• 한국식품저장유통학회지
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• 제18권2호
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• pp.208-211
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• 2011

Limonoid는 항바이러스 및 항균제로써의 치료적인 목적으로 널리 연구되고 있는 성분으로 감귤에서 풍부하게 존재한다. 그러나 성분 자체의 쓴맛으로 인하여 기호성이 저하되므로 이를 해결하는 노력이 필요하며 제품 개발이 요구되고 있는 실정이다. 이러한 쓴맛을 제거할 수 있는 훌륭한 효소로써 LUGT가 주목되고 있으며, 이에 효소의 특성화 연구를 위하여 분리 및 정제를 시도하였다. Plasmid vector인 pET30a(+)을 사용하여 대장균에서 효소 생성 을 위한 최적 발현조건을 검토한 결과, 0.5 mM IPTG 조건에서 $37^{\circ}C$에서 5시간동안 배양하는 것이 최적 과발현 조건이었다. 그러나 세포내 효소 발현은 불용성의 inclusion body로 존재하므로 단백질 변성제인 urea와 재생제인 ${\beta}$-cyclodextrin을 사용하여 순수분리가 가능하였다. 이러한 방법은 LUGT의 당단백질의 특성연구는 물론 이를 이용한 제주 감귤의 고부가가치를 위한 기초연구에 많은 도움을 줄 것으로 판단된다.

• The Plant Pathology Journal
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• 제24권2호
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• pp.152-158
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• 2008

A peculiar virus-like disease of tomato showing yellow mosaic and necrotic spots on leaves and necrosis on veins, petioles and stems was observed at the Tomato Experimental Station (TES), Buyeo, Chungcheongnamdo, Korea. The disease incidence at TES fields ranged from 21 to 35% infecting different tomato cultivars. For this reason, to identify the virus infecting tomato and to characterize the virus based on biology, serology, cytology and at molecular level. Here, leaf samples were randomly collected from different infected tomato cultivars at TES fields and greenhouses and tested by ELISA using Pepper mottle virus (PePMoV) and Tomato mosaic virus (ToMV) antisera. Infected saps were mechanically inoculated in different host plants to test for pathogenicity, symptomatology and host ranges. Infected tissues and ultrathin sections were examined by electron microscopy. Finally, putative coat protein and 3'-untranslated region (CP/3'-UTR) fragment was amplified and cloned for sequence determination and analyzed its genetic relationship to existing PepMoV and PVY sequences at the Genbank. Results showed 69% of the samples were positive with PepMoV, 13% with ToMV and 19 % were doubly infected with PepMoV and ToMV. Symptoms greatly varied from different host plants inoculated with tomato leaf sap infected with PepMoV alone and discussed in detailed in this paper. Electron microscopy from infected tissues showed filamentous particles of 720-750nm in length, a typical morphology and size of PepMoV. In addition, cylindrical inclusion bodies, pinwheels, scrolls and laminates with masses of fibrillar inclusions were also found in ultrathin sections. Alignment of the sequences of the CP/3'-UTR revealed >96% sequence identity with PepMoV and only <61% with PVY. Taken together, all these evidences presented clearly indicated that the causal agent infecting tomato at TES was PepMoV and we designated this PepMoV infecting tomato as Tom-sd2 strain in this study.

• Applied Microscopy
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• 제29권3호
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• pp.291-301
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• 1999

초기발생중인 태령 9주부터 20주의 사람 태아의 허파 7예에서 과립허파꽈리세포의 분화과정과 미세구조의 특징을 밝히고자 투과전자현미경으로 관찰한 결과는 다음과 같다. 1. 발생 9주와 12주에서 기관지 나무의 상피의 형태로는 과립허파꽈리세포의 분화를 확인할 수 없었지만 발생이 진행되면서 15주 후부터 허파꽈리를 형성할 부위의 상피는 점차 거짓중층상피에서 단순입방상피로 분화하였다. 2. 발생 9주에서 처음으로 뭇층판소체가 관찰되어 과립허파꽈리세포의 분화를 확인할 수 있었다. 이외에도 발생 $9\sim15$주 동안에 이 세포에 특징적인 세포질포함체, 과립상포함체, 뭇소포포함체 그리고 진한포함체 등의 세포내 포함물을 관찰할 수 있었다. 3. 발생 19, 20주에서 뭇층판소체는 수와 크기가 급격하게 증가하였지만 다른 세포내 포함물은 감소되어 있었다. 요약하면 사람 태아의 허파에서 발생 초기단계에 뭇층판소체를 가진 허파꽈리세포(또는 전구세포)가 관찰되었으며, 이외에도 특징적인 다양한 세포내 포함물을 가진 세포들이 관찰되었다. 그러므로 과립허파꽈리세포는 발생 9주 또는 그 이전부터 분화한다고 할 수 있다.

