• The Korean Journal of Physiology and Pharmacology
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• 제13권1호
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• pp.15-22
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• 2009

This study was undertaken to elucidate the underlying mechanisms of ATP depletion-induced membrane transport dysfunction and cell death in renal proximal tubular cells. ATP depletion was induced by incubating cells with 2.5 mM potassium cyanide(KCN)/0.1 mM iodoacetic acid(IAA), and membrane transport function and cell viability were evaluated by measuring $Na^+$-dependent phosphate uptake and trypan blue exclusion, respectively. ATP depletion resulted in a decrease in $Na^+$-dependent phosphate uptake and cell viability in a time-dependent manner. ATP depletion inhibited $Na^+$-dependent phosphate uptake in cells, when treated with 2 mM ouabain, a $Na^+$ pump-specific inhibitor, suggesting that ATP depletion impairs membrane transport functional integrity. Alterations in $Na^+$-dependent phosphate uptake and cell viability induced by ATP depletion were prevented by the hydrogen peroxide scavenger such as catalase and the hydroxyl radical scavengers(dimethylthiourea and thiourea), and amino acids(glycine and alanine). ATP depletion caused arachidonic acid release and increased mRNA levels of cytosolic phospholipase $A_2(cPLA_2)$. The ATP depletion-dependent arachidonic acid release was inhibited by $cPLA_2$ specific inhibitor $AACOCF_3$. ATP depletion-induced alterations in $Na^+$-dependent phosphate uptake and cell viability were prevented by $AACOCF_3$. Inhibition of $Na^+$-dependent phosphate uptake by ATP depletion was prevented by antipain and leupetin, serine/cysteine protease inhibitors, whereas ATP depletion-induced cell death was not altered by these agents. These results indicate that ATP depletion-induced alterations in membrane transport function and cell viability are due to reactive oxygen species generation and $cPLA_2$ activation in renal proximal tubular cells. In addition, the present data suggest that serine/cysteine proteases play an important role in membrane transport dysfunction, but not cell death, induced by ATP depletion.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2003년도 Challenges and Achievements in Environmental Health
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• pp.177-180
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• 2003

A glassy carbon electrode(GCE) modified with nafion-DTPA-glycerol was used for the highly selective and sensitive determination of a trace amount of Cu$\^$2+/. Various experimental parameters, which influenced the response of nafion-DTPA-glycerol modified electrode to Cu$\^$2+/, were optimized. The copper(II) was accumulated on the electrode surface by the formation of the complex in an open circuit, and the resulting surface was characterized by medium exchange, electrochemical reduction, and differential pulse voltammetry, A linear range was obtained in the concentration range 1.0${\times}$10$\^$-8/M∼1.0${\times}$10$\^$-6/M Cu(II) with 7 min preconcentration. Further, when an approximate amount of lead(II) is added to the test solution, nafion-DTPA-glycerol modified glassy carbon electrode has a dynamic range of 2 orders magnitude(1.0${\times}$10$\^$-9/M∼1.0${\times}$10$\^$-7/M). The detection limit(3 $\sigma$) was as low as 5.0${\times}$10$\^$-6/M(0.032ppb). The interferences from other metal ions could be reduced by adding KCN into the sample solutions. This method was applied to the determination of coppe,(II) in certified reference material(3.23${\times}$10$\^$-7/M, 21ppb), sea water(9.50${\times}$10/sup-7/M, 60ppb). The result agrees satisfactorily with the value measured by Korea Research Institute of Standard and Science.

