title: Membrane interactions of two arginine-rich peptides with different cell internalization capacities.
abstract: Cell penetrating peptides (CPPs) can cross cell membranes in a receptor independent manner and transport cargo molecules inside cells. These peptides can internalize through two independent routes: energy dependent endocytosis and energy independent translocation across the membrane, but the exact mechanisms are still unknown. The interaction of the CPP with different membrane components is certainly a preliminary key point that triggers internalization, such as the interaction with lipids to lead to the translocation process. In this study, we used two arginine-rich peptides, RW9 (RRWWRRWRR-NH2), which is a potent CPP, and RL9 (RRLLRRLRR-NH2) that, although binding tightly and accumulating on membranes, does not enter into cells. Using a set of experimental and theoretical techniques, we studied the binding, insertion and orientation of the peptides into different model membranes as well as the subsequent membrane reorganization. Herein we show that although the two peptides had rather similar behavior regarding lipid membrane interaction, subtle differences were found concerning the depth of peptide insertion, effect on the lipid chain ordering and kinetics of peptide insertion in the membrane, which altogether might explain their different cell internalization capacities. Molecular dynamics simulation studies show that some peptide molecules flipped their orientation over the course of the simulation such that the hydrophobic residues penetrated deeper in the lipid core region while Arg-residues maintained H-bonds with the lipid headgroups, serving as a molecular hinge in a conformation that appeared to correspond to the equilibrium one.
authors.affiliation: UPMC-Paris 06, UMR 7203 CNRS, ENS, Laboratoire des BioMolecules, 4, place jussieu, Paris F-75005, France.
authors.forename: Astrid
authors.initials: A
authors.lastname: Walrant
authors.forename: Alexander
authors.initials: A
authors.lastname: Vogel
authors.forename: Isabelle
authors.initials: I
authors.lastname: Correia
authors.forename: Olivier
authors.initials: O
authors.lastname: Lequin
authors.forename: Bjoern E S
authors.initials: BE
authors.lastname: Olausson
authors.forename: Bernard
authors.initials: B
authors.lastname: Desbat
authors.forename: Sandrine
authors.initials: S
authors.lastname: Sagan
authors.forename: Isabel D
authors.initials: ID
authors.lastname: Alves
mesh_terms: D000595:Amino Acid Sequence; D001120:Arginine / Q000737:chemistry* / Q000378:metabolism; D002151:Calorimetry; D002462:Cell Membrane / Q000737:chemistry* / Q000378:metabolism; D057846:Cell-Penetrating Peptides / Q000737:chemistry* / Q000378:metabolism; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry / Q000378:metabolism; D004705:Endocytosis; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008563:Membrane Lipids / Q000737:chemistry* / Q000378:metabolism; D008823:Micelles; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D010713:Phosphatidylcholines / Q000737:chemistry / Q000378:metabolism; D010715:Phosphatidylglycerols / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D021381:Protein Transport; D012031:Refractometry / Q000379:methods; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D053835:Unilamellar Liposomes / Q000737:chemistry / Q000378:metabolism
chemical_list: D057846:Cell-Penetrating Peptides; D008051:Lipid Bilayers; D008563:Membrane Lipids; D008823:Micelles; D010713:Phosphatidylcholines; D010715:Phosphatidylglycerols; D053835:Unilamellar Liposomes; C060037:1-palmitoyl-2-oleoylglycero-3-phosphoglycerol; D001120:Arginine; C002773:dimyristoylphosphatidylglycerol; C028694:1-palmitoyl-2-oleoylphosphatidylcholine; D004134:Dimyristoylphosphatidylcholine