• Bulletin of the Korean Chemical Society
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• v.12 no.5
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• pp.504-509
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• 1991

S. fradiae showed very high activity of isocitrate dehydrogenase compared to other microorganisms. The activity of this enzyme was increased with the growth of the organism. But the increase might not imply its involvement in the growth. Rather its increased activity seemed to have a connection with the biosynthesis of neomycin. The enzyme showed high specificity toward $NADP^+$ and D-isocitrate with Km values of 5.75 and 6.74 uM, respectively, It was activated by $Mn^{2+}$. Its molecular weight was estimated from its gel retardation coefficient to be in the range of 61,000-63,000 daltons and its optimum pH was 8.0. The enzyme was thermally unstable.

• Mycobiology
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• v.46 no.4
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• pp.396-406
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• 2018

A newly isolated white rot fungal strain KU-RNW027 was identified as Trametes polyzona, based on an analysis of its morphological characteristics and phylogenetic data. Aeration and fungal morphology were important factors which drove strain KU-RNW027 to secrete two different ligninolytic enzymes as manganese peroxidase (MnP) and laccase. Highest activities of MnP and laccase were obtained in a continuous shaking culture at 8 and 47 times higher, respectively, than under static conditions. Strain KU-RNW027 existed as pellets and free form mycelial clumps in submerged cultivation with the pellet form producing more enzymes. Fungal biomass increased with increasing amounts of pellet inoculum while pellet diameter decreased. Strain KU-RNW027 formed terminal chlamydospore-like structures in cultures inoculated with 0.05 g/L as optimal pellet inoculum which resulted in highest enzyme production. Enzyme production efficiency of T. polyzona KU-RNW027 depended on fungal pellet morphology as size, porosity, and formation of chlamydospore-like structures.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2005.10a
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• pp.46-46
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• 2005

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2005.10a
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• pp.46-46
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• 2005

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.05a
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• pp.24-42
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• 2002

Antioxidant responsive element (ARE) mediates the transcriptional activation of the genes encoding phase II drug metabolizing enzymes and antioxidative stress genes. The ARE consensus sequence shows high similarity to NF-E2 binding sequence, a cisacting erythroid gene regulatory element.(omitted)

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2004.05a
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• pp.99-99
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• 2004

• BMB Reports
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• v.31 no.3
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• pp.249-253
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• 1998

The developmental regulation of Caenorhabditis elegans DNA topoisomerase I expression was examined using synchronized Caenorhabditis elegans cultures. Variations of the relative mRNA and protein levels of the enzyme during their development were measured by Northern and Western analyses, respectively. The mRNA level was the highest at the embryonic stage, decreasing rapidly to the one tenth level at the L1 stage, and then increasing by a few fold at the L4 and young adult stages. The protein level was the highest at the L1 stage, with gradual decreasing at the following stages until it showed a slight increase at the young adult stage. Based on our results of the expressional regulation, the possible roles of DNA topoisomerase I in the development of C. elegans are discussed.

• Archives of Pharmacal Research
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• v.21 no.1
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• pp.35-40
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• 1998

Human cytochrome P450 4F2 shows high regioselectivity in hydroxylation of stearic acid and leukotriene $ B_4.$ As a first step of its regulation study, human cytochrome P450 4F2 genomic DNA was isolated from liver of a person who was administered clofibrate for 10 years. From Southern hybridization, restriction enzyme digestion and sequencing experiments, isolated genomic DNA fragment was found to contain around 32 Kb DNA and more than 20 Kb of $5^I$ end regulatory region. Sequences of the structural gene region revealed exon 1 and exon 2. Further regulation studies would elucidate the feedback mechanisms of the oxidative degradation of fatty acids, inflammatory response and the clearance of leukotriene B4 in the liver. Furthermore, regulation study of this gene could explain the species difference in responses to peroxisome proliferator and help in the safety evaluation of peroxisome proliferating chemicals to human being.

• The Korean Journal of Zoology
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• v.34 no.1
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• pp.123-130
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• 1991

Several parameters of u -glycerol-3-pholphate dehydrogenase (GPDH) such as activity, content and translatable mRNA levels were measured to elucidate mechanism underlving developmental and tissue specific regulation of 6PDH activity in Drosophila melonogastrr. In adult segments, most of total GPDH activity (62%1 Iwas detected in thorax where GPDH-1 resided, while 32% of total GPDH aUiviD was only detected in abdomen where GPDH-3 resided. The relative synthesis of GPDH was, however, similar in both tissues, although 58% of total GPDH was synthesized in abdomen. These results strongly suggest that the turnover rate of the abdominal enzyme (GPDH-3) was much more rapid than that of thoracic enzymes (GPDH-1). In nitro translation and immunoblotting experiments also indicate that GPDH-3 was arised by posttranslational modification from a single polypeptide (GPDH-1).

• Toxicological Research
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• v.31 no.4
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• pp.339-345
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• 2015

CYP1A1 is a phase I xenobiotic-metabolizing enzyme whose expression is mainly driven by AhR. Endosulfan is an organochlorine pesticide used agriculturally for a wide range of crops. In this study, we investigated the effect of endosulfan on CYP1A1 expression and regulation. Endosulfan significantly increased CYP1A1 enzyme activity as well as mRNA and protein levels. In addition, endosulfan markedly induced XRE transcriptional activity. CH-223191, an AhR antagonist, blocked the endosulfan-induced increase in CYP1A1 mRNA and protein expression. Moreover, endosulfan did not induce CYP1A1 gene expression in AhR-deficient mutant cells. Furthermore, endosulfan enhanced the phosphorylation of calcium calmodulin (CaM)-dependent protein kinase (CaMK) and protein kinase C (PKC). In conclusion, endosulfan-induced up-regulation of CYP1A1 is associated with AhR activation, which may be mediated by PKC-dependent pathways.