Effect of hydrophobic moment on membrane interaction and cell penetration of apolipoprotein E-derived arginine-rich amphipathic α-helical peptides

Abstract

We previously developed an amphipathic arginine-rich peptide, A2-17, which has high ability to directly penetrate across cell membranes. To understand the mechanism of the efficient cell-penetrating ability of the A2-17 peptide, we designed three structural isomers of A2-17 having different values of the hydrophobic moment and compared their membrane interaction and direct cell penetration. Confocal fluorescence microscopy revealed that cell penetration efficiency of peptides tends to increase with their hydrophobic moment, in which A2-17 L14R/R15L, an A2-17 isomer with the highest hydrophobic moment, predominantly remains on plasma cell membranes. Consistently, Trp fluorescence analysis indicated the deepest insertion of A2-17 L14R/R15L into lipid membranes among all A2-17 isomers. Electrophysiological analysis showed that the duration and charge flux of peptide-induced pores in lipid membranes were prominent for A2-17 L14R/R15L, indicating the formation of stable membrane pores. Indeed, the A2-17 L14R/R15L peptide exhibited the strongest membrane damage to CHO-K1 cells. Atomic force microscopy quantitatively defined the peptide-induced membrane perturbation as the decrease in the stiffness of lipid vesicles, which was correlated with the hydrophobic moment of all A2-17 isomers. These results indicate that optimal membrane perturbation by amphipathic A2-17 peptide is critical for its efficient penetration into cells without inducing stabilized membrane pores.

Antimicrobial Peptide Mastoparan-AF Kills Multi-Antibiotic Resistant Escherichia coli O157:H7 via Multiple Membrane Disruption Patterns and Likely by Adopting 3–11 Amphipathic Helices to Favor Membrane Interaction

“…It is known that a helical structure is required for the activities of mastoparans [ 17 , 19 ]. A previous study has indicated that a synthetic amphipathic peptide isomer with the highest hydrophobic moment than the other isomers presents with the best membrane interaction ability and forms stable membrane pores with the strongest membrane damage [ 49 ]. Therefore, based on our physicochemical analysis results, it is feasible that mastoparan-AF, -A, -B, -D, -M, and -V may adopt dynamically favorable 3–11 helix structures (instead of α-helix) to facilitate membrane interaction, and thereby result in membrane disruption on the surface of bacteria.…”

Evaluation of a Novel Synthetic Peptide Derived from Cytolytic Mycotoxin Candidalysin

“…The amino acid changes caused by the definition of amphipathicity provoke the rearrangement of the hydrophobic moment, increasing when compared to candidalysin. The increase of hydrophobic moment tends to be correlated to higher efficacy of cell binding and penetration [ 36 , 37 , 38 ].…”

Cell Penetrating Peptides: Classification, Mechanisms, Methods of Study, and Applications

“…Discriminate between internalization within lipid bilayer or surface [170][171][172][173][174][175][176][177][178][179] Electron Microscopy Peptide distribution and membrane modification induced by the peptide.…”

“…[6,170] One such study, that compared the membrane interaction with hydrophobic properties and amphipathicity of the peptides, showed that cell penetration efficiency tends to increase with their α-helical and amphipathicity content, but, with the highest hydrophobic moment, CPPs predominantly remain on plasma cell membranes. [171] Another group has explored the neuroprotective effects of two arginine rich CPPs, containing TAT fragments, by CD experiment aimed to characterize the interaction of these peptides with an artificial neuronal membrane. Modification in the intensity of the peptide CD signal in combination with the redshift effect was symptomatic of the formation of ordered structures during the interaction with neuronal mimicking liposomes.…”