• Microbiology and Biotechnology Letters
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• v.23 no.4
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• pp.411-415
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• 1995

The dextranase (EC 3.2.1.11) produced by Aspergillus ustus GR-98 was purified by the following sequential methods; salting-out and dialysis, gel filtration on BIO-GEL P-100, ion exchange chromatography on DEAH-cellulose, affinity chromatography on hydroxyapatite, and preparative electrophoresis. Three active fractions, dextranases 1, 11 and 111, were isolated in electrophoretically pure states, and specific activities of the dextranases were 1,276, 1,154 and 1,125 units/mg, the degrees of yield were 9.0, 3.6 and 2.2%, having 145, 131.1 and 127.8 times as those of culture filtrate in degree of purification, respectively. The enzyme purity was confirmed by the PAGE, SDS-PAGE and get permeation-HPLC.

• Korean Journal of Food Science and Technology
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• v.34 no.3
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• pp.425-430
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• 2002

Physicochemical properties of chicken feet gelatin produced under acidic and alkaline conditions were investigated. Amino acid content of chicken feet gelatin was different from that of commercial gelatin due to the differences in raw materials and production process. Yield and hardness of chicken feet gelatin reached maximum at 24 h under acidic condition and at 1 week under alkaline condition, respectively. As the soaking period increased, viscosity and clarity increased under acidic condition, while decreased under alkaline condition. Color of the acid-treated chicken feet gelatin gel was more desirable than that of the alkali-treated on based upon L, a, b values. From gel permeation chromatography of the chicken feet gelatin, 12 subunits were detected. The amount of high molecular weight subunits, which is related to viscosity and hardness, of the alkali-treated chicken feet gelatin was twice as much as that of the acid-treated one.

• Journal of the Korean Wood Science and Technology
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• v.33 no.6 s.134
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• pp.79-86
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• 2005

Aspen wood (Populus tremuloides, L.) was biotreated with Ceriporiopsis subvermispora for 1, 2, 4, and 6 weeks to observe the physical/chemical modification of wood components. Milled wood lignins (MWLs) isolated from each decayed wood were analyzed by gel permeation chromatography (GPC) and nitrobenzene oxidation (NBO). As fungal treatment was progressed, lignin contents continuously decreased up to 20% after 6-week treatment. The lignin polymer could be fragmented to low-molecular phenolics, which make an enhancement of alkali solubility. Holocellulose contents were not affected severely during the period of fungal treatment, only reduction of 5~6% compared to the control. Xylose contents were decreased gradually from 23.4% to 18% after 6 weeks, whereas alpha-cellulose remained almost unchanged. Gel permeation chromatography (GPC) indicates that molecular weight of lignin undergoes a slight decrement for 4 weeks of fungal treatment. Nitrobenzene oxidation revealed that total yield of NBO products of lignins were lowered ca 20% after fungal treatment. Sum of syringaldehyde and syringic acid are remarkably decreased. However, increment of sum of vanillin and vanillic acid was surprisingly observed. These results work as indirect evidence that a specific lignolytic reaction, maybe selective demethoxylaytion of S-lignin, can occur during fungal treatment of aspen wood by C. subvermispora.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.9
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• pp.1232-1236
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• 2006

Crude polysaccharide fractions of commercially available grape wines (red wine, white wine and wild grape wine) were prepared by evaporation and ethanol precipitation to confirm and identify anti complementary polysaccharides in the wines. When these fractions were evaluated for their anti complementary activity, crude polysaccharide fractions of red wine (RW-0) and wild grape wine (WGW-0) showed higher anti-complementary activities than those of white wine (WW-0). RW-0 and WW-0 were further fractionated into RW-1, WW-1 as high-molecular fractions, and RW-2, WW-2 as low-molecular fractions through gel permeation column chromatography on Sephadex G-75. RW-1 had the most potent activity with the highest carbohydrate content (91.3%). Anti-complementary activity of red wine was higher than that of white wine, suggesting that active polysaccharides such as pectin and hemicellulose are mainly distributed in the grape skin which is removed during white wine making. In addition, high molecular fractions, RW-1 and WW-1 with high contents of carbohydrate and high yields showed higher activities than those of low molecular fractions, RW-2 and WW-2.