• Bulletin of the Korean Chemical Society
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• 제22권12호
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• pp.1361-1365
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• 2001

Recombinant immunotoxins are hybrid cytotoxic proteins designed to selectively kill cancer cells. A divalent immunotoxins, [B3(FabH1)-PE38]2, was constructed by recombining Fab domain of B3 antibody as a cell-targeting domain and Pseudo monas exotoxin A (PE) as a cytotoxic domain. Monoclonal antibody, B3, is the murine antibody (IgG1k) directed against Lewis Y-related carbohydrate antigens, which are abundant on the surface of many carcinomas. Fab fragment of this antibody was used in this study with the modified hinge sequence where last two cysteines out of three were mutated to serine. PE is a 66 kDa bacterial toxin that kills eukaryotic cells by inhibiting protein synthesis with ADP ribosylation of ribosomal elongation factor 2 (EF2). Fc region of B3 antibody was substituted with the truncated form of PE (38 kDa, PE38) on DNA level. [B3(FabH1)-PE38]2 was formed by disulfide bond between cysteines in the modified hinge region of B3(FabH1)-PE38. Each polypeptide for recombinant immunotoxins was overexpressed in Escherichia coli and collected as inclusion bodies. Each inclusion body was solubilized and refolded, and cytotoxic effects were measured. Divalent immunotoxins, [B3(FabH1)-PE38]2, had ID50 values of about 10 ng/mL on A431 cell lines and about 4 ng/mL on CRL1739 cell lines. Control immunotoxins, B3(scFv)-PE40, had ID50 values of about 28 ng/mL on A431 cell lines and about 41 ng/mL on CRL1739 cell lines. Divalent immunotoxins, [B3(FabH1)-PE38]2, had higher cytotoxic effects than B3(scFv)-PE40 control immunotoxins.

• Biomolecules & Therapeutics
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• 제29권1호
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• pp.83-89
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• 2021

Multiple system atrophy (MSA) is a neurodegenerative disease characterized by presence of α-synuclein-positive inclusions in the cytoplasm of oligodendrocytes. These glial cytoplasmic inclusions (GCIs) are considered an integral part of the pathogenesis of MSA, leading to demyelination and neuronal demise. What is most puzzling in the research fields of GCIs is the origin of α-synuclein aggregates in GCIs, since adult oligodendrocytes do not express high levels of α-synuclein. The most recent leading hypothesis is that GCIs form via transfer and accumulation of α-synuclein from neurons to oligodendrocytes. However, studies regarding this subject are limited due to the absence of proper human cell models, to demonstrate the entry and accumulation of neuronal α-synuclein in human oligodendrocytes. Here, we generated mature human oligodendrocytes that can take up neuronderived α-synuclein and form GCI-like inclusions. Mature human oligodendrocytes are derived from neural stem cells via "oligosphere" formation and then into oligodendrocytes, treating the cells with the proper differentiation factors at each step. In the final cell preparations, oligodendrocytes consist of the majority population, while some astrocytes and unidentified stem cell-like cells were present as well. When these cells were exposed to α-synuclein proteins secreted from neuron-like human neuroblastoma cells, oligodendrocytes developed perinuclear inclusion bodies with α-synuclein immunoreactivity, resembling GCIs, while the stem cell-like cells showed α-synuclein-positive, scattered puncta in the cytoplasm. In conclusion, we have established a human oligodendrocyte model for the study of GCI formation, and the characterization and use of this model might pave the way for understanding the pathogenesis of MSA.

