• Bulletin of the Korean Chemical Society
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• 제29권9호
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• pp.1717-1722
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• 2008

The 70 kDa heat-shock protein (Hsp70) involved in various cellular functions, such as protein folding, translocation and degradation, regulates apoptosis in cancer cells. Recently, it has been reported that the green tea flavonoid (−)-epigallocatechin 3-gallate (EGCG) induces apoptosis in numerous cancer cell lines and could inhibit the anti-apoptotic effect of human Hsp70 ATPase domain (hATPase). In the present study, docking model between EGCG and hATPase was determined using automated docking study. Epi-gallo moiety in EGCG participated in hydrogen bonds with side chain of K71 and T204, and has metal chelating interaction with hATPase. Hydroxyl group of catechin moiety also participated in metal chelating hydrogen bond. Gallate moiety had two hydrogen bondings with side chains of E268 and K271, and hydrophobic interaction with Y15. Based on this docking model, we determined two pharmacophore maps consisted of six or seven features, including three or four hydrogen bonding acceptors, two hydrogen bonding donors, and one lipophilic. We searched a flavonoid database including 23 naturally occurring flavonoids and 10 polyphenolic flavonoids with two maps, and myricetin and GC were hit by map I. Three hydroxyl groups of B-ring in myricetin and gallo moiety of GC formed important hydrogen bonds with hATPase. 7-OH of A-ring in myricetin and OH group of catechin moiety in GC are hydrogen bond donors similar to gallate moiety in EGCG. From these results, it can be proposed that myricetin and GC can be potent inhibitors of hATPase. This study will be helpful to understand the mechanism of inhibition of hATPase by EGCG and give insights to develop potent inhibitors of hATPase.

• 대한의생명과학회지
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• 제6권3호
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• pp.165-170
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• 2000

Vacuolar (H$^{+}$)-ATPase (V-ATPase)는 multi-subunit로 구성된 단백질로서, proton pumping을 통해 세포내 산성화반응에 관여를 한다. 최근에 이 단백질이 synaptic vesicle에서도 발견된 것으로 보아 뇌 신경전달에 중요한 역할을 수행할 것으로 추정하고 있다. 우리는 흰쥐 뇌에서 분리한 mRNA를 주형으로 한 PCR 반응에서 16 kDa subunit의 V-ATPase cDHA를 클로닝할 수 있었고, 이의 염기서열 또한 결정하였다. 분리된 뇌 16 kDa V-ATPase의 coding sequence는 전체 468 bp로서 간에서 보고되었던 것과 동일한 크기였다. 단지 3' 말단의 염기 하나가 A에서 C로 바뀌어 있었는데 모두 alanine (GCA, GCC)을 지정하기 때문에 단백질의 일차구조에는 변화가 없는 것으로 확인되었다. 한편 rat brain cDNA library에서도 동일한 clone이 분리되었는데 역시 같은 부분에서 polymorphism이 발견되었고, RNA splicing 등 더 이상의 조직특이적 변화는 없었다. 본 연구는 16 kDa V-ATPase의 뇌에서의 기능과 신경말단에서의 neurotransmission 및 synaptic vesicle의 재순환 기전을 이해하는데 유용한 정보가 될 것이다.

• The Korean Journal of Physiology and Pharmacology
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• 제3권2호
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• pp.175-182
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• 1999

