• Title/Summary/Keyword: cytochrome P450 monooxygenases

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Activity of Mixed Function Oxidase in a few Insect Species in Relation to Their Food Source (먹이종류에 따른 몇가지 곤충의 MFO활성 비교)

  • 이정호;부경생
    • Korean journal of applied entomology
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    • v.32 no.3
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    • pp.291-299
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    • 1993
  • Midgut tissues from 4 insect specIes were exammed for the activity of cytochrome P-450 monooxygenases, a major enzyme involved in chemical detoxification. When Helicoverpa assulta larvae were reared on an artificial d;et, the specific activity of the midgut cytochrome P-450 monooxygenases (MFO) was :3 times higher than that of the fat body, The specific activity of the midgut cytochrome P-450 monooxygenases was higher in H. assul/a larvae when reared on Nicotiana tabacum leaves than when on CapsIcum annuum fruits or an artificial diet. In the case of Hyphantria cunea larvae, Tilia megaphyllo leaves were the best in inducing midgut cytochrome P-450 monooxygenases activity. When larvae of H. assulta, Spodoptera exigua, H. cunea and Spodoptera litura were reared on their own artificial diet, the highest activity was seen in S. exigua larvae which is a polyphagous and insecticide-resistant strain.

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Comparative effects of nicotine and diazinon on larval mortality and activity of cytochrome P-450 monooxygenases in Helicoverpa assulta and Spodoptera exigua (담배나방과 파밤나방의 유충사망률과 cytochrome P-450 monooxygenases의 활성에 미치는 니코틴과 다이아지논의 영향)

  • 이정호;부경생
    • Korean journal of applied entomology
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    • v.32 no.2
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    • pp.225-235
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    • 1993
  • This study was carried out to investigate effects of diazinon, an organophosphate, and nicotine, a plant~originated toxic chemical, on larval mortality and activity of cytochrome P-45D monooxygenases, a major detoxifwation enzyme system, in Helicoverpa assulta and Spodoptera exigua. Diazinon treatment gave a higher mortaliLy to H. assulta larvae than S. exigua larvae. In contrast to the case of diazinon, nicotine caused a higher mortahty to S. exigua than to H. assulla larvae. It was partly due to the fact that nicotine induced the actiVIty of midgut cytochrome P-450 monooxygenases (MFO) more than diazinon did in If assulta larvae. When If. aSSlllta larvae were reared on their host p\am. NicotwlIa tuoocum leaves, other componentS were mostly metabolized with the exception of dietary nicotine.

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Induction of Cytochrome P450 by Ionones in Liver Lobes of Sprague Dawley Rats (Ionone류에 의한 랫드의 간엽별 cytochrome P450 유도 특성에 관한 연구)

  • 구희경;정태천;천영진;윤철호;노정구;최인경
    • Toxicological Research
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    • v.13 no.4
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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.

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ROLE OF METABOLISM BY FLAVIN-CONTAINING MONOOXYGENASE IN THIOACETAMIDE-INDUCED IMMUNOSUPPRESSION

  • Woo S. Koh;Lee, Jeong W.;Tae C. Jeong
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2002.05a
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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)

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Biotransformation of Aldrin and Chlorpyrifos-methyl by Anabaena sp. PCC 7120

  • Park, Byeoung-Soo;Lee, Sung-Eun
    • Korean Journal of Environmental Agriculture
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    • v.29 no.2
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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.

Characterization of Two Self-Sufficient Monooxygenases, CYP102A15 and CYP102A170, as Long-Chain Fatty Acid Hydroxylases

  • Rimal, Hemraj;Lee, Woo-Haeng;Kim, Ki-Hwa;Park, Hyun;Oh, Tae-Jin
    • Journal of Microbiology and Biotechnology
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    • v.30 no.5
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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 Km 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.

Cytochrome P450 monooxygenase analysis in free-living and symbiotic microalgae Coccomyxa sp. C-169 and Chlorella sp. NC64A

  • Mthakathi, Ntsane Trevor;Kgosiemang, Ipeleng Kopano Rosinah;Chen, Wanping;Mohlatsane, Molikeng Eric;Mojahi, Thebeyapelo Jacob;Yu, Jae-Hyuk;Mashele, Samson Sitheni;Syed, Khajamohiddin
    • ALGAE
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    • v.30 no.3
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    • pp.233-239
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    • 2015
  • Microalgae research is gaining momentum because of their potential biotechnological applications, including the generation of biofuels. Genome sequencing analysis of two model microalgal species, polar free-living Coccomyxa sp. C-169 and symbiotic Chlorella sp. NC64A, revealed insights into the factors responsible for their lifestyle and unravelled biotechnologically valuable proteins. However, genome sequence analysis under-explored cytochrome P450 monooxygenases (P450s), heme-thiolate proteins ubiquitously present in species belonging to different biological kingdoms. In this study we performed genome data-mining, annotation and comparative analysis of P450s in these two model algal species. Sixty-nine P450s were found in two algal species. Coccomyxa sp. showed 40 P450s and Chlorella sp. showed 29 P450s in their genome. Sixty-eight P450s (>100 amino acid in length) were grouped into 32 P450 families and 46 P450 subfamilies. Among the P450 families, 27 P450 families were novel and not found in other biological kingdoms. The new P450 families are CYP745-CYP747, CYP845-CYP863, and CYP904-CYP908. Five P450 families, CYP51, CYP97, CYP710, CYP745, and CYP746, were commonly found between two algal species and 16 and 11 P450 families were unique to Coccomyxa sp. and Chlorella sp. Synteny analysis and gene-structure analysis revealed P450 duplications in both species. Functional analysis based on homolog P450s suggested that CYP51 and CYP710 family members are involved in membrane ergosterol biosynthesis. CYP55 and CYP97 family members are involved in nitric oxide reduction and biosynthesis of carotenoids. This is the first report on comparative analysis of P450s in the microalgal species Coccomyxa sp. C-169 and Chlorella sp. NC64A.