Ca2+ Adenosine Triphsphatase on the Outer Surface of Chicken Erythrocytes

김형로,지은정 생화학분자생물학회 1984 BMB Reports Vol.10 No.4

Ca^(2+)-dependent adenosine triphosphatase in intact chicken erythrocytes was markedly activated by Ca^(2+) and Mg^(2+) but was found to be unrelated to the Na^+-K^+-ATPase, showing relatively broad substrate specificity upon ATP, CTP, and GTP with almost equal rates. Treatment with trypsin, lipase and phospholipase C on the intact erythrocytes decreased the enzyme activity, suggesting that the enzyme is an ecto-enzyme composed of phospholipid-protein complex.

Mg2+ Dependency of Adenosine Diphosphate Ribose Pyrophosphohydrolase in Rabbit Liver

김형로,지은정,김유현 생화학분자생물학회 1984 BMB Reports Vol.10 No.4

Previously, we reported that there were two kinds of organ specific ADPRase isoenzymes in rabbit tissues on the basis of their Mg^(2+) dependence. The present work is concerned with investigating the subcellular localization and properties of the liver ADPRase. ADPRase present in nuclei and mitochondria did not require Mg^(2+) for their activity, while cytoplasmic ADPRase showed absolute Mg^(2+) requirement but might be converted to Mg^(2+) independent form on storage at 4℃. These results suggest that newly synthesized cytoplasmic Mg^(2+)-dependent ADPRase be transferred and converted to nuclear and mitochondrial Mg^(2+)-independent ADPRase.

Alcohol Dehydrogease in Rat Stomach

김형로,지은정,이무삼 생화학분자생물학회 1984 BMB Reports Vol.10 No.4

The rat stomach alcohol dehydrogenase was partially purified and characterized on substrate specificity and kinetic properties. The K_m and V_(max) of the alcohol dehydrogenase were much higher than those of the liver enzyme. These properties strongly suggest that the stomach of the rat actively participates in the alcohol metabolism only in high concentrations, comparable to the serum alcohcl level of man after heavy ingestion of alcoholic beverage, while the metabolism of alcohol in man has been reported to be confined only in the liver.

알코홀 대사에 미치는 Nicotinamide의 영향

金炯魯,池垠政,金禹現 전북대학교 의과학연구소 1980 全北醫大論文集 Vol.4 No.2

家兎赤血球의 Adenosine Diphosphate Ribose Pyrophosphohydrolase에 관한 연구

金炯魯,池垠政,金禹現 전북대학교 의과학연구소 1981 全北醫大論文集 Vol.5 No.2

Mg^2+ -dependent adenosine diphosphate ribose pyrophosphohydrolase(Mg^2+ -dependent ADPRase) from rabbit erythrocytes, which catalyzes the hydrolysis of adenosine diphosphate ribose(ADP-ribose) to AMP and ribose-5'-phosphate in the presence of divalent metal ions such as Mg^2+ or Mn^2+ was purified and its properties were characterized. 1. Mg^2+ -dependent ADPRase was partially purified 1331-fold to have the specific activity of 77.2μmoles per mg protein·Pr by ammonium sulfate fractionatior, DEAE-cellulose chromatography and Sephadex gel filtration. 2. The molecular weight of the enzyme was approximately 74,000 dalton determined by gel filtration on Sephadex G-100. 3. The enzyme showed a great substrate-specificity to ADP-ribose, while it did not hydrolyze the pyrophosphate bond of NAD, NADH, ADP, ATP and inorganic pyrophosphate, and phosphodiester bond of nitrophenyl-pT, indication that its true substrate in vivo is ADP-ribose. 4. The enzyme which has optimal pH of 9.5 was most stable at pH 6.2 in the pH range of the 5.4 to 8.6 with some loss of its activity during 2 hour incubation at 37˚.

Ornithine Aminotransferase의 活性 測定法 考案

金炯魯,李桂貞,朴鎭宇 전북대학교 의과학연구소 1981 全北醫大論文集 Vol.5 No.1

An attempt was made to develop a new assay method for ornithine aminotransferase which catalyzes the transfer of δ-amino group in ornithine to α-ketoglutarate to yield glutamate-γ-semialdehyde and glutamate. Glutamate-γ-semialdehyde (or pyrroline-5'-carboxylic acid), one of the reaction products was found to produce a colored compound showing a peak absorbance at 510nm with ninhydrin in hot acidic solution, whereas ornithine of glutamate didn't produce any colored production indicated that the enzyme activity could be properly assayed by reading the change of absorbance at 510nm. The enzyme activity measured by the new assay method was widely distributed in mouse tissues, especially high in cytoplasmic fraction of small intestine and kidney, and in mitochondrial fraction of liver. The enzyme activity showed increasing tendency in liver and kidney with age in contrast to decreasing tendency in small intestine.