• 동의생리병리학회지
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• 제17권3호
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• pp.728-737
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• 2003

This study was investigated to prove the effect of GMGHT on the gultamate receptor, free radical and brain damage in rats sujected to Brain Ischemia The results were as follows; 1, GMGHT showed significant inhibitory effect of GMGHT on LDH release induced by NMDA, AMPA, and kinate. 2. GMGHT showed significant inhibitory effect of GMGHT on LDH release induced by BSO and Fe/sup 2+/. 3. GMGHT decreased coma duration time in a infatal dose of KCN and showed 30% of survival rate in a fatal dose. 4. GMGHT decreased ischemic area and edema incited by the MCA blood flow block. 5. GMGHT showed improvement of forelimb and hindlimb test after MCA occulusion in neurological exemination. 6. GMGHT showed no significant change after MCA occulusion in pathological observation as normal group. These results indicate that GMGHT can be used in the brain damage sujected to Brain Ischemia. Further study will be needed about the functional mechanism and etc.

• 대한한의학회지
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• 제25권3호
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• pp.32-44
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• 2004

Objectives : This study was undertaken to prove the effect of GSHT on the glutamate receptor, free radical and brain damage in rats subjected to brain ischemia Methods : Levels of cultured cortical neuron death caused by toxic chemicals were measured by LDH release assay. Neuroprotective effects of GSHT on brain tissues were examined in vivo by ischemic model of middle cerebral artery (MCA) occlusion. Results : GSHT showed significant inhibitory effect on LDH release induced by NMDA-kinate-Fe/sup 2+/. GSHT remarkably decreased coma duration time in a nonfatal dose of KCN and showed higher survival rate in a fatal dose. GSHT remarkably decreased ischemic area and edema induced by the MCA blood flow block. GSHT showed high improvement of forelimb and hind limb test after MCA occlusion in neurological examination. GSHT showed no significant change after MCA occlusion in pathological observation of the normal group. Conclusions : These results indicate that GSHT can be used to treat the brain damage caused by brain ischemia. Further study will be needed about the functional mechanism, etc.

• Applied Biological Chemistry
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• 제24권3호
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• pp.167-173
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• 1981

마늘의 갈변현상중(褐變現象中) 효소적(酵素的) 갈변(褐變)에 관여(關與)하는 polyphenol oxidase 조효소액(粗酵素液)을 추출(抽出)하여 그 성질(性質)을 몇가지 조사(調査)하였다. 기질(基質)로서는 여러 phenol화합물(化合物)들을 사용(使用)해 본 결과(結果), diphenol류(類)와 monophenol류(類)는 거의 갈변(褐變)되지 않았으나 triphenol인 pyrogallol, gallic acid는 크게 갈변(褐變)되는 것으로 보아 마늘의 polyphenol oxidase는 triphenol oxidase로 보인다. 이 효소의 최적(最適) pH는 6.5 부근으로 약산성측(弱酸性側)에 있었으며 열안정성(熱安定性)은 $80^{\circ}C$, 5분(分) 가열(加熱)로 90%의 잔존율(殘存率)을 보여 열(熱)에 매우 안정(安定)하였다. Na-metabisulfite는 1mM의 농도(濃度)에서 안전(完全)한 조해(阻害)를 하였고, potassium cyanide, L-ascorbic acid, thiourea순(順)으로 효소활성(酵素活性)을 조해(阻害)하였다. $Mg^{2+}$는 효소활성(酵素活性)을 증가(增加)시켰고 $Cu^{2+}$는 저농도(低濃度)(1mM)에서는 polyphenol oxidase가 활성화(活性化)하는데 비(比)해 고농도(高濃度)(10mM)에서는 조해작용(阻害作用)을 하였다. 마늘의 polyphenol oxidase의 Km치(値)는 0.4mM이었다.

