Differential expression of influenza N protein and neuraminidase antigenic determinants in Escherichia coli

Abstract

Two influenza gene products of similar size and codon usage have been expressed in Escherichia coli under control of the phage λ p R promoter. The influenza N protein (NP) was expressed in its entirety after fusion to a short (12 amino acid) segment of the λ cro gene product and constituted about 1–2% of total soluble cell protein after induction. By contrast, constructions using the full length neuraminidase (NA) gene failed to give rise to detectable amounts of NA antigen after fusion to either the 12 amino acid Cro peptide or after fusion to bacterial β-galactosidase (βgal). Rather, expression of NA antigenic determinants was only achieved after deletion of coding sequences at the 3' end of the βgal-NA fusion construct such that the encoded protein precipitated within the cell.