Abstract
Two different glycophorins were isolated from rabbit erythrocyte membranes. Crude glycophorin fraction prepared by extraction with lithium diiodosalicylate and partition in aqueous phenol contained water-soluble glycolipid in addition to glycophorins. After removal of the glycolipid from glycophorins by ion-exchange chromatography, glycophorins were effectively fractionated by two different techniques : gel chromatography on Bio-Gel A 1.5m and ion-exchange chromatography in the presence of a nonionic detergent, Ammonyx LO. Two glycophorins were isolated in a ratio of about 1 : 2 (10 mg and 18 mg/3 g lyophilized erythrocyte membranes). The minor component, designated glycophorin RA, was a sialoglycoprotein (42% protein and 58% carbohydrate) and the major one, designated glycophorin RB, was of smaller size and lower carbohydrate content (57% protein and 43% carbohydrate). Glycophorins RA and RB were also different in chemical composition and amino-terminal sequence. Further evidence that the structures of the two glycophorins are unrelated to each other was obtained by Ouchterlony immunodiffusion with lectins ; glycophorin RB precipitated with concanavalin A and Ricinus communis agglutinin, whereas glycophorin RA did not.
