title: On the mechanism of non-endosomial peptide-mediated cellular delivery of nucleic acids.
abstract: Recently, we described a new strategy for the delivery of nucleic acids into mammalian cells, based on an amphipathic peptide of 27 residues called MPG, which was designed on the basis of a hydrophobic domain derived from a fusion sequence associated with a nuclear localization sequence and separated by a linker. This peptide carrier constitutes a powerful tool for the delivery of nucleic acids in cultured cells, without requiring any covalent coupling. We have examined the conformational states of MPG in its free form and complexed with a cargo, as well as its ability to interact with phospholipids, and have investigated the structural consequences of these interactions. In spite of its similarity to the similarly designed cell-penetrating peptide Pep-1, MPG behaves significantly differently from the conformational point of view. Circular dichroism (CD) analysis reveals a transition from a nonstructured to a beta-sheet conformation upon interaction with phospholipids. We propose that the membrane crossing process involves formation of a transient transmembrane pore-like structure. Partial conformational change of MPG is associated with formation of a complex with its cargo, and an increase in sheet content occurs upon association with the cell membrane.
authors.affiliation: CRBM-CNRS, FRE 2593, 1919, route de Mende, 34293 Montpellier Cedex, France.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Deshayes
authors.forename: Sabine
authors.initials: S
authors.lastname: Gerbal-Chaloin
authors.forename: May C
authors.initials: MC
authors.lastname: Morris
authors.forename: Gudrun
authors.initials: G
authors.lastname: Aldrian-Herrada
authors.forename: Pierre
authors.initials: P
authors.lastname: Charnet
authors.forename: Gilles
authors.initials: G
authors.lastname: Divita
authors.forename: Frédéric
authors.initials: F
authors.lastname: Heitz
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002463:Cell Membrane Permeability; D002942:Circular Dichroism; D024202:Electrophoretic Mobility Shift Assay; D011992:Endosomes / Q000378:metabolism*; D005260:Female; D013058:Mass Spectrometry; D008954:Models, Biological; D009696:Nucleic Acids / Q000235:genetics / Q000378:metabolism*; D009841:Oligonucleotides / Q000737:chemistry / Q000378:metabolism; D009865:Oocytes / Q000502:physiology; D018408:Patch-Clamp Techniques; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D010713:Phosphatidylcholines / Q000737:chemistry; D010715:Phosphatidylglycerols / Q000737:chemistry; D011487:Protein Conformation; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared; D014982:Xenopus laevis
chemical_list: D009696:Nucleic Acids; D009841:Oligonucleotides; D010455:Peptides; D010713:Phosphatidylcholines; D010715:Phosphatidylglycerols; D019253:Proto-Oncogene Proteins c-bcl-2; C051388:1,2-dioleoyl-sn-glycero-3-phosphoglycerol; C017251:1,2-oleoylphosphatidylcholine