• Journal of the Korean Chemical Society
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• v.49 no.6
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• pp.537-545
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• 2005

• Parasites, Hosts and Diseases
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• v.36 no.2
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• pp.133-142
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• 1998

A 40 kDa cysteine protease was purified from the crude extract of adult worms of GMnnophalloines seoi by two consecutive steps: Sephacryl S-200 HR and DEAE- Sephacel chromatography. Enzyme activities were completely inhibited by cysteine protease inhibitors, L-lorans-epoxysuccinylleucylamido (4-guanidino) butane (E-64) and iodoacetic acid, strongly suggesting that the purified enzyme belongs to the cysteine family of proteases. The enzyme was maximally acive at pH 4.5 in 0.1 M of buffer, and its activity was greatly potentiated in the presence of 5 mM dithiothreitol. The protease degraded macromolecules with differential capabilities : it degraded extracellular matrix proteins, such as collagen and fibronectin, with a stronger activity against collagen than fibronectin . However, the enzyme digested hemoglobin and human immunoglobulins only slightly. leaving them nearly intact after an overnight reaction. Our results suggest that the cysteine protease of G. seoi adults is potentially significant in the nutrient uptake from the host intestine.

• The Korean Journal of Zoology
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• v.30 no.2
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• pp.167-176
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• 1987

배추흰나비의 전용기 혈림프에서 $\beta$-N-Acetylglucosaminidase를 DEAE-cellulose ion exchange 및 Sephadex G-200 column chromatography 법을 이용하여 정제하였다. 정제된 효소는 7% acrylamide gel 전기영동에서 단일 band를 나타내었으며, 당을 함유한 복합단백질이었다. 최적 pH는 5.0, 최적반응온도는 6$0^{\circ}C$이었으며, 각 온도에서 10분간 incubation한 열안정성에 있어서는 6$0^{\circ}C$까지 비교적 높은 활성을 나타내었지만 7$0^{\circ}C$ 이후에는 거의 활성을 나타내지 않았다. 또한 Hg$^2$+ 처리는 심한 효소활성의 저해 현상을 보였지만, Mn$^2$+, $Mg^2$+ 등은 활성의 증가를 나타내었으며, Km 값은 6.67$\times$10-$^3$M, pl 값은 5.8, 분자량은 4.1$\times$105 daltons 이었다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.11A
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• pp.1661-1671
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• 2000

본 고에서는 한국통신(Korea Telecom) IMT-2000 시험시스템(이하: Trial system 라고 함) 단말기용 전력증폭단으로 적용하기 위한 다단구동증폭기 및 전력증폭기를 GaAs MMIC로 설계 구현하는 기술을 제시하였다. 설계된 구동증폭기는 3단으로구성하여 RF(Radia Frequency) 송신신호(1955$\pm$70MHz)대역에서 2단 (중간단)의 이득 조정범위가 40 dB이상이 될 수 있도록 능동부품인 MESFET를 Cascade 형으로 구성하고 MESFET의 게이트(gate)에 조정전압을 인가하는 증폭기를 설계하여 GaAs MMIC화 1 침(크기4$\times$5 mm)으로 제작하였다. 아울러, 본 논문에서는 제시한 구동증폭기는 동작주파수 대역폭 범위기 3.5배이고 출력전력은 15dBmm 이며, 출력전력이득이 25~27dB이고 반사계수는 -15~20dB이며 이득평탄도 3dB(동작주파수 대역폭내)로써 Trial system용 단말기의 최종단인 전력증폭단의 출력단 특성을 효과적으로 나타내었다. 그리고, 전력 증폭기는 2개의 입력단에서 출력되는 신호를 분배하는 전력분배기와 병렬구조인 4개의 증폭단에서 출력되는 출력신호를 외부에서 접속하는 전력결합기를 접소하여 구성하였으며 RF(Radio Frequency) 주파수(1955 $\pm$70NHz)에서 대역폭을 4배로 설계하여 광대역인 대역폭을 구현하였고 출력전력은 570mW이며, 출력부가효율(PAE; Power Added Efficency)가 -15$\pm$20dB이고, 이득 평탄도(Gain flatness)는 동작주파수 대역내에서 0.5dB이며 입출력 전압정재파비(Input & Output VSWR)가 13이하인 고출력 전력증포기를 GaAs MMIC화 1칩 (크기; 3$\times$4mm)으로 제작하였다.의 다양성이나 편리성으로 변화하는 것이 국적을 바꾸는 것보다 어려운 시 대가 멀지 않은 미래에 도래할 것이다. 신세기 통신 과 SK 텔레콤에는 현재 1,300만명이 넘 는 고객이 있으며. 이들 고객은 어 이상 음성통화 중심의 이동전화 고객이 아니라 신세기 통신과 SK텔레콤이 함께 구축해 나갈 거대란 무선 네트워크 사회에서 정보화 시대를 살아 갈 회원들이다. '컨텐츠의 시대'가 개막되는 것이며, 신세기통신과 SK텔레콤은 선의의 경쟁 과 협력을 통해 이동인터넷 서비스의 컨텐츠를 개발해 나가게 될 것이다. 3배가 높았다. 효소 활성에 필수적인 물의 양에 따른 DIAION WA30의 라세미화 효율에 관하여 실험한 결과, 물의 양이 증가할수록 그 효율은 감소하였다. DIAION WA30을 라세미화 촉매로 사용하여 아이소옥탄 내에서 라세믹 나프록센 2,2,2-트리플로로에틸 씨오에스터의 효소적 DKR 반응을 수행해 보았다. 그 결과 DIAION WA30을 사용하지 않은 경우에 비해 반응 전환율과 생성물의 광학 순도는 급격히 향상되었다. 전통적 광학분할 반응의 최대 50%라는 전환율의 제한이 본 연구에서 찾은 DIAION WA30을 첨가함으로써 성공적으로 극복되었다. 또한 고체 염기촉매인 DIAION WA30의 사용은 라세미화 촉매의 회수 및 재사용이 가능하게 해준다.해준다.다. TN5 세포주를 0.2 L 규모 (1 L spinner flask)oJl에서 세포간의 응집현상 없이 부유배양에 적응,배양시킨 후 세포성장 시기에 따른 발현을 조사한 결과 1 MOI의 감염조건 하에서는 $0.6\times10^6$cell/mL의 early exponential시기의 세포밀도에서 72시간 배양하였을 대 최대 발현양을 나타내었다. 나타내었다. $\beta$4 integrin의 표현이 침투 능력을 높이는 역할을 하나 이때에는 laminin과 같은 리간드와의 특이

