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.