• Title/Summary/Keyword: membrane fraction

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Subcellular Distribution of Heavy Metals in Organs of Bivalve Modiolus Modiolus Living Along a Metal Contamination Gradient

  • Podgurskaya, Olga V.;Kavun, Victor Ya.
    • Ocean Science Journal
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    • v.41 no.1
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    • pp.43-51
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    • 2006
  • Concentration and distribution of Fe, Zn, Cu, Cd, Mn, Pb, Ni among subcellular fractions (cellular membrane structures and cytosol) and Zn, Cu, Cd among cytoplasmic proteins in the kidney and digestive gland of mussel Modiolus modiolus living along a polymetallic concentration gradient were studied. It was found in the kidney of M. modiolus from contaminated sites that the Fe percent increased in the "membrane" fraction, whereas Zn, Pb, Ni and Mn percent increased in the cytosol compared to the kidney of the control mussel. Note kidney cytosol of M. modiolus from clean and contaminated sites sequestered major parts of Cu and Cd. In the digestive gland of M. modiolus from contaminated sites Fe, Zn, Cd, Mn, Ni percent increased in the "membrane" fraction, whereas Cu, Pb percent increased in the cytosol compared to digestive gland of control mussel. Gel-filtration chromatography shows kidney of M. modiolus contains increased metallothionein-like protein levels irrespective of ambient dissolved metal concentrations. It was shown that the metal detoxification system in the kidney and digestive gland of M. modiolus was efficient under extremely high ambient metal levels. However, under complex environmental contamination in the kidney of M. modiolus, the metal detoxification capacity of metallothionein-like proteins was damaged.

Study of Counter Diffusion in Isostatic Permeameters

  • Bianchi, F.;Pegoraro, M.;Zanderighi, L.
    • Korean Membrane Journal
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    • v.3 no.1
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    • pp.39-50
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    • 2001
  • The counter-diffusion of two gaseous substances permeating a polymeric membrane has been investigated both experimentally and theoretically. The aim of the study was to find mutual effects, if any, that could influence the permeability and diffusivity data. The experimental data were obtained with an isostatic permeameter operating at ambient pressure and 303 K: helium, nitrogen, carbon dioxide methane were used as permeating gas at different partial pressure; helium or nitrogen as equilibrating or carrier gas. No evident mutual effect of the counter-diffusing gas was observed. The theoretical analysis gave some insight into the phenomena and it was concluded that at near-atmospheric pressures, and in the absence of swelling phenomena no mutual interaction exists. On a theoretical basis any mutual interaction between diffusing and counter-diffusing gases could only occur: i) at high pressures , when the free movement of permeating gas molecules within the polymer is hindered by the counter-diffusing gas; ii) when a large part of the free volume fraction is occupied by the counter--diffusing gas; iii) swelling phenomena modify the structure and free volume fraction of the polymer.

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Interaction of Stomatin with Hepatitis C Virus RNA Polymerase Stabilizes the Viral RNA Replicase Complexes on Detergent-Resistant Membranes

  • Kim, Jung-Hee;Rhee, Jin-Kyu;Ahn, Dae-Gyun;Kim, Kwang Pyo;Oh, Jong-Won
    • Journal of Microbiology and Biotechnology
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    • v.24 no.12
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    • pp.1744-1754
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    • 2014
  • The hepatitis C virus (HCV) RNA genome is replicated by an RNA replicase complex (RC) consisting of cellular proteins and viral nonstructural (NS) proteins, including NS5B, an RNA-dependent RNA polymerase (RdRp) and key enzyme for viral RNA genome replication. The HCV RC is known to be associated with an intracellular membrane structure, but the cellular components of the RC and their roles in the formation of the HCV RC have not been well characterized. In this study, we took a proteomic approach to identify stomatin, a member of the integral proteins of lipid rafts, as a cellular protein interacting with HCV NS5B. Co-immunoprecipitation and co-localization studies confirmed the interaction between stomatin and NS5B. We demonstrated that the subcellular fraction containing viral NS proteins and stomatin displays RdRp activity. Membrane flotation assays with the HCV genome replication-competent subcellular fraction revealed that the HCV RdRp and stomatin are associated with the lipid raft-like domain of membranous structures. Stomatin silencing by RNA interference led to the release of NS5B from the detergent-resistant membrane, thereby inhibiting HCV replication in both HCV subgenomic replicon-harboring cells and HCV-infected cells. Our results identify stomatin as a cellular protein that plays a role in the formation of an enzymatically active HCV RC on a detergent-resistant membrane structure.

