Snake venom vascular endothelial growth factors (VEGFs) exhibit potent activity through their specific recognition of KDR (VEGF receptor 2).
Vascular endothelial growth factor (VEGF165) exhibits multiple effects via the activation of two distinct endothelial receptor tyrosine kinases: Flt-1 (fms-like tyrosine kinase-1) and KDR (kinase insert domain-containing receptor). KDR shows strong ligand-dependent tyrosine phosphorylation in comparison with Flt-1 and mainly mediates the mitogenic, angiogenic, and permeability-enhancing effects of VEGF165. Here we show the isolation of two VEGFs from viper venoms and the characterization of their unique biological properties. Snake venom VEGFs strongly stimulated proliferation of vascular endothelial cells in vitro. Interestingly, the maximum activities were almost twice that of VEGF165. They also induced strong hypotension on rat arterial blood pressure compared with VEGF165 in vivo. A receptor binding assay revealed that snake venom VEGFs bound to KDR-IgG with high affinity (Kd = approximately 0.1 nm) as well as to VEGF165 but did not interact with Flt-1, Flt-4, or neuropilin-1 at all. Our data clearly indicate that snake venom VEGFs act through the specific activation of KDR and show potent effects. Snake venom VEGFs are a highly specific ligand to KDR and form a new group of the VEGF family.
Department of Biochemistry, Meiji Pharmaceutical University, 2-522-1, Noshio, Kiyose, Tokyo 204-8588, Japan.
Yasuo
Y
Yamazaki
Koji
K
Takani
Hideko
H
Atoda
Takashi
T
Morita
D000595:Amino Acid Sequence; D000818:Animals; D004305:Dose-Response Relationship, Drug; D007700:Kinetics; D008024:Ligands; D008969:Molecular Sequence Data; D011485:Protein Binding; D017386:Sequence Homology, Amino Acid; D012910:Snake Venoms / Q000378:metabolism*; D012911:Snakes; D013997:Time Factors; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism*; D042442:Vascular Endothelial Growth Factors / Q000378:metabolism*; D014757:Viper Venoms / Q000378:metabolism*
D008024:Ligands; D012910:Snake Venoms; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D014757:Viper Venoms; C519402:vammin protein, Vipera ammodytes ammodytes; D040301:Vascular Endothelial Growth Factor Receptor-2