• International Journal of Industrial Entomology and Biomaterials
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• v.2 no.1
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• pp.55-59
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• 2001

The vitellin of the red flour beetled Tribolium castaneum Herbst was purified and characterized. The vitellin of T. castaneum was purified by the FPLC techniques, anion exchange chromatography and gel permeation chromatography. In native-polyacrylamide gel electrophoresis, vitellin of T. castaneum was detected as a single band. This native vitellin has molecular weight of 440 kDa. The vitellin of T. castaneum is composed of three polypeptides, designated Vnl (178 kDa), Vn2 (168 kDa) and Vn3 (52 kDa) in SDS-polyacrylamide gel electrophoresis. Three subunits of vitellin were presented in the female adult hemolymph and egg extracts, but not observed in the male. These three polypeptides gradually decreased during embryogenesis. Polyclonal antiserum raised against purified vitellin reacted with the three polypeptides, Vnl, Vn2 and Vn3. Antisera raised against Vn1 and Vn2 cross-reacted with the two large subunits, Vnl and Vn2, respectively. Another subunits Vn3, however, was not cross-reacted with these two antisera. Also, antiserum raised against Vn3 did not cross-react with the Vn1 and Vn2.

• Korean Journal of Microbiology
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• v.44 no.2
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• pp.116-121
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• 2008

In my search of microbial source of novel enzymes, a marine actinomycetes, A1460, producing haloperoxidase was isolated from macroalgae from south sea, Korea and studied for physiological and biochemical properties. The haloperoxidation reaction was followed by the bromination of phenol red in the presence of hydrogen peroxide and potassium bromide. The haloperoxidase was partially purified from the cell extract with $35\sim75%$ ammonium sulfate precipitation, High-Q anion exchange chromatography, gel filtration chromatography, hydroxyapetite chromatography and hydrophobic interaction chromatography to a yield of 42% and purification fold of 70. This enzyme showed relatively high heat stability without losing 50% of activity after 1 hr incubation at $60^{\circ}C$. The highest activity was found at $45^{\circ}C$, and the optimal pH was about pH 7, but higher stability was observed at pH 8. Azide and cyanide ion showed strong inhibition at less than 1 $\mu M$ level suggesting that the enzyme was Fe ion dependent haloperoxidase.

• Food Science of Animal Resources
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• v.40 no.1
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• pp.87-95
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• 2020

In this study, we separated and purified lipase inhibitory peptide from fermented milk by Lactobacillus plantarum Q180 with the aim of developing a new functional anti-lipase activity yogurt product. L. plantarum 180 was inoculated into 10% reconstituted skimmed milk and incubated at 37℃ until the pH of the culture reached pH 4.4. The lipase activity was measured using porcine pancreatic lipase. The lipase inhibitory peptides were gradually isolated by ultrafiltration, reversed phase column chromatography (RPC), reversed phase high-performance liquid chromatography (RP-HPLC), and gel permeation high-performance liquid chromatography (GP-HPLC) from the fermented milk by L. plantarum Q180. An ODS-AQ column was used for the RPC, a Vydac C18 column for the RP-HPLC, and a Superdex Peptide HR column for the GP-HPLC. The peptide was composed of Asp, Thr, Ile, Ser, Ala, and Gln, and the anti-lipase activity (IC₅₀) was 2,817 ㎍/mL.

• Mycobiology
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• v.48 no.1
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• pp.51-57
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• 2020

A polysaccharide (LVP) was purified from fruiting body of Lentinus velutinus by ethanol precipitation fractionation and DEAE and Sephadex G-100 column chromatography. The yield of purified polysaccharide was 0.025%. Molecular characteristics of LVP were determined by gel permeation chromatography, FT-IR spectroscopy, and thin-layer chromatography. Our results revealed that LVP is a polysaccharide composed of only glucose units, and has a molecular weight of 336 kDa. Biological activity assays indicated that LVP exhibits both cytotoxic and antioxidant activity. LVP showed specific cytotoxicity against cancer cells (HeLa and HepG2 cells), and alterations in cancer cell morphology were found after LVP treatment.

• Preventive Nutrition and Food Science
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• v.9 no.1
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• pp.95-97
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• 2004

An angiotensin converting enzyme (ACE) inhibitory substance was isolated and purified from Lycium chinense Miller. A crude water extract of Lycium chinense Miller was prepared by adding it to water shaking at $25^{\circ}C$ for 1 hr, followed by centrifugation at 8000 ${\times}$ g for 30 min. The crude extract was then filtered using YM-3 and YM-1 membranes. An ACE inhibitor was isolated using consecutive chromatographic methods including: ion exchange chromatography, gel permeation chromatography, and FPLC. The inhibitor was identified to have a molecular mass of 862 daltons by mass spectrometry.

• Preventive Nutrition and Food Science
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• v.8 no.1
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• pp.66-69
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• 2003

An angiotensin converting enzyme (ACE) inhibitory peptide was isolated and purified from the hydrolysates of duck meat protein. Duck meat protein was hydrolyzed using trypsin at 37$^{\circ}C$ for 2 hrs. An ACE inhibitory peptide was purified using membrane filtration, anion exchange chromatography, gel permeation chromatography, fast protein liquid chromatography, normal phase HPLC. The purified inhibitory peptide was identified to be a tetrapeptide, Glu-Asp-Leu-Glu having $IC_{50}$/ value of 85.9 $\mu$M.