Expression Of HEV Gene ORF2 Fragment In Escherichia Coli

To obtain HEV antigen protein of immune activity, optimum expression methods of HEV antigen protein gene used in E.coli was discussed in this paper, which was the foundation of HEV gene engineer vaccine.Firstly, we used the methods of CaCl₂ to transform the plasmid vector pTO-T7-E cloned HEV antigen protein gene into E.coli BL21(DE3). The single clone bacteria screened by anti-kanamycin quality were cultured and the plasmids were extracted. Transforming bacteria were identified by enzyme chopping and PCR. Secondly, under the different temperature of 25°C,30°C,37°C respectively, transforming bacteria were cultured, induced and sonicate disrupted. By SDS-PAGE, target protein was detected and its immune activity was assayed through western blot.SDS-PAGE results showed that under the temperature of 37°C, the molecular weight of recombinant protein in E.coli induced by IPTG was about 21KDa, which was integrated with theory value. We can also give an conclusion that expression products existed in the form of inclusion body in the cell. Meanwhile, the immune activity of the target protein were proved through western blot in the end.