• BMB Reports
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• 제29권4호
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• pp.300-307
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• 1996

ATP and ADP are potential regulators of mitochondtial respiration and at physiological concentrations they affect the rate of electron transfer between cytochrome c and cytochrome c oxidase. The electron transfer, however, depends on the electrostatic interaction between the two proteins. In order to exclude any nonspecific ionic effects by these polyvalent nucleotides, we used 2'-O-(2,4,6)trinitro(TNP)-derivatives of ATP and ADP which have three orders of magnitude higher affinity for cytochrome c oxidase. A simple titration of the fluorescence intensity of TNP by cytochrome c oxidase showed a binding stoichiometry of 2:1 cytochrome c:cytochrome c oxidase. Higher ionic strength was required for TNP-ATP than for TNP-ADP to be dissociated from cytochrome c oxidase, indicating that the negative charges on the phosphate group are at least partially responsible for the binding. In both spectrophotometric and polarographic assays, addition of ATP (and ADP to a less extent) showed an enhanced cytochrome c oxidase activity. Both electron paramagnetic resonance and fluorescence spectra indicate that there is no Significant change in the cytochrome c-cytochrome c oxidase interaction. Instead, reduction levels of the cytochromes at steadystate suggest that the increased activity of nucleotide-bound cytochrome c oxidase is due to faster electron transfer from cytochrome ${\alpha}$ to cytochrome ${\alpha}_3$, which is known to be the fate limiting step in the oxygen reduction by cytochrome c oxidase.

• Korean Journal of Acupuncture
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• 제36권4호
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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.

• Korean Journal of Acupuncture
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• 제37권1호
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• pp.37-45
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• 2020

Objectives : Mitochondria are typically known as intracellular double membrane-bound structures that supply energy for intracellular metabolism including Krebs cycle and beta-oxidation. Also, acupuncture has been known to stimulate the flow of energy. To explore the effect of acupuncture on the mitochondrial respiratory chain activities in rat's heart and kidneys, the activities of mitochondrial respiratory chain complexes I to IV were observed. Methods : The rats were divided into 11 groups; Normal (no acupuncture treatment and under anesthesia for 10 min), heart meridian five-transport-points (acupuncture treatment at HT9, HT8, HT7, HT4 and HT3 under anesthesia for 10 min), and kidney meridian five-transport-points (acupuncture treatment at KI1, KI2, KI3, KI7 and KI10 under anesthesia for 10 min). All rats were sacrificed and the heart and kidneys were examined for the changes of respiratory chain activities. Results : Acupuncture at HT7 increased the activity of succinate dehydrogenase; acupuncture at KI2 increased the activity of ubiquinol cytochrome C oxidoreductase; and acupuncture at HT9, HT8, HT3 and KI1 increased activities of cytochrome C oxidase. Conclusions : Acupuncture assists mitochondrial repiratory chain activity via the Cytochrome C oxidase signaling pathway in heart and kidney of rats.

• Parasites, Hosts and Diseases
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• 제45권3호
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• pp.181-190
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• 2007

The phylogenie relationships existing among 14 parasitic Platyhelminthes in the Republic of Korea were investigated via the use of the partial 28S ribosomal DNA (rDNA) D1 region and the partial mitochondrial cytochrome c oxidase subunit 1 (mCOI) DNA sequences. The nucleotide sequences were analyzed by length, G + C %, nucleotide differences and gaps in order to determine the analyzed phylogenie relationships. The phylogenie patterns of the 28S rDNA D1 and mCOI regions were closely related within the same class and order as analyzed by the PAUP 4.0 program, with the exception of a few species. These findings indicate that the 28S rDNA gene sequence is more highly conserved than are the mCOI gene sequences. The 28S rDNA gene may prove useful in studies of the systematics and population genetic structures of parasitic Platyhelminthes.

• Journal of the Korean Wood Science and Technology
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• 제38권2호
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• pp.135-139
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• 2010

Reticulitermes speratus is commonly found in Asia, including Korea and Japan. We recently analyzed the 5' region of mitochondrial cytochrome c oxidase subunit I to perform a phylogenetic analysis of R. speratus KMT1, isolated in Seoul, Korea. Our results, using COXI, suggest that the taxonomy of R. speratus should be reconsidered with regard to the subgenus group. A similar phylogenetic analysis by COXI and COXII demonstrated the reliability of COXI genetic information in a molecular phylogenetic analysis of termites.

• BMB Reports
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• 제28권3호
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• pp.254-260
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• 1995

Cytochrome oxidase was purified from bovine-heart mitochondria and its enzymatic properties were examined. The purified cytochrome oxidase was identified by its absorption spectrum and chromatogram through gel filtration. The specific activity, purification degree and yield of purified cytochrome oxidase were 18 nmol/mg/ml/min, 24.83 fold and 0.93%, respectively. The activity of the enzyme assayed by a ferrocytochrome $c-O_2$ system was optimized at $25^{\circ}C$ and pH 6.5. Examining the effect of nonionic detergents established that cytochrome oxidase was deactivated by Triton X-100. The oxidase was activated by Tween 80 and deactivated by Tween 20. The Michaelis constant and maximum velocity of the oxidase for ferrocytochrome c were 0.032~0.044 mM and 0.019~0.021 mM/min, respectively. After adaption to basal diet for a week, experimental diets containing 6 mg Cu/kg, or zero mg Cu/kg, or 12 mg Cu/kg were fed to a control group, a copper-free group and a copper-rich group of Sprague-Dawley rats, respectively, for 4 weeks. The specific activities assayed for the ferrocytochrome $c-O_2$ system of isolated cytochrome oxidase from the rat liver of control, copper-free, and copper-rich group were 1.00, 1.19, and 0.878 nmol/mg/ml/min, respectively. Their degrees of purification were 11.38, 10.82 and 8.78 fold, respectively. The specific activities for liver and heart mitochondrial cytochrome oxidase of copper-free/copper-rich groups assayed using the ferrocytochrome $c-O_2$ system were 81.4% and 96.4%/64.1% and 61.1%, respectively, compared with those of the control.

