• 미생물학회지
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• 제51권2호
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• pp.108-114
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• 2015

본 연구에서는 Streptomyces subrutilus P5의 생장과 세포내 외 철 함유 superoxide dismutase 활성을 비교 분석하여 철함유 superoxide dismutase의 분비 시점을 확인하고 분자 수준에서 이 효소의 분비에 관여하는 유전정보를 확인하고자 하였다. Streptomyces subrutilus P5의 균체 생장은 건체 중량을 측정하여 결정하였다. Glucose는 log phase에서 급격히 소모되어 24시간 후에 이르러 완전히 고갈되었다. 세포내의 철 함유 superoxide dismutase는 배양 후 3시간에 나타나며 세포외 철 함유 superoxide dismutase는 배양 후 7.5시간부터 나타난다. 따라서 superoxide dismutase는 용균에 의해서가 아니라 능동적인 분비기작에 의해서 세포 외로 분비된 것으로 추측할 수 있다. Streptomyces subrutilus P5의 sodF에는 signal peptide 유전정보가 존재하지 않았다. 그러나 sodF의 상류지역에서 다른 세균의 type III 분비단백질 유전자와 유사한 type III 분비상자가 발견되었다. Streptomyces 균주에서 type III 분비단백질이 존재할 가능성이 있음을 처음으로 제시하였다.

• Journal of Microbiology and Biotechnology
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• 제18권10호
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• pp.1648-1654
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• 2008

Superoxide dismutase (SOD) removes damaging reactive oxygen species from the cellular environment by catalyzing the dismutation of two superoxide radicals to hydrogen peroxide and oxygen. Extracellular superoxide dismutase (EC-SOD) is a tetramer and is present in the extracellular space and to a lesser extent in the extracellular fluids. Increasing therapeutic applications for recombinant human extracellular superoxide dismutase (rEC-SOD) has broadened interest in optimizing methods for its purification, with a native conformation of tetramer. We describe a solid phase refolding procedure that combines immobilized metal affinity chromatography (IMAC) and gel filtration chromatography in the purification of rEC-SOD from Escherichia coli. The purified rEC-SOD tetramer from the $Ni^{2+}$-column chromatography is refolded in Tris buffer. This method yields greater than 90% of the tetramer form. Greater than 99% purity is achieved with further purification over a Superose 12PC 3.2/30 column to obtain the tetramer and specific activities as determined via DCFHDA assay. The improved yield of rEC-SOD in a simple chromatographic purification procedure promises to enhance the development and therapeutic application of this biologically potent molecule.

• Molecules and Cells
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• 제39권3호
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• pp.242-249
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• 2016

A balance between production and degradation of reactive oxygen species (ROS) is critical for maintaining cellular homeostasis. Increased levels of ROS during oxidative stress are associated with disease conditions. Antioxidant enzymes, such as extracellular superoxide dismutase (EC-SOD), in the extracellular matrix (ECM) neutralize the toxicity of superoxide. Recent studies have emphasized the importance of EC-SOD in protecting the brain, lungs, and other tissues from oxidative stress. Therefore, EC-SOD would be an excellent therapeutic drug for treatment of diseases caused by oxidative stress. We cloned both the full length (residues 1-240) and truncated (residues 19-240) forms of human EC-SOD (hEC-SOD) into the donor plasmid pFastBacHTb. After transposition, the bacmid was transfected into the Sf9-baculovirus expression system and the expressed hEC-SOD purified using FLAG-tag. Western blot analysis revealed that hEC-SOD is present both as a monomer (33 kDa) and a dimer (66 kDa), as detected by the FLAG antibody. A water-soluble tetrazolium (WST-1) assay showed that both full length and truncated hEC-SOD proteins were enzymatically active. We showed that a potent superoxide dismutase inhibitor, diethyldithiocarbamate (DDC), inhibits hEC-SOD activity.

• Archives of Plastic Surgery
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• 제40권5호
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• pp.517-521
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• 2013

Background Diabetes is characterized by chronic hyperglycemia, which can increase reactive oxygen species (ROS) production by the mitochondrial electron transport chain. The formation of ROS induces oxidative stress and activates oxidative damage-inducing genes in cells. No research has been published on oxidative damage-related extracellular superoxide dismutase (EC-SOD) protein levels in human diabetic skin. We investigated the expression of EC-SOD in diabetic skin compared with normal skin tissue in vivo. Methods The expression of EC-SOD protein was evaluated by western blotting in 6 diabetic skin tissue samples and 6 normal skin samples. Immunohistochemical staining was also carried out to confirm the EC-SOD expression level in the 6 diabetic skin tissue samples. Results The western blotting showed significantly lower EC-SOD protein expression in the diabetic skin tissue than in the normal tissue. Immunohistochemical examination of EC-SOD protein expression supported the western blotting analysis. Conclusions Diabetic skin tissues express a relatively small amount of EC-SOD protein and may not be protected against oxidative stress. We believe that EC-SOD is related to the altered metabolic state in diabetic skin, which elevates ROS production.

