• Applied Biological Chemistry
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• v.47 no.1
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• pp.41-48
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• 2004

Cyclodextrin glucanotransferase (CGTase) of Bacillus sp. isolated from soil was purified and its enzymological characteristics were investigated. It was found that the production of CGTase reached to the maximum when the strain was cultured in the broth containing 0.1 % albumin, 2% $NH_4Cl$, 2% soluble starch and 0.2% $NH_2PO_4$ for 72 hrs at $37^{\circ}C$. The purity of CGTase was increased by 9.7 folds through purification procedures by the following column chromatography DEAE-cellulose ion exchange chromatography and Sephadex G-100, G-150 gel filtration and its specific activity was 528.0 unit/mg. The optimum pH and temperature for the CGTase activity were 8.0 and $80^{\circ}C$, respectively. The enzyme was stable in pH $8.0{\sim}11.0$ at $60{\sim}80^{\circ}C$. The activity of purified enzyme was inhibited by $Pb^{2+},\;Hg^{2+}$ and $Zn^{2+}$. When CGTase was treated with each 20.5 unit, 41 unit, 205 unit and 410 unit to investigate the transglucosylation to stevioside by purified cyclodextrin glucanotransferase, transglucosylation rate to stevioside was 74.9%, 75.7%, 68.7% and 57.9%. Brown effect was observed above the concentration amounting to 205 unit of our CGTase.

• Korean Journal of Microbiology
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• v.40 no.4
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• pp.269-274
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• 2004

Serratia proteamaculans isolated from the midgut of a spider formed big halos around the bacterial colonies, indicating that the bacterial strain produces an extracellular protease. Activity staining of the extracellular pro­tein fractions using zymogram also demonstrated that the major protein with an estimated molecular mass of 52 kDa contained a high proteolytic activity. The protease was purified to near electrophoretic homogeneity from the culture supernatant after filtration and ion exchange and size exclusion chromatography. The purified enzyme had a relatively high proteolytic activity between pH 6.0 and 10.0 and at broad temperature range. The proteolytic activity of the enzyme was not inhibited by phenylmethylsulfonyl fluoride but strongly inhibited by 1, 10-phenanthroline and EDTA. The activity also was dependent on the presence of $Ca^{++}\;and\;Zn^{++}$ ions. These observations indicate that the enzyme is a metalloprotease.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.2
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• pp.193-204
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• 1984

The enzymatic properties of the alkaline AL-protease, which had been prepared from the crude zymolyase of Arthrobzoter luteus, was investigated together with its active amino acid residue. Complete inactivaton of the proteolytic activity of AL-protease by either DFP or PMSF was simultaneously accompanied by the loss of its lytic effect on the lysis of yeast cell wall. In the reaction, AL-protease showed the pattern of inactivation to decrease very slowly, as compared to that of chymotrypsin, and that enzyme and DFP were found to react with a molar ratio of 1 : 1. The preparation of AL-protease exhibited no hydrolytic activity in any substrates of polysaccharases, playing a significant role in the lysis of yeast cell wall. The optimum pH and temperature of AL-protease was pH 10.5 and $65^{\circ}C$, respectively. It also showed stability in the pH range from 5 to 11 and at the temperature below $65^{\circ}C$. Through the identification of the amino acid residue in the active site of the $^{32}P$-diisopropylph-osphorylated(DIP) AL-protease modified specifically with $^{32}P$-labeled DFP, AL-protease was found to be a DFP-sensitive which has a mole of active serine residue involved in its proteolytic activity per mole of the enzyme.

• Journal of Life Science
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• v.12 no.1
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• pp.87-95
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• 2002

It was observed that the hot water extract of the leaves of Capsicum annuum L., a Korean edible plant, had a potent anti-complementary activity. Crude polysaccharide fraction(CAL-0) was obtained by methanol reflux, ethanol precipitation, dialysis and lyophilization. CAL-0 contained 51.8% of total sugar, 8.2% of uronic acid and 16.8% of protein, and consisted of mainly arabinose, galactose and glucose as neutral sugars and galacturonic acid as uronic acid. The anti-complementary activity of CAL-0 decreased greatly by periodate oxidation, but was not changed by pronase treatment. Also, the anti-complementary activity of CAL-0 was reduced partially in the absence of the $Ca^{2+}$ ion. The crude polysaccharide CAL-0 was found to activate the C3 component both in the presence and in the absence of $Ca^{2+}$ through the crossed-immunoelectrophoresis suggesting that those involved in both classical and alternative complement pathway CAL-0 was further separated to an unabsorbed fraction(CAL-1) and six absorbed fractions(CAL-2longrightarrowCAL-7) on DEAE Sepharose CL-6B ion exchange column. Among them four major fractions in activity and yield were obtained, and consisted mainly of arabinose, galactose and glucose with various molar ratios. The major fraction, CAL-2, was purified to give a high molecular fraction(CAL-2-I) and a low molecular fraction(CAL-2-II) on Sepharose CL-6B column. The anti-complementary activity of CAL-2-I, a molecular weight of about 61,000, was higher than it of CAL-2-II.-II.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.2
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• pp.177-181
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• 2009

The peptides from Aroase AP10 enzymatic hydrolysates of octopus proteins were isolated and tested for inhibitory activity against angiotensin converting enzyme (ACE). The Aroase AP10 hydrolysates were filtered through PM-10 membrane (M.W. cut-off 10,000) to obtain the peptides fractions with ACE inhibition activity. These fractions were applied to a Biogel P-2 column. Three active fractions (A, B, and C) were collected and applied to a SuperQ-Toyopearl 650S column chromatography, leading to the isolation of four active fractions (A-1, A-2, B-1, and C-1). Among the active fractions, C-1 had the highest ACE inhibitory activity ($IC_{50}=3.10{\mu}g$). The main composition of its amino acids is arginine, lysine, histidine and leucine, which cover about 60% of the total amino acids.