Purification of Hydrogenases from Purple Sulfur Bacterium Thiocapsa roseopersicina Using Various Applications of Chromatography (홍색 유황세근 Thiocapsa roseopersicina로 부터 생산되는 Hydrogenase의 각종 크로마토그래피에 의한 정제)

  • Choi, Eun-Hye;Oh, You-Kwan;Kim, Mi-Sun
    • Journal of Hydrogen and New Energy
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    • v.19 no.2
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    • pp.124-131
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    • 2008
  • Crude cytoplasmic fraction of phototrophic purple sulfur bacterium, Thiocapsa roseopersicina NCIB 8347, were initially prepared and purified by sonication, ultracentrifugation, ammonium sulfate fractionation and heat-treatment and it has been previously reported. Using various applications of chromatography far the purification of membrane-bound and soluble hydrogenases from heat-treated enzyme fraction were studied at present report. When the heat-treated enzyme preparation was applied to the anion column chromatography using Q-sepharose, Fraction I and II, which were extracted with the KCl 0-0.5 M gradient, showed the specific evolution hydrogenase activity 3.86 and 2.27 U/mg-protein respectively. Specific hydrogenase activitys of Fraction I and II were further increased to 4.35 and 7.46 U/mg-protein for Fraction I and to 2.49 and 4.41 U/mg-protein fur Fraction II respectively, when hydrophobic interaction column, Phenyl superose, and anion exchange column, Mono-Q, were applied. Size exclusion chromatography using superdex 200 concentrated the hydrogenase Fraction I and II to 9.19 and 7.84 U/mg-protein respectively at the final step of purification.

Effect of human milk on the angiogenesis and endothelial cell growth (혈관현성 및 혈관내피세포의 성장에 미치는 모유의 영향)

  • Lee, Ok-Hee;Kim, Jung-Sun;Shim, Kyung-Hee;Kim, Kyu-Won;Chung, Hae-Young
    • Journal of Life Science
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    • v.5 no.3
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    • pp.117-120
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    • 1995
  • Human milk was examined for antiangiogenic activities by using the chick embryo chorioallantoic membrane (CAM) assay and endothelial cell growth. The low molecular weight (20 KD>$\sim$ ) fraction of human milk stimulated the angiogenesis and increased the endothelial cell growth. These results suggest that the increase of angiogenesis and endothelial cell growth might be attributed to several growth factors and/or angiogenic factors in low molecular fraction (20 KD>$\sim$) of human milk.

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Effect of Alkaloidal Fraction from Cynanchi Radix on Lipid Peroxidation (우피소근(牛皮消根)의 알칼로이드 분획이 과산화지질 생성에 미치는 영향)

  • Lee, Dong-Ung;Shin, Uk-Seob;Yi, Su-Jin;Huh, Keun
    • YAKHAK HOEJI
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    • v.38 no.6
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    • pp.786-790
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    • 1994
  • The crude alkaloidal fraction of the root of Cynanchum caudatum Max.(Asclepiadaceae) was tested for the effects on the activities of free radical generating enzymes and the formation of lipid peroxide. Aldehyde oxidase was strongly inhibited to about 90% of the activity by treating 1.0 mg/ml of alkaloidal fraction, corresponding to competitive inhibition. Moreover, the formation of lipid peroxide which causes damage of cell membrane was reduced in proportion to the increasing alkaloid concentration. However, xanthine oxidase of which structure and function are similar to those of aldehyde oxidase was not inhibited by the alkaloidal fraction.

