• Title, Summary, Keyword: epoxide hydrolase

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Evaluation of Microbial Epoxide Hydrolase Activity Based on Colorimetric Assay Using 4-(p-nitrobenzyl) Pyridine (4-(p-Nitrobenzyl)pyridine의 색깔반응을 이용한 미생물 epoxide hydrolase의 활성 평가)

  • Kim Hee Sook;Lee Eun Yeol
    • Journal of Life Science
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    • v.15 no.3
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    • pp.332-336
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    • 2005
  • Epoxide hydrolase activities of various microbial cells were analyzed by colorimetric assay based on alkylation of epoxides with 4-(p-nitrobenzyl)pyridine (NBP). The epoxide hydrolase activity was determined by measuring the decrease of color intensity at 560 nm due to the decrease of styrene oxide substrate by epoxide hydrolase-catalyzed hydrolysis reaction. The experimental conditions of NBP colorimetric assay were optimized for the efficient measurement of epoxide hydrolase activities from various microbial cells.

Development of Soluble Epoxide Hydrolase Inhibitor Screening Methods for Discovery of Drug Candidate in Cardiovascular Diseases (심혈관계 질환 치료제 후보물질 발굴을 위한 Soluble Epoxide Hydrolase 억제평가 방법 개발)

  • Lee, Gwan-Ho;Kim, Bong-Hee;Kim, Sang-Kyum
    • YAKHAK HOEJI
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    • v.56 no.1
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    • pp.42-47
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    • 2012
  • Soluble epoxide hydrolase (sEH) is a metabolic regulator of epoxyeicosatrienoic acids (EETs). EETs have many beneficial effects, vasodilation, anti-diabetes, anti-inflammation, cardiovascular protection, renal protection. Therefore, selective sEH inhibitors have a potential for treating these diseases. In the present study, screening methods for sEH inhibitors using PHOME ((3-phenyl-oxiranyl)-acetic acid cyano-(6-methoxynaphthalen-2-yl)-methyl ester) and 14-15-EET as substrates were established. To determine selectivity, microsomal epoxide hydrolase (mEH) inhibition assay was also developed using styrene oxide as a substrate of microsomal epoxide hydrolase. Our results obtained from 12-[[(tricyclo[3.3.1.13,7]dec-1-ylamino)carbonyl]amino]-dodecanoic acid (AUDA) used as a positive sEH inhibitor and valpromide used as a positive mEH inhibitor showed that these methods are useful for discovery of drug candidates.

Protective Effect of Ginseng on Bromobenzene-Induced Hepatotoxicity in Mice (Mouse Liver의 Cytosolic Epoxide Hydrolase 활성도에 미치는 인삼 사포닌 분획의 영향)

  • Huh Keun;Jang Byung-Su;Park Jong-Min
    • Proceedings of the Ginseng society Conference
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    • pp.39-42
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    • 1988
  • We have studied the mechanism by examing the effect of ginseng on the epoxide hydrolase which is catabolized the reactive intermetabolite of bromobenzene. and bromobenzene-induced hepatotoxicity. It was observed that ginseng saponin fraction protects against bromobenzene-induced hepatotoxicity in mice as evidenced 1. increased the epoxide hydrolase activity. 2. lower serum transaminase activity. 3. decreased the formation of lipid peroxide. These results suggested that the inducing effect of ginseng on the epoxide hydrolase is believed to be a possible detoxication mechanism for the bromobenzene toxicity in mice.

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Optimization of Microbial Cell-Based Spectrometric Assay for the Analysis of Epoxide Hydrolase Activity (미생물 세포 기반의 에폭사이드 가수분해효소 활성 측정을 위한 분광학적 분석법 최적화)

  • Kim Hee Sook;Lee Eun Yeol
    • Journal of Life Science
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    • v.15 no.1
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    • pp.136-140
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    • 2005
  • Microbial cell-based UV spectrometric assay for the quantitative measurement of epoxide hydrolase activity was evaluated and optimized for the efficient screening of whole cell activity of novel epoxide hydrolase. Epoxide hydrolase activity was determined by measuring the increase of the oxidized product, benzaldehyde. The effects of the concentrations of phenyl-1,2-ethanediol, sodium metaperiodate and cells were optimized for epoxide hydrolase-catalyzed hydrolysis of styrene oxide. The relevant kinetic parameters of Km and $V_{max}$ for the hydrolysis of (R)-styrene oxide by Rhodotorula glutinis were determined from Lineweaver-Burk plot as 41.2 nmol/min$\cdot$mg dcw and 7.5 mM respectively, and coincided well with those from GC analysis.

Development of Asymmetric Resolution System for the Production of Chiral Styrene Oxide by Microbial Epoxide Hydrolase (미생물 유래의 Epoxide Hydrolase를 이용한 Chiral Styrene Oxide 생산용 비대칭 광학분할시스템개발)

  • 이지원;윤여준;이은열
    • Journal of Life Science
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    • v.12 no.5
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    • pp.584-588
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    • 2002
  • Asymmetric enantioselective resolution system using epoxide hydrolase activity of Aspergillus niger LK was developed and operated for the production of optically pure styrene oxide. Two-phase hollow-fiber reactor system was employed for the enhanced solubility of racemic styrene oxide in organic phase and protection of epoxide hydrolase activity in aqueous phase. For the removal of phenyl-1,2-ethandiol, the inhibitor of epoxide hydrolase, cascade hollow-fiber reactor system was also developed. Chiral (S)-styrene oxide (39 mM in dodecane) could be asymmetrically resolved with high enantiopurity (> 99% ee) using these reactor system.

