• The Korean Journal of Food And Nutrition
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• v.9 no.2
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• pp.143-150
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• 1996

The studies was carried out to investigate ripening degree and functional properties of EMC produced with pancreatic protease and palatase ML. During production of EMC, the amounts of free amino acid and free fatty acid were increased with increasing the reaction time. The amount of total nitrogen(T-N) and water soluble nitrogen(WSN) were increased with increasing time. EMC had contents of 1.79eA T-N and 0.52o WSN at 60 min of hydrolysis time. SRI and FRI value had also a similar correlationship. On the gel filtration, 2 kinds of soluble proteining capacity was also shown in alkali solution. Furthermore the foaming stability had the same result as that of the solubility. The water absorption of EMC showed the highest level at pH 4.0 and 5.0.

• Microbiology and Biotechnology Letters
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• v.24 no.4
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• pp.452-458
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• 1996

A yeast strain TH65 producing a high level of proteinase under alkaline condition was isolated, and identified as Yarrowia lipolytica by morphological, physiological, and biochemical characteristics. In proteinase productivity, glycerol and glucose among tested carbon sources were very effective, and optimum concentration of glucose was 0.5%. Skim milk was found to be most effective nitrogen source in productivity, and its optimum concentration was 0.6%. But, cysteine, cystine and tryptophane decreased the proteinase productivity. Yeast extract was relatively effective at the range of 0.1-0.5%. The yeast showed maximum production of proteinase at 18$\circ$C, pH 9-11, and cultivation time of 36 hours.

• Food Science of Animal Resources
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• v.41 no.1
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• pp.164-171
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• 2021

Listeria monocytogenes is a representative foodborne pathogen and causes listeriosis. Enterococcus faecium CJNU 2524 was confirmed to produce a bacteriocin with anti-listerial activity. To establish optimal culture conditions for the production of the bacteriocin from E. faecium CJNU 2524, different media (MRS and BHI broth) and temperatures (25℃, 30℃, and 37℃) were investigated. The results showed that the optimal culture conditions were MRS broth and 25℃ or 30℃ temperatures. The crude bacteriocin was stable in a broad range of pH conditions (2.0-10.0), temperatures (60℃-100℃), and organic solvents (methanol, ethanol, acetone, acetonitrile, and chloroform). The bacteriocin activity was abolished when treated with protease but not α-amylase or lipase, indicating the proteinaceous nature of the bacteriocin. Finally, the bacteriocin showed a bactericidal mode of action against L. monocytogenes. Therefore, it can be a biopreservative candidate for controlling L. monocytogenes in dairy and meat products.

• International Journal of Industrial Entomology and Biomaterials
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• v.45 no.2
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• pp.43-48
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• 2022

Bombyx mori is a representative industrial insect and is used in silk production. Additionally, it serves as an insect model in molecular studies. To date, various molecular studies on its physiological characteristics, including the innate immune response and cuticular melanization, have been conducted. The melanization, including cuticular melanization, in insects is controlled by the prophenoloxidase-activating system, which is also involved in their innate immune response. In this review, to better understand the molecular mechanisms underlying the prophenoloxidase-activating system in the silkworm, the roles of five biomolecules, namely tyrosine hydroxylase, prophenoloxidase-activating enzyme, phenoloxidase, serine protease homolog, and immulectin, are discussed.

• Journal of the Korean Magnetic Resonance Society
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• v.27 no.2
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• pp.5-9
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• 2023

t ENOD40B, a plant peptide hormone, was doubly labeled with C-13 and N-15 by recombinant production in Escherichia coli. The peptide was prepared by affinity chromatography followed by protease cleavage and reverse-phase chromatography. To elucidate the mode of action against its receptor, sucrose synthase, we proceeded to assign the backbone and side-chain resonances using a set of double and triple resonance experiments. This result will be used to determine the three-dimensional structure of the peptide at its bound state as well as to observe the chemical shift changes upon binding.

• Applied Biological Chemistry
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• v.22 no.3
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• pp.135-141
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• 1979

These experiments were conducted to investigate the conditions of the acid protease production by Rhizopus oryzae and the characteristics of crude enzyme. The results obtained were as follows: 1. The optimum culture time and the optimum amount of added water to the wheat bran medium were about 48 hrs and $80{\sim}120%$, respectively. 2. The addition of $(NH_4)_6Mo_7O_{24},\;(NH_4)_2SO_4,\;NH_4NO_3$, casein, and albumin, respectively, as nitrogen sources to the wheat bran medium was effective. Of these, the optimum concentrations of addition of $(NH_4)_6Mo_7O_{24}$ and casein which were the most effective were 0.1% and 1.0%, respectively. 3. The addition of glucose, galactose, maltose, lactose, and soluble starch, respectively, as carbon sources to the wheat bran medium was effective. Of these, the optimum concentration of addition of glucose which was the most effective was 3.0%. 4. The addition of $KH_2PO_4$ as a phosphate salt to the wheat bran medium was effective. The optimum concentration of addition of $KH_2PO_4$ was 0.3%. 5. The optimum pH for the enzyme action was 2.4, the optimum temperature about $40^{\circ}C$, and the stable pH range $2.0{\sim}5.0$. The enzyme was stab1e below $40^{\circ}C$. 6. The enzyme activity increased rapidly for 10 minutes after addition, thereafter it increased slowly. 7. The enzyme activity increased rapidly to 2 ml of addition, but nearly did not increase at the amounts greater than 2ml.

