• Journal of Microbiology and Biotechnology
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• 제14권2호
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• pp.356-365
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• 2004

In analyzing the region of the Amycolatopsis mediterranei S699 chromosome responsible for the biosynthesis of the ansamycin antibiotic rifamycin, we identified a gene, designated orj0, which is located immediately upstream of the rifamycin polyketide synthase (PKS). Orj0 encodes a protein, on the basis of sequence-comparative analysis, that is similar to several cytochrome P450 monooxygenases from different sources. The rifamycin producer, A. mediterranei, predominantly produces rifamycin B from its macrocyclic intermediate, proansamycin X, through dehydrogenation and hydroxylation steps. However, an A. mediterranei strain, deleted in orj0 by gene replacement, no longer produced rifamycin B. Furthermore, a versatile replicative vector in A. mediterranei was constructed and rifamycin B production was restored in a complementation experiment of orj0 using this novel vector. These consecutive results verified that the arf0 protein, which is a P450 hydroxylase, is required for the production of rifamycin B in A. mediterranei.

• 농약과학회지
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• 제14권3호
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• pp.247-254
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• 2010

2000년 12월 경북 칠곡의 장미재배지에서 점박이응애를 채집하여 10년 동안 bifenazate로 도태시켜 855.9배의 저항성 계통을 얻었다. 이 계통의 성충에 대한 8종 살비제의 교차저항성 유무를 조사한 결과, acequinocyl에 614.0배의 높은 교차저항성을 나타내었고, chlorfenapyr는 9.1배의 낮은 교차저항성을 나타내었다. 한편 fenazaquin(0.3배)와 fenpyroximate(0.1배)는 역상관 교차저항성을 나타내었다. 청주, 강진, 충주에서 채집한 점박이응애의 bifienazate 저항성을 확인해 본 결과, 청주와 충주의 개체군은 각각 5.5배, 21.8배의 낮은 저항성을 보였고 강진 개체군은 964.5배의 높은 저항성을 나타내었다. 또한 esterases(EST), glutathione S-transferase(GST)과 cytochrome $P_{450}$-dependent monooxygenase($P_{450}$)의 효소활성을 조사한 결과, bifenazate 저항성 점박이응애의 $P_{450}$의 활성이 감수성계통에 비해 1.6배 높은 것으로 나타났다. 감수성계통과 저항성계통의 미토콘드리아 cytochrome b의 DNA염기서열과 아미노산을 비교한 결과, G126S의 점 돌연변이(point mutation)를 확인하였고 bifenazate 약제에 높은 저항성을 보이는 강진 개체군에서도 G126S의 점 돌연변이를 확인하였다.

• 한국연초학회지
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• 제20권1호
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• pp.99-107
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• 1998

Numerous studies have demonstrated a negative association between cigarette smoking and Parkinson's disease. The present study was undertaken to investigate whether chronic exposure of mice to cigarette smoke a(footed the metabolism of 1-methyl-1113,6-tetrahydro-pyridine (MPTP) by cytochrome P4SO (P-450) or flavin-containing monooxygenase (FMO) in the hepatic microsomes of C57BL6/J mice. Adult male C57BL6/J mice were exposed to mainstream smoke generated from 15 cigarettes for 10 min a day and 5 day per week for 6 weeks. MPTP (10 mg/kg body weight) was administered to mice by subcutaneous injection for 6 consecutive days. Microsolnal P-450 content was increased by MPTP, smoke exposure, or both, but NADPH cytochrome P-450 reductase activity was rather decreased by the same treatments. The activities of benzo(a)pyrene hydroxylase, 7-ethoxycoumarin O-deethylase and ethoxyresorufin O-deethylase were significantly increased by the exposure of cigarette smoke, but were not or little affected by MPTP treatment. Benzphetamine N-demethylase activity was not affected either by MPTP treatment or by cigarette smoke exposure, but it was significantly increased by the combined MPTP treatment with cigarette smoke exposure, showing their synergic effect for the induction of the enzyme activity. Interestingly, in vitro studies of hepatic FMO and P-450 system both O-oxygenation and N-demethylation of MPTP were increased in the smoke-exposed or in the MPTP-treated mice. These results suggest that the enhancement in the N-demethylation as well as O-deethylation of P-450 system and in the N-oxygenation of FMO activity by cigarette smoke exposure in mouse liver may contribute to attenuating the neurotoxic effects of MPTP on the nigrostriatal dopaminergic neurons.

