• Journal of the Korean Wood Science and Technology
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• 제39권6호
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• pp.469-480
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• 2011

본 연구에서는 Ceriporia sp. ZLY-2010을 이용하여 폴리염화비페닐류의 생분해와 효소 시스템간의 상관관계에 대해 알아보고자 하였다. 폴리염화비페닐 동족체 첨가에 따라 단백질 정량 및 manganese peroxidase (MnP)와 laccase의 활성을 비교하였으며, cytochrome P450 monooxygenase의 저해 정도를 평가함으로써 균체 내 효소가 폴리염화비페닐의 생분해에 끼치는 영향을 구명하였다. 단백질 정량 및 균체 외 효소 활성을 측정해 본 결과, 대조구에 비해 폴리염화비페닐 동족체를 첨가한 실험구에서 단백질 농도 및 효소활성이 더 높게 측정되었다. 단백질 농도의 경우, 2,2',4,4',5,5'-hexachlorobiphenyl을 첨가했을 때, 가장 높은 단백질 농도가 측정되었다. 하지만 MnP와 laccase 활성에서는 상대적으로 염소원자가 적게 치환된 2,3',4',5-tetrachlorobiphenyl을 첨가한 실험구에서 높게 나타나는 경향을 보였다. Cytochrome P450 monooxygenase의 저해 정도를 평가한 결과, 2,3',4',5-tetrachlorobiphenyl을 첨가한 실험구의 경우, 배양 1일째, 저해제 1-aminobenzotriazole 0.1 mM에서 2.73%의 분해율을 나타냈으며, 저해제 첨가 시 생분해율이 크게 감소하는 것으로 나타났다. 2,2',4,4',5,5'-hexachlorobiphenyl 역시, 저해제의 존재 하에 20% 내외의 분해율을 보였으며, 이는 대조구에 비해 약 40% 감소한 비율이다.

• 한국환경농학회지
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• 제29권2호
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• pp.184-188
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• 2010

A cyanobacteria species, Anabaena sp. PCC 7120, was tested to assess its biotransformation ability on two widely used insecticides, aldrin and chlorpyrifos-methyl, in the culture medium. The blue-green alga metabolized aldrin mainly to dieldrin by an epoxidation reaction with the participation of cytochrome P450-dependent monooxygenase in the cyanobacteria. The blue-green alga also produced chlorpyrifosmethyl oxon as a primary metabolite from chlorpyrifos-methyl via a desulfuration reaction, presumably conducted by cytochrome P450-dependent monooxygenase. Therefore, two insecticides might be possibly dissipated by cytochrome P450-dependent monooxygenases in the blue-green algae in the contaminated environments.

• Fisheries and Aquatic Sciences
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• 제16권4호
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• pp.261-265
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• 2013

The study was conducted to investigate the responses of the hepatic microsomal cytochrome P450 monooxygenase system in the rock bream Oplegnathus fasciatus after chronic exposure to 0, 1, 2, 4, and $8{\mu}g/L$ tributyltin (TBT) concentrations for 4 weeks. Hepatic cytochrome 450 content and ethoxyresorufin O-deethylation (EROD) activity were found to significantly increase in fish treated with the higher concentration of TBT (${\geq}4{\mu}g/L$); however, no significant changes were observed in penthoxyresorufin O-deethylation (PROD) activity in all treated groups compared to the control group. These findings suggest that exposure to a low TBT concentration (${\geq}4{\mu}g/L$) has the potential to induce cytochrome 450 content and EROD enzyme activity in hepatic tissue in the rock bream.

