1 research outputs found
Revisiting Peptide Amphiphilicity for Membrane Pore Formation
It has previously been shown that an amphipathic de novo
designed peptide made of 10 leucines and four phenylalanines substituted
with crown ethers induces vesicle leakage without selectivity. To
gain selectivity against negatively charged dimyristoylphosphatidylglycerol
(DMPG) bilayers, one or two leucines of the peptide were substituted
with positively charged residues at each position. All peptides induce
significant calcein leakage of DMPG vesicles. However, some peptides
do not induce significant leakage of zwitterionic dimyristoylphosphatidylcholine
vesicles and are thus active against only bacterial model membranes.
The intravesicular leakage is induced by pore formation instead of
membrane micellization. Nonselective peptides are mostly helical,
while selective peptides mainly adopt an intermolecular Ī²-sheet
structure. This study therefore demonstrates that the position of
the lysine residues significantly influences the secondary structure
and bilayer selectivity of an amphipathic 14-mer peptide, with Ī²-sheet
peptides being more selective than helical peptides