• Title/Summary/Keyword: fad

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Photactivated adenylyl cyclase, a novel blue-light receptor flavoprotein, mediates photoavoidance in the unicellular flagellate Euglena gracilis

  • Iseki, Mineo;Matsunaga, Shigeru;Murakami, Akio;Ohno, Kaoru;Shiga, Kiyoshi;Yoshida, Kazuichi;Sugai, Michizo;Takahashi, Tetsuo;Hori, Terumitsu;Watanabe, Masakatsu
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.98-101
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    • 2002
  • Euglena gracilis abruptly changes its swimming direction after a sudden increase or decrease in incident light intensity, that is, step-up or step-down photophobic responses, resulting in photoavoidance or photoaccumulation, respectively. To identify the photoreceptor molecules for these UV-A/blue-light type photobehaviors, we purified a flavoprotein from isolated putative photosencory organelles (PFBs) of Euglena. The purified flavoprotein, which noncovalently bound flavin adenine dinucleotide (FAD), seemed to be a heterotetramer of alpha- and beta-subunits. Predicted amino acid sequences of each of the subunits were similar to each other and contained two FAD-binding domains each followed by an adenylyl cyclase catalytic domain. The purified flavoprotein actually showed adenylyl cyclase activity, being drastically elevated by blue-light irradiation. Suppression of gene expression of the flavoprotein (Photoactivated Adenylyl Cyclase, PAC) by RNA interference (RNAi) caused loss of the step-up photophobic response, demonstrating that PAC actually mediates photoavoidance of Euglena.

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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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    • v.19 no.4
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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.

Carbon Monoxide Dehydrogenase in Cell Extracts of an Acinetobacter Isolate (Acinetobacter sp.1의 일산화탄소 산화효소의 특성)

  • 조진원;김영민
    • Korean Journal of Microbiology
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    • v.24 no.2
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    • pp.133-140
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    • 1986
  • Extracts of CO-autotrophically grown cells of Acinetobacter sp. 1 were shown to use thionin, methylene blue, or 2,6-dichlorophenol-indophenol, but not NAD, NADP, FAD, or FMN, as electron acceptors for the oxidation of CO under strictly anaerobic conditions. The CO dehydrogenase (CO-DH) in the thes bacterium was found to be an inducible enzyme. The enzyme activity was determined by an assay based on the CO-dependent reduction of thionin. Maximal reaction rates were found at pH 7.5 and $60^{\circ}C$, and the Arrhenius plot revealed an activation energy of 6.1 kcal/mol(25.5kJ/mol). THe $K_m$ m/ for CO was $154{\mu}M$. Known metalchelating agents tested had no effects on the CO-DH activity. No divalent cations tested affect the enzyme activity significantly escept $Cu^{2+}$ which suppressed the activity completely. The enzyme was inhibited by glucose and succinate. The same extracts catalyzed oxidation of hydrogen gas and formate with thionin as electron acceptor. The CO-DH of Acinetobacter sp. 1 was to have no immunological relationship with that of Pseudomonas carboxydohydrogena.

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Enhanced Production of Benzoylformate Reductase in Enterococcus faecalis under Oxidative Stress Established by Natural Electron Carriers

  • Baik, Sang-Ho;Cho, Pan-Ki;Kim, Mee-Hae;Yun, Sei-Eok
    • Journal of Microbiology and Biotechnology
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    • v.13 no.1
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    • pp.104-109
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    • 2003
  • Enhancement of the production of benzoylformate reductase (BFR) was attempted under oxidative stress established by natural electron carriers. -lipoic acid (LA), flavin adenine dinucleotide (FAD), and ubiquinone (UQ) did not inhibit growth of E. faecalis when their concentrations were as high as $10{\mu}M$, while $H_2O_2$ and methyl viologen ($MV^2+$) inhibited the bacterial growth. BFR activity in the bacterial extract had increased rapidly after 1 h of cultivation after the addition of $4{\mu}M$ of natural electron carriers, and the activity was maintained during further cultivation. BFR activity of the cells treated with the natural electron carriers was $40\%$ higher than that of the control. In the presence of $4{\mu}M\;H_2O_2\;and\;MV^2+$, BFR activity increased, reaching the highest activity at about 5 h cultivation, and then decreased with further cultivation. It seems that natural electron carriers not only stimulate the induction of BFR, but also stabilize the enzyme. BFR was hardly affected by LA, FAD, and UQ, while $H_2O_2\;and\;MV^2+$ inactivated the crude enzyme. The decrease of BFR activity in the presence of $H_2O_2\;and\;MV^2+$ might be ascribed to inactivation of the enzyme by the oxidants.

