Uptake of analogs of penetratin, Tat(48-60) and oligoarginine in live cells
Journal article, 2003

Cell-penetrating peptides are regarded as promising vectors for intracellular delivery of large, hydrophilic molecules, but their mechanism of uptake is poorly understood. Since it has now been demonstrated that the use of cell fixation leads to artifacts in microscopy studies on the cellular uptake of such peptides, much of what has been considered as established facts must be reinvestigated using live (unfixed) cells. In this work, the uptake of analogs of penetratin, Tat(48-60), and heptaarginine in two different cell lines was studied by confocal laser scanning microscopy. For penetratin, an apparently endocytotic uptake was observed, in disagreement with previous studies on fixed cells found in the literature. Substitution of the two tryptophan residues, earlier reported to be essential for cellular uptake, did not alter the uptake characteristics. A heptaarginine peptide, with a tryptophan residue added in the C-terminus, was found to be internalized by cells via an energy-independent, non-endocytotic pathway. Finally, a crucial role for arginine residues in penetratin and Tat(48-60) was demonstrated. © 2003 Elsevier Science (USA). All rights reserved.


Per Thoren

Chalmers, Department of Chemistry and Bioscience

Daniel Persson

Chalmers, Department of Chemistry and Bioscience

Petter Isakson

Chalmers, Department of Chemistry and Bioscience

Mattias Goksör

University of Gothenburg

Agneta Önfelt

Stockholm University

Bengt Nordén

Chalmers, Department of Chemistry and Bioscience

Biochemical and Biophysical Research Communications

0006-291X (ISSN) 1090-2104 (eISSN)

Vol. 307 1 100-107

Subject Categories

Biochemistry and Molecular Biology

Atom and Molecular Physics and Optics



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