• BMB Reports
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• 제33권3호
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• pp.285-288
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• 2000

Ferricytochrome c was artificially made to receive the aqueous electrons evolved through the influence of illuminated chloroplast. This ferricytochrome c, which was bombarded by electrons, was reduced to ferrocytochrome c by making sure that a certain cytochrome is reduced. This may require an electronic attack that is created by the chloroplast inside the plant cell. The possibility of reversing the oxidation of ferrocytochrome c by cytochrome oxidase was examined using a contrived redox system composed of cytochrome oxidase, ferricytochrome c and chloroplast with illumination. We recognized that the oxidase is unserviceable for the reversibleness in spite of the existence of chloroplast.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 1999년도 학술발표회 진행표 및 논문초록
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• pp.46-46
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• 1999

Positively charged cytochrome c interacts with the negatively charged mitochondrial inner membrane. This interaction induces conformational changes in bound cytochrome c. In order to estimate the effect of cytochrome c-membrane interaction on the mitochondrial electron transfer, we have investigated oxidation of ferrocytochrom c in the presence of anionic phospholipids.(omitted)

• Toxicological Research
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• 제4권1호
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• pp.23-35
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• 1988

The role of calcium in the production of oxygen radical which causes reperfusion damage of ischemic heart has been examined. The reperfusion damage was indrced in isolated Langendorff perfused rat hearts by aortic clamping for 60 min followed by reperfusion with oxygenated Krebs-Henseleit solution with or without 1.25 mM $CaCl_2.$ On reperfusion of the ischemic hearts with the calcium containing solution, the release of cytosolic enzymes (LDH and CPK) increased abruptly. These increased release of enzymes were significantly inhibited by additions of oxygen radical scavengers (SOD, 5,000 U; catalase, 12,500 U) into the reperfusion solution. In the hearts isolated from rats pretreated with allopurinol(20 mg/kg orally, 24 hr and 2 hr prior to the experiments), the levels of enzymes being released during reperfusion were significantly lower than that of the control. However, in the hearts perfused with the calcium-free but oxygenated solution, the increase in the release of cytosolic enzymes during reperfusion was neither inhibited by oxygen radical scavengers nor by allopurinol pretreatment. For providing the evidence of oxygen radical generation during the reperfusion of ischemic hearts in situ, the SOD-inhibitable reduction of exogenously administered ferricytochrome C was measured. In the hearts perfused with the calcium containing solution, the SOD-inhibitable ferricytochrome C reduction increased within the first minute of reperfusion, and was almost completely inhibited by allopurinol pretreatment. When the heart was perfused with the calcium free solution, however, the reduction of ferricytochrome C was not only less than that in the calcium containing condition, but also was not so completely inhibited by allopurinol pretreatment. By ischemia, xanthine oxidase (XOD) in the ventricular tissue was changed qualitatively, but not quantitatively. In the heart made ischemic with the calcium containing condition, the oxygen radical producing O-form of XOD increased, while the D- and D/O-form decreased. However, in the ischemic heart reperfused with the calcium free condition, the D/O-form of XOD was elevated without significant increase in O-form of the enzyme. It is suggested from these results that the calclum may play a contributing role in the genesis of reperfusion damage by promoting the conversion of xanthine oxidase from the D/O-form to the oxygen radical producing O-form in the ischemic myocardium.

• Journal of Chest Surgery
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• 제21권5호
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• pp.803-815
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• 1988

