α‐l‐FucosyItransferases in Human Serum from Donors of Different ABO, Secretor and Lewis Blood‐Group Phenotypes

Abstract

The presence of α‐l‐fucosyltransferases in human serum of different ABO, secretor and Lewis blood‐group phenotypes was investigated with guanosine diphosphate fucose as the sugar donor and low‐molecular‐weight oligosaccharides, or a macromolecular glycoprotein, as acceptors. In contrast to the α‐2‐l‐fucosyltransferases in human milk, submaxillary glands and stomach mucosa that occur only in ABH secretors, an enzyme that transfers l‐fucose to the C‐2 position of non‐reducing β‐galactosyl residues was found in the serum of all normal ABO donors irrespective of their ABH secretor‐nonsecretor status. The only sera in which the α‐2‐l‐fucosyltransferase was not demonstrable were three examples of the blood group Bombay Oh phenotype and one example of the Bh phenotype. An a‐3‐l‐fucosyltransferase that conveyed L‐fucose to the C‐3 position in N‐acetyl‐d‐glucosamine or d‐glucose occurred in all the sera examined including those from donors of the Bombay Oh and Bh phenotypes. a‐4‐l‐Fucosyltransferase activity was virtually absent from the sera, irrespective of the Lewis blood group of the donors. Copyright © 1972, Wiley Blackwell. All rights reserved