• Korean Journal of Microbiology
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• v.36 no.1
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• pp.20-25
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• 2000

One of endoglucanases(F-II-II) was purified from the culture filtrate of Trichoderma sp. C-4 through two step procedures including chromatography on Sephacryl S-200 and Sephacryl S-100. The molecular weight of the enzyme was determined to be about 26,000 by SDS-PAGE and the isoelectric point as 8.0 by analytical isoelectric focusing. The optimum temperature of the enzyme was $50^{\circ}C$ and the optimum pH was 5.0. No loss of activity was observed when the enzyme was preincubated at $50^{\circ}C$ for 24 hours. The specific activity of the enzyme toward carboxymethylcellulose (CMC) was estimated to be 776.2 U/mg. The internal amino acid sequence was analysed.

• Korean Chemical Engineering Research
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• v.61 no.4
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• pp.576-583
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• 2023

This study aimed to investigate the impact of enhancing the electrode conductivity and mitigating the production of hydrogen peroxide - a by-product arising from lactate oxidation - on the performance of lactate electrodes. The electrical conductivity of the electrode was improved by modifying the surface of carbon paper with single-walled carbon nanotubes. Catalase was introduced to effectively eliminate the hydrogen peroxide produced during the lactate oxidation reaction. The carbon paper electrode, with simultaneous immobilization of both lactate oxidase and catalase, yielded a current 1.7 times greater than the electrode where only lactate oxidase was immobilized. The electrode in which lactate oxidase and catalase were co-immobilized on the surface of carbon paper modified with single-walled carbon nanotubes, produced a current of 171 µA, which was more than twice as much current as the carbon paper with only lactate oxidase immobilized. The optimized electrode showed a linear response up to lactate concentration of 20 mM, confirming that it can be used as a sensor electrode.

• Microbiology and Biotechnology Letters
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• v.31 no.3
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• pp.284-291
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• 2003

Bacillus amyloliquefaciens K-42, which produces strongly a fibrinolytic enzyme, Was isolated from Ganjang, a traditional Korean soy sauce. The fibrinolytic enzyme was purified to homogeneity by ammonium sulfate fractionation, ion-exchange chromatography on DEAE-Sephadex A-50, gel chromatography on Sephadex G-100, and gel chromatography on Sephadex G-75 of the culture filtrate of Bacillus amyloliquefaciens K42. The purified enzyme showed the specific activity of 59.4 units per milligram, which was increased by 17.1 fold over the culture broth. And the molecular weight of purified fibrinolytic enzyme was confirmed to be about 45,000 Dalton by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The enzyme activity was relatively stable at pH 4.0-10.0 and the optimum pH was 8.0. The activity of the purified enzyme was increased by $Mg^{2+}$ , Cu$^{2+}$ but the enzyme was totally inhibited by $Ba^{2+}$ $Hg^{2+}$ In addition, the enzyme activity was potently inhibited by EDTA, EGTA and CDTA. It was concluded that the purified enzyme was a metalloprotease. And Km value was 2.03 mg/ml to fibrin.