• 한국동물학회지
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• 제4권1호
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• pp.7-12
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• 1961

1) Respiratory metabolism patterns and its enzyme systems in the gill tissue of the fresh water mussels, Cristaria plicata were investigated through the examination on the effects of respiratory enzyme inhibitors, (KCN, NAF) and succinoxidase assay, while studying the effects of neutral salts (NaCL, KCL, CaCl2) and pH on oxygen consumption of the gill tissue. 2) In the limited concentration of KCL (0.3mM) and NaCl (0.4mM) solutions, oxygen consumption of the intact gill tissue was accelerated, but in CaCl2(0.5mM) solution, it showed no significant effect. The oxygen consumption was gradually decreased at the above concentrations of these limitations. The optimum pH for the respiration of the gill was 7.3. 3)Cyanide in 10-8M solution inhibited 88.8% of the respiration of the intact gill tissue. Methylene blue accelerated the respiration of the noral gill tissue, and slightly but significantly reversed the cyaniide poisoned respiration. 4)Oxygen consumption of the gill homogenate was apparently increased by the mixed addition of succinate, cytochrome c and activators (AlCl3 and CaCl2). This results suggested that succinoxidase system acts on the respiratory pattern of the gil tissue. 5) It was able to recognize that the enolase, which acts on the anaerobic glycolytic system, participated in the tissue respiration of the gill for NaF in 5$\times$10-2 M solution inhibited 55.5% of the respiration of the same intact tissue.

• Journal of Microbiology
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• 제45권4호
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• pp.333-338
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• 2007

Intracellular NADH:quinone reductase involved in degradation of aromatic compounds including lignin was purified and characterized from white rot fungus Trametes versicolor. The activity of quinone reductase was maximal after 3 days of incubation in fungal culture, and the enzyme was purified to homogeneity using ion-exchange, hydrophobic interaction, and gel filtration chromatographies. The purified enzyme has a molecular mass of 41kDa as determined by SDS-PAGE, and exhibits a broad temperature optimum between $20-40^{\circ}C$, with a pH optimum of 6.0. The enzyme preferred FAD as a cofactor and NADH rather than NADPH as an electron donor. Among quinone compounds tested as substrate, menadione showed the highest enzyme activity followed by 1,4-benzoquinone. The enzyme activity was inhibited by $CuSO_4,\;HgCl_2,\;MgSO_4,\;MnSO_4,\;AgNO_3$, dicumarol, KCN, $NaN_3$, and EDTA. Its $K_m\;and\;V_{max}$ with NADH as an electron donor were $23{\mu}M\;and\;101mM/mg$ per min, respectively, and showed a high substrate affinity. Purified quinone reductase could reduce 1,4-benzoquinone to hydroquinone, and induction of this enzyme was higher by 1,4-benzoquinone than those of other quinone compounds.

• 한국전기전자재료학회논문지
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• 제26권3호
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• pp.232-239
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• 2013

Thin light-active layers of the $CuInSe_2$ solar cell were prepared on Mo-coated sodalime glass substrates by one-step electrodeposition and post-annealing. The structure, morphology, and composition of $CuInSe_2$ film could be controlled by deposition parameters, such as the composition of metallic precursors, the concentration of complexing agents, and the temperature of post-annealing with elemental selenium. A dense and uniform Cu-poor $CuInSe_2$ film was successfully obtained in a range of parametric variation of electrodeposition with a constant voltage of -0.5 V vs. a Ag/AgCl reference electrode. The post-annealing of the film at high temperature above $500^{\circ}C$ induced crystallization of $CuInSe_2$ with well-developed grains. The KCN-treatment of the annealed $CuInSe_2$ films further induced Cu-poor $CuInSe_2$ films without secondary phases, such as $Cu_2Se$. The structure, morphology, and composition of $CuInSe_2$ films were compared with respect to the conditions of electrodeposition and post-annealing using SEM, XRD, Raman, AES and EDS analysis. And the conditions for preparing device-quality $CuInSe_2$ films by electrodeposition were proposed.

