• BMB Reports
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• v.30 no.6
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• pp.438-442
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• 1997

${\gamma}-Glutamylamine$ cyclotransferase was purified to homogeneity from soybean (Glycine max) seeds. To our knowledge, it is the first purification of the enzyme from plant origins. The molecular weight of the enzyme estimated by Sephacryl S-300 gel filtration and SDS-PAGE was 27,000, indicating that the enzyme is a monomer. The optimal pH for activity was 8.6. The Km value for ${\gamma}-glutamyldansylcadaverine$ was 11 ${\mu}M$. The enzymatic activity was substantially inhibited by the addition of p-chloromercuribenzoate and partially inhibited by the $Cu^{2+}$ ion. However, neither other modification reagents nor other divalent metal ions affected the enzymatic activity. The comparison between the enzymatic activities of seed extracts treated with cycloheximide and control extracts, and the detection of the same single protein band by western blot analysis at the dormant stage without inhibition with distilled water indicate that ${\gamma}-Glutamylamine$ cyclotransferase is already present at the dormant stage and gradually activated during germination in soybean seeds.

• Journal of Microbiology and Biotechnology
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• v.20 no.12
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• pp.1711-1716
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• 2010

A gene encoding the ${\beta}$-xylosidase/${\alpha}$-arabinofuranosidase (XylC) of Paenibacillus woosongensis was cloned into Escherichia coli. This xylC gene consisted of 1,425 nucleotides, encoding a polypeptide of 474 amino acid residues. The deduced amino acid sequence exhibited an 80% similarity with those of both Clostridium stercorarium ${\beta}$-xylosidase/${\alpha}$-N-arabinosidase and Bacillus cellulosilyticus ${\alpha}$-arabinofuranosidase, belonging to the glycosyl hydrolase family 43. The structural gene was subcloned with a C-terminal His-tag into a pET23a(+) expression vector. The His-tagged XylC, purified from a cell-free extract of a recombinant E. coli BL21(DE3) Codon Plus carrying a xylC gene by affinity chromatography, was active on para-nitrophenyl-${\alpha}$-arabinofuranoside (pNPA) as well as para-nitrophenyl-${\beta}$-xylopyranoside (pNPX). However, the enzymatic activities for the substrates were somewhat incongruously influenced by reaction pHs and temperatures. The enzyme was also affected by various chemicals at different levels. SDS (5 mM) inhibited the enzymatic activity for pNPX, while enhancing the enzymatic activity for pNPA. Enzyme activity was also found to be inhibited by addition of pentose or hexose. The Michaelis constant and maximum velocity of the purified enzyme were determined for hydrolysis of pNPX and pNPA, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.6
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• pp.1013-1016
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• 2004

The inhibitory effect of MRPs (Maillard reaction products) on enzymatic browning of taro was investigated. The MRPs prepared by heating glycine and glucose at 9$0^{\circ}C$ for 7 hr exhibited a strong inhibitory effect on taro polyphenol oxidase (PPO). The maximum inhibitory activity of MRPs against taro PPO was detected toward (＋)-catechin, catechol, 4-methylcatechol followed by L-$\beta$-3,4-dihydroxyphenylalanine (L-DOPA) and pyragallol as a substrate. The MRPs synthesized from fructose and glucose with glycine as a amino acid significantly reduced the taro PPO activity. MRPs prepared by higher glycine or glucose concentration showed stronger inhibition against taro PPO. Increasing reaction time of the glycine and glucose promoted the inhibitory effect of MRPs against the PPO activity of taro, whereas the color formation was gradually increased.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.7
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• pp.953-959
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• 2010

