• 제목/요약/키워드: flavin

검색결과 92건 처리시간 0.03초

Monoamine Oxidase의 억제 기구 (Mechanism of the Monoamine Oxidase Inhibition)

  • 강건일
    • 약학회지
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    • 제27권4호
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    • pp.321-329
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    • 1983
  • The review characterized active site(s) of MAO with respect to metal ions, hydrophobic and polar region, sulfhydryl group and flavin moiety. The mechanism of inhibition was dealt with three representative types of inhibitors; phenylcyclopropylamines, acetylenic amines, and hydrazines. Multiple forms of MAO was shortly described in relation to their selective inhibition. 84 reference were cited.

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Production of Bioactive 3'-Hydroxystilbene Compounds Using the Flavin-Dependent Monooxygenase Sam5

  • Heo, Kyung Taek;Lee, Byeongsan;Son, Sangkeun;Ahn, Jong Seog;Jang, Jae-Hyuk;Hong, Young-Soo
    • Journal of Microbiology and Biotechnology
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    • 제28권7호
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    • pp.1105-1111
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    • 2018
  • The flavin-dependent monooxygenase Sam5 was previously reported to be a bifunctional hydroxylase with coumarate 3-hydroxylase and resveratrol 3'-hydroxylase activities. In this article, we showed the Sam5 enzyme has 3'-hydroxylation activities for methylated resveratrols (pinostilbene and pterostilbene), hydroxylated resveratrol (oxyresveratrol), and glycosylated resveratrol (piceid) as substrates. However, piceid, a glycone-type stilbene used as a substrate for bioconversion experiments with the Sam5 enzyme expressed in Escherichia coli, did not convert to the hydroxylated compound astringin, but it was converted by in vitro enzyme reactions. Finally, we report a novel catalytic activity of Sam5 monooxygenase for the synthesis of piceatannol derivatives, 3'-hydroxylated stilbene compounds. Development of this bioproduction method for the hydroxylation of stilbenes is challenging because of the difficulty in expressing P450-type hydroxylase in E. coli and regiospecific chemical synthesis.

Liquid Chromatography-Tandem Mass Spectrometry Analysis of Riboflavin in Beagle Dog Plasma for Pharmacokinetic Studies

  • Jeong, Hyeon Myeong;Shin, Beom Soo;Shin, Soyoung
    • Mass Spectrometry Letters
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    • 제11권1호
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    • pp.10-14
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    • 2020
  • Riboflavin is a water-soluble vitamin, which serves as a precursor to flavin mononucleotide and flavin adenine dinucleotide. This study aimed to develop a simple and rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis for the quantification of riboflavin in the Beagle dog plasma. This method utilized simple protein precipitation with acetonitrile and 13C4, 15N2-riboflavin was used as an internal standard (IS). For chromatographic separation, a hydrophilic interaction liquid chromatography (HILIC) column was used with gradient elution. The mobile phase consisted of 0.1% (v/v) aqueous formic acid with 10 mM ammonium formate and acetonitrile with 0.1% (v/v) formic acid. Since riboflavin is an endogenous compound, 4% bovine serum albumin in phosphate buffered saline was used as a surrogate matrix to prepare the calibration curve. The quantification limit for riboflavin in the Beagle dog plasma was 5 ng/mL. The method was fully validated for its specificity, sensitivity, accuracy and precision, recovery, and stability according to the US FDA guidance. The developed LC-MS/MS method may be useful for the in vivo pharmacokinetic studies of riboflavin.

Methylophaga aminosulfidovorans SKI bfmo 오페론의 클로닝 및 구조 분석 (Cloning and Structural Analysis of bfmo Operon in Methylophaga aminosulfidovorans SK1)

  • 임현숙;구재환;김리현;김시욱;조은희
    • 미생물학회지
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    • 제41권1호
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    • pp.1-7
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    • 2005
  • Methylophaga aminosulfidovorans SK1 (KCTC 10323 BP)은 단일 탄소원, 질소원 그리고 에너지원으로 난분해성 화합물인 트리메틸아민을 이용할 수 있다. M. aminosulfidovorans SK1는 진핵세포의 flavin-containing monooxygenase와 유사한 유전자(bFMO)를 지니고 있으며 대장균에서 발현된 재조합 단백질은 강력한 트리메틸아민 산화활성을 보인다. 본 연구에서는 bEMO의 기능과 조절 메커니즘을 연구하기 위하여 bfmo의 상단부 및 하단부 유전자의 염기서열을 결정하였다. bfmo 상단부의 세 개의 열린해독틀은 잘 보존된 nitrate/nitrite response regulators와 methyl accepting protein 유사단백질을 암호화하였다. 하단부의 두 개의 작은 열린해독틀은 기능은 알려져 있지 않지만 진정세균계에서 잘 보존된 단백질의 일종으로 나타났다. 역전사효소 중합효소증폭반응을 통하여 여섯 개의 유전자는 세 개의 독립된 오페론으로 구성되어 있음을 확인하였다. bfmo의 상단부에 위치하는 세 개의 조절유전자는 두 개의 프로모터에서 전사되었다. 그리고 이와 독립적으로 bfmo와 두 개의 하단부 유전자가 하나의 전사단위를 이루고 있다.

Substrate Specificity of Human Flavin-containing monooxygenase 1 for Thiocarbamides

  • Jung, Ki-Hwa;D. M. Ziegler;Kim, Young-Mi
    • 한국환경독성학회:학술대회논문집
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    • 한국환경독성학회 2001년도 춘계심포지움 및 학술발표회
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    • pp.124-124
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    • 2001
  • Microsomes isolated from Spodoptera frugiperda (Sf)9 cells infected wi th human FM01 recombinant baculovirus catalyzed the NADPH- and 02-dependent oxidation of methimazole, thiourea, and phenylthiourea. However there was no detectable activity with 1,3-diphenylthiourea or larger thiocarbamides. Microsomes from control Sf9 cells were devoid of methimazole or thiourea S-oxygenase activity. (omitted)

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Production, Purification, and Characterization of Soluble NADH-Flavin Oxidoreductase(StyB) from Pseudomonas putida SN1

  • Yeo, Yun-Ji;Shin, Seung-Hee;Lee, Sun-Gu;Park, Sung-Hoon;Jeong, Yong-Joo
    • Journal of Microbiology and Biotechnology
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    • 제19권4호
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    • pp.362-367
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    • 2009
  • In recombinant strains, many proteins and enzymes are expressed as inactive and insoluble inclusion bodies. For soluble expression of an active form of StyB, an NADH-flavin oxidoreductase, several recombinant Escherichia coli strains were developed and tested. Among them, strain BL21(DE3)pLysS effectively produced an active and soluble form of StyB as about 9% of the total protein content, when cultivated at $20^{\circ}C$ with 0.5 mM IPTG. The solubly expressed StyB has the highest oxidoreductase activity at pH 6.5-7.5 and $37^{\circ}C$. Substrate dependence profiles of the StyB-catalyzed reaction showed that the maximum specific activity($V_m$) and half saturation constant($K_m$) were $1,867{\pm}148\;U/mg$ protein and $51.6{\pm}11{\mu}M$ for NADH, and $1,274{\pm}34\;U/mg$ protein and $8.2{\pm}1.2{\mu}M$ for FAD, respectively. This indicates that solubly produced StyB has 6- to 9-fold higher oxidoreductase activities than the in vitro refolded StyB from inclusion bodies.