Inadvertent expression of dengue 2 virus NS3-EGFP fusion protein in Escherichia coli using the pEGFP-N1 mammalian expression vector

Abstract

Dengue 2 New Guinea C (NGC) virus NS3 protein, a potentially important virulence factor was cloned to the N-terminus of the Aequoreo t.rictorio enhanced green fluorescent protein (EGFP) using the pEGFP-N1 manimaiian expression vector. During amplification of the recombinant plasmid in E. coli, transformants expressing the EGFI' were detected in vivo when viewed using fluorescence microscopy. This inadvertent expression of the recombinant fusion protein was confirmed further by detection of the T7-Tag peptide cloned to the amino terminal of the fusion protein using T7-Tag specific monoclonal antibody. These findings represent perhaps the first reported expression of the T7-Tag-N53-EGFP fusion protein using the pEGFP-N1 mammalian expression vector in E. coli.