• 제목/요약/키워드: Dehydrogenase activity

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대장균에서 Selenocysteine을 가지고 있는 Formate Dehydrogenase H의 최적화 생산 (Optimized Production of Selenocysteine Containing Formate Dehydrogenase H in Escherichia coli)

  • 사영승;김용환
    • KSBB Journal
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    • 제26권3호
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    • pp.189-192
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    • 2011
  • Much interest has been recently focused on the production of large quantities of hydrogen, due to its potential importance in our economy and needs in the petroleum and chemical industries. Formate dehydrogenase H (FDH-H) from Escherichia coli containing selenocysteine that oxidizes formate to carbon dioxide with the release of hydrogen is a component of the anaerobic formate hydrogen-lyase complex of E. coli. To make full use of FDH-H, we need effective expression condition. In this approach, we investigated the effect of pH on FDH-H stability and observed the effect of selenite and formate concentration on the activity of FDH-H. Additionally, coexpression of selenocysteine insertion genes were tried to improve the expression of FDH-H. The highest level of FDH-H expression was achieved by coexpression of selenocysteine insertion genes (pSUABC) as well as by the addition of $10\;{\mu}M$ selenite and 10 mM formate. At this optimized condition, a 2.6 fold elevation of expression of FDH-H was achieved.

대장균으로 부터 생산된 L-lactate Dehydrogenase의 정제 및 특성 (Purification and Properties of Thermostable L-Lactate Dehydrogenase Produced by Escherichia Coli)

  • Song, Jae-Young;Kim, Kyoug-Sook
    • 한국식품영양과학회지
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    • 제23권6호
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    • pp.964-972
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    • 1994
  • The 4.3-kb gene coding for L-lactate dehydrogenase of Bacillus stearothermophilus has been subcloned and expressed in E. coli cells. The enzyme was purified 200-fold with 25% yield by heat treatment , DEAE-Sephadex, and NAD++ -Sepharose CL-4B affinity chromatography followed by gel filtration through Sephadex G-200 . The molecular weight of the purfied enzyme was estimated to be about 35, 000 and 140, 000 on SDS-polyacrylamide gel electrophoresis and gel filtration, respectively. indicating that the enzyme is composed of four identical subunits. THe enzyme for pyruvate reduction and lactate oxdiation was stable at 60 and 75$^{\circ}C$ for 30 min, and the optimal temperatures for both reactions were 60 and 7$0^{\circ}C$, respectively. The enzyme had an optimal pH at 5.5 and 8.5 in pyruvate reduction and lactate oxidation, respectively. The pH stability of enzyme of pyruvate reduction was table between pH 5 and 7. more than 90% of enzyme activity was lost at 1mM FeSO4 and p-chloromercuribonzoate. The maximal activation of the enzyme was obtained with 0.8mM fructose 1, 6-bisphosphate.

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Stereoselective Bioreduction of Ethyl 3-Oxo-3-(2-Thienyl) Propanoate Using the Short-Chain Dehydrogenase/Reductase ChKRED12

  • Ren, Zhi-Qiang;Liu, Yan;Pei, Xiao-Qiong;Wu, Zhong-Liu
    • Journal of Microbiology and Biotechnology
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    • 제29권11호
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    • pp.1769-1776
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    • 2019
  • Ethyl (S)-3-hydroxy-3-(2-thienyl) propanoate ((S)-HEES) acts as a key chiral intermediate for the blockbuster antidepressant drug duloxetine, which can be achieved via the stereoselective bioreduction of ethyl 3-oxo-3-(2-thienyl) propanoate (KEES) that contains a 3-oxoacyl structure. The sequences of the short-chain dehydrogenase/reductases from Chryseobacterium sp. CA49 were analyzed, and the putative 3-oxoacyl-acyl-carrier-protein reductase, ChKRED12, was able to stereoselectively catalyze the NADPH-dependent reduction to produce (S)-HEES. The reductase activity of ChKRED12 towards other substrates with 3-oxoacyl structure were confirmed with excellent stereoselectivity (>99% enantiomeric excess) in most cases. When coupled with a cofactor recycling system using glucose dehydrogenase, the ChKRED12 was able to catalyze the complete conversion of 100 g/l KEES within 12 h, yielding the enantiopure product with >99% ee, showing a remarkable potential to produce (S)-HEES.

방사선 유도 돌연변이체 블랙베리 발효음료의 알코올 대사 및 숙취 억제 효과 (Effect of Fermented Blackberry Drinks Formed from Radiation-induced Mutant on Alcohol Metabolism and Hangover in Rats)

  • 조병옥;소양강;이창욱;조정근;우현심;진창현;정일윤
    • 방사선산업학회지
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    • 제7권1호
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    • pp.75-80
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    • 2013
  • This study was designed to elucidate the effect of fermented blackberry drinks (BD) on alcohol metabolism and hangover in alcohol-treated rats. We showed that the administration of BD increased the activity of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) in alcohol-treated rats. Moreover, the administration of BD reduced the serum alcohol and acetaldehyde concentrations in alcohol-treated rats. Furthermore, the administration of BD attenuated the levels of serum aspartate aminotransferase and alanine aminotransferase in alcohol-treated rats. Taken together, these results suggest that BD plays an important role in alcohol metabolism and liver function by reducing blood alcohol and acetaldehyde through the activation of ADH and ALDH in alcohol-treated rats and could be used as a functional anti-hangover drinks.

