title: Inhibition of HIV infection by pseudopeptides blocking viral envelope glycoprotein-mediated membrane fusion and cell death.
abstract: The RP dipeptide motif is highly conserved in the third hypervariable region (V3 loop) of the extracellular envelope glycoprotein of different types of HIV isolates. In view of this, we have designed and synthesized a construction referred to as "template assembled synthetic peptide" (TASP), in which a lysine-rich short polypeptide was used as a template to covalently anchor arrays of tripeptides, such as RPR, RPK, or KPR. The pentavalent presentation, 5(RPR)-, 5(RPK)-, or 5(KPR)-TASP, molecules manifested maximum inhibitory activity on HIV infection with a 50% inhibitory concentration value of 1-5 microM, respectively. Structure and inhibitory-activity relationship studies using analogs of 5(KPR)-TASP indicated that the positively charged side chains of the K and R residues in the tripeptide molecules are critical for the optimal inhibitory activity of the pentavalent construct. Interestingly, replacement of L-amino acid residues by D-amino acids or reduction of the peptide bond between the first two amino acids of the tripeptide generated peptide-TASP analogs active at sub-microM, concentrations. The anti-HIV action of the peptide-TASP constructs is specific, since they inhibit infection of several types of CD4-expressing cells by HIV-1 Lai and HIV-2 EHO but not by the simian SIV-mac isolate. Our results suggest that these inhibitors block three post-CD4 binding functions of the HIV envelope glycoproteins, mediation of viral entry, syncytium formation, and triggering cell death by apoptosis. As the peptide-TASP derivatives with unnatural amino acid sequences in the tripeptide moiety retain full inhibitory activity, they should provide potent protease-resistant peptide inhibitors as potential therapeutic agents for treatment of AIDS patients.
authors.affiliation: Unité de Virologie et Immunologie Cellulaire, UA 1157 CNRS, Institut Pasteur, 25 rue du Dr Roux, Paris Cedex 15, 75724, France.
authors.forename: C
authors.initials: C
authors.lastname: Callebaut
authors.forename: E
authors.initials: E
authors.lastname: Jacotot
authors.forename: G
authors.initials: G
authors.lastname: Guichard
authors.forename: B
authors.initials: B
authors.lastname: Krust
authors.forename: M
authors.initials: M
authors.lastname: Rey-Cuille
authors.forename: D
authors.initials: D
authors.lastname: Cointe
authors.forename: N
authors.initials: N
authors.lastname: Benkirane
authors.forename: J
authors.initials: J
authors.lastname: Blanco
authors.forename: S
authors.initials: S
authors.lastname: Muller
authors.forename: J
authors.initials: J
authors.lastname: Briand
authors.forename: A G
authors.initials: AG
authors.lastname: Hovanessian
mesh_terms: D000595:Amino Acid Sequence; D000998:Antiviral Agents / Q000737:chemistry / Q000494:pharmacology*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D015699:HIV Envelope Protein gp120 / Q000187:drug effects* / Q000502:physiology; D015497:HIV-1 / Q000187:drug effects*; D015498:HIV-2 / Q000187:drug effects*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000821:virology; D008561:Membrane Fusion / Q000187:drug effects; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010446:Peptide Fragments / Q000187:drug effects* / Q000502:physiology; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology*; D015302:Simian Immunodeficiency Virus / Q000187:drug effects
chemical_list: D000998:Antiviral Agents; D015699:HIV Envelope Protein gp120; C059762:HIV envelope protein gp120 (305-321); D010446:Peptide Fragments; D010455:Peptides