Comparative study of A, B, and H substances in stromas with and without lipid removal. Studies of the erythrocyte membrane

Human erythrocyte membranes were prepared by hypotonic hemolysis and extracted with water pH 7, EDTA and mercapto-ethanol solutions pH 8. The complex residue which contains lipids, proteins and the A, B, H antigens was dissolved in SDS and analysed by preparative acrylamide gel electrophoresis in the presence of SDS. Each fraction was assayed for A, B or H blood-group activity by hemagglutination inhibition tests. Two experiments were done for each blood-group A, B, O. One with entire ghosts, another after extraction of the ghosts residue with a mixture of chloroform-methanol. The comparison of results showed that the distribution of proteins and blood-group antigen activity among the different fractions is not modified and that, in the two experiments, the elution of H substance is delayed by comparison with elution of A and B substances. The blood-group A, B and H antigens are known to be glycosphingolipids and are not entirely eliminated by treatment of the ghosts with cloroform and methanol. It has recently been reported [7] that these antigens are complex glycosphingolipids with hydrophilic character and remain in the aqueous phase after extraction of the erythrocyte membrane with organic solvents.