• Animal cells and systems
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• 제7권1호
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• pp.81-87
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• 2003

While screening proteins that interact with DnaA protein, the initiator protein for Escherichia coil chromosomal DNA replication, we found a 52-kD sized protein which bound to DnaA protein in a salt-dependent manner. This protein was identified as trigger factor, a ribosome-associated peptidyl-prolyl- cisltrans isomerase with chaperone activity. Trigger factor was overproduced and purified to near homogeneity, and its effect on the function of DnaA protein was examined, Enhanced binding of DnaA protein to DnaA box with no apparent supershift in the gel-shift experiments suggested that trigger factor, by virtue of its chaperone activity, exerts a change on DnaA protein thus increasing its binding affinity for DnaA box.

• Korean Chemical Engineering Research
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• 제60권3호
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• pp.398-406
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• 2022

그람음성균의 외막은 수많은 생물물리학적 및 생화학적 과정이 작용하여 생존력을 유지하도록 설계되어 있는 세포환경의 가장 바깥 층이다. 세포공학의 발전으로 인해 박테리아의 막 환경을 변경하는 등 유전정보를 원하는 대로 조작할 수 있게 되었고 이는 박테리아를 특정 목적에 적용시킬 수 있게 하였다. 그중 기능성 분자를 박테리아 외막에 표지하는 세포 표면공학은 숙주세포가 특정 외부물질이나 자극에 반응하도록 유도하는 전략 중 하나이다. 기능성 펩타이드 또는 단백질을 세포 표면에 표지하기 위한 방법으로 막 고정 모티프를 융합한 후 세포 내에서 발현하는 방법이 일반적으로 사용되고 있지만 이는 박테리아 시스템에서 발현할 수 없는 외인성 단백질이나 크기가 큰 단백질에는 적용할 수 없다는 한계점이 있다. 박테리아 외막의 구성요소에 자연적으로 존재하는 반응성 그룹과 기능성 물질을 화학접합하는 방법도 있으나 필수 구성 요소의 비특이적 변형으로 인해 세포의 생장이 저해되는 경우가 많다. 본 연구에서는 비천연아미노산 또는 자가결합 도메인을 사용해 대장균의 세포 표면을 부위 특이적으로 형광 표지하는 두 가지의 접근법을 수행하였다. 첫 번째 접근법은 화학선택적 반응성을 지닌 비천연아미노산이 삽입된 펩타이드를 대장균 표면에 발현하여 위치 특이적으로 형광염료를 접합시키는 방법이다. 두 번째 접근법은 자가결합능력을 지닌 이종 이량체 코일-코일에서 유래된 α-나선 도메인을 대장균 외막에 발현하고 녹색 형광 단백질이 융합된 상보적인 α-나선 도메인을 막 표면에 특이적으로 고정하는 방법이다. 제시된 방법들은 위치와 시간이 제어된 방식으로 박테리아 외막에 새로운 기능을 부여하는 방법론으로서 유용하다.

• Journal of Life Science
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• 제11권1호
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• pp.1-6
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• 2001

In order to determine the role of the carboxyl terminal amino acid residues of unacetylated ${\alpha}$-tropomyosin in actin affinity two mutant tropomyosins were constructed by site-directed mutagenesis. TM16 was identical to the striated tropomyosin except that three amino acids in the carboxyl terminal end were altered to $^{282}TNM^{284}$ while in TM17 $^{282}TSI^{284}$ of the striated was replaced with$^{282}NSM^{284}$. TM16 and TM17 were overproduced in Escherichia coli and analyzed for actin affinity by comparing actin affinities of the striated and TM11 $^{282}NNM^{284}$). The apparent binding constants (Kapp) of unacetylated tropomyosins to actin were $5.1{\times}10^4M^{-1}$ for the striated, $1.1{\times}10^5M^{-1}$ for TM11, $1.09{\times}10^5M^{-1}$ for TM16, and $1.03{\times}10^5M^{-1}$ for TM17, respectively. Since the actin affinities of TM11, TM16, and TM17 were very similar, this result suggested that amino acid residues 282 and 283 were insignificant for acting affinity of unacetylated $\alpha$-tropomyosin. However, they all exhibited higher actin affinities than that of the striated, suggesting that Met residue at the carboxyl terminus of unacetylated smooth tropomyosin was rather important for actin affinity, presumably due to the nucleophilic nature of sulfur atom in Met residue.

