• 분석과학
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• 제11권4호
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• pp.292-296
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• 1998

헤테로 고리 화합물인 isoquinoline과 외부치환체로서 $COOCH_3$, CN 및 $CH_3$ 작용기들이 치환된 화합물들의 혼합물을 정상 및 역상법으로 분리 한 결과, 이동상의 종류에 따라 용리순서에 용매화 효과가 나타났다. 또한, 헤테로 고리 화합물 내부의 방향족성이 없는 2-methylindoline과 방향족성이 있는 2-methylindole, 그리고 헤테로 원자가 질소와 산소인 benzoxazole과 질소와 황인 benzothiazole의 머무름거동은 정상 액체 크로마토그래피의 경우 시료 분자와 충진제의 흡착 표면과의 흡착력으로 설명할 수 있었고, 역상 액체 크로마토그래피의 경우는 시료와 정지상과의 소수성 상호작용 등으로 설명할 수 있었다.

• 한국수소및신에너지학회논문집
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• 제27권6호
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• pp.660-669
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• 2016

A fluorinated-sulfonated, hydrophobic-hydrophilic copolymer was planed subsequently synthesized using typical nucleophilic substitution polycondensation reaction. A novel AB and ABA (or BAB) block copolymers were synthesized using sBCPSBP (sulfonated 4,4'-bis[4-chlorophenyl)sulfonyl]-1,1'-biphenyl), DHN (1,5-dihydroxynaphthalene), DFBP (decafluorobiphenyl) and HFIP (4,4'-hexafluoroisopropylidenediphenol). All block copolymers were easily cast and made into clear films. The structure and synthesized copolymers and corresponding membranes were analyzed using GPC (gel permeation chromatography), $^1H$-NMR ($^1H$ nuclear magnetic resonance) and FT-IR (Fourier transform infrared). TGA (Thermogravimetric analysis) and DSC (differential scanning calorimetry) analysis showed that the prepared membranes were thermally stable, so that elevated temperature fuel cell operation would be possible. Hydrophobic/hydrophilic phase separation and clear ionic aggregate block morpology was confirmed in both triblock and diblock copolymer in AFM (atomic force microscopy), which may be highly related to their proton transport ability. A sulfonated BAB triblock copolymer membrane with an ion-exchange capacity (IEC) of 0.6 meq/g has a maximum ion conductivity of 40.3 mS/cm at $90^{\circ}C$ and 100% relative humidity.

• 고문화
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• 66호
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• pp.87-112
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• 2005

Stain removal on ivory has been, for a long time, considered an undesirable treatment in conservation field because ivory is hygroscopic and anisotropic, having different physical properties in different directions. Cyclododecane, which sublimes at room temperature, has been investigated for its use in conservation field since 1995, as a reversible temporary consolidant, sealing agent or coating, water repellent, and barrier layer. This research aims to remove stains on ivory, temporarily protecting the none-stained area or painted area from methanol, acetone or the aqueous cleaning system using cyclododecane as a hydrophobic sealing agent. This research also aims to obtain information regarding whether cyclododecane can be safely and effectively used on archaeological wet ivory. Melted cyclododecane and saturated solutions of cyclododecane in mineral spirits, and hexanes were applied to ivory samples. Application methods, working properties of cyclododecane on ivory, and effect of cyclododecane coating on moisture content of wet ivory were evaluated. The sealing layer formed by molten cyclododecane or by saturated cyclododecane solution in hexane or saturated cyclododecane solution in mineral spirits did not form a secure contact with the surface of the highly polished ivory. The sealing formed with two different layers, in which saturated cyclododecane solution in hexane was applied initially and then molten cyclododecane was applied over the first layer, was found to securely protect the painted area. When the wet samples were kept in 100% RH environments for a month, active mold growths were observed except in the samples sealed with molten cyclododecane. In conclusion, cyclododecane was an efficient hydrophobic sealing agent to protect painting area while cleaning stains on ivory. It also prevented mold growing on wet ivory and wet bone. Evenness of cyclododecane film on ivory will be determined in UV light. Analytical techniques will include visual observation, polarized light microscopy, Scanning Electron Microscope, and Gas Chromatography.

• BMB Reports
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• 제40권2호
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• pp.232-238
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• 2007

The p13 gene is uniquely present in Group II nucleopolyhedroviruses (NPVs) and some granuloviruses, but not in Group I NPVs. p13 gene was first described by our laboratory in Leucania separatamultiple nuclear polyhedrosis virus (Ls-p13) in 1995. However, the functions of Ls-P13 and of its homologues are unknown. When Ls-p13 was inserted into Autographa californica nucleopolyhedrovirus, a Group I NPV, polyhedra yield was inhibited. However, this inhibition was prevented when the leucine zipper-like domain of Ls-p13 was mutated. To determine the cause of this marked difference between Ls-P13 and leucine zipper mutated Ls-P13 (Ls-P13mL), oligomerization and secondary structure analyses were performed. High performance liquid chromatography and yeast two-hybrid assays indicated that neither Ls-P13 nor Ls-P13mL could form oligomers. Informatics and circular dichroism spectropolarimetry results further indicated marked secondary structural differences between Ls-P13 and Ls-P13mL. The LZLD of Ls-P13 has two extended heptad repeat units which form a hydrophobic surface, but it is short of a third hydrophobic heptad repeat unit for oligomerization. However, the mutated LZLD of Ls-P13mL lacks the above hydrophobic surface, and its secondary structure is markedly different. This difference in its secondary structure may explain why Ls-P13mL is unable to inhibit polyhedra yield.