We extracted bioactive materials from Codium fragile by enzymatic hydrolysis using four different proteases (Alcalase, Flavourzyme, Neutrase, and Protamex) and seven different carbohydrases (amyloglucosidase (AMG), Celluclast, Dextrozyme, Maltogenase, Promozyme, Termamyl, and Viscozyme), and evaluated their biological activities such as antioxidant, anti-acetylcholinesterase (AChE), and anti-inflammatory effects. All enzymatic hydrolysates showed good DPPH radical scavenging capacities, in particular, Flavourzyme and Promozyme hydrolysates possessed the highest activity. The two hydrolysates also exhibited strong hydrogen peroxide scavenging activity, $Fe^{2+}$ chelating activity, and reducing power in a dose-dependent manner. Furthermore, the two hydrolysates effectively protected DNA damage induced by hydroxyl radical by measuring the conversion of supercoiled DNA to the open circular DNA. All enzymatic hydrolysates also showed high anti-AChE inhibitory activities in a dose-dependent manner, and did not showed any significant cytotoxicity on RAW264.7 cells (p<0.05). In addition, the enzymatic hydrolysates significantly (p<0.05) inhibited lipopolysaccharide induced-nitric oxide production on RAW264.7 cells. These results suggest that the enzymatic extracts from Codium fragile would be good source as an ingredient of functional foods.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.11
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• pp.1612-1619
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• 2017

Objective: The objective of this study was to optimize ultrasonic-assisted enzymatic hydrolysis conditions, including enzyme-to-substrate (E/S) ratio, pH, and temperature, for producing porcine liver hydrolysates (PLHs) with the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity by using response surface methodology (RSM). Methods: The study used RSM to determine the combination of hydrolysis parameters that maximized the antioxidant activity of our PLHs. Temperature ($40^{\circ}C$, $54^{\circ}C$, and $68^{\circ}C$), pH (8.5, 9.5, and 10.5), and E/S ratio (0.1%, 2.1%, and 4.1%) were selected as the independent variables and analyzed according to the preliminary experiment results, whereas DPPH free radical scavenging activity was selected as the dependent variable. Results: Analysis of variance showed that E/S ratio, pH, and temperature significantly affected the hydrolysis process (p<0.01). The optimal conditions for producing PLHs with the highest scavenging activity were as follows: E/S ratio, 1.4% (v/w); temperature, $55.5^{\circ}C$; and initial pH, 10.15. Under these conditions, the degree of hydrolysis, DPPH free radical scavenging activity, ferrous ion chelating ability, and reducing power of PLHs were 24.12%, 79%, 98.18%, and 0.601 absorbance unit, respectively. The molecular weight of most PLHs produced under these optimal conditions was less than 5,400 Da and contained 45.7% hydrophobic amino acids. Conclusion: Ultrasonic-assisted enzymatic hydrolysis can be applied to obtain favorable antioxidant hydrolysates from porcine liver with potential applications in food products for preventing lipid oxidation.

• Natural Product Sciences
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• v.11 no.3
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• pp.155-159
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• 2005

The aqueous extract of Coscinium fenestratum was studied for its antioxidant status in STZ-nicotinamide induced type 2 diabetic rats at two dose levels of 250 mg/kg and 500 mg/kg. At the end of the experimental period, diabetic rats treated with aqueous extract at both dose levels showed a significant increase in the levels of enzymatic antioxidants such as glutathione peroxidase, glutathione synthetase, peroxidase, superoxide dismutase and catalase as compared to the untreated control. Similarly, a significant increase was also observed in the levels of the non enzymatic antioxidants ceruloplasmin, ascorbic acid and tocopherol. The results suggest that the aqueous stem extract of C. fenestratum prevents type 2 diabetes mellitus induced oxidative stress.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.7
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• pp.919-925
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• 2006

The study was carried out to prepare oyster hydrolysates by using Alcalase, Flavourzyme, Neutrase, Protamex, pepsin and trypsin, and to investigate its functional properties. The ACE inhibitory activity and antioxidant activity of enzymatic oyster hydrolysates did not increase with hydrolysis time. Among enzymatic oyster hydrolysates, oyster hydrolysates incubated with Protamex for 1 hr (OHP) showed the most excellent ACE inhibitory activity and antioxidant activity, and their $IC_{50}$ values were 1.16 mg/mL and 1.49 mg/mL, respectively. However, all enzymatic oyster hydrolysates were not detected in antimicrobial activity.

