• 제목/요약/키워드: mitochondrial enzymes

검색결과 136건 처리시간 0.026초

식물 미토콘드리아에 대한 Superoxide독성의 생화학적 측면 (Biochemical Aspect of Superoxide Toxicity to Plant Mitochondria)

  • 정진;인만진
    • 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.

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Relationship between Genetic Variants of Mitochondrial DNA and Growth Traits in Hanwoo Cattle

  • Jeon, G.J.;Chung, H.Y.;Choi, J.G.;Lee, M.S.;Lee, C.W.;Park, J.J.;Ha, J.M.;Lee, H.K.;Sung, H.H.
    • Asian-Australasian Journal of Animal Sciences
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    • 제18권3호
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    • pp.301-307
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    • 2005
  • Genetic variants of Hanwoo mtDNA in the region of cytochrome oxidase subunit I, II and III complex were detected using restriction enzymes. PCR primers were designed based on the bovine mtDNA sequence, and 6 primer sets (Mt4, Mt5, Mt6, Mt7, Mt8 and Mt9) were used. A total of 20 restriction enzymes were used, and 6 restriction enzymes, which were Hinf I, Pvu II, Rsa I, Eco RI, Bgl II, and Msp I, showed genetic polymorphisms. Significant associations between genetic variants and weight traits were observed at WT15 (p<0.05) and WT18 (p<0.01) with Pvu II for Mt9, Bgl II for Mt6 and Rsa I for Mt8 segments in the region of cytochrome oxidase subunit complex. Significant associations were also observed at Mt9-Pvu II and Mt6-Bgl II segments for WT9 (p=0.01), WT12 (p=0.02), respectively. These results suggest that genetic variants of mtDNA in the region of cytochrome oxidase subunit complex may be candidate segments for improvement of animal growth as weight traits.

Effect of Ganoderma Lucidum Pharmacopuncture on Chronic Liver Injury in Rats

  • Jang, Sun Hee;Yoon, Hyun Min;Kim, Bum Hoi;Jang, Kyung Jeon;Kim, Cheol Hong
    • Journal of Acupuncture Research
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    • 제32권1호
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    • pp.13-22
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    • 2015
  • Objectives : Alcohol-related liver disease is a major cause of morbidity and mortality worldwide. The present study was undertaken to determine whether Ganoderma lucidum pharmacopuncture(GLP) could protect against chronic liver injury induced by ethanol intoxication in rats. Methods : Sprague-Dawley rats were divided into 4 groups: normal, control, normal saline pharmacopuncture(NP), and GLP, with 8 animals in each. Each group, except normal, received ethanol orally. The NP and GLP groups were treated daily with NP and GLP respectively. The control group was not treated. All rats except the normal group were intoxicated for 4 weeks by oral administration of EtOH(6 g/kg BW). Two acupuncture points were used: Qimen($LR_{14}$) and Taechung($LR_3$). Body weight, histopathological analysis, liver function, activities of antioxidant enzymes, and immunohistochemistry were assessed. Results : GLP reduced the histological changes due to chronic liver injury induced by EtOH and significantly reduced the increase in the alanine aminotransferase(ALT) and aspartate aminotransferase(AST) enzymes. It significantly reversed the superoxide dismutase(SOD) and the catalase activities(CAT). It also significantly decreased BAX and increased Bcl-2 immunoreactivity expression. Conclusions : This study showed the protective efficacy of GLP against EtOH-induced chronic liver injury in SD rats by modulating ethanol metabolizing enzymes activity, attenuating oxidative stress, and inhibiting mitochondrial damage-mediated apoptosis.

