• Applied Biological Chemistry
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• 제39권1호
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• pp.77-83
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• 1996

이스라엘 잉어에 있어서 carbamate계 살충제 carbofuran의 독성에 미치는 phenobarbital sodium(PB) 또는 3-methylcholanthrene (3-MC)의 영향과 작용기작을 효소적 측면에서 구명할 목적으로 carbofuran과 PB나 3-MC를 이스라엘 잉어에 각 조합으로 처리하여 독성경감 효과를 조사하였고, 공시한 농약과 PB나 MC가 acetylcholinesterase(AChE), glutathione S-transferase(GST), UDP-glucuronosyltransferase(UDPGT) 및 cytochrome P-450-dependent monooxygenase(monooxygenase)의 효소활성에 미치는 영향을 조사하기 위하여 carbofuran과 PB나 3-MC를 각각 조합으로 처리한 후 경시적으로 이스라엘 잉어의 각 효소들의 상대활성도를 조사하였다. PB와 3-MC만 투여한 실험군에서 이스라엘 잉어의 생존수는 무처리군과 동일하였고 살충제만 처리한 실험군의 이스라엘 잉어 생존수는 처리농도가 증가하면서 감소되었으나, PB나 3-MC와 살충제를 조합처리한 실험군에서는 살충제만 처리한 실힘군에 비하여 매우 높은 생존율을 나타낸 것으로 보아 해독효과가 인정 되었다. 효소활성(in vivo)은 AChE의 경우 carbofuran 0.95 ppm만을 처리한 실험군에서는 24시간내내 각 조사시기마다 무처리군에 비해 40% 이상의 활성저해를 보였으나 carbofuran과 PB 및 3-MC를 조합처리한 실험군에서는 효소활성이 초기에 감소하다가 서서히 증가하여 24시간후에는 무처리군과 비슷한 수준을 나타냈고, GST의 경우 carbofuran만을 처리한 실험군에서는 초기에 약 20% 이상의 활성저해를 보였으나 carbofuran과 PB나 3-MC를 조합처리한 실험군에서는 약제처리 1시간 후 부터 무처리군에 비해 효소활성이 20% 이상 증가하였다. UDPGT와 monooxygenase의 효소활성은 carbofuran과 PB나 3-MC를 조합처리한 실험에서 처리 $6{\sim}12$시간 후에는 carbofuran 처리군에 비해 효소활성이 $4{\sim}8$배 이상 급격히 높아졌다. 이상의 결과에서 PB 및 3-MC처리가 이들 효소의 활성을 유도함으로써 carbofuran의 독성으로 부터 이스라엘 잉어를 보호 하는데 관여한 것으로 보인다.

• Toxicological Research
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• 제13권4호
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• pp.385-391
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• 1997

Inductive effects of cytochrome P450 2B1 by $\alpha$- and $\beta$-ionone were characterized in individual liver lobes of male Sprague Dawley rats. When rats were administered ionones orally at 100, 300, and 600 mg/kg for 24 hr, cytochrome P450 2B1 was induced dose-dependently in liver S-9 fractions as measured by P450 2B-specific monooxygenases and Western immunoblotting. The activity of P450 1A- and P450 2B-specific monooxygenases was differentially expressed in each lobe of normal liver. In addition, the monooxygenase activity was induced by $\alpha$- and $\beta$-ionone with different potency in each lobe of the liver. Our present results indicate that the different induction of P450s by $\alpha$- and $\beta$-ionone in each lobe may explain different susceptibilities of rat liver lobes to certain hepatotoxicants which require metabolic activation for their toxicity and that $\alpha$- and $\beta$-ionone may be useful model inducers of P450 2B1 in studying the toxic mechanism of certain toxicants which may require the metabolic activation by P450.

• Journal of Microbiology and Biotechnology
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• 제26권12호
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• pp.2076-2086
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• 2016

Fungal cytochrome P450 (CYP) enzymes catalyze versatile monooxygenase reactions and play a major role in fungal adaptations owing to their essential roles in the production avoid metabolites critical for pathogenesis, detoxification of xenobiotics, and exploitation avoid substrates. Although fungal CYP-dependent biotransformation for the selective oxidation avoid organic compounds in yeast system is advantageous, it often suffers from a shortage avoid intracellular NADPH. In this study, we aimed to investigate the use of bacterial glucose dehydrogenase (GDH) for the intracellular electron regeneration of fungal CYP monooxygenase in a yeast reconstituted system. The benzoate hydroxylase FoCYP53A19 and its homologous redox partner FoCPR from Fusarium oxysporum were co-expressed with the BsGDH from Bacillus subtilis in Saccharomyces cerevisiae for heterologous expression and biotransformations. We attempted to optimize several bottlenecks concerning the efficiency of fungal CYP-mediated whole-cell-biotransformation to enhance the conversion. The catalytic performance of the intracellular NADPH regeneration system facilitated the hydroxylation of benzoic acid to 4-hydroxybenzoic acid with high conversion in the resting-cell reaction. The FoCYP53A19+FoCPR+BsGDH reconstituted system produced 0.47 mM 4-hydroxybenzoic acid (94% conversion) in the resting-cell biotransformations performed in 50 mM phosphate buffer (pH 6.0) containing 0.5 mM benzoic acid and 0.25% glucose for 24 h at $30^{\circ}C$. The "coupled-enzyme" system can certainly improve the overall performance of NADPH-dependent whole-cell biotransformations in a yeast system.

