Isolation and characterization of band 3, the predominant polypeptide of the human erythrocyte membrane.

摘要: Band 3 is the predominant approximately 90,000-dalton polypeptide component of human erythrocyte membrane. It was solubilized selectively, along with other major glycoproteins, by extracting membrane ghosts Triton X-100 under nondenaturing conditions. Two polypeptides remained associated these conditions; however one (Band 6) could be dissociated at an ionic strength 0.15 and 4.2) treatment p-chloromercuribenzoate. then purified (greater than or equal to 97%) aminoethyl cellulose ion exchange chromatography. The isolated protein free phospholipid moderately enriched in apolar amino acid residues; it contained galactose glucosamine but very little sialic galactosamine. When labeled oxidase plus KB3H4 purified, electrophoretic mobility its radioactivity lagged slightly behing that Coomassie blue staining profile. Variation glycosylation therefore cause diffuse trailing zone characteristically observed for on polyacrylamide gel electrophoresis sodium dodecyl sulfate. ultraviolet circular dichroism stable nonionic detergent suggested alpha helix content 43%, a value close estimated this