• The Korean Journal of Zoology
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• v.33 no.1
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• pp.108-118
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• 1990

Fibronectin is a glycoprotein found in the extracellular matrix as well as in the serum, and has been known to exert pronouned effed on the myoblast fusion. Our previous studies have suggested that the decrease of fibronectin levels during myogenesis is due to the decreased availability of the receptor for the 28 kDa fragrnent of fibronetin. In the fusion-blocked myoblasts by EGTA, the levels of fibronetin and binding of 28 kDa fragment decreased but far less than the control level. In contrast, the levels of fibronetin and binding of 28 kDa fragment decreased to the control level in the myoblast released from the fusion block. On this account, we suggest that the decrease of fibronetin levels during myoblast fusion is closely associated with the loss or alteration of the receptor for 28 kDa fragment. Mild trypsin treatment decreased the binding of the 28 kDa fragment to the myoblasts significandy. Similarly, the presence of gangliosides in the binding media decreased the binding of the 28 kDa fragment in a dose-dependent manner. Furthermore, gel overlay of 125 I-28 kDa fragment on the SDS-PAGE of the myoblast homogenates revealed that the 28 kDa fragment bound to a 43 kDa protein and to gangliosides as well. These results suggest that myoblast fusion is correlated with decrease of the receptor for the 28 kDa fragment and that the receptor might be a glycoprotein that contains glyco-conjugate found in gangliosides.

• Proceedings of the Korean Biophysical Society Conference
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• 1996.07a
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• pp.16-16
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• 1996

Investigation of the structure of the gangliosides has proven to be very important in the understanding of their biological roles such as regulation of differentiation and growth of cells. Unexchanged hydroxyl protons and amide protons in ganglioside are protrude farther from the carbon backbone than the C-linked protons and provides nOe contacts with other protons which can provide additional distance constraints in structural determination. (omitted)

• BMB Reports
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• v.28 no.6
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• pp.546-551
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• 1995

The conformation studies of myelin P2 protein and two of its major peptides were carried out using circular dichroism and fluorescence spectroscopy in water and in lipid environments. Significant conformational changes occur when the protein or peptides were bound to gangliosides. Similar effects were also found in trifluoroethanol solutions. The conformational features of P2 protein and its major peptides were discussed in relation to the environmental changes and the disease-inducing effects.

• Journal of Microbiology
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• v.33 no.4
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• pp.278-282
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• 1995

S. epidermidis cell was fractionated into cell wall, cell membrane and cytoplasm. The cell membrane adsorbed the most abundant $\textrm{Pb}_{2+}$ per unit dry weight of the three fractions tested. Adsorption behavior of $\textrm{Pb}_{2+}$ in lipid and protein, which are the main components of the cell membrane, indicated that phosphatidylethanolamine and phosphatidylinositol having phosphoryl group and gangliosides containing carboxyl groups adsorbed much more $\textrm{Pb}_{2+}$ than triglycerides lacking any chargeable functional groups. Protein purified from cell membrane adsorbed larger amount of $\textrm{Pb}_{2+}$ than total native cell membrane or cell membrane lipid.

• 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.

• Archives of Pharmacal Research
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• v.23 no.5
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• pp.525-530
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• 2000

mST3GaIV synthesizes ganglioside GM3, the precursor for simple and complex a- and b- series gangliosides, and the expression and regulation of mST3GaIV (CMP-NeuAc: lactosylceramide $\alpha$2,3-sialyltransferase) activity is central to the production of almost all gangliosides, a class of glycosphingolipids implicated in variety of cellular processes such as transmembrane signaling, synaptic transmission, specialized membrane domain formation and cell-cell interactions. To understand the developmental expression of mST3GaIV in mice, we investigated the spatial and temporal expression of mST3GaIV mRNA during the mouse embryogenesis [embryonic (E) days; 19, E11, E13, E15] by in situ hybridization with digoxigenin-labeled RNA probes. All tissues from 19 and E11 were positive for mST3GaIV mRNA. On E13, mST3GaIV mRNA was expressed in various neural and non-neural tissues. In contrast to these, on E15, the telencephalon and liver produced a strong expression of mST3GaIV which was a quite similar to that of E13. In this stage, mST3GaIV mRNA was also expressed in some non-neural tissues. These data indicate that mST3GaIV is differently expressed at developmental stages of embryo, and this may be importantly related with regulation of organogenesis in mice.

