scholarly journals Are polyphosphoinositides associated with glycophorin in human erythrocyte membranes?

1979 ◽  
Vol 179 (2) ◽  
pp. 441-444 ◽  
Author(s):  
S D Shukla ◽  
R Coleman ◽  
J B Finean ◽  
R H Michell
Keyword(s):  
Erythrocyte Membrane ◽  
Human Erythrocyte ◽  
Erythrocyte Membranes ◽  
Human Erythrocyte Membrane ◽  
Human Erythrocyte Membranes ◽  
Partition Method ◽  
Triton X

Glycophorin prepared by a lithium di-iodosalicylate-extraction/phenol-partition method was rich in polyphosphoinositides (phosphatidyl-myo-inositol 4-phosphate and phosphatidyl-myo-inositol 4,5-bisphosphate), but glycophorin extracted by Triton X-100 showed no such enrichment. The enrichment observed in the former preparations appeared not to be caused by pre-existing association between glycophorin and polyphosphoinositides in the human erythrocyte membrane, but to be largely a consequence of the preparative procedures.

scholarly journals Electron microscope study of reassociation of spectrin and actin with the human erythrocyte membrane

1981 ◽  
Vol 90 (1) ◽  
pp. 70-77 ◽  
Author(s):  
S Tsukita ◽  
S Tsukita ◽  
H Ishikawa ◽  
S Sato ◽  
M Nakao
Keyword(s):  
Erythrocyte Membrane ◽  
Human Erythrocyte ◽  
Actin Filaments ◽  
Actin Polymerization ◽  
Erythrocyte Membranes ◽  
Human Erythrocyte Membrane ◽  
Thin Sections ◽  
Fixation Treatment ◽  
Human Erythrocyte Membranes ◽  
Inside Out

Reassociation of spectrin and actin with human erythrocyte membranes was studied by stereoscopic electron microscopy of thin sections combined with tannic acid- glutaraldehyde fixation. Treatment of the erythrocyte membrane with 0.1 mM EDTA (pH 8.0) extracted more than 90 percent of the spectrin and actin and concomitantly removed filamentous meshworks underlying the membranes, followed by fragmentation into small inside-out vesicles. When such spectrin-depleted vesicles were incubated with the EDTA extract (crude spectrin), a filamentous meshwork, similar to those of the original membranes, was reformed on the cytoplasmic surface of the vesicles. The filamentous components, with a uniform thickness of 9 nm, took a tortuous course and joined one another often in an end-to-end fashion to form a irregular but continuous meshwork parallel to the membrane. Purified spectrin was also reassociated with the vesicles in a population density of filamentous components almost comparable to that of the crude spectrin-reassociated vesicles. However, the meshwork formation was much smaller in extent, showing many independent filamentous components closely applied to the vesicle surface. When muscle G-actin was added to the crude spectrin- or purified spectrin- reassociated vesicles under conditions which favor actin polymerization, actin filaments were seen to attach to the vesicles through the filamentous components. Two modes of association of actin filaments with the membrane were seen: end-to-membrane and side-to- membrane associations. In the end-to-membrane association, each actin filament was bound with several filamentous components exhibiting a spiderlike configuration, which was considered to be the unit of the filamentous meshwork of the original erythrocyte membrane.

scholarly journals Ultrastructure of the intact skeleton of the human erythrocyte membrane.

1986 ◽  
Vol 102 (3) ◽  
pp. 997-1006 ◽  
Author(s):  
B W Shen ◽  
R Josephs ◽  
T L Steck
Keyword(s):  
Human Erythrocyte ◽  
Actin Filaments ◽  
Band 3 ◽  
Carbon Films ◽  
Erythrocyte Membranes ◽  
Accessory Proteins ◽  
Red Cell Membrane ◽  
Human Erythrocyte Membranes ◽  
Low Ionic Strength ◽  
Triton X

