lipase from Rhizopus oryzae was also expressed in E. coli, with an extracellular activity of 110.9 U/ml. By using the free PAI and lipase as catalysts, a joint system was established for producing CLA from sunflower oil. Under the optimized conditions, the maximum titer of t-10,c-12-CLA reached 9.4 g/l. This work provides an effective and low-cost strategy to improve the solubility and recovery of the recombinant intracellular PAI for further large-scale production of CLA.

• Microbiology and Biotechnology Letters
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• v.43 no.3
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• pp.212-218
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• 2015

Fucosyltransferases (FucTs) catalyze fucosyl transfer from guanosine-diphosphate fucose (GDP-β-L-fucose) to acceptor molecules to form fucosyloligosaccharides with α-glycosidic linkages. However, when FucT genes have been expressed in Escherichia coli, most cases have resulted in the production of inclusion bodies. In this study, to overcome this drawback, molecular chaperones were co-expressed with α1,2-fucosyltransferase (FucT2) in E. coli. For this, the pACYC184 vector, having genes for chaperones such as GroEL, GroES, DnaK, DnaJ, and GrpE, were transformed into E. coli BL21 (DE3) star harboring pHFucT2, including the FucT2 gene from Helicobacter pylori 26695. The results from SDS-PAGE showed that 5 chaperones were successfully expressed and the soluble fraction of FucT2 was also increased. HPLC analysis revealed that the coexpression of chaperone proteins resulted in a 5-fold increase in the total activity of fucosyltransferase in E. coli. In conclusion, the FucT2 expression system developed in this study can be used as a useful tool for the synthesis of fucosyloligosaccharides.

• Korean Journal of Environmental Biology
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• v.20 no.3
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• pp.237-244
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• 2002

To analyze proteins related to antifungal activity, SAR01 strain was isolated from seaweed and identified as Streptomyces sp. from the result of FAME (fatty acid methyl ester) analysis. The isolated strain had antifungal activities against T species of plant pathogenic fungi. Antifungal activity deficient mutant (SAR 535) of Streptomyces sp. SAR01 was induced by gamma radiation $(^{60}Co,\;5kGy)$. By 2 D electrophoresis analysis, 6 protein spots were found in wild strain (SAR01) but these spots disappeared in mutant strain (SAR535). Among them, 5 proteins showed similarities to heat shock protein 70(HSP70), Fe-containing superoxide dismutase II (Fe- SODII), ribosome recycling factor (RRF), 10 kDa chnperonin (GroES) and inorganic pyrophosphatase (PPAse), respectively. It suggested that the above 6 proteins could be closely related to the antifungal activity of Streptomyces sp. SAR01.

• Koreanishche Zeitschrift fur Deutsche Sprachwissenschaft
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• v.8
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• pp.247-272
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• 2003

Mit der Entwicklung der Informations- und Kommunikationstechnologien $er\"{o}ffnen$ $Internet-unterst\"{u}tzte$ Lehren und Lernen neue $M\"{o}glichkeiten{\;}f\"{u}r$ den Sprach- und Kulturunterricht. Das Internet bietet den $Sch\"{u}lern$ vor allem $gro{\ss}es$ Interesse und $gro{\ss}e$ Motivation $f\"{u}r$ die deutsche Sprache und Kultur. In der vorliegenden Arbeit geht es vor allem um die praktische Anwendung von den $M\"{a}rchentexten$ in der germanistischen Abteilung der koreanischen $Universit\"{a}ten$. $M\"{a}rchen$ sind ein Kulturgut, das sich in vielen $V\"{o}ilkern$, Kulturen und Gegenden der Erde findet. $M\"{a}rchen$ sprechen eine Sprache der Symbole und Bilder, eine Sprache, die den Menschen in seiner $Emotionalit\"{a}t$ besonders anspricht. Sie haben eine Anziehungskraft, die uns nicht $unber\"{u}hrt{\;}l\"{a}sst$. Sie zeigen in vie1en Kulturen Motive menschlichen Daseins, die $\"{u}bereinstimmende$ Merkmale zeigen. In dieser Studie wird insbesondere $\"{u}ber$ eine untenichtspraktische Anwendung des $M\"{a}rchens$ $f\"{u}r$ den Deutschunterricht diskutiert. In dieser Arbeit bezieht sich der wissenschaftliche Gebrauch des Kulturbegriffes meist auf kollektive Erscheinungen, die Gruppen von Individuen einigen. Mit Hilfe des Internets kann man verschiedene Kulturelemente in der bestimmten deutschen Stadt finden. Zum Beispiel hat die freie Hansestadt Bremen die wohlgeformte Homepage. In dieser Homepage(http://www.bremen.de/) gibt es viele Informationen $\"{u}ber$ die Stadt Bremen; Geschichte, Wrrtschaft, Wissenschaft, Schulsystem, Kultur, Sport, Freizeit usw. Schuler lernen erst elementare $W\"{o}rter$, Grammatik und dann wichtige kulturelle Elemente. $Erw\"{u}nscht$ waren wissenschaftlich fundierte Methoden $f\"{u}r$ den deutschen Kulturuntenicht und systematisch aufgebaute Internetseiten, die fur bestimmte Deutschkurse an den koreanischen $Universit\"{a}ten$ gedacht sind. Es ware ideal, audiovisuelle/multimediale Webseiten/Webpages mit Texten, Bildern, Webaufgaben und Audio-Nideofiles zu erstellen.

