• Biomolecules & Therapeutics
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• 제3권3호
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• pp.205-209
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• 1995

The novel compound KH 3218 was synthesized and evaluated for its ability to inhibit the gastric H$^{＋}$＋ $K^{＋}$ ATPase activity in vitro as well as to lessen gastric acid secretion in vivo. KH 3218 inhibited rabbit gastric H$^{＋}$＋ $K^{＋}$ ATPase in a concentration and time dependent manner. $IC_{50}$/ value was estimated to be about 15 $\mu$M. The inhibition of the H$^{＋}$＋ $K^{＋}$ ATPase by KH 3218 was blocked by sulfhydryl reducing agents, dithiothreitol or $\beta$-mercaptoethanol. The inhibition of the enzyme was not reversible by 50 fold dilution of the incubation mixtures, suggesting the irreversible nature of the inactivation. In the pylorus-ligated rift, KH 3218 reduced the total acid output as compared with the control. In addition, KH 3218 was capable of inhibiting H. pylori urease activity. These data suggest that KH 3218 is a potent inhibitor for H$^{＋}$＋ $K^{＋}$ ATPase activity as well as for gastric acid secretion, and has a potential to be developed as a novel antiulcer agent.

• Applied Biological Chemistry
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• 제39권3호
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• pp.189-194
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• 1996

세포의 활성을 좌우하는 세포질내의 칼슘농도 조절기작을 이해하기 위하여, 전갈 Leiurus quinquestriatus hebraeus (Lqh) 에서 얻은 전갈독소의 세포내 칼슘농도 조절기능과 관련된 효소들의 활성변화에 미치는 효과를 조사하였다. 칼슘펌프와 칼슘채널 효소활성은 돼지의 호흡기 상피세포에서 분리된 마이크로솜에서 측정되었으며, 전갈 독소 Lqh는 온전한 마이크로솜 시료의 경우 총 ATPase의 활성을 약 32% 증가시켰고, Triton X-100나 $Ca^{2+}$ ionophore A23187을 처리한 마이크로솜 시료에서는 총 ATPase의 활성을 약 28% 증가시켰다. Lqh 독소에 의한 ATPase의 활성증가는 $Ca^{2+}-ATPase$의 특이적 저해제인 thapsigargin의 처리로 완전히 저해되었으며, 이것으로 전갈독소 Lqh가 마이크로솜에 위치한 $Ca^{2+}-ATPase$의 활성을 특이적으로 증가시킴을 확인할 수 있었다. 이러한 결과는 결국 Lqh 독소가 $Ca^{2+}-ATPase$의 활성화에 의해 마이크로솜의 $^{45}Ca^{2+}$ uptake를 증가시킬 것이라는 예상을 가능하게 하나, 실제로는 Lqh의 처리가 마이크로솜의 $^{45}Ca^{2+}$ uptake를 오히려 약 30% 감소시켰다. 예상되었던 Lqh에 의한 $^{45}Ca^{2+}$ uptake의 증가는 오직 $InsP_3$ 수용체 칼슘채널의 저해제인 Heparin의 존재시에만 얻어졌다. 이것은 Lqh 독소가 $Ca^{2+}-ATPase$의 활성화에 따른 $^{45}Ca^{2+}$ uptake를 증가시킴과 동시에 또한 $^{45}Ca^{2+}$ release를 유발시킴을 의미하며, Lqh 독소는 실제로 $InsP_3$에 의한 칼슘채널 활성화시에 얻어지는 것과 같은 정도의 $^{45}Ca^{2+}$ release를 유발시킴이 확인되었다. 위의 결과들로부터 Lqh독소에는 적어도 두 가지의 활성성분이 포함되어 있음을 알 수 있었고, 그중 하나는 $InsP_3$ 수용체 칼슘채널의 활성을, 다른 하나는 칼슘펌프의 활성을 촉진시킨다는 결론을 얻었다. 현재 Lqh 독소의 활성성분에 대한 화학적, 전기생리학적 특성들이 연구되어지고 있다.

