• Bulletin of the Korean Chemical Society
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• v.31 no.11
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• pp.3241-3246
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• 2010

NHERF ($Na^+/H^+$ exchanger regulatory factor) and E3KARP (NHE3 kinase A regulatory protein) play important roles in membrane targeting, trafficking and sorting of ion channels, transmembrane receptors and signaling proteins in many tissues. Each of these proteins contains two PDZ (PSD-95/Dlg-1/ZO-1) domains, which mediate the assembly of transmembrane and cytosolic proteins into functional signal transduction complexes. The interaction between NHERF and E3KARP was investigated by surface plasmon resonance spectroscopy (BIAcore), fluorescence measurement, His-tagged pull-down experiment, and size-exclusion column (SEC) chromatography. BIAcore experiments revealed that NHERF bound to E3KARP with an apparent $K_D$ of 7 nM. Fluorescence emission spectra of the NHERF-E3KARP complex suggested that the tight interaction between these proteins was accompanied by significant conformational changes in one or both. The CD spectra of NHERF and E3KARP show that the conformational changes of these proteins were dependent on pH and temperature. These results implicate that the NHERF-E3KARP complex allows intracellular signaling complexes to form through PDZ-PDZ interactions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.9
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• pp.1584-1587
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• 2004

The betaine content of Saliconia herbacea L. was determined by reverse-phase high performance chromatog-raphy on a C_(18) column. A 50% methanol extract was passed through a anion exchanger Ambelite IRA 400 (quaternary ammonium type, OH-) column and a strong cation exchanger Ambelite IR 120 (sulfonic acid type, $H^+$) column to remove amino acids, zwitter ions which are interfere with betaine analysis. The betaine extract was derivatized with 18-crown-6-ether and 4-bromophenacyl bromide (PBPB) for UV-labelling. Betaine in Saliconia herbacea L. was analysed on a mobile phase contained 13 mM sodium heptane sulfonic acid and 5 mM $Na_2SO_4$ in deionized water by isocratic elution for 30 min. The recovery ratio of betaine from Saliconia herbacea L. extract was 83.6%. The mean betaine value for Saliconia herbacea L. determined by the described method is 4.85 mg/mL with a standard deviation of 0.127.

• The Korean Journal of Physiology and Pharmacology
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• v.6 no.4
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• pp.173-181
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• 2002

The sinoatrial (SA) node is a complex and inhomogeneous tissue in terms of cell morphology and electrical activity. There are two models of the cellular organisation of the sinoatrial node: the gradient and mosaic models. According to the gradient model there is a gradual transition in morphology and electrical properties of SA node cells from the centre to the periphery of the SA node. In the mosaic model, there is a variable mix of atrial and sinoatrial node cells from the centre to the periphery. This review focuses on the cellular organisation of the rabbit sinoatrial node in terms of the expression of connexin (Cx40, Cx43 and Cx45), L-type $Ca^{2+}$ channel and $Na^+-Ca^{2+}$ exchanger proteins. These immunocytochemical data, together with morphological and electrophysiological data, obtained from the intact sinoatrial node and isolated sinoatrial node cells support the gradient model of the cellular organisation of the SA node. The complex organisation of the sinoatrial node is important for the normal functioning of the sinoatrial node: (i) it allows the sinoatrial node to drive the surrounding hyperpolarized atrial muscle without being suppressed by it; (ii) it helps the pacemaker activity of the sinoatrial node continue under a wide range of physiological and pathophysiological conditions; (iii) it helps protect the sinoatrial node from reentrant arrhythmias.

• Animal cells and systems
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• v.9 no.2
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• pp.95-100
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• 2005

Essential hypertension results from the complex interaction between genetic and environmental factors. A C825T polymorphism of the gene encoding G-protein ${\beta}3$ subunit (GNB3), associated with enhanced G-protein coupled signaling and increased $Na^+-H^+$ exchanger, has been implicated in the development of essential hypertension in several human populations, especially in Caucasian population. We examined the disease relevance of this candidate gene by performing an association study in a study group of Korean heritage. Participants comprised 109 essential hypertensives and 109 normotensives, respectively. Genotyping was performed with PCR-BsaJI restriction digestion method. Observed genotype frequencies were in Hardy-Weinberg equilibrium in all groups. Genotype and allele frequencies did not differ significantly between normotensives and essential hypertensives (P>0.05). However, the serum total cholesterol (TC) and LDL-cholesterol levels were significantly higher in subjects with the TT genotype compared to those with the CC or CT genotypes in normotensives of our study subjects (P<0.05). Thus, these results suggest that GNB3/C825T polymorphism might be significantly associated with abnormality in serum lipid metabolism.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.4
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• pp.510-522
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• 2008

