• Journal of Microbiology and Biotechnology
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• 제17권1호
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• pp.67-73
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• 2007

The present study compared the microbial diversity and activity during the application of various bioremediation processes to crude oil-contaminated soil. Five different treatments, including natural attenuation (NA), biostimulation (BS), biosurfactant addition (BE), bioaugmentation (BA), and a combined treatment (CT) of biostimulation, biosurfactant addition, and bioaugmentation, were used to analyze the degradation rate and microbial communities. After 120 days, the level of remaining hydrocarbons after all the treatments was similar, however, the highest rate (k) of total petroleum hydrocarbon (TPH) degradation was observed with the CT treatment (P<0.05). The total bacterial counts increased during the first 2 weeks with all the treatments, and then remained stable. The bacterial communities and alkane monooxygenase gene fragment, alkB, were compared by denaturing gradient gel electrophoresis (DGGE). The DGGE analyses of the BA and CT treatments, which included Nocardia sp. H17-1, revealed a simple dominant population structure, compared with the other treatments. The Shannon-Weaver diversity index (H') and Simpson dominance index (D), calculated from the DGGE profiles using 16S rDNA, showed considerable qualitative differences in the community structure before and after the bioremediation treatment as well as between treatment conditions.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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• pp.54-56
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• 2006

Single-well-gas-sparging tests were developed and evaluated for assessing the feasibility of in-situ aerobic cometabolism of trichloroethylene (TCE), using propane as a growth substrate. To evaluate transport characteristics of dissolved solutes [sulfur hexafluoride (SF6) or bromide (non-reactive tracers), propane (a growth substrate), ethylene, propylene (nontoxic surrogates to probe for CAH transformation activity), and DO], push-pull transport tests were performed. Mass balance showed about 90% of the injected bromide and about 80% of the injected SF6 were recovered, and the recoveries of other solutes were comparable with bromide and slightly higher than SF6. A series of Gas-Sparging Biostimulation tests were performed by sparging propane/oxygen/argon/SF6 gas mixtures, and temporal ground water samples were obtained from the injection well under natural gradient 'drift' conditions. The decreased time for propane depletion and the longer time to deplete SF6 as a conservative tracer indicate the progress of biostimulation. Gas-Sparging Activity tests were performed. .Propane utilization, DO consumption, and ethylene and propylene cometabolism were well demonstrated. The stimulated propane-utilizers cometabolized ethylene and propylene to produce ethylene oxide and propylene oxide, as cometabolic by-products, respectively. Gas-Sparging Acetylene Blocking tests were performed by sparging gas mixtures including acetylene to demonstrate the involvement of monooxygenase enzymes. Gas substrate degradation was essentially completely Inhibited in the presence of acetylene, and no production of the corresponding oxides was also observed. The Gas-Sparging tests supports the evidences that the successive stimulation of propane-oxidizing microorganisms, cometabolic transformation of ethylene and propylene by the enzyme responsible for methane and propane degradation.

• Biomolecules & Therapeutics
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• 제20권6호
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• pp.562-568
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• 2012

Cytochrome P450 BM3 (CYP102A1) from Bacillus megaterium is a self-sufficient monooxygenase that consists of a heme domain and FAD/FMN-containing reductase domain (BMR). In this report, the reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and 5-cyano-2,3-ditolyl tetrazolium chloride (CTC) by BMR was evaluated as a method for monitoring BMR activity. The electron transfer proceeds from NADPH to BMR and then to BMR substrates, MTT and CTC. MTT and CTC are monotetrazolium salts that form formazans upon reduction. The reduction of MTT and CTC followed classical Michaelis-Menten kinetics ($k_{cat}=4120\;min^{-1}$, $K_m=77{\mu}M$ for MTT and $k_{cat}=6580\;min^{-1}$, $K_m=51{\mu}M$ for CTC). Our continuous assay using MTT and CTC allows the simple, rapid measurement of BMR activity. The BMR was able to metabolize mitomycin C and doxorubicin, which are anticancer drug substrates for CPR, producing the same metabolites as those produced by CPR. Moreover, the BMR was able to interact with CYP1A2 and transfer electrons to promote the oxidation reactions of substrates by CYP1A2 and CYP2E1 in humans. The results of this study suggest the possibility of the utilization of BMR as a surrogate for mammalian CPR.

