Vascular Endothelial Growth Factor A164 (VEGF-A164), a member of the cysteine knot growth factor[1], is one of major isoforms of VEGF-As. VEGF-As are endothelial cell-specific mitogens with angiogenic and vascular permeability-inducing properties[2]. During maturation, rat VEGF-A is alternatively spliced to generate rVEGF-A120, rVEGF-A164 and rVEGF-A188[3] which correspond to hVEGF-A121, hVEGF-A165 and hVEGF-A189 in human, respectively (the numbers designate the amino acid residues).  The active form of rVEGF-A164 is either a homodimeric or heterodimeric polypeptides which bind to the transmembrane tyrosine kinases receptors FLT1, FLK1 or KDR[4] or to the non-tyrosine kinase neuropilin receptors NRP1/2[5].

Recombinant rat Vascular Endothelial Growth Factor A164 (rrVEGF-A164) produced in P. pastoris is a disulfide-linked homodimer containing two polypeptide chains of 165 amino acids each. A fully biologically active molecule, rrVEGF-A164 has a molecular mass of 38 kDa analyzed by non-reducing SDS-PAGE and is obtained by chromatographic techniques at ExCell Bio.