• Toxicological Research
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• 제3권1호
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• pp.1-8
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• 1987

In vitro induction of cytochrome 450 associated monooxygenase activities by phenobarbital (PB) and 3-methylcholanthrene (MC) was investigated in primary cultures of adult rat hepatocytes. PB and MC were added to the culture 24 hr after the initial plating of hepatocytes. A signiftcant increase of the activities of 7-ethoxycoumarin 0-deethylase and aryl hydrocarbon hydroxylase were observed in MC and PB treated culture. MC caused about 500% induction of the initial oxidation rates of both enzymes in 48 hr. However the PB maintained both enzyme activities close to the level of freshly isolated hepatocytes. Biphenyl 4-hydroxylase and aminopyrine N-demethylase activities were also induced by MC and PB. But the level of induction was less than that occuring with 7-ethoxycoumarin 0-deethylase and aryl hydrocarbon hydroxylase. When aflatoxin $B_1$ was added to the hepatocyte cultures which have been treated with MC or PB, it caused a significant increase of the unscheduled DNA synthesis at higher dose of aflatoxin $B_1$ as compared to those of untreated control hepatocyte cultures. The results suggest that microsomal enzyme activities can be selectively controlled preferably in hepatocyte cultures by the in vitro induction method. This principle may be useful for studying the metabolism and other toxicological studies.

• Toxicological Research
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• 제27권1호
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• pp.25-29
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• 2011

The cytochrome P450 (P450, CYP) are the superfamily of heme-containing monooxygenase enzymes, found throughout all nature including mammals, plants, and microorganisms. Mammalian P450 enzymes are involved in oxidative metabolism of a wide range of endo- and exogenous chemicals. Especially P450s involved in drug metabolisms are important for drug efficacy and polymorphisms of P450s in individuals reflect differences of drug responses between people. To study the functional differences of CYP2A6, CYP2D6, and CYP4A11 variants, we cloned the four CYP2A6, three CYP2D6, and three CYP4A11 variants, which were found in Korean populations, in mammalian expression vector pcDNA by PCR and examined their expressions in COS-7 mammalian cells using immunoblots using P450 specific polyclonal antibodies. Three of four CYP2A6, two of three CYP4A11, and two of three CYP2D6 variants showed expressions in COS-7 cells but the relative levels of expressions are remarkably different in those of each variants. Our findings may help to study and explain the differences between functions of CYP variants and drug responses in Korean populations.

• 한국약용작물학회지
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• 제15권6호
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• pp.437-443
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• 2007

홍삼의 물추출물을 장기간 흰쥐에 급여했을 때 흰쥐 간의 이물질대사효소 활성도 유도에 미치는 영향을 조사하였다. 홍삼 물추출물의 급여농도는 25 mg/kg body weight이었으며, 간의 이물질대사효소 유도제는 항경련제 PB (80 mg/kg)와 발암제 3-MC (20 mg/kg)을 사용하였다. 간에서 이물질대사에 관여하는 cytochrome P-450의 함량, cytochrome P-450 dependent monooxygenase인 ECOD와 BPDM, cytochrome P-450 reductase와 GST의 활성도는 PB와 3-MC 투여에 의해서 대조군과 홍삼투여군 모두 크게 증가되었다. 흰쥐의 나이가 3개월에서는 두 유도제를 투여했을 때 이물질대사효소의 활성은 대조군이 인삼투여군에 비해 상대적으로 더 많이 유도되었다. 그러나 12개월에서는 두 시험군 모두 유도정도가 감소하였으나 홍삼투여군은 그 활성도 감소정도가 대조군에 비해 상대적으로 크지 않았다. 한편 두 그룹 모두 이물질대사 효소 중 cytochrome $B_5$ 함량과 cytochrome $b_5$ reductase의 활성도는 PB와 3-MC 투여에 의해서 뚜렷한 차이를 보이지 않았다. 따라서 이러한 결과는 흰쥐에 홍삼의 장기간 급여는 간에서 효소유도제의 이물질대사효소유도 정도를 조절하여 무독화에 기여할 수 있다는 것을 의미한다.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.376.2-377
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• 2002

