Solubilized Glycoprotein from Human Erythrocyte Membranes Possessing Blood Group A, B and H Activity1

Summary. Human erythrocyte ghosts where prepared by osmotic lysis and washed thoroughly with deionized distilled water. The resultant stroma were extracted twice with n‐butanol producing 81.8 % ± 2.7 solubilization of the membrane protein. The initial extract contained 5 % of the lipid present in intact ghosts. The second extract contained no detectable lipids. The solubilized glycoprotein possessed A, B and H blood group activity comparable to that of the intact ghosts at the same protein concentration. Fractionation studies suggested that the maximum serological activity was associated with a high molecular weight structure. In contrast to most previous work demonstrating A, B and H blood group activities to be exhibited by erythrocyte glycolipids this study reports these blood group specificities to be present in human erythrocyte membrane glycoprotein.