Human Angiopoietin-1 (Recombinant)

Recombinant Human Angiopoietin-1 (ANG-1)

Source: Insect Cells

Background: 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 destabilises 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. After birth, vasa rectae acquire their mature configuration and Ang-2 expressed by descending li mbs of loops of Henle would be well placed to affect the growth of this medullary microcirculation. Finally, preliminary data implicate angiopoietins in deregulated vessel growth in Wilms\' kidney tumours and in vascular remodelling after nephrotoxicity. A ltogether, existing data suggest that VEGF-A and Angiopoietins not only have quite different roles during vascular development, but also very complementary and coordinated roles.

Description: Recombinant Human Angiopoitin-1 (Ang-1), a 66 kDa protein consisting of 476 amino acid residues (21-496), is fused to a N-terminal myc-tag and produced in insect cells.

Physical Appearance: Sterile Filtered White lyophilized (freeze-dried) powder.

Formulation: The protein contains 50mM Tris-HCL, pH 7.5, 150mM NaCl, 0.05% CHAPS and BSA.

Stability: ANG-1 although stable at 140C 1 week, should be stored desiccated below -180C. Please avoid freeze-thaw cycles.

Purity: Greater than 95.0% as determined by: (a) Analysis by RP-HPLC. (b) Anion-exchange FPLC. (c) Analysis by reducing and non-reducing SDS-PAGE Silver Stained gel.

Amino acid sequence: The sequence of the first five N-terminal amino acids was determined and was found to be Ser-Leu-Gly-Ser-Leu.

Dimers and aggregates: Less than 1% as determined by silver-stained SDS-PAGE gel analysis.

Biological Activity: The biological activity was determined by the induction of endothelial cell sprouting as described in Korff et al., 2001.

Endotoxin: Less than 0.1 ng/ g (IEU/ g) of Recombinant Human ANG-1.

Protein content: Protein quantitation was carried out by two independent methods: 1. UV spectroscopy at 280 nm using the absorbency value of 1.27 as the extinction coefficient for a 0.1% (1mg/ml) solution. This value is calculated by the PC GENE computer analysis program of protein sequences (IntelliGenetics). 2. Analysis by RP-HPLC, using a standard solution of ANG-1 as a Reference Standard.

Usage: BioWORLD\'s products are furnished for LABORATORY RESEARCH USE ONLY. The product may not be used as drugs, agricultural or pesticidal products, food additives or household chemicals.