• Microbiology and Biotechnology Letters
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• v.2 no.2
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• pp.111-117
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• 1974

Studies were carried out on the practical use of Naringinase and some chracteristics of Naringin solublizing enzme which might hydrolyae naringin to purunin. Obtained results were as follows. 1. Selected strain for Naringinase producing was identified to be Aspergillus niger S-1 and its naringinase was applied to chinese citron processing to remove the bitter taste. 2. Of the naringinase, naringin solubilizing enzyme was purified on a DEAE-Sephadex A-50 column and crystalized from acetone and ammonium sulfate. 3. Hydrolized naringin which has higher solubility rather than naringin or naringenin were identified by thin layer chromatography. 4. Hydrolyzed naringin and naringin were separatly determinated by ethylacetate extraction and this result was compared with sensory test.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.2
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• pp.83-88
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• 2005

Protease inhibitors were purified from the eggs of Alaska pollock (Theragra chalcogramma) using the following purification steps: ammonium sulfate precipitation, ion exchange, gel permeation, and high performance liquid chromatographies (HPLC). The protease inhibitor from the heated eggs of Alaska pollock was not as well purified. In addition, the heated eggs showed lower specific inhibitory activity than the unheated eggs. The purification yields after ammonium sulfate precipitation, ion exchange, and gel permeation chromatographies were 22.7$\%,\;15.3\%$,and $4.4\%$, respectively. There were two kinds of protease inhibitors on the gel permeation chromatography pattern Their molecular weights were estimated to be 66,700 and 16,000 Da, respectively. Both were classified as a cysteine protease inhibitor because of the existence of inhibiting papain, which is one of cysteine proteases.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.184-184
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• 1996

Nitric Oxide Synthase(NO synthase: EC.1.14.13.39)는 생체내에서 L-arginine을 기질로 하여 nitric oxide(NO)와 L-citrulline의 생성을 매개하는 효소로서 뇌, 간장, 신장, 체장등 대부분의 주요장기와 근육세포, 신경세포 등 거의 모든 조직에 분포하고 있다. NO synthase에 의해 생성되는 NO는 혈관이완작용, 신경전달 물질로서의 작용, 면역 담당세포에서의 세포 독작용 등 많은 생리현상에 중요한 역할을 하는 것으로 알려져 있다. 특히 체장에서는 췌외분비 기능의 항진에 있어 세포내 cGMP level의 변동이 NO와 연관된다는 사실에 주목하고 있으며 본연구실에서도 이에 관한 연구가 진행중이다. 따라서 본 연구에서는 소 췌조직의 100,000$\times$g cytosol을 효소원으로 하여 다음과 같이 NO synthase의 분리, 정제를 시행하였다. Ammonium sulfate로 30%(176g solid ammonium sulfate/$\ell$) 포화, 침전 후 2',5'-ADP agarose 및 calmodulin-agarose affinity chromatography를 연속적으로 시행하여 NO synthase를 분리하였으며 electrophoresis상에서 약 160kd의 분자량을 나타내었다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.20
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• pp.122-133
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• 1975

In recent years, farmers have substituted urea for ammonium sulfate as nitrogen fertilizer in their crop production. Since crops can not take urea itself directly as it is, we attempted to determine the amount of decomposition of urea in soil. It was observed that 25 percent of urea which had initially mixed with soil was decomposed in 10 days at 15$^{\circ}C$ and 80 percent in 2 days at $25^{\circ}C$. Therefore, it was considered that large amount of urea could be lost in cool season and cool areas. In the other experiment, ammonium sulfate, as a source of sulfur, was so mixed with urea that the ratio of sulfur to nitrogen would be 15 percent. Small amount of dolomite was also added to this mixture and the resulting fertilizer was applied on the rice plants. Eight percent of yield increase was obtained together with the increased protein content in brown rice.

• Microbiology and Biotechnology Letters
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• v.18 no.6
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• pp.585-590
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• 1990

The cyclodextrin glucanotransferase (CGTase) was purified from the culture broth of Bacillus stearothermophilus by ammonium sulfate precipitation and affinity chromatography. The specific activity of the CGTase increased by about 31-fold from 111.5 U/mg protein to 3445.0 Ulmg protein. The SDSPAGE indicated that the purified CGTase was homogeneous and the molecular weight of the purified CGTase was about 78,000. The optimum pH and temperature was 6.0 and $60^{\circ}C$, respectively. This enzyme was stable from pH 5.5-10.0. The enzyme retained its full activity at the incubation temperature up to $60^{\circ}C$ and calcium ion increased the thermal stability. The isoelectric point was about 4.8.