• Journal of Plant Biotechnology
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• v.32 no.4
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• pp.313-319
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• 2005

The effects of various carbon sources on the secretion of hGM-CSF, total protein and protease into the medium were investigated in transgenic tobacco cells. The dry cell weight (11.2 g/L) and wet cell weight (310.8 g/L) were highest at 30 g/L glucose after 5-day culture but, the dry cell weight (13.4 g/L) and wet cell weight (480 g/L) were highest at 30 g/L sucrose after 10-day culture. The total protein (110.3 mg/L), protease activity (3950 U/L) and total secreted hGM-CSF (56 mg/L) were highest at 30 g/L sucrose after 10-day culture. Stabilization of the total secreted protein and hGM-CSF in various carbon source concentrations was determined. Total secreted protein was most stabilized in the medium containing sucrose. However, the loss of the total protein was increased with the concentrations of high level in medium containing sorbitol, mannitol, fructose, and glucose. hGM-CSF was more stabilized in the medium containing sucrose than in the medium containing sorbitol, mannitol, fructose, glucose.

• Microbiology and Biotechnology Letters
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• v.39 no.4
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• pp.357-363
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• 2011

This study focus was primarily the development of liquid starters for Aspergillus oryzae and Aspergillus niger prepared with wheat bran as a low cost culture medium. For the preparation of the liquid media wheat bran was added at rates of 0, 5, 10, 15 and 20% and the Aspergillus sp. strains were then inoculated to these prepared broths. The results indicated that the more that wheat bran was contained in the medium, the more mycelia was produced for A. oryzae and A. niger. The highest enzyme activities were obtained with a 10~15% adding rate of wheat bran for both strains. Changes in the enzyme activities of the liquid starters during various incubation times (0, 24, 48, 72 and 96 hrs), indicated that the highest enzyme activities were seen between 48 and 72 hrs of culture. In addition, a comparative study was carried out on the production of enzymes using wheat as a substrate in nuruk, with liquid starter made from fermented agents according to the same concentrations used with the wheat bran. The pH, acidity, amino acidity, reducing sugar content and enzyme activity (${\alpha}$-amylase, glucoamylase, acidic protease) of wheat nuruk made with liquid starter were compared with those of wheat nuruk made with solid starter. The results suggest that the liquid starter is superior in both cases.

• Journal of Environmental Science International
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• v.22 no.6
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• pp.723-732
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• 2013

This study was carried out to investigate changes of protease and amylase activities and nitrogen content in Chungkookjang prepared by Bacillus subtilis S8 and different soybean. Amino-type nitrogen and ammonia-type nitrogen contents increased with an increase in fermentation time and was the highest in black soybean Chungkookjang. The number of viable cells increased up to 24 h of fermentation at all temperatures tested; especially, their levels were the highest at $40^{\circ}C$. Protease activity was the highest in black soybean Chungkookjang. ${\alpha}$-amylase activity increased significantly up to 6 h of fermentation at $30^{\circ}C$ and $40^{\circ}C$ and then maintained constantly. It also increased up to 30-36 h of fermentation at $45^{\circ}C$ and then decreased. ${\beta}$-amylase activity was the highest in black soybean Chungkookjang at $35^{\circ}C$ and $40^{\circ}C$ and in yellow soybean Chungkookjang at $45^{\circ}C$. Production pattern of reducing sugar was similar to that of ${\beta}$-amylase. Amino-type nitrogen, viable cell number and reducing sugar content and ${\beta}$-amylase activity was the highest in Chungkookjang fermented at $40^{\circ}C$. Considering amino-type and ammonia-type nitrogen contents, Chungkookjang fermentation using yellow soybean was favorable. However, the fermentation using black soybean was favorable, considering protease and amylase activities and reducing sugar content.

• Journal of Life Science
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• v.16 no.5
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• pp.716-722
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• 2006

Superoxide dismutase (SOD) is physiologically important in regulating cellular homeostasis and apoptotic cell death, and its mutations are the cause of familial amyotrophic lateral sclerosis (FALS). Mitochondrial serine protease HtrA2 has a pro-apoptotic function and has known to be associated with neurodegenerative disorders. To investigate the relationship between genes associated with apoptotic cell death, such as HtrA2 and SOD1, we utilized the pGEX expression system to develop a simple and rapid method for purifying wild-type and ALS-associated mutant SOD1 proteins in a suitable form for biochemical studies. We purified SOD1 and SOD1 (G93A) proteins to approximately 90% purity with relatively high yields (3 mg per liter of culture). Consistent with the result in mammalian cells, SOD1 (G93A) was more insoluble than wild-type SOD1 in E. coli, indicating that research on the aggregate formation of SOD1 may be possible using this pGEX expression system in E. coli. We investigated the HtrA2 serine protease activity on SOD1 to assess the relationship between two proteins. Not only wild-type SOD1 but also ALS-associated mutant SOD1 (G93A) were cleaved by HtrA2, resulting in the production of the 19 kDa and 21 kDa fragments that were specific for anti-SOD1 antibody. Using protein gel electrophoresis and immunoblot assay, we compared the relative molecular masses of thrombin-cleaved GST-SOD1 and HtrA2-cleaved SOD1 fragments and can predict that the HtrA2-cleavage sites within SOD1 are the peptide bonds between leucine 9-lysine 10 (L9-K10) and glutamine 23-lysine 24 (Q23-K24). Our study indicates that SOD1 is one of the substrate for HtrA2, suggesting that both HtrA2 and SOD1 may be important for modulating the HtrA2-SOD1-mediated apopotic cell death that is associated with the pathogenesis of neurodegenerative disorder.