• Bulletin of the Korean Chemical Society
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• 제34권2호
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• pp.558-564
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• 2013

A simple and effective method is introduced to synthesize a series of polystyrene-b-poly(oligo(ethylene oxide) monomethyl ether methacrylate)-b-polystyrene (PSt-b-POEOMA-b-PSt) triblock copolymers. The structures of PSt-b-POEOMA-b-PSt copolymers were characterized by Fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance ($^1H$ NMR) spectroscopy. The molecular weight and molecular weight distribution of the copolymer were measured by gel permeation chromatography (GPC). Furthermore, the self-assembling and drug-loaded behaviours of three different ratios of PSt-b-POEOMA-b-PSt were studied. These copolymers could readily self-assemble into micelles in aqueous solution. The vitamin E-loaded copolymer micelles were produced by the dialysis method. The micelle size and core-shell structure of the block copolymer micelles and the drug-loaded micelles were confirmed by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The thermal properties of the copolymer micelles before and after drug-loaded were investigated by different scanning calorimetry (DSC). The results show that the micelle size is slightly increased with increasing the content of hydrophobic segments and the micelles are still core-shell spherical structures after drug-loaded. Moreover, the glass transition temperature (Tg) of polystyrene is reduced after the drug loaded. The drug loading content (DLC) of the copolymer micelles is 70%-80% by ultraviolet (UV) photolithography analysis. These properties indicate the micelles self-assembled from PSt-b-POEOMA-b-PSt copolymers would have potential as carriers for the encapsulation of hydrophobic drugs.

• 생명과학회지
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• 제30권2호
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• pp.137-146
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• 2020

식물에서 Ca²⁺는 세포의 중요한 2차 신호 전달 분자 중 하나이다. Ca²⁺ 및 인산화 효소의 센서 단백질인 칼슘-의존성 단백질 카이네즈(CDPKs)는 식물 세포에서 가장 풍부한 세린/트레오닌 키나아제이다. 이들은 다양한 자극에 대한 신호를 변환하여 식물에서 특정 반응을 일으킨다. 벼에는 31개의 CDPK 유전자 족이 확인되었다. 그들은 주로 식물의 생장과 발달에 관여하며 다양한 스트레스 조건에 반응하여 기능을 하는 것으로 알려져 있다. 그러나 CDPK 단백질의 생화학적 특성에 대해서는 알려진 바가 별로 없다. 이 연구에서는 벼의 CDPK 중 하나인 OsCPK11을 부분 정제하여 그 생화학적 특성을 조사하고자 하였다. 벼 유식물에서 3단계 칼럼 크로마토그래피 과정을 거쳐 부분 정제된 OsCPK11을 얻었다. 정제 과정에는 DEAE를 사용한 음이온 교환 크로마토그래피, Phenyl-Sepharose를 사용한 소수성 상호작용 크로마토그래피 및 Sephacryl-200HR를 사용한 겔 여과 크로마토그래피를 포함하였다. 부분 정제된 OsCPK11은 분자량이 54kDa이며 소수성 수지와 강한 소수성 상호작용을 보였다. 부분 정제된 OsCPK11으로 in vitro kinase assay를 실시한 결과, OsCPK11은 Ca²⁺-의존성 자가인산화 활성을 가짐을 보여 주었다. OsCPK11은 histone III-S를 인산화 하였으며, 카이네즈 활성의 최적 pH는 7.5-8.0이었다. Native OsCPK11은 이전에 연구된 재조합 OsCPK11과 몇 가지 생화학적 특징을 공유하였는데, 둘 다 Ca²⁺-의존성 자가인산화 활성을 나타냈다. 또한, 둘 모두 카이네즈 활성을 위한 기질로서 histone III-S를 선호하였으며, Ca²⁺ 의존성을 보여 주었다.

