title: Cytosolic targeting of macromolecules using a pH-dependent fusogenic peptide in combination with cationic liposomes.
abstract: pH-Sensitive peptides and polymers have been employed as additives to enhance the cytosolic delivery of drugs and genes by facilitating their endosomal escape. However, little attention has been paid to the intracellular fate of these peptides and polymers. In this study, we explored the possibility of utilizing GALA, a pH-sensitive fusogenic peptide, as a cytosol-targeting vehicle. In combination with cationic liposomes, Lipofectamine 2000 (LF2000), the feasibility of this approach for the cytosolic targeting of proteins and nanoparticles was exemplified through the delivery of avidin (68 kDa) and streptavidin-coated quantum dots (15-20 nm) in serum-containing medium. The use of cationic liposomes is critical to enhance the cell-surface adhesion of the GALA conjugates and eventual endosomal uptake. Circular dichroism studies suggest that the GALA can be liberated from cationic liposomes at a reducing pH to form a helical structure and this may eventually lead to disruption of the endosomal membrane to achieve an efficient leakage of the GALA conjugates into the cytosol.
authors.affiliation: Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan.
authors.forename: Sachiko
authors.initials: S
authors.lastname: Kobayashi
authors.forename: Ikuhiko
authors.initials: I
authors.lastname: Nakase
authors.forename: Noriko
authors.initials: N
authors.lastname: Kawabata
authors.forename: Hao-Hsin
authors.initials: HH
authors.lastname: Yu
authors.forename: Sílvia
authors.initials: S
authors.lastname: Pujals
authors.forename: Miki
authors.initials: M
authors.lastname: Imanishi
authors.forename: Ernest
authors.initials: E
authors.lastname: Giralt
authors.forename: Shiroh
authors.initials: S
authors.lastname: Futaki
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001360:Avidin / Q000378:metabolism; D002460:Cell Line; D006224:Cricetinae; D003600:Cytosol / Q000378:metabolism*; D004058:Diffusion; D011992:Endosomes / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008055:Lipids / Q000008:administration & dosage / Q000737:chemistry*; D008081:Liposomes / Q000008:administration & dosage / Q000737:chemistry* / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D010455:Peptides / Q000008:administration & dosage / Q000737:chemistry* / Q000378:metabolism*; D021381:Protein Transport; D045663:Quantum Dots; D019809:Streptavidin / Q000378:metabolism
chemical_list: D008055:Lipids; C086724:Lipofectamine; D008081:Liposomes; D010455:Peptides; C066951:GALA peptide; D001360:Avidin; D019809:Streptavidin