INFLUENCE OF TRANSFERRIN GLYCANS ON RECEPTOR-BINDING AND IRON-DONATION

Human bi-bi-antennary transferrin (Tf) was partially deglycosylated by subsequently incubating with one or more of the following exoglycosid ases: neuraminidase, beta-galactosidase or N-Acetyl-beta-D-glucosamini dase. Aglyco-Tf obtained from serum of a patient suffering from the Ca rbohydrate Deficient Glycoprotein syndrome was isolated. Receptor bind ing and the Tf and iron uptake capacities of the fully glycosylated-, partially deglycosylated- and aglyco-Tf were compared using the human hepatoma cell line PLC/PRF/5. No difference in binding capacity betwee n the iso-Tf fractions could be demonstrated, however, the Tf and iron uptake capacity of aglyco-Tf was clearly reduced compared with the ot her 71 fractions.