• Journal of Pharmaceutical Investigation
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• 제38권2호
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• pp.93-98
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• 2008

The drug-eluting stent (DES) implantation is a widely acceptable treatment for coronary heart disease. It was reported that iron chelator had anti-proliferative effect on human vascular smooth muscle cells (HA-VSMCs). In this study, tetraphenylporphine (TPP) was selected as an iron chelator and drug for DES. MTT assay showed that TPP had antiproliferative effect on HA-VSMCs. TPP and polycaprolactone (PCL) were coated onto stainless steel plate using a spraycoating method. From the surface morphology examination of the coated plate by SEM, smooth polymer coating layer could be observed. The thickness of coating layer could be controlled by changing repeating time of coating. From in vitro release test, sustained release of TPP was observed from plate during two weeks. Thus, TPP as iron chelator can be used as drug for stent coating because of its antiproliferative effect and sustain release profile.

• Journal of Microbiology and Biotechnology
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• 제18권8호
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• pp.1357-1363
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• 2008

The $P_{entC}$ promoter of the entCERA operon encoding enzymes for enterobactin biosynthesis in Escherichia coli is tightly regulated by the availability of iron in the culture medium. In iron-rich conditions, the $P_{entC}$ promoter activity is strongly repressed by the global transcription regulator Fur (ferric uptake regulator), which complexes with ferrous ions and binds to the Fur box 19-bp inverted repeat. In this study, we have constructed the expression vector pOS2 containing the $P_{entC}$ promoter and characterized its repression, induction, and modulation by quantifying the expression of the lacZ reporter gene encoding $\beta$-galactosidase. $\beta$-Galactosidase activities of E. coli transformants harboring pOS2-lacZ were highly induced in the presence of divalent metal ion chelators such as 2,2'-dipyridyl and EDTA, and were strongly repressed in the presence of excess iron. It was also shown that the basal level $\beta$-galactosidase expression by the $P_{entC}$ promoter was drastically decreased by incorporating the fur gene into the expression vector. Since the newly developed iron chelator-inducible expression system is efficient and cost-effective, it has wide applications in recombinant protein production.

• Bulletin of the Korean Chemical Society
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• 제25권12호
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• pp.1889-1892
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• 2004

The peroxidase activity of cytochrome c was studied by using a chromogen, 2,2'-azinobis-(2-ethylbenzthiazoline-6-sulfonate) (ABTS). Initial rate of ABTS oxidation formation was linear with respect to the concentration of cytochrome c between 2.5-10 ${\mu}$M and $H_2O_2$ between 0.1-0.5 mM. The optimal pH for the peroxidase activity of cytochrome c was 7.0-8.5. The peroxidase activity retained about 40% of the maximum activity when exposed at 60 $^{\circ}C$. for 10 min. The peroxidase activity showed a typical Michaelis-Menten kinetics for $H_2O_2$ which Km value was 29.6 mM. Radical scavengers inhibited the peroxidase activity of cytochrome c. The peroxidase activity was significantly inhibited by the low concentration of iron chelator, deferoxamine. The results suggested that the peroxidase activity was associated with iron in the heme of cytochrome c.

• 한국어병학회지
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• 제22권3호
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• pp.239-251
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• 2009

배양 온도, 배양 배지 중의 pH, NaCl 농도, iron 농도와 같은 배양 조건이 P. damselae의 미생물학적 성상 및 병원성에 미치는 영향을 조사하였다. P. damselae는 배양 온도 15-30${^{\circ}C}$에서 배지의 pH 5-9, NaCl 농도 0-6%와 $FeCl_{3}$ 첨가시 성장이 촉진되었지만, iron-chelator 첨가 시성장이 억제되었다. Iron-limited 조건에서 배양시 ECPs protein 농도, phospholipase, 용혈능, siderophore 및 cytotoxicity 활성 이 높게 나타났고, 넙치 혈청의 살균작용 대한 생존율도 증가 되었으나, iron-added 조건에서는 감소되어, 배양 조건 중 iron 농도에 영향을 가장 많이 받는 것으로 나타났다. 따라서, 본 연구에서 적용한 iron-limited 조건은 철농도가 낮은 숙주 내와 유사한 환경이므로 iron-limited에서 P. damselae 배양 시 나타나는 병원성의 증가는 어체에 감염시 나타나는 병원성 발현 기전과 유사할 것으로 사료된다.

• Archives of Pharmacal Research
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• 제18권3호
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• pp.159-163
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• 1995

Previously, we have reported that methylene blue (MB) induces cytotoxicity in human brain tumor cells through the generation of free radicals. In this study the effect of deferoxamine (DFO), an iron chelator, on MB-induced cytotoxicity was investigated using SK-N-MC human neuroblastoma and U-373 MG human astrocytoma cells as model cellular systems. The cytotoxic effect of MB was potentiated by DFO. The potentiation effect of DFO was significantly blocked by either stoichiometric amounts of ferric ion, various antioxidants, hydroxyl radical scavengers or intracellular $Ca^{2+}$ release blockers. These results suggest that hydroxyl radical and intracellular $Ca^{2+}$ may act as important mediators of the enhanced cytotoxicity by MB and DFO. These results further suggest that the combined treatment with MB and DFO may be useful for the therapeutical applications of human brain tumors.