• The Korean Journal of Zoology
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• v.39 no.4
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• pp.410-418
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• 1996

Gangilosides are ubiquitous membrane components in mammalian cells and are suggested to play essential roles in cellular phenomena such as cell-cell interadion, differentiation, and signal transduction. Rat ovary contained GM3 as major gangiloside. Nn order to study GM3 distribution in the atretic follicles and its possible changes during follicular development, frozen sections were stained with spedfic monocional antibodies against eleven gangilo-series gangliosides including GM3. In the atretic follicles, Glf3 was expressed in a spatlo-temporally different manner during foilicular development, but GM1 and other gangliosides were not immunohistochemicaily detected. in atretic follicle from primary follicle stage, GM3 was expressed in all the theca cells and some granulosa cells adjacent to oocyte. In atretic follicle from secondary follicle stage, GM3 were expressed in all theca cells and granulosa cells. in atretic follicles from developing Graaflan follicle stages, GM3 was similarly expressed as in secondary follicle stage.

• Journal of Plant Biotechnology
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• v.46 no.3
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• pp.217-227
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• 2019

Production of therapeutic monoclonal antibodies (mAbs) using a plant platform has been considered an alternative to the mammalian cell-based production system. A plant-derived mAb CO17-1AK ($mAb^P$ COK) can specifically bind to various types of cancer cell lines. The target protein of $mAb^P$ COK is the epithelial cell adhesion molecule (EpCAM) highly expressed in human epithelial cancer cells, including breast and colorectal cancer cells. It has been hypothesized that its overexpression supports tumor growth and metastasis. A ganglioside is extended well beyond the surfaces of the various cell membranes and has roles in cell growth, inflammation, differentiation, and carcinogenesis. However, the regulation of EpCAM gene expression in breast cancers and the role of gangliosides in oncogenesis are unclear. Here, the purpose of this study was to determine the effects of $mAb^P$ COK on human breast cancer cell proliferation, apoptosis, and ganglioside expression patterns. Our results show that treatment with $mAb^P$ COK suppressed the growth of breast cancer cells and induced apoptotic cell death. It also upregulated the expression of metastasis-related gangliosides in breast cancer cells. Thus, treatment with $mAb^P$ COK may have chemo-preventive therapeutic effects against human breast cancer.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.175-175
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• 1994

녹용의 유효성분을 분리하기 위하여 지질성분을 분석하고 그 약효를 검색하였다. Folch-Suzuki 분배법, Sephadex G-50, DEAE-Sephadex A-25 Column Chromatography, High Performance Thin Layer Chromatography, HPLC로 정제한후 Mass Spectrometer, NMR, FT-IR등을 이용하여 구조를 분석하였다. 이 물질은 분자량이 1065인 polyhydroxyunsaturated lipid임을 확인하였다. Strepthzotocin으로 당뇨병을 유발시킨 쥐에 이 물질을 투여한 후 혈액과 조직에서 생화학적 변화를 조사하였다. 정상군에 비해 투여군에서 혈당이 감소하였으나 혈액에서 insulin의 양은 증가하지 않았다. 당뇨병 쥐의 적혈구가 정상에 비해 용혈이 되지 않으나 투여군의 적혈구는 정상과 비숫한 용혈현상을 보여 주었다. 대뇌조직에서 gangliosides를 분석한 결과 당뇨병에 의해 GM1이 증가하는 양상을 보여 주었으나 투여군의 경우 대뇌 gangliosides 분포는 정상과 같았다. 대뇌 lipid bound sialic acid를 정량한 결과 당뇨병에 의해 그 양이 감소되었으나 녹용을 투여하였을 때는 정상에 비해 그 양이 더 증가하였다. Strepthzotocin으로 유발시킨 당뇨병 쥐에 녹용의 지질성분을 투여하였을 때 치료효과가 있는 것으로 추정된다.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2005.10a
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• pp.57-58
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• 2005