• The Korean Journal of Mycology
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• v.17 no.4
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• pp.169-176
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• 1989

Mitochondria in Pleurotus ostreatus was purified by stepped sucrose density gradient centrifugation. The activity of mitochondrial ATPase has been investigated during various times of illumination at each wavelength in the range of 400 nm to 700 nm. The mitochondrial ATPase activity was simulated 1,7 fold by 580 nm illumination compared with the broad wavelength group. The mitochondrial ATPase activity according to various times of illumination was stimulated 2.2 fold for 10 seconds at 580 nm compared with the broad wavelength group. The optimum pH and temperature of the mitochondrial ATPase were 7.4 and $60^{\circ}C$, respectively. The activity of this enzyme was stimulated by 5 mmol $Fe^{3+}$, 5 mmol $Mg^{2+}$, 0.1 mmol $Ca^{2+}$ and 5 mmol $Fe^{2+}$ ion, but inhibited by 5 mmol $Na^{+}$ ion.

• BMB Reports
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• v.31 no.1
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• pp.44-47
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• 1998

Asymmetry amongst nucleotide binding sites of Escherichia coli $F_1$-ATPase was examined using $^{19}F$ NMR signal from fluorinated analogs of adenine nucleotides bound to nucleotide binding sites. ADP-$CF_2-{PO_3}^{2-}$ showed no inhibitory effect to $F_1$-ATPase. But ADP-CHF-${PO_3}^{2-}$ (racemic mixture) showed competitive inhibition of $F_1$-ATPase with $K_i$ of $60\;{\mu}m$. ADP-CHF-${PO_3}^{2-}$ shows only negligible binding to $EF_1$ in the absence of $Mg^2+$. With the addition of $Mg^2+$ to the medium, the $^{19}F$ resonance of free ADP-CHF-${PO_3}^{2-}$ disappeared and the new broad resonances appeared. Appearance of more than two new asymmetric resonances following the binding of ADP-CHF-${PO_3}^{2-}$ to $EF_1$ may indicate that at least one of the isomers showed split resonances. This may suggest that the region between ${\alpha}$-and ${\beta}$-phosphate of ADP-CHF-${PO_3}^{2-}$ which is bound to catalytic sites is experiencing a different environment at different sites.

• The Korean Journal of Mycology
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• v.15 no.4
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• pp.217-223
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• 1987

Mitochondria in the L. edodes was purified by linear sucrose density gradient centrifugation. The mitochondrial ATPase activity was investigated by various wavelength illumination for 30 min at dark state. The mitochondrial ATPase activity was stimulated 1.6 fold by 680 nm illumination compared with dark control group. The mitochondrial ATPase activity of different light illumination time at 680 nm was stimulated 2.3 fold at 5 minutes compared with dark control group. Its optimum pH and temperature were found to be 7.5 and $59^{\circ}C$ after illumination for 5 minutes at 680 nm. The mitochondrial ATPase activity was activated by 5 mmol $Fe^{3+}$, 0.1 mmol $Fe^{2+}$, 0.1 mmol $Mg^{2+}$, 0.5 mmol $K^{+}$, and 0.1 mmol $Ca^{2+}$ ion. But, the enzyme was inhibited by 5 mmol $Na^{+}$ ion.

• The Korean Journal of Physiology
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• v.17 no.2
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• pp.161-168
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• 1983

Studies on the effects of vanadate for Na-K-ATPase activity were carried out with rabbit renal cortex. 1) Na-K-ATPase activity was inhibited with the concentrations of vanadate in incubation medium. The vanadate concentration at which activity was inhibited by 50%$(ID_{50})$ was $10^{-6}M$ and Hill coefficient was 1.00. 2) The fractional inhibition by constant concentration of vanadate decreased with increasing enzyme concentration. 3) Increasing $K^+$ and $Na^+$ concentrations in incubation medium diminished the ability to inhibit Na-K-ATPase by vanadate whereas increasing $K^+$ and $Mg^{2+}$ concentrations potentiated the inhibition of Na-K-ATPase by vanadate. 4) Vanadate didn't inhibit Na-K-ATPase at pH 6.6. Increasing pH potentiated the inhibition of Na-K-ATPase activity. 5) Vanadate inhibited Na-K-ATPase activity reversibly in all range of concentrations in dilution experiment. These results show that vanadate inhibits Na-K-ATPase activity with interacting at $KE_2$ state reversibly.

