Soluble monomeric P-selectin containing only the lectin and epidermal growth factor domains binds to P-selectin glycoprotein ligand-1 on leukocytes.

Published

Journal Article

Under shear stress, leukocytes use P-selectin glycoprotein ligand-1 (PSGL-1) to tether to and roll on P-selectin expressed on activated platelets or endothelial cells. P-selectin has an NH2-terminal lectin domain, an epidermal growth factor (EGF)-like motif, nine consensus repeats (CRs), a transmembrane domain, and a cytoplasmic tail. To determine whether the CRs are required for P-selectin to bind PSGL-1, we expressed a soluble protein (Lec-EGF) that contained only the lectin and EGF domains, plus a short C-terminal epitope tag. Electron microscopy and hydrodynamic analysis confirmed that Lec-EGF was monomeric, as previously shown for soluble P-selectin (sPS) that contained the lectin and EGF domains plus all nine CRs. Fluid-phase Lec-EGF or sPS inhibited binding of oligomeric125I-labeled membrane-derived P-selectin (mPS) to PSGL-1 on neutrophils and binding of 125I-PSGL-1 to immobilized mPS. The IC50 for inhibiting binding of mPS to neutrophils was fivefold greater for Lec-EGF than for sPS, whereas the IC50 for inhibiting binding of mPS to purified PSGL-1 was indistinguishable for Lec-EGF and sPS. Under static or shear conditions, neutrophils used PSGL-1 to tether to or roll on Lec-EGF that was captured by an immobilized monoclonal antibody to the C-terminal epitope. These data show that P-selectin requires only the lectin and EGF domains to bind to PSGL-1.

Full Text

Duke Authors

Cited Authors

  • Mehta, P; Patel, KD; Laue, TM; Erickson, HP; McEver, RP

Published Date

  • September 15, 1997

Published In

Volume / Issue

  • 90 / 6

Start / End Page

  • 2381 - 2389

PubMed ID

  • 9310489

Pubmed Central ID

  • 9310489

International Standard Serial Number (ISSN)

  • 0006-4971

Language

  • eng

Conference Location

  • United States