• Title/Summary/Keyword: cytochrome p450

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Oxidative N-Debenzylation of N-Benzyl-N-substituted Benzylamines Catalyzed by Cytochrome P450

  • Kim, Sung-Soo;Lin, Gang;Yang, Ji-Won
    • Bulletin of the Korean Chemical Society
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    • v.25 no.2
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    • pp.249-252
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    • 2004
  • Cytochrome P450 (P450)/$O_2$/NADPH engender electron transfer reaction of N-benzyl-N-substituted benzylamines to yield corresponding radical cation 1 that is simultaneously converted into 2 and 3. Subsequently, expulsion of proton and hydroxylation yielding a-hydroxylamines are followed by formation of benzaldehydes and benzylamines.

The Toxicity of Fthalide in Rats (흰쥐에 있어서 Fthalide의 독성)

  • 김영찬;장영수
    • YAKHAK HOEJI
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    • v.39 no.4
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    • pp.450-460
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    • 1995
  • The acute toxicity of fthalide in rat was studied in vivo by the observations of the changes in hematogram, serological parameters, content of cytochrome p-450, activities of NADPH-cytochrom c reductase, glucose-6-phosphatase, and the contents of cholinesterase and carboxylesterase in liver. Fthabde is a practically non-toxic substance(LD50 is 3.86g/kg), but rats were intoxicated with fthabde at a oral dose of 100 mg/kg for 12 days. WBC were significantly decreased and activities of ALT and LDH, on the cotrary, the content of glucose in serum were slightly increased. Cytochrome p-450 and lipid peroxide in liver were significantly increased in the fthalide-intoxicated rats. The longer administration of fthalide showed further increase of carboxylesterase activity in liver and serum, but decrease of activities of glucose-6-phosphatase and cholinesterase in liver and serum. These results show that fthatide can induce the hepatocellular injury and neurotoxicity.

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POTENT INHIBITION OF HUMAN CYTOCHROME P450 1 ENZYMES BY DIMETHOXYPHENYL VINYL THIOPHENE.

  • Lee, Sangk wang;Kim, Sanghee;Kim, Mie young;Chun, Young-Jin
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2002.05a
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    • pp.92-92
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    • 2002
  • Recently we have reported that various hydroxystilbenes show strong inhibition of human P450 1 activity. A series of synthetic trans-stilbene derivatives were prepared and their inhibitory potentials were evaluated with the bacterial membrane of recombinant human P450 1A1, 1A2 or 1B1 coexpressed with human P450/NADPH-450 reductase to find new candidates for cancer chemoprevention.(omitted)

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High Yield Bacterial Expression and Purification of Active Cytochrome P450 p-coumarate-3-hydroxylase (C3H), the Arabidopsis Membrane Protein (대장균 시스템을 이용한 Arabidopsis 막 단백질 cytochrome P450 p-coumarate-3hydroxylase (C3H) 활성형의 과발현 및 분리정제)

  • Yang, Hee-Jung;Kim, Wan-Yeon;Yun, Young-Ju;Yoon, Ji-Won;Kwon, Tae-Woo;Youn, Hye-Sook;Youn, Bu-Hyun
    • Journal of Life Science
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    • v.19 no.8
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    • pp.1039-1046
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    • 2009
  • The cytochrome P450s (P450s) metabolizing natural products are among the most versatile biological catalysts known in plants, but knowledge of the structural basis for their broad substrate specificity has been limited. The activity of p-coumarate 3-hydroxylase (C3H) is thought to be essential for the biosynthesis of lignin and many other phenylpropanoid pathway products in plants however, all attempts to express and purify the protein corresponding C3H gene have failed. As a result, no conditions suitable for the unambiguous assay of the enzyme are known. The detailed understanding of the mechanism and substrate-specificity of C3Hdemands a method for the production of active protein on the milligram scale. We have developed a bacterial expression and purification system for the plant C3H, which allows for the quick expression and purification of active wild-type C3H via introduction of combinational mutagenesis. The modified cytochrome P450 C3H ($C3H_{mod}$) could be purified in the absence of detergent using immobilized metal affinity chromatography and size exclusion chromatography following extraction from isolated membranes in a high salt buffer and catalytically activated. This method makes the use of isotopic labeling of C3H for NMRstudies and X-ray crystallography practical, and is also applicable to other plant cytochrome P450 proteins.

Purification and Characterization of a Cytochrome P-450 from Pravastatin-Producing Streptomyces sp. Y-110.

  • Park, Joo-Woong;Lee, Joo-Kyung;Kwon, Tae-Jong;Yi, Dong-Hee;Park, Yong-Il;Kang, Sang-Mo
    • Journal of Microbiology and Biotechnology
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    • v.11 no.6
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    • pp.1011-1017
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    • 2001
  • Streptomyces sp. Y-110 cytochrome P-450, induced by the addition of compactin -Na into the culture medium, was purified from the cell extract to apparent homogeniety, mainly by DEAE-Sepharose, hydroxyapatite, and Mono Q column chromatyography. The sepcific activity of purified enzyme on its substrate, compactin-Na, was determined to be 15 nmol of pravastatin per mg protein. The molecular mass of this enzyme on SDS-PAGE was $37{\pm}0.5$ kDa, pI was 4.5, and its CO difference spectrum showed maximum absorption peaks at 452 and 550nm, respectively. The N-terminal amino acid sequence was determined to be Met>Thr>Cys>Thr>Pro>Val>Thr>Val>The>Gly>Ala>Ala>Gly>Gln>Ile>Gly>Tyr>Ala>Leu. Its apparent $K_m$ on compactin-Na was $1.294{\mu}M{\cdot}min^-1,\;and\;V_{max}\;was\;1.028{\mu}M{\cdot}min^-1$. The maximum substrate concentration ($K_s$) for reaction was $270 {\mu}M$and thus $1/[K_s]$ was $3.7{\mu}M$. These physicochemical characteristics and kinetic behavior of this enzyme were compared and shown to be different from those of Streptomyces cytochrome P-450 enzymes reported, suggesting that this enzyme may be an additional member of the Streptomyces cytochrome P-450 family.

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