The present experiments were performed to confirm the hypothesis that xanthine oxidase[XOD], as a source and mechanism of oxygen radical production, plays an important role in the genesis of the reperfusion injury of ischemic myocardium. The experimental ischemic-reperfusion injury was induced in isolated, Langendorff preparations of rat hearts by 60 min. Of global ischemia with aortic clamping followed by 20 min. of reperfusion with oxygenated Krebs-Henseleit solution[pH 7.4, 37*C]. The results were as follows: 1. The releases of creatine phosphokinase and a lipid peroxidation product, malondialdehyde[MDA] into the coronary effluent were abruptly increased upon reperfusion of ischemic hearts. The increases of the enzyme and MDA were suppressed significantly in the hearts removed from rats pretreated with allopurinol, a specific XOD inhibitor[20mg/kg, oral, 24 hrs and 2 hrs before study]. This effect of allopurinol was comparable to that of oxygen radical scavengers, superoxide dismutase[5, 000U] and catalase[12, 500 U]. 2. The increased SOD-inhibitable reduction of ferricytochrome C, which was infused to the hearts starting with reperfusion, was significantly suppressed in allopurinol pretreated hearts. 3. Activities of myocardial XOD were compared in the normal control hearts and the ischemic ones. Total enzyme activities were not different in both hearts. However, comparing with the control, the ischemic ones showed higher activity in 0-form and lower activities in D-form and D/O-form. 4. In the ischemic hearts, phenylmethylsulfonyl fluoride, a serine protease inhibitor, prevented significantly the increase of 0-form and the decreases of D and D/O-form, while thiol reagents did not affect the changes of the enzyme. 5. The increase of 0-form and the decreases of D and D/0-form were not significant in both calcium-free perfused and pimozide, a calmodulin inhibitor, treated ischemic hearts. 6. The SOD-inhibitable reduction of ferricytochrome C were suppressed by PMSF and pimozide treatment as well as by calcium-free perfusion. It is suggested from these results that in the ischemic rat myocardium, xanthine oxidase is converted to oxygen radical producing 0-form by calcium, calmodulin-dependent proteolysis and plays a contributing role in the genesis of ischemic-reperfusion injury by producing oxygen free radicals.

• Bulletin of the Korean Chemical Society
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• 제21권4호
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• pp.412-418
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• 2000

Association of cytochrome c with anionic membranes involved both electrostatic and hydrophobic interactions and their relative contributions depended on the physical state of the membrane and the redox state of cyto-chromec.Hydrophobic interaction was favored by the membranes in gel phase, by the membranes with a large curvature, and by the membranes with a high surface charge density. Ferrocytochrome c was less dissociable by NaCl than ferricytochrome c suggesting that a lower protein stability is beneficial for hydrophobic interac-tion.Hydrophobic interaction induced larger structural perturbations on cytochrome c as monitored by the loss of the Fe-Met bond and by the increase in the distance between heme and Trp-59. When bound to anionic mem-branes,spin-labeled cytochrome c showed an electron paramagnetic resonance spectrum with two or more components, providing a direct evidence for multiple conformations of bound cytochrome c.

• 대한수의학회지
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• 제38권2호
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• pp.273-279
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• 1998

The ability of bovine intact red blood cells to scavenge superoxide and hydrogen peroxide by superoxide dismutase, catalase and glutathione peroxidase was investigated. Intact red cells(up to 0.4%) suspensions did not inhibit ferricytochrome c reduction by superoxide in the superoxide generating system. On the other hand, intact red cell(0.4%) suspensions almost completely inhibit ferrocytochrome c oxidation by hydrogen peroxide. The ability of intact red cells to scavenge hydrogen peroxide was mainly attributed to either membrane bound catalase or glutathione peroxidase. The scavenge of hydrogen peroxide by 0.1~0.2% intact red cells showed a trend of dependence on mainly glutathione peroxidase. However, at blood cell concentration higher than 0.3%, the process depended upon peroxidase-independent scavengers like catalase. Enhancement of ferrocytochrome c oxidation by red cells treated with aminotriazole proved that the protection against hydrogen peroxide was due to catalase, while the protection in the presence of glutathione indicated scavenging effect of glutathione peroxidase against hydrogen peroxide.

