• BMB Reports
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• v.45 no.10
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• pp.554-559
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• 2012

Oligosaccharide modification by N-acetylglucosaminyltransferase-V (GnT-V), a glycosyltransferase encoded by the Mgat5 gene that catalyzes the formation of ${\beta}1$,6GlcNAc (N-acetylglucosamine) branches on N-glycans, is thought to be associated with cancer growth and metastasis. Overexpression of GnT-V in cancer cells enhances the signaling of growth factors such as epidermal growth factor by increasing galectin-3 binding to polylactosamine structures on receptor N-glycans. In contrast, GnT-V deficient mice are born healthy and lack ${\beta}1$,6GlcNAc branches on N-glycans, but develop immunological disorders due to T-cell dysfunction at 12-20 months of age. We have developed Mgat5 transgenic (Tg) mice (GnT-V Tg mice) using a ${\beta}$-actin promoter and found characteristic phenotypes in skin, liver, and T cells in the mice. Although the GnT-V Tg mice do not develop spontaneous cancers in any organs, there are differences in the response to external stimuli between wild-type and GnT-V Tg mice. These changes are similar to those seen in cancer progression but are unexpected in some aspects. In this review, we summarize what is known about GnT-V functions in skin and liver cells as a means to understand the physiological roles of GnT-V in mice.

• Journal of Microbiology and Biotechnology
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• v.14 no.5
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• pp.891-900
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• 2004

UDP-N-Acetylglucosamine(GlcNAc):$\beta$1,4-D-mannoside$\beta$-l ,4N-acetylglucosaminyltransferase-III (GnT-III) and UDP-N-GlcNAc:$\alpha$-6-D-mannosid$\beta$-1,6N-acetylglucosaminyltransferase-V(GnT - V) activities were determined in human hepatoma cell lines and metastatic colon cancer cells, and their activities were compared with those of normal liver cells and fetal hepatocytes. GnT-III activities were higher than those of GnT-V in hepatic carcinoma cells. When the two enzyme activities were assayed in highly metastatic colon cancer cells, GnT - V activities were much higher than those of GnT-III. When GlcN, GlcN-biant-PA and UDP-GlcNAc were used as substrates, the enzymes displayed different kinetic properties between hepatic and colon cancer cells, depending on their metastatic potentials. Normal cells of two origins had characteristically very low levels of GnT-III and -V activities, whereas hepatoma and colon cancer cells contained high levels of activities. These data were supported by RT-PCR and Northern blot analyses, showing that the expression of GnT-III and -V mRNAs were increased in proportion to the enzymatic activities. The increased GnT-III, md -V activities were also correlated with increased glycosylation of the cellular glycoproteins in hepatoma and colon cancer cells, as examined by lectin blotting analysis by using wheat germ glutinin (WGA), erythroagglutinating phytohemagglutinin (E-PHA), leukoagglutinating phytohemagglutinin (L-PHA), and concanavalin A (Con A). Treatment with retinoic acid, a differentiation agent, resulted in decreases of both GnT-III and -V activities of HepG2 and HepG3 cells. In colon carcinoma cells, however, treatment with retinoic acid resulted in a reduction of GnT-V activity, but not with GnT-III activity. Although the mechanism underlying the induction of these mzymes is unclear, oligosaccharides in many glycoproteins have been observed of cancer cells.

• THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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• v.5 no.1
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• pp.103-118
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• 1999

The activity of N-acetylglucosamitnyltransferase(GnT) III and V on a Melanoma B-16 was examined after incubation with interleukin 1 (IL-1). While augumenting cell proliferation, IL-1 resulted in a decrease of GnT-III activity and an increase of GnT-V activities. Consistant with this, Melanoma B-16 cultured with IL-1 showed increased affinlity to Daturam stramonium lectin, which recognizes asialo-tri- and asialeo-tetra-antenery N-linked oligosaccharides. These results indicate that IL-1 modulate glycosyltransferase activity and the oligosaccharide structure of target cells. On the other hand, to investigate whether or not TKM-SG affect GnT-V gene expression in lung metastatic carcinoma, we used RT-PCR methods. TKM-SG treated cell lines showed low levels of secretion of GnT-V mRNA transcription as elucidated by RT-PCR. Thus, with together lower GnT-V activity levels in the medium, TKM-SG was highly effective for lung cancer metastasis treatment and it was concluded that the medicine can be used as a potent anti-lung cancer metastasis medicine.

• Transactions of the Korean hydrogen and new energy society
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• v.26 no.3
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• pp.206-211
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• 2015

For the hydrogen production, Gas Lab and Gnc make alkaline watrer electrolyzer and found optimized condition of experimental parameters of cell material and operating procedures. For the commercial production, we saved electric power consumption and caloric based efficiency with over 70%. Used cell pressures are 10 bar, 30 bar and consumed electricity is $4,000A/m^2$, 4.19 kW ($T=100^{\circ}C$) at 10 bar. Another data is $2,000A/m^2$, 3.92 kW ($T=95^{\circ}C$) at 30 bar. Applied voltage is 1.75 V ($100^{\circ}C$, 10 bar), 1.64 V ($95^{\circ}C$, 10 bar), 1.81 V ($85^{\circ}C$, 30 bar), 1.76 V ($95^{\circ}C$, 30 bar). As cell temperature increase, applied voltage has been decreased and current has been increased. The concentration of KOH solution is 30 weight %.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2002.02a
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• pp.185-188
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• 2002

In the design of superconducting power equipments such as transformer, cable and fault current limit, knowledge of the dielectric behavior of both liquid and gaseous at very low temperatures is very importance. Especially, Electrical properties of liquid nitrogen($LN_{2}$) and gaseous nitrogen($GN_{2}$) have become of great interest again since the discovery of high temperature superconductors. However, many sources of $LN_{2}$and $GN_{2}$ problems in the test of pancake coil model arising form the deficiency of insulation data. Therefore, this paper describes the results of an experimental study on the ac breakdown voltage($V_{B}$) properties of $LN_2$ and Air under the electrode of simulated HTS pancake coil. The ac breakdown voltage of $GN_{2}$ have been measured by pancake coil-pancake coil gaps over the temperature range of 293 K to 77 K.