• Microbiology and Biotechnology Letters
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• v.19 no.6
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• pp.592-597
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• 1991

An extracellular xylanase of Bacillus stearothemophilus was purified to a single protein through a sequency of operations including ammonium sulfate fractionation, DEAE Sepharose CL-6B ion exchange chromatography, Sephadex G-100 gel filtration and heat treatment. The purified enzyme had a moleular weight of 170, 000. the pH and temperature optima for the enzyme activity were pH 9.0 and $55^{\circ}C$, respectively. The activity was enhanced by $co^{2+} \; and\; Mn^{2+}$, and inhibited by $Hg^{2+}$. Pattern of hydrolysis demonstrated that the xylanase was an endo-splitting enzyme able to break down larchwood xylan at random giving xylobiose and xylotriose as the main end products.

• Applied Biological Chemistry
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• v.36 no.4
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• pp.255-259
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• 1993

Chitobiase from Aeromonas salmonicida YA7-625 was purified from culture broth through ammonium sulfate precipitation, chitin affinity adsorption, hydroxylapatite column chromatography and gel filtration, with 47.2% yield and 31.5 fold purity. The molecular weight of purified chitobiase was 15,000 daltons, and the chitobiase showes maximum activity at the condition of at $40^{\circ}C$ and pH 6.0. The effects of various metal ions and inhibitors show thatcystein, glutamic acid, serine, tryptophan, and tyrosine residues seem to be concerned in chitobiase activity.

• Journal of the Korean Applied Science and Technology
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• v.19 no.4
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• pp.339-348
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• 2002

Self-diffusion coefficients of colloidal ass9Ciation structures in the aqueous solutions of anionic ammonium dodecyl sulfate (ADS) and cationic octadecyltrimethylammonium chloride (OTAC) surfactants were measured by pulsed-gradient spin echo NMR. The results were interpreted on the basis of the ADS/OTAC/water phase diagram. Crossing the phase boundaries, significant changes in self diffusion coefficients were observed and well correlated to the phase diagram. For the micelles their apparent radii were obtained from Stokes-Einstein equation. Their values were 15 for the ADS micelles and 54 ${{\AA}}$ for the OTAC micelles, respectively. For vesicles which were formed spontaneously at different relative amounts of the surfactants and total surfactant concentrations, the radius was measured as 50 to 200 nm. This result is in fair agreement with those by TEM and light scattering.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.3
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• pp.176-181
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• 2008

To evaluate the effective use of endoprotease from squid viscera as a food processing aid, various methods of fractionating endoprotease from viscera of the Argentina shortfin squid (Illex argentinus) were evaluated. The endoprotease-positive fractions of each fractionation were fraction II (30-40%, w/w) with cold acetone, fraction IV (50-60% saturation) with ammonium sulfate, fraction UF with anion exchange chromatography, and fraction II (15-24 kDa) with gel filtration. The specific activities (approximately 25 U/mg) of the fractions using ammonium sulfate and gel filtration were higher than the others. Total azocaseinolytic activity and recovery of the positive fraction using gel filtration were 806.95U and 37.82%, respectively, and were the highest among the positive fractions. Based on the results, gel filtration was the most efficient method for fractionating endoprotease from the viscera of Illex argentinus.

• Microbiology and Biotechnology Letters
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• v.20 no.5
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• pp.559-564
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• 1992

To increase the efficency of utilizing cellulosic biomass, a potent xylanase producing bacteria was isolated and identified as Bacillus sp. N-25. Extracellular xylanase from Bacillus sp. N-25 was partially purified by ammonium sulfate precipitation, DEAE-Sephadex A-25 and Sephadex G-IOO column chromatographies. The xylanase was single fraction on chromatography and was true xylanase without cellulase activity. The enzyme was stable at pH 6-8 and 80% activity was remained at $50^{\circ}C$ for 30 min, but was inhibited by $Hg^{2+}$, $Ag^{2+}$, and $Mn^{2+}$. From the fact that the major end product was xylose, we suggested that the enzyme is an exo-xylanase which may be a prime candidate for industrial use.