• Title/Summary/Keyword: activated calcium

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Action of Theobromine on Sodium-Potassium activated ATPase in Red Cell Membrane (Theobromine이 적혈구막의 NaK ATPase의 활성도에 대한 작용)

  • Koh, Il-Sup
    • The Korean Journal of Physiology
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    • v.12 no.1_2
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    • pp.25-34
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    • 1978
  • The action of theobromine on the sodium plus potassium activated ATPase activity In the rabbit red cell membrane has teen investigated and the experiments were also designed to determine the mechanism of action of theobromine on the ATPase activity. The following results were observed. 1. The activity of the NaK ATPase from red fell membrane is stimulated by theobromine, and the concentration of theobromine for maximal activity is about 3mM. 2. The activating effect of theobromine on the ATPase, with a given concentration of potassium in the medium, is increased by raising the sodium concentration but activity ratio is decreased. 3. The activating effect of theobromine on the ATPase, with a given concentration of sodium in the medium. is increased by the raising the potassium concentration but activity ratio is decreased. 4. The NaK ATPase activity is increased by small amounts of calcium but decreased by larger amounts. The activity of the enzyme by theobromine is increased by small amounts of calcium but decreased by larger amounts. 5. The activating effect of theobromine on the ATPase was not related to the hydroxyl group of threonine and imidazole group of histicline. 6. The activating effect of theobromine on the ATPase is due to sulfhydryl group, amino group and carboxyl group of the enzyme of NaK ATPase.

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Bradykinin-Mediated Stimulation of Phospholipase D in Rabbit Kidney Proximal Tubule Cells

  • Park, Kyung-Hyup;Jung, Jee-Chang;Chung, Sung-Hyun
    • Biomolecules & Therapeutics
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    • v.2 no.1
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    • pp.39-46
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    • 1994
  • The present study was undertaken to demonstrate whether or not bradykinin activates a phospholipase D in rabbit kidney proximal tubule cells. By measuring the formation of [$^3$H]phosphatidic acid and [$^3$H]phosphatidylethanol we could elucidate the direct stimulation of phospholipase D by bradykinin. Bradykinin leads to a rapid increase in [$^3$H]phosphatidic acid and [$^3$H]diacylglycerol, and [$^3$H]phosphatidic acid formation preceded the formation of [$^3$H]diacylglycerol. This result suggests that some phosphatidic acid seems to be formed directly from phosphatidylcholine by the action of phospholipase D, not from diacylglycerol by the action of diacylglycerol kinase. In addition, the other mechanisms by which phospholipase D is activated was examined. We have found that phospholipase D was activated and regulated by extracellular calcium ion and pertussis toxin-insensitive G protein, respectively. It has also been shown that bradykinin may activate phospholipase D through protein kinase C-dependent pathway. In conclusion, we are now, for the first time, strongly suggesting that bradykinin-induced activation of phospholipase D in the rabbit kidney proximal tubule cells is mediated by a pertussis toxin-insensitive G protein and is dependent of protein kinase C.

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Gender-specific Association of the ANO1 Genetic Variations with Hypertension

  • Jin, Hyun-Seok;Jung, Dongju
    • Biomedical Science Letters
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    • v.21 no.3
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    • pp.144-151
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    • 2015
  • Development of hypertension is caused by complex contributions of genetic and environmental factors. In spite of the increased understanding of hypertension, genetic factors that contribute to hypertension largely remain elusive. ANO1 gene encoding a calcium-activated chloride channel has recently been reported to affect spontaneous hypertension in the animal model. In this report, we investigated possible association of the ANO1 gene with hypertension in human with ANO1 variants found in Korean population. Fourteen polymorphisms of ANO1 gene were analyzed to be associated with hypertension. Interestingly, the six polymorphisms that showed statistically significant association were all the male subjects. The highest significant SNP was rs7127129 (OR=1.14, CI: 1.02~1.28, additive P=0.023; OR=1.24, CI: 1.03~1.49, dominant P=0.025), and other five SNPs (rs2509153, rs11235473, rs10751200, rs10898827 and rs10899928) were also statistically associated with hypertension. Consequently, we found that the genetic variants of ANO1 present statistically significant associations with hypertension in human, especially, in male. To the best of our knowledge, this study is the first report describing association of genetic polymorphisms of ANO1 with hypertension in human.

Characterization of Calcium-Activated Bifunctional Peptidase of the Psychrotrophic Bacillus cereus

  • Kim Jong-Il;Lee Sun-Min;Jung Hyun-Joo
    • Journal of Microbiology
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    • v.43 no.3
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    • pp.237-243
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    • 2005
  • The protease purified from Bacillus cereus JH108 has the function of leucine specific endopeptidase. When measured by hydrolysis of synthetic substrate (N-succinyl-Ala-Ala-Pro-Leu-p-nitroanilide), the enzyme activity exhibited optimal activity at pH 9.0, $60^{\circ}C$. The endopeptidase activity was stimulated by $Ca^{++},\;Co^{++},\;Mn^{++},\;Mg^{++},\;and\;Ni^{++}$, and was inhibited by metal chelating agents such as EDTA, 1,10-phenanthroline, and EGTA. Addition of serine protease inhibitor, PMSF, resulted in the elimination of the activity. The endopeptidase activity was fully recovered from the inhibition of EDTA by the addition of 1 mM $Ca^{++}$, and was partially restored by $Co^{++}\;and\;Mn^{++}$, indicating that the enzyme was stabilized and activated by divalent cations and has a serine residue at the active site. Addition of $Ca^{++}$ increased the pH and heat stability of endopeptidase activity. These results show that endopeptidase requires calcium ions for activity and/or stability. A Lineweaver-Burk plot analysis indicated that the $K_m$ value of endopeptidase is 0.315 mM and $V_{max}$ is 0.222 ) is $0.222\;{\mu}mol$ of N-succinyl-Ala-Ala-Pro-Leu-p-nitroanilide per min. Bestatin was shown to act as a competitive inhibitor to the endopeptidase activity.

Action of Pilocarpine on Sodium-Potassium activated ATPase in Rabbit Red Cell Membrane (Pilocarpine이 토끼 적혈구막의 NaK ATPase의 활성도에 대한 작용)

  • Koh, Il-Sup
    • The Korean Journal of Physiology
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    • v.11 no.1
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    • pp.11-20
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    • 1977
  • The action of pilocarpine on the sodium plus potassium activated ATPase activity in the rabbit red cell membrane has been investigated and the experiments were also designed to determine the mechanism of action of pilocarpine on the ATPase activity. The following results were observed. 1. The activity of the NaK ATPase from red cell membrane is stimulated by pilocarpine, and the concentration of pilocarpine for maximal activity is about 3 mM. The pH optimum for the pilocarpine sensitive component is 8.0. 2. The activating effect of pilocarpine on the ATPase, with a given concentration of sodium .in the medium, is increased by raising the potassium concentration but activity ratio is decreased 3. The activating effect of pilocarpine on the ATPase, with a given concentration of Potassium in the medium, is increased by raising the sodium concentration but activity ratio is decreased 4. The NaK ATPase activity is increased by small amounts of calcium but decreased by 'larger amounts. The activity ratio of the enzyme by pilocarpine is decreased by small amounts .of calcium but decreased by larger amounts. 5. The activating effect of pilocarpine on the ATPase was not related to the sulfhydryl group of cysteine, the hydroxyl group of threonine or the imidazole group of histidine. 6. The activating effect of pilocarpine on the ATPase is due to amino group and carboxyl group of the enzyme of NaK ATPase

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Action of Anthraquinone on Sodium-Potassium activated -ATPase in Rabbit Red Cell Membrane- (Anthraquinone이 토끼 적혈주막의 NaK ATPase웨 활성도에 대한 작용)

  • Koh, Il-Sup
    • The Korean Journal of Physiology
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    • v.11 no.1
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    • pp.1-9
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    • 1977
  • Action of anthraquinone on the sodium plus potassium activated ATPase activity in the rabbit red cell membrane has been investigated and the experiments were also designed to determine the mechanism of action of anthraquinone on the ATPase activity. The following results were obtained 1. The activity of the NaK ATPase from red cell membrane is inhibited by anthraquinone and the concentration of anthraquinone for maximal inhibition is about 5mM. 2. The ratio of inhibition of NaK ATPase by anthraquinone, with a giving concentration of sodium in the medium, is increased by raising the potassium concentration. 3. The ratio of inhibition of NaK ATPase by anthraquinone, with a given concentration of potassium in the medium, is increased by raising the sodium concentration. 4. The action of anthraquinone on the NaK ATPase activity is inhibited by calcium ions and the ratio of inhibition is increased by small amounts of calcium but almost constant by larger amounts. 5. The inhibitory action of anthraquinone on the NaK ATPase activity was not related to the amino group of lysine, the hydroxyl group of threonine or the imidazole group of histidine. 6. The inhibitory action of anthraquinone on the ATPase activity is due to sulfhydryl group or the carboxyl group of the enzyme of NaK ATPase.

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Functional significance of rSK2 N-terminal region revealed by electrophysiology and Preliminary Structural Studies

  • Narae Shin;Kang, Gil-boo;Eom, Soo-Hyun;Park, Chul-Seung
    • Proceedings of the Korean Biophysical Society Conference
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    • 2003.06a
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    • pp.41-41
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    • 2003
  • Small conductance calcium-activated potassium channels (or SKCa channels) are potassium selective, voltage-independent, and activated by intracellular calcium concentration. These channels play important roles in excitable cells such as neuron in the central nervous system (Vergara et al., 1998). The activity of SKCa channels underlies the slow afterhyperpolarization that inhibits neuronal cell firing (Hille, 1991; Vergara et al.,1998). Until now, N-terminal region of rSK2 isn't characterized. To study the role of N-terminus, we constructed the N-terminal deletion mutant and characterized by electrophysiological means. Interestingly, N-terminal deletion mutant be trafficked to membrane couldn't evoke any ionic currents. Thus, N-terminal region has a role in functional rSK2 channel formation. To elucidate the function of N-terminal region, (His)6-conjugated protein was purified and filtrated by affinity column chromatography. Surprisingly, N-terminal region was shown in tetramer size that was supported by cross-linking result. Thus, we predicted that N-terminal region might be involved in the tetramerization of rSK2.

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Immunohistochemical Localization of Anoctamin 1 in the Mouse Cerebellum

  • Park, Yong Soo;Jeon, Ji Hyun;Lee, Seung Hee;Paik, Sun Sook;Kim, In-Beom
    • Applied Microscopy
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    • v.48 no.4
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    • pp.110-116
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    • 2018
  • Since a transmembrane protein, TMEM16A, also called anoctamin 1 (ANO1), was identified as a bona fide calcium ($Ca^{2+}$)-activated chloride ($Cl^-$) channel (CaCC), there have been many reports on its expression and function. However, limited information on ANO1 expression and function in the brain is still available. In this study, we tried to reexamine expression patterns of ANO1 in the mouse cerebellum and further characterize ANO1-expressing components by immunohistochemical analyses. Strong ANO1 immunoreactivity was observed as large puncta in the granule cell layer and weak to moderate immunoreactivities were observed as small puncta in the molecular and Purkinje cell layers. Double-label experiments revealed that ANO1 did not colocalize with cerebellar neuronal population markers, such as anti-calbindin and anti-NeuN, while it colocalized or intermingled with a presynaptic marker, anti-synaptophysin. These results demonstrate that ANO1 is mainly localized at presynaptic terminals in the cerebellum and involved in synaptic transmission and modulation in cerebellar information processing.

DEVELOPMENT OF SUSTAINABLE CEMENTLESS MORTARS

  • Keun-Hyeok Yang;Seol Lee;Sang-Ho Nam
    • International conference on construction engineering and project management
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    • 2009.05a
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    • pp.1630-1636
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    • 2009
  • Nine alkali-activated (AA) mortars were mixed and cured at water or air-dried conditions to explore the significance and limitation for the application of the combination of Ba and Ca ions as an alkali-activator. Ground granulated blast-furnace slag (GGBS) was used for source materials, and calcium hydroxide (Ca(OH)2) and barium hydroxide (Ba(OH)2) were employed as alkali activators. Test results clearly showed that the water curing condition was more effective than the air-dried curing condition for the formation of the denser calcium silicate hydrate (C-S-H) gels that had a higher molar Si/Ca ratio, resulting in a higher strength development. At the same time, the introduction of Ba(OH)2 led to the formation of 2CaO·Al2O3·SiO2·8H2O (C2ASH8) hydrates with higher molar Si/Al and Ca/Al ratios. Based on the test results, it can be concluded that the developed cementless mortars have highly effective performance and high potential as an eco-friendly sustainable building material.

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Generation and characterization of calmodulin-DHFR sandwich fusion protein

  • Han, Chang Hoon
    • Korean Journal of Veterinary Research
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    • v.48 no.3
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    • pp.243-250
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    • 2008
  • A calmodulin-dihydrofolate reductase (DHFR) sandwich fusion protein was generated by insertion of calmodulin into the $\beta$-bulge region of DHFR to observe the effects of structurally constraining the calmodulin structure. The calcium binding properties of the sandwich protein were almost identical to calmodulin. Similar to calmodulin ($10.7 {\mu}M$), the sandwich protein bound four equivalents of calcium, with half saturation ($K_{0.5}$) observed at a [$Ca^{2+}$] of $8{\mu}M$. However, nicotinamide adenine dinucleotide (NAD) kinase activation property of the sandwich protein was lower than that of calmodulin. The sandwich protein activated NAD kinase, but to only half of the level obtained with calmodulin. The K 0.5 for both calmodulin and the sandwich protein were approximately the same (1-2 nM). Methylation analyses of the sandwich protein show that insertion of calmodulin into DHFR results in a large decrease in methylation. The $V_{max}$ observed with the sandwich protein (95 nmole/min/ml) was only 22% of the value observed with calmodulin (436 nmol/min/ml) in the presence of calcium. Addition of trimethoprim to the reaction significantly inhibited the observed methylation rate. Overall, the data suggest that the insertion of calmodulin into the DHFR structure has little effect on calcium binding by the individual lobes of calmodulin, but may constrain the lobes in a manner that results in altered interaction with the calmodulin-dependent proteins, and severely perturbed the methyltransferase recognition site.