• 미생물학회지
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• 제51권3호
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• pp.249-255
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• 2015

철 스트레스($2{\mu}M$ 이하 농도) 하에서 시데로포어를 생산하는 균주를 토양에서 분리하여 16S rDNA 염기 서열 분석과 생화학적, 생리학적 분석 및 전자 현미경 관찰 등으로 동정한 결과, Acinetobacter sp.로 밝혀졌다. 시데로포어의 카테콜 특성은 Arnow법으로 조사되었다. 철을 제한한 배지에서 균주를 배양한 결과, $36^{\circ}C$에서도 잘 자랐지만 시데로포어 생산은 $28^{\circ}C$에서 높았다. $36^{\circ}C$에서는 시데로포어 생산이 강하게 억제되었다. $10{\mu}M\;FeCl_3$를 첨가한 배지에서는 시데로포어 생산이 완전히 억제되었다. 균주 상등액을 부탄올 추출 후, Sephadex LH-20 컬럼 크로마토그래피와 HPLC를 이용하여 시데로포어를 분리, 정제하였다. 분리, 정제된 시데로포어의 구조는 HPLC, TLC와 IR 분석 결과로부터 2,3-dihydroxybenzoic acid로 확인되었다.

• Journal of Microbiology and Biotechnology
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• 제7권5호
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• pp.352-355
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• 1997

The promoter region of the pupA gene of Pseudomonas putida WCS358 was fused with the structural genes for bioluminescence (luxCDABE) from Vibrio fischeri, and the resulting fusion plasmid harbored by the WCS358 host. The pup-lux fusion gene was then used for quantitative analysis of the iron-dependence of pupA promoter activity. Factors affecting bioluminescence produced by the pup-lux bioreporter were found to be cell activity, iron-chelator concentrations, Fe(III) concentrations, and nutrient components. Light production rates of the pup-lux bioreporter were inversely dependent upon iron molecules when $FeCl_3$ concentrations were between $10^{-2}$ and 1 ${\mu}M$ in nutrient-poor minimal media, and between 0.1 and 10 mM in nutrient-rich complex media.

• BMB Reports
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• 제46권2호
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• pp.119-123
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• 2013

Methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline (salsolinol), an endogenous neurotoxin, is known to perform a role in the pathogenesis of Parkinson's disease (PD). In this study, we evaluated oxidative modification of cytochrome c occurring after incubation with salsolinol. When cytochrome c was incubated with salsolinol, protein aggregation increased in a dose-dependent manner. The formation of carbonyl compounds and the release of iron were obtained in salsolinol-treated cytochrome c. Salsolinol also led to the release of iron from cytochrome c. Reactive oxygen species (ROS) scavengers and iron specific chelator inhibited the salsolinol-mediated cytochrome c modification and carbonyl compound formation. It is suggested that oxidative damage of cytochrome c by salsolinol might induce the increase of iron content in cells, subsequently leading to the deleterious condition which was observed. This mechanism may, in part, provide an explanation for the deterioration of organs under neurodegenerative disorders such as PD.

• Bulletin of the Korean Chemical Society
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• 제34권11호
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• pp.3295-3300
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• 2013

Acrolein (ACR) is a well-known carbonyl toxin produced by lipid peroxidation of polyunsaturated fatty acids, which is involved in the pathogenesis of neurodegenerative disorders such as Alzheimer's disease (AD). In Alzheimer's brain, ACR was found to be elevated in hippocampus and temporal cortex where oxidative stress is high. In this study, we evaluated oxidative modification of cytochrome c occurring after incubation with ACR. When cytochrome c was incubated with ACR, protein aggregation increased in a dose-dependent manner. The formation of carbonyl compounds and the release of iron were obtained in ACR-treated cytochrome c. Reactive oxygen species scavengers and iron specific chelator inhibited the ACR-mediated cytochrome c modification and carbonyl compound formation. Our data demonstrate that oxidative damage of cytochrome c by ACR might induce disruption of cyotochrome c structure and iron mishandling as a contributing factor to the pathology of AD.

• Bulletin of the Korean Chemical Society
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• 제34권2호
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• pp.406-410
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• 2013

Tetrahyropapaveroline (THP) is compound derived from dopamine metabolism and is capable of causing dopaminergic neurodegenerative disorder, such as Parkinson's disease (PD). The aim of this study was to evaluate the potential of THP to cause oxidative damage on the structure of cytochrome c (cyt c). Our data showed that THP led to protein aggregation and the formation of carbonyl compound in protein aggregates. THP also induced the release of iron from cyt c. Reactive oxygen species (ROS) scavengers and iron specific chelator inhibited the THP-mediated cyt c modification and carbonyl compound formation. The results of this study show that ROS may play a critical role in THP-induced cyt c modification and iron releasing of cyt c. When cyt c that has been exposed to THP was subsequently analyzed by amino acid analysis, lysine, histidine and methionine residues were particularly sensitive. It is suggested that oxidative damage of cyt c by THP might induce the increase of iron content in cells and subsequently led to the deleterious condition. This mechanism is associated with the deterioration of organs under neurodegenerative disorder such as PD.