• Journal of Microbiology and Biotechnology
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• 제6권3호
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• pp.151-161
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• 1996

• 한국미생물·생명공학회지
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• 제50권1호
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• pp.71-80
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• 2022

Lipases (triacylglycerol acylhydrolases [EC 3.1.1.3]) are water-soluble enzymes. They catalyze the hydrolysis of fats and oils. A cold-active lipase from marine Bacillus cereus HSS, isolated from the Mediterranean Sea, Alexandria, Egypt, was purified and characterized. The total purification depending on lipase activity was 438.9 fold purification recording 632 U/mg protein. The molecular weight of the purified lipase was estimated to be 65 kDa using sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. The optimum substrate concentration, enzyme concentration, pH, and temperature were 1.5 mM, 100 µl, pH 6 and 10℃, respectively. The lipase was tolerant to NaCl concentrations ranging from 1.5 to 4.5%. The lipase was affected by the tested metal ions, and its activity was inhibited by 16% in the presence of 0.05 M SDS. The application of the cold-active lipase for the removal of an oil stain from a white cotton cloth showed that it is a promising biological agent for the treatment of oily wastes and other related applications. To the best of our knowledge, this is the first report of the purification and characterization of a lipase from marine B. cereus HSS isolated from the Mediterranean Sea.

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2001년도 10주년 기념 국제학술 심포지움 및 추계학술대회
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• pp.95-95
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• 2001

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2001년도 10주년 기념 국제학술 심포지움 및 추계학술대회
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• pp.96-96
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• 2001

• 한국미생물·생명공학회지
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• 제21권5호
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• pp.446-452
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• 1993

The cholesterol oxidase produced from Bacillus sphaericus was purified and characterized. Through a series of purification procedures including DEAE-Toyoperal 650C, Sephadex G-200 and DEAE-Sephadex A-50 column chromatography, the purified enzyme was shown to have a specific activity of 0.179 units/mg protein having 31.8 fold purification and final yield of 12%. The molecular weight of the enzyme was estimated to be 47kDa and 47.tkDa by Sephadex G-200 chromatography and SDS-PAGE. The optimum temperature and pH for the enzyme were 30C and 6.0, respectively. The activity of the purified cholesterol oxidase was inhibited by Fe2+ and Hg+.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVII)
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• pp.566-569
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• 2005

한국산 개비자나무로부터 새로운 개념의 homoharringtonine 분리 및 정제 공정을 개발하였다. 메탄올을 사용한 4회 반복 추출에 의해 biomass로부터 대부분(>99%)의 homoharringtonine을 회수 할 수 있었다. 흡착 공정에서는 활성 백토(active clay)를 사용하여 추출물에 포함되어 있는 식물유래 타르, 왁스 성분을 효과적으로 제거하였다. Silica gel low-pressure chromatography공정을 통해서 순도 52% 이상의 homoharringtonine을 얻었으며, HPLC 공정을 통해 고순도 및 고수율의 homharringtonine을 정제할 수 있었다. 정제된 homoharringtonine의 분자량 및 구조분석을 수행한 결과 표준물질(Homharringtonine)과 동일 물질임을 확인할 수 있었다.

• 한국동물학회:학술대회논문집
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• 한국동물학회 2000년도 한국생물과학협회 학술발표대회
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• pp.218.1-218
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• 2000

No Abstract, See Full Text

• Bulletin of the Korean Chemical Society
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• 제18권6호
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• pp.648-653
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• 1997

Acetolactate synthase was purified from Escherichia coli MF2000/pTATX containing Arabidopsis thaliana acetolactate synthase gene. Purification steps included DEAE cellulose ion exchange column chromatography, phenyl sepharose hydrophobic column chromatography, hydroxylapatite affinity column chromatography, and Mono-Q HPLC. Molecular weight was estimated to be ∼65 KDa and purification fold was 109 times. The enzyme showed a pH optimum of 7 and the $K_M$ value was 5.9 mM. The purified enzyme was not inhibited by any of the end products, valine, leucine, and isoleucine.

• BMB Reports
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• 제30권3호
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• pp.222-228
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• 1997

Protein phosphatase 2C (PP2C) is one of the four major serine/threonine phosphatases which is dependent on $Mg^{2+}$ for its activity. PP2C was purified from rat liver cytosol and its characteristics were investigated. The substrate employed for routine assay was $[^{32}P]casein$ phosphorylated by PKA. The purification process involved DEAE chromatography, ammonium sulfate fractionation, phenyl sepharose chromatography, sephacryl 5-200 gel filtration, and histone agarose chromatography. The SDS-PAGE of PP2C showed one major single protein band at a position corresponding to a molecular mass of 43 kd and the purification fold was 637. The enzyme showed a pH optimum of 8 and $K_M$ value was $1.9\;{\mu}M$. However, when the substrate was changed to $[^{32}P]histone$, the pH optimum was shifted to 7 and $K_M$ value was $2.3\;{\mu}M.\;Mg^{2+}$ was essential to the enzyme activity and okadaic acid did not exert any inhibitory effect on the enzyme. To examine residue in the active site of PP2C effects of some protein-modifying reagents were tested.

• 한국미생물·생명공학회지
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• 제20권4호
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• pp.401-408
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• 1992

Cholesterol oxidase를 생산하는 균주를 토양으로 분리하고 이를 배양하여 효소를 생산한 후 정제하여 그 특성을 조사하였다. 본 효소는 CH2 concentrator에 의한 농축, DEAE-cellulose chromatography, Superose 12 column FPLC로 정제하였고, 비활성이 약 31배나 증가하였다. 이 효소는 $50^{\circ}C$, pH 6.0에서 최대 활성을 나타냈고 30-$45^{\circ}C$ 범위에서는 안정하였다. pH에 대한 안정성은 pH 6.0-11.0까지 광범위한 안정성을 보였으며, Km 값은 cholesterol에 대해서 $3.65{\times}10^{-3}$M이며 분자량은 59,500 dalton으로 추정 된다. 또한 $Ca^{2+}$, $Ba^{2+}$, $Fe^{2+}$, Brij 35에 의해서는 효소의 활성이 저해되지 않았지만, $Hg^{2+}$, $Ag^{2+}$ 및 SDS에 의해서는 저해되는 것으로 나타났다.