• Proceedings of the Membrane Society of Korea Conference
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• 1998.04a
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• pp.120-123
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• 1998

1. 서론 : 생물기술이 급속히 발전함에 따라 다양한 생물제품들(예, 단백질, 효소, 항생제 등)이 생산되고 있으나, 그 생산량은 극단적으로는 기질용액 1g당 10$^{-8}$g 정도로까지 낮아, 이를 고순도로 정제하기 위해서는 다단계의 공정이 필요하여 분리정제의 비용이 크다. 따라서 생물제품의 산업적 생산이 경제성을 갖기 위해서는 생물제품을 보다 경제적으로 분리정제할 수 있는 효율적인 공정개발이 필수적이다. (생략)

• YAKHAK HOEJI
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• v.35 no.6
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• pp.461-465
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• 1991

Silica-based gel filtration chromatography has been used to characterize molecular weight of proteins. However, the molecular weight measured by this method was distorted by protein-silica interactions like hydrophobic and electrostatic forces. Therefore, we characterized protein-silica interaction using two forms of phytochrome (124 kDa) having different hydrophobicity and surface charge. PH and ionic strength affected the retention time of phytochrome suggesting that electrostatic force is the major interaction between protein and silica surface.

• Journal of the Korean Chemical Society
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• v.63 no.5
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• pp.387-391
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• 2019

• Korean Journal of Food Science and Technology
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• v.43 no.5
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• pp.618-623
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• 2011

Escherichia coli O157:H7 has been considered as a significant food-borne pathogen since its role in causing hemorrhagic colitis and hemolytic uremic syndrome in humans was recognized. In this study, we developed an immunochromatography (ICG) assay for the detection of E. coli O157:H7. E. coli O157:H7 monoclonal antibody (EC MAb) and colloidal gold were conjugated and its specificity was determined by the ICG treated with EC MAb and antimouse IgG at test and control lines, respectively. The detection limit of the ICG was $1{\times}10^5$ CFU/mL, and no crossreactivity was observed to other E. coli strains and major food-borne pathogens. To determine the minimum enrichment time for the ICG, meats and sprouts were inoculated with $1{\times}10$ CFU/100 ${\mu}L$ of E. coli O157:H7. After enrichment time of 10 and 2 h for meats and sprouts, respectively, up to $1{\times}10$ CFU/100 ${\mu}L$ of E. coli O157:H7 could be detected by ICG.

• Analytical Science and Technology
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• v.12 no.5
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• pp.408-414
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• 1999

A selective and sensitive method for the derivatization of total homocysteine (Hcy) and the related compounds in plasma by gas chromatograph (GC)-electron capture detector (ECD) has been developed. To determine total homocysteine, cysteine (Cys), and methionine (Met) in human plasma using GC-ECD, analytes were reduced and converted into their N(O,S)-ethylearbonyl pentafluoropropyl (PFP) ester by derivatization with ethyl chloroformate and pentafluoropropyl alcohol (PFP-OH) in plasma. The best derivatizing agent N(O,S)-ethyl carbonyl PFP ester, was chosen by comparing the sensitivity of derivatized analysis in GC-ECD. The derivatized analytes in plasma were extracted by chloroform, and subsequently back-extracted with hexane and analyzed by GC-ECD. The calibration carves ($R^2$ > 0.990) were linear over the range $5-50{\mu}mol/L$ of Hcy and Met, $40-400{\mu}mol/L$ of Cys spiked in plasma. The detection limit observed by the established method was below $0.5{\mu}mol/L$. This method is highly sensitive and specific in the analysis of Hcy, Cys, and Met. Therefore, we suggest that this method is appropriate in the analysis of trace concentration of Hcy, Cys, and Met in biological fluids.

• Journal of the Korean Chemical Society
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• v.25 no.5
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• pp.306-310
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• 1981

Induced circular dichroism spectra of racemic cobalt(III) complexes for $[Co(en)_3]^{3+},\;[Co(tn_)3]^{3+},\;cis-[Co(NH_3)(en)_2]^{3+},\;[Co({\beta}-ala)(en)2_]^{2+},\;[Co(gly)(en)_2]^{2+}\;and\;[Co(acac)(en)_2]^{2+}$ were measured when they were dissolved in aqueous d-tartrate2- solution at room temperature. Only a single negative CD spectrum was observed for all the complexes above in visible region(400∼500nm). It was interpreted that these CD bands were attributed to the difference in interaction between ${\Lambda}$-and ${\Delta}$-enantiomers with d-tartrate$^{2-}$. Namely, when d-tartrate$^{2-}$ was added to ${\Lambda}$-enantiomer and ${\Delta}$-enantiomer, it caused ${\Lambda}$-enantiomer to change greatly and ${\Delta}$-enantiomer to change only slightly; combined the results proved induced circular dichroism. The enantiomer for which the eluent has a stronger affinity should be eluted faster in ion-exchange column chromatography. It is possible to predict the elution order of chromatography from the sign of the induced CD if stronger interaction of chiral anion with the complex leads to greater change in the natural CD spectrum of the complex. The elution order was in complete agreement with the prediction from the sign of the induced CD spectrum for all the measured complexes.

