Orientation of the antimicrobial peptide, cecropin A-magainin 2 hybrid, in a lipid bilayer studied by 15N solid-state NMR

The orientation of cecropin A-maganin A (CAMA) peptide in lipid bilayers was determined from the 15N CAS obtained from 15 solid-state nuclear magnetic resonance (NMR) experiments. The structure of CAMA and its analogues bound to dodecylphosphocholine (DPC) micelles was determined by solution NMR spectroscopy. CAMA and lipid at a 1:10 molar ratio were dissolved in methanol/chloroform. CAMA has seven lysine residues, and is therefore likely to bind electrostatically to the negative charged membrane surface. CAMA has hydrophobic amino acids, Trp2, Phe5, Phe 14 and Phe20, and the bulky hydrophobic side chains of which interact with the lipid acyl chain region.