• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.3
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• pp.349-354
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• 1997

Myotibrillar ATPase activity, thermostability and composition of muscle protein were investigated to elucidate biochemical properties regard with rearing period and sex of olive flounder. Myofibrillar ATPase activity of male olive flounder reared for 6, 12 and 20 months was stronger than that of female one. $Mg^{2+}\;(+Ca^{2+})-ATPase$ activity of both female and male fish decreased with the elapse of rearing period, and the activity of male was higher than that of female far beyond the rearing periods. The high correlationship between the weight gain and myofibrillar ATPase activity was observed. The thor mostability of male myofibrillar protein was higher than that of female. Subunit composition of the myofibrillar and sarcoplasmic protein did not show difference between the both sex of the fish.

• Korean Journal of Environmental Agriculture
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• v.21 no.2
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• pp.102-108
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• 2002

In order to investigate the mechanism of growth inhibition by salt stress, lettuces were grown hydroponically in three different nutrient solutions, normal and 30 mM or 50 mM $KNO_3$-added nutrient solutions, and the electrical conductivities of these solutions were 1.0, 4.5, and 6.5 dS/m, respectively. The activities of plasma and vacuolar $H^+$-ATPases in the root tissue of lettuce were measured by specific inhibitors, 100 ${\mu}M$ vanadate and 50 mM $NO_3^-$, respectively. Microsomal ATPase activity of lettuce grown in the normal nutrient solution was $356\pm1.5$ nmol/min/mg protein. When lettuces were grown in 30 mM and 50 mM $KNO_3$-added nutrient solutions, total activities of microsomal ATPases were increased by 1.6 and 1.9 times, respectively, and the increases were mainly mediated by vacuolar $H^+$-ATPase. These results show that lettuces adapt themselves to salt-stressed condition by increasing the activities of $H^+$-ATPases. Effects of various heavy metal ions were investigated on the microsomal ATPases and various metal ions at 100 $\mu M$ inhibited the activities by 10$\sim$25%. $Cu^{2+}$ showed the highest inhibitory effect on the vacuolar $H^+$-ATPase. These results suggest that lettuce increases the activities of root ATPases, specially that of vacuolar $H^+$-ATPase, in salt-stressed growth conditions and $Cu^{2+}$ could be a useful tool to control the activity of vacuolar $H^+$-ATPase.

• Korean Journal of Environmental Biology
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• v.34 no.2
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• pp.97-106
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• 2016

$Na^+/K^+$-ATPase is a membrane protein and plays a key role in osmotic regulation in living organisms. In the present study, a cDNA sequence encoding the $Na^+/K^+$-ATPase alpha subunit from the monogonont rotifer, Brachionus koreanus was cloned by rapid amplification of cDNA ends technique. To investigate the role of this enzyme in osmotic stress, enzymatic activities of $Na^+/K^+$-ATPase were measured after exposure to different salinities for 48 h. The full-length Bk $Na^+/K^+$-ATPase cDNA was 3069 bp-long, encoding a 1022-amino acid polypeptide. Bk $Na^+/K^+$-ATPase possesses eight membrane spanning regions and five conserved domains. Phylogenetic analysis showed that Bk $Na^+/K^+$-ATPase had high identity with those of other species, and was closely clustered with other Brachionus sp. These findings indicate that this protein was conserved both structurally and functionally. B. koreanus $Na^+/K^+$-ATPase activity was stimulated in both hyposaline (6 psu) and hypersaline (32 psu) conditions, suggesting that this protein may play a role in osmoregulation. This study would provide better understanding of the physiology of B. koreanus and this enzyme may be useful as a molecular marker for evaluation of osmotic stress in aquatic environment.

• Microbiology and Biotechnology Letters
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• v.33 no.3
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• pp.184-188
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• 2005

IgE-dependent histamine-releasing factor (HRF) is found extracellularly to regulate the degranulation process of histamine in mast cells and basophils and known to play a predominant role in the pathogenesis of chronic allergic disease. HRF has been also identified in the intracellular region of the cell. Previously, we reported that HRF interacts with the 3rd cytoplasmic domain of the alpha subunit of Na,K ATPase and inhibits Na,K-ATPase activity. The predicated phosphorylation site in HRF by PKC was mapped to one serine residues (S98) by the computer analysis. In this study, we identified that S98 residue of HRF was phosphorylated using anti-HRFpS98 antibody which specifically recognizes the phosphorylated serine residue of HRF and HRFS98A mutant construct. We also performed $^{86}Rb^{+}-uptake$ assay to understand the role of HRF wild-type and HRFS98A mutants on the regulation of Na,K-ATPase activity. Dephosphorylation of HRF at serine 98 residue recovers slightly the inhibitory function of HRF, suggesting that phosphorylated HRF at serine 98 may not suppress the Na,K-hfpase activity.

• The Korean Journal of Zoology
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• v.14 no.2
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• pp.43-56
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• 1971

The Ca uptake by the fragmented sarcoplasmic reticulum of the rabbit skeletal muscle was measured under various concentrations of K, Mg, Caffeine, procaine and quinine. The ATPase activity of this reticular membrane was measured under the same conditions simultaneously. The saturation of Ca uptake was almost completed within 1 minute. The Ca uptake was inhibited by high concentrations of K (above 50 mM) and Mg (above 1 mM)in the absence of ATP. When ATP is present, however, the Ca uptake did not reflect the concentration of K, while it increased greatly as the concentration of Mg was increased. Caffeine and procaine caused the inhibition of Ca uptake in the presence of ATP, but quinine did not. The ATPase activity of the membrane was little affected by the concentration of K, while it was enhanced in the presence of Mg. Caffeine, procaine and quinine did not influence the ATPase activity.

