title: [Fusion of negatively-charged liposomes under the effect of peptides from the N-terminal fragment of the HIV-1 transmembrane protein].
abstract: The effect of a series of synthetic peptides mimicking the N-terminus of HIV transmembrane glycoprotein (gp41) on fusion of negatively charged liposomes consisting of phosphatidylcholine, phosphatidylethanolamine and cardiolipin at a 2:3:5 molar ratio, respectively, has been studied. Peptides P514 and P385 (residue 517-538), lysine and arginine at the C-terminus, respectively, with the amino acid sequence completely corresponding to the N-terminus of gp41 displayed the highest fusogenic activity. The extent of fusion was significantly increased at mild acidic pH (6.0). Acidification particularly influenced the fusogenic activity of P514. Modification of the N- and C-termini of fusion-active peptides by proteins and synthetic polymers blocked the fusion activity. The fusogenic properties of peptides depended on the chain length: P411 consisting of nine hydrophobic amino acid residues had no fusogenic activity, while P415, an 11-member peptide, effectively fused liposomes. The fluorescent probe ANS was used to monitor the hydrophobicity of these peptides. The hydrophobicity of P514 increased appreciably with a change in pH from 6.0 to 7.5. Peptides P514 and P385 induced the leakage of the aqueous contents from liposomes at neutral pH and caused a small, but detectable leakage at acidic pH. Structural and molecular factors influencing the peptide-induced liposome fusion are discussed.
authors.forename: Ia T
authors.initials: IaT
authors.lastname: Terletskaia
authors.forename: I O
authors.initials: IO
authors.lastname: Trikash
authors.forename: E S
authors.initials: ES
authors.lastname: Serdiuk
authors.forename: S M
authors.initials: SM
authors.lastname: Andreev
mesh_terms: D000595:Amino Acid Sequence; D015700:HIV Envelope Protein gp41 / Q000737:chemistry*; D015497:HIV-1 / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008081:Liposomes; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry*
chemical_list: D015700:HIV Envelope Protein gp41; D008081:Liposomes; D010446:Peptide Fragments
vernacular_title: Sliianie otritsatel'no zariazhennykh liposom pod deĭstviem peptidov iz N-kontsevogo fragmenta transmembrannogo belka VICh-1.