• Proceedings of the Membrane Society of Korea Conference
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• 2004.05a
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• pp.55-58
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• 2004

Cell separation from peripheral blood was investigated using surface-modified polyurethane (PU) membranes with different functional groups. Both red blood cells and platelets could pass through unmodified PU and PU-SO$_3$H membranes, while the red blood cells preferentially passed through PU-N(C$_2$H$_{5}$ )$_2$ and PU-NHC$_2$H$_4$OH membranes. The permeation ratio of T and B cells was less than 25% for the surface-modified and unmodified PU membranes. CD34$^{+}$ cells have been recognized as various kinds of stem cells including hematopoietic and mesenchymal stem cells. The adhesiveness of CD34$^{+}$ cells on the PU membranes was found to be higher than that of red blood cells, platelets, T cells or B cells. Overall, the adhesiveness of blood cells on the PU membranes increased in the following order: red blood cells $\leq$ platelets ＜ T cells $\leq$ B cells ＜ CD34$^{+}$ cells. Treatment of PU-COOH membranes with a human albumin solution to detach adhered blood cells, allowed recovery of mainly CD34$^{+}$ cells in the permeate, while both red blood cells and platelets could be isolated in the permeate using unmodified PU membranes. The PU membranes showed different permeation and recovery ratios of specific cells depending on the functional groups attached to the membranes.mbranes.

• 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.

• The Korean Journal of Physiology
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• v.10 no.1
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• pp.1-5
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• 1976

The trypanocidal drug suramin, an impermeant polyanion, has been shown to be a powerful inhibitor of the calcium uptake and calcium-stimulated ATPase activity of sarcoplasmic reticulum (Fortes et al., 1974). In view of this finding, an attempt was made to investigate the effect of suramin on $Ca^{++}$ transport in resealed red cells and on $Ca^{++}$-activated ATPase in red blood cell membrane fragments (RBCMF). The results obtained are summarized as follows. 1. $Ca^{++}$ outflux from the resealed RBC was inhibited by suramin and the inhibitory action of suramin is proportional to the concentration of drug added inside the RBC preparation. When suramin is added both inside and outside the RBC preparation simultaneously, the magnitude of the inhibitory effect was more pronounced, suggesting that suramin inhibits both active $Ca^{++}-^{45}Ca$ exchange diffusion across the RBC membrane. 2. Suramin inhibits the $Ca^{++}$-activated ATPase of the RBCMF and the effect of inhibition by the drug was also concentration dependent. From the above results, it may be concluded that suramin inhibits $Ca^{++}$ transport across RBC membrane by inhibiting $Ca^{++}$-activated ATPase activity which has been known to be linked with active $Ca^{++}$ transport.

• Journal of Ginseng Research
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• v.19 no.1
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• pp.39-44
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• 1995

Total saponin from Korean red ginseng changed thermodynamic parameters of membranes from dipalmitoylphosphatidylcholine (DPPC) and ghost erythrocytes of human. In liposomes from DPPC, temperature of the main transition (Lb'-La) in liquid-crystalline phase increases by 0.2$^{\circ}C$ in average, but enthalpy does not change. Total saponin at a concentration of smaller than $10^5$% "stabilizes" the timid bilayers. At larger than 0.07 of saponin/DPPC ratio, saponin leads to an exclusion of the bound lipid molecules from the main phase transition into lamella liquid crystalline La-phase. Total saponin influences specifically all erythrocyte membrane transitions in a concentration-dependent manner, i.e. on the structures of all the main membrane skeleton proteins. A high structural specificity of saponin with membrane proteins, could be a base of specificity of physiological response of not only erythrocytes, but also other cells.her cells.

