scholarly journals The use of horseradish peroxidase–lectin conjugates to monitor the purity of plasma-membrane preparations obtained from isolated cells

1981 ◽  
Vol 198 (2) ◽  
pp. 421-423 ◽  
Author(s):  
J. Paul Banga ◽  
Philip Penfold ◽  
Ivan M. Roitt
Keyword(s):  
Plasma Membrane ◽  
Horseradish Peroxidase ◽  
Positive Reaction ◽  
Wheat Germ Agglutinin ◽  
Wheat Germ ◽  
Plasma Membranes ◽  
Membrane Vesicles ◽  
Ultrastructural Examination ◽  
Isolated Cells ◽  
Intact Cells

The plasma membranes of viable murine EL4 tumour cells were labelled with horseradish peroxidase-conjugated wheat-germ agglutinin. After disruption of the labelled intact cells, plasma-membrane purification could be monitored by ultrastructural examination of the various fractions for positive reaction product on the membrane vesicles.

scholarly journals Partial purification and characterization of oestrogen receptors in subfractions of hepatocyte plasma membranes

1980 ◽  
Vol 191 (3) ◽  
pp. 743-760 ◽  
Author(s):  
Richard J. Pietras ◽  
Clara M. Szego
Keyword(s):  
Plasma Membrane ◽  
Binding Sites ◽  
Wheat Germ Agglutinin ◽  
Wheat Germ ◽  
Plasma Membranes ◽  
Specific Binding ◽  
Low Density ◽  
Marker Enzymes ◽  
Low Density Plasma ◽  
Density Plasma

To assess the subcellular distribution of oestrogen-binding components in their native state, plasma membrane and other cell fractions were prepared from hepatocytes in the absence of [3H]oestradiol-17β. Cells from livers of ovariectomized rats were disrupted, with submaximal homogenization in buffered isotonic sucrose with CaCl2 and proteinase inhibitor, and fractionated by using isotonic media. Fractions were characterized by determinations of enzyme activities, biochemical constituents and ligand binding. Specific binding of 2nm-[3H]oestradiol-17β to intact cells and their fractions was detemined after equilibration for 1.5h at 4°C. More than 92% of the radioactivity from representative preparations was verified as authentic oestradiol by thin-layer chromatography. Activities of plasma-membrane marker enzymes as well as binding sites for oestrogen and for wheat germ agglutinin were present principally in particulate fractions, rather than in 105000g-supernatant fractions. However, by using alternative homogenization procedures (i.e. hypotonic media), known to fragment and strip structural components, oestradiol-binding sites and activities of plasma-membrane marker enzymes were distributed predominantly into cytosol. By using the more conservative procedures, plasma membranes of low (ρ=1.13–1.16) and high (ρ=1.16–1.18) density were purified from crude nuclear fractions. A second low-density subfraction of plasma membrane was prepared from microsome-rich fractions. Activities of plasma-membrane marker enzymes were enriched to about 28 and four times that of the homogenate in plasma membranes of low and high density respectively. Binding sites for wheat germ agglutinin and oestradiol were concentrated in low-density plasma membranes to 46–63 times that of the homogenate. Specific binding of oestrogen in low-density plasma membranes purified from crude nuclei was saturable, with an apparent association constant of 3.5nm. At saturation, such oestradiol receptors corresponded to 526fmol/mg of membrane protein. A Hill plot showed a moderate degree of positive co-operativity in the interaction of hormone with plasma membranes. Specific binding of [3H]oestradiol-17β was reduced by a 200-fold molar excess of unlabelled oestradiol-17β, oestriol or diethylstilbestrol, but not by oestradiol-17α, cortisol, testosterone or progesterone. Binding was also blocked by prior exposure of membranes to trypsin or to 60°C, but remained essentially undiminished by extraction of membranes with either hypotonic or high-salt buffers. Extraction with 0.1% (v/v) Triton X-100 partially solubilized the oestrogen-binding component(s) of plasma membranes. Particle-free extracts were resolved on 5–20% (w/v) sucrose density gradients with either 0.01m- or 0.4m-KCl, and the fractions were analysed by adsorption to hydroxyapatite. In low-salt gradients macromolecule-bound oestrogen sedimented at predominantly 7.4S and binding was 1560 times that of the homogenate. Under high-salt conditions oestradiol-binding activity occurred at both 3.6S and 4.9S.

