Expression of a recombinant extracellular fragment of human vascular endothelial growth factor receptor VEGFR1 in E. coli.

Human vascular endothelium growth factor receptor VEGFR1 is a type III fms-like tyrosine kinase with weakly pronounced tyrosine kinase function. The second and third IgG-like domains of the extracellular part of VEGFR1 act as "traps" for VEGF and are prospective candidates for antiangiogenic therapy of VEGF-dependent tumors. cDNA encoding extracellular Ig-like domains 2, 3, 4 of VEGFR1 was cloned in expressing vectors pET28a, pET32a, and pQE60. The recombinant protein was expressed in E. coli cells and purified by metal affinity chromatography. An expressing construction and a superproducer strain were created, allowing the production of high amounts of recombinant VEGFR1 extracellular fragment, needed for experimental in vivo antiangiogenic therapy.