Our earlier studies showed that estrogen was involved in the regulation of fluid reabsorption in adult mouse efferent ductules (ED), through estrogen receptor (ER) ${\alpha}$ and $ER{\beta}$ by modulating gene expression of epithelial genes involved in ion homeostasis. However, little is known about the importance of $ER{\alpha}$ in the ED during postnatal development. Based on previous findings, we hypothesized that there should be a difference in the expression of epithelial ion transporters and anion producers in the ED of postnatal wild type (WT) and estrogen receptor ${\alpha}$ knockout (${\alpha}ERKO$) mice. Using absolute, comparative and semi-quantitative RT-PCR along with immunohistochemistry, we looked at expression levels of several genes in the ED across postnatal development. The presence of estrogen in the testicular fluid was indirectly ascertained by immunohistochemical detection of the P450 aromatase in the testis. There was no immunohistochemically detectable difference in the expression of P450 aromatase in the testes and ER${\beta}$ in the ED of WT and ${\alpha}$ERKO mice. ER${\alpha}$ was only detected in the ED of WT mice. The absence of ER${\alpha}$ in the ED of postnatally developing mice resulted in differential expression of mRNAs and/or proteins for carbonic anhydrase II, $Na^+/H^+$ exchanger 3, down-regulated in adenoma, cystic fibrosis transmembrane regulator, and $Na^+/K^+$ ATPase ${\alpha}$. Our data indicate that the absence of ER${\alpha}$ resulted in altered expression of an epithelial ion producer and transporters during postnatal development of mice. We conclude that the presence of ER${\alpha}$is important for regulation of the ED function during the prepubertal developmental and postpubertal period.

• Parasites, Hosts and Diseases
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• v.54 no.1
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• pp.21-29
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• 2016

The sodium hydrogen exchanger 1 (NHE1), which functions in maintaining the ratio of $Na^+$ and $H^+$ ions, is widely distributed in cell plasma membranes. It plays a prominent role in pH balancing, cell proliferation, differentiation, adhesion, and migration. However, its exact subcellular location and biological functions in Toxoplasma gondii are largely unclear. In this study, we cloned the C-terminal sequence of T. gondii NHE1 (TgNHE1) incorporating the C-terminal peptide of NHE1 (C-NHE1) into the pGEX4T-1 expression plasmid. The peptide sequence was predicted to have good antigenicity based on the information obtained from an immune epitope database. After induction of heterologous gene expression with isopropyl-b-D-thiogalactoside, the recombinant C-NHE1 protein successfully expressed in a soluble form was purified by glutathione sepharose beads as an immunogen for production of a rabbit polyclonal antiserum. The specificity of this antiserum was confirmed by western blotting and immunofluorescence. The antiserum could reduce T. gondii invasion into host cells, indicated by the decreased TgNHE1 expression in T. gondii parasites that were pre-incubated with antiserum in the process of cell entry. Furthermore, the antiserum reduced the virulence of T. gondii parasites to host cells in vitro, possibly by blocking the release of $Ca^{2+}$. In this regard, this antiserum has potential to be a valuable tool for further studies of TgNHE1.

