Secondary structure of cell-penetrating peptides controls membrane interaction and insertion

Abstract

The clinical use of efficient therapeutic agents is often limited by the poor permeability of the biological membranes. In order to enhance their cell delivery, short amphipathic peptides called cell-penetrating peptides (CPPs) have been intensively developed for the last two decades. CPPs are based either on protein transduction domains, model peptide or chimeric constructs and have been used to deliver cargoes into cells through either covalent or non-covalent strategies. Although several parameters are simultaneously involved in their internalization mechanism, recent focuses on CPPs suggested that structural properties and interactions with membrane phospholipids could play a major role in the cellular uptake mechanism. In the present work, we report a comparative analysis of the structural plasticity of 10 well-known CPPs as well as their ability to interact with phospholipid membranes. We propose a new classification of CPPs based on their structural properties, affinity for phospholipids and internalization pathways already reported in the literature.

Surface Physical Activity and Hydrophobicity of Designed Helical Peptide Amphiphiles Control Their Bioactivity and Cell Selectivity

“…Over 50% of the active ACPs are physically surface active, suggesting that amphipathicity is a key driver of the membrane interactions for these peptides. 4 As the air/water interface constitutes a useful model to investigate the interfacial affinity of peptides, 33,34 we have compared the adsorption properties of the peptides at this interface. Helical Structure.…”

Enhancing Antitumor Immune Responses by Optimized Combinations of Cell-penetrating Peptide-based Vaccines and Adjuvants

“…These variants were first studied by circular dichroism analysis which represents the technique of choice to estimate secondary structures of proteins and peptides in solution. 21 Alpha-helical structures, reported to control to a certain extent their cellular uptake, 18 are usually characterized by the presence of two negative bands at 208 and 222 nm along with one positive band at 192 nm. Circular dichroism analysis showed that almost all CPP constructs assessed exhibited an alpha-helical conformation but this secondary structure seemed to be favored in some of the shortest constructs Z15-, Z16-, and Z20-conjugates (Figure 1).…”

“…15,16 The secondary structure of CPPs is an important feature for their cellular uptake, 17 with helical structure being associated with strong CPP-membrane interactions. 18 Recently, a CPP derived from the viral protein ZEBRA was described to transduce protein cargoes across membranes by both direct translocation and lipid raft-mediated endocytosis. 19 We previously showed that these two mechanisms of entry promote both MHC class I and II restricted presentation of cargo antigens to CD8 and CD4 T cells, respectively.…”

Insights on the structural characteristics of Vim-TBS (58-81) peptide for future applications as a cell penetrating peptide

“…Among all CPPs, which include protein transduction domains (19), chimeric peptides and peptides of synthetic origin, the peptides derived from the HIV-1 Tat protein (1), from the homeodomain of the Antennapedia protein of Drosophila (Tat and Penetratin peptides, respectively), as well as the synthetic Pep-1 peptide (20), are the best characterized. These peptides have been successfully used for the intracellular delivery of different cargoes (21), including nanoparticles, full-length proteins, liposomes and nucleic acids, both in vitro and in vivo, thus resulting in successful transduction in animal tissues, including the brain.…”