• Environmental Analysis Health and Toxicology
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• v.8 no.1_2
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• pp.37-58
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• 1993

In order to investigate the toxicities of S-bioallethrin (5-biol) and its combination treatment with N-octyl bicycloheptene dicarboximide (MGK-264), the acute and subacute toxicity, and enzyme activity test were performed. $LD_{50}$ levels of S-biol and MGK-264 in rats are 640 mg/kg and 3, 280 mg/kg respectively. However, when rats were treated with the mixture of S-biol and MGK-264 (1 : 5 ratio), the $LD_{50}$ was decreased to 545 mg/kg. In serological analysis, ALT and LDH were increased in animals treated with the mixture. Also glucose level was significantly increased after 5 weeks in animals treated with both S-biol and the mixture. Other biochemical parameters such as cytochrome P-450 and NADPH-cytochrome c reductase in the liver and kidney were shown to be not significantly changed. Levels of total ATPase and $mg^{2+}$ ATPase were significantly decreased in the liver of animals treated with the mixture after 4-5 weeks. In addition, S-biol can alone decrease total ATPase activity. Total ATPase activity was also significantly decreased in the kidney after 5 week treatment with the mixture. Similarily, glucose-6-phosphatase activity was significantly decreased in animals treated with the mixture. When either S-biol or MGK-264 was administered, cholinesterase and carboxyesterase activities were slightly decreased but they were significantly decreased when the mixture was administered.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.6
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• pp.712-718
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• 1992

This experiment was carried out to investigate some physico-chemical properties of myofibrillar proteins isolated from alkaline and acid rigor muscles of rabbit. The degree of fragmentation was about 0.35 at 3 days of postmortem in acid rigor muscle fiber, whereas it was only 0.3 at 7 days of postmortem in alkaline rigormuscle fiber. $Mg^{2+}$-activated ATPase activities of actomyosin were increased to the highest level at 1st day in acid rigor and at 3rd day in alkaline rigor muscle fiber. $Ca^{2+}$-activated ATPase activities of actomyosin were slightly increased at postmortem. $Mg^{2+}$-, and $Ca^{2+}$-activated ATPase activities were higher in alkaline rigor muscle than those in acid rigor muscle at postmortem. Solubility of actomyosin increased with postmortem but no differences were observed in rigor types. SDS-PAGE(sodium dodecyl sulfate polyacrylamide gel electrophoresis) band patterns of myofibrils did not show significant differences between rigor types, but newly 30.000 dalton proteins were appeared at 3 day postmortem in both rigor types.

• The Korean Journal of Zoology
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• v.23 no.2
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• pp.61-68
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• 1980

Quantitative analysis of the activities of transport ATPases as well as alkaline phosphatase of the mouse uterus was carried out during the estrous cycle. Even though the proportional patterns of the enzyme activities were similar each another between the stages of estrous cycle, the absolute activities of the enzymes except $K^+$-dependent and $Na^+$, $K^+$-activated ATPases at the time of estrus were significantly (p<0.025) higher than that at any other time of the estrous cycle. That is, the activities of $K^+$-dependent and $Na^+$, $K^+$-activated ATPases were negligible during the period of time from diestrus to estrus while the little activities (0.04 $\\sim$ 0.05$\\mu$M/mg protein/hr in average, $6\\sim7$% of the total enzyme activity) of these enzymes appeared at the time of metaestrus. On the other hand, at the time of estrus, the activities of $Mg^++$-dependent phosphatase, transport ATPase and alkaline phosphatase were rapidly and tremendously increased to be 0.69 (35%), 0.42 (21%) and 1.58 (79%), respectively. The activity of alkaline phosphatase was in the range of 0.60 $\\sim$ 1.58 (79 $\\sim$ 90%) and predominant throughout the estrous cycle. The activity of $Mg^++$-dependent alkaline phosphatase was estimated as 12 $\\sim$ 16% of the total enzyme activity. Therefore, it is assumed likely that $K^+$-dependent and $Na^+$, $K^+$-activated ATPases are not the main factors to control the fluid accumulation at the time of estrus, but may be the factors to reabsorb the luminal fluid into the uterine epithelium at the time of metaestrus, and that $Mg^++$-dependent phosphatase, transport ATPase and alkaline phosphatase must be closely involved in the secretion of luminal fluid from the epithelial cells of the mouse uterus.

