title: Facile enzymatic conversion of lactose into lacto-N-tetraose and lacto-N-neotetraose.
abstract: Lacto-N-tetraose (Galbeta1 -3GlcNAcbeta1-3Galbeta1-4Glc, LNT) and lacto-N-neotetraose (Galbeta1-4GlcNAcbeta1-3Galbeta1-4Glc, LNnT) were enzymatically synthesized by consecutive additions of GlcNAc and Gal residues to lactose. Lacto-N-triose II (GlcNAcbeta1-3Galbeta1-4Glc) was prepared first by the transfer of GlcNAc from UDP-GlcNAc to lactose by beta-1,3-N-acetylglucosaminyltransferase from bovine serum. The resulting lacto-N-triose II was converted into LNT and LNnT utilizing two kinds of beta-D-galactosidase-mediated transglycosylations. Thus, beta-D-galactosidase from Bacillus circulans ATCC31382 induced regioselective galactosyl transfer from o-nitrophenyl beta-D-galactoside to the OH-3" position of lacto-N-triose II, and commercially available beta-D-galactosidase from B. circulans to the OH-4" position of lacto-N-triose II. These convenient processes are suitable for large-scale preparations of LNT and LNnT. As another method, LNT was directly synthesized from lactose as an initial substance, utilizing lacto-N-biosidase (Aureobacterium sp. L-101)-mediated transglycosylation with Galbeta1-3GlcNAcbeta-pNP donor.
authors.affiliation: Department of Applied Biological Chemistry, Shizuoka University, Ohya, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Murata
authors.forename: T
authors.initials: T
authors.lastname: Inukai
authors.forename: M
authors.initials: M
authors.lastname: Suzuki
authors.forename: M
authors.initials: M
authors.lastname: Yamagishi
authors.forename: A T
authors.initials: AT
authors.lastname: Usui
mesh_terms: D000818:Animals; D001407:Bacillus / Q000737:chemistry; D002240:Carbohydrate Sequence; D002417:Cattle; D006031:Glycosylation; D007785:Lactose / Q000737:chemistry*; D008969:Molecular Sequence Data; D017351:N-Acetylglucosaminyltransferases / Q000737:chemistry; D009844:Oligosaccharides / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism; D001616:beta-Galactosidase / Q000737:chemistry
chemical_list: D009844:Oligosaccharides; C013084:lacto-N-neotetraose; D017351:N-Acetylglucosaminyltransferases; D001616:beta-Galactosidase; D007785:Lactose