Influence of biotin on the lipid composition of plasma membranes from Hypomyces chlorinus

1990 ◽  
Vol 68 (1) ◽  
pp. 138-144
Author(s):  
J.-M. Touze-Soulet ◽  
J. D. Weete ◽  
M. Sancholle ◽  
J. Rami ◽  
R. Dargent
Keyword(s):  
Plasma Membrane ◽  
Plasma Membranes ◽  
Polymer System ◽  
Phospholipid Content ◽  
Biotin Deficiency ◽  
Two Phase ◽  
Molar Ratios ◽  
Microsomal Membranes ◽  
Enzyme Markers ◽  
Induced Aggregation

Subfractions of microsomal membranes from the biotin heteroauxotroph Hypomyces chlorinus Tul., cultured in media containing optimal or suboptimal levels of the vitamin, were isolated using a two-phase polymer system and characterized as plasma membrane-enriched on the basis of absence of Zn2+-induced aggregation, enrichment of appropriate enzyme markers, and phosphotungstic acid – chromic acid staining. The protein/lipid ratio of membranes from the biotin-sufficient and -deficient cultures was 2; the phospholipid content was 126 and 181 μg/mg protein; and the sterol/phospholipid molar ratios were 0.38 and 0.16, respectively, with ergosterol as the predominant sterol. The lipids were qualitatively similar in the plasma membrane fractions from the two treatments. Ergosterol content of the membrane fractions from mycelium cultured in low biotin medium was 40–100% less than that from the corresponding biotin-sufficient cultures. A nonphosphorus glycolipid was the predominant lipid of the plasma membranes from both treatments.Key words: Hypomyces, plasma membrane, sterols, biotin deficiency, ergosterol.

scholarly journals A species-non-specific liver plasma-membrane antigen and its involvement in chronic active hepatitis

1980 ◽  
Vol 186 (3) ◽  
pp. 679-685 ◽  
Author(s):  
T A De Kretser ◽  
I G McFarlane ◽  
A L Eddleston ◽  
R Williams
Keyword(s):  
Plasma Membrane ◽  
Chronic Active Hepatitis ◽  
Plasma Membranes ◽  
Specific Antigen ◽  
Polymer System ◽  
Two Phase ◽  
Normal Human Liver ◽  
Normal Human ◽  
Electron Microscopical ◽  
Liver Specific Lipoprotein

Rabbit liver plasma membranes were isolated and purified by using an aqueous two-phase polymer system. Examination of these preparations with respect to electron-microscopical appearance, distribution of marker enzymes and gross biochemical composition revealed them to be free from contamination by intracellular components. Sera from ten patients with chronic active hepatitis, four with and six without hepatitis B viral markers (HBsAg) in their sera, produced a single precipitin line on immunodiffusion against a detergent extract of the isolated plasma membranes. Sera from HBsAg-positive and HBsAg-negative patients reacted against the same antigen. This antigen was enriched in the plasma membrane preparations compared with whole-liver homogenates and was identical with a species-non-specific antigen in a macromolecular fraction of normal human liver, which has been previously described as liver-specific lipoprotein.

The Isolation and Characterization of the Plasma Membrane of Cultured Chinese Hamster Ovary Cells

1975 ◽  
Vol 53 (8) ◽  
pp. 914-920 ◽  
Author(s):  
R. L. Juliano ◽  
E. Gagalang
Keyword(s):  
Plasma Membrane ◽  
Chinese Hamster Ovary ◽  
Plasma Membranes ◽  
Chinese Hamster Ovary Cells ◽  
Polymer System ◽  
Chinese Hamster ◽  
Two Phase ◽  
Ovary Cells ◽  
Isolation And Characterization ◽  
Chemical Assay

Plasma membranes were prepared from cultured Chinese hamster ovary cells utilizing a two-phase polymer system and were characterized by enzymatic and chemical assay, and by electron microscopy. The usual degree of purification of presumptive membrane markers such as Na+–K+ ATPase (ATP phosphohydrolase, EC 3.6.1.3) ranged from three-to eightfold. Gel electrophoresis in SDS revealed several polypeptides and two glycopeptides which were enriched in the plasma membrane fraction.

scholarly journals Comparative studies on the soluble and plasma membrane associated nitrate reductase from Cucumis sativus L.

