Characterization of the Structure and Membrane Interaction of the Antimicrobial Peptides Aurein 2.2 and 2.3 from Australian Southern Bell Frogs

ABSTRACT

The structure and membrane interaction of the antimicrobial peptide aurein 2.2 (GLFDIVKKVVGALGSL-CONH^sub 2^), aurein 2.3 (GLFDIVKKVVGAIGSL-CONH^sub 2^), both from Litoria aurea, and a carboxy C-terminal analog of aurein 2.3 (GLFDIVKKVVGAIGSL-COOH) were studied to determine which features of this class of peptides are key to activity. Circular dichroism and solution-state NMR data indicate that all three peptides adopt an α-helical structure in the presence of trifluoroethanol or lipids such as 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and a 1:1 mixture of DMPC and 1,2-dimyristoyl-snglycero-3-[phospno-rac-(1-glycerol)] (DMPG). Oriented circular dichroism was …