• 한국식품영양과학회지
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• 제24권4호
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• pp.636-641
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• 1995

Proteolytic activities were compared using three species involving in squid jeotkal fermentation and showing positive reaction upon casein test : Pseudomonas D2, Flavovacterium odoratum and Acinetobacter calcoaceticus. Pseudomonas D2 produced highest activity of protease at 72h when incubated in our own modified medium(polypeptone, 0.5% ; tryptone, 0.5% ; NaCl, 3% ; pH, 7.5). Thus, this specie was selected for the further study. The growth pattern was coincided with the production of protease. Thus purification of protease was proceeded by ethanol precipitation, sephadex G-100 gel filtration, and DEAE sepharose ion exchange chromatography. The purified protease showed highest activity at pH 7.0 and 5$0^{\circ}C$. The enzyme was very stable over the wide ragnes of the temperature ; even with one hour heat treatment at 7$0^{\circ}C$, the enzyme showed substantial amount of the activity toward casein. In addition, the enzyme was stable over the wide range of pH. Molecular weight of the protease was determined to be 17.4 kD by SDS-PAGE.

• Mycobiology
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• 제35권4호
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• pp.219-225
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• 2007

A keratinolytic enzyme secreted by Aspergillus flavus K-03 cultured in feather meal basal medium (FMBM) containing 2% (w/v) chicken feather was purified and characterized. Keratinolytic enzyme secretion was the maximal at day 16 of the incubation period at pH 8 and $28^{\circ}C$. No relationship was detected between enzyme yield and increase of fungal biomass. The fraction obtained at 80% ammonium sulfate saturation showed 2.39-fold purification and was further purified by gel filtration in Sephadex G-100 followed by ion exchange chromatography on DEAE-Sephadex A-50, yielding an active protein peak showing 11.53-fold purification. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and zymograms indicated that the purified keratinase is a monomeric enzyme with 31 kDa molecular weight. The extracellular keratinase of A. flavus was active in a board range of pH ($7{\sim}10$) and temperature ($30^{\circ}C{\sim}70^{\circ}C$) profiles with the optimal for keratinase activity at pH 8 and $45^{\circ}C$. The keratinase activity was totally inhibited by protease inhibitors such as phenylmethylsulfonyl fluoride (PMSF), iodoacetic acid, and ethylenediaminetetraacetate (EDTA) while no reduction of activity by the addition of dithiothreitol (DTT) was observed. N-terminal amino acid sequences were up to 80% homologous with the fungal subtilisins produced by Fusarium culmorum. Therefore, on the basis of these characteristics, the keratinase of A. flavus K-03 is determined to be subtilisins-like.

• Preventive Nutrition and Food Science
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• 제7권2호
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• pp.157-161
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• 2002

Thirty plants of the Compositae family were screened for inhibitory activity of angiotensin converting enzyme (ACE). Among them, Chrysanthemum boreale Makino and Ixeris dentate Nakai were selected for further investigation since they had the highest inhibitory activity. Crude water extracts of the flowers of Chrysanthemum boreale Makino and the roots of Ixeris dentate Nakai were prepared by heating at 95$^{\circ}C$ and 6$0^{\circ}C$ for 2 hr, respectively, followed by centrifugation at 8000$\times$ g far 30 min. Crude extracts were then filtered using YM-3 and YM-1 membranes. The ACE inhibitors were isolated using consecutive chromatographic methods including: Sephadex G-15, ion exchange, FPLC, and reverse phase HPLC. The inhibitors were identified to have molecular masses of 204 and 283 daltons, respectively, by mass spectrometry. These results demonstrate that crude extracts of Compositae plants may be useful as functional food ingredients with anti-hypertensive properties.

• 한국수산과학회지
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• 제43권6호
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• pp.606-613
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• 2010

In order to elucidate a mechanism responsible for the development of the odor characteristics of cooked, desirable-flavored shellfish, oysters were extracted using various solvents and the resulting extracts were evaluated organoleptically after cooking. The 80% aqueous methanol extract was found to produce a desirable cooked flavor. This oyster extract was fractionated using ion-exchange column chromatography and dialysis, and each of the fractions was subjected to cooking, followed by organoleptic evaluation. The outer dialysate fraction such as acidic and amphoteric water-soluble fractions produced a cooked oyster flavor. The volatile flavor compounds identified from cooked oyster included 29 hydrocarbons, 20 alcohols, 16 acids, 12 aldehydes, nine nitrogen-containing aromatic compounds, eight ketones, five furans, three esters, three phenols, and one benzene.

