• BMB Reports
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• v.41 no.3
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• pp.254-258
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• 2008

Lipase was purified from squid (Todarodes pacificus) liver in an attempt to investigate the possibility of applying the enzyme for biotechnological applications. Crude extract of squid liver was initially fractionated by the batch type ion exchange chromatography. The fraction containing lipase activity was further purified with an octyl-Sepharose column. Finally, lipase was purified by eluting active protein from a non-dissociating polyacrylamide gel after zymographic analysis. Molecular weight of the purified enzyme was determined to be 27 kDa by SDS-polyacrylamide gel electrophoresis. The enzyme showed the highest activity at a temperature range of $35-40^{\circ}C$ and at pH 8.0. The activity was almost completely inhibited at 1 mM concentration of $Hg^{2+}$ or $Cu^{2+}$ ion. Partial amino acid sequence of the enzyme was also determined.

• Journal of Microbiology and Biotechnology
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• v.10 no.2
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• pp.187-194
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• 2000

An actinomycetes strain, T-2, which produces transglutaminase (EC 2.3.2.13), was isolated from soil and identified as belonging to the Actinomadura sp., based on taxonomc studies. The conditions for the transglutaminase production and its enzymatic properties were investigated. The optimum components for the transglutaminase production were 2% glucose, 1% polypeptone and soytone, and 0.1% MnCl2. The optimum pH and temperature of the enzyme reaction were pH 8.0 and $45^{\circ}C$, respectively. The enzyme was stable within the pH range of 5.0-9.0 and $30^{\circ}C-45^{\circ}C$. The novel enzyme required no calcium ions for its activity. This enzyme polymerized various proteins such as casien, soy protein, hemoglobin, egg white, gelatin, and soybean milk.

• Mycobiology
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• v.32 no.2
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• pp.74-78
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• 2004

An alkaline protease produced by Aspergillus niger C-15 was purified and characterized. The enzyme was purified 19.41-fold with a specific activity of 74150 U/mg and a recovery of 34.4% by gel filtration and ion exchange chromatography. The molecular weight of the enzyme was estimated to be 34 kDa. The optimum pH and temperature for the protease activity were pH 8.0 and $60^{\circ}C$, respectively. The enzyme activity inhibited by EDTA suggests that the preparation contains a metalloprotease. The enzyme activity of the metalloprotease was completely inhibited by 5 mM $HgCl_2$ and $FeCl_3$, while partially inhibited by $CuSO_4$, and $MnCl_2$. When polyols such as glycerol, mannitol, sorbitol and xylitol, were added to the reaction medium, most polyols tested enhanced protease activity. Especially, glycerol showed the highest effect. The alkaline metalloprotease was stable at high temperature and retained more than 90% of the initial activity at $60^{\circ}C$ and 86.4% under addition of glycerol.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.6
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• pp.728-735
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• 1995

The peptidyl prolyl cis-trans isomerase(PPlase, EC 5.2.2.8) from Bacillus stearothermophilus SIC1 was extracted from the cells treated with by lysozyme. PPlase was purified from the cell extracts by heat treatment, ammonium sulfate precipitation, ion exchange chromatography and finally gel filtration (FPLC). The purity of purified the enzyme after Superose 12 column chromatography was examined by sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE). The molecular weight of the purified PPlase was estimated as 18,000 by SDS-PAGE. The 39 amino acid residues from the N-terminus were determined by the protein sequencer. The enzyme showed the optimum pH at 8.0 and was stable at the range of pH 7.0 to 8.0. The enzyme was considerably stable after heat treatment at $60^{\circ}C$ for 30 minutes, and the enzyme was quite stable up to $65^{\circ}C$. The presence of the PPlase in the refolding solution accelerated the isomerization rate of the assay peptide.

• Journal of Microbiology and Biotechnology
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• v.9 no.6
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• pp.861-869
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• 1999

An extracellular protease was purified to homogeneity from the culture supernatant of psychrotrophic bacteria Bacillus sp. JH 108 using procedures including ammonium sulfate fractionation, anion exchange chromatography, gel filtration chromatography, and cation exchange chromatography. The enzyme exhibited a molecular weight of 36 kDa, an optimum pH of 8 to 9, and optimum temperature of $60^{\circ}C$. The enzyme preferentially hydrolyzed leucine at the N-terminus of peptides and thus can be classified as an aminopeptidase. It was strongly inhibited by metal chelating agents such as EDTA and l, l0-phenanthroline. The activity lost by EDTA was restored with $Zn^{2+}{\;}or{\;}Co^{2+}$. These divalent cations also stimulated the native enzyme. This suggests that the enzyme is a metalloprotease acting as a leucine aminopeptidase.

