Biochemistry of NO Synthesis

권년수 한국지질학회 1999 韓國脂質學會誌 Vol.9 No.1

Nitric Oxide; Biochemistry of NO Synthesis

권년수 한국지질동맥경화학회 1999 韓國脂質學會誌 Vol.9 No.1

거식세포 Nitric Oxide 생성의 생화학

권년수 중앙대학교 의과대학 의과학연구소 1991 中央醫大誌 Vol.16 No.1

Synthesis of nitric oxide is a recently discovered property of macrophages, endothelial cells, neutrophils, hepatocytes, and cells in adrenal gland and cerebellum. In all cell types, L-arginine is utilized to produce nitric oxide, leaving L-citrulline. Nitric oxide mediates some of cytotoxic actions of macrophages. Endothelium-derived nitric oxide is a major relaxant of vascular smooth muscle. In macrophages, nitric oxide synthase activity is induced by immunologic stimuli. The activity is cytosolic, exhibits a strict requirement for NADPH. Nitric oxide synthase requires tetrahydrobioptein as a cofactor, and reductases for reduced biopterins(e.g., dihydropteridine reductase) are necessary for continuous recycling of the cofactor. FAD and a reduced thiol such as glutathione are necessary for maximal nitric oxide generation by nitric oxide synthase. Stable isotope studies have shown that nitric oxide derives form one of the two equivalent guanidino nitrogens of L-arginine, and the dioxygen is the source of the oxygens incorporated into L-citrulline and nitric oxide. Nitric oxide syntheses is initiated by generation N^ω-hydroxy-L-arginine as an intermediate through an NADPHdependent hydroxylation of L-arginine. Nitric oxide synthase exclusively utilized the hydroxylated guanidino nitrogen for nitric oxide synthesis. Further reaction of N^ω-hydroxy-L-arginine to form nitric oxide and L-citrulline requires oxidations of NADPH and tetrahydrobiopterin.

Inhibition of Tumor Cell Ribonucleotide Reductase by Macrophage - derived Nitric Oxide

권년수 한국생화학분자생물학회 (구 한국생화학회) 1991 추계학술대회집 Vol.- No.-

Electroconvulsive Shock 이 마우스 뇌조직 Superoxide Dismutase 의 활성에 미치는 영향

권년수,이희성 ( Nyoun Soo Kwon,Hi Sung Lee ) 생화학분자생물학회 1984 BMB Reports Vol.17 No.3

In the present study, prolonged effects of the serial electroconvulsive shocks on the activity of superoxide dismutase (superoxide: superoxide oxidoreductase, EC 1.15.1.1) : both cyanide-sensitive cytosolic enzyme and cyanide-resistant mitochondria) enzyme, were observed in the mouse brain. The rate constants for synthesis and degradation of these enzymes were determined. In addition, the changes in the superoxide radical production, the amount of hydrogen peroxide and the activity of superoxide dismutase were observed in the mouse brain which received single electroconvulsive shock. The results were summarized as follows: 1. Homogenates prepared from the brains of mice treated with single electroconvulsive shock showed considerably higher superoxide radical production when compared with those of the control mice. 2. By single electroconvulsive shock the generation of hydrogen peroxide increased at 1 minute after the electric stimulus; while the activity of superoxide dismutase increased at the time when tonic convulsion occurred. 3. By the serial electroconvulsive shocks the activity of cytosolic superoxide dismutase increased to approximately 1.6 times its control value (Kd=3.60×10^(-2)/hr; Ks=6.01 units/hr/g tissue ; t_½=19 hrs) ; and the mitochondriaI enzyme increased to approximately 2 times its control value (Kd=1.53×10^(-2)/hr; Ks=I.44 units/hr/g tissue; t_½=45 hrs). 4. The rate constants at recovery period were: Kd=1.91×10^(-2)/hr;Ks=2.01 units/hr/g tissue; t_½=36 hrs for the cytosolic superoxide dismutase and Kd =3.08×10^(-2)/hr; Ks=1.42 units/hr/g tissue; t_½=23 hrs for the mit ochondrial enzyme.

