X-ray Crystal Structures of Short Antimicrobial Peptides as Pseudomonas aeruginosa Lectin B Complexes

The paper X-ray Crystal Structures of Short Antimicrobial Peptides as Pseudomonas aeruginosa Lectin B Complexes has been published by ACS Chemical Biology.

Herein, we report X-ray crystal structures of 11–13 residue antimicrobial peptides (AMPs) active against Pseudomonas aeruginosa as complexes of fucosylated d-enantiomeric sequences with the P. aeruginosa lectin LecB. These represent the first crystal structures of short AMPs. In 24 individual structures of eight different peptides, we found mostly α-helices assembled as two-helix or four-helix bundles with a hydrophobic core and cationic residues pointing outside. Two of the analogs formed an extended structure engaging in multiple contacts with the lectin. Molecular dynamics (MD) simulations showed that α-helices are stabilized by bundle formation and suggested that the N-terminal acyl group present in the linker to the fucosyl group can extend the helix by one additional H-bond and increase α-helix amphiphilicity. Investigating N-terminal acylation led to AMPs with equivalent and partly stronger antibacterial effects compared to the free peptide.

Author(s): Stéphane Baeriswyl, Bee-Ha Gan, Thissa N. Siriwardena, Ricardo Visini, Maurane Robadey, Sacha Javor, Achim Stocker, Tamis Darbre, and Jean-Louis Reymond