• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.264.1-264.1
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• 2003

In order to search for the anti-HIV agents from natural products, Eighty MeOH extracts of medicinal plants were applied to a syncytia formation inhibition assay which is based on the interaction between the HIV-1 envelope glycoprotein gp120/gp41 and the cellular membrane protein CD4 of T lymphocytes. Among them, Ailanthus altissima showed a potent virus-cell fusion inhibitory activity. (omitted)

• Archives of Pharmacal Research
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• 제24권6호
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• pp.514-517
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• 2001

In order to find potent virus-cell fusion inhibitory components from Korean edible clams, thirteen prepared polysaccharides were introduced to syncytia formation inhibition assay, which is based on the interaction between the HIV-1 envelope protein gp 120/41 and the cellular membutane protein CD4 of T lymphocytes. Among them, Meretrix petechialis showed a potent viruscell fusion inhibitory activity. Fusion index (F1) and percent (%) fusion inhibition of the polysaccharide of this clam were $0.21{\pm}0.02$, and $67.52{\pm}4.09$ at 100781m1, respectively. It exhibited almost equivalent virus-cell fusion inhibitory activity to that of dextran sulfate which was used as a standard control.

• 생명과학회지
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• 제27권3호
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• pp.370-381
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• 2017

단백질 탈 인산화는 단백질 탈 인산화 효소에 의해 매개되는 과정으로 세포 생존에 매우 중요하다. 단백질 탈 인산화 효소 중에서 최근 CTD (carboxy-terminal domain) 탈 인산화 효소들이 등장하고 있으며 이들에 대한 새로운 생물학적 역할이 밝혀지고 있다. 이 효소의 그룹에는CTD 탈 인산화 효소 1(CTDP1), CTD 소형 탈 인산화 효소 1(CTDSP1), CTD 소형 탈 인산화 효소 2(CTDSP2), CTD 소형 탈 인산화 효소 유사(CTDSPL), CTD 소형 탈 인산화 효소 유사 2(CTDSPL2), CTD 핵 탈 인산화 효소(CTDNEP1) 및 유비퀴틴 유사 도메인 함유CTD 탈 인산화 효소 1(UBLCP1)들이 존재한다. CTDP1은 RNA 중합 효소 II (RNAPII)의 CTD의 두 번째 인산화 된 세린을 탈 인산화 시키고, CTDSP1, STDSP2 및 CTDSPL은 RNAPII의 CTD의 다섯 번째 인산화 된 세린을 탈 인산화 시킨다. 그리고 CTDSP1은 SMAD들, CDCA3, Twist1, 종양억제 단백질인 PML, c-Myc과 같은 새로운 기질을 탈 인산화 시키는 것으로 밝혀지고 있다. CTDP1은 유사 분열 조절 및 암세포 성장과 관련이 있다. CTDSP1, CTDSP2 및 CTDSPL은 종양 억제 기능 및 줄기 세포 분화와 관련이 있다. CTDNEP1은 LIPIN1을 탈 인산화 시키고 핵막 형성과 관련이 있다. CTDSPL2는 조혈 줄기 세포 분화와 관련이 있다. UBLCP1은 26S 프로테아좀을 탈 인산화 시키고 핵 프로테아좀 활성 조절과 관련이 있다. 결론적으로, CTD 탈 인산화 효소의 새로운 기능과 역할은 최근의 연구에서 밝혀지고 있으며, 이 리뷰는 CTD 탈 인산화 효소의 새롭게 밝혀진 역할들을 요약하고자 정리한 것이다.