• 미생물학회지
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• 제21권3호
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• pp.135-142
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• 1983

The presence of polyphosphate phosphohydrolase (PPPH) and tripolyphosphate phosphohydrolase (TPPH) in Chlorella ellipsoidea were confirmed from the cell-free extract of the algal cells and three forms of PPPH were isolated, purified, and measured Km-Vmax value and inhibitory effect by metal ions, respectively. PPPH was most active at pH7.2, whereas TPPH at pH 7.6. Both enzymes exhibited their maximum activity at $37^{\circ}C$. For the manifestation of catalytic activity, divalent, divalent metal ions are needed, and the best activator for both enzymes was $Co^{++}\;ions\;(10^{-3}M)$. These enzymes were inhibited by $Hg^{++}\;ions\;(10^{-3}M)$ considerably. PPPH from Chlorella ellipsoidea was purified by ammonium sulfate fractionation, ion-exchange chromatography on DEAE-Sephadex A-25, and gel filtration on Sephadex G-100, and some properties of the three different fraction with PPPH activity $(PPPH_1,\;PPPH_2,\;and\;PPPH_3)$ were found, i.e, PPPH has multiple form. The Km values of $PPPH_1,\;PPPH_2,\;and\;PPPH_3$ obstained were $6.25{\times}10^{-4}M,\;10^{-4}M-4/M,\;and\;3.33{times}10^{-4}M$ and Vmax were 3.33 mM/min, 3.33 mM/min, and 2.67 mM/min, respectively. It was shown that the types of inhibition of $Hg^{++} on the activities of three forms of PPPH were competitive inhibition.

• 한국수정란이식학회지
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• 제13권1호
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• pp.43-52
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• 1998

The embryogenesis stimulating activity(ESA) had been shown in co-culture of embryos with bovine oviduct epithelial cell(BOEC) and culture in BOEG-conditioned medium. The present study was undertaken to purify and quantify the embryotropic proteins and to determine the optimum concentration of the embryotropic protein for the proper development of embryos. In BOEC-conditioned medium, five major bands of proteins were detected(66, 53, 40, 32 and 24 kDa) by SDS-PAGE. From these proteins, 288pg of protein that had a 32kDa molecular weight was purified by gel filtration column and perfusion chromatography ion-exchange column. When purified protein was supplemented to the in vitro culture media at various concentrations in protein-free media, 2.5$\mu$g /ml supplement group showed significantly higher rates of embryo development into morula /blastocyst stages than other groups(p<0.05). In conclusion, we purified 32kDa protein from BOEC-conditioned medium and this protein showed optimum embryogenesis stimulating effect at 2.5$\mu$g /ml.

• Food Science and Biotechnology
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• 제18권2호
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• pp.519-525
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• 2009

A bacterial strain (Strain N-08) capable of extracellularly producing high level of non-reducing oligosaccharide (NR-OS) isolated from soil. The strain was identified phylogenetically by 16S rDNA sequence analysis and found to be very close to Arthrobacter crystallopoietes. The high production of NR-OS was observed in the basal culture medium containing maltose as a sole carbon source. The NR-OS in culture supernatant was purified by glucoamylase treatment and Dowex-1 (OH.) ion exchange chromatography and its structure was characterized. This oligosaccharide consisted of only glucose. Methylation analysis indicated that this fraction was composed mainly of non-reducing terminal glucopyranoside. Matrixassisted laser-induced/ionization time-of-flight (MALDI-TOF) and electrospray ionization-mass spectrometry (ESI-MS)/MS analyses suggested that this oligosaccharide comprised non-reducing disaccharide unit with 1,1-glucosidic linkage. When this disaccharide was analyzed by $^1H$-NMR and $^{13}C$-NMR, it gave the same signals with $\alpha$-D-glucopyranosyl-(1,1)-$\alpha$-Dglucopyranoside. These results indicated that the NR-OS produced by A. crystallopoietes N-08 was ${\alpha}1$,${\alpha}1$-trehalose. This is the first report of the trehalose which can be produced directly from maltose by A. crystallopoietes N-08.

