• International Journal of Industrial Entomology and Biomaterials
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• v.2 no.1
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• pp.7-13
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• 2001

Enzymatic hydrolysis of different forms of silk fibroin (soluble, gel and insoluble forms) by industrial and commercial enzyme preparations to obtain aqueous and powdered silk fibroin in relatively mild conditions was investigated. A mono-enzymatic hydrolysate systems were tested for hydrolysis of water-soluble form of fibroin as most productive form of protein substrate. Insoluble forms of substrate usually were hydrolyzed less effective. In some cases from soluble fibroin substrate gel was formed during hydrolysis process. This hindered intermixing and decreased rates of hydrolysis. Insoluble sediments were formed in enzymatic hydrolysates in other cases. These sediments and also sediment after chemical hydrolysis were purified and tested on amino acids content for comparison. Sediments formation in these conditions are considered as pure tyrosine isolation method. Obtained hydrolysates were characterized by gel-chromatography analysis and other standard biochemical methods. Possibility of application of enzymatic hydrolysis for preparation of silk fibroin hydrolysates is discussed.

• The Korean Journal of Food & Health Convergence
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• v.10 no.2
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• pp.7-11
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• 2024

Glutathione (GSH) is a vital compound composed of glutamic acid, cysteine, and glycine, crucial for cellular functions including oxidative stress defense and detoxification. It has widespread applications in pharmaceuticals, cosmetics, and food industries due to its antioxidant properties and immune system support. Two primary methods for GSH synthesis are enzymatic and microbial fermentation. Enzymatic synthesis is efficient but costly, while microbial fermentation, particularly using yeast strains like Candida albicans, offers a cost-effective alternative. This study focuses on genetically modifying C. albicans mutants, specifically targeting glutathione reductase (GLR1) and gamma-glutamylcysteine synthetase (GCS1) genes, integral to GSH synthesis. By optimizing these mutants, the research aims to develop a model for efficient GSH production, potentially expanding its applications in the food industry.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.41 no.5
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• pp.15-19
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• 2009

Ammonia soaking treatment was introduced for hemp woody core pretreatment to increase enzymatic saccharification of polysaccharides. Portions of the xylan, cellulose, and lignin were removed by aqueous ammonia soaking, which improved the enzymatic saccharification of cellulose and xylan. Following ammonia soaking, 37% ($50^{\circ}C$-6 day treatment) to 61% ($90^{\circ}C$-16 h treatment) of the cellulose was converted to glucose and 33% ($50^{\circ}C$-6 day treatment) to 48% ($90^{\circ}C$-16 h treatment) of the xylan to xylose. Cellulose responded better to enzymatic saccharification than did xylan after the ammonia soaking treatment. Aqueous ammonia soaking pretreatment was more effective than electron beam irradiation for increasing enzymatic saccharification of xylan and cellulose in hemp woody core.

• Proceedings of the Ginseng society Conference
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• 1993.09a
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• pp.171-178
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• 1993

The effects of Korean Red Ginseng (KRG) in rats submitted to exhaustion exercise have been studied, by measuring different enzymatic and hematological parameters in plasma and muscle. KRG powder was daily administered to 15 male Wistar rats for a period of two weeks. Another group of 15 rats with the same characteristics were administered physiological saline. Both groups were divided as follows: 5 control. 5 exercised till exhaustion and 5 recovered for 48 h after exhaustion. The following results were obtained for the groups treated with KRG in rapport to those treated with saline: - Higher endurance to running, - Increase of the osmotic resistence of red blood cells and higher presence of reticulocytes. - Lower triglyceride levels in plasma. - Increase non statistically significant of urea levels in plasma, - Lower non statistically significant hypoglycemia after exhaustion exercise. - Decrease of liver glycogen after exercise and faster recovery of the resting - level. - Protective effect on tissular damage produced by exhaustion exercise - Lower LDH activity in all studied muscles. only statistically significant in the WG.