Electroconvulsive Shock이 마우스 뇌조직 Superoxide Dismutase의 활성에 미치는 영향

권년수,이희성,Kwon, Nyoun-Soo,Lee, Hi-Sung 생화학분자생물학회 1984 한국생화학회지 Vol.17 No.3

In the present study, prolonged effects of the serial electroconvulsive shocks on the activity of superoxide dismutase (superoxide: superoxide oxidoreductase, EC 1.15.1.1): both cyanide-sensitive cytosolic enzyme and cyanide-resistant mitochondrial enzyme, were observed in the mouse brain. The rate constants for synthesis and degradation of these enzymes were determined. In addition, the changes in the superoxide radical production, the amount of hydrogen peroxide and the activity of superoxide dismutase were observed in the mouse brain which received single electroconvulsive shock. The results were summarized as follows: 1. Homogenates prepared from the brains of mice treated with single electroconvulsive shock showed considerably higher superoxide radical production when compared with those of the control mice. 2. By single electroconvulsive shock the generation of hydrogen peroxide increased at 1 minute after the electric stimulus; while the activity of superoxide dismutase increased at the time when tonic convulsion occurred. 3. By the serial electroconvulsive shocks the activity of cytosolic superoxide dismutase increased to approximately 1.6 times its control value ($Kd=3.60{\times}10^{-2}/hr$; Ks=6.01 units/hr/g tissue; $t_{1/2}=19\;hrs$); and the mitochondrial enzyme increased to approximately 2 times its control value ($Kd=1.53{\times}10^{-2}/hr$; Ks=1.44 units/hr/g tissue; $t_{1/2}=45\;hrs$). 4. The rate constants at recovery period were: $Kd=1.91{\times}10^{-2}/hr$; Ks=2.01 units/hr/g tissue; $t_{1/2}=36\;hrs$ for the cytosolic superoxide dismutase and $Kd=3.08{\times}10^{-2}/hr$; Ks=1.42 units/hr/g tissue; $t_{1/2}=23\;hrs$ for the mit ochondrial enzyme. ICR순계 마우스에 electroconvulsive shock(ECS)을 가해 뇌조직에서 superoxide radical의 생성, $H_2O_2$의 양, superoxid edismutase(superoxide: superoxide oxidoreductase, EC 1.15.1.1)의 활성에 미치는 영향 등을 관찰하고, 주기적으로 반복하여 ECS를 가함으로써 superoxide dismutase(SOD)를 유발시켜 합성 및 분해속도상수를 구한 결과 다음과 같은 결론을 얻었다. 1. ECS를 받은 마우스의 뇌조직 균질액에서 superoxide radical의 생성이 대조군에 비해 유의한 차이가 있게 증가되었다(p<0.01). 2. ECS에 의해 마우스 뇌조직의 SOD 활성도는 긴장성 경련기에, $H_2O_2$의 양은 1분후에 가장 높은 증가를 나타내었으며 SOD 활성도와 $H_2O_2$양의 변화 양상은 비슷하였다. 3. 일련의 ECS로 세포질 SOD는 대조군의 약 1.6배로 전기자극 후 11일에 가장 높은 활성을 나타냈다($Kd=3.60{\times}10^{-2}/hr$; Ks=6.01 units/hr/g tissue; $t_{1/2}=19\;hrs$). Mitochondria의 SOD는 전기자극후 11일에 대조군의 약 2배로 가장 높은 활성을 나타내었다($Kd=1.53{\times}10^{-2}/hr$; Ks=1.44 units/hr/g tissue; $t_{1/2}=45\;hrs$). 4. 회복기에 세포질 효소의 속도상수는 Kd가 $1.91{\times}10^{-2}/hr$, Ks가 2.01 units/hr/g tissue, 반감기는 36시간이었으며, mitochondria 효소의 Kd는 $3.08{\times}10^{-2}/hr$, Ks는 1.42 units/hr/g tissue, 반감기는 23시간이었다.

