鹌鹑血管内皮生长因子受体Quek1胞外段第2～4 区cDNA在毕赤酵母中的表达和鉴定

以PCR法从携带有鹌鹑血管内皮生长因子受体quek1(qVEGFR)的质粒中扩增获得qVEFR胞外段第2～4区cDNA片段,并将其定向克隆到毕赤酵母表达载体pPICZαA中,获得重组表达质粒pPICZαA-qVEGFR2.然后将用SacI酶线性化的pPICZαA-qVEGFR2质粒电转化到毕赤酵母菌GS115中,经Zeocin抗性和PCR筛选得到阳性重组菌株.重组菌株用甲醇进行诱导表达后,通过SDS-PAGE和Western blot分析鉴定蛋白表达产物,结果证实qVEGFR2胞外段第2～4区cDNA在毕赤酵母中获得了分泌性表达,为进一步研究和制备肿瘤蛋白疫苗打下了基础.

Expression of Quail Vascular Endothelial Growth Factor Receptor Quek-1 Extracellular Domain 2-4 Loop Cdna in Pichia pastoris

The extracellular domain 2-4 loop cDNA of quail vascular endothelial growth factor receptor quek1 (qVEGFR2) was obtained from plasmid carrying qVEGFR2 by PCR. Then it was cloned into expression vector pPICZalphaA of Pichia pastoris. To construct recombinant expression plasmid pPICZalphaA-qVEGFR2, linearized pPICZalphaA-qVEGFR2 with SacI was transformed to electroporated Pichia pastoris GS115. Subsequently, positive clone was selected by PCR and its phenotype was determined. SDSPAGE and Western blot assays of culture medium from a methanol-induced expression strain demonstrated that recombinant qVEGFR2 proteins were expressed and secreted into the culture medium. These results could provide a basis for further researches on tumor protein vaccine as well as for the preparation of tumor protein vaccine with Pichia pastoris.