• KSBB Journal
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• 제17권1호
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• pp.59-62
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• 2002

본 연구에서는 특히 환경변화에 민감한 오이, 호박을 선택하여 저온 스트레스에 의한 기작 반응을 인지하는 이온 채널들의 식물에 가해지는 수송능력의 변화에 따른 능동 운송과 스트레스 감응 능력에 따른 생리학적 규명을 위해 시료 처리가 복잡하고 장시간 소요되는 종래법에서 탈피하고자 바이오센서에 의한 진속, 간단, 경제적 측정법을 도입하였다. 시료한 개를 측정하는데 걸리는 시간은 3분이 소요되며 센서법과 종래법과의 측정결과 사이에 좋은 상관치를 나타내었다.

• 한국미생물·생명공학회지
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• 제27권5호
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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%.

• Journal of Plant Biology
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• 제33권4호
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• pp.325-332
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• 1990

Light membrane vesicles were isolated from the zucchini hypocotyl by floatation on ficoll density gradients and the proteins were solubilized with Triton X100. Three ATP-hydrolyzing enzymes were partially purified by ion-exchange and gel filtration chromatography and isoelectric focusing. There are plasma membrane-type ATPase whose activity was inhibited by vanadate but not by nitrate, tonoplast-type ATPase which was sensitive to nitrate but insensitive to vanadate and one having a phosphatase activity with a pI value different from that of an acid phosphatase. A fraction was obtained after DEAE-ion-exchange chromatography crossreacting with polyclonal antibodies against Ca2+ -ATPase from human erythrocytes.

• BMB Reports
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• 제28권5호
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• pp.387-391
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• 1995

In order to investigate whether phospholipase C (PLC) activity in oat celIs is regulated by Gprotein, we have characterized PLC in plasma membranes of oat tissues. To identify the purified plasma membrane, $K^+$-stimulated, $Mg^{2+}$-dependent ATPase activity was measured. The activity of ATPase was shown to be proportional to the concentration of membrane protein. To examine the PLC activity regulated by G-protein, we used the inside-out and outside-out plasma membrane mixture isolated from the oat cells. The plasma membrane mixture showed higher PLC activity than the one of the outside-out plasma membrane. This suggests that PLC activity is located at the cytoplasmic surface of plasma membrane. PLC activity in plasma membrane mixture was dependent on $Ca^{2+}$ with maximum activity at 100 ${\mu}m$ $Ca^{2+}$ and it was inhibited by 1 mM EGTA. Using Sep-pak $Accell^{TM}$ Plus QMA chromatography, we found that inositol 1,4,5-trisphosphate ($IP_3$) was produced in the presence of 10 ${\mu}m$ $Ca^{2+}$. The PLC activity in the membrane was enhanced by an activator of G-protein ($GTP{\gamma}S$) and not by an inhibitor ($GDP{\beta}S$). This indicates that a G-protein is involved in the activation of PLC in the plasma membrane of oat cells.

• Animal cells and systems
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• 제8권4호
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• pp.307-312
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• 2004

Fast kinetics of transient pH changes and difference spectrum formation have been investigated following mixing of ADP/ATP with partially purified plasma membrane PM-ATPase of the pathogenic yeast Candida albicans in the presence of five nutrients: glucose, glutamic acid, proline, lysine, and arginine and two analogs of glucose: 2-deoxy D-glucose and xylose. Average $H^+$- absorption to release ratio, indicative of population of ATPase undergoing complete hydrolytic cycle, was found to be 0.27 for control. This ratio varied between 0.25 (proline) to 0.36 (arginine) for all other compounds tested, except for glucose. In the presence of glucose, $H^+$- absorption to release ratio was exceptionally high (0.92). While no UV difference spectrum was observed with ADP, mixing of ATP with ATPase led to a large conformational change. Exposure to different nutrients restricted the magnitude of the conformational change; the analogs of glucose were found to be ineffective. This suppression was maximal in the case of glucose (80%); with other nutrients, the magnitude of suppression ranged from 40-50%. Rate of $H^+$- absorption, which is indicative of E~P complex dissociation, showed positive correlation with suppression of conformational change only in the case of glucose and no other nutrient/analog. Mode of interaction of glucose with plasma membrane $H^+$-ATPase thus appears to be strikingly distinct compared to that of other nutrients/analogs tested. The results obtained lead us to propose a model for explaining glucose stimulation of plasma membrane $H^+$-ATPase activity.

• Applied Biological Chemistry
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• 제46권2호
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• pp.84-89
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• 2003

$H^+-ATPase$ 활성을 조절할 수 있는 물질을 찾기 위하여 토마토 뿌리조직으로부터 마이크로솜을 분리하고 $La^{3+}$의 효과를 조사하였다. 원형질막 및 액포막에 위치하는 $H^+-ATPase$의 활성은 각각의 선택적 저해제인 vanadate와 $NO_3-$의 처리시 감소하여, $La^{3+}$이 원형질막 및 액포막 $H^+-ATPase$ 활성을 모두 저해함을 확인하였다. 원형질막과 액포막 $H^+-ATPase$ 활성을 50% 저해하는 $La^{3+}$ 농도인 Ki 값은 각각 57, $78\;{\mu}M$이었다. $La^{3+}$에 의한 저해효과는 Triton X-100을 처리한 leaky 마이크로솜에서도 얻어져, $La^{3+}$이 이온채널의 존재와 관계없이 $H^+-ATPase$의 활성을 직접적으로 저해함을 확인하였다. 한편, Lak의 활성저해 효과는 ATP 농도 증가로 감소하였고, ATP의 효과는 농도 의존적으로 나타났으며, 7 mM ATP 의해 $La^{3+}$에 의한 $H^+-ATPase$ 활성 저해가 완전히 억제되었다. 이러한 결과로부터 $La^{3+}$은 원형질막과 액포막의 $H^+-ATPase$들에 결합하여 ATP 결합친화력을 감소시킴으로써 활성을 저해하며, 뿌리조직 $H^+-ATPase$의 활성조절제로 이용이 가능함을 확인하였다.