Evaluation of Korean distant water tuna fisheries in the Western and Central Pacific Ocean using ecosystem-based fishery risk assessment (중서부태평양해역 다랑어어업의 생태계기반 어업 위험도 평가)

  • KWON, Youjung;LIM, Jung-hyun;LEE, Mi Kyung;LEE, Sung Il
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.56 no.4
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    • pp.299-315
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    • 2020
  • Tuna fisheries were applied to an integrated ecosystem-based fishery risk assessment method using indexes of target species status, inhabited species in a target ecosystem, habitat quality and socio-economic benefit of affected fisheries. This study suggested more effective and efficient management measures to break away from traditional management methods, such as limitation of catch and fishing effort. The results presented that the objective risk index (ORIS) on sustainability of bigeye and yellowfin tunas by purse seine fishery was estimated high due to the high catch ratio of small fishes. The ORIs of biodiversity (ORIB) and habitat quality (ORIH) of purse seine fishery were also estimated at a high level from using fish-aggregating devices (FAD). However, due to skipjack tuna's high catches, the ORI of socio-economic benefit (ORIE) was estimated at a very low level. Due to the high bycatch rate, ORIB was high, and ORIS and ORIH were evaluated at a low level in longline fishery. Due to strengthern of fishing restrictions and increase of fishing costs, the ORIE was assessed to be very high. The ecosystem risk index (ERI) for two tuna fisheries was assessed low, but the overall FAD management by purse seine fishery is necessary at the ecosystem level.

Synthesis of Poly[3-hydroxybutyrate-co-3-hydroxyvalerate] by Recombinant Escherichia coli from Whey (재조합 대장균에 의한 유청으로부터 Poly[3-hydroxybutyrate-co-3-hydroxyvalerate] 합성)

  • 김범수;이상엽
    • KSBB Journal
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    • v.18 no.5
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    • pp.404-407
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    • 2003
  • Two recombinant Escherichia coli strains, GCSC6576 harboring a plasmid pSYL107 containing the Ralstonia eutropha polyhydroxyalkanoate (PHA) biosynthesis genes and a fadR atoC mutant LS5218 harboring a plasmid pJC4 containing the Alcaligenes latus PHA biosynthesis genes were compared for their ability to synthesize poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV) from whey. The 3HV fraction could be increased by acetic acid induction and oleic acid supplementation in flask cultures of recombinant E. coli GCSC6576. With the pH-stat fed-batch culture of recombinant E. coli LS5218, we obtained a cell concentration, a P(3HB-co-3HV) concentration, a P(3HB-co-3HV) content, and a 3HV fraction of 31.8 g/L, 10.6 g/L, 33.4%, and 6.26 mol%, respectively in 39 h.

Genetics and Breeding for Modified Fatty Acid Profile in Soybean Seed Oil

  • Lee, Jeong-Dong;Bilyeu, Kristin D.;Shannon, James Grover
    • Journal of Crop Science and Biotechnology
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    • v.10 no.4
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    • pp.201-210
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    • 2007
  • Soybean [Glycine max(L.) Merr.] oil is versatile and used in many products. Modifying the fatty acid profile would make soy oil more functional in food and other products. The ideal oil with the most end uses would have saturates(palmitic + stearic acids) reduced from 15 to < 7%, oleic acid increased from 23 to > 55%, and linolenic acid reduced from 8 to < 3%. Reduced palmitic acid(16:0) is conditioned by three or more recessive alleles at the Fap locus. QTLs for reduced palmitic acid have mapped to linkage groups(LGs) A1, A2, B2, H, J, and L. Genes at the Fad locus control oleic acid content(18:1). Six QTLs($R^2$=4-25%) for increased 18:1 in N00-3350(50 to 60% 18:1) explained four to 25% of the phenotypic variation. M23, a Japanese mutant line with 40 to 50% 18:1 is controlled by a single recessive gene, ol. A candidate gene for FAD2-1A can be used in marker-assisted breeding for high 18:1 from M23. Low linolenic acid(18:3) is desirable in soy oil to reduce hydrogenation and trans-fat accumulation. Three independent recessive genes affecting omega-3 fatty acid desaturase enzyme activity are responsible for the lower 18:3 content in soybeans. Linolenic acid can be reduced from 8 to about 4, 2, and 1% from copies of one, two, or three genes, respectively. Using a candidate gene approach perfect markers for three microsomal omega-3 desaturase genes have been characterized and can readily be used in for marker assisted selection in breeding for low 18:3.