• 대한약리학회지
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• 제31권3호
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• pp.345-353
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• 1995

Harmaline을 포함한 ${\beta}-Carboline$ 알카로이드들은 마이크로조움의 효소성 또는 비효소성 지질 과산화를 억제한다고 제시되고 있으나, 이들의 항산화 작용기전은 분명하지 않다. 본 연구에서는 $Fe^{2+}$와 $H_2O_2$에 의한 hyaluronic acid, 지질과 콜라젠의 산화성 손상에 있어 harmaline과 harmalol의 항산화 능력을 관찰하였다. 또한 반응성 산소대사물에 대한 이들의 제거작용을 조사하였다. Harmaline, harmalol, superoxide dismutase, catalase와 DMSO는 $Fe^{2+}$와 $H_2O_2$에 의한 hyaluronic acid의 변성과 $Fe^{2+}$에 의한 지질 과산화를 억제하였다. 이들 반응에서 DABCO는 hyaluronic acid의 변성을 억제하였으나 지질 과산화에 영향을 나타내지 않았다. ${\beta}-Carboline$은 $Fe^{2+}$, $H_2O_2$와 ascorbic acid에 의한 cartilage collagen의 변성을 억제하였다. Superoxide dismutase에 의하여 억제되는 $Fe^{2+}$의 자가산화에 따른 ferricytochrome c의 환원은 harmaline과 harmalol의 영향을 받지 않았다. 또한 이들은 $H_2O_2$에 대하여 분해작용을 나타내지 않았다. $Fe^{2+}$와 $H_2O_2$의 존재하에서 OH 생성은 harmaline, harmalol과 DMSO에 의하여 억제되었다. Harmaline과 harmalol은 반응성 산소대사물인 OH 과 아마도 철이온-산소 복합체에 대한 제거작용으로써 $Fe^{2+}$와 $H_2O_2$에 의한 hyaluronic acid, 지질과 콜라젠의 산화성 손상을 억제하고, 항산화 능력을 나타낼 것으로 추정된다.

• Journal of Pharmaceutical Investigation
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• 제22권3호spc1호
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• pp.65-76
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• 1992

The superoxide dismutase (SOD)-mimetic activities of copper complexes of a series of salicylic acid (SA) analogs were tested and compared to the activity of bovine erythrocyte SOD using ferricytochrome c reduction assay. Stability constants of copper complexes were measured potentiometrically using SCOGS2 program. In the presence of 10 g/l albumin, all the copper complexes lost their SOD mimetic activities. Multiple regression analysis was employed for the statistical comparisons between the SOD mimetic activity and their physicochemical properties. Correlation exists for the SOD mimetic activity and steric parameter $(E_s)$ and/or electronic parameter $({\Sigma}{\sigma})$ in xanthine/xanthine oxidase (XOD) system, demonstrating that E, plays a key role in SOD activity whereas ${\Sigma}{\sigma}$ influences it to a lesser extent. The protective effect of copper complexes against membrane damage was measured by counting D-glucose released frm $EG_s$. D-glucose and XOD were entrapped within $EG_s$ and acetaldehyde was used as a substrate for XOD. In this membrane model system using $EG_s$, hydrophobic parameter $({\Sigma}{\pi})$ is of most importance, producing parabolic equation while $E_s$, and ${\Sigma}{\sigma}$ appear to playa minor role in protection against D-glucose release. In summary, to design an efficient SOD mimetic, stability, steric factor, lipophilicity and redox potential should be considered.

• Tuberculosis and Respiratory Diseases
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• 제41권1호
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• pp.11-19
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• 1994