Mg^2+-依存型 Adencsine Diphosphoribose Pyrophosphohydrolase의 非依存型으로의 轉換機轉에 관한 硏究

金炯魯,池垠政,朴鎭宇 전북대학교 의과학연구소 1982 全北醫大論文集 Vol.6 No.2

Mg^2+-dependent adenosine diphosphoribose pyrophoshohydrolase(Mg^2+ -dependent ADPRase) which catalyzes the hydrolysis of adenosine diphosphoribose(ADP-ribose) to AMP and ribose-5'-phosphate in the presence of Mg^2+ was mainly localized in cytosol fractions to the contrary with the presence of Mg^2+-independent form in nuclear, mitochondrial and microsomal fractions. Mg^2+-dependent ADPRase in hepatic cytosol was converted to Mg^2+ -independent form during the storage of cytosol fraction with the significant increase of total ADPRase owing to the partial activation of Mg^2+ -independent enzyme by Mg^2+. Mg^2+-independent ADPRase converted from Mg^2+ -dependent form was insoluble but completely solubilized with 2% Triton X-100. The molecular weights of Mg^2+ -independent and Triton-solubilized Mg^2+ -independent ADPRases determined by gel filtration on Sephadex G-150 were approximately 74,000 and over 400,000 respectively, indicating that Mg^2+ -independent ADPRase is the polymerized form of Mg^2+ -dependent form. The polymerized Mg^2+ -independent ADPRase was reconverted to original Mg^2+ -dependent form by the treatment of 101M mercaptoethanol, suggesting that conversion is resulted from the polymerization of Mg^2+ -dependent form by the oxidation of sulfhydryl groups to disulfide bonds.

人體胎盤의 Adenosine Diphosphate Ribose Pyrophosphohydrolase에 關한 硏究

金炯魯,池垠政,金禹現 전북대학교 의과학연구소 1978 全北醫大論文集 Vol.2 No.-

Metabolism of Phosphoadenosine Diphosphate Ribose in Chickern Serum

김형로,지은정 생화학분자생물학회 1983 BMB Reports Vol.9 No.4

Phosphoadenosine diphosphate ribose(p-ADPR) produced from NADP by the hydrolytic cleavage of- membrane-bound NADPase is a specific inhibitor of NADP dehydrogenase but its metabolic fate has not bees clarified. Contrarx to our previous suggestion of the presence of phosphoadenosine diphosphate ribose phophosphohydrolase(p-ADPRase) p-ADPR seems to be metabolized to AMP and ribose-5phosphate(R-5-P) via ADPR by the combined action of alkaline phosphatase and ADPRase evidenced by the following results. 1. p-ADPRase can not be separated from ADPRase, a hydrolytic enzyme of ADPR to AMP and R-5-P, throughout the enzyme purification steps. 2. Hydrolytic cleavage of p-ADPR is strongly reduced in the presence of inorganic phosphate, an inhibitor of phosphatase, while that of ADPR is not affected. 3. Enzymatic production of inorganic phosphate from p-ADPR is greater than that of R-5-P. 4. Chromatographic results show that ADPR, AMP and R-5-P are produced from p-ADPR.

Lanthanum Chloride의 抗糖尿 效果

金炯魯,盧惠援,朴鎭宇 전북대학교 의과학연구소 1984 全北醫大論文集 Vol.8 No.2

Since Ca^2+ plays many important roles in cellular metabolism, an attempt was made to investigate the effect of lanthanum, a Ca^2+-antagonist, on alloxan- or streptozotocin-induced diabetes mellitus. Alloxan(80mg/kg bcdy weight) induced permanent hyperglycemia in rats reaching the blood glucose level of 585mg% at 48 hours and about two-tbird of rate was died for 5-day period after alloxan treatment. Lanthanum chloride(100mg/kg body weight) administration 1 hour before alloxan comepletely prevented alloxan-induced hyperglycemia, while it had no effect on streptozotocin-induced hyperglycemia, suggesting that lanthanumacts on a certain step between alloxan uptake into B-cell and the formation of free radicals plausible causative factor of alloxan-diabetogenesis. Lanthanum treatment at 24 hours after alloxan administration partially prevented alloxan-induced hyperglycemia, indicating that lanthanum stimulates the recovering process of B-cell damaged by alloxan.