• Microbiology and Biotechnology Letters
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• v.30 no.4
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• pp.320-324
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• 2002

To establish a rapidly immunochemical identification on a dinoflagellate, Cochlodinium polykrikoides, a specific antigenic protein as a maker on the cell membrane was isolated. The cell membranes of C. polykrikoides and Gymnodinium sangineum were harvested by centrifugation after osmotic shock. The membrane proteins of both cells were solubilized in 50 mM Na-carbonate contained 1 mM DTT, and separated the proteins on SDS-PACE. Immune-blot on the solubilized membrane proteins of the both cells was performed with antiserum against the solubilized membrane proteins of C. polykrikoides. A 120 kDa membrane protein of C. polykrikoides had remarkablely different antigenicity from that of G. sangineum.

• Korean Journal of Veterinary Research
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• v.38 no.2
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• pp.273-279
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• 1998

The ability of bovine intact red blood cells to scavenge superoxide and hydrogen peroxide by superoxide dismutase, catalase and glutathione peroxidase was investigated. Intact red cells(up to 0.4%) suspensions did not inhibit ferricytochrome c reduction by superoxide in the superoxide generating system. On the other hand, intact red cell(0.4%) suspensions almost completely inhibit ferrocytochrome c oxidation by hydrogen peroxide. The ability of intact red cells to scavenge hydrogen peroxide was mainly attributed to either membrane bound catalase or glutathione peroxidase. The scavenge of hydrogen peroxide by 0.1~0.2% intact red cells showed a trend of dependence on mainly glutathione peroxidase. However, at blood cell concentration higher than 0.3%, the process depended upon peroxidase-independent scavengers like catalase. Enhancement of ferrocytochrome c oxidation by red cells treated with aminotriazole proved that the protection against hydrogen peroxide was due to catalase, while the protection in the presence of glutathione indicated scavenging effect of glutathione peroxidase against hydrogen peroxide.

• Journal of Microbiology and Biotechnology
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• v.27 no.2
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• pp.395-404
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• 2017

Fungal cell walls and cell membranes are the main targets of antifungals. In this study, we report on the antifungal activity of an ethanol extract from Paeonia lactiflora against Candida albicans, showing that the antifungal activity is associated with the synergistic actions of preventing cell wall synthesis, enabling membrane depolarization, and compromising permeability. First, it was shown that the ethanol extract from P. lactiflora was involved in damaging the integrity of cell walls in C. albicans. In isotonic media, cell bursts of C. albicans by the P. lactiflora ethanol extract could be restored, and the minimum inhibitory concentration (MIC) of the P. lactiflora ethanol extract against C. albicans cells increased 4-fold. In addition, synthesis of $(1,3)-{\beta}-{\small{D}}-glucan$ polymer was inhibited by 87% and 83% following treatment of C. albicans microsomes with the P. lactiflora ethanol extract at their $1{\times}MIC$ and $2{\times}MIC$, respectively. Second, the ethanol extract from P. lactiflora influenced the function of C. albicans cell membranes. C. albicans cells treated with the P. lactiflora ethanol extract formed red aggregates by staining with a membrane-impermeable dye, propidium iodide. Membrane depolarization manifested as increased fluorescence intensity by staining P. lactiflora-treated C. albicans cells with a membrane-potential marker, $DiBAC_4(3)$ ((bis-1,3-dibutylbarbituric acid) trimethine oxonol). Membrane permeability was assessed by crystal violet assay, and C. albicans cells treated with the P. lactiflora ethanol extract exhibited significant uptake of crystal violet in a concentration-dependent manner. The findings suggest that P. lactiflora ethanol extract is a viable and effective candidate for the development of new antifungal agents to treat Candida-associated diseases.