• Applied Biological Chemistry
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• 제41권4호
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• pp.213-217
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• 1998

An assay for cytochrome P450 monooxygenase activity by determination of the products of organophosphate oxidation via inhibition of acetylcholinesterase was described. Extracts from strains of Oryzaephilus surinamensis selected for resistance to chlorpyrifos-methyl (QVOS 102), fenitrothion (VOS F) and malathion (VOS 3), and a standard susceptible strain VOS 48, were incubated with an organophosphate in the presence of a NADPH-generating system and acetylcholinesterase. The degree of inhibition of the acetylchoinesterase activity was converted to manooxygenase activity using standard curves for the inhibition of acetylcholiesterase by chlorpyrifos-methyl-oxon, fenitrooxon and malaoxan. Activity was detectable in VOS 48 and was present at different increased levels with the different organophosphates in the three resistant strains, suggesting that different forms of P450 might be involved in organophosphate oxidation in these insects. The assays were carried out using crude insect homogenates and much smaller samples of insect material than the standard aldrin to dieldrin assay. It should be possible to use the method for determination of monooxygenase activity in single insert.

• Journal of Microbiology and Biotechnology
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• 제16권6호
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• pp.974-978
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• 2006

The cytochrome P450 monooxygenase from the pikromycin biosynthetic gene cluster in Streptomyces venezuelae, known as PikC, was observed to hydroxylate the unnatural substrate indole to indigo. Furthermore, the site-directed mutagenesis of PikC monooxygenase led to the mutant enzyme F171Q, in which Phe171 was altered to Gln, with enhanced activity for the hydroxylation of indole. From enzyme kinetic studies, F171Q showed an approximately five-fold higher catalytic efficiency compared with the wild-type PikC. Therefore, these results demonstrate the promising application of P450s originating from Streptomyces, normally involved in polyketide biosynthesis, to generate a diverse array of other industrially useful compounds.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.149.3-150
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• 2003

CYP3A4 is the most abundant human CYP and oxidizes a diversity of substrates. including various drugs. steroids. and carcinogens. A variety of metal ions are known to affect microsomal monooxygenase activities. Effects of a series of divalent metal ions on the CYP3A4-catalyzed reaction of reconstituted system containing purified CYP3A4. NADPH-P450 reductase (NPR), and cytochrome b5 (b5) were examined. (omitted)

• Toxicological Research
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• 제5권1호
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• pp.17-25
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• 1989

Chronic adminstraction of morphine to adult male rats has long been known to lower hepatic cytochrome p-450 content and its dependent mixed-function oxidase activity. Following the treatment of adult male rats with morphine, pethidine pentazocine and codeine and also by concomitant adminstration of naloxone activities of microsomal electron transfer in the adult male rats were examined. In present study, the acute treatment of mature male rats with a dose of narcotic drugs higher than that used chronically also reduces their hepatic cytochrome p-450.

• Applied Biological Chemistry
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• 제38권5호
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• pp.463-467
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• 1995

생쥐(Balb/C) 간과 신장의 microsomal cytochrome P-450 효소계에 의한 ${\alpha}$-endosulfan의 시험관내 대사시험을 수행하였다. ${\alpha}$-Endosulfan은 endosulfan lactone(EL), endosulfan hydroxyether(EHE), endosulfan alcohol(EA), endosulfan sulfate(ES), endosulfan ether(EE) 그리고 ${\beta}$-endosulfan(${\beta}$-E) 등으로 대사되었으며 주요 대사산물은 간에서 EL(13.2%) 및 EA(11.5%)이었으며 신장에서 EA(17.4%) 및 EHE(19.3%)이었다. Microsome 배양액중 유기용매 추출성 대사산물은 63.4%이었으며 수용성 대사산물은 37.1%이었다. 수용성 대사산물은 EA(83.9%), EHE(4.5%) 그리고 ES(2.3%)로서 주요 수용성 대사산물은 EA이었다. Piperonyl butoxide는 ${\alpha}$-endosulfan으로부터 EE의 생성을 86%, EA의 생성을 92% 그리고 EHE, EL 및 ES의 생성을 대부분 저해하였다.

• 한국식물학회:학술대회논문집
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• 한국식물학회 2001년도 춘계학술발표대회:발표눈문요지록
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• pp.27-27
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• 2001

• 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.