2014 ◽  
Vol 63 (3-4) ◽  
pp. 309-314 ◽  
Author(s):  
Grażyna Kłobus ◽  
Jolanta Marciniak ◽  
Józef Buczek
Keyword(s):  
Plasma Membrane ◽  
Nitrate Reductase ◽  
Plasma Membranes ◽  
Polyclonal Antiserum ◽  
Soluble Form ◽  
Phase System ◽  
Two Phase ◽  
Cucumis Sativus L ◽  
Cucumber Roots ◽  
Biochemical Comparison

The biochemical comparison between two forms of nitrate reductase from cucumber roots: the soluble enzyme and the plasma membrane-associated one was made. Soluble nitrate reductase was purified on the blue-Sepharose 4B. The nitrate reductase bound with plasma membranes was isolated from cucumber roots by partition of microsomes in the 6.5% dextran-PEG two phase system. The molecular weight of native enzyme estimated with HPLC was 240 kDa and 114 kDa for the soluble and membrane bounded enzyme, respectively. Temperature induced phase separation in Triton X-114 indicated a huge difference in hydrophobicity of the plasma membrane associated nitrate reductase and soluble form of enzyme. Small differences were observed in partial activities of plasma membrane nitrate reductase and soluble nitrate reductase. Also experiments with polyclonal antiserum raised against the native nitrate reductase showed some differences in the immunological properties of both forms of the nitrate reductase. The above results indicated that in cucumber roots two different forms of the nitrate reductase are present.

Chloroacetamides Affect the Plasma Membrane

2002 ◽  
Vol 57 (9-10) ◽  
pp. 843-852 ◽  
Author(s):  
Bernd Matthes ◽  
Peter Böger
Keyword(s):  
Fatty Acids ◽  
Plasma Membrane ◽  
Fatty Acid ◽  
De Novo ◽  
Fatty Acid Content ◽  
Direct Consequence ◽  
Two Phase ◽  
Phase Partitioning ◽  
Microsomal Membranes ◽  
And Function

In the present study membrane fatty acids were analyzed to find a link between the biosynthesis inhibition of very-long-chain fatty acids and the phytotoxic effects of herbicidal chloroacetamides. Accordingly,we have isolated membranes of cucumber seedlings (Cucumis sativus) by two-phase partitioning and analyzed their fatty acid content. Saturated VLCFAs ranging from C20 to C26 were found in high amounts (22%) in the plasma membrane fraction. Nonmodified VLCFAs were predominantly present in phospholipids, while saturated 2-hydroxylated VLCFAs were identified in cerebrosides. Treatment of intact seedlings with chloroacetamides markedly reduced the VLCFA content in the plasma membrane. This result could be specified by fatty-acid labeling using [14C]malonate as a substrate for fatty acid elongation. De novo incorporation of VLCFAs into the plasma membrane and into microsomal membranes, respectively, was severely impaired by chloroacetamides with I50 values between 10 to 100 nm. These results confirm the previous finding that chloroacetamides inhibit VLCFA biosynthesis localized in the microsomes (Böger et al., Pest Manage. Sci. 56, 497D508, 2000). The direct consequence of this inhibition is a strong decrease of VLCFAs required as constituents of the plasma membrane and the substitution by shorter acyl chains. Apparently, physical properties and function of the plasma membrane are affected eventually leading to death of the plant.

Changes in protein composition in cellular membranes of various parts of secondary dormant cucumber seeds treated with ethanol

2000 ◽  
Vol 10 (1) ◽  
pp. 61-70 ◽  
Author(s):  
Y. Sreenivasulu ◽  
Dilip Amritphale
Keyword(s):  
Plasma Membrane ◽  
Membrane Proteins ◽  
Time Course ◽  
Plasma Membranes ◽  
Protein Composition ◽  
Cellular Membrane ◽  
Embryonic Axis ◽  
Dormancy Breaking ◽  
Cucumis Sativus L ◽  
Microsomal Membranes

AbstractSecondary seed dormancy in cucumber (Cucumis sativus L.) cv.Poinsett 76 could be broken with ethanol. Breakage of dormancy was accompanied by significant changes in the composition of membrane proteins in various seed parts. Compared to the intracellular membranes, a change in the protein composition of plasma membranes from the embryonic axis and cotyledons was evident early in the time-course of ethanol-induced germination of dormant seeds. While few alterations in the membrane protein composition in response to ethanol treatment occurred both in dormant and nondormant seeds, a number of changes occurred exclusively in ethanol-treated dormant seeds. Notably, a 14 kD protein in the plasma membrane from the embryonic axis and a 35 kD protein in the microsomal membranes from the perisperm-endosperm envelope disappeared in the ethanol-treated dormant seeds, but not in the ethanol-treated nondormant seeds. Also marked decrease in the content of a 23 kD protein in the plasma membrane from the cotyledons was observed in ethanol-treated dormant seeds only. It is suggested that the particular changes in cellular membrane proteins, which occurred in ethanol-treated dormant seeds much before the first visible indication of germination, might be related to dormancy breaking rather than to the germination process.

