• Korean journal of applied entomology
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• v.61 no.1
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• pp.155-163
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• 2022

The application of fungicides is indispensable to global food security, and their use has increased in recent times. Fungicides, directly or indirectly, have impacted insects, leading to genetic and molecular-level changes. Various detoxification mechanisms allow insects to eliminate reactive oxygen species (ROS) toxicity induced by agrochemicals including fungicides. In the present study, we analyzed the mRNA expression levels of detoxifying enzymes in Tenebrio molitor larvae following exposure to non-lethal doses (0.2, 2, and 20 ㎍/µL) of a fungicide captan. Transcripts of peroxidases (POXs), catalases (CATs), superoxide dismutases (SODs), and glutathione-s-transferases (GSTs) were screened from the T. molitor transcriptome database. RT-qPCR analysis showed that TmPOX5 mRNA increased significantly 24 h post-captan exposure. A similar increase was noticed for TmSOD4 mRNA 3 h post-captan exposure. Moreover, the expression of TmCAT2 mRNA increased significantly 24 h post-treatment with 2 ㎍/µL captan. TmGST1 and TmGST3 mRNA expression also increased noticeably after captan exposure. Taken together, these results suggest that TmPOX5 and TmSOD4 mRNA can be used as biomarkers or xenobiotics sensors for captan exposure in T. molitor, while other detoxifying enzymes showed differential expression.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.1
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• pp.81-87
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• 2013

Quercetin-3-O-${\beta}$-D-glucuronopyranoside (QGC) is a flavonoid glucoside extracted from Rumex Aquaticus Herba. In the present study, anti-oxidative and anti-inflammatory effects of QGC were tested in vitro. Epithelial cells obtained from cat esophagus were cultured. When the cells were exposed to acid for 2 h, cell viability was decreased to 36%. Pretreatment with 50 ${\mu}M$ QGC for 2 h prevented the reduction in cell viability. QGC also inhibited the productions of intracellular ROS by inflammatory inducers such as acid, lipopolysaccharide, indomethacin and ethanol. QGC significantly increased the activities of superoxide dismutase (SOD) and catalase, and also induced the expression of SOD2, while it restored the decrease of catalase expression in cells exposed to acid. QGC inhibited NF-${\kappa}B$ translocation, cyclooxygenase-2 expression and $PGE_2$ secretion in cells exposed to acid, which plays an important role in the pathogenesis of esophagitis. The data suggest that QGC may well be one of the promising substances to attenuate oxidative epithelial cell injury and inflammatory signaling in esophagus inflammation.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.6
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• pp.742-749
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• 2010

We investigated the antioxidant efficacy of quercetin (0% Diet 1, 0.25% Diet 2, and 0.5% Diet 3) pretreatment for 30 and 60 days in response to cadmium (Cd) toxicity in the olive flounder, and measured the plasma lysozyme activity to understand the immune effects of quercetin. The lysozyme activity with Diets 2 and 3 was higher than with Diet 1. Based on this result, to examine the immune ability and antioxidant role of quercetin, we exposed olive flounder fed quercetin to Cd and then measured the expression and activity of antioxidant enzymes (superoxide dismutase (SOD) and catalase (CAT)) and lipid peroxidation (LPO). With Diets 2 and 3, the expression and activity of antioxidant enzymes and the $H_2O_2$ concentration were lower than with Diet 1. In addition, the LPO levels were lower than with Diet 1, which protected the cell membrane. Therefore, quercetin removed the reactive oxygen species (ROS) produced by Cd, indicating that quercetin has antioxidant ability. In addition to its antioxidant ability, quercetin has immune effects.

• Applied Biological Chemistry
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• v.38 no.2
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• pp.118-122
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• 1995

Escherichia Coli ornithine transcarbamylase is the enzyme which catalyzes the L-citrulline biosynthesis from L-ornithine and carbamyl phosphate. To facilitate the purification of enzyme which will be used for many biochemical studies such as structure and function relationships and catalytic mechanisms, the cloning and expression of E. coli argI gene for ornithine transcarbamylase was conducted. argI was amplified from genomic DNA of E. coli strain of $DH5{\alpha}$, by polymerization chain reaction (PCR) method. The amplified argI gene was ligated to the prokaryotic expression vector pKK223-3 and used for transformation of E. coli TB2 which was deficient of ornithine transcarbamylase. The over-produced enzyme by the tnansformant was purified by ammonium sulfate fractionation, heat denaturation and affinity chromatography. The result of SDS denaturation gel electrophoresis for the purified enzyme showed a single band of about 38 kDa of ornithine transcarbamylase. Kinetic data for the expressed enzyme gave almost the s?????? values as those of the wild type enzyme. The $k_{cat}$, of the enzyme was $1.0{\times}10^5min^{-1}$, and $K_ms$ for ornithine and carbamyl phosphate were 0.35 mM and 0.06 mM, respectively.

