Energy-independent translocation of cell-penetrating peptides occurs without formation of pores. A biophysical study with pep-1.

S.T. HENRIQUES; A. QUINTAS; LUIS A. BAGATOLLI; F. HOMBLÉ; M.A. CASTANHO

MOLECULAR MEMBRANE BIOLOGY

TAYLOR & FRANCIS LTD

Lugar: Londres; Año: 2007 vol. 24 p. 282 - 282

0968-7688

div class="">Pep-1 is a cell-penetrating peptide (CPP) with the ability to translocate across biological membranes and introduce active proteins inside cells. The uptake mechanism used by this CPP is, as yet, unknown in detail. Previous results show that such a mechanism is endocytosis-independent and suggests that physical-chemical interactions between the peptide and lipid bilayers govern the translocation mechanism. Formation of a transmembrane pore has been proposed but this issue has always remained controversial. In this work the secondary structure of pep-1 in the absence/presence of lipidic bilayers was determined by CD and ATR-FTIR spectroscopies and the occurrence of pore formation was evaluated through electrophysiological measurements with planar lipid membranes and by confocal microscopy using giant unilamellar vesicles. Despite pep-1 hydrophobic domain tendency for amphipathic alpha-helix conformation in the presence of lipidic bilayers, there was no evidence for memb