• Journal of Microbiology and Biotechnology
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• v.18 no.2
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• pp.228-233
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• 2008

Effects of chaperones on mRNA stability and gene expression were studied in order to develop an efficient Escherichia coli expression system that can maximize gene expression. The stability of mRNA was modulated by introducing various secondary structures at the 5'-end of mRNA. Four vector systems providing different 5'-end structures were constructed, and genes encoding GFPuv and endoxylanase were cloned into the four vector systems. Primer extension assay revealed different mRNA half-lives depending on the 5'-end secondary structures of mRNA. In addition to the stem-loop structure at the 5'-end of mRNA, coexpression of dnaK-dnaJ-grpE or groEL-groES, representative heat-shock genes in E. coli, increased the mRNA stability and the level of gene expression further, even though the degree of stabilization was varied. Our work suggests that some of the heat-shock proteins can function as mRNA stabilizers as well s protein chaperones.

• Koreanishche Zeitschrift fur Deutsche Sprachwissenschaft
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• v.8
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• pp.25-60
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• 2003

Die Pluralformen (-(e), -( e)n, -'e, -'er, -s) sind durch die Flexionsklassen detenniniert. Basierend auf Genus und prosodischen Eigenschaften werden Plural­klassen unterschieden. Unter den Substantiven mit konsonantischem Wortauslaut wahlen die Feminina den (e)n-Plural, die Maskulina und Neutra im Allgemeinen aber den (e)-Plural. Es ist also anzunehmen, dass es fur jede Flexionsklasse eine vorhersagbare regulare Pluralbildung gibt Die Bildungen mit Umlaut (-'(e)-PI. und -'er-Pl) unterscheiden sich durch die deutlicheren, $verst\"{a}rkten$ Pl.-Markierungen vom einfachen Typ. Im Hinblick auf die $Regularit\"{a]ten$ im Pluralsystem ist festzustellen, dass die Numerusmarkierung bei den Feminina konsequenter ist als bei den Maskulina und Neutra. Im Weiteren spielt bei der Beschreibung der Pluralbildung der Begriff Markiertheit eine $gro{\ss}e$ Rolle. $Anschlie{\ss}end$ wird gezeigt, dass das Pluralsystem nach $Beschr\"{a}nkungen$ aufgebaut ist, die silbenphonologischer und morphologischer Natur sind. Im Rahmen der $Optim\"{a}litatstheorie$ werden die Pluralanalysen von Wegener und Wunderlich vorgestellt. Dabei werden die verschiedenartigen Pluralbildungen mithilfe zusammengestellter Begriffsinstrumentarien, die $f\"{u}r$ die Auswahl einer guten Pluralform ausreichen, vereinfacht dargestellt. Damit bestatigt sich das Plural system im Deutschen als nach klaren Prinzipien geordnet, wenn es auch komplex ist. $Schlie{\ss}lich$ wird der s-Plural als markierte Pluralform $ausf\"{u}hrlich$ gezeigt. Die These, der s-Plural sei der Defaultwert und einzige $regul\"{a}re$ Plural im Deutschen, gilt nur mit $Einschr\"{a}nkung$, da dieser Typ $haupts\"{a}chlich$ in bestimmten Bereichen des Wortschatzes auftritt. Es $w\"{a}re$ also angebracht, den s-Plural als 'unmarkierte Pluralform im markierten Bereich' anzusehen.

• Journal of the Korean Magnetic Resonance Society
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• v.18 no.2
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• pp.47-51
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• 2014

Larger proteins (above molecular weight 50 kDa) usually show slow motional tumbling in solution, which facilitates the decay of NMR signal, resulting in poor signal-to-noise. In the past twenty years, researchers have tried to overcome this problem with higher molecular weight by improvement of hardware (higher magnetic field and cryoprobe), optimization of pulse sequences for lager molecules, and development of isotope-labeling techniques. Actually, GroEL/ES complex (${\approx}$ 900 kDa) was successfully studied using combination of above techniques. Among the techniques used in large molecular studies, the impact of isotope-labeling for large molecules study is summarized and discussed here.

• Journal of Microbiology and Biotechnology
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• v.18 no.2
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• pp.299-307
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• 2008

Soybean seed ferritin is essential for human iron supplementation and iron deficiency anemia prevention because it contains abundant bioavailable iron and is frequently consumed in the human diet. However, it is poorly understood in regards its several properties, such as iron mineralization, subunit assembly, and protein folding. To address these issues, we decided to prepare the soybean seed ferritin complex via a recombinant DNA approach. In this paper, we report a rapid and simple Escherichia coli expression system to produce the soybean seed ferritin complex. In this system, two subunits of soybean seed ferritin, H-2 and H-1, were encoded in a single plasmid, and optimal expression was achieved by additionally coexpressing a team of molecular chaperones, trigger factor and GroEL-GroES. The His-tagged ferritin complex was purified by $Ni^{2+}$ affinity chromatography, and an intact ferritin complex was obtained following His-tagged enterokinase (His-EK) digestion. The purified ferritin complex synthesized in E. coli demonstrated some reported features of its native counterpart from soybean seed, including an apparent molecular weight, multimeric assembly, and iron uptake activity. We believe that the strategy described in this paper may be of general utility in producing other recombinant plant ferritins built up from two types of subunits.