• Bulletin of the Korean Chemical Society
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• 제13권2호
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• pp.119-122
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• 1992

The affinity chromatographic technique was applied to the isolation of Thromboxane Synthase, with a variety of imidazolyl alkanoic acids coupled Sepharose 2B including a gel (G in Table 4) which has one free COOH group in the bound affinity ligand. The effect of ligand structure on the "affinity" and "selectivity" for thromboxane synthase isolation is described.

• 한국정보과학회논문지:시스템및이론
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• 제35권4호
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• pp.166-171
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• 2008

전체문서(Corpus)에서의 두 단어 간 연결 상태를 파악하여 앞 단어 다음에 오는 단어의 빈도수를 기반으로 여러 형태의 그룹을 분류하여 단어 간 다양성과 긴밀성을 살펴보았다. 기존의 연구에서 Zipf's Power Law는 Chinese Restaurant Process로 설명되었고 Scale Free Network에서는 edged의 수에 따른 노드의 profile을 조사하여 hub들을 찾는 연구가 수행되었다. 본 연구에서는 단어 간 연결의 유일성과 다양성을 조사하여 Zipf's Power Law와 hub profile을 동시에 살펴보았다. 데이타 분석 결과 단어 간 연결의 긴밀성과 다양성 사이에서 대칭성으로 함축되는 유의한 결과를 얻었으며 이는 소위 'exploitation'과 'exploration'의 관점에서 설명될 수 있다. 또한 분석 자료인 TIPSTER에서 관찰된 약간의 대칭성 깨짐(symmetry breaking)에 대해서도 논한다.

• 약학회지
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• 제47권3호
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• pp.176-179
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• 2003

A library of unlimited number of novel lectins with diverse specificities has been previously generated by randomly mutating the carbohydrate-recognition domain of Maackia amurensis hemagglutinin (MAH). To establish the experimental environment capable of selecting high affinity mutant lectins in E. coli, phage display system was adapted. Carbohydrate binding capacity of two phagemid vectors, pComb3 and pComb8 displaying wild-type MAH lectin was assessed. Specific bindings of pComb3 and pComb8 phages expressing w.t. MAH to affinity-purified polyclonal anti-MAH antibody and to glycophorin was demonstrated. Both phages also showed strong hemagglutinating activity to intact but not sialidase-treated human erythrocytes, which is consistent to the specificity of native MAH. Taken together, two different phage display vectors successfully allowed the expression of active MAH as a fusion protein on the surface of bacteriophage, which will lead to preparation of unique plant lectins with high affinity toward a variety of carbohydrate chains.

• BMB Reports
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• 제28권4호
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• pp.281-289
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• 1995

Homogeneous human deoxycytidine kinase was purified in one step from a variety of spontaneous human leukemic cells (T-ALL, B-ALL, B-CLL, AML, CML), and from cultured T-lymphoblast cells (MOLT-4) using the newly developed affinity medium, $dCp_4$-Sepharose. Starting with an ammonium sulfate fraction, purification was achieved in one step with the kinase being eluted from a column by the end product inhibitor, dCTP. The purified deoxycytidine kinase from T-ALL cells phosphorylated deoxyadenosine and deoxyguanosine, as well as deoxycytidine. The enzyme purified from T-ALL and B-CLL cells yielded one major band with a molecular weight of 52 kDa determined by SDS-polyacrylamide gel electrophoresis. AML and CML cells yielded one 52 kDa band and an extra band of 30 kDa molecular weight. On the other hand, B-ALL and MOLT-4 cells showed a low molecular weight band of 30 kDa only. However, the electrophoretic mobilities of enzymatic activity in 12% non-denaturing gels were identical for the dCyd kinase from all different kinds of leukemic cell lines, except that the B-ALL, B-CLL, and MOLT-4 cell preparations had an extra minor peak, all at the same position. dAdo and dCyd phosphorylating activities comigrated indicating that these activities are all associated with the same protein. Two new methods, a disk implantation method and a nitrocellulose powder method were used with a small amount of enzyme protein to raise polyclonal antibodies against dCyd kinase purified from T-ALL cells.