• Journal of Microbiology and Biotechnology
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• 제15권2호
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• pp.395-402
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• 2005

Biologically active recombinant human follicle stimulating hormone (rhFSH) was produced in Chinese hamster ovary cells and purified by a series of chromatographic steps. The chromatographic steps included anion-exchange chromatography (DEAE Sepharose F/F, Q Sepharose F/F), hydrophobic interaction chromatography (Source 15 PHE), and hydroxyapatite chromatography (Macro-Prep ceramic hydroxyapatite type I). A distinctive step of the purification process developed was the use of ZnCl$_2$ for the removal of non-glycosylated or lowly-glycosylated FSH and impurities through co-precipitation with Zn$^{2+}$. Purified rhFSH was identified and characterized by several physicochemical and biological methods such as gel electrophoresis, high-performance liquid chromatography, amino acid analysis, carbohydrate analysis, and biological activity. The overall yield of the purification was ~$30\%$. The rhFSH preparation obtained showed high purity (>$99\%$) and high in vivo potency (>16,000 IU/mg). Carbohydrate analysis suggested that the purified rhFSH contained approximately $40\%$ (w/w) carbohydrate with di­or tri-antennary structure on average, which is somewhat more heavily sialylated than commercially available rhFSH. In conclusion, the results of these analyses established an identity of the purified rhFSH with natural FSH from human pituitary glands, and furthermore, the purified rhFSH preparation showed higher in vivo potency and was slightly more heavily sialylated than commercially available rhFSH.

• 한국식품영양과학회지
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• 제40권10호
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• pp.1447-1452
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• 2011

우리나라 버섯 생산량의 약 80%를 차지하는 느타리버섯(Pleurotus ostreatus)의 유통 중에 발생하는 갈변을 방지하기 위한 기초 조사로 갈변원인 효소인 polyphenol oxidase(PPO)를 분리 정제하여 그 특성을 조사하였다. 느타리버섯으로부터 3개의 PPO isoforms(PO-I, PO-II-1, PO-II-2)을 분리하였으며, gel-filteration을 이용한 분자량 확인 결과 PO-II-1은 void volume(70 kDa), PO-I과 PO-II-2는 include volume(6 kDa)에서 분리되는 것으로 보아 PO-II-1은 70 kDa 이상, PO-I과 PO-II-2는 6 kDa 이하인 것으로 확인되었다. 분리된 3개의 PPO isoform들을 partially denatured-PAGE 후, activity staining을 이용하여 분석한 결과, 비록 이들 PPO isoforms PO-II-1과 PO-II-2에 다수의 단백질들이 들어있기는 하지만 PPO 활성을 보이는 band가 하나로 나타남으로써 분리된 PPO isoform들이 실제 PPO 활성을 갖고 있는 단백질로 확인되었으며 다른 PPO isoform이 혼합되지 않은 단일 PPO isoform으로 분리되었음을 알 수 있다. Hydrophobic interaction chromatography에서 분리된 isoform PO를 이용하여 특성을 조사한 결과 최적 반응온도와 pH는 일반적인 다른 과채류와는 달리 $50{\sim}55^{\circ}C$, pH 5.5에서 높은 활성을 나타내었으며, 열 안정성 실험에 있어서는 $60^{\circ}C$에서 45분간 가열 처리 시 약 40%의 PPO activity가 남아있는 반면, $80^{\circ}C$에서 30분간 가열 처리 시 PPO가 완전히 불 활성화되었다. 그리고 chlorogenic acid와 pyrogallol에 대하여 높은 기질 특이성을 보였다.

• Journal of Microbiology and Biotechnology
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• 제16권7호
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• pp.1047-1052
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• 2006

A bile salt hydrolase (BSH) was purified from Lactobacillus plantarum CK 102 and its enzymatic properties were characterized. This enzyme was successfully purified using ion-exchange chromatography with Q-Excellose and hydrophobic interaction chromatography with Butyl-Excellose. The purified enzyme showed a single protein band of 37 kDa by SDS-polyacrylamide gel electrophoresis, which was similar to the molecular weight of known BSHs. The amino acid sequence of GLGLPGDLSSMSR, determined by MALDI-TOF, was identical to that of BSH of L. plantarum WCFS1. Although this BSH hydrolyzed all of the six major human bile salts, glycine-conjugated bile acid was the best substrate, based on its specificity and $K_{m}$ value. Among the various substrates, the purified enzyme maximally hydrolyzed glycocholate with apparent $K_{m}$ and $V_{max}$ values of 0.5 mM and 94 nmol/min/mg, respectively. The optimal pH of the enzyme ranged from 5.8 to 6.3. This enzyme was strongly inhibited by thiol enzyme inhibitors such as iodoacetate and periodic acid.

• Preventive Nutrition and Food Science
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• 제19권3호
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• pp.213-219
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• 2014

Bacillus pumilus 2.g isolated from gembus, an Indonesian fermented soybean cake, secretes several proteases that have strong fibrinolytic activities. A fibrinolytic enzyme with an apparent molecular weight of 20 kDa was purified from the culture supernatant of B. pumilus 2.g by sequential application of ammonium sulfate precipitation, ion-exchange chromatography, and hydrophobic chromatography. The partially purified enzyme was stable between pH 5 and pH 9 and temperature of less than $60^{\circ}C$. Fibrinolytic activity was increased by 5 mM $MgCl_2$ and 5 mM $CaCl_2$ but inhibited by 1 mM phenylmethylsulfonyl fluoride (PMSF), 1 mM sodium dodecyl sulfate (SDS), and 1 mM ethylenediaminetetraacetic acid (EDTA). The partially purified enzyme quickly degraded the ${\alpha}$ and ${\beta}$ chains of fibrinogen but was unable to degrade the ${\gamma}$ chain.