• BMB Reports
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• 제29권2호
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• pp.175-179
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• 1996

Viral surface proteins are known to play an essential role in attachment of the virus particle to the host cell membrane. In case of the hepatitis B virus (HBV) several reports have described potential receptors on the target cell side, but no definite receptor protein has been isolated yet. As for the viral side, it has been suggested that the preS region of the envelope protein, especially the preS1 region, is involved in binding of HBV to the host cell. In this study, preS1 region was recombinantly expressed in the form of a maltose binding protein (MBP) fusion protein and used to identify and visualize the expression of putative HBV receptor(s) on the host cell. Using laser scanned confocal microscopy and by FACS analysis, MBP-preS1 proteins were shown to bind to the human hepatoma cell line HepG2 in a receptor-ligand specific manner. The binding kinetic of MBP-preS1 to its cellular receptor was shown to be temperature and time dependent. In cells permeabilized with Triton X-100 and treated with the fusion protein, a specific staining of the nuclear membrane could be observed. To determine the precise location of the receptor binding site within the preS1 region, several short overlapping peptides from this region were synthesized and used in a competition assay. In this way the receptor binding epitope in preS1 was revealed to be amino acid residues 27 to 51, which is in agreement with previous reports. These results confirm the significance of the preS1 region in virus attachment in general, and suggest an internalization pathway mediated by direct attachment of the viral particle to the target cell membrane.

• BMB Reports
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• 제29권2호
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• pp.180-182
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• 1996

One of the essential functions of virus surface proteins is the recognition of specific receptors on target cell membranes, and cellular receptors play an important role in viral pathogenesis. But the earliest steps of hepatitis B virus (HBV) infection, such as hepatocyte receptor interaction with the virus, are poorly understood. Previous work has suggested an important role of the preS1 region of HBV envelope protein in mediating viral binding to hepatocytes. Although hepatitis B virus (HBV) infection appears to be initiated by specific binding of virions to cell membrane structures via one or potentially several viral surface proteins, data showing the identification or isolation of the HBV receptor (s) are not yet available. The receptor-like proteins on the plasma membrane surface of HepG2 cells that bind to PreS1 were separated and identified using affinity chromatography, and the amino-terminal amino acid sequences of the receptor-like proteins were determined.

• 대한수의학회지
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• 제29권4호
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• pp.541-548
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• 1989

오제스키병 바이러스를 배양세포에다 감염시켜, 냉동 및 araldite포매 초박절편에서 protein A-gold labeling을 통해 바이러스항원 검출을 시도하였다. 오제스키병 바이러스항원은 10nm gold probes로 표지되었으며, 전자밀도가 높은 gold 입자들은 바이러스의 nucleocapsid와 envelope에서 주로 관찰되었고, 초냉동박절표본에서의 immunogold labeling은 조직구조물들과 극히 미미한 비특이결합만을 보였다. 초냉동박절표본에서의 immunogold labeling은 오제스키병 바이러스항원을 검출하는데 있어 효과적이었으며, 이는 또한 여러가지 바이러스들과 속주세포들간의 상호작용에 관한 면역세포화학적 연구에 크게 이용될 수 있을 것으로 생각된다.

• Journal of Microbiology
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• 제35권3호
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• pp.213-221
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• 1997

The secretion of the alkaliphilic Bacillus sp. S-1 extracellular pullulanase involves translocation across the cytoplasmic membrane of the Gram-positive bacterial cell envelope. Translocation of the intracellular pullulanase PUL-I, was traced to elucidate the mechanism and pathway of protein secretion from an alkaliphilic Bacillus sp. S-1. Pullulanase could be slowly bue quantitatively released into the medium during growth of the cells in medium contianing proteinase K. The released pullulanase lacked the N-terminal domain. The N-terminus is the sole membrane anchor in the pullulanase protein and was not affected by proteases, confirming that it is not exposed on the cell surface. Processing of a 180,000M$\_$r/ pullulanase to a 140,000M$\_$r/ polypeptide has been demonstrated in cell extracts using antibodies raised against 140,000M$\_$r/ extracellular form. Processing of the 180,000 M$\_$r/ protein occured during the preparation of extracts in an alkaline pH condition. A modified rapid extraction procedure suggested that the processing event also occured in vivo. Processing apparently increased the activity of pullulanase. The western blotting analysis with mouse anti-serum against 140-kDa extracellular pullulanase PUL-E showed that PUL-I is processed into PUL-X via intermediate form of PUL-E. Possible explanationa for the translocation are discussed.

