• Applied Microscopy
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• v.24 no.1
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• pp.102-113
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• 1994

A thin section of the methanogenic archaebacterium, Methanoplanus limicola, shows that the surface glycoprotein array (S-layer) is separated from plasma membrane by a distinct inter-space, approximately 4.0-6.0nm wide. We report our structural study of the S-layer by electron crystallographic techniques. Image analysis and thin sections of the S-layer treated with and without triton disclosed that retention of the single layer crystal requires the presence of detergent to avoid hydrophobic bonding.

• Journal of Dairy Science and Biotechnology
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• v.15 no.1
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• pp.27-32
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• 1997

Most lipids in milk are dispetsed as the form of fat globules. Apical portion of plasma membrane is coated with fat globules, which are synthesized from mammary epithelial cells and then secreted into the lumen. The unique phenomenon in separation of the plasma membrane from the cell is observed only in mammary system. It has been suggested that milk fat globule membrane(MFGM) is formed from endoplasmic reticulum, Golgi apparatus, secretory granule to plasma membrane. For this reason MFGM is important for nuderstanding the structure and function of biological membrane. Because MFGM also plays an important role in inhibition of lipase action, stimulation of nutrient digestion and absorption, emulsion or function as natural liposome, study of the major components in MFGM will provide the opportunity for more broad industrial uses of MFGM in the future.

• Journal of the Korean Applied Science and Technology
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• v.26 no.3
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• pp.248-262
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• 2009

This study is on the feasibility of use of glycoprotein in various areas such as cosmetics and food etc. by extracting, isolating and refining glycoprotein from carrots, red ginseng extract residue, sesame and pine needles using protease(pepsin) and by analyzing general characteristics and measuring various bioactivities. The results of analysis of nutritional composition showed protein contents of glycoprotein. In the analysis of constitutive amino acids, the ratio of contents of hydroxy proline and glycine, the characteristics of glycoproteins appeared similar and the contents of glutamic acid and aspartic acid appeared higher. As a result of measurement contents of total polyphenol and flavonoid, it showed that glycoprotein had more contents generally, and the effect of bioactivity of glycoprotein appeared higher although different kinds of glycoprotein showed a little DPPH radical and nitrite scavenging ability, total antioxidant capacity by ABTS, ACE inhibitory.

• The Zoological Society Korea : Newsletter
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• v.18 no.2
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• pp.33-37
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• 2001

Intercellular adhesion molecule-1 (ICAM-1)은 T 세포의 활성이나 면역세포가 염증작용이 일어나고 있는 곳으로 옮겨갈 때 중요한 역할을 수행하는 당단백질 (glycoprotein)으로서 2-integrin 계열의 분자인 leukocyte function associated antigen-1(LFA-1)이나 Mac-1의 수용체이며 세포의 막에 homodimer인 상태로 발현되어진다. ICAM-1은 5개의 세포외 domain과 transmembrane domain(TM) 및 짧은 cytoplasmic domain을 갖고 있으며, dimerization motif는 domain 5 또는 TM인 것으로 알려져 있다. 최근의 crystal 구조분석 결과에 의하면 domain 1에도 dimerization motif가 있는 것으로 추정되어지지만 정확한 실험적인 뒷받침이 되어져 있지 않다. 본 연구에서는domain 1에 dimer를 형성할 수 있는 motif가 존재하는 지에 대한 실험적인 증명과 함께 ICAM-1이 세포의 막에서 어떠한 구조를 갖고 있는지에 대한 최근의 연구성과를 보고하고자 한다.

• The Korean Journal of Zoology
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• v.35 no.2
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• pp.183-193
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• 1992

흰쥐 정자의 성숙과정중에 일어나는 부정소 상피세포, 내강 및 정자 사이의 상호관계를 알아보기 위하여 각 실험군 별로 웅성호르몬 투여에 따른 탄수화물 관기의 함량 변화를 측정하였고, tunicamycin 투여 후 hexosamine의 할량 변화를 살펴봄으로써 glycosylation되는 장소를 확인하였다. 부정소두와 부정소이 상피세포내의 hexose 함량은 거세 후 5일군부터 유의성있게 감소하였고, testosterone 투여시는 각각 5일 , 10일군부터 유의하게 증가하였으며 , hexosamine과 sialic acid의 경우도 통계적으로 유의하게 변화하는 시기는 달랐으나 hexose와 유사하게 증가와 감소하는 경향이 나타났으므로 이러한 하나하나의 탄수화물 관기의 함량 변화는 웅성호르몬에 의존적임을 알 수 있었다. Tunicamycin을 투여하여 hexosamine의 함량 변화를 측정하였을 때 투여 기간에 따라 상피세포와 내강액에서 유의하게 감소하였으나, 정자에서는 일관성있게 감소되지 않았으므로 정자가 직접 hexosamine또는 여러 당단백질 합성에 관여하는 것은 아니며 부정소상피세포나 내장에 의하여 영향받을 수 있다는 가능성을 확인하였다.

