scholarly journals INTRAMEMBRANE PARTICLE AGGREGATION IN ERYTHROCYTE GHOSTS

1974 ◽  
Vol 63 (3) ◽  
pp. 1018-1030 ◽  
Author(s):  
Arnljot Elgsaeter ◽  
Daniel Branton

We have used freeze-etching and SDS-polyacrylamide gel electrophoresis to study the conditions under which the intramembrane particles of the human erythrocyte ghost may be aggregated. The fibrous membrane protein, spectrin, can be almost entirely removed from erythrocyte ghosts with little or no change in the distribution of the particles. However, after spectrin depletion, particle aggregation in the plane of the membrane may be induced by conditions which cause little aggregation in freshly prepared ghosts. This suggests that the spectrin molecules form a molecular meshwork which limits the translational mobility of the erythrocyte membrane particles.

1971 ◽  
Vol 49 (3) ◽  
pp. 337-347 ◽  
Author(s):  
F. B. St. C. Palmer ◽  
J. A. Verpoorte

Membrane protein preparations were obtained by n-butanol extraction of salt-free aqueous suspensions of human erythrocyte ghosts. The solubilized protein contained 4.5% carbohydrate, including glucosamine and galactosamine, 1.7% sialic acid, and 0.2% phosphorus. Gel electrophoresis indicated the presence of a large number of proteins in the solubilized fraction. Of the phosphorus present 15% could be extracted with chloroform–methanol (2/1) and was shown to consist of phosphatidylserine and some phosphatidylinositol. A further 65% of the phosphorus was extracted with chloroform–methanol–HCl (200/100/1) and this extract was shown to consist principally of diphosphoinositide and triphosphoinositide. The remaining protein-bound phosphorus, representing 0.03% of the protein, could not be separated from the protein. Following treatment with the organic solvents the protein was resolubilized. The carbohydrate and sialic acid concentrations and the gel electrophoretic pattern were not altered. Following incubation of erythrocytes with inorganic 32P, the polyphosphoinositides were rapidly labelled. The phosphoprotein was also rapidly labelled but to a lesser extent. The phosphatidylinositol and phosphatidylserine were very poorly labelled.


Blood ◽  
1984 ◽  
Vol 64 (3) ◽  
pp. 599-606 ◽  
Author(s):  
MJ Telen ◽  
TJ Palker ◽  
BF Haynes

Abstract We have previously shown that a murine monoclonal antibody (A3D8) identifies a human erythrocyte protein antigen whose expression is regulated by the Lutheran inhibitor [In(Lu)] gene. In the present study, we demonstrated by immunoprecipitation and Western blot techniques that the antigen defined by A3D8 was on an 80-kD erythrocyte membrane protein. A second 170-kD protein was coprecipitated with the 80-kD protein but failed to show antigen activity by Western blot analysis. The 170-kD protein, when analyzed by sodium dodecyl sulfate- polyacrylamide gel electrophoresis in two dimensions, was composed of 50- and 30-kD disulfide-linked subunits. In(Lu) Lu[a-b-) erythrocytes differed from Lu(a+b+) or Lu(a-b+) erythrocytes in that In(Lu) deoxycholate erythrocyte membrane extracts contained trace amounts of immunoprecipitable 80-kD protein compared with detergent-solubilized erythrocyte membrane extracts prepared from Lu(a+b+) or Lu(a-b+) subjects.


1987 ◽  
Vol 244 (1) ◽  
pp. 123-128 ◽  
Author(s):  
M E Reid ◽  
D J Anstee ◽  
M J A Tanner ◽  
K Ridgwell ◽  
G T Nurse

The human erythrocyte membrane sialoglycoproteins beta and gamma are important for the maintenance of the discoid shape of the normal erythrocyte. In this paper we show that the human erythrocyte sialoglycoproteins beta and gamma (hereafter called beta and gamma) are structurally related. Rabbit antisera produced against purified beta and beta 1 and rendered specific to the cytoplasmic portion of these proteins also react with the cytoplasmic portion of gamma. Some human anti-Gerbich (Ge) sera react with the extracellular portion of both beta and gamma. This reactivity is shown to be directed towards a common epitope on beta and gamma. However, most anti-Ge sera do not react with beta, but react with an extracellular epitope only present on gamma. All individuals who lack the Ge antigens lack beta and gamma. In some cases abnormal sialoglycoproteins are present in the erythrocytes, and these are shown to be structurally related to beta and gamma. Rabbit antisera raised against the purified abnormal sialoglycoprotein from a Ge-negative erythrocyte type reacted with the cytoplasmic portion of both beta and gamma. Unlike normal beta and gamma, the abnormal sialoglycoproteins found in Ge-negative erythrocytes migrate as a diffuse band on SDS/polyacrylamide-gel electrophoresis. Studies using endoglycosidases suggest that the diffuse nature of these bands results from carbohydrate heterogeneity and that the abnormal sialoglycoproteins contain N-glycosidically linked oligosaccharides with repeating lactosamine units. Such polylactosamine chains are not present on normal beta or gamma.