Filamentous skeletons were liberated from isolated human erythrocyte membranes in Triton X-100, spread on fenestrated carbon films, negatively stained, and viewed intact and unfixed in the transmission electron microscope. Two forms of the skeleton were examined: (a) basic skeletons, stripped of accessory proteins with 1.5 M NaCl so that they contain predominantly polypeptide bands 1, 2, 4.1, and 5; and (b) unstripped skeletons, which also bore accessory proteins such as ankyrin and band 3 and small plaques of residual lipid. Freshly prepared skeletons were highly condensed. Incubation at low ionic strength and in the presence of dithiothreitol for an hour or more caused an expansion of the skeletons, which greatly increased the visibility of their elements. The expansion may reflect the opening of spectrin from a compact to an elongated disposition. Expanded skeletons appeared to be organized as networks of short actin filaments joined by multiple (5-8) spectrin tetramers. In unstripped preparations, globular masses were observed near the centers of the spectrin filaments, probably corresponding to complexes of ankyrin with band 3 oligomers. Some of these globules linked pairs of spectrin filaments. Skeletons prepared with a minimum of perturbation had thickened actin protofilaments, presumably reflecting the presence of accessory proteins. The length of these actin filaments was highly uniform, averaging 33 +/- 5 nm. This is the length of nonmuscle tropomyosin. Since there is almost enough tropomyosin present to saturate the F-actin, our data support the hypothesis that tropomyosin may determine the length of actin protofilaments in the red cell membrane.

scholarly journals Membrane glycopeptides from old and young human erythrocytes (Short Communication)

1974 ◽  
Vol 140 (3) ◽  
pp. 557-560 ◽  
Author(s):  
Cesare Balduini ◽  
Carlo Luigi Balduini ◽  
Edoardo Ascari
Keyword(s):  
Sialic Acid ◽  
Erythrocyte Membrane ◽  
Human Erythrocyte ◽  
Short Communication ◽  
Chemical Characterization ◽  
Erythrocyte Membranes ◽  
Main Peak ◽  
Human Erythrocyte Membranes ◽  
Papain Digestion

Glycopeptides were extracted by papain digestion from old and young human erythrocyte membranes and fractionated on DEAE-Sephadex A-25. Chemical characterization of the unfractionated samples and of the main peak eluted from the column indicates that glycoproteins of the erythrocyte membrane undergo significant decreases in sialic acid and galactosamine content with aging.

scholarly journals Solubilization of human erythrocyte membrane glycoproteins by triton X-100

1979 ◽  
Vol 179 (2) ◽  
pp. 299-303 ◽  
Author(s):  
R S Pratt ◽  
G M Cook
Keyword(s):  
Sialic Acid ◽  
Erythrocyte Membrane ◽  
Human Erythrocyte ◽  
General Procedure ◽  
Membrane Glycoprotein ◽  
Membrane Glycoproteins ◽  
Human Erythrocyte Membrane ◽  
Ionic Detergent ◽  
Triton X ◽  
Mild Solubilization

1. The enzymic removal of sialic acid residues from the glycoproteins of the human erythrocyte decreases the solubilization of membrane glycoprotein by Triton X-100. 2. The solubilization of asialoglycoprotein by Triton X-100 may be restored by the addition of borate. 3. Use of this non-ionic detergent in the presence of borate, as a general procedure for the mild solubilization of membrane glycoproteins deficient in sialic acid residues, is discussed.

scholarly journals Phosphotyrosine phosphatase associated with band 3 protein in the human erythrocyte membrane

1996 ◽  
Vol 314 (3) ◽  
pp. 881-887 ◽  
Author(s):  
Yehudit ZIPSER ◽  
Nechama S. KOSOWER
Keyword(s):  
Erythrocyte Membrane ◽  
Human Erythrocyte ◽  
Intact Cell ◽  
Band 3 ◽  
Band 3 Protein ◽  
Human Erythrocyte Membrane ◽  
Major Fraction ◽  
Phosphotyrosine Phosphatase ◽  
A Minor ◽  
Triton X

The anion-exchange band 3 protein is the main erythrocyte protein that is phosphorylated by tyrosine kinase. To study the regulation of band 3 phosphorylation, we examined phosphotyrosine phosphatase (PTP) activity in the human erythrocyte. We show that the human erythrocyte membrane contains a band 3-associated neutral PTP which is activated by Mg2+ and inhibited by Mn2+ and vanadate. The PTP is active in the intact cell and in the isolated membrane. A major fraction of the PTP is tightly bound to the membrane and can be extracted from it by Triton X-100; a minor part is associated with the Triton X-100-insoluble cytoskeleton. The behaviour of the PTP parallels that of band 3, the major fraction of which is extractable by detergents with a minor fraction being anchored to the cytoskeleton. Moreover, band 3 is co-precipitated when the PTP is immunoprecipitated from solubilized membranes, and PTP is co-precipitated when band 3 is immunoprecipitated. The PTP appears to be related to PTP1B (identified using an antibody to an epitope in its catalytic domain and by molecular mass). The system described here has a unique advantage for PTP research, since it allows the study of the interaction of a PTP with an endogenous physiological substrate that is present in substantial amounts in the cell membrane. The membrane-bound, band 3-associated, PTP may play a role in band 3 function in the erythrocyte and in other cells which have proteins analogous to band 3.