scholarly journals Delayed restoration of Mg2+ content and transport in liver cells following ethanol withdrawal

2009 ◽  
Vol 297 (4) ◽  
pp. G621-G631 ◽  
Author(s):  
Lisa M. Torres ◽  
Christie Cefaratti ◽  
Liliana Berti-Mattera ◽  
Andrea Romani
Keyword(s):  
Plasma Membrane ◽  
Membrane Vesicles ◽  
Isolated Hepatocytes ◽  
Liver Cells ◽  
Ethanol Withdrawal ◽  
Adrenergic Stimulation ◽  
Plasma Membrane Vesicles ◽  
Isolated Cells ◽  
Intact Cells

Liver cells from rats chronically fed a Lieber-De Carli diet for 3 wk presented a marked decreased in tissue Mg2+ content and an inability to extrude Mg2+ into the extracellular compartment upon stimulation with catecholamine, isoproterenol, or cell-permeant cAMP analogs. This defect in Mg2+ extrusion was observed in both intact cells and purified liver plasma membrane vesicles. Inhibition of adrenergic or cAMP-mediated Mg2+ extrusion was also observed in freshly isolated hepatocytes from control rats incubated acutely in vitro with varying doses of ethanol (EtOH) for 8 min. In this model, however, the defect in Mg2+ extrusion was observed in intact cells but not in plasma membrane vesicles. In the chronic model, upon removal of EtOH from the diet hepatic Mg2+ content and extrusion required ∼10 days to return to normal level both in isolated cells and plasma membrane vesicles. In hepatocytes acutely treated with EtOH for 8 min, more than 60 min were necessary for Mg2+ content and extrusion to recover and return to the level observed in EtOH-untreated cells. Taken together, these data suggest that in the acute model the defect in Mg2+ extrusion is the result of a limited refilling of the cellular compartment(s) from which Mg2+ is mobilized upon adrenergic stimulation rather than a mere defect in adrenergic cellular signaling. The chronic EtOH model, instead, presents a transient but selective defect of the Mg2+ extrusion mechanisms in addition to the limited refilling of the cellular compartments.

scholarly journals Localization of axonally transported 125I-wheat germ agglutinin beneath the plasma membrane of chick retinal ganglion cells.

1983 ◽  
Vol 96 (2) ◽  
pp. 373-381 ◽  
Author(s):  
J H LaVail ◽  
I K Sugino ◽  
D M McDonald
Keyword(s):  
Plasma Membrane ◽  
Retinal Ganglion Cells ◽  
Optic Tectum ◽  
Wheat Germ Agglutinin ◽  
Wheat Germ ◽  
Plasma Membranes ◽  
Ganglion Cells ◽  
Retinal Ganglion ◽  
Electron Microscopic Autoradiography ◽  
Neuron Cell Body

The distribution of 125I-wheat germ agglutinin (WGA) transported by axons of chick retinal ganglion cells to layer d of the optic tectum was studied by electron microscopic autoradiography. We found that 52% of the radioactivity was located in axons and axon terminals in the contralateral optic tectum 22 h after intravitreal injection of affinity-purified 125I-WGA. Axons comprised 43% of the volume of layer d. Dendrites, glial cells, and neuron cell bodies contained 20%, 17%, and 3% of the label, whereas these structures comprised 24%, 21%, and 2% of the tissue volume, respectively. We also measured the distances between the autoradiographic silver grains and the plasma membranes of these profiles, and compared observed distributions of grains to theoretical distributions computed for band-shaped sources at various distances from the plasma membranes. This analysis revealed that the radioactive source within axons was distributed in a band of cytoplasm extending in from the plasma membrane a distance of 63 nm. Because WGA is known to bind to specific membrane glycoconjugates, we infer that at least some glycoconjugates may be concentrated within an annular region of cytoplasm just beneath the axonal plasma membrane after axoplasmic transport from the neuron cell body.

scholarly journals DETECTION OF PLASMA MEMBRANE CARBOHYDRATES WITH LECTIN PEROXIDASE CONJUGATES

