Platelet Factor 4 Polyclonal Antibody – HRP Conjugated
Affinity’s Platelet Factor 4 Polyclonal Antibody – HRP Conjugated is the base level of our horseradish peroxidase conjugated Platelet Factor 4 antibodies. The purity of IgG is typically 90% and is provided in a solution of HEPES buffered saline containing 50% glycerol (v/v). The titre is essentially the same as the starting antiserum and each vial typically contains the amount of IgG recovered from one milliliter of antiserum however this IgG has been conjugated with Horseradish Peroxidase as an enzyme reporter. This Platelet Factor 4 Polyclonal Antibody – HRP Conjugated is generally intended for use as labeled primary antibodies in applications such as immunoassay and immunoblotting.
Product Code: SAPF4-HRP
Retail Product Size: 0.2mg vial
Host Animal: Sheep Anti-Human Platelet Factor 4 Polyclonal Antibody – HRP Conjugated
Species Cross Reactivity: View Chart
Description of Platelet Factor 4 (PF4)
Platelet Factor 4 (PF4) is a small high-affinity heparin binding protein localized in the α-granules of platelets and megacaryocytes. It is a member of a multigene “intercrine-cytokine” family that includes Beta-thromboglobulin, connective tissue activating peptide III, monocyte-derived neutrophil chemotactic factor and melanoma growth stimulatory factor. Human PF4 consists of 70 amino acids and has a mass of 7800 daltons. In the platelet, PF4 exists as a homo-tetramer in complex with a high-molecular weight proteoglycan carrier. PF4 is one of the most abundant proteins in the platelet alpha-granule and is considered platelet-specific, as its concentration in platelets is more than 20,000-fold greater than in plasma. The heparin neutralization activity of PF4 is believed to be due to the presence of four lysine residues interspersed among pairs of aliphatic residues in the C-terminal region of the molecule. During vessel injury, platelets are stimulated by thrombin or other agonists to release alpha-granule contents at the site of injury. Presumably the potent heparin neutralization activity of PF4 would reduce the anticoagulant activity of antithrombin, prolonging the action of thrombin and activated factor X to promote clot formation. Released PF4 also binds to heparin-like molecules on the surface of endothelial cells and hepatocytes, neutralizing the anticoagulant activity expressed by these cells. Some of the other activities attributable to PF4 include the potentiation of platelet aggregation, stimulation of fibroblast attachment to substrata, chemotactic activity with respect to neutrophils and inhibition of contact activation1,2.
References and Reviews
- Rucinski B, Niewiarowski S, Strzyzewski M, Holt JC, Mayo KH; Human Platelet Factor 4 and its C-Terminal Peptides: Heparin Binding and Clearance from the Circulation; Thrombosis and Haemostasis 63, pp 493-498, 1990.
- Biochemistry and Physiology of Secreted Platelet Proteins; in Hemostasis and Thrombosis, 3rd Edition, eds. RW Colman, J Hirsh, VJ Marder and EW Salzman, pp. 546-566, J.B. Lippincott Co., Philadelphia PA, USA, 1994.