HIGH-AFFINITY BINDING OF THE LEUKOCYTE ADHESION MOLECULE L-SELECTIN TO 3'-SULFATED-LEA AND 3'-SULFATED-LEX OLIGOSACCHARIDES AND THE PREDOMINANCE OF SULFATE IN THIS INTERACTION DEMONSTRATED BY BINDING-STUDIES WITH A SERIES OF LIPID-LINKED OLIGOSACCHARIDES

The binding of the leucocyte adhesion molecule L-selectin has been investigated toward several structurally defined lipid-linked oligosaccharides immobilized on silica gel chromatograms or plastic wells. In both assay systems the 3′-sulphated Lea/Lex type tetrasaccharides {A figure is presented} were more strongly bound than 3′-sialyl analogues. A considerable binding was observed to the 3′-sulphated oligosaccharide backbone in the absence of fucose but not to a 3′-sialyl analogue or fuco-oligosaccharide analogues lacking sulphate or sialic acid. Affinity for other sulphated saccharides: 3′-sulphoglucuronyl neolactotetraosyl ceramide and glycolipids with sulphate 3′-linked to terminal or sub-terminal galactose or N-acetylgalactosamine was detected in the chromatogram assay only. These studies, together with earlier reports that L-selectin binding to endothelium is inhibited by sulphatide, highlight the relative importance of sulphate in the adhesive specificity of this protein. © 1992.