A single amino acid residue can determine the ligand specificity of E-selectin.
E-selectin (ELAM-1) is a member of the selectin family of cellular adhesion molecules. This family of proteins possesses an amino-terminal Ca(2+)-dependent lectin or carbohydrate recognition domain that is essential for ligand binding. A known E-selectin ligand is the carbohydrate antigen, sialyl Lewis(x) (sLe(x) (Neu5Ac alpha 2-3Gal beta 1-4(Fuc alpha 1-3)GlcNAc). We have developed a model of E-selectin binding to the sLe(x) tetrasaccharide, (Neu5Ac alpha 2-3Gal beta 1-4(Fuc alpha 1-3)GlcNAc), using the NMR-determined, E-selectin-bound solution conformation of sLe(x) (Cooke, R.M., Hale, R.S., Lister, S. G., Shah, G., and Weir, M. P. (1994) Biochemistry 33, 10591-10596) together with the x-ray crystallographic structures of E-selectin (Graves, B. J., Crowther, R. L., Chandran, C., Rumberger, J. B., Li, s., Huang, K.-S., Presky, D. H., Familletti, P. C., Wolitzky, B. A., and Burns, D. K. (1994) Nature 367, 532-538) (ligand unbound) and a related C-type animal lectin, the mannose-binding protein (Weis, W. I., Drickamer, K., and Hendrickson, A. (1992) Nature 360, 127-134) (ligand bound). Analysis of this model indicated that the alteration of one E-selectin amino acid, alanine 77, to a lysine residue might shift binding specificity from sLe(x) to mannose. The results presented here show that an E-selectin mutant protein possessing this change displays preferential binding to mannose containing oligosaccharides and that further mutagenesis of this mannose-binding selectin confers galactose recognition in a predictable manner. These mutagenesis data support the presented model of the detailed interactions between E-selectin and the sLe(x) oligosaccharide.
Kogan
T P
TP
Department of Molecular Biology, Texas Biotechnology Corporation, Houston, USA.
Revelle
B M
BM
Tapp
S
S
Scott
D
D
Beck
P J
PJ
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D002478:Cells, Cultured; D019040:E-Selectin; D016256:Lewis X Antigen / Q000378:metabolism; D008024:Ligands; D008358:Mannose / Q000378:metabolism; D008969:Molecular Sequence Data; D016296:Mutagenesis; D012680:Sensitivity and Specificity; D013329:Structure-Activity Relationship
D015815:Cell Adhesion Molecules; D019040:E-Selectin; D016256:Lewis X Antigen; D008024:Ligands; D008358:Mannose