Effect of Preorganized Charge‐Display on the Cell‐Penetrating Properties of Cationic Peptides

Abstract

The effect of preorganized versus undefined charge display on the cellular uptake of cationic cell-penetrating peptides (CPPs) was investigated by comparing conformationally well-defined guanidinylated oligoprolines with flexible oligoarginines. Flow cytometry and confocal microscopy studies with different cancer cell lines (HeLa, MCF-7, and HT-29) showed that preorganization of cationic charges in lateral distances of ≈9 Å enhanced the cellular uptake of CPPs. Binding affinity measurements revealed tighter binding of analogues of cell-surface glycans to the guanidinylated octaproline with localized charges compared to flexible octaarginine, a finding that was further correlated to the cellular uptake by studies with CHO cells deficient in glycans on the outer plasma membrane.

Ribbon‐like Foldamers for Cellular Uptake and Drug Delivery

“…Such a distance was reported by Wennemers et al. as being optimal for interaction with cell‐membrane proteoglycans, and subsequently, suitable for efficient cell internalization . Along with these studies, our results strongly suggested that the defined spatial orientation of the cationic and aromatic residues in this class of compounds was important for optimizing interactions with the cell membrane and subsequent cellular uptake.…”

“…Although the influence of CPP secondary structure on the mechanism of internalization and potency remains ambiguous, several studies have shown that the structural preorganization of arginine‐rich CPPs through cyclization and the use of α‐helical mimics, including polyproline helix scaffolds and helical polycationic polymers, is a factor that contributes to the cellular uptake efficiency. In a recent study, the group of Wennemers proposed that enhancement of the cytosolic uptake of the guanidine‐functionalized oligoproline family could be correlated with the arrangement of cationic charges at a distance of about 10 Å, similar to the space between the negative charges of cell‐surface glycans . Tryptophan (Trp) is another pivotal amino acid for intracellular uptake due to its strong interaction with cell membranes .…”

Cytosolic Delivery of Proteins by Bioreversible Esterification

“…, penetratin, TP10, and p VEC) consist of cationic and hydrophobic residues, which impart an amphipathic character. 7e,7f,14 Their hydrophobic residues are crucial for mediating membrane translocation.…”

Functionalized Proline‐Rich Peptides Bind the Bacterial Second Messenger c‐di‐GMP

“…[25] Peptide 1,t he tightest and most selective binder of c-di-GMP amongst the examined tetrapeptides,l imits biofilm formation to 50 %a tac oncentration of around 80 mm (IC 50 ). [26] We therefore tested tripeptide 1f,which lacks this residue,and tetrapeptide 1e,w hich bears a d-Arg at the Cterminus,a nd we observed four-a nd two-fold lower activity,r espectively.A dditional control experiments with the proteolytically stable tetrapeptide Ac-[dArg] 4 -NH 2 (6;I C 50 > 5mm)c orroborated these findings and further showed that the combination of cationic charges and an aromatic residue is critical to observe inhibition of biofilm growth. Thus,the combination of cationic charges and an aromatic residue is critical for the inhibition of biofilm growth.…”