• Development and Reproduction
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• v.4 no.1
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• pp.87-93
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• 2000

Equine chorionic gonadotropin (eCG) consists of highly glycosylated noncovalently linked $\alpha$- and $\beta$-subunits and belongs to the glycoprotein hormone family that includes lutropin (LH), follitropin (FSH), and thyrotropin (FSH). eCG is a unique member of the gonadotropin family because it elicits response characteristics of both FSH and LH in other species than the hone. eCG is synthesized and secreted by trophoblastic cells of the endometial cups between 40 and 130 days of gestation. In the present study, mRNA expression ratio of eCG, eLH and eFSH $\alpha$- and $\beta$-subunints was investigated in the placenta and pituitary. mRNA was extracted from equine placenta on day 70 of gestation and from pituitary of male horse (27 month-old). When the expression of both subunit mRNAs of eCG in the equine placenta was compared by Northern blotting, the expression of the $\beta$ -subunit mRNA was relatively greater than that of the $\alpha$-subunit. And mRNA expression of $\alpha$-, LH $\beta$- and FSH $\beta$-subunits was analysed in the equine pituitary. An $\alpha$-subunit was revealed with a size of approximately 0.8 kb. FSH $\beta$-subunit mRNA also was detected out 1.8 kb. It is the same size of the FSH $\beta$ -subunit mRNA cloned. The intensity of $\alpha$-subunit mRNA was greater than that of the $\beta$-subunit suggesting that the expression of $\alpha$ -subunit was dominant in the equine anterior pituitary. Thus, the subunit mRNA levels seem to be independently regulated and their imbalance may account for differences in the quantities of $\alpha$- and $\beta$-subunits in the equine placenta and pituitary.

• Microbiology and Biotechnology Letters
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• v.32 no.2
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• pp.142-148
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• 2004

Erythropoietin is a main regulator of human erythropoiesis. Recombinant human erythropoietin (rhEPO) is one of the glycoproteins produced in animal cells, and it has oligo saccharides chains which comprise about 40％ of its molecular mass. Because the content of sialic acid can extend circulatory lifetime, the high degree of sialylation is often a desirable feature of therapeutic glycoproteins. In this study, the sialylation of rhEPO produced by chinese hamster ovary cell culture was maximized by supplementing the culture medium with N-acetylm-annosamine (ManNAc), a direct intracellular precursor for sialic acid synthesis and 2-deoxy-2,3-dehydro-N-acetylneuraminic acid (NeuAc2en), a sialidase inhibitor. Feeding of 20 mM ManNAc/0.5 mM NeuAc2en into culture medium increased the sialic acid content by nearly tenfold compared with unsupplemented medium. This effect was achieved without affecting the cell growth or product yield. Six erythropoietin fractions differing in sialic acid content, ranging from 11∼15％ of EPO, were identified from chinese hamster ovary cell-derived rhEPO by mono Q column chromatography. It was found that, at 20 mM ManNAc/0.5 mM NeuAc2en feeding, productivity of hyper-glycosylated EPO increased up to 50％, compared with the unsupplemented medium.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.236-243
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• 2023

Platelets act a fundamental role in primary- and secondary-hemostasis, however, platelet activation may cause thrombosis simultaneously. Therefore, control of platelet aggregation is crucial in preventing thrombosis-mediated diseases. Recently, the development of insect materials is attracting attention. Among the highly nutritious functional food sources, insects such as two-spotted cricket (Gryllus bimaculatus). Gryllus bimaculatus (G. bimaculatus) contains high protein and unsaturated fatty acids and has been registered as a food material September 2015 by the Ministry of Food and Drug Safety of Korea. In this study, we examined whether G. bimaculatus extract (GBE) inhibits platelet aggregation, intracellular calcium mobilization, thromboxane A₂ production and glycoprotein IIb/IIIa (integrin αIIb/β3) activation. We investigated whether GBE can regulate signaling molecules, such as 1, 4, 5-triphosphate receptor type I, extracellular signal-regulated kinase, cytosolic phospholipase A₂, mitogen-activated protein kinases p38, vasodilator-stimulated phosphoprotein, phosphatidylinositol-3 kinase, Akt, glycogen synthase kinase-3α/β, and SYK. Taken together, GBE is a potential therapeutic drug candidate to prevent platelet-related thrombosis and cardiovascular disease.

• KSBB Journal
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• v.16 no.6
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• pp.547-553
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• 2001

Glycoprotein from the water extract of dried root barks of slippery Elm was investigated for its anticancer immunostimulating activity, The glycoprotein contained molecular weight 15,000 to 500,000 Da, total carbohydrates 55.8 to 72.1%), total uronic acid 30.0 to 30.5%, and total proteins 5.0 to 6.1%. The anticancer immunostimulating activities were examined for both in vitro bioassays such as immune cell proliferation assay, mixed lymphocyte reaction (MLR), direct mitogenicity, T-dependent antibody production, and in vivo bioassays such as septic shock test and anticancer activity test in B16 melanoma transplanted mouse model. In vivo assay, the glycoprotein at the concentration of 3 mg/kg showed the best result that median survival time increased to about 140% in contrast to control groups.

• KSBB Journal
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• v.16 no.6
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• pp.554-561
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• 2001

Immunostimulating exopolysaccharides with anticancer activity produced by Enterobacter sp. SSYL(KCTC 0687BP), isolated from Chinese elm(Ulmus sp.) were investigated. The exopolysaccharide contains molecular weight 100,000 to 1,000,000 Da and total carbohydrates 43.0 to 70.8%, total uronic acid 7.1 7o 12.4%, and total proteins 15.4 to 20.6%. Compositions and contents of sugars in the exopolysaccharides are 10-30% glucose, less than 1% fructose, 10-15% galactose, 8-12% fucose, and 40-70% glucuronic acid. The anticancer immunostimulating activities were examined and proved with regard to both in vitro and in vivo bioassays. In vivo assay, the glycoprotein at the concentration of 0.3 mg/kg showed the best result that median survival time in creased to ca. 138.1% in contrast to control groups.