• Applied Biological Chemistry
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• 제42권4호
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• pp.298-303
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• 1999

토마토 뿌리조직의 마이크로솜 ATPpase활성에 대한 중금속의 효과를 조사하기 위하여 뿌리조직으로부터 마이크로솜을 분리하였고, enzyme-coupled assay를 이용하여 마이크로솜 이온펌프(ATPase)의 활성을 측정하였다. 여러 가지 중금속 이온들 중 $Hg^{2+}$은 마이크로솜 ATPpase 활성을 농도 의존적으로 저해하였으며, $Gd^{3+}$과 $Fe^{3+}$, $La^{3+}$, $Zn^{2+}$, $Pb^{2+}$ 등은 마이크로솜 ATPpase의 활성을 저해하면서 동시에 assay에 사용된 효소를 저해하였다. 그러나, $Cs^+$과 $Ba^{2+}$은 마이크로솜 ATPpase 활성에 영향을 미치지 않았다. $Hg^{2+}$은 원형질막과 액포막에 위치하는 $H^+-ATPase$들의 활성을 $10\;{\mu}M$ 이상의 농도에서 현저히 저해하였고, 1 mM 이상의 농도에서 완전히 저해하였으며, 두 효소들에 대한 활성저해의 Ki 값은 각각 $80\;{\mu}M$, $58\;{\mu}M$로 나타났다. $Hg^{2+}$에 의해 저해된 ATPpase의 활성은 DTT의 농도를 증가시킴에 따라 회복되어, $Hg^{2+}$에 의한 ATPpase 활성저해는 가역적임을 확인하였다. 이러한 결과들은 $Hg^{2+}$이 원형질막과 액포막에 위치한 $H^+-ATPase$들을 비선택적이고 가역적으로 저해함을 보여준다.

• Biomolecules & Therapeutics
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• 제14권3호
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• pp.143-147
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• 2006

In the mouse leukemic monocyte cell line RAW 264.7, the vacuolar-type $(H^+)$-ATPase (V-ATPase) inhibitor bafilomycin $A_1$ at 10 and 100 nM decreased cell growth and survival as determined by 3-(4,5-dimethyl(thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in a concentration-dependent manner. At such concentrations, bafilomycin $A_1$ induced nitric oxide (NO) production through the expression of inducible nitric oxide synthase (iNOS). The bafilomycin $A_1$-induced NO production was inhibited by the NOS inhibitor $N^G$-monomethyl-L-arginine acetate (L-NMMA). Our findings suggest that the V-ATPase inhibitor bafilomycin $A_1$ induces NO production through the expression of iNOS protein.

• 한국환경과학회지
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• 제9권3호
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• pp.209-214
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• 2000

The preventive effects of sodium molybdate on the acute toxicity of lead were studied by investigating tissue accumulation of lead, changes of nerve conduction velocity and concentrations of metabolites related to function of sciatic nerve in rats treated with lead, sodium molybdate and both, respectively. In lead-intoxicated rat, the conduction velocity, myo-inositol concentration and $Na^{+}/K^{+}$ ATPase activity of sciatic nerve were decreased by about 33 %, 48 % and 58 %, respectively. However, sodium molybdate treatment significantly normalized the conduction velocity, $Na^{+}/K^{+}$ ATPase activity and myo-inositol concentration of sciatic nerve in lead-intoxicated rat. Also, sodium molybdate treatment decreased the contents of lead in blood and sciatic nerve through promotion of urinary excretion of lead. But sodium molybdate treatment did not affect the glucose concentration in sciatic nerve. These results suggest that sodium molybdate prevented peripheral neuropathy not only by reducing lead contents in sciatic nerve and blood, but also by enhancing $Na^{+}/K^{+}$ ATPase activity in sciatic nerve.

• 생명과학회지
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• 제6권1호
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• pp.1-5
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• 1996

Using differential hybridization, a cDNA clone was isolated fortuitously from Amaranthus viridis and sequenced. This nucleotide sequence exhibited 55.1% identity with vma6 which encodes the 36-kD subunit of the vacuolar proton transporting ATPase in Saccharmoyces cerevisiae. The predicted open reading frame encodes a protein of 221 amino acid sequence with a calculated molecular weight of 25,452 and reveals high levels of similarity with subunit D polypeptide of vacuolar H -ATP(e.g., 48.5, 52.1 and 49.3% identity to the vacuolar 36-kD chain of yeast, vacuolar 32-kD polypeptide IV of human and vacuolar 28-kD protein of bovine chromaffin granules, respectively). The hydropathy index computation revealed that this predicted protein is a peripheral protein. These results indicated that the predicted protein may play a sturctural role in the vaculor H -ATPase as does gamma subunit in V-type ATPase.

