Systematic synthesis of sulfated sialyl-α-(2→3)-neolactotetraose derivatives and their acceptor specificity for an α-(1→3)-fucosyltransferase (Fuc-TVII) involved in the biosynthesis of L-selectin ligand
作者:Kyoko Fukunaga、Katsumi Shinoda、Hideharu Ishida、Makoto Kiso
DOI:10.1016/s0008-6215(00)00088-4
日期:2000.9
Sulfated sialyl-alpha-(2 --> 3)-neolactotetraose (IV(3)NeuAcnLcOse(4)) derivatives at C-6 of GlcNAc (6-O-sulfo), terminal Gal (6'-O-sulfo), and both GlcNAc and Gal (6,6'-di-O-sulfo) residues have systematically been synthesized. (Methyl 5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-D-glycero-alpha-D-galacto-2-nonulopyranosylonate)-(2 --> 3)-2,4-di-O-benzoyl-6-O-levulinoyl-D-galactopyranosyl trichloroacetimidate was coupled with 2-(trimethylsilyl)ethyl (2-acetamido-2-deoxy-3-O-benzyl-6-O-p-methoxyphenyl-beta-D-glucopyranosyl)-(1 --> 3)-(2,4,6-tri-O-benzyl-beta-D-galactopyranosyl)-(1 --> 4)-2,3,6-tri-O-benzyl-beta-D-glucopyranoside to give the suitably protected pentasaccharide which, upon selective removal of the p-methoxyphenyl and/or levulinoyl groups at C-6 of the GlcNAc and the terminal Gal residues, successive O-sulfation(s) and deprotection, afforded the desired three sulfated IV(3)NeuAcnLcOse(4) derivatives. Acceptor specificity of the synthetic IV(3)NeuAcnLcOse(4) probes for a human alpha-(1 --> 3)-fucosyltransferase (Fuc-TVII) was examined to study the biosynthetic pathway of L-selectin ligand. Only the 6-sulfated derivative at C-6 of GlcNAc was recognized by Fuc-TVII to give 6-O-sulfo sialyl Le(X). (C) 2000 Elsevier Science Ltd. All rights reserved.