Human salivary fucosyltransferases: Evidence for two distinct α-3-L-fucosyltransferase activities one of which is associated with the lewis blood group [formula omitted] gene

Abstract

The occurrence of GDP-L-fucose:N-acetyl-β-D-glucosaminyl α-3-L-fucosyltransferase activity in human saliva was independent of Lewis blood group and ABH secretor status except insofar as the mean level of activity was higher in saliva from individuals with an Le gene than in those whose red cells and saliva grouped as Le(a-b-). In contrast GDP-L-fucose:D-glucose α-3-L-fucosyltransferase activity was detectable in saliva from all Le(a+b-) and Le(a-b+) individuals but was absent from the salivas of Le(a-b-) donors. Isoelectric focusing experiments supported the inference that there are two distinct α-3-L-fucosyltransferase activities in saliva. Both enzymes appear to catalyse the transfer of L-fucose to the C-3 position of N-acetyl-β-D-glucosamine but only the transferase dependent upon the expression of the Le gene has the capacity to transfer L-fucose to the C-3 position of D-glucose.