Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
J Biol Chem. 1994 Sep 16;269(37):23318-27.

The P-selectin glycoprotein ligand from human neutrophils displays sialylated, fucosylated, O-linked poly-N-acetyllactosamine.

Author information

  • 1Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City.

Abstract

We previously demonstrated that P-selectin binds with high affinity to a trace, homodimeric glycoprotein ligand on human myeloid cells. The ligand carries the sialyl Lewis x (sLe(x)) epitope, a limited number of N-linked glycans, and clustered, sialylated O-linked glycans. In this study we demonstrate that the polypeptide component of this ligand is identical to that of P-selectin glycoprotein ligand-1 (PSGL-1), a molecule recently identified by expression cloning from a human myeloid cell cDNA library. We have examined the effects of glycosidases on purified, radioiodinated PSGL-1 from human neutrophils to further characterize the structure and function of the attached oligosaccharides. We found that PSGL-1 had poly-N-acetyllactosamine, only some of which could be removed with endo-beta-galactosidase. The majority of the Le(x) and sLe(x) structures were on endo-beta-galactosidase-sensitive chains. Peptide:N-glycosidase F (PNGaseF) treatment removed at least two of the three possible N-linked oligosaccharides from PSGL-1. Expression of Le(x) and sLe(x) was not detectably altered by PNGaseF digestion, indicating that these structures were primarily on O-linked poly-N-acetyllactosamine. Endo-beta-galactosidase-treated PSGL-1 retained the ability to bind to P-selectin, suggesting that some of the oligosaccharides recognized by P-selectin were either on enzyme-resistant poly-N-acetyllactosamine or on chains which lack poly-N-acetyllactosamine. PNGaseF treatment did not affect the ability of PSGL-1 to bind to P-selectin, demonstrating that the oligosaccharides required for P-selectin recognition are O-linked. PSGL-1 also bound to E-selectin, but with at least 50-fold lower affinity than to P-selectin. These data suggest that PSGL-1 from human neutrophils displays complex, sialylated, and fucosylated O-linked poly-N-acetyllactosamine that promote high affinity binding to P-selectin, but not to E-selectin.

PMID:
7521878
[PubMed - indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Icon for HighWire
    Loading ...
    Write to the Help Desk