Investigating the effect of the inhibitory peptide on L.monocytogenes cell invasion: an in silico and in vitro study.

AIMS: L.monocytogenes monocytogenes is an omnipresent bacterium that causes a fatal food-borne illness, listeriosis. The connection of this bacterium to E-cadherin through internalin A plays a significant role in the internalization of the bacteria. In this study, this interaction has been investigated for the design of an inhibitory peptide.

METHODS

The interaction of the proteins involved in the entry of bacteria was evaluated by molecular docking. According to their interactions, an inhibitory peptide was designed to bind to internalin A by server peptiderive. Its effects on L.monocytogenes invasion on the Caco-2 cell line and biofilm formation were also assessed.

FINDINGS: Docking results showed that the peptide has a high affinity for binding to Internalin A. The synthesized peptide at a concentration of 64 µg/ml inhibited 80% of the invasion of L.monocytogenes into the Caco-2 cell line. Furthermore, the studied peptide at the highest concentration had a slight inhibitory effect on biofilm formation.

CONCLUSION

These results reveal that short polypeptides can impede the invasion of target cells by L. monocytogenes in vitro and could be advantageous as restoring agents in vivo.