New positions for peptide presentation in Potato virus X capsid protein

Abstract

Potato virus X (PVX) is widely used as a peptide presentation system in plant biotechnology, mostly for transient expression of desired peptides fused to the N-terminus of its capsid protein (CP). Here we describe testing/investigation of new positions for peptide presentation based on seven putative surface loops of PVX CP. We performed bacterial expression of fourteen different PVX CPs modified by the insertion of the epitope derived from the E7 oncoprotein (E7 epitope) of Human papillomavirus type 16 fused with His tag. The expression from vector pMPM-A4Ω in Escherichia coli MC1061 was performed to evaluate the capacity of the PVX CP platform to tolerate the insertion of E7 epitope fused with His tag in the seven putative surface loops. The immunological characteristics of expressed epitopes were assessed by Western blot using both anti-PVX CP and anti-His antibodies and by immunoelectron microscopy.

Keywords

• Bacterial expression
• Potato virus X
• Human papillomavirus
• E7 oncoprotein