• Journal of Microbiology and Biotechnology
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• v.6 no.3
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• pp.151-161
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• 1996

• Microbiology and Biotechnology Letters
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• v.50 no.1
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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.

• Proceedings of the Korean Society of Life Science Conference
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• 2001.09a
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• pp.95-95
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• 2001

• Proceedings of the Korean Society of Life Science Conference
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• 2001.09a
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• pp.96-96
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• 2001

• Microbiology and Biotechnology Letters
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• v.21 no.5
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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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• 2005.10a
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• pp.566-569
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• 2005

A novel purification method was developed for producing homoharringtonine from Cephalotaxus koreana, to guarantee high purity and yield. Our simple, efficient procedure for isolating and purifying homoharringtonine from C. koreanabiomass consisted of solvent extraction, synthetic adsorbent treatment, low-pressure chromatography, followed by high performance liquid chromatography (HPLC). The use of active clay treatment and silica gel low-pressure chromatography in the pre-purification process allowed for the rapid, efficient separation of homoharringtonine from interfering compounds and dramatically increased the yield and purity of crude homoharringtonine for high-performance liquid chromatography (HPLC) purification steps compared with alternative processes. Homoharringtonine could be obtained simply with high yield and purity from biomass using this purification method, while minimizing solvent use and the scale and complexity of HPLC operations for homoharringtonine purification. Purified homoharringtonine was identified and characterized.

• Proceedings of the Zoological Society Korea Conference
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• 2000.10a
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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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• v.18 no.6
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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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• v.30 no.3
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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.

• Microbiology and Biotechnology Letters
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• v.20 no.4
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• pp.401-408
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• 1992

The extracellular cholesterol oxidase produced from a soil microorganism HSL613 was purified and partially characterized. Through a series of purification procedures including concentration with CH2 concentrator, DEAE-cellulose column chromatography and gel filtration on Superose12, the purified enzyme was shown to have a specific activity of 108 units/mg protein giving 30.8-fold purification and final yield of 66%. The molecular weight of the enzyme was estimated to be 59,500 daltons by SDS-PAGE. The optimum temperature and pH for this enzyme were $50^{\circ}C$ and 6.0, respectively. The activity of the purified cholesterol oxidase was inhibited by $Ag^{2+}$, $Hg^{2+}$ and SDS.