title: Human-protein-derived peptides for intracellular delivery of biomolecules.
abstract: Access of therapeutic biomolecules to cytoplasmic and nuclear targets is hampered by the inability of these molecules to cross biological membranes. Approaches to overcome this hurdle involve CPPs (cell-penetrating peptides) or protein transduction domains. Most of these require rather high concentrations to elicit cell-penetrating functionality, are non-human, pathogen-derived or synthetic entities, and may therefore not be tolerated or even immunogenic. We identified novel human-protein-derived CPPs by a combination of in silico and experimental analyses: polycationic CPP candidates were identified in an in silico library of all 30-mer peptides of the human proteome. Of these peptides, 60 derived from extracellular proteins were evaluated experimentally. Cell viability and siRNA (small interfering RNA) transfection assays revealed that 20 out of the 60 peptides were functional. Three of these showed CPP functionality without interfering with cell viability. A peptide derived from human NRTN (neurturin), which contains an α-helix, performed the best in our screen and was uniformly taken up by cultured cells. Examples for payloads that can be delivered to the cytosol by the NRTN peptide include complexed siRNAs and both N- and C-terminally fused pro-apoptotic peptides.
authors.affiliation: Roche Pharma Research and Early Development, Large Molecule Research, Penzberg, Germany. Alexander.Haas@Roche.com
authors.forename: Alexander K
authors.initials: AK
authors.lastname: Haas
authors.forename: Daniela
authors.initials: D
authors.lastname: Maisel
authors.forename: Juliane
authors.initials: J
authors.lastname: Adelmann
authors.forename: Christoffer
authors.initials: C
authors.lastname: von Schwerin
authors.forename: Ines
authors.initials: I
authors.lastname: Kahnt
authors.forename: Ulrich
authors.initials: U
authors.lastname: Brinkmann
mesh_terms: D000595:Amino Acid Sequence; D002470:Cell Survival; D057846:Cell-Penetrating Peptides / Q000008:administration & dosage / Q000737:chemistry*; D002478:Cells, Cultured; D003600:Cytosol / Q000378:metabolism; D016503:Drug Delivery Systems / Q000379:methods*; D006801:Humans; D034741:RNA, Small Interfering; D014162:Transfection
chemical_list: D057846:Cell-Penetrating Peptides; D034741:RNA, Small Interfering