• Advances in Traditional Medicine
• /
• 제3권3호
• /
• pp.129-132
• /
• 2003

The hypoglycemic and hypolipidaemic effects of fenugreek seeds (Trigonella foenum graecum) are well established. Owing to the wide spread use of the seeds by healthy individuals and by diabetic patients we wanted to test whether the seeds can affect biological systems such as membrane transport function. In the present study fenugreek seed polyphenols were extracted and their effect on erythrocyte membrane-bound sodium-potassium adenosine triphosphatase $(Na^+/K^+-ATPase)$ activity was studied in vitro. Fenugreek seed polyphenols inhibited $Na^+/K^+-ATPase$ in erythrocyte membrane of diabetic and normal subjects. Maximum inhibition was observed at $100\;{\mu}l$ of extract containing 0.75 mM gallic acid equivalents. The uncoupling of membrane ATPases in vitro suggest that polyphenols from fenugreek seeds may possess a positive inotropic effect.

• 한국작물학회지
• /
• 제56권1호
• /
• pp.72-79
• /
• 2011

본 연구는 간이 수경재배법을 이용하여 보리의 알루미늄 스트레스 내성과 민감성 품종을 간편하고 빠르게 screen하는 방법을 소개하고, 선별된 품종간의 뿌리의 생장, 뿌리 조직의 염색, 알루미늄 함량, 원형질막의 $H^+$-ATPase의 발현 변화를 조사하여 분석하였다. l. 보리 65가지 품종을 간이 수경재배법을 이용하여 $20{\mu}M$ 알루미늄을 24시간 처리 후 뿌리생장의 차이로 내성 세 품종(자예2, 자예6, 모치무기)과 민감성 세 품종(흰쌀, 올쌀, 품2)을 선별하였다. 2. 알루미늄에 내성 품종은 알루미늄 처리 농도(0, 5, 10, $20{\mu}M$)에 따라 뿌리 생장 감소폭이 적었으나, 민감성 세 품종은 상대적으로 낮은 $5{\mu}M$ 농도에서부터 80%의 생장이 억제되었다. 3. 내성인 자예2와 민감성인 품2의 알루미늄 처리 후, 농도별(0, 5, 10, $20{\mu}M$), 시간별(3, 6, 12, 24시간)로 0.2% hematoxylin으로 염색 시 주로 apex에 3시간 이후부터 염색되었으며, 민감성 품2가 내성인 자예2에 비해 농도와 시간에 따라 그 피해 정도가 매우 심각하였다. 4. $20{\mu}M$로 24 시간 처리된 뿌리 apex(10 mm)의 알루미늄 함량을 측정한 결과, 내성인 자예2는 주당 47.1 nmol의 함량을 보여 주었으나, 민감성인 품2는 주당 64.9 nmol의 높은 함량을 보여 주었다. 5. 24시간 동안 $20{\mu}M$ 알루미늄을 처리한 뿌리 원형질막 $H^+$-ATPase 발현을 western blotting을 통해 분석한 결과, 내성인 자예2는 차이가 없었으나, 민감성 품2는 현저히 억제되었다. 이로 보아 원형질막 $H^+$-ATPase가 알루미늄의 내성 기작에 관여하는 것으로 보인다. 6. 본 연구를 통해 간이 수경재배와 hematoxylin을 이용한 염색으로 간단하고 빠르게 보리의 알루미늄 내성과 민감성 품종의 screening을 할 수 있었고, 보리뿐 아니라 쌀, 밀 등의 다른 종자에도 적용할 수 있을 것이다.

• The Korean Journal of Physiology
• /
• 제30권2호
• /
• pp.197-208
• /
• 1996

Endosomes lower their internal pH by an ATP-driven proton pump, which is critical to dissociation of many receptor-ligand complexes, the first step in the intracellular sorting of internalized receptors and ligands. Endosomes are known to exhibit n great range of pH values that can vary between 5.0 and 7.0 within a single cell although the factors that regulate endosomal pH remain uncertain. To evaluate the morphological and topological differences of endosomes in the different stages, confocal microscopy was used. The early endosomes labeled with fluorescein isothiocyanate-dextran for 10 min at $37^{\circ}C$ were identifiable at the peripheral and tubule-vesicular endosome compartment. In contrast, the late endosomes formed by 10 min pulse and 20 min trace were located deeper in the cytoplasm and showed more vesicular features than early endosomes. For the purpose of determining whether ATP-dependent acidification was heterogeneous and whether the differences in acidification were attributed to differences in the activity of $Na^{+}-K^{+}$-ATPase and/or $Cl^{-}$ channel, endocytic compartments were fractionated into subpopulation using percoll gradient and measured ATP-dependent acidification. While all fractions exhibited ATP-dependent acidification activity, both the initial rate of acidification and extent of proton translocation were lower in early endosomes and gradually increased in late endosomes. Phosphorylation by PKA and ATP enhanced ATP-dependent acidification in both early and late endosomes, hut there was no difference in the degree of enhancement by phosphorylation between two subpopulations. When ATP-dependent acidification was determined in the presence or absence of vanadate ($Na_{3}VO_{4}$) or ouabain, only early endosomes exhibited the vanadate or ouabain dependent stimulation of acidification activity, suggesting the inhibition of $Na^{+}-K^{+}$-ATPase. Therefore, it seems probable that the inhibition of early endosome acidification by $Na^{+}-K^{+}$-ATPase observed in vitro at least in part plays a physiological role in controlling the acidification of early endosomes in vivo.

