Lactose as affinity eluent and a synthetic sulfated copolymer as inhibitor, in conjunction with synthetic and natural acceptors, differentiate human milk lewis-type and plasma-type α-L-fucosyltransferases

Human milk Lewis-type (αl,3/4) fucosyltransf erase (FT) was separated from the plasma-type by chromatography on bovine IgG glycopep-Sepharose using lactose as the selective eluent and further purified on a column of Sephacryl S-100 HR. The α1, 3-FT activity towards 2′-fucosyllactose was found to be associated with αl, 4-FT activity. The inherency of N-acetyl-glucosaminide α1, 3-L-FT activity in the Lewis-type FT was shown by a) the emergence of both α1, 3- and α1, 4-FT activities from the Sephacryl S-100 HR column in the same position; b) the inhibition of the α1, 3-FT activity in the Lewis-type FT by α1, 4-FT specific inhibitor namely a copolymer from 3-sulfoGalβl, 3GlcNAcβ-0-Allyl and acrylamide; c) the inhibition of α1, 4 activity in the Lewis-type FT by α1, 3-FT specific acceptor. Fetuin triantennary sialoglycopeptide, the corresponding asialo glycopeptide, and bovine IgG diantennary glycopeptide served as acceptors for both FTs, the Lewis-type FT being far more active than the plasma type FT towards the triantennary sialoglycopeptide.