Expression and purification of JC virus VP2 fusion protein and preparation of its polyclonal antibody / 中华传染病杂志

ABSTRACT

Objective To obtain the antigen and antibody of JC virus(JCV)VP2.Methods The JCV VP2 gene were amplified from a cerebrospinal fluid sample by polymerase chain reaction (PCR)and confirmed by sequencing.Then,the gene was cloned into plasmid pET32a(+)to construct recombinant prokaryotic expression vector pET-32a(+)-VP2.The recombinant plasmid was transformed into the competent E.coli BL21.Induced with isopropyl-β-D-1-1 thiogalactopyranoside (IPTG),E.coli BL21 were subsequently crushed by ultrasound.The gene expression in the supernatant was analyzed by Western blot.Thereafter,the expressed protein was purified by isoeleetric point method.The polyclonal antibody against JCV VP2 protein was obtained from the BALB/c mouse immunized with the purified protein.Results The VP2 fusion protein was expressed in the E.coli BL21.The recombinant fusion protein was expressed by IPTG induetion with relative molecular mass of 58.5×10~3.Sodium dodecyl sulphate-polyacrylamide gel electrophoresis(SDSPAGE)analysis showed that the expression level was highter after 6-10 h of IPTG induction.The recombinant protein had good antigenicity which was confirmed by BALB/c mice immunized with the protein.Conclusions The successful expression and purification of VP2 fusion protein and the antibody will be valuable for the study on the biological function of VP2 and JCV epidemiologieal investigation.