Biophysical characterization of V3-lipopeptide liposomes influencing HIV-1 infectivity.
The V3-loop of the HIV-1 gp120 alters host cell immune function and modulates infectivity. We investigated biophysical parameters of liposome constructs with embedded lipopeptides from the principle neutralizing domain of the V3-loop and their influence on viral infectivity. Dynamic light scattering measurements showed liposome supramolecular structures with hydrodynamic radius of the order of 900 and 1300nm for plain and V3-lipopeptide liposomes. Electron paramagnetic resonance measurements showed almost identical local microenvironment. The difference in liposome hydrodynamic radius was attributed to the fluctuating ionic environment of the V3-lipopeptide liposomes. In vitro HIV-1 infectivity assays showed that plain liposomes reduced virus production in all cell cultures, probably due to the hydrophobic nature of the aggregates. Liposomes carrying V3-lipopeptides with different cationic potentials restored and even enhanced infectivity (p<0.05). These results highlight the need for elucidation of the involvement of lipid bilayers as dynamic components in supramolecular structures and in HIV-1 fusion mechanisms.
Rizos
Apostolos K
AK
Department of Chemistry and Foundation for Research and Technology-Hellas (FORTH-IESL), University of Crete, P.O. Box 2208, Heraklion 71003, Greece. Rizos@iesl.forth.gr
Baritaki
Stavroula
S
Tsikalas
Ioannis
I
Doetschman
David C
DC
Spandidos
Demetrios A
DA
Krambovitis
Elias
E
D055592:Biophysical Phenomena; D001703:Biophysics; D004578:Electron Spin Resonance Spectroscopy; D016655:HIV Core Protein p24 / Q000096:biosynthesis; D015699:HIV Envelope Protein gp120 / Q000737:chemistry* / Q000378:metabolism*; D015497:HIV-1 / Q000502:physiology*; D006801:Humans; D008074:Lipoproteins / Q000737:chemistry*; D008081:Liposomes; D010455:Peptides / Q000737:chemistry*
D016655:HIV Core Protein p24; D015699:HIV Envelope Protein gp120; D008074:Lipoproteins; D008081:Liposomes; D010455:Peptides