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Fast and All-Purpose Area-Based Imagery Registration Using ConvNets (ConvNet을 활용한 영역기반 신속/범용 영상정합 기술)

  • Baek, Seung-Cheol
    • Journal of KIISE
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    • v.43 no.9
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    • pp.1034-1042
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    • 2016
  • Together with machine-learning frameworks, area-based imagery registration techniques can be easily applied to diverse types of image pairs without predefined features and feature descriptors. However, feature detectors are often used to quickly identify candidate image patch pairs, limiting the applicability of these registration techniques. In this paper, we propose a ConvNet (Convolutional Network) "Dart" that provides not only the matching metric between patches, but also information about their distance, which are helpful in reducing the search space of the corresponding patch pairs. In addition, we propose a ConvNet "Fad" to identify the patches that are difficult for Dart to improve the accuracy of registration. These two networks were successfully implemented using Deep Learning with the help of a number of training instances generated from a few registered image pairs, and were successfully applied to solve a simple image registration problem, suggesting that this line of research is promising.

Focal Adnexal Dysplasia in a Dog (개에서 Focal Adnexal Dysplasia 증례)

  • Park, Ho-Il;Hur, Won-Suk;Cho, Eun-Sang;Song, Sin-Hwa;Jeong, Seong-Mok;Cho, Sung-Whan;Son, Hwa-Young
    • Journal of Veterinary Clinics
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    • v.26 no.3
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    • pp.259-262
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    • 2009
  • Focal adnexal dysplasia(FAD) is a rare non-neoplastic lesion of adnexal appendages that occurs in dogs and has good prognosis. We report a case in which FAD diagnosis was favored by its histopathological features. A 8-year-old, castrated male American cocker spaniel dog presented with papillomatous masses on the distal phalanx of left forelimb. Histopathologically, the stroma was sharply demarcated from the adjacent dermis and subcutis. The adnexa was surrounded and interspersed with abundant, hyalinized collagen and the numerous sebaceous lobules distributed haphazardly around hair follicles, which is thickened, dilated and tortuous with abundant keratin. Epidermis was acanthotic. Proliferative lesions of the skin region are very common with similar gross features, thus the basic histopathological examination supported by additional diagnostic methods allow to establish the definitive diagnosis in most cases of cutaneous tumor or tumor-like lesions. And it is important that physicians and pathologists are aware of this unusual tumour-like nonneoplastic lesion.

Alzheimer's Disease-linked Swedish Amyloid Precursor Protein Mutation Induces Cell Death by Increasing Reactive Oxygen Species Generation

  • Kim Hye Sun;Lee Jun Ho;Kim Eun Mee;Lee Jean Pyo;Suh Yoo Hun
    • Environmental Mutagens and Carcinogens
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    • v.25 no.1
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    • pp.19-24
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    • 2005
  • The Swedish double mutation (KM670/671NL) of amyloid precursor protein (Swe-APP) is associated with early-onset familial Alzheimer's disease (FAD) and increases amyloid beta peptide production. Although APP/A/3 mediated neurotoxicity is observed both in vitro and in vivo, the relationship between mutant APP expression, A/3 production, and neuronal death observed in the brains of FAD patients remains to be elucidated. In this study, we investigated the mechanisms of Swe-APP-induced cell death in HEK293 and NGF-differentiated PC 12 cells. We found that the expression of Swe-APP induced cytochrome C relase, activation of caspase 3 in HEK 293 and NGF-differentiated PC 12 cells. We also show that the reactive oxygen species (ROS) was detected in Swe-APP expressing HEK 293 cells and NGF-differentiated PC 12 cells and that pretreatment with vitamine E attenuated the cellular death, cytochrome C release induced by Swe-APP expression, indicating the involvement of free radical in these processes. These results suggest one of possible apoptotic mechanisms of Swe-APP which could occur through cytochrome C release from mitochondria and this apoptosis inducing effects could be at least in part, due to ROS generation by Swe-APP expression.

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