• 동의생리병리학회지
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• 제17권6호
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• pp.1427-1432
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• 2003

This study was carried out to investigate the antimicrobial and anticancer effects of Galla Rhois (GR) on pathogens isolated from oral and KB human oral epidermoid carcinoma cells. Their antimicrobial activities were tested against Streptococcus mutans (S. mutans), Staphylococcus aureus (S. aureus), Enterobacter aerogenes (E. aerogenes), Escherichia coli (E. coil) and Candida albicans (C. albicans). GR powder has the antimicrobial activity against C. albicans, S. mutans and S. aureus. The extracts of water and ethanol have the antimicrobial activity against S. sureus and C. albicans. The water extract showed inhibitory activity against the growth and pH of above mentioned reference microorganisms. The water extract of GR declined cell viability in a dose dependent manner. DNA flow cytometric analysis showed that population of sub-G/sub 0//G₁, phase of cell cycle was increased by GR extract treatment in a dose dependent manner. Western blot analysis revealed that Caspase-3 was reduced by GR extract treatment. These result suggested that GR has the effect of antimicrobial on pathogens isolated from oral, and also, has anticancer effect that associated with the induction of apoptosis in a dose dependent manner in KB human oral epidermoid carcinoma cells. It may be GR-induced apoptosis was mediated via activation of Caspase-3.

• Journal of Microbiology
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• 제40권1호
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• pp.77-81
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• 2002

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a pleiotropic hematspoietic growth factor involved in the development of myeloid cells from bone marrow, and an activator of mature myeloid cells functioning in a variety of antimicrobial and inflammatory responses. Recently, recombinant GM-CSF is increasingly under clinical study for treatment of various diseases including cancer, infectious diseases and hematopoietic diseases as well as for an immune response modulator, In this study, we constructed a recombinant human GM-CSF (rhGM-CSF) expression plasmid with a pelB leader sequence and His. Tag under T7 promoter control. The expression construct was shown to produce a recombinant protein of 20 kDa in the 8M urea preparation, indicating the rhGM-CSF may be expressed as an insoluble inclusion form. The 20 kDa recombinant protein in 8M urea was transformed into the water-so1ub1e form by dialysis against PBS buffer (phosphate buffered saline). The soluble rhGM-CSF protein was shown to stimulate colony formation and cell proliferation in vitro, indicating that the rhGM-CSF could be refolded into its native form to show colony stimulating activity.

• BMB Reports
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• 제40권3호
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• pp.412-418
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• 2007

Phospholipid hydroperoxide glutathione peroxidase (PHGPx) is an unique antioxidant enzyme that directly reduces lipid hydroperoxides in biomembranes. In the present work, the entire encoding region for Oryza sativa PHGPx was expressed in Escherichia coli M15, and the purified fusion protein showed a single band with 21.0 kD and pI = 8.5 on SDS- and IFE-PAGE, respectively. Judging from CD and fluorescence spectroscopy, this protein is considered to have a well-ordered structure with 12.2% $\alpha$-helix, 30.7%$\beta$-sheet, 18.5% $\delta$-turn, and 38.5% random coil. The optimum pH and temperature of the enzyme activity were pH 9.3 and 27$^{\circ}C$. The enzyme exhibited the highest affinity and catalytical efficiency to phospholipid hydroperoxide employing GSH or Trx as electron donor. Moreover, the protein displayed higher GSH-dependent activity towards t-Butyl-OOH and $H_2O_2$. These results show that OsPHGPx is an enzyme with broad specificity for hydroperoxide substrates and yielded significant insight into the physicochemical properties and the dynamics of OsPHGPx.

• 한국미생물·생명공학회지
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• 제9권3호
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• pp.165-171
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• 1981

E. coil ATCC 9637의 균체를 젤라틴과 DEAE-cellulose의 혼합 성형 후 글루트알데히드 가교법으로 제조론 고정화 penicillin amidase의 differential column reactor에서의 반응속도를 논의하였다. 이러한 반응조의 최적 조작조건은 효소충진량 1g, 기질농도30mM(0.1M 인산완충액, pH8.0), 유출속도 4 $m\ell$/min, 온도 4$0^{\circ}C$이었다. 이 최적조건에서 고정화효소의 일반적인 성질을 조사하였다. Km 상수는 4.8mM 이었고 specific activity 308 units/g 고정화 효소이 었다. 또한 고정화효소에서는 기질에 의한 효소반응 저해효과가 보이지 않았다. 이러한 differential column reactor에서는 column내에서의 pH 감소효과 및 외부 화산효과가 없어지기 때문에 이러한 외부적 영향을 받지 않는 고정화효소의 반응 속도론적 연구에 적합함을 알았다.

