Vesicle size-dependent translocation of penetratin analogs across lipid membranes

Citations of this article
Mendeley users who have this article in their library.


The recent discoveries of serious artifacts associated with the use of cell fixation in studies of the cellular uptake of cell-penetrating peptides (CPPs) have prompted a reevaluation of the current understanding of peptide-mediated cellular delivery. Following a report on the differential cellular uptake of a number of penetratin analogs in unfixed cells, we here investigate their membrane translocation abilities in large and giant unilamellar vesicles (LUVs and GUVs, respectively). Surprisingly, in contrast to the behavior in living cells, all peptides readily entered the giant vesicles (>1 μm) as proved by confocal microscopy, while none of them could cross the membranes of LUVs (100 nm). For determination of the location of the peptides in the LUVs, a new concept was introduced, based on sensitive resonance energy transfer (RET) measurements of the enhanced fluorescence of acceptor fluorophores present solely in the inner leaflet. An easily adopted method to prepare such asymmetrically labeled liposomes is described. The membrane insertion depths of the tryptophan moieties of the peptides were determined by use of brominated lipids and found to be very similar for all of the peptides studied. We also demonstrate that infrared spectroscopy on the lipid carbonyl stretch vibration peak is a convenient technique to determine phospholipid concentration. © 2004 Elsevier B.V. All rights reserved.




Persson, D., Thorén, P. E. G., Esbjörner, E. K., Goksör, M., Lincoln, P., & Nordén, B. (2004). Vesicle size-dependent translocation of penetratin analogs across lipid membranes. Biochimica et Biophysica Acta - Biomembranes, 1665(1–2), 142–155.

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free