title: Separation and some properties of the major proteins of the human erythrocyte membrane.
abstract: A fractionation procedure is described which allows the isolation of three major human erythrocyte membrane proteins. Their isolation involves three sequential extraction procedures followed by gel filtration in 1% sodium dodecyl sulphate and preparative gel electrophoresis. All three proteins can be isolated from a single preparation. One of the proteins is the erythrocyte sialoglycoprotein, for which no C- or N-terminal residues were found. The other two proteins, which have not previously been isolated, have subunit molecular weights of 74000 and 93000 and contain 9 and 7% carbohydrate respectively. These glycoproteins have blocked N-terminal residues and show similarities in their chemical properties. Preparations derived from blood-group O erythrocytes contain no N-acetylgalactosamine, but similar preparations from blood-group A erythrocytes do contain this sugar. These three proteins cannot easily be solubilized by gentle aqueous procedures and represent about half of the erythrocyte ;ghost' protein. They carry a large proportion of the cell-surface carbohydrate.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D001789:Blood Group Antigens; D001798:Blood Proteins / Q000032:analysis / Q000302:isolation & purification*; D002241:Carbohydrates / Q000032:analysis; D002458:Cell Fractionation; D002462:Cell Membrane / Q000032:analysis; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D004912:Erythrocytes / Q000032:analysis*; D005613:Freeze Etching; D005688:Galactosamine / Q000302:isolation & purification; D006023:Glycoproteins / Q000302:isolation & purification; D006801:Humans; D008854:Microscopy, Electron; D008970:Molecular Weight; D011725:Pyridines; D012967:Sodium Dodecyl Sulfate
chemical_list: D000596:Amino Acids; D001789:Blood Group Antigens; D001798:Blood Proteins; D002241:Carbohydrates; D006023:Glycoproteins; D011725:Pyridines; D012967:Sodium Dodecyl Sulfate; D005688:Galactosamine