• Analytical Science and Technology
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• v.15 no.1
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• pp.20-25
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• 2002

An accurate and simple analytical technique for $^{89}Sr$ and $^{90}Sr$, overcoming the demerits of the conventional method, has been developed with extraction chromatography and liquid scintillation counting. The Sr fraction was separated from hindrance elements with oxalate coprecipitation or cation exchange resin and purified with Sr-Spec column. With liquid scintillation counter, $^{89}Sr$ was measured by Cerenkov radiation method, and $^{90}Sr$ was measured by spectrum unfolding method. The developed radioactive strontium separation method was validated by application to the IAEA-reference material (IAEA-375, Soil) and radioactive waste samples.

• Korean Journal of Food Science and Technology
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• v.25 no.5
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• pp.576-581
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• 1993

Polygalacturonase(PG) was extracted from Chinese cabbage and partially purified by ammonium sulfate fractionation and ion-exchange chromatography. Three fractions, D-PG, C-1 PG, and C-2 PG, were separated by CM-Sephadex C-25 column chromatography and FPLC Mono Q HR 5/5 or Mono S HR 5/5 column and their physicochemical characteristics were investigated. All three fractions had optimum pH and temperature of 4.5 and $65^{\circ}C$, and were stable in the range of pH $4.5{\sim}8.0$. These fractions were inhibited by 0.8mM $CaCl_2$ or 0.6M NaCl. In the thermal inactivation of PC isozymes at $65{\sim}80^{\circ}C$, z-values were $8.4{\sim}9.3^{\circ}C$ and D-values at $80^{\circ}C$ were In the range of $120{\sim}126s$. Thermodynamic constants were calculated from thermal inactivation data of the isozymes and were applicable to estimation of thermal process time of retort pouched Kimchi.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.351-357
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• 2003

Transuranic elements such as Pu, Am and Cm in synthetic solution of spent nuclear fuel samples were determined by electrodeposition followed by alpha-spectrometry after separation using anion exchange and extraction chromatography in order to determine the transuranic elements in radwaste samples from nuclear power plants. Plutonium was separated by 12M HC1-0.1M HI as an eluent on anion exchange column. As a second step Am and Cm were separated in a group by DTPA-Lactic acid as the eluent on HDEHP coated column. The nuclides of $^{239}Pu$, $^{241}Am$및 $^{244}Cm$ separated were determined by alpha-spectrometry after electrodeposition in 0.1M $NaHSo_4$-0.53M $Na_2SO_4$buffer solution as an electrolyte. The recovery yields of $^{239}Pu$, $^{241}Am$및 $^{244}Cm$ were 83.8%, 85.2% and 86.3%, respectively, from the synthetic solution containing uranium and non-radioactive metal elements.

• Korean Chemical Engineering Research
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• v.55 no.1
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• pp.99-106
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• 2017

In this study, mixed catalytic char gasification of Indonesia low-rank coal Kideco was investigated under nitrogen atmosphere and isothermal conditions at a fixed reactor. The effects of the temperature were investigated at various temperature (700, 750, 800, $850^{\circ}C$). The effects of blend ratio of catalysts ($K_2CO_3$, Ni) were investigated with different blend ratios (1:9, 3:7, 5:5, 7:3 and 9:1). The sample was prepared by mixing with $K_2CO_3$ physically and by ionexchange method with Ni. The data from thermogravimetric analyzer and gas chromatography were applied to four gassolid reaction kinetic models including shrinking core model, volumetric reaction model, random pore model and modified volumetric reaction model.

• Korean Journal of Agricultural Science
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• v.25 no.1
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• pp.131-137
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• 1998

The cellulase components were partially purified from the culture filtrate of the alkalophilic bacterium Pseudomonas sp. AC-711 and its enzymatic properties were characterized. The specific activity of the purified major enzyme component was 3.5 units/mg protein as carboxymethyl cellulase and the yield was 23% of the total activity of the culture broth. The molecular weight of the component was 46,000 and the Km and Vmax on CMC were determined as $15.4mg\;mL^{-1}$ and $4.17{\mu}moles\;mL^{-1}\;min^{-1}$, respectively. The enzyme was stable at the temperatures below $60^{\circ}C$ and at the pH range of 4.0~11.0, and the optimal temperature and pH were $60^{\circ}C$ and pH 8.0, respectively. The enzyme activity was not significantly affected by the common surfactants (concentration: 0.05%) such as ${\alpha}$-olefin sulfonate, linear alkylbenzene sulfonate, sodium dodecyl sulfonate, hexadecyltrimethylammonium bromide and Tween 80. The enzyme was activated by the metal ions such as $Ca^{2+}$, $Cu^{2+}$, $Co^{2+}$, whereas inhibited by $Hg^{2+}$ and $Zn^{2+}$. The enzyme exhibited relatively high activity toward amorphous CMC as compared with crystalline substrates such as filter paper and avicel.