The inhibitory effects of polyoxyethylene detergents on human erythrocyte acetylcholinesterase and Ca2+ + Mg2+ ATPase

1989 ◽  
Vol 67 (2-3) ◽  
pp. 137-146 ◽  
Author(s):  
R. Blaine Moore ◽  
J. F. Manery ◽  
J. Still ◽  
V. N. Mankad
Keyword(s):  
Human Erythrocyte ◽  
Acetylcholinesterase Activity ◽  
Significant Inhibition ◽  
Erythrocyte Membranes ◽  
Head Group ◽  
Polar Head Group ◽  
Detergent Concentration ◽  
Human Erythrocyte Membranes ◽  
Hydrophobic Tail ◽  
Triton X

The activities of acetylcholinesterase and Ca2+ + Mg2+ ATPase were measured following treatment of human erythrocyte membranes with nonsolubilizing and solubilizing concentrations of Triton X-100. A concentration of 0.1% (v/v) Triton X-100 caused a significant inhibition of both enzymes. The inhibition appears to be caused by perturbations in the membrane induced by Triton X-100 incorporation. No acetylcholinesterase activity and little Ca2+ + Mg2+ ATPase activity were detected in the supernatant at 0.05% Triton X-100 although this same detergent concentration induced changes in the turbidity of the membrane suspension. Also, no inhibition of soluble acetylcholinesterase was observed over the entire detergent concentration range. The inhibition of these enzymes at 0.1% Triton X-100 was present over an eightfold range of membrane protein in the assay indicating an independence of the protein/detergent ratio. The losses in activities of these two enzymes could be prevented by either including phosphatidylserine in the Triton X-100 suspension or using Brij 96 which has the same polyoxyethylene polar head group but an oleyl hydrophobic tail instead of the p-tert-octylphenol group of Triton X-100. The results are discussed in regard to the differential recovery of enzyme activities over the entire detergent concentration range.Key words: Triton X-100, erythrocyte membranes, acetylcholinesterase, Ca2+ + Mg2+ ATPase, polyoxyethylene detergents.

Coisolation of glycophorin A and polyphosphoinositides from human erythrocyte membranes

1978 ◽  
Vol 56 (5) ◽  
pp. 349-351 ◽  
Author(s):  
J. Thomas Buckley
Keyword(s):  
Membrane Protein ◽  
Erythrocyte Membrane ◽  
Lipid Composition ◽  
Human Erythrocyte ◽  
Erythrocyte Membranes ◽  
Glycophorin A ◽  
Firm Conclusion ◽  
Membrane Phospholipids ◽  
Human Erythrocyte Membranes ◽  
Significant Enrichment

The lipid composition of purified erythrocyte membrane glycophorin was measured. Diphosphoinositide, triphosphoinositide, and phosphatidylserine are the major phospholipids in glycophorin preparations. Nearly all of the radioactive diphosphoinositide and triphosphoinositide extracted from erythrocyte membranes by lithium diiodosalicylate are recovered in purified glycophorin. There appeared to be no significant enrichment of other acidic membrane phospholipids in the protein. The results do not permit a firm conclusion as to whether the polyphosphoinositides are associated specifically with the membrane protein or whether fortuitous binding has occurred during purification.

Proteins of Marsupial Erythrocyte Membranes

1985 ◽  
Vol 38 (1) ◽  
pp. 121 ◽  
Author(s):  
GB Ralston
Keyword(s):  
Erythrocyte Membrane ◽  
Human Erythrocyte ◽  
Sodium Dodecyl ◽  
Tammar Wallaby ◽  
Erythrocyte Membranes ◽  
Blue Staining ◽  
Human Erythrocyte Membrane ◽  
Coomassie Blue Staining ◽  
Red Kangaroo ◽  
Western Grey Kangaroo

The proteins of erythrocyte membranes from the red kangaroo, western grey kangaroo, eastern grey wallaroo (euro), red-necked wallaby, Tammar wallaby, and brush-tail possum have been fractionated on acrylamide gels in the presence of sodium dodecyl sulfate. The pattern of proteins was remarkably similar between the different marsupial species. The pattern of Coomassie blue-staining proteins in the membranes of these species was also very similar to that of the human erythrocyte membrane. However, the glycoproteins in the marsupial erythrocyte membranes were markedly less conspicuous than those of the human erythrocyte membrane. Furthermore, the mobilities of the glycoproteins from the marsupials were different from those of the human erythrocyte membrane.

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