• BMB Reports
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• v.44 no.12
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• pp.772-781
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• 2011

Branched N-glycans are produced by a series of glycosyltransferases including N-acetylglucosaminyltransferases and fucosyltransferases and their corresponding genes. Glycans on specific glycoproteins, which are attached via the action of glycosyltransferases, play key roles in cell adhesion and signaling. Examples of this are adhesion molecules or signaling molecules such as integrin and E-cadherin, as well as membrane receptors such as the EGF and TGF-${\beta}$ receptors. These molecules also play pivotal roles in the underlying mechanism of a variety of disease such as cancer metastasis, diabetes, and chronic obstructive pulmonary disease (COPD). Alterations in the structures of branched N-glycans are also hall marks and are useful for cancer biomarkers and therapeutics against cancer. This mini-review describes some of our recent studies on a functional glycomics approach to the study of branched N-glycans produced by N-acetylglucosaminyltransferases III, IV, V and IX (Vb) (GnT-III, GnT-IV, V and IX (Vb)) and fucosyltransferase 8 (Fut8) and their pathophysiological significance, with emphasis on the importance of a systems glycobiology approach as a future perspective for glycobiology.

• Journal of Microbiology and Biotechnology
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• v.18 no.2
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• pp.383-391
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• 2008

The glycans linked to the insect cell-derived glycoproteins are known to differ from those expressed in mammalian cells, partly because of the low level or lack of glycosyltransferase activities. GnT II, GnT IV, GnT V, and ST3Gal IV, which play important roles in the synthesis of tetraantennarytype complex glycan structures in mammalian cells, were overexpressed in Trichoplusia ni cells by using a baculovirus expression vector. The glycosyltransferases, expressed as a fusion form with the IgG-binding domain, were secreted into the culture media and purified using IgG sepharose resin. The enzyme assay, performed using a pyridylaminated-sugar chain as an acceptor, indicated that the purified glycosyltransferases retained their enzyme activities. Human erythropoietin expressed in T. ni cells (rhEPO) was subjected to in vitro glycosylation by using recombinant glycosyltransferases and was converted into complex-type glycan with terminal sialic acid. The presence of Nacetylglucosamine, galactose, and sialic acid on the rhEPO moiety was detected by a lectin blot analysis, and the addition of galactose and sialic acid to rhEPO was confirmed by autoradiography using $UDP-^{14}C-Gal\;and\;CMP-^{14}C-Sia$ as donors. The in vitro glycosylated rhEPO was injected into mice, and the number of reticulocytes among the ed blood cells was counted using FACS. A significant increase in the number of reticulocytes was not observed in the mice injected with in vitro glycosylated rhEPO as compared with those injected with rhEPO.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.24
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• pp.10875-10878
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• 2015

The epidermal growth factor receptor (EGFR) is an important surface receptor with N-glycans in its extracellular domain, whose glycosylation is essential for its function, especially in tumor cells. Here, we demonstrated that polylactosamine is markedly increased in H7721 hepatocellular carcinoma cells after treatment with EGF, while it apparently declined after exposure to all-trans retinoic acid (ATRA). In the study of the enzymatic mechanism of this phenomenon, we explored changes in the expression of poly-N-acetyllactosamine (PLN) branching glycosyltransferases using RT-PCR. Among the four glycosyltransferases with altered expression, GnT-V was most elevated by EGF, while GnT-V and B3GNT2 were most declined by ATRA. Next, we conducted co-immunoprecipitation experiments to test whether B3GNT2 and EGFR associate with each other. We observed that EGFR is a B3GNT2-targeting protein in H7721 cells. Taken together, these findings indicated that the altered expression of B3GNT2 will remodel the PLN stucture of EGFR in H7721 cells, which may modify downstream signal transduction.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.619-622
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• 2005

본 논문에서는 서로 다른 Si 두께 ($T_{Si}$ = 27, 50 nm) 를 갖는 SOI (Silicon On Insulator) 기판 위에 다양한 두께의 Ni/Co를 순차적으로 증착한 후 Bulk-Si과의 비교를 통해 Silicide의 형성 특성에 대하여 분석하였다. 우선 급속 열처리 (RTP, Rapid Thermal Processing) 를 통하여 Silicide를 형성한 후 측정결과 Si두께에 따라 Silicide의 특성이 달라짐을 확인하였다. 두꺼운 두께의 Si-film을 갖는 SOI 기판을 사용한 경우 증착된 금속의 두께에 따라 Bulk-Si와 비슷한 면저항 특성을 보였으나, 얇은 두께의 Si-film을 갖는 SOI기판을 사용한 경우에는 제한된 Si의 공급으로 인한 Silicide의 비저항 증가로 인하여 증착된 금속의 두께에 따라 면저항이 감소하다가 다시 증가하는 'V' 자형 곡선을 나타내었다.