In the present study, the underlying mechanisms for diabetic functional derangement and insulin effect on diabetic cardiomyopathy were investigated with respect to sarcoplasmic reticulum (SR) $Ca^{2+}-ATPase$ and phospholamban at the transcriptional and translational levels. The maximal $Ca^{2+}$ uptake and the affinity of $Ca^{2+}-ATPase$ for $Ca^{2+}$ were decreased in streptozotocin-induced diabetic rat cardiac SR, however, even minimal amount of insulin could reverse both parameters. Levels of both mRNA and protein of phospholamban were significantly increased in diabetic rat hearts, whereas the mRNA and protein levels of SR $Ca^{2+}-ATPase$ were significantly decreased. In case of phospholamban, insulin treatment reverses these parameters to normal levels. Minimal amount of insulin could reverse the protein levels; however, it could not reverse the mRNA level of SR $Ca^{2+}-ATPase$ at all. Thus, the decreased SR $Ca^{2+}$ uptake appear to be largely attributed to the decreased SR $Ca^{2+}-ATPase$ level, which is further impaired due to the inhibition by the increased level of phospholamban. These results indicate that insulin is involved in the control of intracellular $Ca^{2+}$ in the cardiomyocyte through multiple target proteins via multiple mechanisms for the decrease in the mRNA for both SR $Ca^{2+}-ATPase$ and phospholamban which are unknown and needs further study.

• 약학회지
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• 제29권2호
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• pp.76-89
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• 1985

The effects of ginseng saponin on the activity, phosphorylation, [$^{3}$H] ouabain binding and light scattering (disruption) of purified $Na^{+}$ ,$K^{+}$ -ATPase isolated from the outer medulla of sheep kidney were compared to those of gypsophila saponin, sodium dodecylsulfate (SDS), and Triton X-100 on the same parameters. $Na^{+}$ , $K^{+}$ -ATPase activity, phosphorylation, and [$^{3}H$] ouabain binding were inhibited by ginseng saponin (triol>total>diol), SDS, or Triton X-100, but increased by gypsophila saponin. Low doses of ginseng saponin (3.mu.g saponin/.mu.g protein) decreased phosphorylation sites and ouabain binding site concentration (Bmax) without any change of turnover number and affinity for ouabain binding which were decreased by high dose of ginseng saponin (over 10.mu.g saponin/.mu.g protein), SDS or Triton X-100. On the other hand, gypsophila saponin increased the affinity without any change of Bmax for ouabain binding. Inhibition of $Na^{+}$ ,$K^{+}$ -ATPase activity by ginseng saponin and SDS or Triton X-100 appeared before and after decrease in light scattering, respectively. These data suggest that ginseng saponins (total, diol, triol saponin) inhibit $Na^{+}$ , $K^{+}$ -ATPase activity by specific direct and general detergent action at low and high concentrations, respectively, and this inhibitory action of ginseng sapornin to $Na^{+}$ , $K^{+}$ -ATPase is not general action of all saponins.

• 한국식품영양과학회지
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• 제14권1호
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• pp.77-81
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• 1985

사양기간(飼養期間)이 서로 다른 닭의 골격근에서 actomyosin 을 추출하여 추출성과 생물 활성을 비교하였다. 가슴부위에서 추출한 actomyosin의 추출성은 사양기간(飼養期間)이 3,4,5,6,7주(週)의 순으로 각각 184.5, 364.0, 784.8, 926.1, 985.2, 1020.1 mg/100g 이었고 다리부위는 각각 28.6, 70.8, 137.9, 139.5, 608.3 그리고 646.2mg/100g 이었다. 사양기간(飼養期間)이 3,6,8주(週)인 경우 24시간 추출한 actomyosin의 EDTA-ATPpase활성은 각각 0.68, 0.59, 0.50${\mu}M$ Pi/mg protein min. 이었고 Mg^{+2}$-ATPase 활성은 각각 0.66, 0.71, 0.75 $0.50\;{\mu}M$ Pi/mg protein min.이었고 Mg^{+2}$-ATPase 활성은 각각 0.66, 0.71, $0.75\;{\mu}moles$ Pi-mg protein/min.이었다. 사양기간(飼養期間)에 관계없이 actomyosin 의 3, 6, 8 Mg^{+2}$-ATPase 활성은 저(低) ion 강도에서 높은 활성과 rh(高) ion 강도에서 낮은 biphasic response를 나타내었고 $125\;{\mu}mole$ EGTA로서 Mg^{+2}$-ATPase 활성을 $0.1\;{\mu}mole/mg$ protein/min 이하로 저해시켰다.

