Isolation and characterization of glycolipids from erythrocytes of human blood A (plus) and B (plus).

The presence in horse erythrocytes of a glycolipid composed of sphingosine, fatty acids, hexoses, and neuraminic acid was reported by Yamakawa and Suzuki (1). A similar product was isolated by Klenk and Lauenstein (2) from human erythrocytes; it contained galactosamine, but no neuraminic acid. Further studies by Klenk and Lauenstein (3) and by Yamakawa and Suzuki (4) and Matsumoto (5) showed that the composition of the glycolipids varies with the source of the erythrocytes. Blood group activity has generally been associated with substances of glycoprotein nature, isolated from glandular tissues and secretions (6). The chemical nature of the substances responsible for blood group activity in erythrocytes has not been clearly established, and contradictory statements have been made in the past concerning their chemical nature (7-9). Recently, Yamakawa et al. reported blood group activity in a glycolipid fraction (lo), but it could not be related to a definite chemical structure (11). The purpose of the present work was to purify glycolipid fractions possessing blood group activity starting from two different types of human blood, A ( +) and B ( +), and further to study the chemical differences between the purified substances. In agreement with the evidence presented by Yamakawa and Iida (lo), it was shown that each glycolipid isolated was able to inhibit the hemagglutination of its parent erythrocyte by the corresponding antibody. After the present work had been completed, independent investigations by I&din (12), and by Koscielak and Zakrzewski (13), as well as a reinvestigation by Klenk of substances previously isolated (14), led to the same conclusions.