• Journal of Microbiology
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• 제35권3호
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• pp.200-205
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• 1997

Bothl $Ca^{2+}$ and Sr$^{2+}$-containing methanol dehydrogenases (MDH) were purified to homogeneity with yields of 48% and 42%, respectively, from Methylabacillus methanolovorus sp. strain SK5. Most of the biochemical and structural properties were similar to each other. However, some differences were found: (1) although the overall shape of the absorption spectrum of Sr$^{2+}$-MDH was very similar to that of $Ca^{2+}$-MDH, the absorption intensity originating from the cofactor in Sr$^{2+}$. MDH was higher than that in $Ca^{2+}$-MDH. Small blue shift of the maximum was also observed. These are probably due to a difference in redox state of the cofactors in $Ca^{2+}$ and Sr$^{2+}$-MDH; (2) Sr$^{2+}$-MDH was more heat-stable than $Ca^{2+}$-MDH above 56$^{\circ}C$; (3) the V$_{max}$ values for the methanol-dependent activities of Sr$^{2+}$- and $Ca^{2+}$-MDH in the presence of 3 mM KCN were 2.038 and 808 nmol/mg protein/min, respectively. In addition, the $K_{m}$ values of Sr$^{2+}$ and $Ca^{2+}$ MDH for methanol were 12 and 21 $\mu$M, respectively; (4) the endogenous activity of $Ca^{2+}$-MDH was more sensitive than that of Sr$^{2+}$-MDH in the presence of cyanide; (5) Diethyl pyrocarbonate treatment increased the enzyme activities of $Ca^{2+}$- and Sr$^{2+}$-MDH 4.2- and 1.4-folds, respectively. These results indicate that Sr$^{2+}$ stabilizes the structural conformation and enhances the activity of MDH more than $Ca^{2+}$.

• Applied Biological Chemistry
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• 제37권3호
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• pp.182-188
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• 1994

작물의 인산영양진단을 $^{32}P-bioassay$법에 의하는 것과 같은 원리로 K의 영양진단 가능성을 검토하기 위하여 맥주보리(Hordeum distichum)를 K수준을 달리 공급하여 4주간 수경재배한 후 $^{42}K$(half life: 12.36 hr)와 $^{86}Rb$(half life: 18.86 hr)을 추적자로 사용하여 K-bioassay를 실시했던 바 $^{42}K$와 $^{86}Rb$의 흡수능은 모두 K의 공급수준과 지수적인 역상관을 나타내어 K의 영양진단이 가능하다는 사실을 확인했으며, 반감기가 짧아서 실험시간의 제한을 받게 되는 $^{42}K$대신 K의 analog로 Rb을 사용할 수 있음도 알게 되었다. 그리고 3년생 조생온주감귤(Citrus unshiu Marc.)을 K공급수준을 달리해서 4개월간 수경으로 재배한 뒤 $^{86}Rb$의 흡수능을 측정한 결과 K공급수준과 지수적인 역상관을 나타내어 맥주보리와 비슷한 경향을 나타냈다. 따라서 감귤나무의 경우 $^{86}Rb$ 추적자를 이용한 K-bioassay가 가능하다고 생각된다. 또한, K시비수준을 달리하여 7주간 재배된 보리의 Rb흡수능이 토양 중 치환성 가리함량과 고도의 상관을 보인 점은 K-bioassay에 의한 Rb흡수능 값과 치환성가리의 함량과의 관계에서 작물의 생육에 적당한 치환성가리 함량을 산정해 낼 수 있다고 사료된다. 한편, 맥주보리와 감귤뿌리에 의한 $^{42}K$와 $^{86}Rb$의 흡수는 모두 $5{\times}10^{-3}\;M$ KCN에 의해서 크게 저해되었으므로 K와 Rb이 능동적 흡수가 이루어지고 있음을 알 수 있었다. 감귤의 엽중 K함량은 K의 공급수준과 밀접한 상관이 발견되지 않았기 때문에 $^{86}Rb$을 이용한 K-bioassay법은 엽분석보다 더 정확하게 감귤의 생리적인 K요구성을 측정할 수 있다고 생각된다. 그러나 3년생 이상의 감귤나무에 대하여는 포장시험으로 확인되어야 할 것이다.