CXCL4 / PF4 Protein

Platelet factor 4 (PF4), also known as chemokine (C-X-C motif) ligand 4 (CXCL4), is a small cytokine belonging to the CXC chemokine family. CXCL4/PF4 is released from the alpha-granules of activated platelets and binds with high affinity to heparin. Its major physiologic role appears to be neutralization of heparin-like molecules on the endothelial surface of blood vessels, thereby inhibiting local antithrombin III activity and promoting coagulation. As a strong chemoattractant for neutrophils and fibroblasts, CXCL4/PF4 probably has a role in inflammation and wound repair. This protein is released during platelet aggregation. CXCL4/PF4 neutralizes the anticoagulant effect of heparin because it binds more strongly to heparin than to the chondroitin-4-sulfate chains of the carrier molecule. CXCL4 is chemotactic for neutrophils and monocytes. It inhibits endothelial cell proliferation, the short form is a more potent inhibitor than the longer form. CXCL4/PF4 is up-regulated in human liver fibrosis and that it plays a nonredundant, functional role in experimental liver fibrosis by mediating stellate cell proliferation, migration, and intrahepatic immune cell recruitment.

Product Specifications

Synonyms

CXCL4 Protein; PF-4 Protein; SCYB4 Protein

Accession Number

NP_002610.1

Reactivity

Human

Cross Reactivity

Human

Assay Protocol

See Datasheet send with the product

Endotoxin

< 1.0 EU per μg of the protein as determined by the LAL method

Purity

> 90 % as determined by SDS-PAGE

Bioactivity

Measured by its ability to inhibit bFGF-dependent proliferation of human umbilical vein endothelial cells (HUVEC) . The ED50 for this effect is typically 1-5μg/mL in the presence of 5 ng/mL bFGF.

Length

Form

Lyophilized

Buffer

PBS, pH 7.4

Reconstitution

See Datasheet

Molecular Weight

7.8 kDa

Storage Conditions

Samples are stable for up to twelve months from date of receipt at -20°C to -80°C. Store it under sterile conditions at -20°C to -80°C. It is recommended that the protein be aliquoted for optimal storage. Avoid repeated freeze-thaw cycles.