• Archives of Pharmacal Research
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• v.21 no.6
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• pp.707-711
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• 1998

The (Na,K)ATPase is responsible for generating the ionic gradients and membrane potentials by the exchange of intracellular $Na^+$ for $K^+$. It has been recentl y shown that (Na,K)ATPase is involved in the exocytic pathway of basic fibroblast growth factor (bFGF), although it is not known that bFGF is secreted to the outside of cell through direct interaction with (Na,K) ATPase. To understand the role for (Na,K)ATPase in the secretary pathway of bFGF, we have sought to identify the cytoplasmic domains of the alpha1 isoform of (Na,K)ATPase interacting with bFGF by yeast two-hybrid system. We have also investigated the interaction between the alpha2 isoform of (Na,K)ATPase and bFGF to find out whether the interaction is isoform-specific. We found that none of the cytoplasmic domains of (Na,K)ATPase isoforms interacted with bFGF. The result suggests that the interaction between bFGF and (Na,K)ATPase might be indirect, thus requiring other proteins which are involved in the formation of protein complexes for the interaction, although we cannot exclude the possibility that the interaction requires the element of the whole alpha subunit structure that was not present in the isolated alpha subunit cytoplasmic domains.

• The Korean Journal of Physiology
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• v.20 no.2
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• pp.157-164
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• 1986

Since it has been reported that vanadate inhibits $Ca^{++}-ATPase$ activity without affecting $Ca^{++}$ uptake, this study was undertaken to investigate the effects of vanadate on $Ca^{++}-ATPase$ activity and $Ca^{++}$ uptake in the sarcoplasmic reticulum of rat skeletal muscle. The following results were obtained. 1) $Ca^{++}$ activated ATPase activity of the intact sarcoplasmic reticulum was significantly inhibited when vanadate was added to the incubation medium at concentration greater than $10^{-6}\;M$. However $Mg^{++}$-ATPase activity of the intact SR was not affected by vanadate at concentrations ranging from $10^{-7}\;to\;10^{-4}\;M.$ Similarly, $Ca^{++}-ATPase$ activity in sonicated sarcoplasmic reticulum was significantly reduced by vanadate at a concentration $10^{-7}$ M or higher. 2) The uptake of $Ca^{++}$ by isolated sarcoplasmic reticulum was also inhibited by vanadate under the conditions where the turnover rate of $Ca^{++}-ATPase$ was made to increase. These results suggest that the inhibition of $Ca^{++}$ uptake by vanadate may be correlated with that of $Ca^{++}-ATPase$ if experimental conditions are properly set.

• Biomedical Science Letters
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• v.6 no.3
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• pp.165-170
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• 2000

Vacuolar (H$^{+}$)-ATPase (V-ATPase) is an intracellular protein which consists of multiple subunits. It carries out acidification by pumping protons in the cell. This enzyme has also been found in the synaptic vesicles and may play an important role in the neurotransmission. We cloned cDNA fragments encoding the 16 kDa subunit of V-ATPase from the rat brain by RT-PCR and PCR using total RNA or recombinant phage DNA as templates. They contained the full coding sequences (468 bp) and one nucleotide at 3' region turned out to be different (A to C) when compared to the liver counterpart. However, this polymorphic difference did not cause any significant change in the primary structure of the protein because both GCA and GCC code for alanine. Our study would contribute to the understanding of the function of 16 M)a V-ATPase in the brain and of the mechanisms of neurotransmission.

• Journal of the Korean Society of Food Science and Nutrition
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• v.14 no.1
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• pp.77-81
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• 1985

It was investigated about extractability and biological property(ATPase activity) of actomyosin from skeletal muscle of chi(:ken differed feeding period. The extractabilities of actomyosin from pectoral muscle were increased from 184.5 to 1020.1 mg per 100g muscle as feeding period prolonged from 3 weeks to 8 weeks. In case of leg-muscles, extractability was revealed the similar tendency as pectoral muscles. EDTA ATPase activity of actomyosin in various chicken muscles for 3 weeks feeding was 0.6 Brmole Piimg Protein/min., 0.59 for 6 Iveeks feeding and 0.50 for 8 weeks. The Ma^{+2}$-ATPase of actomyosin in various chicken muscles was showed inverted relationship with ionic strength. EGTA ($125\;{\mu}mole$)inhibited Ma^{+2}$-ATPase activity to below $0.1\;{\mu}mole$ Pi/mg protein/min. regardless the feeding period.

• Analytical Science and Technology
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• v.5 no.4
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• pp.477-484
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• 1992

The mitochondrion was purified at 44% sucrose layer from pleurotus florida by using ultracentrifuge and sucrose density gradient method. Optimum pH and temperature of ATPase and ATP synthase were pH 7.4, $60^{\circ}C$ and pH 7.5, $57^{\circ}C$ respectively, also their Km values were determined as 11.6mM and 8.4mM. ATPase was activated at 5~6mM ATP substrate concentration, then ATP synthase was 5~10mM range ADP. ATPase/ATP synthase were $Mg^{2+}$-dependent enzyme, partially inhibited by their substrate, and then showed an none competitive inhibition pattern by $G_{418}$. Amino acid composition of ATPase/ATP synthase was as follows, hydrophobic amino acid residue was 50.5%, small residue, 56.1%, hydrogen bonding residue, 43.7% and helix breaking residue, 55.2%. Phosphatidyl choline, phosphatidyl ethanolamine and phosphatidyl glycerol were contained but not phosphatidyl inositol and phosphatidyl serine. Palmitate(51.31%), stearate(18.32%) and unsaturated fatty acids($C_{18:1}$, $C_{18:2}$ and $C_{16:1}$) were predominated.

