• Title/Summary/Keyword: Respiratory chain complex

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Enzymatic Properties of the Membrane-bound NADH Oxidase System in the Aerobic Respiratory Chain of Bacillus cereus

  • Kim, Man-Suk;Kim, Young-Jae
    • BMB Reports
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    • v.37 no.6
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    • pp.753-756
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    • 2004
  • Membranes prepared from Bacillus cereus KCTC 3674, grown aerobically on a complex medium, oxidized NADH exclusively, whereas deamino-NADH was little oxidized. The respiratory chain-linked NADH oxidase exhibited an apparent $K_m$ value of approximately $65\;{\mu}m$ for NADH. The maximum activity of the NADH oxidase was obtained at about pH 8.5 in the presence of 0.1 M KCl (or NaCl). Respiratory chain inhibitor 2-heptyl-4-hydroxyquinoline-N-oxide (HQNO) inhibited the activity of the NADH oxidase by about 90% at a concentration of $40\;{\mu}m$. Interestingly, rotenone and capsaicin inhibited the activity of the NADH oxidase by about 60% at a concentration of $40\;{\mu}m$ and the activity was also highly sensitive to $Ag^+$.

Structural Studies of Respirasome by Cryo-Electron Microscopy

  • Jeon, Tae Jin;Kim, Ho Min;Ryu, Seong Eon
    • Applied Microscopy
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    • v.48 no.4
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    • pp.81-86
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    • 2018
  • The respiratory chain complex forms a supercomplex (SC) in the inner mitochondrial membrane. This complex facilitates the process of electron transfer to produce the proton gradient used to synthesize ATP. Understanding the precise structure of the SC is considered an important challenge. However, it has not yet been reported. The development of a Cryo-electron microscopy (EM) technique provides an effective way to obtain high-resolution micrographs to determine the high-resolution three-dimensional structure of biomolecules. In this brief review, the currently reported Cryo-EM structures of the mammalian respirasome have been described in order to establish a direction for further research in the respiratory system.

The Effects of Acupuncture at LR3 Acupoint on Mitochondrial Complex IV Oxidase activity in Liver (태충 침자가 간 미토콘드리아 내 Complex IV에 미치는 영향)

  • Choi, Donghee;Lee, Yumi;Kim, Mirae;Park, Jeonghye;Kim, Hyeran;Na, Changsu;Youn, Daehwan
    • Korean Journal of Acupuncture
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    • v.36 no.4
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    • pp.200-209
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    • 2019
  • Objectives : The liver is rich in mitochondria and it plays a key role in whole-body energy homeostasis. Mitochondria is double membrane-bound organelle that supplies energy for intracellular metabolism including Krebs cycle and beta-oxidation. Acupuncture is known to stimulate and regulate the flow of energy. To explore the effect of acupuncture on the mitochondrial respiratory chain activity in the rats' livers, the activity of mitochondrial respiratory chain complexes I to IV was observed. Methods : The rats were divided into 4 groups; Normal 1 (no acupuncture treatment and anesthesia for 5 min), Normal 2 (no acupuncture treatment and anesthesia for 10 min), MA1 (acupuncture treatment at bilateral LR3 under anesthesia for 5 min), and MA2 (acupuncture treatment at bilateral LR3 under anesthesia for 10 min). All rats were sacrificed and the livers were examined for respiratory chain change. Results : There was no difference in ubiquinon oxidoreductase, succinate dehydrogenase, and ubiquinol cytochrome C oxidoreductase after acupuncture at LR3. Acupuncture at LR3 for 10 min increased the activity of cytochrome C oxidase compared with no acupuncture groups. Conclusions : Acupuncture at LR3 mediated mitochondrial respiratory chain activity via the cytochrome C oxidase signaling pathway in the livers of rats.

