title: Synthesis of beta-D-GlcpNAc-(1-->2)-5a-carba-alpha-D-Man p-(1-->6)-beta-D- Glcp-O(CH2)7CH3: a reactive acceptor analog for N-acetylglucosaminyltransferase-V.
abstract: The branching enzyme N-acetylglucosaminyltransferase-V (GlcNAcT-V) recognizes the trisaccharide beta-D-GlcpNAc-(1-->2)-alpha-D-Man p-(1-->6)-beta-D-Glcp-O(CH2)7CH3 (1) as its minimum substrate. We report here the chemical synthesis of beta-D-GlcpNAc-(1-->2)-5a- carba-alpha-D-Manp-(1-->6)-beta-D-Glcp-O(CH2)7CH3 (2), a carbocyclic analog of 1 where the ring oxygen of the alpha-D-Manp residue is replaced by a methylene group. Trisaccharide 2 was found to be fully active as an acceptor for GlcNAcT-V, both with the enzyme isolated from hamster kidney and the one cloned from rat kidney. The kinetic parameters Km and Vmax for 1 and 2 were functionally equivalent. A preparative glycosylation reaction was performed using 2 as the acceptor with the cloned rat kidney enzyme. A tetrasaccharide formed by the addition of a Glc pNAc residue was the sole product as detected by 1H NMR spectroscopy and FAB mass spectrometry and was assigned the structure beta-D-GlcpNAc-(1-->2)-[beta-D-GlcpNAc-(1-->6)]-5a- carba-alpha-D-Manp-(1-->6)-beta-D-Glc p-O(CH2)7CH3 (13).
authors.affiliation: Department of Applied Chemistry, Faculty of Science and Technology, Keio University, Yokohama, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Ogawa
authors.forename: T
authors.initials: T
authors.lastname: Furuya
authors.forename: H
authors.initials: H
authors.lastname: Tsunoda
authors.forename: O
authors.initials: O
authors.lastname: Hindsgaul
authors.forename: K
authors.initials: K
authors.lastname: Stangier
authors.forename: M M
authors.initials: MM
authors.lastname: Palcic
mesh_terms: D000818:Animals; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D006224:Cricetinae; D006031:Glycosylation; D007668:Kidney / Q000201:enzymology; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D015394:Molecular Structure; D017351:N-Acetylglucosaminyltransferases / Q000378:metabolism*; D051381:Rats; D014312:Trisaccharides / Q000138:chemical synthesis* / Q000378:metabolism
chemical_list: D014312:Trisaccharides; C095419:octyl 6-O-(2-O-(2-acetamido-2-deoxyglucopyranosyl)-5a-carbamannopyranosyl)glucopyranoside; D017351:N-Acetylglucosaminyltransferases; C052254:alpha-1,6-mannosylglycoprotein beta 1,6-N-acetylglucosaminyltransferase