• Journal of Microbiology and Biotechnology
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• v.15 no.1
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• pp.80-85
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• 2005

Electrochemical control of the metabolic flux of W. kimchii sk10 on glucose and pyruvate was studied. The growing cell of W. kimchii sk10 produced 87.4 mM lactate, 69.3 mM ethanol, and 4.9mM lactate from 83.1mM glucose under oxidation condition of the anode compartment, but 98.9 mM lactate, 84.3mM ethanol, and 0.2 mM acetate were produced from 90.8 mM glucose under reduction condition of the cathode compartment for 24 h, respectively. The resting cell of W. kimchii sk10 produced 15.9 mM lactate and 15.2 mM acetate from 32.1 mM pyruvate under oxidation condition of the anode compartment, and 71.3 mM lactate and 3.8 mM acetate from 79.8mM pyruvate under reduction condition of the cathode compartment. The redox balance (NADH/$NAD^+$) of metabolites electrochemically produced from pyruvate was 1.05 and 18.76 under oxidation and reduction conditions, respectively. On the basis of these results, we suggest that the neutral red (NR) immobilized in bacterial membrane can function as an electron channel for the electron transfer between electrode and cytoplasm without dissipation of membrane potential, and that the bacterial fermentation of W. kimchii sk10 can be shifted to oxidized or reduced pathways by the electrochemical oxidation or reduction, respectively.

• The Korean Journal of Physiology
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• v.1 no.2
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• pp.151-156
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• 1967

Outward movement of hemoglobin and $K^+$ ion across rabbit erythrocyte membrane after heating, cooling and in acid medium was studied. One milliliter of rabbit blood was centrifuged and packed red cells were obtained. Packed red cells were resuspended by addition of 4 ml of 0.9% NaCl solution and were subjected to heating $(57^{\circ}C\;for\;5\;minutes)$ or cooling $(-4^{\circ}C{\sim}-8^{\circ}C\;of\;-10^{\circ}C{\sim}-11^{\circ}C\;for\;10\;minutes) $. For acid medium experiment packed ref cells were resuspended by addition of 4 ml of acid medium of PH 4.5 consisting of 0.01% glacial acetic acid in 0.85% NaCl solution and kept standing for 10 minutes. All red cell suspensions were centrifuged again and packed red cells were separated. This packed red cells were again suspended in 4 ml of NaCl solution of 0.8%, 0.7%, 0.6%, and 0.5% concentration respectively and kept standing for 20 minutes. The concentration of hemoglobin and $K^+$ in the supernatant of the above red cell suspensions were measured and the following results were obtained. 1. Outward movement of hemoglobin and $K^+$ was greatest in red cells subjected to heating. The movement paralled to the osmolal concentration gradient between extra- and intra-cellular phase of red cells. 2. In acid medium the outflux of hemoglobin and $K^+$ increased as compared to the control. 3. In red cells subjected to the cold of $-10^{\circ}C{\sim}-11^{\circ}C$ the outflux of hemoglobin and $K^+$ increased. Whereas in the environment of $-4^{\circ}C{\sim}-8^{\circ}C$ there was no change in the outflux of $K^+$. The he-moglobin outflux showed rather a decreased as compared to tile control.

• Microbiology and Biotechnology Letters
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• v.22 no.3
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• pp.290-295
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• 1994

Micelle, liposome and polyethylene glycol(PEG) were employed to reduce the cell mem- brane toxicity of Amphotericin B(Amp. B). Cholesterol-sulfate which can form a mixed micelle with Amp. B molecules was found very effective for the reduction of Amp. B toxicity. 0.01% of cholesterol-sulfate could reduce the toxicity of 5X 10$^{-6}$ M Amp. B by 90%. The required concent- ration of cholesterol-sulfate for the toxicity reduction was proportionally increased with increasing Amp. B concentration. PEG was also effective on the reduction of Amp. B toxicity. 2% PEG was required for the reduction of toxicity by 50%, regardless of Amp. B concentration. The liposome system showed an effective reduction of Amp. B toxicity on RBC, maintaining the antibiotic effect on Candida albicans as free drugs. This seems to be due to the fact that liposome bilayer plays a role of buffer system between ergosterol of fungi cell membrane and cholesterol of red blood cell membrane, which leads the redistribution of Amp. B between them, as the result, the reduction of drug toxicity on cell membrane.