• 약학회지
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• 제50권3호
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• pp.166-171
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• 2006

A calcium-dependent sialic acid-binding lectin has been isolated by thyroglobulin-affinity chromatography from the coastal crab Macrophthalmus Japonicus. This lectin, Macrophthalmus Japonicus lectin (MJL), was eluted with 50mM Tris-HCl, 0.3 M NaCl, 10 mM EDTA, and the recovery yield from the crude protein extract was about 5.6%. The molecular weight of MJL was estimated as 65 kDa in SDS-PAGE both under reducing and non-reducing conditions. MJL induced an agglutination reaction in rabbit, rat, and mouse erythrocytes, but not in human ABO types. This activity was effectively inhibited by sialoglycoproteins such as fetuin, bovine submaxillary mucin, and thyroglobulin.

• BMB Reports
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• 제29권3호
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• pp.248-252
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• 1996

The epidermal organ of the leech contains a complex glycoprotein molecule of mucus. The mucus excreted from annelids plays Significant role in protection against desiccation and parasites. Mucus from the Korean native leech, H. nipponia, was investigated for biochemical characteristics for possible development of biomaterials of cosmetic and pharmaceutical agents. The leech skin mucus was heavily glycosylated mucin-like protein with a high molecular weight comprised 80% carbohydrate and 20% protein. Threonine, serine, and glycine were the major components of the isolated protein and these accounted for 50% of total amino acids. The carbohydrate portion contained glucosamine, galactosamine. galactose, glucose. mannose and sialic acid in oligosaccharide form linked with threonine and serine residues of the glycoprotein.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
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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.

• BMB Reports
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• 제30권6호
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• pp.385-389
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• 1997

Many cell types are known to stimulate $CD8^+$ T cells in allogeneic recognition such as mixed lymphocyte reaction (MLR). Whereas dendritic cells are most potent among them. T cells are usually considered very poor in stimulating $CD8^+$ T cells although there are some tumor cells that are weakly stimulatory. T cells, as a stimulator, cultured in the presence of concanavalin A that were otherwise nonstimulatory to $CD8^+$ T cells appeared to stimulate $CD8^+$ T cells strongly when they were pretreated with neuraminidase. The enhancement of MLR by neuraminidase could be achieved by treating either the stimulators or responders with neuraminidase. Removal of negatively-charged sialic acid moieties from the cell surface, which reduced electrostatic repulsion between responders and stimulators to give better cell-cell contact might be responsible for the enhanced MLR. In addition, neuraminidase treatment also appeared to deliver activation signal to responding T cells since it could activate $CD8^+$ T cells in synergy with phorbol myristate acetate. The maximal responses were observed when both responders and stimulators were treated with neuraminidase.

• Natural Product Sciences
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• 제6권1호
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• pp.5-10
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• 2000

The chloroform extract of the seeds of Carica papaya has been screened for the hormonal properties using ovariectomized female rats for estrogenicity, estrogen primed immature rats for progestogenicity and castrated adult male rats for androgenicity. The results revealed that the extract lacks progestogenicity and androgenicity as evident from the failure of the extract treated animals to mimic progestogen and androgen related changes in the target tissues. The increased weight of vagina and uterus, open status of vagina, cornified and epithelial cells in the vaginal smears and hypertrophy in the uterine epithelium, endometrium and stroma with increased glycogen and sialic acid content in the uterus of the chloroform extract treated animals, which are comparable to those of the ovariectomized estrogen treated animals, suggest that the chloroform extract possesses mild estrogenic activity.

• Archives of Pharmacal Research
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• 제17권5호
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• pp.309-313
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• 1994

Phytase of rat intestine had a large amount of oilgosacchanrides ; The enzyme consisted of two different subunits with the molecular weights of 90 KDa and 70 KDa in its intack form, whereas the apparent molecular weights tumed to 72 KDa and 52 KDa, respectively, after deglycosylation. The treatment with glycopeptidase F reduced the molecular weights from 90 KDa and 70 KDa to 83 KDa and 52 KDa, respectively, While endoglycosidase H caused no change in their molecular weights. These results indicate that the 70KDa subunit contains only the N-linked oilgosaccharide chains, while the 90KDa subunit ocntains O-linked oilgosaccharides as well as N-linked ones. Enzyme-linked lectin assays suggeted that bisecting N-acetyl-D-glucosamine and galactose 1-4 N-acetyl-D-glucosamine structures were present and that fucose was included in these oilgosaccharide moieties. Sialic acid was not found in either subunit.

• Journal of Dairy Science and Biotechnology
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• 제19권1호
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• pp.39-48
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• 2001

As the development of medical technology and the elevation of the standard of living, the population rate of elderly people in Korea is increasing gradually. To keep a good lift quality of the elderly, both appropriate exercise and nutrients intake are necessary for them. Dairy products are known for the good source of variable nutrients including functional components and bioactive peptides such as Ig, lactoferrin, MFGM, OPP, CPP, GMP, sialic acid etc that are required especially for elderly people. However, they are classified as the low dairy products consumption group recently. For the promotion of dairy product consumption of elderly people, variable and specialized dairy products for the elderly should be researched and developed with the strengthened publicity activities.

• Journal of Microbiology and Biotechnology
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• 제9권3호
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• pp.361-364
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• 1999

The binding characteristics of Anagrapha falcifera nuclear polyhedrosis virus (AtNPV) to Spodoptera frugiperda 21 (Sf21) cells were investigated. The cells displayed an affinity of 4.7×10/sup 10/M/sup -1/ with about 3,300 binding sites per cell. The biochemical nature of the AfNPV-binding sites on the cell surface was also partially identified. Our findings suggest that the binding-site moiety has a glycoprotein component, but that the direct involvement of oligosacccharides containing N-acetylglucosamine or sialic acid residues in binding is unlikely, and that AfNPV entry into Sf21 cells may be via receptor-mediated endocytosis.

• Journal of Dairy Science and Biotechnology
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• 제17권1호
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• pp.50-57
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• 1999

Milk is a first food for as long as the mammalian race has existed. A characteristic unique to mammal is their ability to secrete milk as a source of nutrients and immunological protection for their young. From a nutitrional viewpoint, milk has heen described as nature's most perfect food, owing mainly to its biological role as the only source of nutrition for the infant mammal. Milk is estimated to contain more than 100,000 molecular species, However, the average contents of milk can be simplified to 3.4% fat, 3.1% protein (80% casein protein and 20% whey protein), 4.5% lactose, and 0.7% ash. Chemically, milk is a very complex fluid rich in nutrients, antibodies, growth factors, antimicrobial components etc. This report will discuss functional properties of milk components, such as lactoferrin, opoid peptide, CPP, cGMP and sialic acid etc.

• Journal of Microbiology
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• 제33권4호
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• pp.289-294
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• 1995

The action mechanism of hemolysin rendering virulency of Vibrio anguilarum has not clarified as yet, even though there were several possible factors explained. We have studied hemolytic kinetics performed by hemolysin from V. anguillarum strain V7 as well as binding of hemolysin to RBC membrane. Maximal rate of hemolysis and duration of lag phase were directly and inversly correlated to the concentration of hemolysin used. Hemolysin molecules are known to bind consumptively with proper diameter, while other protectants with smaller diameter could not. In conclusion, hemolysin should bind irreversibly to RBC membrane exert hemolysis distorting osmotic pressure. The binding could be hindered by spatial structure of the RBC surfacem which might be caused by sialic acid.