• Title/Summary/Keyword: electron transport chain

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Effects of Local Anesthetics on Electron Transport and Generation of Superoxide Radicals in Mitochondria (국소마취제가 Mitochondria에서의 전자이동 및 Superoxide Radicals의 생성에 미치는 영향)

  • Lee, Chung-Soo;Shin, Yong-Kyoo;Lee, Kwang-Soo
    • The Korean Journal of Pharmacology
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    • v.23 no.2
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    • pp.113-121
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    • 1987
  • Local anesthetics were investigated for their effects on mitochondrial electron transport system, production of superoxide radical from submitochondrial particles and malondialdehyde production through lipid per oxidation. Local anesthetics had various effects on activities of enzymes in electron transport chain. The activities of NADH dehydrogenase, NADH oxidase and NADH-ubiquinone oxidoreductase were effectively inhibited by lidocaine, procaine and dibucaine but slightly influenced by cocaine. The activities of succinate dehydrogenase, succinate-cytochrome c oxidoreductase and succinate-ubiquinone oxidoreductase were inhibited by lidocaine and dibucaine, but the succinate oxidase activity was stimulated by local anesthetics. Both dihydroubiquinone-cytochrome c oxidoreductase and cytochrome c oxidase activities were inhibited by local anesthetics. In these reactions, the response of Complex I segment to local anesthetics was greater than other Complex segments. Local anesthetics inhibited both the superoxide production from submitochondrial particles supplemented with succinate or NADH and the enhanced production of superoxide radicals by antimycin. The malondialdehyde production by oxygen free radicals was inhibited by local anesthetics. These results suggest that the inhibition of superoxide and malondialdehyde production caused by local anesthetics may be brought by suppression of the electron transport in mitochondria at sites in or near complex I segment.

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$TiO_2$ Nanocubes for Rapid Electron Transfer in Dye-Sensitized Solar Cell

  • Yang, Hye-Yeong;Bang, So-Yeon;Lee, Do-Gwon;Go, Min-Jae;Kim, Gyeong-Gon
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.317-317
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    • 2010
  • This paper reports syntheses of $TiO_2$ nanocubes and theirs application to DSSC. We synthesized $TiO_2$ nanocubes via solvothermal method using titanium isopropoxide (TTIP) and tetramethylammoiumhydroxide (TMAH). By adding longer alkyl chain ammonium hydroxide that slowed down the growth rate of the crystal, $TiO_2$ nanocubes were obtained with average particle size in the range of 40 nm to 70 nm. By TEM investigation, each particle was found to be single crystal of anatase having six-faces of (001) and {100} crystallographic planes truncated by {101} series of planes, which are clearly distinguishable from spherical nanoparticles. Among various application, utilizing nanocubes as photo-electrode in dye-sensitized solar cell, we investigated photo-electron conversion performances in comparison with spherical shaped $TiO_2$ nanoparticles by I-V characteristics and IPCE measurements, etc.. Photocurrent-transient analysis revealed that $TiO_2$ nanocubes have a higher transient electron transfer rate by more than 10 times compared with spherical particles of similar size. Fast electron transport along the cube edges having small curvature was suggested as a plausible origin of high diffusion coefficient of electron in nanocube $TiO_2$.

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Detection of Mitochondrial Reactive Oxygen Species in Living Rat Trigeminal Caudal Neurons

  • Lee, Hae In;Chun, Sang Woo
    • International Journal of Oral Biology
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    • v.40 no.2
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    • pp.103-109
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    • 2015
  • Growing evidence suggests that mitochondrial reactive oxygen species (ROS) are involved in various pain states. This study was performed to investigate whether ROS-induced changes in neuronal excitability in trigeminal subnucleus caudalis are related to ROS generation in mitochondria. Confocal scanning laser microscopy was used to measure ROS-induced fluorescence intensity in live rat trigeminal caudalis slices. The ROS level increased during the perfusion of malate, a mitochondrial substrate, after loading of 2',7'-dichlorofluorescin diacetate ($H_2DCF-DA$), an indicator of the intracellular ROS; the ROS level recovered to the control condition after washout. When pre-treated with phenyl N-tert-butylnitrone (PBN) and 4-hydroxy-2,2,6,6-tetramethylpiperidene-1-oxyl (TEMPOL), malate-induced increase of ROS level was suppressed. To identify the direct relation between elevated ROS levels and mitochondria, we applied the malate after double-loading of $H_2DCF-DA$ and chloromethyl-X-rosamine (CMXRos; MitoTracker Red), which is a mitochondria-specific fluorescent probe. As a result, increase of both intracellular ROS and mitochondrial ROS were observed simultaneously. This study demonstrated that elevated ROS in trigeminal subnucleus caudalis neuron can be induced through mitochondrial-ROS pathway, primarily by the leakage of ROS from the mitochondrial electron transport chain.

