Efficient soluble expression and purification of influenza A and B nucleoproteins in E. coli

Abstract

ABSTRACT Viral nucleoprotein (NP) is an abundant essential protein of an influenza virus that has important functional and structural roles. It participates in genomic organization, nuclear trafficking, RNA transcription, and genome replication. From the research point of view, NP is an important protein that is used in the development of new diagnostic methods and vaccination protocols. NP is a promising target for antiviral chemotherapeutic drugs as well. Successful expression of codon-optimized NP genes in E. coli has been reported. In this study, we demonstrated the efficient expression and purification of soluble NPs of influenza A and B viruses in E. coli without the codon-optimization of DNA sequences. This procedure preserves the co-translational protein folding, protein configuration and function. Obtained NPs of influenza A and B viruses were monomers and reacted well with mouse specific antibodies according to Western blot analysis. Our results show that both influenza A and influenza B virus NPs can be efficiently expressed in E. coli without codon-optimization.