title: Accumulation of cell-penetrating peptides in large unilamellar vesicles: A straightforward screening assay for investigating the internalization mechanism.
abstract: The internalization of cell-penetrating peptides (CPPs) into liposomes (large unilamellar vesicles, LUVs) was studied with a rapid and robust procedure based on the quenching of a small fluorescent probe, 7-nitrobenz-2-oxa-1,3-diazole (NBD). Quenching can be achieved by reduction with dithionite or by pH jump. LUVs with different compositions of phospholipids (PLs) were used to screen the efficacy of different CPPs. In order to "validate" the composition of the membrane models, a control cationic peptide, which does not enter eukaryotic cells, was included in the study. It was found that pure DOPG or DOPG within ternary mixtures with cholesterol are the most appropriate models for studying CPP translocation. An anionic lipid, such as DOPG, is required for the adsorption of the basic peptides on the surface of LUVs. In addition, it acts as transfer agent through the lipid bilayer. A fluid phase and/or the presence of phase defects also appear mandatory for the internalization to occur. The neutralization of charges within an inverted micelle demonstrated in the case of DOPG and also proposed for a ternary mixture of PLs might not be the only mechanism for the CPP translocation. Finally, it is shown that oleic acid facilitates the entry inside LUVs in gel phase of a series of cationic peptides including CPPs and also the negative control peptide PKCi.
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, LBM, 4, Place Jussieu, 75005, Paris, France.|Département de Chimie, Ecole Normale Supérieure-PSL Research University, 24, Rue Lhomond, 75005, Paris, France.|CNRS, UMR 7203, LBM, 75005, Paris, France.
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Swiecicki
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, LBM, 4, Place Jussieu, 75005, Paris, France.|Département de Chimie, Ecole Normale Supérieure-PSL Research University, 24, Rue Lhomond, 75005, Paris, France.|CNRS, UMR 7203, LBM, 75005, Paris, France.
authors.forename: Margherita
authors.initials: M
authors.lastname: Di Pisa
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, LBM, 4, Place Jussieu, 75005, Paris, France.|Département de Chimie, Ecole Normale Supérieure-PSL Research University, 24, Rue Lhomond, 75005, Paris, France.|CNRS, UMR 7203, LBM, 75005, Paris, France.
authors.forename: Fabienne
authors.initials: F
authors.lastname: Burlina
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, LBM, 4, Place Jussieu, 75005, Paris, France.|Département de Chimie, Ecole Normale Supérieure-PSL Research University, 24, Rue Lhomond, 75005, Paris, France.|CNRS, UMR 7203, LBM, 75005, Paris, France.
authors.forename: Pascaline
authors.initials: P
authors.lastname: Lécorché
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, LBM, 4, Place Jussieu, 75005, Paris, France.|Département de Chimie, Ecole Normale Supérieure-PSL Research University, 24, Rue Lhomond, 75005, Paris, France.|CNRS, UMR 7203, LBM, 75005, Paris, France.
authors.forename: Christelle
authors.initials: C
authors.lastname: Mansuy
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, LBM, 4, Place Jussieu, 75005, Paris, France.|Département de Chimie, Ecole Normale Supérieure-PSL Research University, 24, Rue Lhomond, 75005, Paris, France.|CNRS, UMR 7203, LBM, 75005, Paris, France.
authors.forename: Gérard
authors.initials: G
authors.lastname: Chassaing
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, LBM, 4, Place Jussieu, 75005, Paris, France.|Département de Chimie, Ecole Normale Supérieure-PSL Research University, 24, Rue Lhomond, 75005, Paris, France.|CNRS, UMR 7203, LBM, 75005, Paris, France.
authors.forename: Solange
authors.initials: S
authors.lastname: Lavielle
mesh_terms: D023181:Antimicrobial Cationic Peptides / Q000737:chemistry; D001681:Biological Assay / Q000379:methods*; D057846:Cell-Penetrating Peptides / Q000737:chemistry / Q000378:metabolism*; D005456:Fluorescent Dyes / Q000737:chemistry; D013997:Time Factors; D053835:Unilamellar Liposomes / Q000737:chemistry / Q000378:metabolism*
chemical_list: D023181:Antimicrobial Cationic Peptides; D057846:Cell-Penetrating Peptides; D005456:Fluorescent Dyes; D053835:Unilamellar Liposomes
keywords: cell-penetrating peptides; fatty acid; lipid vesicles; ordered and disordered phases; quenching of fluorescence; translocation