A study on the application and counter measures of IC tag in international marine container transport (국제해상컨테이너운송에서 보안강화를 위한 전자태그(IC tag)의 적용과 대응방안)

  • Han, Sang-Hyun;Choi, Jun-Ho
    • International Commerce and Information Review
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    • v.12 no.2
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    • pp.133-158
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    • 2010
  • Since 11 September 2001, the awareness of terrorists' actions has clearly risen. The potential threat of terrorists using containers poses a large risk to our economies and to our societies. In order to protect cargo from damage and terrorist threats, business and government turn to RFID and IC tags, and tradition container is replaced by IC smart container. In this study, presented application of IC tag and future tasks to Container transport by sea in viewpoint of security strengthening. First, realization and international SCM realization structural order that cover container supply chain whole of international standardization and association between industry are certainly needed. Second, it may have to try in technical development for IC tag Ratio that can read elevation moment develop suitable IC tag or reader in International Standard. Third, Need to establish concrete use policy as soon as possible in national dimension at the same time effort for international standard normalization of frequency. Finally, it shows to uses jointly with electron sealing and must solve problem about usable plan and information leak.

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Characteristics of Organic Light-Emitting Diodes using PECCP Langmuir-Blodgett(LB) Film as an Emissive Layer (PECCP LB 박막을 발광층으로 사용한 유기 발광 다이오드의 특성)

  • Lee, Ho-Sik;Lee, Won-Jae;Park, Jong-Wook;Kim, Tae-Wan;Dou--Yol Kang
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.11a
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    • pp.111-114
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    • 1999
  • Electroluminescence(EL) devices based on organic thin films have been attracted lots of interests in large-area light-emitting display. In this stuffy, an emissive layer was fabricated using Langmuir-Blodgett(LB) technique in organic light-emitting (OLEDs). This emissive organic material was synthesized and named PECCP[poly(3.6-N-2-ethylhexyl carbazolyl cyanoterephthalidene)] which has a strong electron donor group and an electron acceptor group in main chain repeated unit. This material has good solubility in common organic solvents such as chloroform. THF, etc, and has a good stability in air. The Langmuir-Blodgett(LB) technique has the advantage of precise control of the thickness down to the molecular scale, In particular, by varying the film thickness it is possible to investigate the metal/polymer interface. Optimum conditions for the LB film deposition are usually determined by investigating a relationship between a surface pressure $\pi$ and an effective are A occupied by one molecule on the subphase. The LB films were deposited on an indium-tin-oxide(ITO) glass at a surface pressure of 10 mN/m and dipping speed of 12 mm/min after spreading PECCP solution on distilled water surphase at room temperature, Cell structure was ITO/PECCP LB film/Alq$_3$/Al. We considered PECCP as a hole -transport layer inserted between the emissive layer and ITO. We also used Alq$_3$ as an emissive layer and an electron transport layer. We measured current-voltage(I-V) characteristics, UV/visible absorption, PL spectrum and EL spectrum of the OLEDs.

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Biological activity of quinoline derivatives as inhibitors of NADH-ubiquinone oxidoreductase in the respiratory chain (NADH-ubiquinone oxidoreductase 저해제인 quinoline 유도체들의 생리활성)

  • Chung, Kun-Hoe;Cho, Kwang-Yun;Takahashi, Nobutaka;Yoshida, Shigeo
    • Applied Biological Chemistry
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    • v.34 no.1
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    • pp.43-48
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    • 1991
  • New quinoline compounds were designed, synthesized, and examined with submitochondria. Most compounds showed high activity against NADH-ubiquinone oxidoreductase. Inhibition activity was mainly affected by the length of the lipophilic part, regardless of bulkiness or location of a phenyl group in the side chain. The $\beta-methyl$ group was demons)rated to be the optimal functionality on the nuclei of the quinoline derivatives so 4hat either deletion or insertion of a methylene on the group eliminated its activity.

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Coenzyme Q10: a progress towards the treatment of neurodegenerative disease

  • Kumar, Peeyush;Kumar, Pramod;Ram, Alpana;Kuma, Mithilesh;Kumar, Rajeev
    • Advances in Traditional Medicine
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    • v.10 no.4
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    • pp.239-253
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    • 2010
  • Coenzyme $Q_{10}$ ($CoQ_{10}$, or ubiquinone) is an electron carrier of the mitochondrial respiratory chain (electron transport chain) with antioxidant properties. In view of the involvement of $CoQ_{10}$ in oxidative phosphorylation and cellular antioxidant protection a deficiency in this quinone would be expected to contribute to disease pathophysiology by causing a failure in energy metabolism and antioxidant status. Indeed, a deficit in $CoQ_{10}$ status has been determined in a number of neuromuscular and neurodegenerative disorders. Primary disorders of $CoQ_{10}$ biosynthesis are potentially treatable conditions and therefore a high degree of clinical awareness about this condition is essential. A secondary loss of $CoQ_{10}$ status following HMG-CoA reductase inhibitor (statins) treatment has been implicated in the pathophysiology of the myotoxicity associated with this pharmacotherapy. $CoQ_{10}$ and its analogue, idebenone, have been widely used in the treatment of neurodegenerative and neuromuscular disorders. These compounds could potentially play a role in the treatment of mitochondrial disorders, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, Friedreich's ataxia, and other conditions which have been linked to mitochondrial dysfunction. This article reviews the physiological roles of $CoQ_{10}$, as well as the rationale and the role in clinical practice of $CoQ_{10}$ supplementation in different neurological diseases, from primary $CoQ_{10}$ deficiency to neurodegenerative disorders. These will help in future for treatment of patients suffering from neurodegenerative disease.