거식세포 Nitric Oxide 생셩의 생화학

권년수 중앙대학교 의과대학 의과학연구소 1991 中央醫大誌 Vol.16 No.특집호

Colloguia : Nitic Oxide Produced from S - Nitroso - N - acetyl - D , L - penicillamine Inhibits Bacterial Growth

권년수,이철규,이희성 한국생화학분자생물학회 (구 한국생화학회) 1992 추계학술대회집 Vol.- No.-

마우스 장기에서의 Superoxide Dismutase의 분포

이증연,권년수,이희성 중앙대학교 의과대학 의과학연구소 1983 中央醫大誌 Vol.8 No.1

The subcelluar localization of superoxide dismutase(EC 1.15.1.1) was investigated in various organs of mouse. Mouse organs were fractionated into mitochondrial and cytosolic fractions by differential centrifugation. The activity of superoxide dismutase was measured by the method of McCord and Fridovich. The results were summarized as follows ; 1. Mouse organs contain two types of superoxide dismutase, one of which is localized in the mitochondria and the other was found in the cytosol. 2. Superoxide dismutase activity was found in all mouse organs investigated. Maximal activity of enzyme was observed in testicle, kidney and adrenal gland. 3. Most of superoxide dismutase activity was present in the cytosolic fraction(88~95%) , the rest being associated with mitochondria. 4. The cytosolic superoxide dismutase was found that contains copper and zinc and similar to the other cupro-zinc superoxide dismutase which was have been isolated from diverse eukaryotes. In contrast, the mitochondrial superoxide dismutase contains to be a manganoprotein. 5. The activity of cytosolic superoxide dismutase of testicle was most prominent in testicle than those of other tissues. And however, that of mitochondrial superoxide dismutase was highest in the adrenal gland. 6. The specific activity of superoxide dismutase in mitochondria was found about 5 fold greater than that of superoxide dismutase in cytosol. 7. 5mM cyanide inhibit the activity of cytosolic superoxide dismutase to 50~75%, but mitochondrial superoxide dismutase was inhibited to 9%.

사람 태반의 Superoxide Dismutase의 정제 및 성상

문진수,권년수,이근배,이희성 중앙대학교 의과대학 의과학연구소 1982 中央醫大誌 Vol.7 No.2

The distribution and some properties of superoxide dismutase of human term placenta have been studied. Human placenta was fractionated by differential centrifugation into mitochondrial and cytosolic fractions. The activity of superoxide dismutase was measures by the methodof McCord and Fridovich. Cytosolic superoxide dismutase was purified by ammonium sulfate precipitation, treatment with a chloroform-ethanol mixture, and DEAE-cellulose column chromatography. The results are summarized as follows; 1. Human term placenta contains two types of superoxide dismutase, one of which is localized in the mitochondria while the other is found in the cytosol. The mitochondrial superoxide dismutase was inactivated by treatment with a moxture of chloroform and ethanol whereas the cytosolic superoxide dismutase was not. 2. The activity of cytosolic and mitochondrial superoxide dismutase was found to be 7.44 units and 1.27 units per g of wet tissue, repectively. 3. The molecular weight of cytosolic superoxide dismutase was estimated to be about 33,000 by gel filtration. 4. The ultraviolet absorption spectrum of cytosolic enzyme indicates the lack of tryptophan. The spectrum of the enzyme in the uitraviolet region was similar to that of phenylalanine. 5. Purified cytosolic superoxide dismutase contains 2Cu^2+ and 2Zn^2+ per molecule. This enzyme was found to be similar to the other cupro-zinc superoxide dismutase which have been isolated from diverse eukaryotes. 6. Cyanide at 0.5 mM and 5.0 mM inhibits the activity of cytosolic superoxide dismutase 31% and 98%, respectively, but mitochondrial superoxide dismutase was not inhibited by this compound.