1973 ◽  
Vol 59 (2) ◽  
pp. 436-443 ◽  
Author(s):  
Nicholas K. Gonatas ◽  
Stratis Avrameas
Keyword(s):  
Plasma Membrane ◽  
Horseradish Peroxidase ◽  
Cell Surface ◽  
Lymphoid Cell ◽  
Wheat Germ Agglutinin ◽  
Wheat Germ ◽  
Cell Interaction ◽  
Lymphoid Cells

With the use of the cytochemical stain for horseradish peroxidase of Graham and Karnovsky (1966. J. Histochem. Cytochem. 14:291), conjugates of horseradish peroxidase with ricin, wheat germ agglutinin, and phytohemagglutinin were employed for the morphologic demonstration of d-galactose (ricin), N-acetylglucosamine (wheat germ), and N-acetylgalactosamine (phytohemagglutinin) containing moieties on the surface of unfixed, or paraformaldehyde-fixed rat lymphoid cells. D-Galactose, or d-galactose containing disaccharides inhibited the interaction between ricin peroxidase and lymphoid cell surface; also, N-acetylglucosamine inhibited the wheat germ peroxidase-lymphoid cell interaction, but N-acetylgalactosamine failed to inhibit the reaction between phytohemagglutinin peroxidase and the surface of lymphoid cells.

scholarly journals Maltose/proton co-transport in Saccharomyces cerevisiae. Comparative study with cells and plasma membrane vesicles

1992 ◽  
Vol 284 (2) ◽  
pp. 441-445 ◽  
Author(s):  
C C M Van Leeuwen ◽  
R A Weusthuis ◽  
E Postma ◽  
P J A Van den Broek ◽  
J P Van Dijken
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Plasma Membrane ◽  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Plasma Membranes ◽  
Membrane Vesicles ◽  
Proton Motive Force ◽  
Plasma Membrane Vesicles ◽  
Intact Cells ◽  
Maltose Transport

Maltose/proton co-transport was studied in intact cells and in plasma membrane vesicles of the yeast Saccharomyces cerevisiae. In order to determine uphill transport in vesicles, plasma membranes were fused with proteoliposomes containing cytochrome c oxidase as a proton-motive force-generating system. Maltose accumulation, dependent on the electrical and pH gradients, was observed. The initial uptake velocity and accumulation ratio in vesicles proved to be dependent on the external pH. Moreover, kinetic analysis of maltose transport showed that Vmax. values greatly decreased with increasing pH, whereas the Km remained virtually constant. These observations were in good agreement with results obtained with intact cells, and suggest that proton binding to the carrier proceeds with an apparent pK of 5.7. The observation with intact cells that maltose is co-transported with protons in a one-to-one stoichiometry was ascertained in the vesicle system by measuring the balance between proton-motive force and the chemical maltose gradient. These results show that maltose transport in vesicles prepared by fusion of plasma membranes with cytochrome c oxidase proteoliposomes behaves in a similar way as in intact cells. It is therefore concluded that this vesicle model system offers a wide range of new possibilities for the study of maltose/proton co-transport in more detail.

scholarly journals Mechanical properties of plasma membrane vesicles correlate with lipid order, viscosity and cell density

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Jan Steinkühler ◽  
Erdinc Sezgin ◽  
Iztok Urbančič ◽  
Christian Eggeling ◽  
Rumiana Dimova
Keyword(s):  
Mechanical Properties ◽  
Plasma Membrane ◽  
Cell Density ◽  
Plasma Membranes ◽  
Membrane Vesicles ◽  
Energetic Cost ◽  
Cholesterol Depletion ◽  
Bending Rigidity ◽  
Plasma Membrane Vesicles ◽  
Intact Cells

Abstract Regulation of plasma membrane curvature and composition governs essential cellular processes. The material property of bending rigidity describes the energetic cost of membrane deformations and depends on the plasma membrane molecular composition. Because of compositional fluctuations and active processes, it is challenging to measure it in intact cells. Here, we study the plasma membrane using giant plasma membrane vesicles (GPMVs), which largely preserve the plasma membrane lipidome and proteome. We show that the bending rigidity of plasma membranes under varied conditions is correlated to readout from environment-sensitive dyes, which are indicative of membrane order and microviscosity. This correlation holds across different cell lines, upon cholesterol depletion or enrichment of the plasma membrane, and variations in cell density. Thus, polarity- and viscosity-sensitive probes represent a promising indicator of membrane mechanical properties. Additionally, our results allow for identifying synthetic membranes with a few well defined lipids as optimal plasma membrane mimetics.

