title: An Intrinsically Disordered Peptide Facilitates Non-Endosomal Cell Entry.
abstract: Many cell-penetrating peptides (CPPs) fold at cell surfaces, adopting α- or β-structure that enable their intracellular transport. However, the same structural folds that facilitate cellular entry can also elicit potent membrane-lytic activity, limiting their use in delivery applications. Further, a distinct CPP can enter cells through many mechanisms, often leading to endosomal entrapment. Herein, we describe an intrinsically disordered peptide (CLIP6) that exclusively employs non-endosomal mechanisms to cross cellular membranes, while being remarkably biocompatible and serum-stable. We show that a single anionic glutamate residue is responsible for maintaining the disordered bioactive state of the peptide, defines its mechanism of cellular entry, and is central to its biocompatibility. CLIP6 can deliver membrane-impermeable cargo directly to the cytoplasm of cells, suggesting its broad utility for delivery of drug candidates limited by poor cell permeability and endosomal degradation.
authors.affiliation: Chemical Biology Laboratory, National Cancer Institute, National Institutes of Health Fort Detrick, 376 Boyle Street, Frederick, MD, 21702-1201, USA.
authors.forename: Scott H
authors.initials: SH
authors.lastname: Medina
authors.affiliation: Chemical Biology Laboratory, National Cancer Institute, National Institutes of Health Fort Detrick, 376 Boyle Street, Frederick, MD, 21702-1201, USA.
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Miller
authors.affiliation: Chemical Biology Laboratory, National Cancer Institute, National Institutes of Health Fort Detrick, 376 Boyle Street, Frederick, MD, 21702-1201, USA.
authors.forename: Allison I
authors.initials: AI
authors.lastname: Keim
authors.affiliation: Chemical Biology Laboratory, National Cancer Institute, National Institutes of Health Fort Detrick, 376 Boyle Street, Frederick, MD, 21702-1201, USA.
authors.forename: Alexander P
authors.initials: AP
authors.lastname: Gorka
authors.affiliation: Chemical Biology Laboratory, National Cancer Institute, National Institutes of Health Fort Detrick, 376 Boyle Street, Frederick, MD, 21702-1201, USA.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Schnermann
authors.affiliation: Chemical Biology Laboratory, National Cancer Institute, National Institutes of Health Fort Detrick, 376 Boyle Street, Frederick, MD, 21702-1201, USA. Joel.Schneider@nih.gov.
authors.forename: Joel P
authors.initials: JP
authors.lastname: Schneider
mesh_terms: D000595:Amino Acid Sequence; D004705:Endocytosis / Q000502:physiology*; D011992:Endosomes / Q000378:metabolism*; D006801:Humans; D064267:Intrinsically Disordered Proteins / Q000737:chemistry / Q000502:physiology*; D010455:Peptides / Q000737:chemistry / Q000502:physiology*
chemical_list: D064267:Intrinsically Disordered Proteins; D010455:Peptides
keywords: cell-penetrating peptides; drug delivery; gene expression; live-cell microscopy; translocation
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