title: Tandem exploitation of Helix pomatia glycosyltransferases: facile syntheses of H-antigen-bearing oligosaccharides.
abstract: Snails from the family Helicidae produce in their albumen glands a highly branched galactan, which consists almost exclusively of D- and L-galactose. The D-Gal residues are glycosydically beta(1-->6)- or beta(1-->3)-linked, whereas the L-Gal moieties are attached alpha(1-->2). Up until the present time, two beta(1-->6)-D-galactosyl transferases and one alpha(1-->2)-L-galactosyl transferase have been identified in a membrane preparation of these glands. These were used to synthesise various oligosaccharides by successive addition of the NDP-activated (NDP=nucleoside-5'-diphosphate) D-Gal or L-Fuc moieties, up to a heptasaccharide by starting from the disaccharide D-Gal-beta(1-->3)-D-Gal-beta(1-->OMe. Even larger oligosaccharides up to a tridecasaccharide were obtained by starting with the hexasaccharide D-Gal-[beta(1-->3)-D-Gal]4-beta(1-->4)-D-Glc as an acceptor substrate. This tandem exploitation process has high potential for the easy introduction of D-Gal and L-Fuc residues into a great variety of oligosaccharides, which can be used in ligand/acceptor studies.
authors.affiliation: University of Hamburg, Faculty of Science, Department of Biology, 20146 Hamburg, Germany.
authors.forename: Hagen
authors.initials: H
authors.lastname: Bretting
authors.forename: Friedrich
authors.initials: F
authors.lastname: Buck
authors.forename: Günter
authors.initials: G
authors.lastname: Jacobs
authors.forename: Sebastian
authors.initials: S
authors.lastname: Meinke
authors.forename: Angela M
authors.initials: AM
authors.lastname: Scheppokat
authors.forename: Joachim
authors.initials: J
authors.lastname: Thiem
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000737:chemistry; D002240:Carbohydrate Sequence; D002384:Catalysis; D005858:Germany; D006031:Glycosylation; D016695:Glycosyltransferases / Q000378:metabolism*; D015394:Molecular Structure; D009844:Oligosaccharides / Q000138:chemical synthesis* / Q000737:chemistry; D012908:Snails / Q000201:enzymology*
chemical_list: D000942:Antigens, Bacterial; C022863:H antigen; D009844:Oligosaccharides; D016695:Glycosyltransferases