• 한국식품영양과학회지
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• 제14권1호
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• pp.82-87
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• 1985

닭의 가슴부위 및 다리부위의 골격근(骨格筋)에서 myofibril, actomyosin 및 myosin을 추출하고 ATPase activity(${\mu}mole$ pi/mg protein/min)로서 나타낸 몇가지 생물학적(生物學的) 활성(活性)을 비교하였다. 가슴부위에서 추출한 actomyosin, myofibril 그리고 myosin의 $Mg^{+2}$-ATPase 활성(活性)은 0.05M KCl에서 0.80, 0.42, 0.40으로서 다리부위에서 추출한 단백질(蛋白質)의 활성(活性)인 0.69, 0.33, 0.28 보다 높았다. 가슴부위와 다리부위의 myosin의 ATPase 활성(活性)은 EDTA 농도보다 $Mg^{+2}$농도가 높아지면서 ATPase 활성(活性)을 1/10정도 저해(沮害)시켰고, $Ca^{+2}$ 농도는 $10^{-3}M$에서 400%까지 활성(活性)을 증가시켰다. 가슴부위와 다리부위에서 추출한 actomyosin의 용해되는 시점(始點)은 각각 0.1M KCl 및 0.15 M KCl이었고 myosin인 경우는 각각 0.25 M KCi 및 0.30 M KCl이었다.

• The Korean Journal of Physiology
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• 제29권2호
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• pp.269-277
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• 1995

Membrane vesicles were prepared by differential centrifugation from epithelial cells of porcine trachea. Total activity of microsomal ATPases was measured spectrophotometrically by a coupled enzyme assay. The steady-state activity of the enzyme was $329{\pm}10$ nmol/min mg protein. Thapsigargin, a specific antagonist of intracellular $Ca^{2+}-ATPase$, inhibited about 50% of the activity, leaving $178{\pm}18\;nmol/min .mg$ protein (n=6), indicating that the $Ca^{2+}-ATPase$ is one of the major microsomal ATPases. The microsomes used in this study appeared to be tight-sealed vesicles since they showed saturation in $^{45}Ca^{2+}$ uptake experiments. Inositol 1,4,5-trisphosphate $InsP_{3}, 4\;{\mu}M$, an agonist of $InsP_{3}$-sensitive $Ca^{2+}$ release channel ($InsP_{3}$, receptor), and Ca-ionophore A23187 $(10\;{\mu}M)$ induced $^{45}Ca^{2+}$ releases of 20% and 50% of stored $^{45}Ca^{2+}$, respectively. The addition of $(10\;{\mu}M\;InsP_{3}$ also increased the microsomal ATPase activity from $282{\pm}8$ nmol/min mg protein to $334{\pm}21$ nmol/min . mg protein in the intact vesicles. Similar increase in the activity was observed by making microsomes leaky (uncoupling) using the Ca-ionophore A23187. ;$InsP_{3}-induced$ effects were blocked by either thapsigargin or heparin suggesting that: 1) the $InsP_{3}-induced$ increase in ATPase activity is mediated by microsomal $Ca^{2+}-ATPase$, and 2) dissipation of $Ca^{2+}$ gradient across the microsomal membrane is responsible for the $InsP_{3}-induced$ effect. In order to test the dependence of the $Ca^{2+}-ATPase$ activity on the activity of $InsP_{3}-induced$ the activity of ATPases was monitored in various concentrations of free $Ca^{2+}$ using $EGTA-Ca^{2+}$ buffers. The $Ca^{2+}$-dependent biphasic change is the well-known character of $InsP_{3} receptor but not of microsomal $Ca^{2+}-ATPase$ in non-excitable cells; however, the activity of microsomal ATPase appeared biphasic and a maxim진 activity of $397{\pm}36nmol/min\;.mg$ protein was obtained in the solution containing 100 nM free $Ca^{2+}$. Below or above this concentration, the activity of ATPases was lower. These results strongly support a positive correlation of microsomal $Ca^{2+}-ATPase$ to the $InsP_{3}$ receptors in epithelial microsomes.

