• KSBB Journal
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• v.14 no.1
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• pp.109-113
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• 1999

Supercritical $CO_2$ chromatography was applied for purification of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from fish oil. Various supercritical $CO_2$ pressures were tested to find out the pressure effects on solubility and selectivity of low fatty acids in the silver nitrate column. The solubility of low fatty acids was increased as the supercntical $CO_2$ Pressure increased. However, the selectiviy between low fatty acids and EPA waw decreased. Stepwise density gradient method was applied to increase the purification efficiency of EPA. Low fatty acids were easily separated at the early elution steps with low $CO_2$ densities. Successive fractions containing 92.1~97.8% of EPA were collected. The average concentration of three purified fractions was 95.6% with the recovery rate of 30%.

• Journal of the Korean Applied Science and Technology
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• v.24 no.2
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• pp.140-148
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• 2007

As an additional high purification method of p-dioxanone monomer for a high molecular weight polymer, the sweating operation of crystalline layer obtained by layered melt crystallization from p-dioxanone-diethylene glycol system was studied. Purity and yield of p-dioxanone crystal depended mainly on the sweating temperature and sweating time. Increasing sweating time and sweating temperature, the purity of p-dioxanone crystal increase, whereas the yield of that decrease, respectively. Through the optimization of sweating operation, p-dioxanone crystal can be upgraded to very high purity over 99.9 % suited to monomer for polymerization.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.6
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• pp.375-379
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• 2002

Methyl mercaptan oxidase was successfully induced in Thiobacillus thioparus TK-m using methyl mercaptan gas, and was purified for the detection of mercaptans. The purification procedure Involved a DEAE (diethylaminoethyl) -Sephacel, or Superose 12, column chromatography with recovery yields of 47.5 and 48.5%, and specific activities of 374 and 1240.8 units/mg-protein, respectively, The molecular weight of the purified methyl mercaptan oxidase was 66.1kDa, as determined by SDS-PAGE. The extract, from gel filtration chromatography oxidizes methyl mercaptan, producing formaldehyde, which can be easily detected by the purpald-coloring method. The optimized temperature for activity was found to be at 55$\^{C}$. This enzyme was inhibited by both NH$_4$Cl and (NH$_4$)$_2$SO$_4$, but was unaffected by either KCl or NaCl at less than 200 mM. With K$_2$SO$_4$, the activity decreased at 20 mM, but recovered at 150 mM. In the presence of methanol, full activity was maintained, but decreased in the presence of glycerin, ethanol and acetone 43, 78 and 75%, respectively.

• The Journal of Korean Society of Virology
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• v.28 no.1
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• pp.21-30
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• 1998

Synthetic genes encoding the gag p24 and the part of the envelope protein gp41 of the human immunodeficiency virus (HIV-1) were cloned and overexpressed as fusion proteins in Escherichia coli, using an expression vector carrying T7 promoter and the poly-histidine leader, sequence. The overexpressed p24 fusion protein was purified by centrifugation, Ni-affinity chromatography and CM-sepharose chromatography. The overexpressed gp41 fusion protein was purified by centrifugation, $C_4$ chromatography and DEAE-sepharose chromatography. The purified fusion proteins showed a high level of purity and immunoreactivity in SDS-polyacrylamide gel electrophoresis and western blot analysis. These results suggest that this prokaryotic - expression purification method is suitable for obtaining a large amount of the viral antigen which may be useful for screening of antibodies to HIV-1 in human blood samples.

• Journal of Acupuncture Research
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• v.34 no.1
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• pp.31-38
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• 2017

Objectives : The purpose of this study was to analyze the components of the clinically used bee venom (BV) pharmacopuncture. Methods : Two kinds of bee venom pharmacopuncture (BV-I and II), three kinds of separate purification BV (SPBV) pharmacopuncture (SPBV-I, II, and III), and apitoxin were investigated in this study. We performed a component analysis of melittin, apamin, and phospholipase $A_2$ using high-performance liquid chromatography (HPLC). Results :1. BV-I contained approximately 40% more melittin than BV-II did. 2. In the three separate purification BV pharmacopuncture, SPBV-I, SPBV-II, and SPBV-III, phospholipase $A_2$ content decreased remarkably. 3. The melittin content in SPBV-I increased by 5% compared to that in BV-I. 4. The amount of melittin in apitoxin was similar to that in SPBV-I. Conclusion : The compositions of the BV pharmacopuncture and separate purification BV pharmacopuncture changed depending on the collection method and concentration. Therefore, it is necessary to choose the most suitable BV for each specific medical treatment target. Furthermore, research into the composition of BV may be needed for its safe and effective use.