• 한국미생물·생명공학회지
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• 제21권4호
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• pp.336-341
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• 1993

In metal-affinify aqueous two-phase systems, protein partitioning is affected by a variety of parameters such as pH, the number of surface-accessible histidines, and the amount and partition coefficient of metallated polythylene glyco(PEG) ligand. To enhance partitioning of proteins with surface-accessible histidines, we have synthesized and used a (Cu(II)-ininodiacetic acid)$_2$-PEG20,000($Cu(II)_2IDA_2$-PEG20,000) as well as Cu(II)IDA-PEG5,000 as an affinity ligand. The partition coefficient of $Cu(II)_2-IDA_2$-PEG20,000 in a PEG5,000/dextran two-phase system was 30.1, which corresponded to a 3.8-fold increase over that of Cu(II)IDA-PEG5,000. The partitioning experiments were performed on four proteins, horse cytochrome c, S. cerevisiae cytochrome c, horse myoglobin, and sheep myoglobin. Partitioning of proteins which convey surface-accessible histidines was enhanced dramatically by the addition of $Cu(II)_2IDA_2$-PEG20,000 ligand. These results demonstrate that enhanced partitioning of metal-binding proteins in an aqueous two -phase system can by achieved by using an appropriate metallated PEG ligand.

• EDISON SW 활용 경진대회 논문집
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• 제5회(2016년)
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• pp.62-66
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• 2016

Tumor suppressor protein p53 loses its function upon binding with the HDM2 protein, and inhibiting the p53-HDM2 interaction is critical to suppress tumor cell growth. Recently, the cyclized helix-loop-helix peptide (cHLH) mimicking the ${\alpha}-helix$ part of the p53 protein has been designed and found to exhibit high binding affinity with HDM2. Here, we report the structural and thermodynamic characteristics of the bound complex of the cHLH peptide with the HDM2 protein. We performed molecular dynamics simulations to investigate the structural features of the cHLH peptide as well as its complex with the HDM2. The binding free energy calculation based on the integral equation theory was also executed to quantify the binding affinity for the cHLH/HDM2 complex and to understand the factors contributing to the binding affinity. We found a variety of factors for the helix stability of the cHLH peptide as well as in the complexation with the HDM2, which may provide an insight into the development of anti-cancer drug designs.

• BMB Reports
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• 제41권3호
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• pp.177-183
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• 2008

Ubiquitin is an essential, highly-conserved small regulatory protein in eukaryotic cells. It covalently modifies a wide variety of targeted proteins in the forms of monomer and polymers, altering the conformation and binding properties of the proteins and thus regulating proteasomal delivery, protein activities and localization. Mass spectrometry has emerged as an indispensable tool for in-depth characterization of protein ubiquitination. Ubiquitinated proteins in cell lysates are usually enriched by affinity chromatography and subsequently analyzed by mass spectrometry for identification and quantification. Ubiquitin-conjugated amino acid residues can be determined by unique mass shift caused by the modification. Moreover, the complex structure of polyubiquitin chains on substrates can be dissected by bottom-up and middle-down mass spectrometric approaches, revealing potential novel functions of polyubiquitin linkages. Here I review the advances and caveats of these strategies, emphasizing caution in the validation of ubiquitinated proteins and in the interpretation of raw data.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2007년도 한국컴퓨터종합학술대회논문집 Vol.34 No.1 (A)
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• pp.31-32
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• 2007

• 분석과학
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• 제8권4호
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• pp.535-538
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• 1995

This study employs the variety of mixtures of XAD resin and active carbons as concentration base for solid phase extraction (SPE) which has been widely used to preconcentrate and purify phenol and chlorophenols in determination of environmental water samples. In this study, we employed variety of mixtures of copolymer based XAD-4 resin with active carbons. This cartridges shows advantages of both materials, such as better affinity to phenol by active carbon and better mechanical stabilities from XAD resin. The better enrichment factor, pretreatment time, recoveries and limit of detection (LOD) were achieved by the attempts to pack precolumns with both meterials for preconcentration.

• 한국건설관리학회논문집
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• 제14권3호
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• pp.157-166
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• 2013

BTL(Build-Transfer-Lease) 사업의 목적은 종래 BTO(Build-Transfer-Operate) 방식과는 달리 학교, 사회복지시설 등 최종 이용자로부터 이용료를 부과할 수 없는 공공시설에 대하여 민간자금을 유치함으로써 정부의 재정부족을 해결하고 사회기반시설의 조기 확충을 위한 방안으로 도입되었다. 하지만 BTL 사업은 그 진행과정에서 다양한 문제점을 발생시키고 있으며, 이를 개선할 수 있는 실질적인 접근이 요구된다. 이에 본 연구에서는 국내의 BTL사업의 문제점에 대한 연구 자료와 국내보다 앞서 BTL 사업을 활용하고 있는 국외 자료를 분석하여 문제 영역을 도출하였다. 그리고 이를 체계적으로 관리하기 위해 친화도 기법, 매트릭스 비교분석, AHP 기법을 활용하여 중요도를 분석하였다. 분석된 결과는 BTL 사업의 실질적 문제 영역 및 중요도 제시를 통하여 관리 기준을 제공할 것으로 기대된다.