• 생물환경조절학회지
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• 제18권2호
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• pp.160-165
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• 2009

본 연구는 고온과 고습 조건 하에서 양파 화구의 총 단백질 발현과 원형질막 $H^{+}ATPase$ 영향을 조사하고자 조생종 '신선황'과 중생종 '맵시황'를 이용하여 실험을 수행하였다. '신선황'과 '맵시황' 품종의 양파 회구 개화전, 반개화, 그리고 만개 단계에서 단백질의 양생에는 차이를 보이지 않았지만 결실 단계에서는 유도 및 비유도되는 단백질이 현저하게 나타났다. 양파 화구 개화 후 실시한 고온과 고습처리 18일째의 양파두 품종의 단벡질도 현저하게 감소하였고 특히 고온처리구에서 더 감소되는 경향을 보였다. 원형절막 $H^{+}ATPase$ 발현을 western-blot으로 살펴본 결과, '신선황' 과 '맵시황'의 경우 대조구에서 원형질막 $H^{+}ATPase$ 단백질 발현이 유지 되는 반면에, 고온처리구에서는 두품종 모두 원형질막 $H^{+}ATPase$가 발현 되지 않았다. 고습처리구에서 중생종 '맵시황'약 원형질막 $H^{+}ATPase$는 발현 되었는데 조생종 '신선황'에서 발현되지 않았다. 이는 양파 종자 성숙단계에서 고온 조건을 조우하면 고습처리 보다는 단백질 및 원형질막의 $H^{+}ATPase$피해가 더 심각함을 보여 주는 결과이다.

• 한국환경농학회지
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• 제17권4호
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• pp.296-300
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• 1998

본 실험은 담배에서 염스트레스에 따른 생리적 반응의 연구결과(제1보)를 기초로, NaCl를 농도별로 처리하여 생체내에서 일어나는 생화학적인 변화의 구명을 통해 염해기작의 기초자료로 얻고자 수행한 결과를 요약하면 다음과 같다. 총단백질과 가용성단백질은 염농도가 높아질수록 감소하였으며 처리간에는 120mM까지는 완만히 감소하였고, 150mM에서는 급격한 감소를 나타냈다. 전기영동 패턴은 염농도의 증가에 따라 새로운 polypeptide band의 생성과 소멸은 없었으며 약 74Kd의 polypeptide band에서 30mM과 60mM까지는 뚜렷한 양이 증가하였고 90mM부터는 감소하였다. 엽록소함량은 염농도의 증가에 따라 감소하였으며 특히 염해에 의한 반응은 엽록소b보다는 엽록소a가 민감하였다. ATPase활성과 peroxidase의 활성은 염농도가 높아질수록 120mM까지는 일정하게 증가하였으나 150mM에서 급격히 증가하여 담배의 염해의 생화학적인 제한범위는 120mM로 나타났다.

• Journal of Photoscience
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• 제9권2호
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• pp.86-89
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• 2002

Blue light activates proton pump, and creates electrical gradient across the plasma membrane and drives $K^{+}$ uptake in stomatal guard cells. In this presentation, we provide evidence for regulatory mechanisms of the pump and the identification of blue light receptor. The pump is shown to be the plasma membrane H$^{+}$- ATPase and is activated through phosphorylation of the C-terminus. Phosphorylation occurred and 14-3-3 protein bound to the phosphorylation site. The binding of 14-3-3 protein was required for the H$^{+}$-ATPase activation. We also found that phot1 phot2 double mutant does not respond to blue light but other mutants respond to blue light by stomatal opening. However, all these mutants are capable of stomatal opening in the presence of fusicoccin, an activator of the H$^{+}$-ATPase. These results suggest that both photl and phot2 act as blue light receptors in guard cells.d cells.