Some of the dammarane-type saponins. ginsenosides of Panax ginseng C.A. Meyer (Araliaceae) are now well established as a potent chemotherapeutic agent against a wide variety of aliments. Its various pharmacological and biological activities have been thoroughly reviewed (S. Shibata, 2001). The limited supply of the drug from the original source. the hairy root of the Panax ginseng promoted intense efforts to develop alternate sources and means of production. (omitted)

• Journal of Microbiology and Biotechnology
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• 제30권5호
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• pp.777-784
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• 2020

Self-sufficient P450s, due to their fused nature, are the most effective tools for electron transfer to activate C-H bonds. They catalyze the oxygenation of fatty acids at different omega positions. Here, two new, self-sufficient cytochrome P450s, named 'CYP102A15 and CYP102A170,' from polar Bacillus sp. PAMC 25034 and Paenibacillus sp. PAMC 22724,respectively, were cloned and expressed in E. coli. The genes are homologues of CYP102A1 from Bacillus megaterium. They catalyzed the hydroxylation of both saturated and unsaturated fatty acids ranging in length from C₁₂-C₂₀, with a moderately diverse profile compared to other members of the CYP102A subfamily. CYP102A15 exhibited the highest activity toward linoleic acid with K_m 15.3 μM, and CYP102A170 showed higher activity toward myristic acid with Km 17.4 μM. CYP10A170 also hydroxylated the Eicosapentaenoic acid at ω-1 position only. Various kinetic parameters of both monooxygenases were also determined.

• Archives of Pharmacal Research
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• 제26권5호
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• pp.394-404
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• 2003

Certain polycyclic aromatic hydrocarbons (PAHs) have been reported to induce cytochrome P450 (CYP) 1A1 and 1A2. In the present study, the effects of six well-known PAHs, such as benzo[a]pyrene, benz[a]anthracene, dibenz[a,h]anthracene, chrysene, benzo[k]fluorancene and benzo[b]fluorancene, on the activities of hepatic and pulmonary CYP enzymes were investigated in male ICR mice. When mice were treated intraperitoneally with 3, 10 and 30 mg/kg of individual PAHs for 3 consecutive days, the activities of ethoxyresorufin- and methoxyresorufin-Ο-dealkylases were significantly and differentially induced in both liver and lung. Moreover, other CYP isozyme-associated monooxygenase activities were also induced significantly in liver and lung with characteristic induction profiles. Our present results suggest that individual PAHs might have inductive effects on CYP isozymes, and that the characteristic inductive effects of individual PAHs on certain CYP isozymes would be developed as a marker for determining exposure to certain PAHs.

• Journal of Microbiology and Biotechnology
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• 제29권1호
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• pp.44-54
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• 2019

Geldanamycin and its derivatives, inhibitors of heat shock protein 90, are considered potent anticancer drugs, although their biosynthetic pathways have not yet been fully elucidated. The key step of conversion of 4,5-dihydrogeldanamycin to geldanamycin was expected to catalyze by a P450 monooxygenase, Gel16. The adequate bioconversions by cytochrome P450 mostly rely upon its interaction with redox partners. Several ferredoxin and ferredoxin reductases are available in the genome of certain organisms, but only a few suitable partners can operate in full efficiency. In this study, we have expressed cytochrome P450 gel16 in Escherichia coli and performed an in vitro assay using 4,5-dihydrogeldanamycin as a substrate. We demonstrated that the in silico method can be applicable for the efficient mining of convenient endogenous redox partners (9 ferredoxins and 6 ferredoxin reductases) against CYP Gel16 from Streptomyces hygroscopicus. The distances for ligand FDX4-FDR6 were found to be $9.384{\AA}$. Similarly, the binding energy between Gel16-FDX4 and FDX4-FDR6 were -611.88 kcal/mol and -834.48 kcal/mol, respectively, suggesting the lowest distance and binding energy rather than other redox partners. These findings suggest that the best redox partners of Gel16 could be NADPH ${\rightarrow}$ FDR6 ${\rightarrow}$ FDX4 ${\rightarrow}$ Gel16.