title: Covalent attachment of cyclic TAT peptides to GFP results in protein delivery into live cells with immediate bioavailability.
abstract: The delivery of free molecules into the cytoplasm and nucleus by using arginine-rich cell-penetrating peptides (CPPs) has been limited to small cargoes, while large cargoes such as proteins are taken up and trapped in endocytic vesicles. Based on recent work, in which we showed that the transduction efficiency of arginine-rich CPPs can be greatly enhanced by cyclization, the aim was to use cyclic CPPs to transport full-length proteins, in this study green fluorescent protein (GFP), into the cytosol of living cells. Cyclic and linear CPP-GFP conjugates were obtained by using azido-functionalized CPPs and an alkyne-functionalized GFP. Our findings reveal that the cyclic-CPP-GFP conjugates are internalized into live cells with immediate bioavailability in the cytosol and the nucleus, whereas linear CPP analogues do not confer GFP transduction. This technology expands the application of cyclic CPPs to the efficient transport of functional full-length proteins into live cells.
authors.affiliation: Leibniz-Institut für Molekulare Pharmakologie (FMP), Robert-Rössle-Strasse 10, 13125 Berlin (Germany); Freie Universität Berlin, Institut für Chemie und Biochemie, Takustrasse 3, 14195 Berlin (Germany).
authors.forename: Nicole
authors.initials: N
authors.lastname: Nischan
authors.forename: Henry D
authors.initials: HD
authors.lastname: Herce
authors.forename: Francesco
authors.initials: F
authors.lastname: Natale
authors.forename: Nina
authors.initials: N
authors.lastname: Bohlke
authors.forename: Nediljko
authors.initials: N
authors.lastname: Budisa
authors.forename: M Cristina
authors.initials: MC
authors.lastname: Cardoso
authors.forename: Christian P R
authors.initials: CP
authors.lastname: Hackenberger
mesh_terms: D001682:Biological Availability; D057846:Cell-Penetrating Peptides / Q000008:administration & dosage* / Q000493:pharmacokinetics; D015696:Gene Products, tat / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics; D049452:Green Fluorescent Proteins / Q000737:chemistry*; D011506:Proteins / Q000008:administration & dosage* / Q000493:pharmacokinetics
chemical_list: D057846:Cell-Penetrating Peptides; D015696:Gene Products, tat; D011506:Proteins; D049452:Green Fluorescent Proteins
keywords: cell-penetrating peptides; click chemistry; cyclic peptides; live-cell microscopy; protein delivery