title: A novel chimeric cell-penetrating peptide with membrane-disruptive properties for efficient endosomal escape.
abstract: Efficient endocytosis into a wide range of target cells and low toxicity make the arginine-rich Tat peptide (Tat(11): YGRKKRRQRRR, residues 47-57 of HIV-1 Tat protein) an excellent transporter for delivery purposes. Unfortunately, molecules taken up by endocytosis undergo endosomal entrapment and possible metabolic degradation. Escape from the endosome is therefore actively researched. In this context, antimicrobial peptides (AMPs) provide viable templates for the design of new membrane-disruptive motifs. In particular the Cecropin-A and Melittin hybrids (CMs) are among the smallest and most effective peptides with membrane-perturbing abilities. Here we present a novel chimeric peptide in which the Tat(11) motif is fused to the CM(18) hybrid (KWKLFKKIGAVLKVLTTG, residues 1-7 of Cecropin-A and 2-12 of Melittin). When administered to cells, CM(18)-Tat(11) combines the two desired functionalities: efficient uptake and destabilization of endocytotic-vesicle membranes. We show that this chimeric peptide effectively increases cargo-molecule cytoplasm availability and allows the subsequent intracellular localization of diverse membrane-impermeable molecules (i.e. Tat(11)-EGFP fusion protein, calcein, dextrans, and plasmidic DNA) with no detectable cytotoxicity. The present results open the way to the rational engineering of "modular" cell-penetrating peptides (CPPs) that combine (i) efficient translocation from the extracellular milieu into vesicles and (ii) efficient release of molecules from vesicles into the cytoplasm.
authors.affiliation: NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, Piazza San Silvestro 12-56127 Pisa, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Salomone
authors.forename: Francesco
authors.initials: F
authors.lastname: Cardarelli
authors.forename: Mariagrazia
authors.initials: M
authors.lastname: Di Luca
authors.forename: Claudia
authors.initials: C
authors.lastname: Boccardi
authors.forename: Riccardo
authors.initials: R
authors.lastname: Nifosì
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Bardi
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Di Bari
authors.forename: Michela
authors.initials: M
authors.lastname: Serresi
authors.forename: Fabio
authors.initials: F
authors.lastname: Beltram
mesh_terms: D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000008:administration & dosage*; D016466:CHO Cells; D002462:Cell Membrane / Q000187:drug effects* / Q000378:metabolism; D057846:Cell-Penetrating Peptides / Q000008:administration & dosage*; D006224:Cricetinae; D003412:Cricetulus; D004247:DNA / Q000378:metabolism; D003911:Dextrans / Q000378:metabolism; D004705:Endocytosis / Q000187:drug effects; D011992:Endosomes / Q000187:drug effects; D005452:Fluoresceins / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D061307:Human Umbilical Vein Endothelial Cells / Q000378:metabolism; D006801:Humans; D013211:Staphylococcus aureus / Q000187:drug effects; D014162:Transfection
chemical_list: D023181:Antimicrobial Cationic Peptides; D057846:Cell-Penetrating Peptides; D003911:Dextrans; D005452:Fluoresceins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D004247:DNA; C007740:fluorexon