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Nonspecific Association of a 17 kDa Isoform of the Myelin Basic Protein with the Postsynaptic Density Fraction

  • Moon, Il-Soo
    • BMB Reports
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    • v.33 no.3
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    • pp.276-278
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    • 2000
  • The postsynaptic density (PSD), a large protein complex beneath the postsynaptic membrane, is notorious for its 'stickiness'. In order to understand the molecular composition of the PSD fraction, a 17 kDa protein band was isolated by electroelution from SDS-geis, and its partial amino acid sequence was determined from HPLC-purified tryptic peptides of the protein. Surprisingly, the amino acid sequence was identical to that of the previously reported 17 kDa isoform of the myelin basic protein (MBP), an essential protein in CNS myelin formation. Since the protein band represented ~2% of the total proteins in the 1 % n-octyl glucoside-insoluble PSD fraction, these results indicate that a significant amount of the 17 kDa isoform of MBP is tightly associated with the PSD during preparation of the PSD fraction.

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A Sperm Factor Inducing Second Polar Body Formation in Mouse Secondayy Oocyte

  • Park, Y.S;Min, S.H.
    • Korean Journal of Animal Reproduction
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    • v.26 no.4
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    • pp.369-375
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    • 2002
  • A sperm factor(s) for oocyte activation during fertilization has not been clearly identified. In this study to elucidate an oocyte activation factor(s), mouse sperm were sonicated and ultra-filtered with a 30 kilo-daltons (KD) cutoff membrane and the ultra-filtrate was then sequentially fractionated over Suporose 12 column and Superdex column, The recovered fractions were micro-injected into Mⅱmouse oocytes and second polar body formation (PBF) was examined. Suporose fraction RV2.10 prepared from sperm extract significantly increased PBF. Of Superdex fractions re-separated from Suporose fraction RV2.10, fraction RV2.12 also had the strongest PBF activity. By analyzing with micro-reverse phase column (URPC), the Superdex fraction RV2.12 appeared to be glutamic acid. In microinjection test, glutamic acid significantly increased PBF. This study suggests that glutamic acid should be a type of sperm factor for second polar body formation related to oocyte activation.

Respirometry for COD Fractionation of Wastewater (미생물 호흡률 분석에 의한 하수의 유기물 분류)

  • Choi, Younggyun;Kim, Gyudong;Kim, Heejun;Kim, Yunjung;Chung, Taihak
    • Journal of Korean Society of Water and Wastewater
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    • v.17 no.4
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    • pp.503-509
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    • 2003
  • COD fractionation of primary settled municipal wastewater was conducted by respirometry. RBCOD (Readily Biodegradable COD) fraction was analyzed to be 21% of influent TCOD. However, SCOD fraction, analyzed by physical separation using $0.45{\mu}m$ membrane filter, was about 31% of TCOD. Therefore, 10% of soluble inert COD was comprised in TCOD. It means that kinetic analysis of activated sludge system was impossible because serious error would be occurred if SCOD was used as a biodegradable soluble component instead of RBCOD estimated from respirometry. In this study, RBCOD fraction of raw wastewater could be analyzed by respirometry within the error range of 57%. In addition, SBCOD (Slowly Biodegradable COD) content could be determined by kinetic simulation of the experimental results. SBCOD showed about 2-fold higher fraction (38% of TCOD) as compared with RBCOD.

Studies on membrane permeability of yeast cells (i) (효모세포의 막투과성에 관한 연구)

  • 김종협;최연순;김희자
    • Korean Journal of Microbiology
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    • v.7 no.3
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    • pp.125-134
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    • 1969
  • The effect of heat treatment on membrane permeabilities of yeast's cells was studied, the amounts of efflux out of yeast cells were put to analysis, and fraction survival was also counted by viable plate counting method. Effects of nutritional substances on thermally injured yeast cells were also investigated under the highlight of reabsorption mechanism, then the relationship between permeability and surviving action in injured yeast cells are discussed.

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