• Journal of Environmental Health Sciences
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• v.19 no.4
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• pp.83-89
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• 1993

To evaluate an effect of methanethiol on a cause of erythrocyte membrane damage in rats, methanethiol was given at 11.25 rag/100 g body weight, and after 4 hr, the animals were sacrifled, the activities of Na$^+$/K$^+$ ATPase, protein contents in partial purified erythrocyte membrane and erythrocyte indices were determined Concomitantly, in vitro, effect of methanethiol on the erythrocyte fragility, Na$^+$/K$^+$ ATPase activity and its kinetics in various concentration of substrate from the preincubated erythrocyte membrane with methanethiol were demonstrated. The spleen weight per body weight (%) and MCV of erythrocyte in methanethiol-treated rats were more increased than those in the control group. The Na$^+$/K$^+$ ATPase activities in erythrocyte membrane were more decreased in methanethiol-treated rats than those in the control group. The apply of 0.05 ng rat whole blood to the 0.24 mg/ng of methanethiol solution in isotonic condition showed the complete hemolysis. The Na$^+$/K$^+$ ATPase activity in preincubated erythrocyte membrane with methanethiol at 37$\circ$C showed the dual effect and the K$_m$ value of Na$^+$/K$^+$ ATPase was higher in the preincubated erythrocyte membrane with methanethiol than that in the preincubated erythrocyte membrane omitted the methanethiol. These results suggest that the methanethiol may induce the damage of rat's erythrocyte membrane due to a change in substrate binding affinity of Na$^+$/K$^+$ ATPase.

• Journal of Microbiology and Biotechnology
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• v.32 no.1
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• pp.37-45
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• 2022

The fungal cell wall and membrane are the principal targets of antifungals. Herein, we report that myricetin exerts antifungal activity against Candida albicans by damaging the cell wall integrity and notably enhancing the membrane permeability. In the presence of sorbitol, an osmotic protectant, the minimum inhibitory concentration (MIC) of myricetin against C. albicans increased from 20 to 40 and 80 ㎍/ml in 24 and 72 h, respectively, demonstrating that myricetin disturbs the cell wall integrity of C. albicans. Fluorescence microscopic images showed the presence of propidium iodide-stained C. albicans cells, indicating the myricetin-induced initial damage of the cell membrane. The effects of myricetin on the membrane permeability of C. albicans cells were assessed using crystal violet-uptake and intracellular material-leakage assays. The percentage uptakes of crystal violet for myricetin-treated C. albicans cells at 1×, 2×, and 4× the MIC of myricetin were 36.5, 60.6, and 79.4%, respectively, while those for DMSO-treated C. albicans cells were 28.2, 28.9, and 29.7%, respectively. Additionally, myricetin-treated C. albicans cells showed notable DNA and protein leakage, compared with the DMSO-treated controls. Furthermore, treatment of C. albicans cells with 1× the MIC of myricetin showed a 17.2 and 28.0% reduction in the binding of the lipophilic probes diphenylhexatriene and Nile red, respectively, indicating that myricetin alters the lipid components or order in the C. albicans cell membrane, leading to increased membrane permeability. Therefore, these data will provide insights into the pharmacological worth of myricetin as a prospective antifungal for treating C. albicans infections.

• Proceedings of the Korean Biophysical Society Conference
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• 1998.06a
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• pp.16-16
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• 1998

The role of phospholipids in the membrane binding and subsequent insertion of the microsomal protein rabbit cytochrome P450 (P450) lA2 into phospholipid bilayers was investigated. The insertion of P450 lA2 into phospholipid bilayers was determined by the amount of quenching of Trp fluorescence of P450 lA2 by pyrene and brominated and doxyl-labeled phospholipids.(omitted)

• The Korean Journal of Physiology
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• v.8 no.1
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• pp.45-53
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• 1974

The effects of kanendomycin on the potassium permeability in the rabbit erythrocyte membrane are investigated and the results are summarized as follows. 1. Kanendomycin causes the efflux of $K^+\;and\;influx\;of\;Na^+$ across the rabbit erythrocyte membrane. 2. Osmotic resistance of kanendomycin treated erythrocytes is diminished. This diminution of osmotic resistance is more pronounced by increasing concentration of kanendomycin and longer incubation time. But osmotic resistance is rather increased in the presence of lower concentration of kanendomycin. 3. Cysteine and glutathione have little influence on $K^+$ efflux induced by kanendomycin. 4. EDTA has no effect on the increase in $K^+$ outflux by kanendomycin while PCMB augments slightly on $K^+$ outflux. 5. Kanendomycin inhibits $Ca^{++}$ binding competitively to rabbit erythrocyte membrane fragments.

• Microbiology and Biotechnology Letters
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• v.22 no.1
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• pp.1-6
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• 1994

We have studied the relation between Ca$^{2+}$-ATPase and trigger peptidase(TPase) which are membeane protein well known as their significant role for signal transduction of mating pheromone in heterobasidiomycetous yeast. Rhodosporidium toruloides. We found out that there were Ca $^{2+}$-ATPase and TPase together in isolated calmodulim binding protein(CBP), usion calmodulin affinity column chromatography after solubilization of mation type a cell membrane protein, and that the dependence of enzyme activity of both the enzymes on Ca$^{2+}$, phospholipid and nonionic detergent are similar. However, Ca$^{2+}$-ATPase hed quite absolute dependence on calmodulin and, on the other hand, TPase didn't have any dependence. Judging from the fact that there are both enzymes in CBP which the dependence of calmodulin are quite different, we found out that both enzymes were made to their compound and existed in mating type a cell membrane.

