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Cell-penetrating HIV1 TAT peptides float on model lipid bilayers.

Ciobanasu, Corina ; Harms, Enno ; Tünnemann, Gisela ; Cardoso, M. Cristina ; Kubitscheck, Ulrich (2009)
Cell-penetrating HIV1 TAT peptides float on model lipid bilayers.
In: Biochemistry, 48 (22)
Artikel, Bibliographie

Kurzbeschreibung (Abstract)

Cell-penetrating peptides like the cationic HIV1 TAT peptide are able to translocate across cell membranes and to carry molecular cargoes into the cellular interior. For most of these peptides, the biophysical mechanism of the membrane translocation is still quite unknown. We analyzed HIV1 TAT peptide binding and mobility within biological model membranes. To this end, we generated neutral and anionic giant unilamellar vesicles (GUVs) containing DPPC, DOPC, and cholesterol and containing DPPC, DOPC, cholesterol, and DPPS (DOPS), respectively. First, we characterized the mobility of fluorescently labeled lipids (TR-DHPE) within liquid-ordered and liquid-disordered lipid phases by single-molecule tracking, yielding a D(LO) of 0.6 +/- 0.05 microm(2)/s and a D(LD) of 2.5 +/- 0.05 microm(2)/s, respectively, as a reference. Fluorescently labeled TAT peptides accumulated on neutral GUVs but bound very efficiently to anionic GUVs. Single-molecule tracking revealed that HIV1 TAT peptides move on neutral and anionic GUV surfaces with a D(N,TAT) of 5.3 +/- 0.2 microm(2)/s and a D(A,TAT) of 3.3 +/- 0.2 mum(2)/s, respectively. TAT peptide diffusion was faster than fluorescent lipid diffusion, and also independent of the phase state of the membrane. We concluded that TAT peptides are not incorporated into but rather floating on lipid bilayers, but they immerged deeper into the headgroup domain of anionic lipids. The diffusion constants were not dependent on the TAT concentration ranging from 150 pM to 2 microM, indicating that the peptides were not aggregated on the membrane and not forming any "carpet".

Typ des Eintrags: Artikel
Erschienen: 2009
Autor(en): Ciobanasu, Corina ; Harms, Enno ; Tünnemann, Gisela ; Cardoso, M. Cristina ; Kubitscheck, Ulrich
Art des Eintrags: Bibliographie
Titel: Cell-penetrating HIV1 TAT peptides float on model lipid bilayers.
Sprache: Englisch
Publikationsjahr: 2009
Titel der Zeitschrift, Zeitung oder Schriftenreihe: Biochemistry
Jahrgang/Volume einer Zeitschrift: 48
(Heft-)Nummer: 22
URL / URN: http://www.cardoso-lab.org/publications/Ciobanasu_2009.pdf
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Kurzbeschreibung (Abstract):

Cell-penetrating peptides like the cationic HIV1 TAT peptide are able to translocate across cell membranes and to carry molecular cargoes into the cellular interior. For most of these peptides, the biophysical mechanism of the membrane translocation is still quite unknown. We analyzed HIV1 TAT peptide binding and mobility within biological model membranes. To this end, we generated neutral and anionic giant unilamellar vesicles (GUVs) containing DPPC, DOPC, and cholesterol and containing DPPC, DOPC, cholesterol, and DPPS (DOPS), respectively. First, we characterized the mobility of fluorescently labeled lipids (TR-DHPE) within liquid-ordered and liquid-disordered lipid phases by single-molecule tracking, yielding a D(LO) of 0.6 +/- 0.05 microm(2)/s and a D(LD) of 2.5 +/- 0.05 microm(2)/s, respectively, as a reference. Fluorescently labeled TAT peptides accumulated on neutral GUVs but bound very efficiently to anionic GUVs. Single-molecule tracking revealed that HIV1 TAT peptides move on neutral and anionic GUV surfaces with a D(N,TAT) of 5.3 +/- 0.2 microm(2)/s and a D(A,TAT) of 3.3 +/- 0.2 mum(2)/s, respectively. TAT peptide diffusion was faster than fluorescent lipid diffusion, and also independent of the phase state of the membrane. We concluded that TAT peptides are not incorporated into but rather floating on lipid bilayers, but they immerged deeper into the headgroup domain of anionic lipids. The diffusion constants were not dependent on the TAT concentration ranging from 150 pM to 2 microM, indicating that the peptides were not aggregated on the membrane and not forming any "carpet".

Fachbereich(e)/-gebiet(e): 10 Fachbereich Biologie > Cell Biology and Epigenetics
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10 Fachbereich Biologie
Hinterlegungsdatum: 06 Mär 2010 16:07
Letzte Änderung: 05 Mär 2013 09:32
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