• Korean Journal of Veterinary Research
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• v.23 no.1
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• pp.9-16
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• 1983

The effects of ethanol on Na-K-ATPase activity were investigated with cat kidney homogenate. The results were summarized as follows: 1. Na-K-ATPase activity was inhibited with dose-dependent manner by ethanol of higher concentration than 1%, and showed an estimated $I_{50}$ (the inhibitor concentration to cause 50% inhibition) of 7.5%. 2. Hydrolysis of ATP was linear with the incubation time in the absence and presence of 8% ethanol, whereas it was different with preincubation time in the presence of 15% ethanol. 3. Inhibition of Na-K-ATPase activity by ethanol was not affected by increased enzyme concentration, and showed the reversibility of the inhibitory pattern. 4. Kinetic studies of cationic-substrate activation of Na-K-ATPase showed that ethanol had both properties of classical competitive inhibition for $Mg^{{+}{+}}$ or $K^+ and non-competitive inhibition for ATP or $Na^+$. 5. Arrhenius plot yield two break point at $21^{\circ}$ and $30^{\circ}C$ in the absence of ethanol, whereas showing only one break point at $18^{\circ}C$ in the presence of 8% ethanol. These results suggested that ethanol inhibited Na-K-ATPase activity reversible through a disturbance of microenvironment of lipids associated with the enzyme.

• The Korean Journal of Pharmacology
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• v.12 no.1
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• pp.7-14
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• 1976

Aconiti tuber butanol fraction shows positive inotropic effect on the isolated atrium of rabbit heart. To investigate the mechanism, the effect on microsomal ATPase activity of rabbit heart is observed. The microsomal fraction which contains the $Na^+$- and $K^+$-activated ATPase in the presence of $Mg^{++}$ is isolated from the left ventricle of rabbit heart. The microsomal ATPase activity is maximally stimulated at $Na^+$ and $K^+$ concentration of 100 mM and 10 mM respectively. Microsomal $Na^+-K^+$-activated ATPase is inhibited by ouabain and Aconiti tuber butanol fraction. Ouabain and Aconiti tuber butanol fraction depress $Na^+$-stimulation on microsomal ATPase activity, and the inhibitory effects are not completely reversed at $Na^+$ concentration of 300 mM. Also, $K^+$-stimulation on microsomal ATPase activity is inhibited by ouabin and Aconiti tuber butanol fraction and the inhibitions are not compeletely reversed at $K^+$ concentration of 30 mM. It is, therefore, suggested that the inhibitory effect of Aconiti tuber butanol fraction on the microsomal ATPase activity may contribute to leading to the positive inotropic effect.

• Korean Journal of Food Science and Technology
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• v.18 no.3
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• pp.181-186
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• 1986

Myosin were prepared from red muscle and white muscle, and their ATPase activities were compared. Ca-ATPase activity of bovine myosin from red muscle was higher than that of myosin from white muscle, while Ca-ATPase activity of chicken myosin from red muscle differed hardly from that of myosin from whitemuscle. Atso EDTA-ATPase activity of bovine red muscle myosin was higher than that of white muscle myosin ,although EDTA-ATPase activity of chicken myosin from red muscle differed hardly from that of white muscle myosin. When myosins were treated with trypsin, bovine myosin from white muscle was hydrolysed moreeasily than red muscle myosin was. Chicken myosin from red muscle , however, was hydrolysed by trypsin more easily than white muscle myosin was.

• Journal of the Korean Society of Food Science and Nutrition
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• v.9 no.1
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• pp.45-50
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• 1980

Myofibrilar Protein from Korean Duck Muscle was extracted and ATPase activities were studied. The results were as follows: 1. Mg-activated ATPase activity of Myofibril from Korean Duck, muscle exhibited a biphasic response, ATPase activity was high at a low ionic strength and low activity was showed at high ionic strength. 2. Effect of EDTA on the Myofibrillar protein ATPase activity was studied, it was investigated that the EDTA inhibition was showed at the concentration of $6.9{\mu}g$ and it above. 3. It showed that the effect of Ca++ on ATPase activity was decreased at the lower than $3{\mu}g$. Inhibition showed at the concentration of $6.9{\mu}g$ and it above. 4. It showed that the effect of Mg++ on ATPase activity was decreased at the lower than $3.6{\mu}g$. Inhibition showed at the concentration of $3.9{\mu}g$ and it above.

• Journal of Korean Society on Water Environment
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• v.18 no.4
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• pp.395-400
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• 2002

Lead is one of the most toxic metal and is detectable in practically all phases of environment and in all biological system. Transport, industrial and domestic waste products are the main sources of this pollutant. Ingested lead is rapidly absorbed and widely distributed throughout the body, causing extensive tissue damage. In this study, we chose the freshwater decapods Maceobrachium nipponnese as a sensitive indicator organism for environmental pollution. In order to investigate the possibility in use of $Na^+/K^+ATPase$ activity as a biomarker of lead pollution, we tested the acute toxicity of lead to Maceobrachium nipponnese. The $LC_{50}(96hr)$ value for lead in Maceobrachium nipponnese was found to be $446{\mu}g/L$ with the 95% confidence limits. The lead exposure group at $LC_{50}$ showed a significant $Na^+/K^+ATPase$ inhibition, depending on the exposure time. Comparision of several concentrations of lead revealed that the $Na^+/K^+ATPase$ activity in Maceobrachium nipponnese was significantly decreased in a concentration dependent manner. These results suggest that $Na^+/K^+ATPase$ activity in Maceobrachium nipponnese may possibly be used as a biomarker of lead pollution in aquatic ecosystem.