Carbohydrate analysis of human von Willebrand factor with horseradish peroxidase-conjugated lectins

Human von Willebrand factor (vWF) immobilized on a polyvinylidene difluoride membrane was subjected to binding assay with a series of horseradish peroxidase-conjugated lectins. The protein was reactive with concanavalin A, Ricinus communis agglutinin 120, wheat germ agglutinin and Ulex europaeus agglutinin I (UEA-I) but not with peanut agglutinin before sialidase treatment. These reactivities were consistent with the major oligosaccharide structure reported except for UEA-I. The reactivity with UEA-I was greatly decreased after digestion of the protein with either α-L-fucosidase or peptide-N-glycosidase F, but no significant decrease was observed after mild alkaline treatment or delipidation. vWF and UEA-I have been independently used as a good marker for human endothelial cells. Our results indicate that vWF itself contains UEA-I reactive sugar chains in its Asn-linked oligosaccharides.