• Applied Biological Chemistry
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• 제40권6호
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• pp.501-507
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• 1997

파라과이 원산의 국화과 식물 Stevia rebaudiana Bertoni는 steviol (ent-13-hydroxy kaur-16-en-19-oic acid)을 기본 골격으로 하는 stevia 감미료를 건물 중량의 5-10%를 생합성하여 축적을 한다. 감미성분은 Gibberellin 생합성의 전구체로 알려진 ent-kaurenoic acid (ent-kaur-16-en-19-oic acid; ent-KA)의 7번과 13번의 어느 탄소에 hydroxylation을 시키느냐에 따라 gibberellin 대사와 steviol 대사로 나뉘어진다. ent-KA 13-hydroxylase를 stevia 엽록체의 stroma에 존재하는 것을 확인했다. Stroma 분획 단백질 $100\;{\mu}g$으로 효소 반응의 cofactor 요구성을 조사해 본 결과, 반응 혼합액에 NADPH를 첨가하지 않았을 때는 85%의 효소활성의 감소를 보였고, NADPH 대신 NADH를 첨가해도 34%의 감소를 보였다. anaerobic 조건에서는 2.1%의 활성을 뛰었다. 이 결과로 ent-KA 13-hydroxylase는 NADPH와 $O_2$ 요구성임을 밝혔다. FAD, FMN, riboflavin을 첨가함으로써 FAD는 1.5배, riboflavin은 1.7배의 효소활성 증가 효과가 나타났다. 효소의 기질 특이성을 조사한 결과, t-cinnamic acid, 4-hydroxyphenyl acetic acid, choline과 resorcinol에는 전혀 활성이 검출되지 않았으며, $[^(14)C]-methyl-KA$를 ent-KA 대신에 기질로 사용했을 때는 16.7% 의 활성이 검출되어 ent-KA 13-hydroxylase는 기질특이성이 높은것으로 확인되었다.

• 한국간담췌외과학회지
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• 제26권1호
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• pp.58-68
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• 2022

Backgrounds/Aims: Mechanisms for the development of hepatocellular carcinoma (HCC) in hepatitis B virus (HBV)-infected patients remain unclear. The aim of the present study was to identify genes and pathways involved in the development of HBV-associated HCC. Methods: The GSE121248 gene dataset, which included 70 HCCs and 37 adjacent liver tissues, was downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) in HCCs and adjacent liver tissues were identified. Gene ontology and Kyoto Encyclopedia of Genes and Genome pathway enrichment analyses were then performed. Results: Of 134 DEGs identified, 34 were up-regulated and 100 were down-regulated in HCCs. The 34 up-regulated DEGs were mainly involved in nuclear division, organelle fission, spindle and midbody formation, histone kinase activity, and p53 signaling pathway, whereas the 100 down-regulated DEGs were involved in steroid and hormone metabolism, collagen-coated extracellular matrix, oxidoreductase activity, and activity on paired donors, including incorporation or reduction of molecular oxygen, monooxygenase activity, and retinol metabolism. Analyses of protein-protein interaction networks with a high degree of connectivity identified significant modules containing 14 hub genes, including ANLN, ASPM, BUB1B, CCNB1, CDK1, CDKN3, ECT2, HMMR, NEK2, PBK, PRC1, RACGAP1, RRM2, and TOP2A, which were mainly associated with nuclear division, organelle fission, spindle formation, protein serine/threonine kinase activity, p53 signaling pathway, and cell cycle. Conclusions: This study identified key genes and carcinogenic pathways that play essential roles in the development of HBV-associated HCC. This may provide important information for the development of diagnostic and therapeutic targets for HCC.

• BMB Reports
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• 제32권3호
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• pp.232-238
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• 1999