• International Journal of Naval Architecture and Ocean Engineering
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• v.7 no.1
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• pp.212-225
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• 2015

In order to preserve the quality of fresh water in the artificial lake after the reclamation of an intertidal flat at the mouth of a river, we suggest two novel methods of water purification by using tidal potential energy and an enclosed permeable embankment called an utsuro (Akai et al., 1990) in the reclaimed region. One method uses an inflatable bag on the seabed within an utsuro, while the other uses a moored floating barge out of a dyke. Each case employs a subsea pipe to allow flow between the inside and outside of the utsuro. The change in water level in the utsuro, which is pushed through the pipe by the potential energy outside, caused circulation in the artificial lake. In this paper, we analyzed the inflatable bag and floating barge motion as well as the pipe flow characteristics and drafts as given by a harmonic sea level, and compared the theoretical value with an experimental value with a simple small model basin. The numerical calculation based on theory showed good agreement with experimental values.

• BMB Reports
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• v.40 no.1
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• pp.113-118
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• 2007

Tolaasin, a pore-forming peptide toxin, is produced by Pseudomonas tolaasii and causes brown blotch disease of the cultivated mushrooms. P. tolaasii 6264 was isolated from the oyster mushroom damaged by the disease in Korean. In order to isolate tolaasin molecules, the supernatant of bacterial culture was harvested at the stationary phase of growth. Tolaasin was prepared by ammonium sulfate precipitation and three steps of chromatograpies, including a gel permeation and two ion exchange chromatographies. Specific hemolytic activity of tolaasin was increased from 1.7 to 162.0 HU $mg^{-1}$ protein, a 98-fold increase, and the purification yield was 16.3%. Tolaasin preparation obtained at each purification step was analyzed by HPLC and SDS-PAGE. Two major peptides were detected from all chromatographic preparations. Their molecular masses were analyzed by MALDI-TOF mass spectrometry and they were identified as tolaasin I and tolaasin II. These results demonstrate that the method used in this study is simple, time-saving, and successful for the preparation of tolaasin.

• Journal of Microbiology and Biotechnology
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• v.17 no.5
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• pp.840-846
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• 2007

Human prostate-specific antigen(PSA), a 33 kDa serine protease with comprehensive homology to glandular kallikrein, is secreted from prostatic tissue into the seminal fluid and enters into the circulation. The level of PSA increases in the serum of patients with prostatic cancer and hence is widely employed as a marker of the disease status. In particular, an enzymatically active PSA that is a form cleaved at the N-terminal seven-amino-acids prosequence, APLILSR, of proPSA may play an important roll in the progression of prostate cancer. Thus, the presence of the active form would selectively discriminate the cancer from benign prostatic hyperplasia. In this study, we developed a convenient purification method for the acquisition of active PSA and proPSA. Recombinant proPSA and active PSA were expressed directly in Escherichia coli, easily and efficiently isolated from inclusion bodies, refolded, and purified. Moreover, the enzymatic activity of the recombinant active PSA was confirmed as serine protease using chromogenic chymotrypsin substrate. This purified active PSA could be further applied to scrutinize the biological or conformational characteristics of the protein and to develop specific diagnostic and/or therapeutic agents against prostate cancer.

• Journal of Integrative Natural Science
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• v.6 no.4
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• pp.193-196
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• 2013

Haemoglobin is an interesting physiologically significant protein composed of specific functional prosthetic haem and globin moieties. In recent decades, there has been substantial interest in attempting to understand the structural basis and functional diversity of avian haemoglobins (Hbs). Towards this end, purification, crystallization, preliminary X-ray diffraction and molecular-replacement studies have been carried out on Amaurornis phoenicurus Hb. Crystals were grown by the hanging drop vapor-diffusion method using PEG 2000 and NaCl as precipitants. The crystals belonged to the primitive monoclinic system $P2_1$, with unit-cell parameters $a=65.33{\AA}$, $b=93.14{\AA}$, $c=98.54{\AA}$, ${\beta}=100.48^{\circ}$; a complete data set was collected to a resolution of $2.6{\AA}$. The Matthews coefficient of $2.30{\AA}^3Da^{-1}$ for the crystal indicated the presence of two ${\alpha}_2{\beta}_2$ tetramers in the asymmetric unit.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.336-336
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• 1994

In order to develope the in vitro short term screen-ing method for carcinogen, we studied a purification method for thymine glycol in oxidaized DNA. Thymine glycol (5,6-dihydroxy-5, 6-dihydrothymine) is the major stable radiolysis poduct in thymine by chemical oxidants and ionzing radiation and it is a useful biomarker among oxidized DNA adducts, related with carcinogenests. Standard thymine glycol was prepared by oxidation of 〔$^3$H〕 thymine with KMnO$_4$ followed by purification with HPLC-LSC system and it was assayed by TLC and gas chromatography-MSD. 〔$^3$H〕 DMA adducts was isolated from E. coli (wild type ) treated with oxidative agents such as benzo(a)pyrene, adriamycin, aflatoxin B$_1$ and KBrO$_3$. These oxidative agents generated free radicals in cells by oxidative metabolism. As a result, thymine glycol was produced in cultured E. coli by four chemicals. This result shows that this methodology should be useful tool in screening oxidative carcinogen.