• The Korean Journal of Physiology
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• v.1 no.2
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• pp.141-150
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• 1967

The present investigation was initially undertaken to see if there exists $Na^+-K^+$ activated ATPase in the microsome fraction of the kidney. Having confirmed the presence of such an enzyme, further attempts have been made to characterize its nature and the following conclusions were obtained: (1) The ATPase activity was greatest at the $Na^+$ concentration of 100 mM as well as at $K^+$ concentration of 10 mM. Moreover, the ATPase activity was found to be depressed by $Ca^{++}$ in the presence of $Mg^{++}$. (2) While the ATPase activity was depressed by Ouabain, the magnitude of inhibition was greater in the Na medium than in the K medium. (3) NaCN augmented the ATPase activity whereas NaF and IAA depressed it. On the other hand, DNP had little influence on the ATPase activity. (4) Diamox, vasopressin and aldosterone had no effect while $HgCl_2$ markedly depressed the ATPase activity These findings indicate that the nature of ATPase isolated from the microsome fraction of the rabbit kidney is quite similar to that from other organs such as the heart and the muscle, although there are certain features specific to the type of organs.

• Bulletin of the Korean Chemical Society
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• v.30 no.8
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• pp.1724-1728
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• 2009

Severe acute respiratory syndrome coronavirus (SARS-CoV) helicase separates the double-stranded nucleic acids using the energy from ATP hydrolysis. We have measured ATPase activity of SARS-CoV helicase in the presence of various types of nucleic acids. Steady state ATPase analysis showed that poly(U) has two-times higher turnover number than poly(C) with lower Michaelis constant. When M13 single-stranded DNA is used as substrate, the Michaelis constant was about twenty-times lower than poly(U), whereas turnover numbers were similar. However, stimulation of ATPase activity was not observed in the presence of double-stranded DNA. pH dependent profiles of ATP hydrolysis with the helicase showed that the optimal ATPase activities were in a range of pH 6.2 ~ 6.6. In addition, ATP hydrolysis activity assays performed in the presence of various divalent cations exhibited that $Mg^{2+}$ stimulated the ATPase activity with the highest rate and $Mn^{2+}$ with about 40% rate as compared to the $Mg^{2+}$.

• The Korean Journal of Pharmacology
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• v.8 no.1
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• pp.31-40
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• 1972

The author studied the actions of ouabain and diphenylhydantoin sodium on the ATPase activity in mitochondrial fraction isolated from rabbit heart and compared with that of quinidine. The results obtained are as follows: 1) In studying the $(Na^++K^+)-activated$ ATPase activity, the rabbit heart isolated was immediately frozen for 7-9 days (ageing of preparation) and thereafter the mitochondria1 fraction obtained by differential centrifugation technic was treated with solution A containing 0.15% deoxycholate for 24-48 hours at $-10^{\circ}C$ before using in experiment. These methods increased the activity ratio to 0.87-0.98. 2) The $(Na^++K^+)-activated$ ATPase activity in mitochondrial fraction of rabbit heart was not completely but markedly inhibited by ouabain. This inhibitory action of ouabain was moderately antagonised by $K^+$ concentration at constant Na concentration. 3) Diphenylhydantoin sodium in concentration of $5{\times}10^{-4}{\sim}10^{-3}M$ stimulated markedly not only $Mg^{++}-dependent$ ATPase activity but also $(Na^++K^+)$-activated ATPase activity and in concentration lower than $10^{-6}M$ had little effect. However, this effect of diphenylhydantoin was markedly increased in the presence of $Na^+$ alone rather than $K^+$ alone, but lesser than that effect in the presence of both $Na^+$ and $K^+$, together. The stimulating effect of diphenylhydantoin was specifically antagonized by ouabaion. 4) When the rabbits were intravenously injected with ouabain and diphenylhydantion respectively, $(Na^++K^+)-activated$ ATPase activity of rabbit heart of ouabain-treated group was much decreased and both $(Na^++K^+)-activated$ ATPase and $Mg^{++}-activated$ ATPase activity were moderately increased in diphenylhydantoin-treated rabbit group. 5) The $(Na^++K^+)-activated$ ATPase activity in mitochondrial fraction of rabbit heart was slightly inhibited by quinidine in high concentration of $10^{-4}M$, but nearly little effect was observed below the concentration of $5{\times}10^{-5}M$. 6) It might be possible to conclude that diphenylhydantoin specifically antagonised the action of ouabain on the membrane ATPase, which is different from the action of quinidine.