Conversion of Apricot Cyanogenic Glycosides to Thiocyanate by Liver and Colon Enzymes

  • Lee, Ji-Yeon;Kwon, Hoon-Jeong
    • Toxicological Research
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    • 제25권1호
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    • pp.23-28
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    • 2009
  • Some of the edible plants like apricot kernel, flaxseed, and cassava generate hydrogen cyanide (HCN) when cyanogenic glycosides are hydrolyzed. Rhodanese (thiosulfate: cyanide sulfurtransferases of TSTs; EC: 2.8.1.1) is a sulfide-detoxifying enzymes that converts cyanides into thiocyanate and sulfite. This enzyme exists in a liver and kidneys in abundance. The present study is to evaluate the conversion of apricot cyanogenic glycosides into thiocyanate by human hepatic (HepG2) and colonal (HT-29) cells, and the induction of the enzymes in the rat. The effects of short term exposure of amygdalin to rats have also been investigated. Cytosolic, mitochondrial, and microsomal fractions from HepG2 and HT-29 cells and normal male Spraque-Dawley rats were used. When apricot kernel extract was used as substrate, the rhodanese activity in liver cells was higher than the activity in colon cells, both from established human cell line or animal tissue. The cytosolic fractions showed the highest rhodanese activity in all of the cells, exhibiting two to three times that of microsomal fractions. Moreover, the cell homogenates could metabolize apricot extract to thiocyanate suggesting cellular hydrolysis of cyanogenic glycoside to cyanide ion, followed by a sulfur transfer to thiocyanate. After the consumption of amygdalin for 14 days, growth of rats began to decrease relative to that of the control group though a significant change in thyroid has not been observed. The resulting data support the conversion to thiocyanate, which relate to the thyroid dysfunction caused by the chronic dietary intake of cyanide. Because Korean eats a lot of Brassicaceae vegetables such as Chinese cabbage and radish, the results of this study might indicate the involvement of rhodanese in prolonged exposure of cyanogenic glycosides.

Thiol Methyltransferase Activity in Cholestatic Rat Liver Induced by Commom Bile Duct Ligation

  • Joo, Il;Kwak, Chun-Sik;Yoon, Chong-Guk
    • 대한의생명과학회지
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    • 제10권1호
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    • pp.43-48
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    • 2004
  • Changes of thiol methyltransferase (TMT) activity in cholestatic rat liver were studied. Hepatic subcellular and serum TMT activities were determined in cholestatic rat induced by common bile duct (CBD) ligation over a period 28 days. The mitochondrial and microsomal TMT activities in cholestatic rat liver were found to be significantly increased between the 1st and the 28th day after CBD ligation. The TMT activity in serum was significantly increased throughout the experiments. The Vmax values of the above hepatic TMT in cholestatic rat were significantly increased at the 7th day after CBD ligation. However, the Km values of the above hepatic enzymes did not vary in all the experimental groups. Therefore, the results indicate that the biosynthesis of TMT was increased in cholestatic rat liver. The elevated serum TMT activity is most likely caused by increased hepatocytes membrane permeability due to cholestasis mediated liver cell necrosis.

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Effects of Intravenous Administration of Taurocholate on Hepatic Aryl Sulfotransferase Activity in Cholestatic Rats

  • ;;곽춘식
    • 대한의생명과학회지
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    • 제11권1호
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    • pp.37-43
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    • 2005
  • The possible mechanisms of increased aryl sulfotransferase (AST) isozymes activities in cholestatic rat liver were studied. Hepatic AST-I, II and -III, IV activities were determined from the experimental rats with common bile duct ligation (CBDL). The Michaelis-Menten constants in these hepatic enzymes were also measured. The activities of mitochondrial AST-I, II and -III, IV, and microsomal AST-III, IV as well as their Vmax values were found to be increased significantly in CBDL plus taurocholic acid (TCA) injected group than in the control group, such as CBDL alone groups. However, their Km values in the experimental groups did not vary. The results suggest that TCA stimulates biosynthesis of the AST in the liver.

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Effects of Intravenous Administration of Taurocholate on Hepatic Monoamine Oxidase A and B Activities in Cholestatic Rats

  • Do Jun-Young;Kwak Chun-Sik
    • 대한의생명과학회지
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    • 제10권4호
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    • pp.421-427
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    • 2004
  • The possible mechanisms of decreased monoamine oxidase (MAO) A and B activities in cholestatic rat liver were studied. Hepatic and serum MAG activities were determined from the experimental rats with common bile duct ligation (CBDL). The Michaelis-Menten constants in these hepatic enzymes were also measured. The activities of mitochondrial MAO A and B, and mircosomal MAO B as well as their Vmax values were found to be decreased significantly in CBDL plus taurocholic acid (TCA) injected group than in the control group, such as CBDL alone groups. However, their Km values in the experimental groups did not vary. Serum MAO activity increased significantly in the CBDL plus TCA injected group than in the control group. The above results suggest that TCA represses biosynthesis of the MAO in the liver. The elevated activity of the serum MAO is believed to be caused by the increment of membrane permeability ofhepatocytes upon TCA mediated liver cell necrosis.