• Journal of Preventive Medicine and Public Health
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• 제23권4호
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• pp.371-390
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• 1990

Production of free radicals of superoxide anion in tissues by cadmium, activities of superoxide dismutase and catalase to protect tissue damages caused by the free radicals and ATPase that plays an important role in energy metabolism at cellular level were investigated. Experiments in vivo were conducted with liver, kidney and testicle tissue homogenates of rats adding $0.05{\sim}0.50mM$ cadmium chloride, and in vivo experiments administering single dose of 5 mg of cadmium/kg of body weight in 0.1% cadmium chloride solution intraperitoneally 48 hours prior to evisceration. Production of superoxide radicals in liver and testicle increased with addition of cadmium in vitro, but not in kidney. In vivo experiments, however, superoxide radicals slightly increased in liver and kidney but not in testicle. Superoxide dismutase (Cu, Zn-SOD and Mn-SOD), catalase and ATPase (total, $Mg^{++}-\;&\;Na^+,\;K^+-$) activity decreased in the presence of cadimium in dose dependent manner. Reduction of these enzyme activities varied not only with dosage of cadmium but also with type of tissue and between in vitro and in vivo experiment.

• The Korean Journal of Physiology and Pharmacology
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• 제17권4호
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• pp.275-281
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• 2013

Astrocytes are reported to have critical functions in ischemic brain injury including protective effects against ischemia-induced neuronal dysfunction. Na-K ATPase maintains ionic gradients in astrocytes and is suggested as an indicator of ischemic injury in glial cells. Here, we examined the role of the Na-K ATPase in the pathologic process of ischemic injury of primary cultured astrocytes. Chemical ischemia was induced by sodium azide and glucose deprivation. Lactate dehydrogenase assays showed that the cytotoxic effect of chemical ischemia on astrocytes began to appear at 2 h of ischemia. The expression of Na-K ATPase ${\alpha}1$ subunit protein was increased at 2 h of chemical ischemia and was decreased at 6 h of ischemia, whereas the expression of ${\alpha}1$ subunit mRNA was not changed by chemical ischemia. Na-K ATPase activity was time-dependently decreased at 1, 3, and 6 h of chemical ischemia, whereas the enzyme activity was temporarily recovered to the control value at 2 h of chemical ischemia. Cytotoxicity at 2 h of chemical ischemia was significantly blocked by reoxygenation for 24 h following ischemia. Reoxygenation following chemical ischemia for 1 h significantly increased the activity of the Na-K ATPase, while reoxygenation following ischemia for 2 h slightly decreased the enzyme activity. These results suggest that the critical time for ischemia-induced cytotoxicity of astrocytes might be 2 h after the initiation of ischemic insult and that the increase in the expression and activity of the Na-K ATPase might play a protective role during ischemic injury of astrocytes.

• 대한약리학회:학술대회논문집
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• 대한약리학회 2006년도 The 6th Congress of the Federation of Asian and Oceanian Physiological Societies
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• pp.118.2-118.2
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• 2006

• 한국동물학회지
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• 제23권2호
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• pp.61-68
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• 1980

발정주기에 EK라서 생쥐자궁의 alkaline phosphatase와 transport ATPases의 활성변화를 알아보기 위하여 정량적으로 분석하였다. 발정주기의 각 시기에 있어서 이 효소활성들의 비율은 대체로 그 양상이 서로 비슷하나, 발정기의 $K^+$-dependent와 $Na^+, K^+$-activated ATPases를 제외한 다른 효소들의 활성은 다른 어떤 시기보다도 유의하게 (p<0.025) 높았다. 즉, $K^+$-dependent와 $Na^+, K^+$-activated ATPases의 활성은 발정간기에서 발정기에 이르는 동안 무시할 정도이고, 다만 발정후기에 약간의 활성(0.04$\\sim$0.05 $\\mu$M/mg protein/hr), 총활성의 6$\\sim$7%)이 나타났다. 한편, 발정기에서 $Mg^++$-dependent phosphatase, transport ATPase와 alkaline phosphatase의 활성들은 급속히 현저하게 증가하였으며 각각 0.69(35%), 0.42(21%), 1.58(79%)였다. Alkaline phosphatase는 전 발정주기를 통해 0.60$\\sim$1.58(79$\\sim$90%)의 활성을 보여 그 주종을 이루었다. Alkaline phosphatase의 활성중에는 $Mg^++$-dependent의 것이 총활성의 12$\\sim$16%로 추정되었다. 그러므로 $K^+$-dependent와 $Na^+$-activated ATPases는 발정기 때에 자궁액의 누적을 조절하는 요인이 아니고 발정후기에는 자궁상피 속으로 내액을 재흡수하는 요인인 것으로 짐작되며, EH한 $Mg^++$-dependent phosphatase, transport ATPase 그리고 alkaline phosphatase는 생쥐의 자궁 상피세포에서부터 내액을 분지하는 데에 밀접히 관련되어 있는 것으로 사려된다.