• Parasites, Hosts and Diseases
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• 제42권2호
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• pp.71-75
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• 2004

To determine the molecular phylogenie location of Plagiorchis muris, 28S D1 ribosomal DNA (rDNA) and mitochondrial cytochrome C oxidase subunit I (mtCOI) were sequenced and compared with other trematodes in the family Plagiorchiidae. The 28S D1 tree of P. muris was found to be closely related to those of P. elegans and other Plagiorchis species. And, the mtCOI tree also showed that P. muris is in a separate clade with genus Glypthelmins. These results support a phylogenie relationship between members of the Plagiorchiidae, as suggested by morphologic features.

• The Korean Journal of Physiology and Pharmacology
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• 제10권4호
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• pp.207-212
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• 2006

Mitochondrial permeability transition has been shown to be involved in neuronal cell death. Mitochondrial monoamine oxidase (MAO)-B is considered to play a part in the progress of nigrostriatal cell death. The present study examined the effect of MAO inhibitors against the toxicity of 1-methyl-4-phenylpyridinium $(MPP^+)$ in relation to the mitochondrial permeability transition. Chlorgyline (a selective inhibitor of MAO-A), deprenyl (a selective inhibitor of MAO-B) and tranylcypromine (nonselective inhibitor of MAO) all prevented cell viability loss, cytochrome c release, caspase-3 activation, formation of reactive oxygen species and depletion of GSH in differentiated PC12 cells treated with $500\;{\mu}M$$MPP^+$. The MAO inhibitors at $10\;{\mu}M$ revealed a maximal inhibitory effect and beyond this concentration the inhibitory effect declined. On the basis of concentration, the inhibitory potency was tranylcypromine, deprenyl and chlorgyline order. The results suggest that chlorgyline, deprenyl and tranylcypromine attenuate the toxicity of $MPP^+$ against PC12 cells by suppressing the mitochondrial permeability transition that seems to be mediated by oxidative stress.

• Applied Biological Chemistry
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• 제32권1호
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• pp.23-29
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• 1989

soybean hypocotyl에서 분리한 미토콘드리아로부터 submitochondrial particles와 matrix 단백질 추출액을 준비하고 전기분해법으로 제조한 superoxide를 처리하여 malate dehydrogenase 및 cytochrome C oxidase의 불활성화와 mitochondrial membrane의 과산화를 각각 조사하였다. 막에 결합되어 있는 cytochrome C oxidase나 수용액상태의 malate dehydrogenas는 모두 $O^{-}_{2}$에 대해 매우 민감하게 불활성화되었다. 즉 dismutation 반응이 빠르게 진행되어 실질적으로 효소의 불활성화에 기여하게 될 농도는 대단히 낮을 것으로 추정되는 $O^{-}_{2}$의 명목상 처리농도 1.4mM 전후에서 두 효소는 그 활성을 완전히 상실하였다. 한편 malondialdehyde의 생성을 지표로 하여 측정된 membrane 과산화는 인지질로서만 이루어진 liposome의 경우보다는 다소 낮은 수준이었으나 무시할 수는 없는 정도였다. mitochondrial membrane의 과산화가 상대적으로 억제된 것은 막에 결합되어 있는 항산화제 및 단백질들에 의한 $O^{-}_{2}$소거효과에 기인하였으리라 해석된다. 식물 미토콘드리아의 대표적인 대사과정인 TCA cycle과 호흡전자전달반응의 성분효소들인 malate dehydrogenase와 cytochrome C oxidase가 불활성화되었고 membrane이 과산화 되었다는 사실은, 식물의 냉해와 광피해 발현기작에서 공히공통적인 화학적 인자로 인정되는 $O^{-}_{2}$의 과잉생성 및 축적이 그것의 주 생성처인 미토콘드리아의 생화학적 기능과 구조에 미칠수 있는 파괴적 효과를 적절히 지시하는 것이다.

• ALGAE
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• 제33권1호
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• pp.49-54
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• 2018

Red algal mitochondrial genomes (mtDNAs) can provide useful information on species identification. mtDNAs of Pyropia / Porphyra (Bangiales, Rhodophyta) have shown diverse variation in their size and gene structure. In particular, the introns and intronic open reading frames found in the ribosomal RNA large subunit gene (rnl) and cytochrome c oxidase subunit 1 gene (cox1) significantly vary the mitochondrial genome size in Pyropia / Porphyra species. In this study, we examined the exon / intron structure of rnl and cox1 genes of Pyropia yezoensis at the intraspecific level. The combined data of rnl and cox1 genes exhibited 12 genotypes for 40 P. yezoensis strains, based on the existence of introns. These genotypes were more effective to identify P. yezoensis strains in comparison to the traditional DNA barcode cox1 marker (5 haplotypes). Therefore, the variation in gene structure of rnl and cox1 can be a novel molecular marker to discriminate the strains of Pyropia species.