• Journal of Photoscience
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• 제9권2호
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• pp.335-337
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• 2002

Blue light (BL) induces stomatal opening through activation of H$^{+}$ pump, which creates electrical gradient across the plasma membrane for $K^{+}$ uptake into guard cells. The pump is the plasma membrane H$^{+}$ -ATPase and is activated via phosphorylation of the C-terminus with concomitant binding of the 14-3-3 protein. The opening is initiated by the perception of BL through phototropin (phot), which are recently identified as BL receptors in stomatal guard cells. In this study, we provide the biochemical evidence for phots as BL receptors in stomatal guard cells. vfphot was phosphorylated reversibly by BL, and phosphorylation levels of vfphot increased earlier than those of the plasma membrane W-ATPase. BL-dependent phosphorylations of vfphot and H$^{+}$-ATPase showed similar fluence dependency. Staurosporin, an inhibitor of serine/threonine protein kinase, and diphenyleneiodonium chloride (DPI), an inhibitor of flavoprotein, inhibited BL-dependent phosphorylations of vfphot and H$^{+}$ -ATPase. These results indicate that vfphot acts as a BL-receptor mediating stomatal opening.l opening.

• 생물환경조절학회지
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• 제4권2호
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• pp.136-143
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• 1995

Canola(Brassica napus) 엽에서 추출한 미세막으로부터 PEG-dextran 2상분획법을 이용하여 세포막과 세포내막을 분리하였다. U$_2$ 상에 있는 원형질막의 $K^{+}$-ATPase의 특이활성도가 미세막에 비하여 $25^{\circ}C$에서 자란 canola는 6.6배, 1$0^{\circ}C$에서 4.6배 각각 증가되었다. 원형질막(U$_2$)은 미세막이나 세포내막(L$_2$) 보다 cytochrome-c-oxidase 활성이 적게 나타난 반면, 세포내막에서는 $K^{+}$-ATPase의 특이활성도가 가장 적게 나타났다. 1$0^{\circ}C$에서 생장한 canola의 18:3/18:2 률은 $25^{\circ}C$보다 29.2% 더 높게 나타났다. 원형질막의 2중결합지수는 1$0^{\circ}C$에서 생장한 canola가 $25^{\circ}C$에서 생장한 것보다 8.9% 더 증가되었으며 세포내막에서도 같은 경향으로써 1$0^{\circ}C$에서 19.7% 더 증가되는 현상을 보였다. 또한 엽록소 함량은 1$0^{\circ}C$에서 생장한 것이 $25^{\circ}C$에 비하여 17.3% 낮았다. Canola가 저온에서 생장시 주로 $C_{18}$ 지방산들이 변화되어, 세포막 내에 불포화 지방산이 많았으며, 그 중에서도 리롤렌산(18:3)이 크게 변화되는 현상을 보였다. 이러한 변화는 생리적으로 canola의 세포막이 저온에 살아가기 위한 하나의 수단으로 추정된다.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 2002년도 제9회 학술 발표회 프로그램과 논문초록
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• pp.9-11
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• 2002

Plasma membrane Na$^{＋}$-K$^{＋}$ ATPase (pump) is an essential component to maintain asymmetrical ion distribution across cell membrane. The Na$^{＋}$-K$^{＋}$ ATPase was discovered by Jens C. Skou in 1957 and since then physiological and biochemical properties of the enzyme have been extensively studied. Jens C. Skou was awarded the 1997 Nobel Prize in chemistry for his discovery of the Na $^{＋}$ - $K^{＋}$ ATPase.(omitted)

• 대한약리학회지
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• 제18권2호
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• pp.69-77
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• 1982

$Na^+,\;K^+-ATPase$ is a component of plasma membrane in almost all animal cell, and maintains ionic distribution and membrane potential of normal cell. In the mechanism of adrenergic transmission, it is relatively well known that drug-receptor combination leads to stimulate adenylate cyclase and so on. In the cholinergic transmisison, the mechanism is not well known but is simply interpreted as the change of membrane permeability results from acetylcholine receptor interaction. To study the relationship between cholinergic transmission and membrane $Na^+,\;K^+-ATPase$, the effect of carbachol on $Na^+,\;K^+-ATPase$ activity in rabbit erythrocyte membrane is studied. The results are summarized as follows. 1) Total ATPase, $Mg^{+2}-ATPase$ and $Na^+,\;K^+-ATPase$ of rabbit erythrocyte membrane show maximum activities at 1mM of tris-ATP. 2) Total ATPase activity tends to increase when treated with carbachol $(10-^{-9}M-10^{-3}M)$. 3) The $Mg^{+2}-ATPase$ activity also tends to increase when treated with carbachol $(10-^{-9}M-10^{-3}M)$. 4) The $Na^+,\;K^+-ATPase$ activity is inhibited when treated with carbachol $(10-^{-9}M-10^{-7}M)$. It is suggested that the inhibition of $Na^+,\;K^+-ATPase$ by cholinergic drugs may be considered as one part of mechanism of cholinergic transmission.