• Journal of Microbiology and Biotechnology
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• v.18 no.4
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• pp.670-675
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• 2008

A laccase was isolated from the culture filtrate of the basidiomycete Fomitella fraxinea. The enzyme was purified to electrophoretical homogeneity using ammonium sulfate precipitation, anion-exchange chromatography, and gel-filtration chromatography. The enzyme was identified as a monomeric protein with a molecular mass of 47 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and gel-filtration chromatography, and had an isoelectric point of 3.8. The N-terminal amino acid sequence for the enzyme was ATXSNXKTLAAD, which had a very low similarity to the sequences previously reported for laccases from other basidiomycetes. The optimum pH and temperature for 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) were 3.0 and $70^{\circ}C$, respectively. The enzyme also showed a much higher level of specific activity for ABTS and 2,6-dimethoxyphenol (DMP), where the $K_m$ values of the enzyme for ABTS and 2,6-DMP were 270 and $426{\mu}M$, respectively, and the $V_{max}$ values were 876 and $433.3{\mu}M/min$, respectively. The laccase activity was completely inhibited by L-cysteine, dithiothreitol (DTT), and sodium azide, significantly inhibited by $Ni^+,\;Mn^{2+}$, and $Ba^{2+}$, and slightly stimulated by $K^+$ and $Ca^{2+}$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.8
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• pp.4106-4110
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• 2013

Apolipophorin-III (apoLp-III) was isolated and purified from the last larval hemolymph of Galleria mellonella by the KBr gradient ultracentrifugation and gel chromatography (Sephadex G-100). In this paper, we examined that apoLp-III is taken up into the last larval fat bodies in Galleria mellonella. The last larval fat body tissues were incubated at room temperature for 30 min with fluorescein isothiocyanate (FITC)-labeled apoLp-III (FITC-apoLp-III). Fluorescein microscopy and sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE) revealed that the last larval fat body tissues internalize FITC-apoLp-III. The results show that the apoLp-III is taken up by the last larval fat body.

• Korean Journal of Food Science and Technology
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• v.20 no.1
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• pp.90-94
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• 1988

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunodiffusion method were used for the species differentiation of yeasts, Saccharomyces cerevisiae, Candida utils, Candida tropicalis, and Kleuyveromyces fragilis. Comparing the electrophoretic patterns of soluble and membrane proteins, Saccharomyces cereνisiae was similar to Candida utilis but was different from Candida tropicalis and Kleuyveromyces fragilis. In immunochemical properties of soluble proteins, Saccharomyces cerevisiae was almost identical with Candido utilis. However, Saccharomyces cerevisiae or Candida utilis was quite different from Candida tropicalis and Kleuyveromyces fragilis in their immunoreactivities. In immunochemical properties of membrane proteins, almost the same results were obtained irrespective of four yeast species. By using SDS-PAGE and immunodiffusion methods, Saccharomyces cerevisiae and Candida utilis were difficult to differentiate but both species were easily differentiated from Candida tropicalis and Kleuyveromyces fragilis.

• Journal of Plant Biology
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• v.38 no.3
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• pp.251-258
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• 1995

The soluble acid invertase ($\beta$-D-fructofuranoside fructohydrolase, EC 3.2.1.26) was isolated and characterized from the hypocotyls of mung bean (Phaseolus radiatus L.). The enzyme was purified to apparent homogeneity by consecutive step using diethylaminoethyl (DEAE)-cellulose anion exchange, Concanavalin (Con) A affinity and Sephacryl S-300 chromatography. The overall purification was about 148-fold with a yield of about 15%. The finally purified enzyme exhibited a specific activity of about 139 $\mu$mol of glucose produced mg-1 protein min-1 at pH 5.0 and appeared to be a single protein by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and nondenaturing PAGE. The enzyme had the native molecular weight of 70 kD and subunit molecular weight of 70 kD as estimated by Sephadex G-200 chromatography and SDS-PAGE, respectively, suggesting that the enzyme was composed of a monomeric protein. On the other hand, the enzyme appeared to be a glycoprotein containing N-linked high mannose oligosaccharide chain on the basis of its ability to bind to the immobilized C on A. The enzyme had a Km for sucrose of 1.8 mM at pH 5.0 and maximum activity around pH 5.0. The enzyme showed highest enzyme activity with sucrose as substrate, but the activity was slightly measured with raffinose and cellobise. No activity was measured with maltose and lactose. These results indicate the soluble acid invertase is a $\beta$-fructofuranosidase.

• KSBB Journal
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• v.5 no.1
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• pp.19-23
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• 1990

A cholesterol esterase-producing microorganism, strain CES 506, isolated from soil was identified as Aeromonas sp. This strain produce about 0.023 units of cholesterol esterase per ml of culture broth. The cholesterol esterase produced by this strain was purified, 370 fold to homogeneity in an overall yield of 24% from culture broth. The apparent molecular weight was 64, 000, as estimated by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The enzyme showed a high substrate specificity for cholesterylpalmitate and the Km value for the hydrolysis of cholesterylpalmitate by this enzyme were 0.15mM.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.199-203
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• 2016