• 한국식품영양학회지
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• 제7권3호
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• pp.159-168
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• 1994

From the hot water extract of bracken(Pteridium aquilinum var. latiusculum), a Korean win edible plant, anti-complementary acidic polysaccharides were Isolated. Crude polysaccharide fraction(HPA-1) was obtain ed by methanol reflux, ethanol precipitation, dialysis, and lyophilization. HPA-1 contained 81.80% of total sugar, 30.40% of uronic acid, and 15.60cA of protein. HPA 1 was purified consecutively by cetavlon fractionation and chromatography including ion exchange nth DEAE-Sepharose CL 6B and gel permeation with Sephadex G-100 and Sepharose CL-6B. HPA-2- IVa and HPA-Va-2 were nearly homogeneous on HPLC and had 500,000 and 560,000 daltons of molecular weights, respectively. HPA-2-Wa consisted of fucose, galacturonic acid, and glucuronic acid at the molar ratio of 1.40 : 0.97 : 1.88. HPA-2-Va 2 was composed of rhamnose, galactose, and galacturonic acid at the molar ratio of 1.00 : 1.38 : 1.39. The polysaccharides were found to activate the C3 component both In the presence and In the absence of Ca2+ through the crossed-immunoelectrophoresis suggesting that those Involved in both classical and alternative complement pathway.

• 생명과학회지
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• 제8권2호
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• pp.145-157
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• 1998

We isolated 100 Vobrio sp. from marine products and sea from July to September, 1997. We attemped on purification of hemolysin produced by Vibrio sp. The growth, hemolysin production patterns by the 100 strains of Vibrio sp. showed identical, in general. V. unlnificus ys-1 produced hemolysis as the higtest titer. The optimal culture conditions for the hemolysin production by the V. vunificus ys-1 are followings; 1. Hemolysin production was optimal dering the late exponetial phage. 2. Maximal growth, hemolysin production were in heart infusion broth. 3. Maximal yields of hemolysin was obtained when the heart infusion broth had an intial pH of 8.0, 3$0^{\circ}C$, 3% NaCL. Hemolysin was purified from culture filtrate of the strain by ammonium sulfate recipitation, ion exchange and hydrophobic interaction chromatography. The results were as follows; 1. Hemogeneity of the purified hemolysin was demonstrated by revealing single band on SDS-PAGE. The molecular weight of purified hemolysin was 45KDa. 2. The absorbance rattern in ultraviolet wsa typical of those seen with most proteinb with 280nm. 3. Purified hemolysin was atable at 5$0^{\circ}C$ but 7$0^{\circ}C$ of the acivity was lost by heating for 30 min at 6$0^{\circ}C$/ Optimal temperature of purified hemolysin was 35$^{\circ}C$. 4. Purified hemolysin was stable at the pH range of 6~9, but in the less the pH5.0. above the pH 9.0, the hemolysin activity was lost completely.

• Nuclear Engineering and Technology
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• 제42권5호
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• pp.600-607
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• 2010

Rhenium-186, having a half-life of 90.64 h, is an important radionuclide, used in metabolic radiotherapy and radio immunotherapy. $^{186}Re$ hydroxyethylidene diphosphonate (HEDP) is a new compound used for the palliation of painful skeletal metastases. Its production is achieved via charged-particle-induced reactions; the data are available in EXFOR library. For the work discussed in this paper, production of $^{186}Re$ was done via $^{nat}W(p,n)^{186}Re$ nuclear reaction. Pellets of $^{nat}W$ were used as targets and were irradiated with 15, 17.5, 20, 22.5, 25 MeV proton beams at 5 ${\mu}A$ current. The radiochemical separation was performed by the ion exchange chromatography method. The production yield achieved at 25 MeV was 1.91 $MBq{\cdot}{\mu}A^{-1}{\cdot}h^{-1}$. Excitation functions for the $^{186}Re$ radionuclide, via $^{186}W(p,n)^{186}Re$ and $^{186}W(d,2n)^{186}Re$ reactions were calculated by ALICE-ASH and TALYS-1.0 codes to validate and fit the experimental data and to obtain a recommended set of data for $^{186}W(p,n)^{186}Re$ reaction. Required thickness of the targets was obtained by SRIM code for each reaction.