Functionally active VEGF fusion proteins.
Angiogenesis is stimulated by vascular endothelial growth factor (VEGF) acting via endothelial cell-specific receptors, such as VEGFR-2, that are overexpressed at the sites of angiogenesis. If VEGF retains activity as a fusion protein with a large N-terminal extension, it would facilitate development of VEGF-based vehicles for receptor-mediated delivery of therapeutic and diagnostic agents to the sites of angiogenesis. We have constructed, expressed in Escherichia coli, and purified VEGF fusion proteins containing a 158-amino acid N-terminal extension fused to human VEGF(121), VEGF(165), and VEGF(189). We report here that VEGF fusion proteins induce tyrosine autophosphorylation of VEGFR-2 and its downstream targets, as well as cell contraction in cells overexpressing VEGFR-2. Although N-terminal extensions decrease the affinity of VEGF fusion proteins to VEGFR-2, at saturating concentrations these proteins are as efficient as correct size VEGF(165). We hypothesize that VEGF fusion proteins may be employed for targeting endothelial cells at the sites of angiogenesis.
Backer
M V
MV
Sib Tech, Incorporated, 705 North Mountain Road, Newington, Connecticut 06111, USA. mbacker@sibtech.com
Backer
J M
JM
D000595:Amino Acid Sequence; D002461:Cell Line, Transformed; D048429:Cell Size / Q000187:drug effects; D015195:Drug Design; D016228:Endothelial Growth Factors / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology*; D006801:Humans; D008222:Lymphokines / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology*; D008969:Molecular Sequence Data; D010766:Phosphorylation / Q000187:drug effects; D011485:Protein Binding; D020033:Protein Isoforms / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism; D017978:Receptors, Growth Factor / Q000378:metabolism; D040262:Receptors, Vascular Endothelial Growth Factor; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D016228:Endothelial Growth Factors; D008222:Lymphokines; D020033:Protein Isoforms; D017978:Receptors, Growth Factor; D011993:Recombinant Fusion Proteins; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D020794:Receptor Protein-Tyrosine Kinases; D040262:Receptors, Vascular Endothelial Growth Factor