• Journal of Pharmaceutical Investigation
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• v.27 no.1
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• pp.57-64
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• 1997

$Amino-{\beta}-lactam$ antibiotics are absorbed by the dipeptide transporter in the small intestine. These uptakes are coupled to a proton influx. The inward proton gradient is partly induced by the $Na^+/H^+$ exchanger and calcium ion is involved in control of this antiport. Interaction between ampicillin which is one of the $Amino-{\beta}-lactam$ antibiotics and nifedipine which is one of calcium channel blocking agents was studied in rats in vivo and with rabbit jejunum mounted on the Sweetana/Grass diffusion cells in vitro. Bioavailability of ampicillin was increased significantly when nifedipine was co-administered orally in rats. There were no differences in the distribution phase and the elimination phase when ampicillin was given either alone or with nifedipine intravenously. Conditions for in vitro experiments were determined. The lift rate of $O_2/CO_2$ gas was controlled to 3 bubbles/sec and ampicillin was stable in the Kreb's buffer at pH 6.0. Absorption of ampicillin was the greatest when the completely-stripped serosal membrane was used. Transport of ampicillin from mucosal to serosal side in the rabbit jejunum was enhanced by 32% in the presence of nifedipine (p=0.059). Above results suggest that nifedipine might increase the plasma level of ampicillin via the improved absorption in the intestine rather than the reduction in the elimination or/and alteration in the distribution.

• Analytical Science and Technology
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• v.14 no.1
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• pp.59-63
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• 2001

A PVC membrane electrodes based on Fe(II)-dipyridyl-mefenamic acid ternary complex as ion exchanger were prepared using o-nitrophenyl octyl ether as a plasticizer. The 2,2'-dipyridyl, 4,4'-dipyridyl and 4,4'-dipyridyl-2,2'-dipyridyl were used as dipyridyl derivative ligand. The electrode dxhibits a fast stable and linear response for $10^{-5}-10^{-3}mol/L$ mefenamate with an anionic slope of -55.98, -49.47, -59.35mV/decade in pH 8.9 borate buffer solution respectively. Potentiometric selectivity measurements revealed negligible interferences from aromatic and aliphatic carboxylic acid salts.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.5
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• pp.527-534
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• 2006

The purpose of this study is the development of more effective filter-type polymer adsorbent for removal of anionic pollutants from wastewater. In order to synthesize the polymer adsorbent that possesses anionic exchangeable function, carboxyl(-COOH) group of PP-g-AA nonwoven fabric was converted into amine($-NH_2$) group by the chemical modification using diethylene triamine(DETA). FT-IR data indicate that amine group was introduced into PP-g-AA through amidation of grafted acrylic acid by reaction with DETA. The degree of amination increased with increase in the reaction time and temperature of the chemical modification process, and was significantly improved by the pre-swelling treatment of PP-g-AA with solvent and addition of metal chlorides as a catalyst in following order as $NH_4OH>MeOH{\geq}HCl{\geq}H_2O\;and\;AlCl_3>FeCl_3{\geq}SnCl_2{\gg}ZnCl_2{\geq}FeCl_2$, respectively. However, the addition of catalyst limited the reusability of DETA, hence was less useful from the viewpoint of cost effectiveness and waste management. The anion exchange capacity of the aminated PP-g-AA(PP-g-AA-Am) increased with increase in the degree of amination, but it reached maximum value at the degree of amination as about $50{\sim}60%$. The anion exchange capacity of PP-g-AA-Am was higher than those of commercial anion resins.

• Journal of Animal Environmental Science
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• v.16 no.3
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• pp.205-215
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• 2010

Geothermal heat pump system (GHPS) is an energy-efficient technology that use the relatively constant and renewable energy stored in the earth to provide heating and cooling. With the aim of using GHPS as a heating source, it's possibilities of application in farrowing house were examined by measuring environmental assessment and sow's performance. A total of 96 sows were assigned to 2 pig housings (GHPS and conventional housing) with 48 for four weeks in winter season. During the experimental period, indoor maximum temperature in GHPS-housing was measured up to $26.7^{\circ}C$, average temperature could maintain $21.2^{\circ}C$. The mean value of dust levels and $CO_2$, $NH_3$ and $H_2S$ gas emissions were decreased in GHPS-housing compare with those of conventional housing. Litter size, birth weight, parity and weaning weight did not differ between housings. However, feed intake of sow in GHPS-housing was lower than that of conventional housing. In energy consumption for heating, electric power consumption increased in GHPS-housing than the conventional housing, a 2,250 kwh increase, whereas there is no fuel usage for heater in GHPS-housing. Amount of ground water circulated for heating in cold weather for earth heat exchanger was 8.4-12.9 ton per day. In conclusion, GHPS may have environmental benefits and effectiveness of heating in farrowing housing and affect the performance in sows.