연구배경 : 결핵균은 facultative intracellular pathogen으로 대식세포에서 생존 번식할 수 있으며, 결핵균이 체내에서 제거되려면 대식세포와 T 임파구에 의한 효과적인 세포매개성 면역반응이 필요하다. 폐포대식세포에 의한 결핵균 살균은 크게 산소의존성 과정과 산소비의존성 과정으로 구분되는데 산소의존성과정은 NADPH oxidase에 의해 산소가 환원반응으로 과산화음이온을 생성하는 과정으로 시작된다. 저자들은 폐결핵환자의 경우 폐포대식세포의 산소유리기 생성의 이상으로 결핵균이 세포내 오래 생존 번식할 것으로 추정하여 폐결핵환자와 대조군에서 폐포대식세포와 말초혈액 단구세포를 분리하여 분비되는 과산화음이온의 양을 비교하여 보았다. 방법 : 대조군과 폐결핵환자에서 폐포대식세포와 말초혈액내 단구세포를 분리하여 기저상태 및 PMA로 자극한 후 분비되는 과산화음이온의 양을 ferricytochrome-C를 환원시켜 나타나는 발색반응을 이용하여 측정하였고, 단구세포의 경우 결핵환자의 혈청에 의해 어떤 변화를 보이는지 관찰하였다. 결과 : 1) 폐포대식세포에서 분비하는 과산화음이온은 폐결핵환자군와 대조군 사이에 차이가 없었고, PMA로 자극을 했을 때도 두군 사이에 차이가 없이 모두 유의한 증가를 보였다. 2) 말초혈액 단구세포에서 분비하는 과산화음이온은 폐결핵환자군과 대조군 사이에 차이가 없었지만, PMA로 자극을 했을 때 두군에서 모두 유의한 증가를 보였고 폐결핵환자군이 대조군에 비해 높았다. 한편 결핵환자 혈청으로 폐결핵환자군과 대조군의 말초혈액 단구세포를 자극했을 때도 두군에서 모두 유의하게 증가되었다. 결론 : 폐포대식세포와 말초혈액 단구세포에서 분비하는 과산화음이온의 양은 정상인과 폐결핵환자에서 차이가 없었다. 따라서 폐포대식세포에서의 과산화음이온 분비가 부족하여 결핵균이 폐포대식세포내에서 장기간 생존하는 것으로 생각되지 않으며, 오히려 결핵환자의 혈청내에는 말초혈액 단핵구의 과산화음이온 분비를 자극하는 물질이 있을 것으로 생각되나, 정상인 혈청이 과산화음이온 생성에 미치는 효과에 대한 비교 연구가 필요할 것으로 사료된다.

• Tuberculosis and Respiratory Diseases
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• 제39권6호
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• pp.526-535
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• 1992

연구배경 : 산소반응성 대사물에 의한 결핵균 살해능은 대식세포의 활성화 상태에 의해 좌우되는데 체외에서의 이러한 효과를 priming 이라 한다. priming 효과를 유도하는 물질에는 IFN-$\gamma$와 LPS가 대표적인 물질인데 이들 자체가 superoxide와 같은 산소반응성 물질의 생성을 증가시키지는 않지만 식균작용이나 PMA와 같은 화학적 물질에 반응하여 증강된 산소반응성 물질의 생성을 유도한다. 혈액단구세포와는 달리 폐포대식세포는 일상적인 외부환경에 노출되어 있기 때운에 priming 효과에 대한 논란이 있고 결핵균 세포벽의 각 성분이 대식세포의 활성화에 상반되는 결과를 보인다는 보고들이 있어 본 연구에서는 사람의 폐포대식세포와 혈액단구세포, 그리고 백서의 폐포대식세포에서 IFN-$\gamma$에 의한 priming 효과를 비교 관찰하였고 결핵균증 H37Ra 균증이 폐포대식세포에 노출되었을 때 나타나는 superoxide의 생성능의 변화를 비교하여 보았다. 방법 : 사람과 백서에서 얻은 기관지폐포세척액을 Petri dish에 부착시키고 cold shock 방법으로 부착된 대식세포를 분리하여 24시간 IFN-$\gamma$로 전처치한 후의 priming 효과와 H37Ra 결핵균종을 노출시켰을 시의 superoxide의 생성능을 ferricytochrome reduction 방법으로 측정하여 비교하였다. 결과 : 1) 사람 폐포대식세포에서는 고농도의 IFN-$\gamma$ 전처치로도 priming 효과가 관찰되지 않은 반면 혈액단구세포와 백서 폐포대식세포에서는 priming 효과를 관찰할 수 있었다. 2) 폐포대식세포를 비독력 결핵균종인 H37Ra 생균에 노출시킨 결과 사람과 백서 공히 triggering 효과를 나타내었고 그 분해물에 의한 노출 역시 유사한 결과를 나타내었다. 결론 : 사람의 폐포대식세포는 다른 대식세포와는 달리 일상적인 외부환경에 노출되어 있으으로 priming 효과가 관찰되지 않았으며 비독력 결핵균종인 H37Ra에 의해서는 폐포대식세포의 활성화를 억제하는 효과를 관찰할 수 없었다.