• 한국세라믹학회지
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• 제26권3호
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• pp.305-314
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• 1989

Effect of pH variation in starting solution for the making of hydroxyapatite powder was studied in relation to the sinterability of the powder and their mechanical properties of the sintered hydroxyapatite ceramics. The sinterability of hydroxyapatite powder prepared at different pH was found to be improved with increase in pH value of the starting solutions. Thus the powders prepared from the higher pH solutions including 10.5, 11.0 and 11.5 could be well densified almost upto theoretical density by firing for 1 hr at 1,00$0^{\circ}C$. But the powder based on pH 10 exhibited less sinterability even being fired at much higher temperature of 1,10$0^{\circ}C$, it gave only 90-95% of theoretical density. On the other hand the powder prepared on the lowest pH value 9.5 could not be well densified and it could obtain only 78% of theoretical density even by firing at 1,30$0^{\circ}C$ for 1hr. It was found that prismatic crystals of whitlockite were always included in the sintered bodies based on the lower pH values as a minority crystalline phase together with the major crystalline phase of hydroxyapatite and its inclusion might impair the sinterability of powder. However in the case of the higher pH, the powder contained only hydroxyapatite as a crystalline phase on sintering without any minorities. The sphere shape of crystals might help effectively the densification of the bodies. The best mechanical properties could be obtained from the body of pH 11 sintered at 1,10$0^{\circ}C$, which gave 99.5% of theoretical density, 662Kg/$\textrm{mm}^2$ of vickers hardness and 1,352Kg/$\textrm{cm}^2$ of diameteral compression strength.

• Applied Microscopy
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• 제39권2호
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• pp.73-80
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• 2009

다양한 색소체 내에 형성되는 결정체와 미세소관의 분포 및 발달양상을 식물이 수행하는 광합성 양식과 연계하여 꽃피는식물 종들에서 밝혀진 결과에 의하면, 색소체 결정체는 대개 격자 구조를 이루며 기질 또는 티라코이드 내에 형성되나, 미세소관은 비교적 규칙적인 형태로 기질에만 발달한다고 알려져 있다. 격자구조는 막으로 둘러싸이거나 막과는 무관하게 발달하며, 계통학적인 유연관계를 형성하지 않고 C-3 또는 C-4 또는 CAM 광합성을 수행하는 26개의 식물과, 약 56종에서 독립적으로 나타난다는 사실이 조사되었다. 색소체 결정체 및 미세소관 형성에 대한 지속적인 연구는 이들의 구조와 기능에 대하여 새로운 정보를 제공하나, 결정체에 대한 3차원적 입체구조 연구와 미세소관에 대한 분자생물학적인 실험법들이 요구되고 있는 실정이다. 특히, HVEM 고압전자현미경 및 tomography에 의한 연속절편 연구는 결정체의 3-D 입체구조 구현이 가능하여 심도 있는 구조정보를 제공하는 것으로 알려져 있다. 극히 일부의 식물에서만 보고되어 있는 색소체 내 미세소관에 대한 연구에 관해서는 먼저 색소체 기질에서 이들의 형성 시점을 알아내어 기질에서의 식별 및 분리 연구 등이 가능하게 돼야함이 강조되고 있다. 본 논문에서는 꽃피는식물 종들의 여러 색소체 유형에서 보고된 결정체와 미세소관을 조사하여 색소체 내에서 이들의 기능을 광합성과 연계하여 종합적으로 논의하였다.

• 자원환경지질
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• 제9권1호
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• pp.27-43
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• 1976