Pore-Spanning Plasma Membranes Derived from Giant Plasma Membrane Vesicles

2021 ◽  
Author(s):  
Nikolas K. Teiwes ◽  
Ingo Mey ◽  
Phila C. Baumann ◽  
Lena Strieker ◽  
Ulla Unkelbach ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Plasma Membranes ◽  
Membrane Vesicles ◽  
Plasma Membrane Vesicles

scholarly journals Resolution of diaminobenzidine for the detection of horseradish peroxidase on surfaces of cultured cells.

1985 ◽  
Vol 33 (8) ◽  
pp. 837-839 ◽  
Author(s):  
A Messing ◽  
A Stieber ◽  
N K Gonatas
Keyword(s):  
Plasma Membrane ◽  
Horseradish Peroxidase ◽  
Plasma Membranes ◽  
Cultured Cells ◽  
Lateral Spread ◽  
Ciliary Ganglion ◽  
Monolayer Cultures ◽  
Indirect Immunoperoxidase ◽  
Ciliary Ganglion Neurons ◽  
Ganglion Neurons

The resolution of indirect immunoperoxidase methods for localizing antigens on the surface of plasma membranes of cultured cells was tested using dissociated monolayer cultures of ciliary ganglion neurons prelabeled with cationic ferritin. Clusters of ferritin were produced on the cell surface by warming the cells to 37 degrees C after the ferritin, rabbit anti-ferritin, and goat anti-rabbit immunoglobulin coupled to horseradish peroxidase had all been applied. Intense 3,3'-diaminobenzidine tetrahydrochloride (DAB) staining was limited to the regions immediately surrounding the ferritin clusters. The lateral spread of the DAB reaction product beyond the outer ferritin particles in each cluster averaged 54-81 nm in four experiments. A second type of increased density, coinciding with the thickness of the plasma membrane, was also seen. These stained plasma membranes extended 161-339 nm from the ferritin clusters.

scholarly journals Development of an aqueous-space mixing assay for fusion of granules and plasma membranes from human neutrophils

1996 ◽  
Vol 314 (2) ◽  
pp. 469-475 ◽  
Author(s):  
R. Alexander BLACKWOOD ◽  
James E. SMOLEN ◽  
Ronald J. HESSLER ◽  
Donna M. HARSH ◽  
Amy TRANSUE
Keyword(s):  
Plasma Membrane ◽  
Plasma Membranes ◽  
Membrane Vesicles ◽  
Phospholipid Vesicle ◽  
Human Neutrophils ◽  
Plasma Membrane Vesicles ◽  
Fluorescent Marker ◽  
Whole Cells ◽  
Specific Granules ◽  
Neutrophil Degranulation

Several models have been developed to study neutrophil degranulation. At the most basic level, phospholipid vesicles have been used to investigate the lipid interactions occurring during membrane fusion. The two major forms of assays used to measure phospholipid vesicle fusion are based either on the dilution of tagged phospholipids within the membrane of the two fusing partners or the mixing of the aqueous contents of the vesicles. Although problems exist with both methods, the latter is considered to be more accurate and representative of true fusion. Using 8-aminonaphthalene-1,3,6-trisulphonic acid (ANTS) as a fluorescent marker, we have taken advantage of the quenching properties of p-xylenebispyridinium bromide (‘DPX’) to develop a simple aqueous-space mixing assay that can be used with any sealed vesicle. We compared our new assay with more conventional assays using liposomes composed of phosphatidic acid (PA) and phosphatidylethanolamine (PE), obtaining comparable results with respect to Ca2+-dependent fusion. We extended our studies to measure the fusion of neutrophil plasma-membrane vesicles as well as azurophil and specific granules with PA/PE (1:3) liposomes. Both specific granules and plasma-membrane vesicles fused with PA/PE liposomes at [Ca2+] as low as 500 μM, while azurophil granules showed no fusion at [Ca2+] as high as 12 mM. These differences in the ability of Ca2+ to induce fusion may be related to differences observed in whole cells with respect to secretion.

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