A Case of Mitochondrial Respiratory Chain Defect with Progressive Bilateral Cararacts (진행성 양측 백내장이 동반된 미토콘드리아 질환 1례)

  • Lee, Soonie;Lee, Young-Mock
    • Journal of The Korean Society of Inherited Metabolic disease
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    • v.18 no.3
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    • pp.95-98
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    • 2018
  • A striking feature of mitochondrial disorders is the vast heterogeneity in their clinical symptoms that ranges from a single organ to severe multisystem involvement. Though a variety of ocular symptoms such as ptosis, pigmentary retinal degeneration, external ophthalmoplegia, and optic nerve atrophy can occur in association with mitochondrial cytopathies, progressive bilateral cataracts are rare among their ocular findings. A 5-year-old girl with no previous medical history came to our hospital presenting symptoms of seizure. She started showing progressive developmental regression, increased seizure frequency, hypotonia, general weakness, dysphagia and decreased vision. Lactic acidosis was noted in metabolic screening test and we confirmed mitochondrial respiratory chain complex I defect in spectrophotometric enzyme assay using the muscle tissue. Progressive bilateral cataracts then developed and were fully evident at the age of 7. She underwent cataract extraction with posterior chamber lens implantation. We are reporting a case of mitochondrial respiratory chain defect with multiorgan involvements including bilateral progressive cataract, an uncommon ocular manifestation. Ophthalmologic evaluation is highly recommended not to overlook the possible ocular manifestations in mitochondrial disorders.

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HQNO-sensitive NADH:Quinone Oxidoreductase of Bacillus cereus KCTC 3674

  • Kang, Ji-Won;Kim, Young-Jae
    • BMB Reports
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    • v.40 no.1
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    • pp.53-57
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    • 2007
  • The enzymatic properties of NADH:quinone oxidoreductase were examined in Triton X-100 extracts of Bacillus cereus membranes by using the artificial electron acceptors ubiquinone-1 and menadione. Membranes were prepared from B. cereus KCTC 3674 grown aerobically on a complex medium and oxidized with NADH exclusively, whereas deamino-NADH was determined to be poorly oxidized. The NADH oxidase activity was lost completely by solubilization of the membranes with Triton X-100. However, by using the artificial electron acceptors ubiquinone-1 and menadione, NADH oxidation could be observed. The activities of NADH:ubiquinone-1 and NADH:menadione oxidoreductase were enhanced approximately 8-fold and 4-fold, respectively, from the Triton X-100 extracted membranes. The maximum activity of FAD-dependent NADH:ubiquinone-1 oxidoreductase was obtained at about pH 6.0 in the presence of 0.1M NaCl, while the maximum activity of FAD-dependent NADH:menadione oxidoreductase was obtained at about pH 8.0 in the presence of 0.1M NaCl. The activities of the NADH:ubiquinone-1 and NADH:menadione oxidoreductase were very resistant to such respiratory chain inhibitors as rotenone, capsaicin, and $AgNO_3$, whereas these activities were sensitive to 2-heptyl-4-hydroxyquinoline-N-oxide (HQNO). Based on these results, we suggest that the aerobic respiratory chain-linked NADH oxidase system of B. cereus KCTC 3674 possesses an HQNO-sensitive NADH:quinone oxidoreductase that lacks an energy coupling site containing FAD as a cofactor.

Investigation of post - weaning atrophic pig diseases in swine breeding complex in Jeonbuk - Iksan (전북 익산 양돈단지 이유 후 위축자돈 질병 조사)

  • Chu, Keum-Suk;Jo, Young-Suk
    • Korean Journal of Veterinary Service
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    • v.30 no.1
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    • pp.85-93
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    • 2007
  • The purpose of this study was to investigate the infection situation of several diseases (post-weaning atrophic pigs) such as porcine reproductive and respiratory syndrome (PRRS) in swine breeding complex in Jeonbuk-Iksan. From February to October in 2006, a total of 28 swine samples (6-10 week old) were collected from 6 farms and examined by polymerase chain reaction(PCR) and clinical signs. In the rate of single infection, pneumonia was top (32.1%), followed by salmonellosis (14.2%)and Glasser's disease (10.7%) and double infection pneumonia/Glasser's disease (17.8%) was detected. PCR was detected of PCV 2 from 28 (100.0%) and PPV 6 (21.4%), PRRS PORF6 10 (35.7%) and POR7 11 (39.2%), but HC and AD was not detected. The results suggest that PCV 2 is complex infection PRRS, PPV and bacterial disease.

