Stable isotope-assisted NMR characterization of interaction between lipid A and sarcotoxin IA, a cecropin-type antibacterial peptide.
Related Articles Stable isotope-assisted NMR characterization of interaction between lipid A and sarcotoxin IA, a cecropin-type antibacterial peptide.
Biochem Biophys Res Commun. 2013 Feb 8;431(2):136-40
Authors: Yagi-Utsumi M, Yamaguchi Y, Boonsri P, Iguchi T, Okemoto K, Natori S, Kato K
Abstract
Sarcotoxin IA is a 39-residue cecropin-type peptide from Sarcophaga peregrina. This peptide exhibits antibacterial activity against Gram-negative bacteria through its interaction with lipid A, a core component of lipopolysaccharides. To acquire detailed structural information on this specific interaction, we performed NMR analysis using bacterially expressed sarcotoxin IA analogs with (13)C- and (15)N-labeling along with lipid A-embedding micelles composed of dodecylphosphocholine. By inspecting the stable isotope-assisted NMR data, we revealed that the N-terminal segment (Leu3-Arg18) of sarcotoxin IA formed an amphiphilic ?-helix upon its interaction with the aqueous micelles. Furthermore, chemical shift perturbation data indicated that the amino acid residues displayed on this ?-helix were involved in the specific interaction with lipid A. On the basis of these data, we successfully identified Lys4 and Lys5 as key residues in the interaction with lipid A and the consequent antibacterial activity. Therefore, these results provide unique information for designing chemotherapeutics based on antibacterial peptide structures.
PMID: 23313507 [PubMed - indexed for MEDLINE]
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