Recombinant Human Endogenous VEGFR-1, soluble

Lyophilized protein is stable for 6 months at -20C to -80C. Store reconstituted protein in working aliquots at -20C. Avoid repeated freeze-thaw cycles.

Recombinant Human soluble VEGFR1 is the naturally occurring form and was cloned from total RNA of human uMbilical vein endothelial cells. The recombinant mature soluble VEGFR1 is a glycosylated monomeric protein with a mass of approximately 96 kDa consisting of the first 6 extracellular domains (Met1-His688) and containing 31 unique amino acid residues at the C-terminus. Endothelial cells express three different vascular endothelial growth factor (VEGF) receptors, belonging to the family of receptor tyrosine kinases (RTKs). They are named VEGFR1 (FLT1), VEGFR2 (KDR/FLK1), and VEGFR3 (FLT4). Their expression is almost exclusively restricted to endothelial cells, but VEGFR1 can also be found on monocytes, dendritic cells and on trophoblast cells. The receptor contains seven immunoglobulin-like extracellular domains, a single transmembrane region and an intracellular split tyrosine kinase domain. Compared to VEGFR2 the FLT1 receptor has a higher affinity for VEGF but a weaker signaling activity. VEGFR1 thus leads not to proliferation of endothelial cells, but mediates signals for differentiation. Interestingly, a naturally occuring soluble variant of VEGFR1 (sVEGFR1) was found in HUVEC supernatants in 1996, which is generated by alternative splicing of the FLT1 mRNA. The biological functions of sVEGFR1 still are not clear, but it seems to be an endogenous regulator of angiogenesis, binding VEGF with the same affinity as the full length receptor.

Centrifuge vial prior to opening. Soluble in water and most aqueous buffers. Add PBS to the vial to fully solubilize the protein to a concentration not lower than 100 ng/ml.

< 0.1 ng/ug of VEGFR1