Vascular Endothelial Growth Factor Receptor-1 (VEGFR-1), also known as Fms-like tyrosine kinase-1 (Flt-1), is a receptor tyrosine kinase that plays a crucial role in angiogenesis and vasculogenesis. It is part of the VEGF receptor family, which includes VEGFR-1, VEGFR-2, and VEGFR-3. These receptors are activated by binding to their respective ligands, the Vascular Endothelial Growth Factors (VEGFs), which are key regulators of blood vessel formation.
VEGFR-1 consists of an extracellular domain, a single transmembrane helix, and an intracellular tyrosine kinase domain. The extracellular domain is composed of seven immunoglobulin-like (Ig-like) domains, with the third domain (D3) being critical for ligand binding. The D3 domain of VEGFR-1 is responsible for high-affinity binding to VEGF-A, VEGF-B, and placental growth factor (PlGF).
VEGFR-1 acts primarily as a decoy receptor, sequestering VEGF ligands and preventing them from binding to VEGFR-2, which is the main mediator of angiogenic signaling. By modulating the availability of VEGF ligands, VEGFR-1 regulates angiogenesis and vascular permeability.
Recombinant VEGFR-1 D3 (Human, His Tag) is a truncated form of the receptor that includes the third Ig-like domain fused to a polyhistidine (His) tag. The His tag facilitates purification and detection of the recombinant protein using nickel affinity chromatography and anti-His antibodies, respectively.
The recombinant VEGFR-1 D3 is typically expressed in bacterial or mammalian expression systems. In bacterial systems, the gene encoding the D3 domain is cloned into an expression vector and transformed into Escherichia coli (E. coli) cells. The cells are then induced to produce the recombinant protein, which is subsequently purified using nickel affinity chromatography. In mammalian systems, the gene is transfected into Chinese hamster ovary (CHO) cells or other suitable cell lines, and the recombinant protein is secreted into the culture medium for purification.
Recombinant VEGFR-1 D3 is used in various research applications, including: