Enzymatic Synthesis of Blood‐Group Lewis‐Specific Glycolipids

Abstract

A blood‐group Lewis precursor glycolipid was isolated from the plasma of a Lewis‐negative individual [Le(a–b–)] and treated with fucosyltransferases from human gastric mucosa and GDP‐fucose. Subsequently the glycolipid was adsorbed onto Le(a–b–) erythrocytes and the presence of blood‐group Lewis antigens was assessed by passive hemagglutination with anti‐Lewis sera. It was shown that the precursor glycolipid was enzymatically transformed to blood‐group Lewis a (Le a ) and Lewis b (Le b ) specific glycolipids. Le b ‐glycolipid was also synthesized by fucosylation of an isolated Le a ‐glycolipid. Moreover Le(a–b–) erythrocytes were shown to develop Le a and Le b activities when subjected to enzymatic fucosylation, thus showing that Lewis‐negative cells carry blood‐group Lewis precursor glycolipid on the surface of their membrane. Le(a + b‐) erythrocytes, upon enzymatic fucosylation, acquired Le b activity.