A plant fucosyltransferase with human Lewis blood-group specificity.
A fucosyltransferase from mung bean seedling was found to transfer L-fucose from GDP-fucose to the Type 1 disaccharide beta-D-Galp-(1----3)-beta-D-GlcpNAc-OR [R = (CH2)8COOMe]. The product, which was detected by an anti-Lea antibody in a novel ELISA assay, was isolated and shown to be the human Lea blood-group determinant beta-D-Galp-(1----3)-[alpha-L-Fucp-(1----4)]-beta-D-GlcpNAc-OR by 1H-n.m.r. spectroscopy. This enzyme activity is distinct from that of the human Lewis-fucosyl-transferase since alpha-L-Fucp-(1----2)-beta-D-Galp-(1----4)-beta-D-Glcp-OR is a very poor substrate, while the Type 2 disaccharide beta-D-Galp-(1----4)-beta-D-GlcpNAc-OR is not an acceptor. In common with the Lewis fucosyltransferase, the H-Type 1 trisaccharide alpha-L-Fucp-(1----2)-beta-D-Galp-(1----3)-beta-D-GlcpNAc-OR was an excellent substrate for the enzyme. This new enzyme activity was further characterized with respect to pH, nucleotide, Mn2+ dependence, and acceptor specificity against a panel of synthetic oligosaccharides.
Crawley
S C
SC
Department of Chemistry, University of Alberta, Edmonton, Canada.
Hindsgaul
O
O
Ratcliffe
R M
RM
Lamontagne
L R
LR
Palcic
M M
MM
D002240:Carbohydrate Sequence; D004797:Enzyme-Linked Immunosorbent Assay; D007887:Fabaceae / Q000201:enzymology*; D005647:Fucosyltransferases / Q000378:metabolism*; D006602:Hexosyltransferases / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D007983:Lewis Blood Group Antigens; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D010946:Plants, Medicinal; D013379:Substrate Specificity
D007983:Lewis Blood Group Antigens; D005647:Fucosyltransferases; D006602:Hexosyltransferases