title: Peptide-poly(L-lysine citramide) conjugates and their in vitro anti-HIV behavior.
abstract: Poly(L-lysine citramide) is a degradable bioresorbable polyanion whose polyamide chains are composed of citric acid and L-lysine building blocks. Its chemical and physicochemical properties were extensively investigated in the past for its interest as polymeric drug carrier. In this work, 4(S)-amino-3-(S)-hydroxy-5-phenylpentanoyl-isoleucyl-phenylalanine methyl ester, a pseudopeptide active against the HIV protease in vitro, was linked to poly(L-lysine citramide) in attempts to promote solubility and cell penetration. Conjugates were characterized by FTIR, NMR, SEC, DLS, amino-acid analyses, and toxicity in mice. They degraded slowly at pH 7.4 and more rapidly at pH 4.5, two pH values selected to mimic extra-cellular fluids and intralysosome medium, respectively. According to capillary zone electrophoresis, degradation did not release the peptide. The phenylalanyl-isoleucyl-phenylalanine methyl ester peptide, inactive against the protease in vitro, was used as negative control. The anti-HIV activities of the carrier, of the conjugates and of model molecules, including a fluorescence-labeled pseudopeptide conjugate, were evaluated comparatively in vitro using two cell lines, namely, CEM-SS and MT-4 cells, infected with HIV-1 LAI and IIIB isolates, respectively. Unexpectedly, all the conjugates showed in vitro antiviral activity independent of peptide release and of inhibition of the HIV protease. According to FACS analysis, the antiviral activity was related to the presence of peptide moieties along the polymer chains and depended on the order by which cells, viruses, and conjugates were presented to each other. Although it was not possible to determine whether the antiviral activity resulted from interactions between conjugates and cells or conjugates and virus or both, the conjugates appeared able to inhibit the binding of the virus to cells in vitro when introduced before cell infection. None of the conjugates exhibited acute toxicity in mice.
authors.affiliation: Research Centre on Artificial Biopolymers, UMR CNRS 5473, Faculty of Pharmacy, University Montpellier 1, 15 Avenue Charles Flahault, BP 14491, F-34093 Montpellier Cedex 2, France.
authors.forename: Anne-Claude
authors.initials: AC
authors.lastname: Couffin-Hoarau
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Aubertin
authors.forename: Mahfoud
authors.initials: M
authors.lastname: Boustta
authors.forename: Sylvie
authors.initials: S
authors.lastname: Schmidt
authors.forename: Jean-Alain
authors.initials: JA
authors.lastname: Fehrentz
authors.forename: Jean
authors.initials: J
authors.lastname: Martinez
authors.forename: Michel
authors.initials: M
authors.lastname: Vert
mesh_terms: D000818:Animals; D019380:Anti-HIV Agents / Q000737:chemistry / Q000494:pharmacology*; D001835:Body Weight / Q000187:drug effects; D002460:Cell Line; D002855:Chromatography, Thin Layer; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D015658:HIV Infections / Q000188:drug therapy*; D017320:HIV Protease Inhibitors / Q000737:chemistry / Q000494:pharmacology; D015497:HIV-1 / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D020128:Inhibitory Concentration 50; D008214:Lymphocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D008239:Lysine / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D010446:Peptide Fragments / Q000737:chemistry / Q000494:pharmacology*; D011107:Polylysine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D011108:Polymers; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D019380:Anti-HIV Agents; D017320:HIV Protease Inhibitors; D010446:Peptide Fragments; D011108:Polymers; C510489:poly(lysine citramide); D011107:Polylysine; D008239:Lysine