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금은화에서 분리한 Caffeic Acid의 신경세포보호 활성 (Neuroprotective Activity of Caffeic Acid Isolated from Lonicera japonica)

  • 손예림;마충제
    • 생약학회지
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    • 제51권1호
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    • pp.30-35
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    • 2020
  • We previously reported that caffeic acid isolated from Lonicera japonica showed potent neuroprotective activities against glutamate injured neuronal cell death in primary cortical cells. In this study, we tried to confirm the neuroprotective activity in glutamate injured HT22 cells and elucidate mechanisms of neuroprotective action of caffeic acid. We used glutamate induced HT22 cell death as a bioassay system. The compound decreased reactive oxygen species increased by high concentration of glutamate treatment in HT22 cells. Also, Ca2+ concentration was decreased by this compound. This compound made mitochondrial membrane potential maintain to normal condition. This also affected anti-oxidative enzymes and glutathione contents. Treatment of this compound increased not only glutathione reductase and peroxidase to the control level and also amount of glutathione, an endogeneous antioxidant. These experimental results showed that caffeic acid isolated from L. japonica exerted potent neuroprotective activity through the anti-oxidative pathway.

Phylogenetic Analysis of Trichaptum Based on the RFLP of PCR-Amplified DNAs

  • Ko, Kwan-Soo;Jung, Hack-Sung
    • Journal of Microbiology
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    • 제34권4호
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    • pp.295-299
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    • 1996
  • To infer phylogenetic relationships between species of Trichaptum (Polyporaceae), RFLP analyses of PCR-amplified DNAs were accomplished. Regions coding for ITSs of nuclear SSU rRNA genes and for mitochondrial SSU rRNA genes from thirteen strains of four Trichaptum species (T. abietinum, T. biforme, T. fusco-violaceum, and T. laricinum) were amplified and digested with eight restriction enzymes. All the fragmentation patterns were characterized and coded as 0/1 for the absence/presence of fragments. A phylogenetic tree based on the combined data sets was constructed using the Dollo parsimony method. While every two strains of T. abietinum, T. biforme, T. fusco-violaceum, and T. laricinum formed an independent group, the other strains of T. abietimum and T. fusco-violaceum made mixed groupings among compared strains. It is inferred that T. abietinum and T. fusco-violaceum have more variations, possibly geographic or physiological ones, than other species in the genus.

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Effects of Polyacetylenes from Panax ginseng on Some Microsomal and Mitochondrial Enzymes

  • Kim, Young-Sook;Kim, Shin-Il;Hahn, Dug-Ryong
    • 생약학회지
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    • 제20권3호
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    • pp.154-161
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    • 1989
  • Effects of panaxydol, panaxynol and panaxytriol isolated from Panax ginseng C.A. Meyer on some enzyme activities were determined. Activities of ATPase, membrane-bound enzyme from Sarcoma 180 and rat liver were slightly inhibited by panaxydol. Activities of 5'-nucleotidase, membrane-bound enzyme and succinate cytochrome c reductase in mitochonidria from sarcoma 180 and rat livers were significantly inhibited in a dose-dependent manner by panaxynol. The inhibitory effects of panaxydol and panaxynol on succinate cytochrome c reductase activities were more potent than those on 5'-nucleotidase activities and panaxynol was found to be a very potent inhibitor of succinate cytochrome c reductase. Activities of glucose-6-phosphatase in endoplasmic reticulum from Sarcoma 180 and rat livers were not affected by all three polyacetylenes. These results suggested that the inhibitory effects of panaxydol and panaxynol on enzyme activities might contribute to their biological activities.

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