• Journal of Photoscience
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• v.9 no.2
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• pp.308-310
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• 2002

Bacteriorhodopsin (bR) and halorhodopsin (hR), which exist in the membrane of Halobacterium salinarum, are light-driven ion pumps. In spite of high similarity of primary and tertiary structures between bR and hR, these membrane proteins transport different ions, proton and chloride, in the opposite direction. From alignment of the amino acid sequences, Thr-89 of bR is homologous to Ser-l15 of hR from Halobacterium salinarum (shR). X-ray structure of shR has revealed that OH group of this residue directly interacts with CI$\^$-/ Thus, Ser-lI5 of shR is expected to play an important role in CI$\^$-/ binding and transport. In this study, we expressed wild type hR from Natronobacterium pharaonis (PhR) and Sl30A, which corresponds to Ser-l15 of shR, in E. coli in order to clarify binding affinity of chloride ion and photocycle reactions. From the titration with CI$\^$-/, affinity of Sl30A became quite lower than that of WT (WT 6 mM, Sl30A 89 mM). Furthermore, from the flash photolysis with pulse laser of λ$\_$max/ at 532 nm, the reaction rate of SI30A from 0 intermediate to hR ground state was found to become apparently slower than that of WT. The singular value decomposition (SVD) and global fitting analyses of the photocycles were performed to identify all photointermediates and determine the reaction rates.

• Journal of Life Science
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• v.2 no.2
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• pp.97-107
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• 1992

Strichartz and Richie have suggested that the mechanism of sodium donductance block of local anesthetics involves their interaction with a specific binding site within the sodium channel. However, there is evidence that local anesthetics can interact electrostatically with membrane proteins as well as membrane lipids. Whether or not all actions of local anesthetics are mediated by common site remains unclear. Thus, it can not be ruled out that local anesthetics concurrently interact with neuronal membrane lipids since sodium channels were found to be tightly associated with membrane lipids through covalent or noncovalent bonds. In summary, it is strongly postulated that local anesthetics, in addition to their direct interaction with sodium channels, concurrently interact with membrane lipids, fluidize the membrane, and thus induce conformational changes of sodium channels, which are known to be tightly associated with membrane lipids.

• Asian Journal of Turfgrass Science
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• v.11 no.1
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• pp.45-58
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• 1997

Pigments and thylakoid membrane proteins were investigated in wild type and PS I- mutants from Synechocystis sp. PCC6803 Comparing morphological features, B2 was less fluorescent than the other strains. The contents of chlorophyll a were propotional to the FNR activity in thylakoid membrane. The FNR activity of mutants was lower than that of wild type. In the result of pigments analysis, mutants had smaller cholophyll a than that of wild type. The major carotenoid was found to he $\beta$-caroene, but aeaxanthin was barely detected in thylakoid membrane of mutants. The polypeptide, 14.8kD was detected by electrophoresis in mutants. It was considered to be the modification of 15.4kD in wild type. Membrane polypeptides of 17.6 and 19.7kD were not detected in mutants. In the result of western blotting, subunit I was detected in all strains, but subunit II was barely detected in mutants. Subunit II was not detected in B2 at all. In view of the results so far achieved, the changes of contents of chlorophyll and zeaxanthin were affected by the defficiency or modification of functional domain in subunit I. Also the modification in subunit I affected the subunit II- binding site in PS I. As the result, efficiency of photosynthesis was decreased. Key words: Synechoystis sp. PCC6803, PS I - mutant, Photosynthetic efficiency, Pigment,Thylakoid membrane proteins, Subunit I, II.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.7
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• pp.1162-1166
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• 2013

Proteins from sunflower seeds were hydrolyzed with Alcalase and Flavourzyme to isolate iron-binding peptides. The optimal hydrolysis conditions were determined. Hydrolysates were filtered under a 3 kDa membrane and iron-binding peptides separated from the hydrolysates using ion exchange and gel permeation chromatographic methods. A fraction with the highest iron-binding activity (Fe/peptide, 0.69), F22, was obtained. These results suggest that fractions isolated from sunflower seed protein hydrolysates can be applied toward the production of iron supplements.

• Textile Coloration and Finishing
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• v.7 no.2
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• pp.40-46
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• 1995

In order to study the dyeability of wool S-cyano ethylated wool-keratine(SCEK) as a model compound of wool was prepared from the reaction of reduced merino wool fiber and acrylonitrile. The binding of acid dyes(methyl orange and it's homologs) by SCEK over the temperature 60~9$0^{\circ}C$ were investigated. The first binding constants and the thermodynamic parameters in the course of the binding were evaluated. It was found that at the 60~9$0^{\circ}C$ range complex formation between the dye and SCEK is associated with an exothermic enthalpy change and a positive entropy change. The enthalpy and entropy changes of the binding are of the order of -4.5 kcal/mole and 8.5 eu, respectively, for each dye measured. Thus the binding is mainly enthalpy-controlled. Furthermore the effect of the alkyl chain length of the dye on both the ΔH$^{\circ}$and ΔS$^{\circ}$value is not prounced. Also temperature dependences of the ΔH$^{\circ}$and ΔS$^{\circ}$values were not obserbed.