• Microbiology and Biotechnology Letters
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• v.22 no.1
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• pp.1-6
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• 1994

We have studied the relation between Ca$^{2+}$-ATPase and trigger peptidase(TPase) which are membeane protein well known as their significant role for signal transduction of mating pheromone in heterobasidiomycetous yeast. Rhodosporidium toruloides. We found out that there were Ca $^{2+}$-ATPase and TPase together in isolated calmodulim binding protein(CBP), usion calmodulin affinity column chromatography after solubilization of mation type a cell membrane protein, and that the dependence of enzyme activity of both the enzymes on Ca$^{2+}$, phospholipid and nonionic detergent are similar. However, Ca$^{2+}$-ATPase hed quite absolute dependence on calmodulin and, on the other hand, TPase didn't have any dependence. Judging from the fact that there are both enzymes in CBP which the dependence of calmodulin are quite different, we found out that both enzymes were made to their compound and existed in mating type a cell membrane.

• The Korean Journal of Mycology
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• v.19 no.3
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• pp.214-219
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• 1991

Adenosine-5'-triphosphatase$(F_1-ATPase)$ in the Lentinus edodes was fractionated by ammonium aulfate 30% saturation and purified by Sephadex G-200 gel filtration in three times. Three kinds of protein fractions of $F_1-ATPase$ were isolated from this mushroom, and fraction I and ll showed its activity for the substrate, adenosine-5'-triphosphate. Its optimum pH and temperature were found to be pH 7.6 and $58^{\circ}C$, and its thermal stability was stabled for 30 min. at $20-30^{\circ}C$. The Km value of this enzyme was 1.81 mM.

• The Korean Journal of Pharmacology
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• v.19 no.1
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• pp.101-106
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• 1983

Vanadium is widely distributed in animal tissues and it is supposed to be a regulator of Na-K-ATPase activity. The effect of sodium orthovanadate on Na-K-ATPase activity in rabbit kidney was measured in vitro and compared with that of ouabain. The influence of sodium orthovanadate on the renal function of rabbits was also investigated. 1) Na-K-ATPase activity was decreased by sodium orthovandate at the concentrations of $10^{-7},\;10^{-6},\;10^{-5}\;and\;10^{-4}\;M$ to 73.89, 36.49, 6.50 and 4.99% of the control activity respectively. 2) Na-K-ATPase activity was decreased by ouabain at the concentrations of $10^{-4},\;10^{-3}\;and\;10^{-2}\;M$ to 69.52, 22.84 and 3.88% of the control activity respectively. 3) Urine volume, urinary excretion of $Na^+,\;K^+\;and\;Cl^-$, clearances of inulin and p-amino-hoppuric acid were decreased until after 60 minutes following the administration of sodium orthovanadate 0.5 mg/kg intravenously $Na^+\;reasorption$ rate was not changed and mean arterial pressure was significantly elevated during 60 minutes after the administration of sodium orthovanadate.

• Journal of Microbiology and Biotechnology
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• v.7 no.3
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• pp.167-173
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• 1997

Everted membrane vesicles of Helicobacter pylori were prepared and the membrane-resided ATPases were characterized. For comparison, Escherichia coli membrane ATPases and hog gastric mucosal H,K-ATPase were employed. ATPase assay revealed that the composite enzyme pool was relatively low in specific activities, below 1/10 times than that found in E. coli. According to their inhibitory specificities, most of the ATPase pool appeared to belong to the P-type ATPase, sensitive to vanadate but not to azide. The enzyme pool was extraordinarily resistant against treatment by N,N'-dicyclohexylcarbodiimide (DCCD). Certain monovalent cations, e.g., $K^+$ or $NH_4^{+}$ stimulated the whole enzyme pool only in the presence of $Mg^{2+}$. On the contrary, $Ni^{2+}$ and $Zn^{2+}$ increased enzyme activity rather effectively without the aid of $Mg^{2+}$. Under a defined condition employed, H. pylori cells could retain the membrane ATPase pool to the extent of $17{\%}$ at pH 3.2. Moreover, its activity was most stable in acidic conditions (pH 5.4-6.4). However, cytoplasmic or peripheral ATPase pools were hardly detected under acidity (below pH 4.6).

• Microbiology and Biotechnology Letters
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• v.27 no.5
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• pp.354-358
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• 1999

In order to know the antifungal characteristics of saturated fatty acids having 6 to 12 carbons, their minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs) were estimated against Saccharomyces cerevisiae. Fatty acids from C6 to C11 exhibited increasing activity with chain length, but C12 fatty acid did not show activity at all. In relation to antifungal modes of actions, fatty acids investigated showed on inhibitory activity toward the plasma membrane H+-ATPase of Saccharomyces cerevisiae. Their inhibitions to the glucose-induced acidification and ATP hydrolysis caused by the proton pump were found to be in common wiht antifungal activities. At the test concentration of 1mM, hexanoic acid (C6) showed the lowest inhibition of about 30%, while undecanoic acid(C11) showed the strongest inhibition of over 90%. In addition, as seen with antifungal activity, the inhibitory activity of dodecanoic acid (C12) was suddenly reduced to less than 50%.