scholarly journals Plasma Membrane from Muskmelon Leaves: Purification and Lipid Composition during Growth at 15 or 30C

1990 ◽  
Vol 115 (2) ◽  
pp. 274-277 ◽  
Author(s):  
Gene Lester
Keyword(s):  
Plasma Membrane ◽  
Plasma Membranes ◽  
Total Phospholipid ◽  
Total Sterol ◽  
Sucrose Density Gradient ◽  
Marker Enzyme ◽  
Two Phase ◽  
Aqueous Polymer ◽  
Phospholipid Ratio ◽  
Partitioning Procedure

Using an aqueous polymer two-phase [polyethylene glycol (PEG) 3400/dextran T500, 6.2%: 6.2%, w/w] partitioning procedure combined with isopycnic fractionation, plasma membranes derived from muskmelon (Cucumis melo L. var. reticulates Naud.) leaf blades have been isolated and examined for marker enzyme activity, density, and molecular composition. After aqueous polymer partitioning, plasma membranes were centrifuged on a linear sucrose density gradient, and a single band was found at the 31% (w/w) sucrose (1.13 g-cm-3). Identification of plasma membranes was performed by the combination of K+-stimulated ATPase, pH 6.5, vanadate inhibition of ATPase and KNO3-insensitive ATPase activity. Plasma membranes from seedling leaves grown for 5 days at 15C had the highest concentration of total phospholipids, the lowest concentration of proteins, and a total sterol concentration not significantly different from leaves grown at 30C. The total sterol to total phospholipid ratio of the plasma membrane from leaves grown for 5 days at 15C was ≈1:1; from leaves grown for 10 days at 15C or 5 days at 30C the ratio was ≈2:1; and from leaves grown for 10 days at 30C the ratio was ≈3:1. The plasma membrane phospholipid saturated to unsaturated fatty acid ratio from leaves grown for 5 days at 15C was ≈0.8:1.0; from leaves grown for 10 days at 15C or 5 days at 30C the ratio was ≈1.0:1.0; and from leaves grown for 10 days at 30C it was 1.4:1.0.

Plasma membranes from Physarum polycephalum Plasmodia: purification, characterization, and comparison with amoebae plasma membranes

1984 ◽  
Vol 62 (9) ◽  
pp. 831-836 ◽  
Author(s):  
Dominick Pallotta ◽  
Anne Barden ◽  
Rémi Martel ◽  
Josée Kirouac-Brunet ◽  
François Bernier ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Membrane Proteins ◽  
Gel Electrophoresis ◽  
Membrane Fraction ◽  
Physarum Polycephalum ◽  
Sucrose Gradient ◽  
Plasma Membranes ◽  
Two Dimensional ◽  
Two Phase ◽  
Crude Membrane Fraction

Two methods are described for preparing plasma membranes from Physarum polycephalum plasmodia. In the first method Plasmodia were broken in homogenizing medium (250 mM sucrose, 1 mM ZnCl2, 10 mM Tris (pH 8.0)), and the nuclei were removed by low speed centrifugation. A crude membrane fraction was collected and the membranes were purified by centrifugation in a linear 30–65% (w/w) sucrose gradient. The membranes sedimented in a single band at a density of 1.26 g/cm3. In the second method the plasmodia were broken in the same homogenizing medium and a crude membrane fraction was prepared by differential centrifugation. The membranes were purified by the Dextran – polyethylene glycol aqueous two-phase system. Membranes from both preparations were found by enzymatic assay and by electron microscopy to be virtually free of contaminating cell organelles. Analyses by one- and two-dimensional polyacrylamide gel electrophoresis showed a great similarity in the proteins from two-phase and sucrose gradient prepared membranes, indicating that either technique can be used to prepare membranes for protein studies. An analysis by two-dimensional gel electrophoresis of plasma membrane proteins from amoebae and plasmodia showed differences in some of the major proteins, indicating that changes occur in plasma membrane proteins during differentiation.

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