• The Korean Journal of Physiology and Pharmacology
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• v.9 no.3
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• pp.137-141
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• 2005

This study was undertaken to investigate the effects of [$D-Ala^2$, D-Leu^5$]-enkephalin (DADLE) on the spontaneous activity of medial vestibular nuclear neurons of the rat. Sprague-Dawley rats, aged 14 to 16 days, were anesthetized with ether and decapitated. After enzymatic digestion, the brain stem portion of medial vestibular nuclear neuron was obtained by micropunching. The dissociated neurons were transferred to a recording chamber mounted on an inverted microscope, and spontaneous action potentials were recorded by standard patch-clamp techniques. The spontaneous action potentials were increased by DADLE in 12 cells and decreased in 3 cells. The spike frequency and resting membrane potential of these cells were increased by DADLE. The depth of afterhyperpolarization was not affected by DADLE. The potassium currents were decreased in 20 cells and increased in 5 cells. These results suggest that DADLE increases the neuronal activity of the medial vestibular nuclear neurons by altering resting membrane potential.

• Food Science and Biotechnology
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• v.17 no.2
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• pp.279-286
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• 2008

The antioxidative activity of various enzymatic extracts from leaves of Perilla frutescens var. japonica was evaluated by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl, and alkyl radical scavenging activity using an electron spin resonance (ESR) spectrometer. For this study, the leaves were enzymatically hydrolyzed by 8 carbohydrases (Dextrozyme, AMG, Promozyme, Maltogenase, Termamyl, Viscozyme, Celluclast, and BAN) and 9 proteases [Flavourzyme, Neutrase, Protamex, Alcalase, PP-trypsin (trypsin from porcine pancreas), papain, pepsin, $\alpha$-chymotrypsin, and BP-trypsin (trypsin from bovine pancreas)]. The DPPH radical scavenging activities of Promozyme and Alcalase extracts were the highest, and the $IC_{50}$ values were 77.25 and $109.66\;{\mu}g/mL$, respectively. All enzymatic extracts of the leaves scavenged hydroxyl radical, and the $IC_{50}$ values of Celluclast and pepsin extracts which were the highest activity were 243.34 and $241.86\;{\mu}g/mL$, respectively. The BAN and $\alpha$-chymotrypsin extracts showed the highest scavenging activities, and the $IC_{50}$ values were 21.13 and $33.23\;{\mu}g/mL$, respectively. The pepsin extracts from the leaves showed protective effect on $H_2O_2$-induced DNA damage. In addition, the pepsin extracts decreased cell death in PC-12 cells against $H_2O_2$-induced oxidative damage. The findings of the present study suggest that enzymatic extracts of the leaves possess antioxidative activity.

• The Korean Journal of Physiology and Pharmacology
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• v.10 no.3
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• pp.131-135
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• 2006

Coeruleo-vestibular pathway which connects locus coeruleus and vestibular nuclei is noradrenergic. This study was designed to elucidate the effects of phenylephrine on the spontaneous activity of acutely isolated medial vestibular nuclear neurons of rat by whole-cell patch-clamp technique. Sprague-Dawley rats, aged 14 to 16 days, were used. After enzymatic digestion, dissociated medial vestibular neurons were transferred to a recording chamber mounted on an inverted microscope, and spontaneous action potentials were recorded by standard patch-clamp techniques. In current-clamp mode, the frequency of spontaneous action potential of medial vestibular nuclear neurons was decreased by phenylephrine (n=15). Phenylephrine increased the amplitude of afterhyperpolarization without changes in the resting membrane potential and spike width. In voltage-clamp mode, the whole potassium currents of the medial vestibular nuclear neurons were increased by phenylephrine (n=12). These experimental results suggest that ${\alpha}-receptor$ mediates the inhibitory effects on the neuronal activity of the medial vestibular nuclear neuron.

• Journal of Mushroom
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• v.5 no.3_4
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• pp.91-97
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• 2007

Shiitake mushroom (Lentinula edodes) is usually cultivated on the oak log. Log cultivation of this mushroom is getting difficult to get oak logs and has a weak point of its long cultivation period. Recently sawdust cultivation is getting increase. It is important to make mycelia browning on the substrate surface. This browned surface in sawdust cultivation plays an important role like as artificial bark of the oak log, which protects the other pests and suppresses water evaporation in the substrate. The period for mycelia browning is so long that the sawdust cultivation of Shiitake mushroom can not spread well into the mushroom farms. The development of methods for the rapid mycelia browning is quite required. In this article we would like to discuss about the enzymatic activities related mycelia browning and search the methods of cultivation period reduction.