• BMB Reports
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• 제44권1호
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• pp.40-45
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• 2011

Extracellular superoxide dismutase (EC-SOD) is an antioxidant enzyme that protects cells and tissues from extracellular damage by eliminating superoxide anion radicals produced during metabolism. Two different forms of EC-SOD exist, and their different enzyme activities are a result of different disulfide bond patterns. Although only two folding variants have been discovered so far, five folding variants are theoretically possible. Therefore, we constructed five different mutant EC-SOD expression vectors by substituting cysteine residues with serine residues and evaluated their expression levels and enzyme activities. The mutant EC-SODs were expressed at lower levels than that of wild-type EC-SOD, and all of the mutants exhibited inhibited extracellular secretion, except for C195S ECSOD. Finally, we demonstrated that co-expression of wild-type EC-SOD and any one of the mutant EC-SODs resulted in reduced secretion of wild-type EC-SOD. We speculate that mutant EC-SOD causes malfunctions in systems such as antioxidant systems and sensitizes tissues to ROS-mediated diseases.

• BMB Reports
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• 제48권2호
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• pp.91-96
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• 2015

Cells express several antioxidant enzymes to scavenge reactive oxygen species (ROS) responsible for oxidative damages and various human diseases. Therefore, antioxidant enzymes are considered biomedicine candidates. Among them, extracellular superoxide dismutase (SOD3) had showed prominent efficacy against asthma and inflammation. Despite its advantages as a biomedicine, the difficulty in obtaining large quantity of active recombinant human SOD3 (rhSOD3) has limited its clinical applications. We found that a significant fraction of over-expressed rhSOD3 was composed of the inactive apo-enzyme and its potency against inflammation depended on the rate of metal incorporation. Also, purified rhSOD3 was unstable and lost its activity very quickly. Here, we suggest an ideal preparative method to express, purify, and store highly active rhSOD3. The enzymatic activity of rhSOD3 was maximized by incorporating metal ions into rhSOD3 after purification. Also, albumin or polyethylene glycol prevented rapid inactivation or degradation of rhSOD3 during preparative procedures and long-term storage.

• BMB Reports
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• 제46권8호
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• pp.404-409
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• 2013

Extracellular superoxide dismutase (EC-SOD) is a metallo-protein and functions as an antioxidant enzyme. In this study, we used lentiviral vectors to generate transgenic chickens that express the human EC-SOD gene. The recombinant lentiviruses were injected into the subgerminal cavity of freshly laid eggs. Subsequently, the embryos were incubated to hatch using phases II and III of the surrogate shell ex vivo culture system. Of 158 injected embryos, 16 chicks (G0) hatched and were screened for the hEC-SOD by PCR. Only 1 chick was identified as a transgenic bird containing the transgene in its germline. This founder (G0) bird was mated with wild-type hens to produce transgenic progeny, and 2 transgenic chicks (G1) were produced. In the generated transgenic hens (G2), the hEC-SOD protein was expressed in the egg white and showed antioxidant activity. These results highlight the potential of the chicken for production of biologically active proteins in egg white.

• 식물조직배양학회지
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• 제24권1호
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• pp.57-61
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• 1997

Superoxide dismutase (SOD) 고생산세포주로 선발된 토마토(Lycopersicun esculentum) 배양세포를 사용하여 현탁배양에 따른 SOD 활성과 isoenzyme변화를 조사하고 토마토 식물체의 것과 비교하였다. 현탁배양은 세포생중량 2 g을 1 mg/L 2,4-D, 30 g/L sucrose를 함유한 MS 배지 50 mL과 함께 mL flask에서 $25^{\circ}C$암상태로 배양(100 rpm)하였다. 세포생장은 계대배양후 20일에 최고점에 도달한 후, 급격히 감소하며 배양 후 23일부터 세포가 검게 변하였다. 세포 단위무게당 SOD활성(unit/g dry cell wt)은 배양 후 23일부터 증가하여 28일째에 최고활성(52,400 unit)을 나타낸 후 급격히 감소하였다. 세포 밖으로 분비되는 extracellular SOD활성은 배양 후 25일에 최고치(27,800 unit/so mL medium)를 나타낸 후 감소하였다. Flask 전체의 SOD활성은 배양 후 25일에 최대치(35,700 unit)를 나타내었으며 extracellular SOD 활성이 약 75%을 차지하였다. 토마토 배양세포에는 4개의 SOD isoenzyme이 존재하며, isoenzyme의 패턴변화는 세포생장에 따른 효소활성의 변화와 일치하였다. 토마토 식물체는 배양세포에 없는 CuZnSOD가 존재하며 배양세포와 식물체 조직사이에는 서로 다른 isoenzyme 패턴이 존재함을 알 수 있었다.

