Expression of extracellular domain of human vascular endothelial growth factor receptor-2 in Pichia pastoris.

OBJECTIVE: To investigate the feasibility of high expressing extracellular domain of human vascular endothelial growth factor receptor-2 (heVEGFR-2) with eukaryotic protein structure in Pichia pastoris. METHODS: We used PCR to amplify the DNA fragment encoding heVEGFR-2 from pORF-heVEGFR-2. The recombinant Pichia pastoris secretory expression vector(pPICZalphaA-heVEGFR-2)was constructed and transferred into Pichia pastoris X-33 by electroporation. The high expression transformnants were identified through its drug-resistant phenotype and methanol induction. RESULTS: As indicated by SDS-PAGE, the recombinant heVEGFR-2 protein with a molecular weight (MW) approximately 108 kDa, which reached 80 mg/L in the mass concentration, comprised 45% of the total expressed secreted proteins from Pichia pastoris X-33. The section of heVEGFR-2 had a MW approximately 106 kDa. The results of western blot analysis demonstrated that this protein could be specifically recognized by the rat monoclonal antibody against mouse VEGFR-2 (rat McAb against mVEGFR-2). CONCLUSION: The heVEGFR-2 with eukaryotic protein structure can get a high expression in Pichia pastoris.