Sex differences in the induction of microsomal cytochrome P-450 (CYP) and the activities of several related enzymes of Sprague-Dawley rats treated with 1-bromopropane (1-BrP) were investigated. Male and female rats were exposed to 50, 300, and 1800 ppm of 1-BrP per kg body weight (6 h a day,S days a week, 8 weeks) by inhalation. The mean body weight of 1-BrP treated groups increased according to the day elapsed, but four and five weeks respectively after the start of the exposure, the mean body weight of male and female rats had significantly reduced in the group treated with 1800 ppm 1-BrP compared with the control group (p<0.01). While the relative weights of liver increased in both sexes, statistical significance in both sexes was found only in the group receiving 1800 ppm/kg of 1-BrP (p<0.01). The total contents of CYP, $b_5$, NADPH-P-450 reductase, NADH $b_5$ reductase, ethoxyresorufin-O-deethylase (EROD), pentoxyresorufin-O-dealkylase (PROD), and p-nitrophenol hydroxylase (pNPH) activities were examined for the possible effects of 1-BrP. No significant changes in the CYP and $b_5$ contents, NADPH-P-450 reuctase, NADH $b_5$ reductase, ethoxyresorufin-O-deethylase (EROD), and pentoxyresorufin- O-dealkylase (PROD) were observed between the control and treated groups. The activity of pNPH increased steadily with the increase in the concentration of 1-BrP in both sexes, but was significantly increased only in the 1800 ppm-treated group of male rats (p<0.05). When Western blottings were carried out with three monoclonal antibodies (MAb 1-7-1, MAb 2-66-3, and MAb 1-98-1) which were specific against CYP1A1/2, CYP2B1/2, and CYP2E1, respectively, a strong signal corresponding to CYP2E1 was observed in microsomes obtained from rats treated with 1-BrP. Glutathione S-transferase (GST) activity and the content of lipid peroxide significantly increased in the treated groups compared with the control group (p<0.05). These results suggest that 1-BrP can primarily induce CYP2E1 as the major form and that GST phase II enzymes play important roles in 1-BrP metabolism, showing sex-dependence in the metabolic mechanism of 1-BrP in the rat liver.

• 한국응용곤충학회지
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• 제35권3호
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• pp.254-259
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• 1996

Yumenoshima III 집파리 계통을 ethyl fenitrothion으로 30세대 도태시킨 EF-30 계통에 있어서의 parathion 저항성 메카니즘을 생화학적으로 조사하였다. 아세틸콜린에스테라제 저해활성은 저항성계통과 감수성 SRS 계통간에 커다란 차이를 보여 이 효소의 감수성 저하가 저항성의 주료 메카니즘으로 작용하고 있음을 알 수 있었다. 양 계통에 있어서의 parathion과 paraoxon의 in vitro 분해활성은 미크로좀 및 수용성 분획과 관련이 있으며, 각각 NADPH와 glutathione을 필요로 하였다. 저항성계통은 감수성계통에 비하여 GSH S-transferase 활성이 높아 이 효소가 저항성 메카니즘에 중요한 역할을 하고 있는 것으로 추정되었다. 저항성계통은 parathion에 대하여 101,487배, ethyl parathion에 대하여 25,914배의 저항성비를 나타내어 parathion이 GSH S-transferase의 기질로 작용하고 있음을 알 수 있었다. 이상의 결과로부터 EF-30 계통에 있어서의 저항성 메카니즘에는 수종의 요인이 관여하여 parathion에 대하여 높은 저항성을 나타냄을 알 수 있었으나, 이들 요인이외에 타 요인의 관여를 배제할 수 없었다.

• 생명과학회지
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• 제28권6호
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• pp.656-662
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• 2018

향상된 인디고이드 생산능력을 갖는 코리네박테리움 유래의 변이 플라빈-함유 모노옥시게나제(cFMO)를 개발하기 위하여, cFMO 효소의 상동성모델을 이용하여 말토오스-결합단백질(MBP)과 융합된 4가지 변이체(F170Y, A210G, A210S, T326S)를 제작하고 그 생화학적 특징을 밝혔다. 정제된 MBP-T326S는 최적 활성을 위하여 야생형보다 고농도의 FAD ($100{\mu}M$)를 요구하며, $100{\mu}M$의 FAD 첨가조건에서 $k_{cat}/K_m$이 3.8배 증가되었다. 인돌 옥시게나제 활성은 야생형의 63-77%를 나타냈다. MBP-T326S는 기질이 존재하지 않을 경우 쓸모없는 NADPH 산화효소 활성이 매우 낮은 수준을 보여주었다(21-24%). T326S이외의 변이 단백질들은 야생형에 비하여 $K_m$은 비슷하며 $k_{cat}/K_m$은 증가하였다. MBP-F170Y와 -A210S 변이단백질은 인돌 옥시게나제 활성이 각각 3.1배, 2.9배 증가하였다. 2.5 g/l의 트립토판을 함유한 LB배지에서 인디고이드 생산을 시험했을 때, 야생형 cFMO를 함유한 대장균은 684 mg/l의 인디고와 104 mg/l의 인디루빈을 생산한 반면, T326S를 함유한 세포는 1,040 mg/l의 인디고와 112 mg/l의 인디루빈을 생산하였다. 이전의 결과인 Methylophaga 유래의 FMO를 발현하는 대장균에서 가장 높은 수준인 920 mg/l의 인디고를 생산한 것과 비교하면, 본 연구결과는 인디고 생산이 13% 높은 수준이였다. 상동성 모델링에 기반한 cFMO의 단백질공학은 인디고이드 생산균을 개발하는데 보다 더 논리적인 전략을 제시하였다.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1997년도 춘계학술대회
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• pp.107-107
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• 1997

Cytochrome P450 enzymes have been intensively investigated in hepatic tissues and several mammalian cell lines. Compared to most studies about cytochrome P450 isozymes in liver in vivo and hepatic, cell lines in vitro, the study of cytochrome P450IA1 in human breast cancer cells could be very important to understand the mechanism of the regulation of CYPIA1 gene expression and cell growth. MCF-7 human breast cancer cells are well characterized to study estrogen and antiestrogen action due to the fact that they contain high level of estrogen receptor and have biological markers characterized. And also MCF-7 cells express high level of arylhydrocarbon hydroxylase activity and human cytochrome P450IA1 cDNA was cloned from MCF-7 cells. Ah receptor was characterized in many breast cancer cell lines and polycyclic aromatic hydrocarbon such as 3-MC induced the expression of CYPIA1 gene and cytochrome P450- dependent monooxygenase activity. We undertook a study to examine the effect of estrogens and other chemicals on the regulation of human CYPIA1 gene expression in MCF-7 cells via RTPCR analysis, that might help us to understand the mechanism of the regulation of CYPIA1 gene expression and MCF-7 cell growth. Expression vector containing the functional 5'-regulatory region of human CYPIA1 fused to the CAT reporter gene was transfected into estrogen receptor positive MCF-T cells or estrogen receptor negative MDA-MB-231 cells. After these cells were treated with various chemicals, RTPCR was carried out to measure both CYPIA1 mRNA and CAT mRNA levels. 1nM 3-MC increased in both P450 and CAT mRNA levels over those of control by two folds in MCF-7 cells but does not in MDA-MB-231 cells. Estrogen or tamoxifen or retinoic acid or chrysin decreased in both P450 and CAT mRNA levels that were induced by 3-MC in MCF-7 when each chemical was administered with 3-MC concomitantly. These results suggested that the level of CYPIA1 gene expression is modulated with estrogen-related molecules and make it possible to speculate that ER is related to CYPIA1 gene expression and cell growth in breast cancer cells. [Supported by grants from the Korean Ministry of Education ]

• 생명과학회지
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• 제20권1호
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• pp.133-141
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• 2010

LED의 간 보호 기능을 연구하기 위하여 $CCl_4$ 및 ethanol로 SD rat에 간독성을 유발한 다음, LED를 처리하였다. LED의 간 기능 보호효과는 간장치료제인 Silymarin과 비교하였다. $CCl_4$로 간 독성을 유발한 경우, LED는간의 항산화효소인 SOD, catalase, GSH peroxidase 효소활성의 항진을 유도하였고, 산화물인 TBARS의 함량을 감소시켰다. 또한 간 손상의 지표인 혈장의 GOT, GPT 및 LDH의 활성을 감소시켰다. Ethanol로 간 독성을 유발한 경우 LED는 간의 SOD, catalase, GSH preoxidase 효소활성 및 GSH 함량을 항진시켰고, 총 cholesterol, triglyceride 및 TBARS의 함량을 감소시켰다. 또한 ethanol 대사에 관여하는 ADH 효소 활성을 증진시켰고, ROS 생성에 관여하는 CYP2E1 효소의 발현을 감소시킴으로써, 혈장의 GOT, GPT 및 LDH 효소활성이 감소되었다. 또한 LED는 DPPH 및 mouse liver mitochondrial system에서 항산화효과를 보였다. 이러한 결과로 미루어 볼 때 LED는 in vitro와 in vivo에서 항산화효과에 의한 간 기능 보호효과를 갖는 것으로 추정된다.