• 한국동물학회지
• /
• 제23권3호
• /
• pp.137-148
• /
• 1980

토끼 골격근 小胞體의 ATPase 活性에 미치는 $Hg^{2+}, Cu^{2+}, Pb^{2+}, Cd^{2+}, Mn^{2+}$ 등 2價 陽이온을 영향을 비교 측정하였다. 이들 陽이온은 $Mn^{2+}$을 제외하고 모두 이 酵素의 活性을 阻害하였다. $Mn^{2+}$은 低濃度 (12.5-100 $\mu$M)에서는 오히여 活性을 증가시켰고, 그 보다 高濃度에서는 극히 약하게 阻害하였다. $Mn^{2+}$을 제외한 위의 2價 陽이온들의 阻害龍은 $Hg^2$가 가장 컸고 (阻害係數 Ki = 10$\mu$M), rm 다음이 $Cu^{2+}$ (Ki = 30$\mu$M), $Pb^{2+}$ (Ki = 120$\mu$M), $Cd^{2+}$ (Ki = 320$\mu$M)의 순이었다. 위의 4종의 陽이온들의 ATPase에 대한 阻害作用을 可逆的 非競爭的 阻害로 판정되었다.

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

• 한국환경농학회지
• /
• 제21권2호
• /
• pp.102-108
• /
• 2002

염류장애에 의한 작물의 생육저해 원인을 밝혀내기 위하여 상추를 대조양액과 대조양액에 30 mM 및 50 mM $KNO_3$를 첨가하여 염류농도를 높인 양액 등 3가지 조건에서 재배하였으며, 이때 이들 양액의 EC는 각각 1.0, 4.5, 6.5 dS/m 이었다. 뿌리세포의 원형질막 및 액포막에 위치한 $H^+$-ATPase 활성은 각각에 특이적 저해제인 vanadate와 $NO_3^-$를 이용하여 측정하였다. 대조양액에서 재배한 상추 뿌리의 ATPase 활성은 $356\pm1.5$ nmol/min/mg protein이었으며, 30 mM과 50 mM $KNO_3$를 첨가한 양액에서는 활성이 대조활성에 비하여 각각 1.6배, 1.9배 증가하였다. 이것은 상추가 염류장애시 뿌리조직의 ATPase 활성증가를 통하여 적응함을 보여주는 것이며, 활성증가는 주로 액포막 $H^+$-ATPase 활성증가에 의해 이루어짐을 확인하였다. 마이크로솜 ATPase 활성에 미치는 여러 가지 중금속 이온들의 효과를 측정하였으며, 중금속 이온은 100 ${\mu}M$ 농도에서 콩류에 따라 활성을 10$\sim$25% 저해하였다. 특히, $Cu^{2+}$는 주로 액포막 $H^+$-ATPase 활성을 저해함을 확인하였다. 본 연구의 결과로부터 상추는 염류집적 환경에서 뿌리의 ATPase 활성, 특히 액포막에 위치한 $H^+$-ATPase 활성을 증가시켜 적응하며, $Cu^{2+}$는 주로 액포막 $H^+$-ATPase 활성을 저해하는 성분으로 뿌리의 ATPase 활성변화 연구에 유용하게 이용될 수 있음을 확인하였다.

• Biomolecules & Therapeutics
• /
• 제23권5호
• /
• pp.458-464
• /
• 2015

Sennoside A (erythro) and sennoside B (threo) are dianthrone glycosides and diastereomers. We investigated their abilities to prevent the gastric lesions associated with diseases, such as, gastritis and gastric ulcer. To elucidate their gastroprotective effects, the inhibitions of $HCl{\cdot}tOH$-induced gastritis and indomethacin-induced gastric ulcers were assessed in rats. It was observed that both sennoside A and sennoside B increased prostaglandin $E_2$ ($PGE_2$) levels and inhibited $H^+/K^+$-ATPase (proton pump). In a rat model, both compounds reduced gastric juice, total acidity and increased pH, indicating that proton pump inhibition reduces gastric acid secretion. Furthermore, sennoside A and B increased $PGE_2$ in a concentration-dependent manner. In a gastric emptying and intestinal transporting rate experiment, both sennoside A and sennoside B accelerated motility. Our results thus suggest that sennoside A and sennoside B possess significant gastroprotective activities and they might be useful for the treatment of gastric disease.