• The Korean Journal of Physiology and Pharmacology
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• v.25 no.2
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• pp.159-166
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• 2021

Nicotinamide adenine dinucleotide phosphate oxidases (NOXs) are the major enzymatic source of reactive oxygen species (ROS). NOX2 and NOX4 are expressed in the heart but its role in hypoxia-induced atrial natriuretic peptide (ANP) secretion is unclear. This study investigated the effect of NOX on ANP secretion induced by hypoxia in isolated beating rat atria. The results showed that hypoxia significantly upregulated NOX4 but not NOX2 expression, which was completely abolished by endothelin-1 (ET-1) type A and B receptor antagonists BQ123 (0.3 μM) and BQ788 (0.3 μM). ET-1-upregulated NOX4 expression was also blocked by antagonists of secreted phospholipase A2 (sPLA2; varespladib, 5.0 μM) and cytosolic PLA2 (cPLA2; CAY10650, 120.0 nM), and ET-1-induced cPLA2 expression was inhibited by varespladib under normoxia. Moreover, hypoxia-increased ANP secretion was evidently attenuated by the NOX4 antagonist GLX351322 (35.0 μM) and inhibitor of ROS N-Acetyl-D-cysteine (NAC, 15.0 mM), and hypoxia-increased production of ROS was blocked by GLX351322. In addition, hypoxia markedly upregulated Src expression, which was blocked by ET receptors, NOX4, and ROS antagonists. ET-1-increased Src expression was also inhibited by NAC under normoxia. Furthermore, hypoxia-activated extracellular signal-regulated kinase 1/2 (ERK1/2) and protein kinase B (Akt) were completely abolished by Src inhibitor 1 (1.0 μM), and hypoxia-increased GATA4 was inhibited by the ERK1/2 and Akt antagonists PD98059 (10.0 μM) and LY294002 (10.0 μM), respectively. However, hypoxia-induced ANP secretion was substantially inhibited by Src inhibitor. These results indicate that NOX4/Src modulated by ET-1 regulates ANP secretion by activating ERK1/2 and Akt/GATA4 signaling in isolated beating rat hypoxic atria.

• The Korean Journal of Pain
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• v.35 no.3
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• pp.271-279
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• 2022

Background: Inflammation is known to underlie the pathogenesis in neuropathic pain. This study investigated the anti-inflammatory and neuroprotective mechanisms involved in antinociceptive effects of co-administration of acetaminophen and L-carnosine in chronic constriction injury (CCI)-induced peripheral neuropathy in male Wistar rats. Methods: Fifty-six male Wistar rats were randomly divided into seven experimental groups (n = 8) treated with normal saline/acetaminophen/acetaminophen + L-carnosine. CCI was used to induce neuropathic pain in rats. Hyperalgesia and allodynia were assessed using hotplate and von Frey tests, respectively. Investigation of spinal proinflammatory cytokines and antioxidant system were carried out after twenty-one days of treatment. Results: The results showed that the co-administration of acetaminophen and L-carnosine significantly (P < 0.001) increased the paw withdrawal threshold to thermal and mechanical stimuli in ligated rats compared to the ligated naïve group. There was a significant (P < 0.001) decrease in the levels of nuclear factor kappa light chain enhancer B cell inhibitor, calcium ion, interleukin-1-beta, and tumour necrotic factor-alpha in the spinal cord of the group coadministered with acetaminophen and L-carnosine compared to the ligated control group. Co-administration with acetaminophen and L-carnosine increased the antioxidant enzymatic activities and reduced the lipid peroxidation in the spinal cord. Conclusions: Co-administration of acetaminophen and L-carnosine has anti-inflammatory effects as a mechanism that mediate its antinociceptive effects in CCI-induced peripheral neuropathy in Wistar rat.