|Cat. No. :
||The Angiopoietin (Ang) family of growth factors includes four members, all of which bind to the endothelial receptor tyrosine kinase Tie2. Two of the Angs, Ang-1 and Ang-4, activate the Tie2 receptor, whereas Ang-2 and Ang-3 inhibit Ang-1-induced Tie2 phosphorylation. Angiopoietin-1 (Ang-1) is a secreted growth factor which binds to and activates the Tie-2 receptor tyrosine kinase. The factor enhances endothelial cell survival and capillary morphogenesis, and also limits capillary permeability. Ang-2 binds the same receptor but fails to activate it: hence, it is a natural inhibitor of Ang-1. Ang-2 destabilizes capillary integrity, facilitating sprouting when ambient vascular endothelial growth factor (VEGF) levels are high, but causing vessel regression when VEGF levels are low. Tie-1 is a Tie-2 homologue but its ligands are unknown. Angiopoietin and Tie genes are expressed in the mammalian metanephros, the precursor of the adult kidney, where they may play a role in endothelial precursor growth. Tie-1-expressing cells can be detected in the metanephros when it first forms and, based on transplantation experiments, these precursors contribute to the generation of glomerular capillaries. During glomerular maturation, podocyte-derived Ang-1 and mesangial-cell-derived Ang-2 may affect growth of nascent capillaries.
||mouse NSO cells.
|Analysis Note :
||The biological activity is measured by its ability to inhibit serum deprivation induced apoptosis in HUVE cells.
|Biochem/physiol Actions :
||Ang-1 is a ligand with affinity to the Tie-2 receptor tyrosine kinase, which is expressed in early hematopoietic and endothelial cells. Both Ang-1 and Tie-2 play critical roles in embryonic angiogenesis as well as adult vascular integrity.
|Physical Form :
||Lyophilized from a 0.2 μm filtered solution in 50 mM Tris and 0.5 M sodium chloride, pH 6.5, containing 50 μg bovine serum albumin per 1 μg of cytokine.
|Storage Temp :
||Hemostasis; Signaling in Immune system