Platelet Factor 4, Human (PF4)
704.14 $
For reserch purpose only
Shipping cost plus VAT not included , delivery in 7-14 business days
Catalog No
USB-P4258-25D
Supplier
US Biologicals
Size
100 µg
Product Overview
Product Properties
Target Gene
Product Overview
| Description | Platelet factor-4 (PF-4) is a low molecular weight, heparin-binding protein which is secreted from agonist-activated platelets. PF-4 is localized within the platelet a-granule where its concentration ranges from 11.2-12.4ug per 109 platelets making it, on a molar basis, one of the most abundant proteins in the platelet. Since the relative concentration of PF-4 in platelets exceeds that of plasma by 280,000-fold, PF-4 levels in plasma have been utilized as a measure of platelet activation in vivo. PF-4 is secreted from platelets in complex with a high molecular weight, proteoglycan, carrier protein. Sedimentation equilibrium experiments have shown that in the absence of its proteoglycan carrier, the molecular weight of PF-4 is 27,000-29,000. Subsequent amino acid sequencing of PF-4 revealed a molecular weight of 7,800 indicating that native PF-4 is a homotetramer. Functionally, PF-4 neutralizes the anticoagulant activity of heparin in plasma. The heparin binding site within PF-4 is presumably located within the lysine-rich, COOH-terminal region of the molecule. Since soluble heparin is a therapeutic agent, the physiological significance of the anti-heparin activity of PF-4 is not known. However, by interacting with cell surface expressed heparin-like glycosaminoglycans on endothelial cells, PF-4 may exert its procoagulant effect. PF-4 binding to cell surface glycosaminoglycans may also be a mechanism through which PF-4 stimulates the release of histamine from basophils. The chemotactic activity of PF-4 toward neutrophils and monocytes has also been localized to the COOH-terminal, presumed heparin-binding domain of PF-4. While PF-4 is primarily a secreted protein, PF-4 binding sites on the platelet surface have been identified which may be important for platelet aggregation. Source: Human pF-4, from supernatant of thrombin-activated platelets. Molecular Weight: 29kD Isoelectric Point: 7.6 Specific activity: ~170 Units/mg Unit Definition: 1 unit will neutralize 1 IU of heparin in 1ml of normal plasma Storage and Stability: Aliquot to avoid repeated freezing and thawing and freeze at -70°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Aliquots are stable for at least 6 months. |
| Source Antigen | Supernatant of thrombin-activated platelets (human) |
| Reactivity | |
| Cross Reactivity | |
| Applications | |
| Molecular Weight | 29 |
Product Properties
| Storage | -70°C |
| Grade | Purified |
| Purity | Purified by Heparin-agarose affinity chromatography. ≥95% pure (SDS-PAGE). |
| Form | Supplied as a liquid in 25mM HEPES, 2M sodium chloride, pH 7.4. No preservative added. |
| Reactivity Life | 12 months |
| Note | For reserch purpose only |
Target Gene
NA