• 약학회지
• /
• 제41권5호
• /
• pp.547-553
• /
• 1997

The purpose of this investigation was to determine the inhibition on $Na^+,\;K^+$-ATPase, cyclic AMP phosphodiesterase and platelet activation by marine sterols isolated from octocorals. Three marine polyhydroxysterols, 7${\alpha},\;8{\alpha}-epoxy-3b{\beta},\;5{\alpha},\;6{\alpha}-trihydroxycholestane (1),\;24-methyl-7{\alpha},\;8{\alpha}-epoxy-3{\beta},\;5{\alpha},\;6{\alpha}-trihydroxycholest-22-ene (2),\;and\;7{\alpha},\;8{\alpha}-epoxy-3{\beta},\;5{\alpha},\;6{\alpha}-trihydroxycholest-22-ene (3)$, were isolated from the Gorgonian Acabaria undulata. Five marine sterols(compound 4, 5, 6, 7, 8) were isolated from the soft coral Alcyonium gracillimum. Three marine polyhydroxysterols (1, 2, 3) and pregna-1. 20-diene-3-one (8) exhibit a potent inhibitory effect on rabbit platelet aggregation induced by collagen and thrombin. Those polyhydroxysterols also exhibit a potent inhibitory effect on cyclic AMP phosphodiesterase. Compound 6 with an unusual cyclic enolether exhibit a inhibitory effect on $Na^+,\;K^+$-ATPase.

• 대한약리학회지
• /
• 제26권1호
• /
• pp.35-49
• /
• 1990

A highly purified $(Na^+,\;K^+)-ATPase$ from the rectal gland of Squalus acanthias and from the electric organ of Electrophorus electricus has been used to raise antibodies in rabbits. The 97,000 dalton catalytic subunit and glycoprotein derived from the rectal gland of spiny shark were also used as antigens. The two $(Na^+,\;K^+)-ATPase$ holoenzymes and the two shark subunits were antigenic. In Ouchterlony double diffusion experiments, these antibodies formed precipitation bands with their antigens. Antibodies prepared against the two subunits of shark holoenzyme also formed precipitation bands with their antigens and shark holoenzyme, but not with eel holoenzyme. These observations are in good agreement with inhibitory effect of these antibodies on the catalytic activity of $(Na^+,\;K^+)-ATPase$ both from the shark and the eel, since there is very little cross-reaction between the shark anticatalytic subunit antibodies and the eel holoenzyme. The maximum antibodies titer of the anticatalytic subunit antibodies is found to be 6 weeks after the initial single exposure to this antigen. Multiple injections of the antigen increased the antibody titer. However, the time required to produce the maximum antibody titer was approximately the same. These antibodies also inhibit catalytic activity of $(Na^+,\;K^+)-ATPase$ vesicles reconstituted by a slow dialysis of cholate after solubilization of the enzyme in a presonicated mixture of cholate and phospholipid. In these reconstituted $(Na^+,\;K^+)-ATPase$ vesicles, effects of these antibodies on the fluxes of $Na^+$, $Rb^+$, and $K^+$ were investigated. Control or preimmune serum had no effect on the influx of $^{22}Na^+$ or the efflux of $^{86}Rb^+$. Immunized sera against the shark $(Na^+,\;K^+)-ATPase$ holoenzyme, its glycoprotein or catalytic subunit did inhibit the influx of $^{22}Na^+$ and the efflux of $^{86}Rb^+$. It was also demonstrated that these antibodies inhibit the coupled counter-transport of $Na^+$ and $K^+$ as studied by means of dual labeling experiments. However, this inhibitory effect of the antibodies on transport of ions in the $(Na^+,\;K^+)-ATPase$ vesicles is manifested only on the portion of energy and temperature dependent alkali metal fluxes, not on the portion of ATP and ouabain insensitive ion movement. Simultaneous determination of effects of the antibodies on ion fluxes and vesicular catalytic activity indicates that an inhibition of active ion transport in reconstituted $(Na^+,\;K^+)-ATPase$ vesicles appears to be due to the inhibitory action of the antibodies on the enzymatic activity of $(Na^+,\;K^+)-ATPase$ molecules incorporated in the vesicles. These findings that the inhibitory effects of the antibodies specific to $(Na^+,\;K^+)-ATPase$ or to its subunits on ATP and temperature sensitive monovalent cation transport in parallel with the inhibitory effect of vesicular catalytic activity by these antibodies provide direct evidence that $(Na^+,\;K^+)-ATPase$ is the molecular machinery of active cation transport in this reconstituted $(Na^+,\;K^+)-ATPase$ vesicular system.

• BMB Reports
• /
• 제31권1호
• /
• pp.44-47
• /
• 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.