Recombinant expression of LFchimera antimicrobial peptide in a plant-based expression system and its antimicrobial activity against clinical and phytopathogenic bacteria

Antimicrobial peptides (AMPs) with their broad and selective antimicrobial activity and lowered risk of resistance development in microbial populations are promining as a new alternative candidate to conventional antibiotics. Plant-based expression systems can be employed as cost-effective and high scale-up capacity production hosts for recombinant expression of AMPs. LFchimera is a chimerical peptide containing LFcin and LFampin antimicrobial peptides of bovine lactoferrin, and it has stronger bactericidal activity. Here, the LFchimera sequence was codon-optimized for tobacco and fused with endoplasmic reticulum retention signals along with a CaMV 35S promoter and then transferred by agrobacterium-mediated transformation. The integration and expression of the transgene in tobacco plants were confirmed by polymerase chain reaction (PCR) and RT-PCR, respectively. Recombinant production of the peptide was confirmed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), and peptide functional activity was confirmed by the antibacterial evaluation of total protein extracts against various clinical and phytopathogenic bacteria. Finally, LFchimera peptide was partially purified using an affinity column, and the antibacterial activity was shown. Taken together, these results confirmed that tobacco can be utilized for the recombinant production of antimicrobial peptides such as LFchimera.