title: Improved enzymatic synthesis of a highly potent oligosaccharide antagonist of L-selectin.
abstract: The polylactosamine sLex beta1-3'(sLex beta1-6')LacNAc beta1-3'(sLex beta1-6')LacNAc beta1-3'(sLex beta1-6')LacNAc (7) (where sLex is Neu5Ac alpha2-3Gal beta1-4(Fuc alpha1-3)GlcNAc and LacNAc is Gal beta1-4GlcNAc) is a nanomolar L-selectin antagonist and therefore a potential anti-inflammatory agent (Renkonen et al. (1997) Glycobiology, 7, 453). Here we describe an improved synthesis of 7. The octasaccharide LacNAc beta1-3'LacNAc beta1-3'LacNAc beta1-3'LacNAc (4) was converted into the triply branched undecasaccharide LacNAc beta1-3'(GlcNAc beta1-6')LacNAc beta1-3'(GlcNAc beta1-6')LacNAc beta1-3'(GlcNAc beta1-6')LacNAc (5) by incubation with UDP-GlcNAc and the midchain beta1,6-GlcNAc transferase activity of rat serum. Glycan 5 was enzymatically beta1,4-galactosylated to LacNAc beta1-3'(LacNAc beta1-6')LacNAc beta1-3'(LacNAc beta1-6')LacNAc beta1-3'(LacNAc beta1-6')LacNAc (6). Combined with the enzymatic conversion of 6 to 7 (Renkonen et al., loc. cit.) and the available chemical synthesis of 4, our data improve the availability of 7 for full assessment of its anti-inflammatory properties.
authors.affiliation: Institute of Biotechnology and Department of Biosciences, University of Helsinki, Finland.
authors.forename: H
authors.initials: H
authors.lastname: Salminen
authors.forename: K
authors.initials: K
authors.lastname: Ahokas
authors.forename: R
authors.initials: R
authors.lastname: Niemelä
authors.forename: L
authors.initials: L
authors.lastname: Penttilä
authors.forename: H
authors.initials: H
authors.lastname: Maaheimo
authors.forename: J
authors.initials: J
authors.lastname: Helin
authors.forename: C E
authors.initials: CE
authors.lastname: Costello
authors.forename: O
authors.initials: O
authors.lastname: Renkonen
mesh_terms: D000818:Animals; D002240:Carbohydrate Sequence; D019041:L-Selectin / Q000187:drug effects*; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000138:chemical synthesis* / Q000494:pharmacology*; D051381:Rats
chemical_list: D009844:Oligosaccharides; D019041:L-Selectin