• Journal of Aquaculture
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• v.18 no.1
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• pp.7-12
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• 2005

This study was conducted to investigate antioxidant enzyme activity (catalase and superoxide dismutase) and Heat Shock Protein 70 (HSP70) mRNA variation in hepatopancreas of abalone (Haliotis discus hannai) cultured under several acute water temperatures. Abalones were cultured at 10, 15, 20, 25 and $30^{\circ}C$, for 0, 6, 12, 24 and 48 hours, respectively. The HSP70 mRNA expression in hepatopancreas was more increased at $30^{\circ}C$ compared to those at 10. 15, 20 (control) and $25^{\circ}C$. The superoxide dismutase (SOD) activity was increased in hepato-pancreas at all water temperature conditions compared to the control ($20^{\circ}C$). The SOD activity at high water temperature (25 and $30^{\circ}C$) tended to be increased after 12 hours, and was increased immediately after exposure to low water temperature (10 and $15^{\circ}C$). and then was recovered to starting level after the increase. Also, catalase (CAT) activity in hepatopancreas was increased in all the groups except for at $10^{\circ}C$ than the control ($20^{\circ}C$). Survival rate of abalone was $100\%$ at 10, 15, 20 and $25^{\circ}C$, but $92\%$ at $30^{\circ}C$. Thus, according to our study, when abalone is appeared at $20^{\circ}C$, defense mechanism against stress at low water temperature can be accelerated to be stabilized at about $5^{\circ}C$. In the case of exposure of abalone to high water temperature, antioxidant enzyme and HSP70 expression were increased due to elevated physiological stimulation factor, such as temperature.

• Journal of Microbiology and Biotechnology
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• v.22 no.3
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• pp.292-300
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• 2012

We report the expression, purification, and characterization of L-asparaginase (AnsA) from Rhizobium etli. The enzyme was purified to homogeneity in a single-step procedure involving affinity chromatography, and the kinetic parameters $K_m$, $V_{max}$, and $k_{cat}$ for L-asparagine were determined. The enzymatic activity in the presence of a number of substrates and metal ions was investigated. The molecular mass of the enzyme was 47 kDa by SDS-PAGE. The enzyme showed a maximal activity at $50^{\circ}C$, but the optimal temperature of activity was $37^{\circ}C$. It also showed maximal and optimal activities at pH 9.0. The values of $K_m$, $V_{max}$, $k_{cat}$, and $k_{cat}/K_m$ were $8.9{\pm}0.967{\times}10^{-3}$ M, $128{\pm}2.8$ U/mg protein, $106{\pm}2s^{-1}$, and $1.2{\pm}0.105{\times}10^4M^{-1}s^{-1}$, respectively. The L-asparaginase activity was reduced in the presence of $Mn^{2+}$, $Zn^{2+}$, $Ca^{2+}$, and $Mg^{2+}$ metal ions for about 52% to 31%. In addition, we found that $NH_4{^+}$, L-Asp, D-Asn, and ${\beta}$-aspartyl-hydroxamate in the reaction buffer reduced the activity of the enzyme, whereas L-Gln did not modify its enzymatic activity. This is the first report on the expression and characterization of the L-asparaginase (AnsA) from R. etli. Phylogenetic analysis of asparaginases reveals an increasing group of known sequences of the Rhizobial-type asparaginase II family.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.11
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• pp.1286-1292
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• 2017

This study was conducted to investigate the hepatoprotective effects of 3,5-dicaffeoylquinic acid (3,5-DCQA) isolated from Ligularia fischeri against hydrogen peroxide-induced oxidative stress in HepG2 cells. Antioxidative effects of 3,5-DCQA were determined by measuring antioxidant enzyme [superoxide dismutase (SOD), catalase (CAT) glutathione peroxidase (GPx)] expression levels against hydrogen peroxide-induced oxidative stress using real-time PCR analysis. 3,5-DCQA treatment significantly increased gene expression levels of SOD, CAT, and GPx in a dose-dependent manner ($10{\sim}30{\mu}g/mL$) in HepG2 cells. Hepatoprotective effects were analyzed by measuring glutamic oxaloacetic transaminase (GOT), lactate dehydrogenase (LDH), and gamma-glutamyl transferase (GGT) activities using a biochemistry analyzer in hydrogen peroxide-treated HepG2 cells. 3,5-DCQA treatment significantly reduced GOT, LDH, and GGT activities in a dose-dependent manner ($10{\sim}30{\mu}g/mL$) against increased liver function index enzyme activities induced by hydrogen peroxide oxidative stress in HepG2 cells. The results reveal that 3,5-DCQA compound isolated from Ligularia fischeri can be useful for the development of an effective hepatoprotective agent.