• Fisheries and Aquatic Sciences
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• v.5 no.4
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• pp.263-270
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• 2002

The Pacific oysters, Crassostrea gigas, were stressed with different concentrations of benzo(a) pyrene and depurated to determine the hemocyte lysosomal membrane stability and hydrolytic enzymatic activity as a biomarker candidate to the chemical, using NRR (neutral red retention) and API ZYM System, respectively. The membrane damage measured as NRR decrease was significant with the increase of chemical concentration and exposure time (P<0.05), providing a possible tool for biomarker. Interestingly, the control showed intrinsic stress probably due to captive life in the laboratory, and a recovering trend was also found during the depuration. The benzo(a)pyrene-exposed oysters showed increased enzyme activities in alkaline phosphatase, esterase (C4), acid phosphatase, naphthol-AS-BI-phospho­hydrolase, $\beta$-galactosidase, $\beta$-glucuronidase, and N-acetyl- $\beta$-glucosaminidase. Of them, only two enzymes, acid phosphatase and alkaline phosphatase, showed some potential available for the generation of enzymatic biomarker in the oyster. The results are suggestive of the potential availability of the cellular and enzymatic properties as a biomarker. However, considering that a robust biomarker should be insensitive to natural stress coming from normal physiological variation, but sensitive to pollutants, a concept of intrinsic stress the animal possesses should be taken into consideration. This reflects the necessity of further research on the intrinsic stress affecting the cellular and enzymatic properties of the chemical­stressed oysters prior to using the data as a biomarker.

• Archives of Plastic Surgery
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• v.34 no.1
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• pp.13-17
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• 2007

Purpose: To understand the pathogenesis of the disease that presents abnormally proliferated vascular endothelial cells, a model of DMH(1,2-dimethylhydrazine)-induced abnormal proliferation of HUVECs(Human Umbilical Vein Endothelial Cells) was made. We indirectly determined that Protein Kinase C(PKC) restricts the cellular proliferation and inhibits the manifestation of growth factor by using several inhibiting substances of the transmitter through our previous studies. Thereupon, we attempted to observe direct enzymatic activities of PKC and its correlation with the abnormal proliferation of vascular endothelial cells. Methods: $10^5$ HUVECs cells were applied to 6 individual well plates in three different groups; A control group cultured without treatment, a group concentrated with $0.75{\times}10^{-8}M$ DMH only, and a group treated with DMH & $5{\times}10^{-9}M$ Calphostin C, inhibitor of PKC. In analyzing the formation of intracellular PKC enzyme, protein separation was performed, and separated protein was quantitatively measured. PKC enzyme reaction was analyzed through Protein Kinase C Assay System (Promega, USA), and the results were analyzed according to Beer's law. Results: Enzymatic activity of PKC presented the highest in all reaction time of a group concentrated only with DMH, and the lowest in the control group. The group treated with DMH and the inhibitor revealed statistically lower enzymatic activity than group only with DMH in all reaction time, although higher than the control group. Conclusion: From the enzymatic aspect, most active and immediate reaction of the PKC was observed in the group concentrated with DMH only. The group treated with DMH & PKC inhibitor showed meaningful decrease. Accordingly, PKC holds a significant role in DMH-induced abnormal proliferation of vascular endothelial cells.

• Journal of Applied Biological Chemistry
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• v.64 no.1
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• pp.97-102
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• 2021

In this study, enzymes were screened for hydrolysis of defatted perilla seed residue (DPSR) and optimal conditions for enzymatic treatment were determined to produce the hydrolysate of DPSR. Also its antioxidant activity and utilization as a culture medium were examined. The combined treatment of Alcalase and Ceremix is most effective for solubilization of protein and carbohydrate in DPSR. The optimal dosage, pH, and reaction time for enzymatic treatment were found to be 2.0% (w/w), 7.0, and 2 h, respectively. Treatment with optimal conditions of enzymes dramatically increased reducing sugar, soluble protein, and total phenolic content. The hydrolysate of DPSR possessed better scavenging activity against cation and free radicals than enzyme-untreated extract. When Leuconostoc mesenteroides 310-12 was cultured in the hydrolysate of DPSR, cell population rapidly increased compared to enzyme-untreated extract, and titratable acidity increased in proportion to the bacterial growth. In conclusion, these results imply that the hydrolysate of DPSR could be utilized as a bacteria culture medium as well as a physiologically active material with antioxidant activity.