title: Importance of hydrophobic region in amphiphilic structures of alpha-helical peptides for their gene transfer-ability into cells.
abstract: It has been showned that cationic alpha-helical peptides can be useful as nucleic acid-carrier molecules for gene transfer into cells. In order to investigate the significancemake sure of importance of the hydrophobic region in amphiphilic peptides in relation to their transfection ability, we have employed five kinds of peptides with a systematically varied hydrophobic-hydrophilic balance in the amphiphilic structures, and have evaluated the relationship between the structure and the gene transfer ability of the peptides into COS-7 cells. The peptides with a large hydrophobic region took alpha-helical structures, formed large aggregates and showed high transfection efficiency. Their high efficiency can be explained on the basis of their ability to form stable aggregates which can be internalized by endocytosis and remain resistant to digestion in lysosomal vesicles. Furthermore, it was suggested that the hydrophobic region of peptides plays an important role in the disruption of the endosomal membrane, which ca prevent the degradation of DNA in lysosomal vesicles. When peptides do not have so strong membrane-disruptive activity, but form aggregates which can be incorporated by endocytosis, the transfection efficiency can be recovered by the addition of an endosome-disruptive peptide.
authors.affiliation: Department of Applied Chemistry, Faculty of Engineering, Nagasaki University, Nagasaki, 852-8521, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Ohmori
authors.forename: T
authors.initials: T
authors.lastname: Niidome
authors.forename: T
authors.initials: T
authors.lastname: Kiyota
authors.forename: S
authors.initials: S
authors.lastname: Lee
authors.forename: G
authors.initials: G
authors.lastname: Sugihara
authors.forename: A
authors.initials: A
authors.lastname: Wada
authors.forename: T
authors.initials: T
authors.lastname: Hirayama
authors.forename: H
authors.initials: H
authors.lastname: Aoyagi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D002942:Circular Dichroism; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry; D003850:Deoxyribonuclease I / Q000378:metabolism; D004705:Endocytosis / Q000502:physiology; D017930:Genes, Reporter / Q000235:genetics; D008247:Lysosomes / Q000378:metabolism; D008854:Microscopy, Electron; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry*; D017433:Protein Structure, Secondary; D013501:Surface-Active Agents / Q000737:chemistry / Q000494:pharmacology; D014162:Transfection / Q000235:genetics*
chemical_list: D004268:DNA-Binding Proteins; D010455:Peptides; D013501:Surface-Active Agents; D004247:DNA; D003850:Deoxyribonuclease I