Recombinant Orf Virus VEGF-E, His-Tag

Biomolecules

A DNA sequence encoding the mature variant of ovVEGF-E isolate D1701 (GenBank accession No. AF106020) was expressed in, E. coli, as a 132 amino acid residue fusion protein with an N-terminal His-tag sequence and a thrombin cleavage site. Recombinant VEGF-E homodimer was dimerized, in vitro, and has a predicted MW ca.35 kDa. Based on sequence similarity to VEGF-A, a gene encoding a VEGF homologue has recently been discovered in the genome of Orf virus (OV). Different isolates of Orf virus show significant amino acid sequence similarity to VEGF-A and described as a viral virulence factor that appears to be derived from captured host genes. All eight cysteine residues of the central cysteine knot motif characteristic of members of the VEGF family are conserved among other residues in the VEGF-E proteins. Alignment of all mammalian VEGF sequences indicated that VEGF-E is distinct from the previously described VEGFs but most closely related to VEGF-A. Like VEGF-A, VEGF-E was found to bind with high affinity to VEGF receptor-2 (KDR) resulting in receptor autophosphorylation, however in contrast to VEGF-A, VEGF-E can not bind to VEGF receptor-1 (Flt -1). Furthermore VEGF-E can also not bind to VEGF receptor-3 (FLT-4). VEGF-E is a potent angiogenic factor selectively binding to VEGF receptor-2/KDR.

Centrifuge vial prior to opening. The lyophilized VEGF-E is soluble in water and most aqueous buffers. The lyophilized VEGF-E should be reconstituted in PBS or medium containing at least 0.1% human or bovine serum albumin to a concentration not lower than 50.0 ug/ml.

Measured in a cell proliferation assay using primary HUVECs. The ED50 for this effect is typically 1-5 nglmL.