• Journal of Periodontal and Implant Science
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• 제36권1호
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• pp.97-112
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• 2006

유리 라디칼과 활성 산소종, 산화방지제 간의 불균형이 염증성 구강내 질환의 발생과 진행에 있어 중요한 역할을 한다는 주장이 제기되었고 최근에는 만성 염증성 치주질환에서도 산화에 의한 소실이 관찰되었다. 다양한 내적인 항산화 방어 기전 중 superoxide dismutase 가 $O_2$를 $H_2O_2$로 효과적으로 전환시킴으로써 활성산소종에 대한 일차적인 방어를 맡고 있다. 현재까지 인간에서 발견된 superoxide dismutase 는 cytoplasmic copper-zinc SOD와 mitochondrial manganase SOD, extracellular SOD의 3가지 아형이다. 이번 연구는 만성 치주질환을 가전 환자의 치주조직에서 효소 항산화제인 SOD의 발현정도를 알아봄으로써 질환조직 내의 산화자극 정도를 평가해 보고자하였다. 전남대학교 치주과에 내원한 33명의 만성 치주질환자와 20명 의 임상적으로 건강한 대상으로부터 조직을 얻어 Cu/Zn-SOD와 Mn-SOD, EC-SOD를 이용한 면역조직화학 염색을 시행하였다. 임상적 소견과 조직학적 소견이 일치하지 않아 조직학적 소견을 기준으로 건강한 조직, 경도, 중등도, 중도 치주질환 조직으로 그룹을 나누고 완전한 상피와 결합조직을 가진 27개의 표본에 대한 분석을 시행하였다. 치주질환 조직에서 건강한 조직에 비해 Cu/Zn-SOD가 상피의 기저층과 상피에 근접한 결합조직에서 발현되고 Mn-SOD는 염증이 증가함에 따라 크게 상피의 과립증과 각화층, 그리고 상피에 근접한 결합조직에서 발현됨으로써 활성산소종이 치주조직 파괴에 관여한다는 것을 알 수 있었다. 세 아형 모두 혈관주위에서 발현되었고 특히 EC-SOD는 작은 모세혈관주위에서만 발현되었으나 염증에 의해 혈관벽이 두꺼워지고 혈관 수가 증가한 곳에서 뚜렷하게 염색되었다. 이번 연구는 염증성 치주조직내 증가된 SOD의 활성이 치주질환자의 산화자극 정도와 관련되어 있음을 시사하였다.

• Reproductive and Developmental Biology
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• 제30권4호
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• pp.229-234
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• 2006

We have generated transgenic mice that expressed mouse extracellular superoxide dismutase (EC-SOD) in their skin. In particular, the expression plasmid DNA containing human keratin K14 promoter was used to direct the keratinocyte-specific transcription of the transgene. To compare intron-dependent and intron-independent gene expression, we constructed two vectors. The vector B, which contains the rabbit -globin intron 2, was not effective for mouse EC-SOD overexpression. The EC-SOD transcript was detected in the skin, as determined by Northern blot analysis. Furthermore, EC-SOD protein was detected in the skin tissue, as demonstrated by Western blot analysis. To evaluate the expression levels of EC-SOD in various tissues, we purified EC-SOD from the skin, lungs, brain, kidneys, livers, and spleen of transgenic mice and measured its activities. EC-SOD activities in the transgenic mice skin were approximately 7 fold higher than in wild-type mice. These results suggest that the mouse overexpressing vector not only induces keratinocyte-specific expression of EC-SOD, but also expresses successfully functional EC-SOD. Thus, these transgenic mice appeared to be useful for the expression of the EC-SOD gene and subsequent analysis of various skin changes, such as erythema, inflamation, photoaging, and skin tumors.