Carbonic Maceration처리에 의한 Campbell Early 발효액의 감산 효과: 사과산 대사 관련 효소활성의 영향 (Deacidification Effect of Campbell Early Must via Carbonic Maceration : Effect of Enzyme Activity Associated with Malic-Acid Metabolism)

  • 장은하;정석태;정성민;노정호;박교선;박서준;최종욱
    • 한국식품저장유통학회지
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    • 제18권5호
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    • pp.795-802
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    • 2011
  • Carbonic maceration처리 포도주에 있어 유기산 특히 사과산 함량을 감소시키는 주요 원인을 찾고자 포도를 2주 동안 온도별 carbonic maceration 처리하며 시기별로 산함량 및 사과산대사 관련 효소활성을 측정하였다. 온도별 carbonic maceration 처리 포도의 pH는 CM-$25^{\circ}C$와 CM-$35^{\circ}C$에서 처리 시간이 경과할수록 가장 높았으며, 총산은 초기에는 CM-$35^{\circ}C$에서 가장 낮은 함량을 나타내었지만 처리 6일 이후 서서히 증가하였고, CM-$25^{\circ}C$는 처리 완료일 까지 꾸준히 감소하는 것으로 나타났다. CM-$45^{\circ}C$는 초기와 비슷한 함량을 나타내어 다른 처리보다 높은 총산 함량을 나타내었다. 유기산 함량에 있어 사과산 함량은 CM-$35^{\circ}C$에서 가장 많이 감소하였고, 젖산 함량은 CM-$35^{\circ}C$에서 가장 높게 나타났다. 사과산 대사과련 효소활성을 살펴본 결과, malic enzyme과 malic dehydrogenase는 CM-$25^{\circ}C$와 CM-$35^{\circ}C$에서 가장 높은 효소활성을 나타내었지만 CM-$45^{\circ}C$에서는 초기부터 효소활성이 나타나지 않았다. oxalacetate decarboxylase 활성도 malic dehydrogenase 활성과 비슷한 경향을 나타내었다. pyruvate decarboxylase 활성은 다른 효소활성에 비해 활성이 낮았지만, CM-$45^{\circ}C$에서도 활성을 나타내었다. 반면 L-lactic dehydrogenase 활성은 어떤 처리구에서도 나타나지 않았다. 이와 같은 결과로부터 온도와 효소활성과의 관계에 있어 온도가 $40^{\circ}C$ 이상에서는 사과산 대사관련 효소가 활성을 나타내지 않는 것을 알 수 있었고, carbonic maceration 처리에서 사과산 감소가 효소의 작용에 크게 영향 받는 것을 확인할 수 있었지만, 젖산 생성에 대해서는 효소작용 외에 사과산 대사 미생물과 같은 다른 요인들에 대해 좀 더 깊이 있는 연구가 필요하다.

Molecular Cloning and Expression of Human Dihydrolipoamide Dehydrogenase-Binding Protein in Excherichia coli

  • Lee, Jeong-Min;Ryou, Chong-Suk;Kwon, Moo-Sik
    • Journal of Microbiology and Biotechnology
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    • 제11권4호
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    • pp.592-597
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    • 2001
  • The pyruvate dehydrogenase complex (PDC) catalyzes the oxidative decarboxylation of pyruvate with the formation of $CO_2$, acetyl-CoA, NADH, and H+. This complex contains multiple copies of three catalytic components including pyruvate dehydrogenase(E1), dihydrolipoamide acetyltransferase(E2), and dihydrolipoamide dehydrogenase (E3). Two regulatory components (E1-kinase and phospho-E1 phosphatase) and functionally less-understood protein (protein X, E3BP) are also involved in the formation of the complex. In this study, cloning and characterization of a gene for human E3BP have been carried out. A cDNA encoding the human E3BP was isolated by database search and cDNA library screening. The primary structure of E3BP has some similar characteristics with that of E2 in the lipoyl domain and the carboxyl-terminal domain, based on the nucleotide sequence and the deduced amino acid sequence. However, the conserved amino acid moiety including the histidine residue for acetyltransferase activity in E2 is not conserved in the case of human E3BP. The human E3BP was expressed and purified in E. coli. The molecular weight of the protein, excluding the mitochondrial target sequence, was about 50 kDa as determined by SDS-PAGE. Cloning of human E3BP and expression of the recombinant E3BP will facilitate the understanding of the role(s) of E3BP in mammalian PDC.

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Cloning and Characterization of Cyclohexanol Dehydrogenase Gene from Rhodococcus sp. TK6

  • CHOI JUN-HO;KIM TAE-KANG;KIM YOUNG-MOG;KIM WON-CHAN;JOO GIL-JAE;LEE KYEONG-YEOLL;RHEE IN-KOO
    • Journal of Microbiology and Biotechnology
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    • 제15권6호
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    • pp.1189-1196
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    • 2005
  • The cyclohexanol dehydrogenase (ChnA), produced by Rhodococcus sp. TK6, which is capable of growth on cyclohexanol as the sole carbon source, has been previously purified and characterized. However, the current study cloned the complete gene (chnA) for ChnA and its flanking regions using a combination of a polymerase chain reaction (PCR) based on the N-terminal amino acid sequence of the purified ChnA and plaque hybridization from a phage library of Rhodococcus sp. TK6. A sequence analysis of the 5,965-bp DNA fragment revealed five potential open reading frames (ORFs) designated as partial pte (phosphotriesterase), acs (acyl-CoA synthetase), scd (short chain dehydrogenase), stp (sugar transporter), and chnA (cyclohexanol dehydrogenase), respectively. The deduced amino acid sequence of the chnA gene exhibited a similarity of up to $53\%$ with members of the short-chain dehydrogenase/reductase (SDR) family. The chnA gene was expressed using the pET21 a(+) system in Escherichia coli. The activity of the expressed ChnA was then confirmed (13.6 U/mg of protein) and its properties investigated.