PT  - JOURNAL ARTICLE
AU  - Astrid Walrant
AU  - Antonio Bauzá
AU  - Claudia Girardet
AU  - Isabel D. Alves
AU  - Sophie Lecomte
AU  - Françoise Illien
AU  - Sébastien Cardon
AU  - Natpasit Chaianantakul
AU  - Manjula Pallerla
AU  - Fabienne Burlina
AU  - Antonio Frontera
AU  - Sandrine Sagan
TI  - Ionpair-π interactions favor cell penetration of arginine/tryptophan-rich cell-penetrating peptides
AID  - 10.1101/717207
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 717207
4099  - http://biorxiv.org/content/early/2019/07/27/717207.short
4100  - http://biorxiv.org/content/early/2019/07/27/717207.full
AB  - Cell-penetrating peptides (CPPs) internalization can occur both by endocytosis and direct translocation through the cell membrane. These different entry routes suggest that molecular partners at the plasma membrane, phospholipids or glycosaminoglycans (GAGs), bind CPPs with different affinity or selectivity. The analysis of sequence-dependent interactions of CPPs with lipids and GAGs should lead to a better understanding of the molecular mechanisms underlying their internalization. CPPs are short sequences generally containing a high number of basic arginines and lysines and sometimes aromatic residues, in particular tryptophans. Tryptophans are crucial residues in membrane-active peptides, because they are important for membrane interaction. Membrane-active peptides often present facial amphiphilicity, which also promote the interaction with lipid bilayers. To study the role of Trp and facial amphiphilicity in cell interaction and penetration of CPPs, a nonapeptide series containing only Arg, Trp or D-Trp residues at different positions was designed. Our quantitative study indicates that to maintain/increase the uptake efficiency, Arg can be advantageously replaced by Trp in the nonapeptides. The presence of Trp in oligoarginines increases the uptake in cells expressing GAGs at their surface, when it only compensates for the loss of Arg and maintains similar peptide uptake in GAG-deficient cells. In addition, we show that facial amphiphilicity is not required for efficient uptake of these nonapeptides. Thermodynamic analyses point towards a key role of Trp that highly contributes to the binding enthalpy of complexes formation. Density functional theory (DFT) analysis highlights that salt bridge-π interactions play a crucial role for the GAG-dependent entry mechanisms.ART-FTIRAttenuated Total Reflection Fourier Transformed Infra RedCHOChinese Hamster OvaryCPPCell-Penetrating PeptideDFTDensity functional theoryDMPG1,2-dimyristoyl sn-glycero-3-phospho-(1’-rac- glycerol)DSCDifferential Scanning CalorimetryGAGGlycosaminoglycanITCIsothermal Titration CalorimetryPOPG1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-(1’-rac-glycerol).