• Journal of Ginseng Research
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• v.37 no.1
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• pp.117-123
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• 2013

Polyphenol oxidase (PPO) was purified from fresh ginseng roots using acetone precipitation, carboxymethyl (CM)-Sepharose chromatography, and phenyl-Sepharose chromatography. Two isoenzymes (PPO 1 and PPO 2) were separated using an ion-exchange column with CM-Sepharose. PPO 1 was purified up to 13.2-fold with a 22.6% yield. PPO 2 bound to CM-Sepharose, eluted with NaCl, and was purified up to 22.5-fold with a 17.4% yield. PPO 2 was further chromatographed on phenyl-Sepharose. The molecular weight of the purified PPO 2 from fresh ginseng was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and was about 40 kDa. The optimum temperature and pH were $20^{\circ}C$ and 7.0, respectively, using catechol as a substrate. Pyrogallol showed the highest substrate specificity. The effect of a PPO inhibitor showed that its activity increased slightly in the presence of a low concentration of citric acid. High concentrations of acidic compounds and sulfite agents significantly inhibited purified ginseng PPO 2.

• Korean Journal of Microbiology
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• v.45 no.3
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• pp.257-262
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• 2009

Carboxymethyl celluase (cellulase) was purified from cell-free extract of the recombinant Escherichia coli carrying a Bacillus licheniformis WL-12 cellulase gene by DEAE-Sepharose and phenyl-Sepharose column chromatography with specific activity of 163 U/mg protein. The molecular mass of the purified enzyme was estimated to be approximately 49.5 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzyme had a pH optimum at 5.5 and a temperature optimum at $55^{\circ}C$. The activity of the enzyme was completely inhibited by SDS (5 mM), and slightly enhanced by $Cu^{2+}$ (5 mM). The cellulase was active on CMC, konjac, barely glucan and lichenan, while it did not exhibit activity towards xylan, locust bean gum, and p-nitrophenyl-$\beta$-glucopyranoside. The predominant products resulting from the cellulase hydrolysis were cellobiose and cellotriose for cellooligosaccharides including cellotriose, cellotetraose and cellopentaose. The enzyme could hydrolyze cellooligosaccharides larger than cellobiose.

• Korean Journal of Agricultural Science
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• v.24 no.2
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• pp.275-282
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• 1997

The prcx.iuction of extracellular 1,4-${\beta}$-glucanase by Cellulomonas sp. CS1-1 on microcrystalline cellulose, sigmacell was maximal after 5-day cultivation as 280 units/mL, which was three times higher than the level produced on carboxymethyl cellulose. A carboxymethyl cellulase containing the carbohydrate of 8.2% was purified from the culture filtrate by successive procedures of column chromatographies. Purification factor was calculated as 22-folds with the specific carboxymethyl cellulase activity of 31.9 units/mg. The molecular weight and isoelectric point of the purified enzyme were 54,000 and pI 5.4, respectively. The optimal pH and temperature were 6.0 and $45^{\circ}C$, and the enzyme was stable between pH 6.5 and 7.5 and below $50^{\circ}C$. The estimated Km and Vmax were 10 mg/mL and $6.25{\mu}mol/min$ for carboxymethyl cellulose and 30.3 mg/mL and $2.85{\mu}mol/min$ for sigmacell, respectively. The enzyme was partially inhibited by $Ag^+$, $Zn^{+{+}}$, $Fe^{+{+}}$ and EDTA, while completely inhibited by $Cd^{+{+}}$ and $Hg^{+{+}}$ at 1 mM concentration.

• Current Research on Agriculture and Life Sciences
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• v.3
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• pp.166-173
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• 1985

Several enzyme immobilization methods has been compared for immobilization of pepsin. Carboxymethyl cellulose and diethylaminoethyl cellulose were activated with Hcl and with NaOH, and were used for immobilization of pepsin. Sepharose-4B was activated cyanogen bromide, and was used for immobilization of pepsin. Porous glass beads were derivatized with 3-aminopropyitrlethoxysilane and with succinicanhydride, and were used for immobilization of pepsin. The results abtained were summarized as follow, 1. 10 mg/gr. dry bead and 15mg/gr. dry bead of pepsin were absorbed to CM-cellulose and DEAE-cellulose, 20 mg/gr. dry bead and 27 mg/gr. dry bead were coupled to CM-cellulose and DEAE-cellulose with glutaraldehyde respectively. Enzyme yields were 22% and 24% of soluble pepsin. 2. 16 mg/gr. dry bead of pepsin was attached to cyanogen bromide activated sepharose-4B, 19mg/gr. dry bead was cross linked to the activated bead with glutaraldehyde. Immobilized enzyme activity was 23% of soluble pepsin. 3. 40 mg/gr. dry bead of pepsin was conjugated to the derivatized glass beads. Immobilized enzyme activity was 45% of soluble pepsin.

• Korean Journal of Agricultural Science
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• v.39 no.2
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• pp.255-261
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• 2012

A bacterium AB-55, isolated from waste mushroom bed of Agaricus bisporus in Sukseong-myeon, Buyeo-gun, Chungcheongnam-do, Korea, was screened onto xylan agar congo-red plate by the xylanolysis method and was used to produce an xylanase in shaker buffle flask cultures containing oat spelt xylans. The phylogenetic analysis using 16S rRNA gene sequence data showed that the strain AB-55 had the highest homology (99.0%) with Bacillus subtilis and it was named as Bacillus subtilis AB-55. A xylanase was purified by ammonium sulfate precipitation (50~80%), gel filtration on sephacryl S-300, and ion exchange chromatography on DEAE sepharose FF. The molecular weight of the xylanase was estimated as 44 kDa by SDS-PAGE. Optimal pH and temperature for the xylanase activity was pH 7 and $50^{\circ}C$, respectively. N-terminal amino acid sequence of the enzyme was identified as Ser-Ala-Val-Lys-His-Gly-Ala-Ile-Val-Phe. The substrate specificity of the enzyme exhibited that it hydrolyzed efficiently oat spelt xylan as well as beechwood xylan, but showed no activity against Avicel and carboxymethyl clellulose (CMC). The enzyme activity was enhanced by $Fe^{2+}$ and $Mn^{2+}$ whereas was entirely inhibited by $Hg^+$.