• Journal of Life Science
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• v.15 no.4 s.71
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• pp.626-632
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• 2005

The polyamines are essential components of all eukaryotic cells and absolutely necessary for cell growth. In the present study, the cytoprotective role of polyamine was characterized. When $Ac_2F$ rat liver cells were treated with 1M 2,2'-azobis (2-amidinopropane) dehydrochloride (AAPH), a water soluble free radical initiator, viability of the cells was noticeably decreased due to the increase of reactive oxygen species (ROS). The cytotoxic effect of AAPH as well as ROS generation were significantly inhibited by the treatment of polyamines. Among polyamines, especially spermine at $20{\mu}M$ concentration exerted over $45\%$ inhibition of AAPH-induced ROS generation. Western blotting was performed to determine whether superoxide dismutase(SOD) or catalase (CAT) expression was involved in oxidative stress. The AAPH treatment blocked both SOD and CAT protein expressions. Spermine could recover those protein expressions to the untreated control levels. According to the result of cycline E measurement, AAPH might block the entry of the cells into S phase of the cell cycle. The reduced expression of cyclin E protein could be fully recovered by the addition of spermine. The antioxidative effects of spermine was also further proved by the apopotitic morphological analysis using ethidium bromide and acridine orange.

• Journal of Microbiology and Biotechnology
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• v.17 no.8
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• pp.1353-1360
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• 2007

Three csp-like genes were identified in the Corynebacterium glutamicum genome and designated cspA, cspB, and cspA2. The genes cspA and cspA2 encode proteins, comprising of 67 amino acid residues, respectively. They share 83% identity with each other. Identity of those proteins with Escherichia coli Csp proteins was near 50%. The cspB gene encodes a protein composed of 127 amino acids, which has 40% and 35% sequence identity with CspA and CspA2, respectively, especially at its N-terminal region. Analysis of the gene expression profiles was done using transcriptional cat fusion, which identified not only active expression of the three genes at the physiological growth temperature of $30^{\circ}C$ but also growth phase-dependent expression with the highest activity at late log phase. The promoters of cspA and cspA2 were more active than that of cspB. The expression of the two genes increased by 30% after a temperature downshift to $15^{\circ}C$, and such stimulation was more evident in the late growth phase. In addition, the cspA gene appeared to show DNA-binding activity in vivo, and the activity increased at lower temperatures. Interestingly, the presence of cspA in multicopy hindered the growth of the host C. glutamicum cells at $20^{\circ}C$, but not at $30^{\circ}C$. Altogether, these data suggest that cspA, cspB, and cspA2 perform functions related to cold shock as well as normal cellular physiology. Moreover, CspA and its ortholog CspA2 may perform additional functions as a transcriptional regulator.

• The Journal of Korean Society of Virology
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• v.26 no.2
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• pp.151-162
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• 1996

Pseudorabies is caused by Pseudorabies virus (PRV: Aujeszky's disease virus) of Herpesviridae that is characterized by 100 to 150nm in size with a linear double-stranded DNA molecule with of approximately $90{\times}10^6Da$. This disease affects most of domestic animals such as swine, cattle, dog, sheep, cat, chicken, etc. causing high mortality and economic losses. In swine, young piglets show high mortality and pregnant sows, reproductive failures. However the adult swine reveals no clinical signs in general. But they become a carrier state and play an important role for propagation of the disease. In this study, the nucleotide sequence of major casid protein gene of PRV, Yangsan strain isolated from the diseased swine in Korea was analyzed, and the recombinant MCP was produced by expression of the MCP gene in Sf-9 cell using baculovirus transfer vector system. As result, in BamHI digestion, MCP gene locus of PRV YS strain showed different from that of Indiana S strain. The patterns of enzyme mapping were also found to be unidentical each other. The sequence of the MCP gene partially analyzed showed 98.09% identity to Indiana S strain. The expression of MCP in Sf-9 cell cotransfected by pVLMCP-44 baculovirus expression vector was characterized by Southern blot hybridization, immunofluoresent and immunocytochemical tests, SDS-PAGE and Western blotting. The rMCP with M.W. 142kDa was most effectively expressed in Sf-9 cells at the 3-4th days post inoculation of the recombinant baculovirus by 2 moi.