Construction and expression of a recombinant immunotoxin against human glioma, SZ39(ScFv)-PE40

Objective To construct the gene of recombinant immunotoxin SZ39(ScFv) PE40 and express it in E.coli. Methods The cDNA encoding PE40 was amplified by PCR in which the plasmid pVC85 served as template, then the PE40 gene was attached to SZ39 ScFv gene to construct the SZ39(ScFv) PE40 gene, and then it was inserted into expression vector pET20b(+). The expression of SZ39(ScFv) PE40 was induced by IPTG in E.coli BL21(DE3)pLysS. Results SDS PAGE showed a novel protein band with an anti~cipated molecular mass of 68kD, which could also be determined by Western blot assay. Scanning of SDS PAGE gel showed that the expressed protein accounted for 20% of the total bacterial protein, it existed in the form of inclusion body. Conclusion The recombinant immunotoxin SZ39(ScFv) PE40 can be highly expressed in E.coli BL21(DE3)pLysS via expression vector pET20b(+) in the form of inclusion body.