Human Monocytes - CD14, CD16 - Ziegler-Heitbrock

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Lectin domain peptides from selectins interact with both cell surface ligands and Ca2+ ions

Abstract

Selectins are receptors that mediate leukocyte adhesion to platelets or endothelial cells through Ca(2+)-dependent interactions with cell surface oligosaccharides. We found that peptides corresponding to residues 23-30, 54-63, and 70-79 of the N-terminal lectin domain of P-selectin inhibited leukocyte adhesion to P-selectin. Peptides corresponding to the homologous 23-30 and 54-63 regions of E-selectin and L-selectin also prevented cell binding to P-selectin. Immobilized albumin conjugates of the three P-selectin peptides supported adhesion of myeloid cells and certain other cells expressing fucosylated oligosaccharides. Ca2+ was required for optimal cell adhesion to the conjugates containing the 23-30 and 54-63 sequences. Furthermore, Ca2+ interacted with the 23-30 and 54-63 peptides of all three selectins, as detected by changes in intrinsic fluorescence emission intensity. These data suggest that residues contained within the 23-30 and 54-63 regions of the selectins represent contact sites for carbohydrate structures on target cells. Furthermore, binding of Ca2+ to these sequences may directly enhance their ability to interact with cell surface ligands.

Authors: Geng, J.-G., Heavner, G.A., McEvert, R.P.
Journal: J. Biol. Chem., 267: 19846-19853
Year: 1992
PubMed: Find in PubMed