• 대한한방부인과학회지
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• 제20권1호
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• pp.1-15
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• 2007

Purpose : This study was conducted to investigate the antimicrobial effects of herb for removing dampness and promoting urination against vaginal microbes. Methods : Staphylococcus aureus. Methicillin-resistant Staphylococcus aureus(MRSA), Candida albicans and Gardnerella vaginalis were used for vaginitis-induced microbes. Lactobacillus gasseri, Streptococcus spp. and Escherichia coil HB101 were used for normal vaginal florae. And herbs for removing dampness and promoting urination(Dianthi herbs. Tokoro Rhizoma, Saururi Herbs, Pyrrosiae Folium, Artemisiae Iwayomogii Herba, Plantaginis Semen, Tetrapanacis Medulla, Polygoni Avicularis Herba, Malvae Semen, Akebiae Caulis, Kochiae Fructus, Lygodii Spora) were used. Antimicrobial activities were estimated by the change of optical densities and colony test in vitro. Results : Plantaginis Semen, Artemisiae Iwayomogii Herba and Lygodii Spora had the antimicrobial susceptibility and selective toxicity against MRSA and Gardnerella vaginalis. Polygoni Avicularis Herba had the antimicrobial susceptibility and selective toxicity against Staphylococcus aureus. MRSA and Gardnerella vaginalis. Malvae Semen and Kochiae Fructus had the antimicrobial susceptibility and selective toxicity against MRSA. Dianthi Herba had the antimicrobial susceptibility and selective toxicity against Gardnerella vaginalis. Conclusion : According to these results, we can suggest that Plantaginis Semen, Artemisiae Iwayomogii Herba, Lygodii Spora, Polygoni Avicularis Herba, Malvae Semen, Kochiae Fructus and Dianthi Herba would be available to the antimicrobial agent for vaginitis-induced microbe in vitro.

• Journal of Microbiology
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• 제40권2호
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• pp.156-160
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• 2002

The whole gal/lae operon genes of Lactococcus lactis ssp. lactis 7962 were reported as follows: galA-galM-galK-galT-lacA -lacZ-galE. The galK gene encoding a galactokinase involved in one of the Leloir pathways for galactose metabolism was found to be 1,197 bp in length and encodes a protein of 43,822 Da calculated molecular mass. The deduced amino acid sequence showed over 50% homology with GaIK proteins from several other lactic acid bacteria. The galK gene was expressed in E. coli and the product was identified as a 43 kDa protein which corresponds to the estimated size from the DNA sequence. The galactokinase activity of recombinant 5. coli was about 8 times greater against that of the host strain and more than 3 times higher than the induced L. lactis 7962.

• KSBB Journal
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• 제21권2호
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• pp.129-132
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• 2006

Artemisia princes var. orientalis의 수용성 추출물이 식품, 화장품, 의약품 등의 항균제로 이용될 수 있는지에 대해 연구 하였다. 순수한 물을 이용한 추출물에서는 항균성을 찾기 힘들었고, 쑥의 줄기와 잎 부분에서 메탄올로 추출한 후 물로 추출한 물이 Staphylococcus aureus에 대해서 항균성을 크게 나타냈으며, 잎이 줄기 부분보다 더 큰 항균성을 나타냄을 확인했다. 항균성을 갖는 물질을 밝혀내기 위해 쑥의 주된 항균 성분이라 알려진 caffeic acid와 비교 실험을 하였다. UV 특성곡선에서 caffeic acid와 유사한 phenolic compound의 profiling은 확인할 수 있었으나 caffeic acid의 disc diffusion method를 이용한 실험에서는 항균능력을 나타내지 않았다. 물질규명을 위해 추출물을 세 부분으로 분획 하였고, 이 중에서 Staphylococcus aureus에 대해 항균성은 UK 2에서 크게 나타났다. 본 연구는 Artemisia princeps var. orientalis 의 메탄올 후 물 추출물이 항균제로써의 가능성을 알아봄으로써 식품 또는 화장품의 보존료나 항균제의 이용성이 있음을 충분히 확인하였다.