We investigated the antimicrobial activity of PD-L4, a type 1 RIP from Phytolacca dioica. We found that this protein is active on different bacterial strains both in a native and denatured/alkylated form and that this biological activity is related to a cryptic peptide, named PDL440-65, identified by chemical fragmentation. This peptide showed the same antimicrobial activity of full-length protein and possessed, similarly to several antimicrobial peptides, an immunomodulatory effect on human cells. It assumes an alpha-helical conformation when interact with mimic membrane agents as TFE and likely bacterial membranes are a target of this peptide. To date PDL440-65 is the first antimicrobial peptide identified in a type 1 RIP.
Keywords: Antimicrobial peptide; Cationic antimicrobial peptide; Phytolacca dioica; Ribosome inactivating protein.
Copyright © 2015 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.