The flourite in Hwacheon, Hwanggangri and Keumsan district are major fluorite producing areas in Korea. The fluorite deposits of Hwacheon district are wholly fissure filling hydrothermal veins embedded in Precambrian gneiss and schists and Jurassic granites. Also some fluorite deposits are emplaced in felsite whose age is unknown. Emplacement of most fluorite veins of the district are controlled by EW fracture system. Fluorites are generally accompanied to chalcedonic quartz and also kaolinite, montmorillonite, dickite and calcite in parts. Vertical and lateral mineral zonings are not distinct. The fluorite deposits in the Hwanggangri district are wholly embedded in limestone and other calcareous sediments of Paleozoic Yeongweol Group. Most of the fluorite deposits belong to one of two categories which are steeply. dipping veins and gently dipping replacement deposits adjacent to Late Cretaceous(83-90mys) granite bodies. The strikes of fluorite veins of Hwanggangri district mostly occupy the fractures of $N30^{\circ}-40^{\circ}E$ and $N30^{\circ}-40^{\circ}W$ system. Fluorites are accompanied to calcite, milky quartz, chalcedonic quartz, and also montmorillonite, kaolinite in parts. But in some deposits, scheelite, various sulfide minerals and barite are accompanied. Emplacement of fluorite deposits are largely controlled by lithology and structures of this district. In some deposits fluorite veins gradate to scheelite veins and also telescoping of the mineral zones are found in this district. In the Keumsan district, fissure-filled fluorite veins and replacement deposits are mostly emplaced in limestone of Paleozoic Yeongweol Group, late Cretaceous quartz-porphyry, granite and sandstone. Some deposits are emplaced in Precambrian metasediments. Mineralogy and other characteristics of the deposits in this district is similar to those of Hwanggangri district. Fluid inclusion studies reveal the difference of salinities, $CO_2$ contents of ore fluid and temperatures during fluorite mineral deposition in the these districts. In Hwacheon district, ore-fluids were comparatively dilute brine and low $CO_2$ content. Filling temperatures ranges $104^{\circ}C$ to $170^{\circ}C$. In the Chuncheonshinpo mine, most deeply exploited one in this district, salinitles range 0.5-2. 2wt. % NaCl and filling temperatures range from $116^{\circ}C$ to $143^{\circ}C$. In the Hwanggangri district, ore fluids were complex and filling temperature ranges very widly. In the contact metasomatic fluorite deposits, ore fluid were NaCl rich brines with moderate $CO_2$ content and filling temperatures range from $285^{\circ}C$ to above $360^{\circ}C$. Fluids inclusions in tungsten and sulfide minerals bearing fluorite veins show high $CO_2$ content up to 31wt. %. Filling temperature ranges from $101^{\circ}C$ to $310^{\circ}C$. Fluids inclusions In mainly fluorite bearing veins were more dilute brine and low $CO_2$ contents. Filling temperatures range from $95^{\circ}C$ to $312^{\circ}C$. Filling temperature of fluid inclusions of Keumsan district are between $95^{\circ}C$ and $237^{\circ}C$. Data gathered from geologic, mineralogic and fluid inclusion studies reveal that fluorite mineralization in H wacheon district proceeded at low temperature with dilute brine and low $CO_2$ content. In Hwangganri district, fluorite mineralization proceeded by several pulse of chemically distinct ore fluids and formed the mineralogically different type of deposits around cooling granite pluton which emplaced comparatively shallow depth.

• Journal of Microbiology and Biotechnology
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• 제6권2호
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• pp.79-85
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• 1996

By using a T7 expression system, a large amount of Bacillus stearothermophilus endo-xylanase A (XynA) could be produced in Escherichia coli cells. The overproduced enzyme formed inclusion bodies, and so the protein could be more easily purified to homogeneity. The molecular weight of the purified enzyme was estimated to be 22 kDa by SDS-polyacrylamide gel electrophoresis and 43 kDa by Sephacryl S-200 gel filtration, suggesting that the native enzyme was a homodimer. The pI value was determined to be 8.4. The Michaelis constants for birchwood xylan and oat spelts xylan were calculated to be 3.83 mg/ml and 5.03 mg/ml, respectively, and the $V_{max}$ max/ values for both xylans were 2.86 $\mu mole$/min. The purified enzyme was most active at $55^{\circ}C$ and pH 8.0, and stable up to $60^{\circ}C$ and in the near neutral pH range. From the zymogram, Bacillus stearothermophilus was found to have at least three xylanases and the purified one was the smallest among them.

• Asian-Australasian Journal of Animal Sciences
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• 제27권4호
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• pp.561-566
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• 2014

The complete coding sequence of Wild Argali ISG15 cDNA was generated by rapid amplification of cDNA ends. The ISG15 cDNA was 642 bp with an open reading frame of 474 bp, which encoded a 17.47 kDa protein composed of 157 amino acids. Its amino acid sequence shared 97.9%, 80.8%, 91.4%, 94.3%, 78.3% identity with those of ISG15cDNA from Ovis aries (accession no. NM001009735.1), Capra hircus (accession no. HQ329186.1), Bos taurus (accession no. BC102318.1), Bubalus bubalis (accession no. HM543269.1), and Sus scrofa (accession no. EU647216.1), respectively. The entire coding sequence was inserted into the pET-28a vector and expressed in E. coli. The recombinant protein corresponded to the expected molecular mass of 25 kDa as judged by SDS-PAGE, and it was detected in the bacterial inclusion bodies. The expressed protein could be purified by $Ni^{2+}$ chelate affinity chromatography and the results from the lymphocyte proliferation test showed that the product could stimulate lymphocyte proliferation very well (p<0.05), which further confirmed its biological activity.