title: Cellular uptake of Aib-containing amphipathic helix peptide.
abstract: Cell-penetrating peptides (CPPs) are useful tools for the delivery of hydrophilic bioactive molecules, such as peptides, proteins, and oligonucleotides, across the cell membrane. To realize the delivery of therapeutic macromolecules by CPPs, the CPPs are required to show resistance to protease and no cytotoxicity. In order to produce potent non-toxic and protease-resistant CPPs with high cellular uptake, we designed an amphipathic helix peptide using α-aminoisobutyric acid (Aib, U) and named it MAP(Aib). In the MAP(Aib) molecule, five Aib residues are aligned on the hydrophobic face of the helix and five lysine (K) residues are aligned on the hydrophilic face. MAP(Aib) showed potent resistance to trypsin and pronase compared with MAP, an amphipathic helix peptide formed by usual amino acids. Fluorescein-labeled MAP(Aib) efficiently traversed the A549 cell membrane, diffusing into the cytoplasm and slightly into the nucleus without exerting any cytotoxicity. In contrast, MAP was poorly taken up by the cell. These results indicate that the incorporation of Aib residues into CPPs markedly improves cellular uptake and MAP(Aib) may be a useful tool for the delivery of hydrophilic macromolecules.
authors.affiliation: Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan. wada@gly.oups.ac.jp
authors.forename: Shun-ichi
authors.initials: S
authors.lastname: Wada
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Tsuda
authors.forename: Terumi
authors.initials: T
authors.lastname: Okada
authors.forename: Hidehito
authors.initials: H
authors.lastname: Urata
mesh_terms: D000621:Aminoisobutyric Acids / Q000737:chemistry* / Q000378:metabolism; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism; D057846:Cell-Penetrating Peptides / Q000138:chemical synthesis* / Q000378:metabolism / Q000494:pharmacology / Q000633:toxicity; D015195:Drug Design; D055808:Drug Discovery; D004353:Drug Evaluation, Preclinical; D004847:Epithelial Cells; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D046911:Macromolecular Substances / Q000378:metabolism; D015394:Molecular Structure; D010455:Peptides / Q000138:chemical synthesis* / Q000378:metabolism / Q000494:pharmacology / Q000633:toxicity; D011402:Pronase / Q000378:metabolism; D017433:Protein Structure, Secondary; D014357:Trypsin / Q000378:metabolism
chemical_list: D000621:Aminoisobutyric Acids; D057846:Cell-Penetrating Peptides; C571354:MAP(Aib) peptide; D046911:Macromolecular Substances; D010455:Peptides; C100049:2-aminoisobutyric acid; D014357:Trypsin; D011402:Pronase