Apolipophorin-III (apoLp-III) was isolated and purified from the last larval hemolymph of Galleria mellonella by KBr gradient ultracentrifugation and gel chromatography (Sephadex G-100). After KBr gradient ultracentrifugation, the lipophorin-free fractions were used as the samples for gel chromatography. The purity of the finally purified apoLp-III was confirmed by SDS-PAGE after gel chromatography. In this study, we found that apoLp-III is taken up into the adult testes in Galleria mellonella. The testes were dissected from day-1 or -2 adults in cold Ringer's solution and used for tissue culture. The protein moiety of apoLp-III was labeled with FITC dissolved in dimethyl sulfoxide (DMSO) at room temperature under conditions of continuous stirring for 1 h. The FITC-labeled apoLp-III was purified with a Sephadex G-25 PD-10 column. The tissues of the adult testes were incubated at room temperature for 30 min with fluorescein isothiocyanate (FITC)-labeled apoLp-III. Fluorescein microscopy and sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE) revealed that the adult testis tissues internalize the FITC-labeled apoLp-III. The results showed that apoLp-III is taken up by the adult testes.

• Journal of Applied Biological Chemistry
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• v.55 no.3
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• pp.173-178
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• 2012

Sucrose-glucan glucosyltransferase (Gtf) is an important enzyme involved in the cavity formation process where insoluble glucan is synthesized. In this study, we purified Gtf from Streptcoccus mutans Ingbritt through ammonium sulfate precipitation, Sephadex G-150, CM-Sephadex, and DEAE-Sephadex column chromatographies. A 13-fold of purification was achieved with a total yield of 6.3%. The apparent molecular mass of the enzyme was determined to be 66 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The optimal pH and temperature were established to be 6.0 and $40^{\circ}C$, respectively. The enzyme activity could be inhibited to 22-59% by 1 mM $Hg^{2+}$, $Cu^{2+}$ and $Al^{3+}$, and to 68% by 1 mM EDTA. It was also inhibited 40% by 2 mM xylitol and 35-45% by 0.05% soluble chitosan, glycol chitosan, and glycol chitin. This is the first report to reveal the inhibition effect of chitin derivatives on Gtf activity, which may be further applicable to develop gargles to overcome cavity.

• Journal of Microbiology and Biotechnology
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• v.13 no.1
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• pp.119-124
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• 2003

This study was conducted to evaluate the practical usefulness of the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PACE) fingerprinting of whole cell proteins far the identification of lactic acid bacteria in Kimchi. SDS- PACE of whole cell proteins of the reference strains and lactic acid bacteria isolated from Kimchi yielded differential banding patterns that were highly specific fingerprints, thus making it possible to identify. Identification of the isolates from Kimchi was achieved by comparing the SDS-PAGE fingerprints of isolates to those of reference strains. In addition, the reliability of SDS-PAGE was examined by comparing the results with those of the APL 50 CHL system assay and 16S rRNA gene sequence. SDS-PACE assay showed a different identity to reference strains, while the APL 50 CHL system and 16S rRNA gene sequence could not distinguish a few strains. Therefore, SDS-PAGE of the whole cell proteins is a specific and a reliable method that will be useful for the identification of lactic acid bacteria in Kimchi to the species level, and can be used as an alternative or complementary identification method.

• Fisheries and Aquatic Sciences
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• v.15 no.1
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• pp.9-14
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• 2012

The objectives of this research were to improve the film-forming properties of Channel Catfish Ictalurus punctatus skin gelatin (CSG) by cross-linking with transglutaminase (TG), determine and optimize the TG reaction time, and characterize the mechanical and barrier properties of CSG edible film. Cross-linking of CSG was performed by TG for 0, 10, 20, 30, and 40 min at $50^{\circ}C$, and the reaction was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The color and mechanical and barrier properties of edible films fabricated with CSG cross-linked with TG were characterized. Gelatin yields from the extraction ranged from 18.2% to 23.3%. SDS-PAGE exhibited dark bands at 120 and 250 kDa, indicating successful TG-mediated cross-linking. The color of CSG film was not affected by TG cross-linking. The tensile strength of CSG films cross-linked with TG decreased from 42.59 to 21.73 MPa and the percent elongation increased from 42.92% to 76.96% as reaction times increased from 0 to 40 min. There was no significant difference in water vapor permeability of CSG films.

• Journal of Animal Science and Technology
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• v.63 no.2
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• pp.405-416
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• 2021

The aim of the study was to determine the effect of whole milk powder (WMP) as heterologous proteins on chicken breast emulsion-type sausages. The quality properties of WMP on such chicken breast emulsion-type sausages were investigated by measuring the proximate composition, pH, color, cooking yield, protein solubility, and by applying other methods, such as texture profile analysis (TPA), microphotograph, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and electronic nose. The crude fat, protein, and ash contents of 15% WMP samples were significantly higher than the control samples (p < 0.05). The redness of the cooked samples significantly increased with an increase in the WMP contents (p < 0.05). The cooking yield of WMP treated samples was significantly higher than the control sample (p < 0.05). Additionally, the hardness, gumminess, and chewiness of WMP treated samples were significantly higher than the control sample (p < 0.05). The sarcoplasmic and myofibrillar proteins of samples containing 15% WMP were significantly higher than the control samples (p < 0.05). The result of SDS-PAGE showed that the C protein, sarcoplasmic protein, actin, and tropomyosin increased with an increase in the WMP contents. The principal component analysis plot of WMP-treated samples was clearly different from that of the control samples. Based on these results, it was predicted that WMP could be useful as heterologous protein on emulsion-type sausage.