• Proceeding of EDISON Challenge
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• 2015.03a
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• pp.177-183
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• 2015

$\text\tiny{D}$-Psicose 3-Epimerase (DPE)는 $\text\tiny{D}$-Fructose의 C3 Epimerase로써 $\text\tiny{D}$-Fructose를 $\text\tiny{D}$-Psicose로 전환해 주는 효소이다. $\text\tiny{D}$-Psicose는 설탕 대신 사용하는 감미료로 몸에 흡수되지 않아 칼로리가 없다고 알려져 있고 자연에서는 오로지 DPE에 의해서만 생산되는 희귀당이다. 이에 따라 DPE를 통한 $\text\tiny{D}$-Psicose 대량생산의 필요성이 대두되고 있는 등 이 분야에 대한 관심이 뜨거운 실정이다. 본 연구팀은 이 당과 관련된 작용기작 연구를 수행하기 위하여 아직 단백질 3차구조가 알려지지 않은 Clostridium hylemonae DPE (chDPE) 단백질의 3차 구조예측 연구를 수행 하였다. 우리는 HHsearch를 이용하여 agrobacterium tumefaciens의 DPE 외 2개의 구조를 호몰로지 모델링 연구를 위한 주형으로 선정하였다. 다음으로 PROMALS3D를 이용하여 주형들과 chDPE의 multiple sequence alignment를 수행하였고 이를 바탕으로 3차구조 예측 연구를 수행 하였다. 예측된 구조를 검증하기 위하여 ProSA와 Ramachandran plot분석을 이용하였고 Ramachandran plot에서 단백질의 94.8%에 해당하는 잔기들이 favoured regions에 위치하였다. ProSA에서는 Z-score값이 -9.3으로 X-선 결정학이나 핵자기 공명법으로 밝혀진 구조들에서 관측되는 범위 내에 위치하였다. 나아가 예측된 구조에 $\text\tiny{D}$-Psicose와 $\text\tiny{D}$-Fructose의 결합모드를 규명하기 위하여 도킹을 시도하였다. 이번 연구를 통하여 chDPE의 구조를 예측 할 수 있었고 이를 바탕으로 이 단백질의 기능을 이해하는데 도움을 줄 것으로 기대된다.

• Journal of Korean Society of Forest Science
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• v.56 no.1
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• pp.26-50
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• 1982

In order to obtain more detailed information concerning the degradation of lignin in the oxygen alkali pulping single stage isothermal delignification of pine wood meal (Pinus koraiensis S. et Z.) was studied in the oxygen alkali system at five temperature level ($110^{\circ}C$, $120^{\circ}C$, $130^{\circ}C$, $140^{\circ}C$, $150^{\circ}C$) for 60 min.. The rate constant, activation energy, oxygen and alkali consumption during the oxygen alkali delignification were determined by the kinetic method. The 2/5 of total lignin was eliminated at the start of the reaction. The delignification rate constant was about 3 times that of caustic soda pulping. The activation energy was about 1/3 lower than in caustic soda pulping. Like oxygen consumption, alkali consumption was also rapid early at the reaction and almost ceased after about 10 min.. The degradation reaction of lignin was strongly dependent upon the pH decrease of the cooking liquor by organic acid generated in pulping. The lignin in the oxygen alkali pulping degraded into lover molecular weight and had more hydrophillic properties. The methoxyl group decreased considerably at the first of oxygen alkali delignification, while the carbonyl, carboxyl and phenolic hydroxyl group increased rapidly.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.7
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• pp.881-888
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• 2007

For the use of skipjack tuna cooking drip (STC) as a source of functional seasoning, the STC was hydrolyzed with various commercial enzymes, such as Alcalase, Flavourzyme, Neutrase and Protamex, and its hydrolysate was also investigated on the food component characteristics. The hydrolysate incubated with Alcalase for 30 min (HA30) showed 56.8% for angiotensin I converting enzyme (ACE) inhibitory activity and 1.18 for antioxidative activity, which were high or similar compared to the other enzymatic hydrolysates. There were no differences in ACE inhibitory activity and antioxidative activity among HA30, two-step enzymatic hydrolysates, and ultrafilterates (molecular weight cut off, 10 kDa). The HA30 was very stable on the digestive enzymes, such as chymotrypsin, pepsin, trypsin according to the TCA (trichloroacetic acid) soluble index. The results suggested that skipjack tuna cooking drip could be used as a source for preparing functional seasoning sauce.