Hepatoprotective Activities of Rosa davurica Root Extract in Rats Intoxicated with Bromobenzene (브로모벤젠으로 유도된 간독성 흰쥐에서 생열귀나무 뿌리의 간보호활성)

  • Park, Jong-Cheol;Hur, Jong-Moon;Hwang, Young-Hee;Choi, Myeong-Rak;Kim, Suk-Nam;Choi, Jong-Won
    • Journal of Life Science
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    • v.13 no.2
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    • pp.230-235
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    • 2003
  • To investigate hepatoprotective activities of the root extract of Rosa davurica, the activities of hepatic enzymes, aminopyrine N-demethylase, aniline hydroxylase, glutathione S-transferase and epoxide hydrolase in rats intoxicated with bromobenzene were studied. Pretreatment with the methanol extract from the roots of Rosa davurica did not show any significant effects on the increases of the activities of aminopyrine N-demethylase and aniline hydroxylase, enzymes forming toxic epoxide by bromobenzene. There was no change in glutathione S-transferase activity by Rosa davurica. However, the activity of epoxide hydrolase, and epoxide-removing enzyme, was increased 33% by the administration of 500 mg/kg of the methanol extract. From the results, the protection of Rosa davurica against bromobenzene-induced hepatotoxicity is thought to be via enhancing the activity of epoxide hydrolase, an enzyme removing toxic epoxide rather than through epoxide-producing system.

Molecular Characterization of Epoxide Hydrolase from Aspergillus niger LK using Phylogenetic Analysis (진화적 유연관계 분석을 통한 Aspergillus niger LK의 Epoxide Hydrolase의 특성분석)

  • 김희숙;이은열;이수정;이지원
    • KSBB Journal
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    • v.19 no.1
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    • pp.42-49
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    • 2004
  • A gene coding for epoxide hydrolase (EH) of Aspergillus niger LK, a fungus possessing the enantioselective hydrolysis activity for racemic epoxides, was characterized by phylogenetic analysis. The deduced protein of A. niger LK epoxide hydrolase shares significant sequence similarity with several bacterial EHs and mammalian microsomal EHs (mEH) and belongs to the a/${\beta}$ hydrolase fold family. EH from A. niger LK had 90.6% identity with 3D crystal structure of lqo7 in Protein Data Bank. Sequence comparison with other source EHs suggested that Asp$\^$l92/, Asp$\^$374/ and His$\^$374/ constituted the catalytic triad. Based on the multiple sequence comparison of the functional and structural domain sequence, the phylogenetic tree between relevant epoxide hydrolases from various species were reconstructed by using Neighbor-Joining method. Genetic distances were so far as 1.841-2.682 but characteristic oxyanion hole and catalytic triad were highly conserved, which means they have diverged from a common ancestor.

Biocatalytic Preparation of Chiral Epichlorohydrins Using Recombinant Pichia pastoris Expressing Epoxide Hydrolase of Rhodotorula glutinis

  • Kim, Hee-Sook;Lee, Jae-Hwa;Park, Sunghoon;Lee, Eun-Yeol
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.9 no.1
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    • pp.62-64
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    • 2004
  • The use of enantioselective hydrolysis for preparing chiral epichlorohydrins was investigated using recombinant Pichia pastoris with the enantioselective epoxide hydrolase of Rhodotorula glutinis. The rate of the recombinant epoxide hydrolase-catalyzed enantioselective hydrolysis of racemic epichlorohydrins was enhanced by the addition of 5%(v/v) Tween 20. Enantiopure (R)-epichlorohydrins with an enantiopurity of 100% ee and a yield of 26% were obtained within 5min from 50mM racemates.

UV Spectrometric Assay of Epoxide Hydrolase Activity of Microbial Cell Biocatalysts (자외선분광기를 이용한 미생물 세포 생촉매의 에폭사이드 가수분해효소 활성평가)

  • Kim, Hee Sook;Lee, Eun Yeol
    • Applied Chemistry for Engineering
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    • v.16 no.3
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    • pp.456-459
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    • 2005
  • UV spectrometric assay for measurement of epoxide hydrolase activity was tested for efficient screening of whole cell activity of epoxide hydrolase. Epoxide hydrolase activities were determined by measuring the amount of p-nitrostyrene diol (pNSD), which was the hydrolysis product of p-nitrostyrene oxide (pNSO). Enantioselective hydrolysis of racemic pNSO using epoxide hydrolase activity of Rhodosporidium toruloides was monitored by UV spectrometric assay, and the relevant $K_m$ and $V_m$ for R. toruloides were determined as $2.457nmol/min{\cdot}mg$ and 1.078 mM, respectively.

Studies on the Biologic Activities of the Constituents of Ailanthi Cortex Radicis(I) -Effects of Methanol Extract and its Chloroform Fraction on Epoxide Hydrolyzing System in Liver- (저근백피(樗根白皮) 성분(成分)의 생리생활(生理生活)에 관한 연구(硏究)(I) -메탄올 추출물과 클로로포름 분획이 Epoxide 분해계에 미치는 영향-)

  • Kim, Jong;Choi, Jong-Won;Kim, Hye-Kyung;Park, Soo-Wan;Lee, Chung-Kyu
    • Korean Journal of Pharmacognosy
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    • v.25 no.1
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    • pp.47-50
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    • 1994
  • For the biological survey, effects of Ailanthi Cortex Radicis, the root bark of Ailanthus altissima(Simaroubaceae) on epoxide hydrolyzing enzymes were checked. The methanolic extract and its chloroform fraction were shown to activate the liver metabolizing enzyme system including epoxide hydrolase system which was monitored by activities of transaminase, lactate dehydrogenase, alkaline phosphatase and epoxide hydrolase system in bromobenzene treated rats. But they showed no effect on glutathione S-transferase activity.

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