title: Biophysical characterization of V3-lipopeptide liposomes influencing HIV-1 infectivity.
abstract: 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.
authors.affiliation: 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
authors.forename: Apostolos K
authors.initials: AK
authors.lastname: Rizos
authors.forename: Stavroula
authors.initials: S
authors.lastname: Baritaki
authors.forename: Ioannis
authors.initials: I
authors.lastname: Tsikalas
authors.forename: David C
authors.initials: DC
authors.lastname: Doetschman
authors.forename: Demetrios A
authors.initials: DA
authors.lastname: Spandidos
authors.forename: Elias
authors.initials: E
authors.lastname: Krambovitis
mesh_terms: 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*
chemical_list: D016655:HIV Core Protein p24; D015699:HIV Envelope Protein gp120; D008074:Lipoproteins; D008081:Liposomes; D010455:Peptides