title: Cellular internalization of a cargo complex with a novel peptide derived from the third helix of the islet-1 homeodomain. Comparison with the penetratin peptide.
abstract: Cellular translocation into a human Bowes melanoma cell line was investigated and compared for penetratin and pIsl, two peptides that correspond to the third helices of the related homeodomains, from the Antennapedia transcription factor of Drosophila and the rat insulin-1 gene enhancer protein, respectively. Both biotinylated peptides internalized into the cells with similar efficacy, yielding an analogous intracellular distribution. When a large cargo protein, 63 kDa avidin, was coupled to either peptide, efficient cellular uptake for both the peptide-protein complexes was observed. The interactions between each peptide and SDS micelles were studied by fluorescence spectroscopy and acrylamide quenching of the intrinsic tryptophan (Trp) fluorescence. Both peptides interacted strongly and almost identically with the membrane mimicking environment. Compared to penetratin, the new transport peptide pIsl has only one Trp residue, which simplifies the interpretation of the fluorescence spectra and in addition has a native Cys residue, which may be used for alternative coupling reactions of cargoes of different character.
authors.affiliation: Department of Neurochemistry and Neurotoxicology, Arrhenius Laboratories, University of Stockholm, SE-106 91, Stockholm, Sweden.
authors.forename: K
authors.initials: K
authors.lastname: Kilk
authors.forename: M
authors.initials: M
authors.lastname: Magzoub
authors.forename: M
authors.initials: M
authors.lastname: Pooga
authors.forename: L E
authors.initials: LE
authors.lastname: Eriksson
authors.forename: U
authors.initials: U
authors.lastname: Langel
authors.forename: A
authors.initials: A
authors.lastname: Gräslund
mesh_terms: D000818:Animals; D001360:Avidin / Q000494:pharmacology; D001692:Biological Transport; D019921:Biotinylation; D002352:Carrier Proteins / Q000494:pharmacology; D057846:Cell-Penetrating Peptides; D004330:Drosophila; D016503:Drug Delivery Systems; D018398:Homeodomain Proteins / Q000737:chemistry*; D006801:Humans; D060850:LIM-Homeodomain Proteins; D008823:Micelles; D009419:Nerve Tissue Proteins; D010446:Peptide Fragments / Q000494:pharmacology*; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000494:pharmacology*; D051381:Rats; D012967:Sodium Dodecyl Sulfate; D013050:Spectrometry, Fluorescence; D014157:Transcription Factors; D014407:Tumor Cells, Cultured / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D057846:Cell-Penetrating Peptides; D018398:Homeodomain Proteins; D060850:LIM-Homeodomain Proteins; D008823:Micelles; D009419:Nerve Tissue Proteins; D010446:Peptide Fragments; D011506:Proteins; D014157:Transcription Factors; C063843:insulin gene enhancer binding protein Isl-1; D001360:Avidin; D012967:Sodium Dodecyl Sulfate; C414409:penetratin