Solid-state NMR and simulation studies of equinatoxin II N-terminus interaction with lipid bilayers

Abstract

The interaction with model membranes of a peptide, EqtII1-32) corresponding to the N-terminal region of the pore-forming toxin equinatoxin II (EqtII) has been studied using solid-state NMR and molecular dynamics (MD) simulations. The distances between specifically labeled nuclei in [ 19F-para]Phe16-[1-13C]Leu19 and [19F-para] Phe16-[15N]Leu23 analogs of EqtII1-32 measured by REDOR in lyophilized peptide were in agreement with published crystal and solution structures. However, in both DMPC and mixed DMPC:SM membrane environments, significant changes in the distances between the labeled amino acid pairs were observed, suggesting changes in helical content around the experimentally studied reg..