title: New insight into the mechanism of action of the temporin antimicrobial peptides.
abstract: Temporins constitute a family of amphipathic alpha-helical antimicrobial peptides (AMPs) and contain some of the shortest cytotoxic peptides, comprised of only 10-14 residues. We have recently investigated two members of this family, temporin A (TA) and temporin L (TL), because of their different spectra of antimicrobial activity and toxicity. Consequently, we developed new analogues with promising biological activities named Pro(3)-TL and Gln(3)-TA. In this work, we performed a detailed NMR analysis of the new analogues in SDS and DPC micelles, which mimic bacterial and mammalian membranes, respectively. NMR studies reveal that strongly hemolytic Gln(3)-TA was in a stable helical conformation along the entire sequence, while weakly hemolytic but antimicrobial Pro(3)-TL showed conformational averaging at the N-terminus. Furthermore, molecular dynamics (MD) simulations on TL and Pro(3)-TL were performed in explicit water and DPC micelles. Simulations indicated that both peptides prefer a location at the micelle-water interface; however, Phe(1) of strongly hemolytic TL was embedded more in depth into DPC, and only TL caused a significant distortion of the micelle shape. By combining NMR and computational analyses, we obtained a molecular-level resolution of the interactions between TL and its analogues with membrane mimicking micelles.
authors.affiliation: Department of Pharmaceutical and Toxicological Chemistry, University of Naples Federico II, I-80131 Naples, Italy.
authors.forename: Maria Rosaria
authors.initials: MR
authors.lastname: Saviello
authors.forename: Stefania
authors.initials: S
authors.lastname: Malfi
authors.forename: Pietro
authors.initials: P
authors.lastname: Campiglia
authors.forename: Andrea
authors.initials: A
authors.lastname: Cavalli
authors.forename: Paolo
authors.initials: P
authors.lastname: Grieco
authors.forename: Ettore
authors.initials: E
authors.lastname: Novellino
authors.forename: Alfonso
authors.initials: A
authors.lastname: Carotenuto
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology / Q000633:toxicity; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry* / Q000502:physiology / Q000633:toxicity; D005973:Glutamine / Q000737:chemistry; D006094:Gram-Positive Bacteria / Q000187:drug effects; D006461:Hemolysis / Q000187:drug effects; D009682:Magnetic Resonance Spectroscopy; D008567:Membranes, Artificial; D008823:Micelles; D010455:Peptides / Q000737:chemistry* / Q000502:physiology / Q000633:toxicity; D011392:Proline / Q000737:chemistry; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D011506:Proteins / Q000737:chemistry* / Q000502:physiology / Q000633:toxicity; D011896:Rana temporaria; D013329:Structure-Activity Relationship
chemical_list: D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D008567:Membranes, Artificial; D008823:Micelles; D010455:Peptides; D011506:Proteins; C104501:temporin; C469676:temporin L, Rana temporaria; D005973:Glutamine; D011392:Proline