• Korean Chemical Engineering Research
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• v.55 no.3
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• pp.369-378
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• 2017

Vascular endotherial growth factor (VEGF) is a potent mitogen that stimulates vascular permeability and angiogenesis and has a potential in therapeutic applications. An industrial production method that provides high yield as well as purity is needed. Researches for various factors of mild solubilization with combination of ubiquitin fusion protein to increase solubility were carried out as well as by changing pH and denaturant concentration. Usage of pET28-a bacteral expression vector in BL21 (DE3) host cell was capable of producing approximately 14 g/L VEGF fusion protein in 20L fermentor. A purification process consisting of four chromatography steps including refolding and digestion with UBP1 resulted in mild solublization under the conditions of 2M urea and pH 10.0 due to ubiquitin fusion tag protein that increases in solubility of target protein VEGF. High yield of refolding and dimerization could be obtained between two step Ni-affinity chromatography. Multimeric and misfolded proteins and endotoxin were removed by DEAE anion exchange chromatography. Final monomers were removed from dimers by gel filtration chromatography. Characterization analysis of purified dimeric VEGF was performed using SDS-PAGE and RP-HPLC with a purity of 97%.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.3
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• pp.198-204
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• 2000

In order to utilize by-products which would normally be discarded in marine processing plants, cod teiset protein was hydrolyzed and antioxidative actiTity of the hydrolysate was investigated. AntioxidatiTe peptide was isolated using ultrafiltration membrane, ion-exchange chromatography on a SP-Sephadex C-25 column, gel filtration on a Sephadex G-15 column, high performance liquid chromatography on an ODS column, and capillary electrophoresis chromatography. Antioxidative activities of the cod teiset hydrolysate were compared with ${\alpha}-tocopherol$, one of the commercial antioxidant. The hydrolysate passed through a membrane with molecular weight cut-off (MWCO) 1 kDa was shown the strongest antioxidative activity, and the activity was higher $10{\%}$ as compared with ${\alpha}-tocopherol$. In addition, the peptide isolated by ion-exchange chromatography, gel filtration, and HPLC, respectively, was higher $53{\%}$ as compared with ${\alpha}-tocopherol$, and the amino acid sequence was Ser-Asn-Pro-Glu-Trp-Ser-Trp-Asn.

• Analytical Science and Technology
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• v.25 no.4
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• pp.207-213
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• 2012

Analysis of the aroma constituents present in the rose essential oil of Chinese Kushui type (Rosa sertata ${\times}$ Rosa rugosa) by GC-FID and GC-MS was performed independently as an expert for the inter-laboratory round-robin test to verify reproducibility according to the decision of the preliminary meeting of ISO/TC-54 (Shanghai, Sep. 14-15, 2010). Total 179 peaks (using SPB-1 apolar column), 165 peaks (using DB-624 intermediate polar column), and 162 peaks (using Supelcowax-10 polar column) were separated by GC-FID, respectively. Major constituents (over 5%) by GC-FID were ${\beta}$-citronellol (41.6~46.7%), geraniol (9.7~11.0%), and nerol (3.4~4.5%). ${\beta}$-Citronellol peak was overlapped with nerol peak on SPB-1 and DB-624 columns, whereas the two peaks were separated each other on Supelcowax-10 column. Our results were generally consistent with Chinese data (ISO/DIS 25175); however, a peak of phenethyl alcohol separated by using PEG (Supelco wax) column was found at the quite different retention time. Comparative analysis was conducted using Bulgarian rose (Rosa damascena Miller) oil and perfume. Bulgarian rose oil showed rich amounts of characteristic aroma constituents than the essential oil of Chinese Kushui type.

• Applied Chemistry for Engineering
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• v.7 no.6
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• pp.1043-1052
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• 1996

Supercritical fluid chromatographic method was recommended as an alternative separation method of fatty acids of the conventional method such as distillation or extraction. Although diffusion characteristics are varied by the carbon numbers and the degree of unsaturation of fatty acids, the quantitative data were so rare that the commercialization of supercritical fluid chromatographic method has been hindered. In this study, diffusion coefficients of fatty acids which are differently unsaturated are measured by CPB method in the range of 308.15K to 328.15K and 13MPa to 17MPa in supercritical carbon dioxide. A decrease in the binary diffusion coefficient was observed with an increase in temperature and pressure. Also, the decrease in the binary diffusion coefficient with increasing fluid density and viscosity. Wilke-Chang equation, Funazukuri empirical equation, and Matthews-Akgerman equation are used to correlate the experimental diffusion coefficients of fatty acids in supercritical carbon dioxide. Among the various theoretical equations, Matthews-Akgerman equation based on RHS theory was suggested as a more successful correlation model with experimental data.