• Archives of Pharmacal Research
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• 제16권2호
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• pp.89-93
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• 1993

Incubation of $S(-)-^3H$-nicotine with rabbit lung microsomes in the presence of dioxygen and NADPH results in the formation of metabolities that bind covalently to microsomal macro-molecules. The addition of cytochrome P-450 monooxygenase inhibitors, $\alpha$-methylbenzyl ami-nobenzotriazole and aroclor 1260, inhibited both (S)-nicotine metabolism and covalent binding. The relative rates of oxidation of nicotine $\Delta^{1',5'}$ iminium ion to continine indicates that lung $100,000\times{g}$ supematant catalyzed this oxidation approximately 18 times slower than that of liver system based on mg of protein, and increased covalent interactions. Since than that of liver system based on mg of protein, nd increased covalent interactions. Since the activity of lung iminium oxidase appears much lowr than the liver, it is tempting to speculate that localized concentrations of nicotine $\Delta^{1',5'}$ iminium ion in the lung will survive for a longer period of time. These results support that cytochrome P-450 catalyzed oxidation of nicotine leads to the formation of reactive nad electrophilic intemediates capable of chemical interactions with biomacromolecules.

• Bulletin of the Korean Chemical Society
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• 제19권8호
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• pp.875-878
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• 1998

• Journal of Microbiology and Biotechnology
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• 제9권2호
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• pp.147-149
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• 1999

Biotransformation of exogenous (-)-(4R)-isopiperitenone in cell suspension cultures of Mentha piperita resulted in oxidized products, with (-)-7-hydroxyisopiperitenone being the major compound. The mass of products obtained $unde^{18}O_2$, atmosphere was two units higher than that under normal atmosphere. The biotransformation was inhibited by several cytochrome P450-specific inhibitors as well as by carbon monoxide. Carbon monooxide inhibition was substantially overcome by irradiation of cells with blue light including light at 450nm wavelength. These results suggested that a cytochrome P450-type monooxygenase was involved in the biotransformation.

• 대한예방의학회:학술대회논문집
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• 대한예방의학회 1995년도 제47차 추계 학술대회 연제집
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• pp.349-350
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• 1995

• 한국독성학회:학술대회논문집
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• 한국독성학회 2002년도 Current Trends in Toxicological Sciences
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• pp.73-73
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• 2002

Thioacetamide has been known to cause immune suppression. The object of the present study is to investigate the role of metabolic activation by flavin- containing monooxygenases (FMO) in thioacetamide-induced immune response. To determine whether the metabolites of thioacetamide produced by FMO causes the immunosuppression, methimazole (MMI), an FMO inhibitor, was used to block the FMO pathway.(omitted)

• 한국수산과학회지
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• 제34권3호
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• pp.194-198
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• 2001

PCBs의 경구 투여에 의한 틸라피아, Oreochromis niloticus의 간 cytochrome P450 효소계의 변화를 30일간 관찰하였다. 30일 동안 PCBs 0.05, 0.25 및 0.50mg/kg을 투여했을 때, HSI는 각각 1.81, 1.72 및 $1.54\%$ 감소하였으나, 유의한 차이는 인정되지 않았다. PCBs 0.05mg/kg에 노출된 간 cytochrome P450 농도는 30일째 대조구에 비해 1.4배 유의한 증가를 나타냈고, 0.25mg/kg 이상에서는 실험 20일 이후부터 유의적으로 증가하였다. EROD 활성도는 PCBs 0.05 mg/kg에서 실험 30일째부터 유의하게 증가하여 약 8배 높게 나타났다. 또한, PCBs 0.25mg/kg이상에서는 실험 20일째부터 유의하게 증가하여 30일째부터는 각각 18 및 22배의 증가를 나타냈다. PROD는 PCBs $0.05\~0.50mg/kg$에 노출시킨 개체에서 $0.78\~1.93$pmole/mg protein이 측정되어 대조구에 비해 뚜렷한 변화는 관찰되지 않았다. 이상의 결과는 자연 수역에서 PCBs의 잔류에 따라 먹이를 통해 틸라피아의 체내에 적어도 0.05 mg/kg 이상이 30일간 이상 계속적으로 유입될 경우에 간 cytochrome P450농도 및 EROD 활성도는 증가될 것으로 추정된다.

• Biomolecules & Therapeutics
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• 제17권2호
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• pp.156-161
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• 2009

The human cytochrome P450 4A11 is the major monooxygenase to oxidize the fatty acids and arachidonic acid. The production of 20-hydroxyeicosatetraenoic acid by P450 4A11 has been implicated in the regulation of vascular tone and blood pressure. Oxidation reaction by P450 4A11 requires its reduction partners, NADPH-P450 reductase (NPR). We report the functional expression in Escherichia coli of bicistronic constructs consisting of P450 4A11 encoded by the first cistron and the electron donor protein, NPR by the second. Typical P450 expression levels of wild type and several N-terminal modified mutants was observed in culture media and prepared membrane fractions. The expression of functional NPR in the constructed P450 4A11: NPR bicistronic system was clearly verified by reduction of nitroblue tetrazolium. Membrane preparation containing P450 4A11 and NPR efficiently oxidized lauric acid mainly to $\omega$-hydroxylauric acid. Bicistronic coexpression of P450 4A11 and NPR in E. coli cells can be extended toward identification of novel drug metabolites or therapeutic agents involved in P450 4A11 dependent signal pathways.