Expression of Extracellular Superoxide Dismutase Protein in Diabetes

  • Kim, Chul Han
    • Archives of Plastic Surgery
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    • v.40 no.5
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    • pp.517-521
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    • 2013
  • Background Diabetes is characterized by chronic hyperglycemia, which can increase reactive oxygen species (ROS) production by the mitochondrial electron transport chain. The formation of ROS induces oxidative stress and activates oxidative damage-inducing genes in cells. No research has been published on oxidative damage-related extracellular superoxide dismutase (EC-SOD) protein levels in human diabetic skin. We investigated the expression of EC-SOD in diabetic skin compared with normal skin tissue in vivo. Methods The expression of EC-SOD protein was evaluated by western blotting in 6 diabetic skin tissue samples and 6 normal skin samples. Immunohistochemical staining was also carried out to confirm the EC-SOD expression level in the 6 diabetic skin tissue samples. Results The western blotting showed significantly lower EC-SOD protein expression in the diabetic skin tissue than in the normal tissue. Immunohistochemical examination of EC-SOD protein expression supported the western blotting analysis. Conclusions Diabetic skin tissues express a relatively small amount of EC-SOD protein and may not be protected against oxidative stress. We believe that EC-SOD is related to the altered metabolic state in diabetic skin, which elevates ROS production.

$Na^+$ Requirement of NADH dehydrogenase from an Extreme halophile, Halobacterium sp. EH10 Isolated from a Saltern in Korea (Halobacterium sp. EH10 NADH dehydrogenase의 $Na^+$ 요구성)

  • Bae, Moo;Lee, Jeong-Im
    • Microbiology and Biotechnology Letters
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    • v.19 no.2
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    • pp.153-157
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    • 1991
  • Intracellular enzymes of an extreme halophilic bacterium, Halobacterium sp. HE10, isolated from a saltern in Korea was investigated. The membrane-bound enzyme, NADH dehydrogenase, involved in electron transport system was stimulated by the addition of 2.0 M NaCl. The respiratory enzyme activities such as NADH oxidase and NADH dehydrogenase was decreased on removal of $Na^+$ ion and restored when replaced with cations like $K^+$, $Li^+$and $NH_{4}^{+}$ ions. Furthermore, their activities were affected by the anions such like carbonate, acetate, sulfate, chloride and nitrate at the presence of $Na^+$ion. Lactate dehydrogenase activity was highest at the asturated solution of NaCl and isocitrate dehydrogenase activity was a maximum level at 1.0 M NaCl. These results suggested that the enzyme activites of the respiratory chain in Halobacterium sp. EH10 was stimulated by the presence of $Na^+$ ion.

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Iron Starvation-Induced Proteomic Changes in Anabaena (Nostoc) sp. PCC 7120: Exploring Survival Strategy

  • Narayan, Om Prakash;Kumari, Nidhi;Rai, Lal Chand
    • Journal of Microbiology and Biotechnology
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    • v.21 no.2
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    • pp.136-146
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    • 2011
  • This study provides first-hand proteomic data on the survival strategy of Anabaena sp. PCC 7120 when subjected to long-term iron-starvation conditions. 2D-gel electrophoresis followed by MALDI-TOF/MS analysis of iron-deficient Anabaena revealed significant and reproducible alterations in ten proteins, of which six are associated with photosynthesis and respiration, three with the antioxidative defense system, and the last, hypothetical protein all1861, conceivably connected with iron homeostasis. Iron-starved Anabaena registered a reduction in growth, photosynthetic pigments, PSI, PSII, whole-chain electron transport, carbon and nitrogen fixation, and ATP and NADPH content. The kinetics of hypothetical protein all1861 expression, with no change in expression until day 3, maximum expression on the $7^{th}$ day, and a decline in expression from the $15^{th}$ day onward, coupled with in silico analysis, suggested its role in iron sequestration and homeostasis. Interestingly, the up-regulated FBP-aldolase, Mn/Fe-SOD, and all1861 all appear to assist the survival of Anabeana subjected to iron-starvation conditions. Furthermore, the $N_2$-fixation capabilities of the iron-starved Anabaena encourage us to recommend its application as a biofertilizer, particularly in iron-limited paddy soils.