• 미생물학회지
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• 제21권2호
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• pp.61-70
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• 1983

Synchronized cat kidney cells chronically infected with feline leukemia virus (FeLV) were used to study virus production, the synthesis of group specific antigen (gag) and envelope (env) proteins, the expression of env protein on the cell surface during the cell cycle, and the stability of viral RNA. As detecting method, we developed the radioimmunoassay (RIA) system using beta-emission of $^{131}I$ and demonstrated the validity of this system by comparison with routine RIA system using gamma-emission of $^{125}I$. The produced virus was analysed by developed RIA interval was determined by measuring reverse transcriptase activity. The results show that infected cells produce the complete virus particle containing products of gag, env and pol genes of FeLV, and maximum virus production occurs during mitosis of synchronized cells. Labeling of the cell surface of synchronized cells with $^{131}I$ shows that the amount of $gp70^{env}$ on the cell surface parallels cellular gorwth. Therefore, the cell cycle-dependent release of virus is not petition RIA of synchronized cells with $^{131}I$ labeled viral proteins synthesis during the cell cycle. The rate of synthesis of gag protein shows three peaks, corresponding to the $G_1,\;late\;S\;and\;late\;G_2$ phases of cell cycle. But the rate of synthesis of env protein dose not change, suggesting that in these cells the synthesis of these two gene products in controlled seperately. In Actionomycin D treated cells, the synthesis of viral proteins decreased sharply from 8 hours after treatment, and the late S and $G_2$ peaks of gag protein synthesis were disappeared. This shows the stability of viral RNA for about 6 hours in the absence of continuing viral RNA synthesis.

• 한국동물학회지
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• 제34권1호
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• pp.44-53
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• 1991

Distribution of the antigens during the cell cycle of amoebae was followed by immunof-luorescence microscopy using a monoclonal antibody against the nucleus as a probe. While the cells were in the interphase, the antigen was localized on the nucleus membrane. But it was dispersed all over the cytoplasm during mitosis and cytokinesis. The molecular weights of the immunoreacted antigens were 210 KD and 190 KD as determined by SDS PAGE and western blotting of the purified nuclei. The antigens were not soluble in non-ionic detergent, but were released from the nucleus by incubation with 0.05 M sodium carbonate, pH 10.6 or with 8 M urea at serial chemical extraction. Thus the antigens appeared to be peripheral proteins of the nurBeus envelope. The isoelectic point of both antigens was 7.64 as determined by 2 D PAGE and transfer blotting. Considering the peiipherd association with the nucleus membrane and the dispersed distribution during mitosis, the antigens could be lamin like proteins. Hourever, it appears also possible that they are the component molecules of the unusually structured aurous lamina of amoeba nucleus since they have the large molecular weight and the basic pl.

• 생약학회지
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• 제34권1호통권132호
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• pp.28-32
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• 2003

In order to search for the anti-HIV agents from natural products, eighty MeOH extracts of medicinal plants were applied to a syncytia formation inhibition assay which is based on the interaction between the HIV-1 envelope glycoprotein gp120/gp41 and the cellular membrane protein CD4 of T lymphocytes. Among them, Ailanthus altissima showed a potent virus-cell fusion inhibitory activity. Repeated column chromatoghaphy of the methylene chloride fraction of A. altissima afforded compounds 1$({\beta}-sitosterol-3-O-{\beta}-D-glucoside)$, 2(tetramethoxycoumarin), and 3(ocotillone). Virus-cell fusion inhibitory activity of compound 3(ocotillone) was $70.76{\pm}4.09%$ at the concentration of $100\;{\mu}g/ml$.