HQNO-sensitive NADH:DCIP Oxidoreductase of a Pathogenic Bacillus cereus Causing β-Hemolysis (Beta hemolysis 유발 병원균 Bacillus cereus의 HQNO-sensitive NADH:DCIP oxidoreductase)

  • Kim Young-Jae;Park Ki-Tae
    • Journal of Life Science
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    • v.16 no.3 s.76
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    • pp.505-509
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    • 2006
  • Membranes prepared from Bacillus cereus KCTC 3674, grown aerobically on a complex medium, oxidized NADH exclusively, whereas deamino-NADH was little oxidized. The respiratory chain-linkedNADH oxidase system exhibited an apparent $K_m$ value of about $65\;{\mu}M$ for NADH. Interestingly, the activity of NADH:DCIP oxidoreductase on NADH oxidase system was decreased remarkably by $Na^+$ or $K^+$, and its optimal pH was 5.5. The activity of NADH:DCIP oxidoreductase was very resistant to the respiratory chain inhibitors such as rotenone, capsaicin, and $AgNO_3$, whereas it was inhibited by about 40% with $40{\mu}M$ 2-heptyl-4-hydroxyquinoline-N-oxide (HQNO). From the results, we suggest the possibility that the aerobic respiratory chain-linked NADH oxidase system of B. cereus KCTC 3674 may possess the HQNO-sensitive NADH:DCIP oxidoreductase lacking an energy coupling site.

Properties of the Membrane-Bound NADH;Menadione Oxidoreductase in the Aerobic Respiratory Chain of Bacillus cereus (Bacillus cereus의 호기적 호흡쇄에 있어서 세포질막 내에 존재하는 NADH;menadione oxidoreductase의 특성)

  • Kang, Ji-Won;Kim, Young-Jae
    • Journal of Life Science
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    • v.18 no.3
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    • pp.418-421
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    • 2008
  • Membranes prepared from Bacillus cereus KCTC 3674, grown aerobically on a complex medium, oxidized NADH exclusively, whereas deamino-NADH was little oxidized. The respiratory chain-linked NADH oxidase system exhibited an apparent $K_m$ value of approximately 65 ${\mu}M$ for NADH. On the other hand, the enzymatic properties of the NADH: menadione oxidoreductase of NADH oxidase system were examined. The maximum activity of NADH: menadione oxidoreductase was obtained at pH 9.5 in the presence of 0.1 M KCl (or NaCl). The NADH: menadione oxidoreductase activity was very resistant to the respiratory chain inhibitors such as rotenone, capsaicin, and $AgNO_3$. Interestingly, the activity was stimulated by the 2-heptyl-4-hydroxyquinoline-N-oxide (HQNO).

Target engagement of ginsenosides in mild cognitive impairment using mass spectrometry-based drug affinity responsive target stability

  • Zhu, Zhu;Li, Ruimei;Qin, Wei;Zhang, Hantao;Cheng, Yao;Chen, Feiyan;Chen, Cuihua;Chen, Lin;Zhao, Yunan
    • Journal of Ginseng Research
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    • v.46 no.6
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    • pp.750-758
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    • 2022
  • Background: Mild cognitive impairment (MCI) is a transitional condition between normality and dementia. Ginseng is known to have effects on attenuating cognitive deficits in neurogenerative diseases. Ginsenosides are the main bioactive component of ginseng, and their protein targets have not been fully understood. Furthermore, no thorough analysis is reported in ginsenoside-related protein targets in MCI. Methods: The candidate protein targets of ginsenosides in brain tissues were identified by drug affinity responsive target stability (DARTS) coupled with label-free liquid chromatography-mass spectrometry (LC-MS) analysis. Network pharmacology approach was used to collect the therapeutic targets for MCI. Based on the above-mentioned overlapping targets, we built up a proteineprotein interaction (PPI) network in STRING database and conducted gene ontology (GO) enrichment analysis. Finally, we assessed the effects of ginseng total saponins (GTS) and different ginsenosides on mitochondrial function by measuring the activity of the mitochondrial respiratory chain complex and performing molecular docking. Results: We screened 2526 MCI-related protein targets by databases and 349 ginsenoside-related protein targets by DARTS. On the basis of these 81 overlapping genes, enrichment analysis showed the mitochondria played an important role in GTS-mediated MCI pharmacological process. Mitochondrial function analysis showed GTS, protopanaxatriol (PPT), and Rd increased the activities of complex I in a dose-dependent manner. Molecular docking also predicted the docking pockets between PPT or Rd and mitochondrial respiratory chain complex I. Conclusion: This study indicated that ginsenosides might alleviate MCI by targeting respiratory chain complex I and regulating mitochondrial function, supporting ginseng's therapeutic application in cognitive deficits.