利用SUMO融合系统高效表达可溶性重组蛋白的研究

利用pSUMO表达载体在大肠杆菌中高效可溶性表达若干种外源蛋白,如鼠源成纤维细胞生长因子(FGF)-21、人源FGF-21、人源白细胞介素(IL)-1β,并与pET-30a(+)及pTYB11表达系统作比较。将鼠源FGF-21、人源FGF-21及人源IL-1β基因分别亚克隆至pSUMO表达载体上,在大肠杆菌Rosetta(DE3)中诱导表达,并用镍离子螯合柱(Ni-NTA)纯化重组蛋白,透析后利用SUMO蛋白酶I切割融合蛋白,获得纯度较高的成熟蛋白。上述基因在pET-30a(+)及pTYB11中表达量极低,考马斯亮蓝染色几乎检测不到。在pSUMO表达体系中这些基因均以可溶形式表达,且可被SUMO蛋白酶I有效的切割,获得纯度较高的成熟蛋白。上述蛋白可在pSUMO表达系统中获得高效可溶性表达。

Efficient expression of several recombinant proteins by pSUMO expression vector

The objective of the paper is to utilize pSUMO expression vector to efficiently express several recombinant proteins in E.coli system,including mouse fibroblast growth factor(FGF)-21,human FGF-21 and human interleukin(IL)-1β,in comparison with pET-30a(+) and pTYB11 expression systems.The genes of mouse FGF-21,human FGF-21 and human interleukin(IL)-1β were subcloned into the pSUMO expression vector.The recombinant plasmids were transformed into Escherichia coli Rosetta(DE3) and the expressed recombinant proteins were purified by His binding column.The purified recombinant proteins were dialyzed against PBS.The fusion proteins could be efficiently cleaved by SUMO protease-Ⅰto obtain pure and active recombinant proteins.Expression level of these genes was very low in pET-30a(+) and pTYB11 expression systems and could not be detected by Coomassie blue staining.However,all these cDNAs were expressed in soluble form and the recombinant proteins accounted for 30%-50% of total bacterial proteins in the SUMO expression system.The pSUMO expression vector can efficiently express soluble recombinant proteins.