• Purity

  >95%, by SDS-PAGE under reducing conditions and visualized by silver stain

• Endotoxin Level

  <0.10 EU per 1 μg of the protein by the LAL method.  

• Activity

  Measured by its binding ability in a functional ELISA. Serially diluted Recombinant Human (rh) VEGF    _165b is added to a Recombinant Human VEGF R2/KDR/Flk?1 Fc Chimera (Catalog # ) coated plate (2 μg/mL, 100 μL/well). Bound rhVEGF    _165b is detected by a human VEGF    _165b specific antibody (Catalog # ). The concentration of rhVEGF    _165b that produces half-maximum response is approximately 0.12-0.6 nM.

• Source

  Spodoptera frugiperda,     Sf 21 (stably transfected)-derived Ala27-Asp191

• Accession #

• N-terminal Sequence    
  Analysis

  Ala27

• Structure / Form

  Disulfide-linked homodimer

• Predicted Molecular Mass

  19.1 kDa (monomer)

• SDS-PAGE

  20-21 kDa, reducing conditions

Carrier Free

What does CF mean?

CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our recombinant proteins. Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant protein to be stored at a more dilute concentration. The carrier free version does not contain BSA.

What formulation is right for me?

In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or as an ELISA standard. In contrast, the carrier free protein is recommended for applications, in which the presence of BSA could interfere.

Background: VEGF

Vascular endothelial growth factor (VEGF or VEGF-A), also known as vascular permeability factor (VPF), is a potent mediator of both angiogenesis and vasculogenesis in the fetus and adult (1-3). It is a member of the PDGF family that is characterized by the presence of eight conserved cysteine residues and a cystine knot structure (4). Humans express two sets of alternately spliced isoforms of 121, 145, 165, 183, 189, and 206 amino acids (aa) in length (4). VEGF₁₆₅ appears to be the most abundant and potent of the angiogenic isoform set, followed by VEGF₁₂₁ and VEGF₁₈₉ (3, 4). The anti-angiogenic or “b” set of isoforms is differentially spliced to contain six alternate amino acids at the C-terminus, and are the more highly expressed isoforms in normal adult tissue (5). VEGF_165b, like VEGF₁₂₁ but unlike most angiogenic isoforms, does not bind heparins and is therefore diffusible (4, 6). Human VEGF_165b shares 88% aa sequence identity with corresponding regions of mouse and rat, 96% with porcine, 95% with canine, and 93% with feline, equine and bovine VEGF_165b, respectively. VEGFs bind the type I transmembrane receptor tyrosine kinases VEGF R1 (also called Flt-1) and VEGF R2 (Flk-1/KDR) on endothelial cells (4). Although VEGF affinity is highest for binding to VEGF R1, VEGF R2 appears to be the primary mediator of VEGF angiogenic activity (3, 4). The affinity of VEGF_165b for VEGF R2 is similar to that of VEGF₁₆₅, but VEGF_165b only partially activates VEGF R2 such that the kinase regulatory site Y1054 is not phosphorylated (6). VEGF_165b also does not bind neuropilin-1, suggesting that the functional difference between VEGF₁₆₅ and VEGF_165b maybe due to either the lack of neuropilin-1 co-signaling or unique downstream signaling activated by VEGF_165b (8). Since VEGF_165b may compete with angiogenic VEGFs for VEGF R2 sites, its ectopic expression in tumors has been shown to inhibit their growth (7).

• References:

1. Leung, D.W. et al. (1989) Science 246:1306. 

2. Keck, P.J. et al. (1989) Science 246:1309. 

3. Byrne, A.M. et al. (2005) J. Cell. Mol. Med. 9:777. 

4. Robinson, C.J. and S.E. Stringer (2001) J. Cell. Sci. 114:853.

5. Nowak, D.G. et al. (2008) J. Cell Sci. 121:3487.

6. Kawamura, H. et al. (2008) Cancer Res. 68:4683.

7. Rennel, E.S. et al. (2008) Br. J. Cancer 98:1250.

8. Harper S.J. and Bates D.O. (2008) Nat. Rev. Cancer 8(11):880.

• Long Name:

  Vascular Endothelial Growth Factor

• Entrez Gene IDs:

  7422 (Human); 22339 (Mouse); 83785 (Rat); 281572 (Bovine); 403802 (Canine); 493845 (Feline); 30682 (Zebrafish)

• Alternate Names:

  MVCD1; VAS; vascular endothelial growth factor A; Vascular permeability factor; Vasculotropin; VEGF; VEGFA; VEGF-A; VEGFMGC70609; VPF; VPFvascular endothelial growth factor