1977 ◽  
Vol 164 (2) ◽  
pp. 465-468 ◽  
Author(s):  
D A W Grant ◽  
S Hjertén

Solubilization of the human erythrocyte membrane by seven detergents is described. Components released into the supernatant or retained in the residue were identified by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. Two non-ionic detergents exhibiting little u.v. absorption were more efficient than u.v.-absorbing Triton X-100. Evidence is presented of an interchange between protein PAS 1 and protein PAS 2.


1971 ◽  
Vol 125 (4) ◽  
pp. 1109-1117 ◽  
Author(s):  
M. J. A. Tanner ◽  
W. R. Gray

A protein, initially identified as a band on polyacrylamide-gel electrophoresis of erythrocyte ‘ghosts’, was isolated by selective extraction of ‘ghosts’ with EDTA solutions. The molecular weight of the polypeptide chain was estimated as 33000 and it represents approx. 5% of the membrane protein. The N-terminal sequence of the protein was established. Comparison with known protein sequences suggested that the protein might be the erythrocyte d-glyceraldehyde 3-phosphate dehydrogenase. This identification was confirmed by direct enzyme assay. It is suggested that this enzyme, which is strongly retained by erythrocyte ‘ghosts’ on haemolysis of erythrocytes, is unlikely to be an integral part of the structure of the erythrocyte membrane.


Blood ◽  
1984 ◽  
Vol 64 (3) ◽  
pp. 599-606
Author(s):  
MJ Telen ◽  
TJ Palker ◽  
BF Haynes

We have previously shown that a murine monoclonal antibody (A3D8) identifies a human erythrocyte protein antigen whose expression is regulated by the Lutheran inhibitor [In(Lu)] gene. In the present study, we demonstrated by immunoprecipitation and Western blot techniques that the antigen defined by A3D8 was on an 80-kD erythrocyte membrane protein. A second 170-kD protein was coprecipitated with the 80-kD protein but failed to show antigen activity by Western blot analysis. The 170-kD protein, when analyzed by sodium dodecyl sulfate- polyacrylamide gel electrophoresis in two dimensions, was composed of 50- and 30-kD disulfide-linked subunits. In(Lu) Lu[a-b-) erythrocytes differed from Lu(a+b+) or Lu(a-b+) erythrocytes in that In(Lu) deoxycholate erythrocyte membrane extracts contained trace amounts of immunoprecipitable 80-kD protein compared with detergent-solubilized erythrocyte membrane extracts prepared from Lu(a+b+) or Lu(a-b+) subjects.


1974 ◽  
Vol 137 (3) ◽  
pp. 531-534 ◽  
Author(s):  
D. H. Boxer ◽  
R. E. Jenkins ◽  
M. J. A. Tanner

The enzyme lactoperoxidase was used to catalyse the radioiodination of membrane proteins in intact human erythrocytes and in erythrocyte ‘ghosts’. Two major proteins of the erythrocyte membrane were isolated after iodination of these two preparations, and the peptide ‘maps’ of each protein so labelled were compared. Peptides from both proteins are labelled in the intact cell. In addition, further mobile peptides derived from one of the proteins are labelled only in the ‘ghost’ preparation. Various sealed ‘ghost’ preparations were also iodinated, lactoperoxidase being present only at either the cytoplasmic or extra-cellular surface of the membrane. The peptide ‘maps’ of protein E (the major membrane protein) labelled in each case were compared. Two discrete sets of labelled peptides were consistently found. One group is obtained when lactoperoxidase is present at the extra-cellular surface and the other group is found when the enzyme is accessible only to the cytoplasmic surface of the membrane. The results support the assumption that the organization of protein E in the membrane of the intact erythrocyte is unaltered on making erythrocyte ‘ghosts’. They also confirm previous suggestions that both the sialoglycoprotein and protein E extend through the human erythrocyte membrane.


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