• The Korean Journal of Food And Nutrition
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• v.5 no.2
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• pp.144-149
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• 1992

Invertase was extracted from Korean ginseng(Panax ginseng C. A. Meyer) leaf with deionized water, and then prepared by ammonium sulfate(0.4~0.6 Sat.) fractionation, the enzymological properties of the invertase were investigated, and the results obtained were as follows. The optimum pH and temperature of the enzyme were pH 6.0 and 4$0^{\circ}C$ respectively. The enzyme was stable in the pH range of pH 6.0 to 8.0, and at the temperature below 4$0^{\circ}C$. The enzyme was inactivated completely by the treatment with some proteases(pepsin, trypsin, papain and ficin) and protein denaturants(8M urea and 6M guanidine-HCI), but not with glycosidases (a-amylase, $\beta$-amylase and glucoamylase). The enzyme catalyzed specifically the hydrolization of the $\beta$-fructofuranosides such as sucrose and inulin.

• Journal of Microbiology
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• v.34 no.1
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• pp.82-89
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• 1996

Purine nucleoside phosphorylase (PNP) was purified in Micrococcus luteus (M. luteus) using streptomycin sulfate and amomonium sulfate fractionation, three times by a Sephadex G-100 gel filtration and a DEAE-Sephadex A-50 ion exchange chromatography. The enzyme was purified 72 folds with a 11% recovery and showed a single band in a nondenaturing gel electrophoresis. The M. W. of PNP turned out to be 1.35 * 10$^{5}$ delton in G-150 gel filtration chromatography. The stability of the enzyme was increased by treatment with both substrates, MgCI$_{2}$ or CaCI$_{2}$, but not significantly kcal/mol. M. luteus PNP catalyzed the phosphorolysis of inosine, deoxyinosine, guanosine and deoxyguanosine with the Km value of 1.5 * 10$^{-3}$ M, 3.0 * 10$^{-3}$ M, 5.0 * 10$^{-4}$ M, respectively. The enzyme was reacted with adenosine, 1-methylnosine and 1-methylguanosine as substrates, which were shown to be poor substrates for mammalian enzyme.

• Journal of Microbiology and Biotechnology
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• v.3 no.3
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• pp.188-193
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• 1993

Superoxide dismutase (SOD) was purified from Pseudomonas polycolor to an electrophoretically homogeneous state and partially characterized. SOD was purified by ammonium sulfate fractionation, column chromatography on DEAE-Sephadex A-50, phenyl-Toyopearl 650 M, and gel filtration on Sephadex G-100. The molecular weight and subunit molecular weight of the purified enzyme were estimated to be 40, 000 and 20, 000, respectively. The purified enzyme remained stable at pH 9.0~11.0, $25^{\circ}C$ for 40 hr, but rapidly became inactive below 9.0. SOD was stable up to $45^{\circ}C$ at pH 9.0 with about 80% relative activity, but rapidly became inactive at temperature above that. The enzyme was insensitive to cyanide and fluoride, and sensitive to hydrogen peroxide and azide. The results suggest that the enzyme be an iron-containing SOD.

• The Korean Journal of Food And Nutrition
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• v.7 no.2
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• pp.119-123
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• 1994

Aspergillus sp. BY-54 which produced a strong dextran hydrolyzing enzyme was isolated from soil. Using this strain, the optimal cultural conditions, enzyme purification and characterization were studied. The results are as follows : The optimal concentration of dextran as carbon source was l%. and the optimum temperature and the initial pH for enzyme production was 3$0^{\circ}C$, and 7.0, respectively. Dextranase was purified by DEAE-cellulose column chromatography with a linear gradient increase in NaCl. Km value of dextranase was 0.222%, and several glucans containing various types of glucosidic linkages such as DEAE-sephadex, CM-sephadex and sephadex G-100 were almost digested to a large extent with this dextranase. The enzyme was strongly inhibited by sodium fluoride, KMnO4 and p-CMB, while KCN caused 20% of activation.

• Microbiology and Biotechnology Letters
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• v.21 no.6
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• pp.588-593
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• 1993

Xylanase(1, 4-beta-D-xylan xylanohydrolase` EC 3.2.1.8) II was purified from Penicillium verruculosum by using the techniques of two anion exchange chromatographies, and gel filtration. The molecular weight of this enzyme was about 22, 000 as determined by SDS-electrophoresis. The enzyme showed hydropytic activity toward xylan but did not catalyze hydrolysis of Rho-nitrophenyl-beta-D-xylopyranoside, Rho-nitrophenyl-beta-D-glucopyranoside, Rho-nitrophenyl-beta-D-cellobiopyranoside, and celluloses such as Avicel, cotton, filter paper, carboxymethylcellulose.