Composition and subunit structure of the cell receptor for immunoglobulin E.
The principal surface glycoprotein which specifically binds immunoglobulin E was isolated from rat basophilic leukemia cells in sufficient amounts for compositional and end group analyses. The protein has about 30% carbohydrate and a relatively low content of hydrophobic amino acid residues. No NH2-terminal residue was found by standard methods. The data suggest a Mr approximately equal to 50,000. The latter value is calculated on the basis of 1 molecule of receptor binding 1 molecule of immunoglobulin E. New data confirmed this valence. We propose a provisional model in which the principal component which binds immunoglobulin E is a monomer which, in cells and in nondenaturing solvents, is associated in a 1:1 ratio with the polypeptide of Mr approximately equal to 30,000 recently defined by studies employing cross-linking reagents.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002241:Carbohydrates / Q000032:analysis; D055598:Chemical Phenomena; D002621:Chemistry; D007073:Immunoglobulin E / Q000378:metabolism*; D007942:Leukemia, Experimental / Q000276:immunology; D046911:Macromolecular Substances; D008565:Membrane Proteins / Q000032:analysis; D008970:Molecular Weight; D051381:Rats; D011971:Receptors, Immunologic / Q000302:isolation & purification*
D000596:Amino Acids; D002241:Carbohydrates; D046911:Macromolecular Substances; D008565:Membrane Proteins; D011971:Receptors, Immunologic; D007073:Immunoglobulin E