title: Enzymatic synthesis of a 6'-sulphated sialyl-Lewisx which is an inhibitor of L-selectin binding to peripheral addressin.
abstract: A sulphated form of sialyl-Lewisx, NeuAc alpha 2-3Gal beta 1-4(Fuc alpha 1-3)GlcNAc6OSO3 beta 1-3Gal, was synthesized enzymatically from a precursor disaccharide, GlcNAc6OSO3 beta 1-3Gal, using sequential steps involving beta 1,4-galactosyltransferase, alpha 2,3-trans-sialidase and recombinant alpha 1,3-fucosyltransferase, respectively. Successful enzymatic fucosylation at the 3 position of the GlcNAc6OSO3 residue demonstrated that fucosyltransferase are capable of generating, in situ, sulphated sialyl Lewisx structures containing sulphate at the 6 position of GlcNAc. The sulphated sialyl-Lewisx pentasaccharide produced by this procedure inhibited binding of a soluble form of L-selectin to 35SO4-labelled peripheral addressin with an IC50 of 0.8 mM, whereas sialyl-Lewisx tetrasaccharide was a weaker inhibitor, displaying an IC50 of 3.2 mM. Hemmerich and Rosen (Biochemistry, 33, 4820-4829, 1994) recently reported the presence of Gal beta 1-4GlcNAcO6SO3 structures on murine peripheral addressin Sgp50, in addition to sialyl Lewisx structures sulphated at the 6-O-galactose position. Based on our data, we suggest that sialyl Lewisx sulphated at the 6-O-GlcNAc position may also exist on receptors and function as a ligand for L-selectin.
authors.affiliation: Department of Immunology, G.D. Searle Co., Monsanto Co., St Louis, MO 63167, USA.
authors.forename: P R
authors.initials: PR
authors.lastname: Scudder
authors.forename: K
authors.initials: K
authors.lastname: Shailubhai
authors.forename: K L
authors.initials: KL
authors.lastname: Duffin
authors.forename: P R
authors.initials: PR
authors.lastname: Streeter
authors.forename: G S
authors.initials: GS
authors.lastname: Jacob
mesh_terms: D000818:Animals; D000954:Antigens, Surface / Q000737:chemistry / Q000378:metabolism*; D002240:Carbohydrate Sequence; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D066298:In Vitro Techniques; D019041:L-Selectin; D016256:Lewis X Antigen / Q000031:analogs & derivatives; D008024:Ligands; D013058:Mass Spectrometry; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000096:biosynthesis* / Q000737:chemistry / Q000378:metabolism; D000080506:Sialyl Lewis X Antigen / Q000031:analogs & derivatives
chemical_list: C086949:6'-sulfated sialyl Lewis x; D000954:Antigens, Surface; D015815:Cell Adhesion Molecules; C069886:L-selectin counter-receptors; D016256:Lewis X Antigen; D008024:Ligands; D008565:Membrane Proteins; D009844:Oligosaccharides; D000080506:Sialyl Lewis X Antigen; D019041:L-Selectin