Research of the E. coli expressed major capsid proteins from Noroviruses with different genotypes collected in Beijing area / 中华微生物学和免疫学杂志

ABSTRACT

Objective To obtain the specific antigens of the expressed major capsid proteins from Noroviruses with different sub-genotypes in Beijing area. Methods The full-length genes of the major capsid proteins (VP1)were obtained through the amplification of the VP1 encoding gene in the recombinant plasmids pBST-CR2987(G Ⅱ-3)and pBST-CR2932(GⅡ-4),which represented different Norovirus geno-types. The full-length genes were sub-cloned into the expression vector pET-30a(+),resulting in a recombinant plasmid, with which the BL21 competent cells were transformed, and the expression of the gene was induced by adding IPTG to the growth culture. The expression of the major capsid proteins were analyzed with Coomassie blue staining after SDS-PAGE, and assayed by Western blot with serum from human. Results (1)The major capsid protein genes of CR2987 and CR2932 were sub-cloned into expression vector pET-30a(+). The VP1 encoding genes were 1647 bp in length for CR2987 and 1623 bp for CR2932. The open reading frames(ORF)coded for 549 and 541 amino acids for these two proteins, respectively. (2)The expressed VP1s were present primarily as inclusion bodies,and the maximal amount of the expressed proteins occurred at 4-6 h after IPTG induction.(3)These VP1s could be recognized by specific immune serum against VP1 of Norovirus as well as His-tag antibody. Conclusion The VP1s of CR2987 and CR2932 are expressed in BL21 E.coli cells.The expressed VP1s could react with specific immune serum against VP1 of Norovirus, indicating that the expressed VP1s are of antigenicity.