Expression of a full-length influenza virus hemagglutinin in Escherichia coli

Abstract

Fusion or co-expression with other proteins is an effective option for improving recombinant protein expression in prokaryotic hosts. In this study, recombinant Escherichia coli strains expressing full-length influenza hemagglutinin (HA) were constructed to test the effect of co-expression of Cav1 protein or fusion with Oct1 upon expression of soluble HA. While HA alone was not expressed, a large amount of HA expression was observed upon co-expression with Cav1, which forms heterologous caveolae in the cytosol. When the DNA-binding protein Oct1 was used as a fusion partner, the HA solubility was improved. This study demonstrates a novel approach to achieve soluble expression of HA in E. coli.