Vesicle size-dependent translocation of penetratin analogs across lipid membranes
Artikel i vetenskaplig tidskrift, 2004

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.


Daniel Persson

Chalmers, Institutionen för kemi och biovetenskap

Per Thoren

Chalmers, Institutionen för kemi och biovetenskap

Elin Esbjörner Winters

Chalmers, Institutionen för kemi och biovetenskap, Fysikalisk kemi

Mattias Goksör

Göteborgs universitet

Per Lincoln

Chalmers, Institutionen för kemi och biovetenskap, Fysikalisk kemi

Bengt Nordén

Chalmers, Institutionen för kemi och biovetenskap

Biochimica et Biophysica Acta - Biomembranes

0005-2736 (ISSN)

Vol. 1665 1-2 142-155


Medicinsk bioteknologi (med inriktning mot cellbiologi (inklusive stamcellsbiologi), molekylärbiologi, mikrobiologi, biokemi eller biofarmaci)



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