A series of human erythrocyte glycosphingolipids reacting to the monoclonal antibody directed to a developmentally regulated antigen SSEA-1.

A series of glycolipid antigens reacting with the monoclonal antibody directed to the stage-specific embryonic antigen 1 was isolated and characterized from group O human erythrocyte membranes. A ceramide heptasaccharide (Structure 1), ceramide nonasaccharide (Structure 2), and ceramide decasaccharide (Structure 3) have been characterized (formula, see text) The main feature of this glycolipid series is its long core sugar chain with a nonbranched repeating N-acetyllactosamine (norpolylactosamine). This characteristic is in contrast to that of co-existing H-active glycolipid series in which the longer core structures are branched type repeating N-acetyllactosamine (isopolylactosamine). The reactivity of these glycolipids to monoclonal anti-stage-specific embryonic antigen 1 antibody varied proportionately to the length of their core sugar chains. A possible significance of these glycolipids as developmentally regulated antigens and as cancer-associated antigens was discussed.