title: 1,3-1,4-α-L-fucosynthase that specifically introduces Lewis a/x antigens into type-1/2 chains.
abstract: α-L-fucosyl residues attached at the non-reducing ends of glycoconjugates constitute histo-blood group antigens Lewis (Le) and ABO and play fundamental roles in various biological processes. Therefore, establishing a method for synthesizing the antigens is important for functional glycomics studies. However, regiospecific synthesis of glycosyl linkages, especially α-L-fucosyl linkages, is quite difficult to control both by chemists and enzymologists. Here, we generated an α-L-fucosynthase that specifically introduces Le(a) and Le(x) antigens into the type-1 and type-2 chains, respectively; i.e. the enzyme specifically accepts the disaccharide structures (Galβ1-3/4GlcNAc) at the non-reducing ends and attaches a Fuc residue via an α-(1,4/3)-linkage to the GlcNAc. X-ray crystallographic studies revealed the structural basis of this strict regio- and acceptor specificity, which includes the induced fit movement of the catalytically important residues, and the difference between the active site structures of 1,3-1,4-α-L-fucosidase (EC 3.2.1.111) and α-L-fucosidase (EC 3.2.1.51) in glycoside hydrolase family 29. The glycosynthase developed in this study should serve as a potentially powerful tool to specifically introduce the Le(a/x) epitopes onto labile glycoconjugates including glycoproteins. Mining glycosidases with strict specificity may represent the most efficient route to the specific synthesis of glycosidic bonds.
authors.affiliation: Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, Nonoichi, Ishikawa 921-8836, Japan.
authors.forename: Haruko
authors.initials: H
authors.lastname: Sakurama
authors.forename: Shinya
authors.initials: S
authors.lastname: Fushinobu
authors.forename: Masafumi
authors.initials: M
authors.lastname: Hidaka
authors.forename: Erina
authors.initials: E
authors.lastname: Yoshida
authors.forename: Yuji
authors.initials: Y
authors.lastname: Honda
authors.forename: Hisashi
authors.initials: H
authors.lastname: Ashida
authors.forename: Motomitsu
authors.initials: M
authors.lastname: Kitaoka
authors.forename: Hidehiko
authors.initials: H
authors.lastname: Kumagai
authors.forename: Kenji
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Takane
authors.initials: T
authors.lastname: Katayama
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D001644:Bifidobacterium / Q000201:enzymology* / Q000235:genetics; D020134:Catalytic Domain; D000939:Epitopes / Q000737:chemistry; D005643:Fucose / Q000737:chemistry*; D005647:Fucosyltransferases / Q000737:chemistry* / Q000235:genetics; D006801:Humans; D007983:Lewis Blood Group Antigens; D009844:Oligosaccharides / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; D000939:Epitopes; D007983:Lewis Blood Group Antigens; C494219:Lewis a oligosaccharide; D009844:Oligosaccharides; D005643:Fucose; D005647:Fucosyltransferases