title: Antiviral activity of α-helical stapled peptides designed from the HIV-1 capsid dimerization domain.
abstract: BACKGROUND
  The C-terminal domain (CTD) of HIV-1 capsid (CA), like full-length CA, forms dimers in solution and CTD dimerization is a major driving force in Gag assembly and maturation. Mutations of the residues at the CTD dimer interface impair virus assembly and render the virus non-infectious. Therefore, the CTD represents a potential target for designing anti-HIV-1 drugs.
  
  
  RESULTS
  Due to the pivotal role of the dimer interface, we reasoned that peptides from the α-helical region of the dimer interface might be effective as decoys to prevent CTD dimer formation. However, these small peptides do not have any structure in solution and they do not penetrate cells. Therefore, we used the hydrocarbon stapling technique to stabilize the α-helical structure and confirmed by confocal microscopy that this modification also made these peptides cell-penetrating. We also confirmed by using isothermal titration calorimetry (ITC), sedimentation equilibrium and NMR that these peptides indeed disrupt dimer formation. In in vitro assembly assays, the peptides inhibited mature-like virus particle formation and specifically inhibited HIV-1 production in cell-based assays. These peptides also showed potent antiviral activity against a large panel of laboratory-adapted and primary isolates, including viral strains resistant to inhibitors of reverse transcriptase and protease.
  
  
  CONCLUSIONS
  These preliminary data serve as the foundation for designing small, stable, α-helical peptides and small-molecule inhibitors targeted against the CTD dimer interface. The observation that relatively weak CA binders, such as NYAD-201 and NYAD-202, showed specificity and are able to disrupt the CTD dimer is encouraging for further exploration of a much broader class of antiviral compounds targeting CA. We cannot exclude the possibility that the CA-based peptides described here could elicit additional effects on virus replication not directly linked to their ability to bind CA-CTD.
authors.affiliation: Laboratory of Molecular Modeling & Drug Design; Lindsley F, Kimball Research Institute of the New York Blood Center, 310 E 67th Street, New York, NY 10065, USA.
authors.forename: Hongtao
authors.initials: H
authors.lastname: Zhang
authors.forename: Francesca
authors.initials: F
authors.lastname: Curreli
authors.forename: Xihui
authors.initials: X
authors.lastname: Zhang
authors.forename: Shibani
authors.initials: S
authors.lastname: Bhattacharya
authors.forename: Abdul A
authors.initials: AA
authors.lastname: Waheed
authors.forename: Alan
authors.initials: A
authors.lastname: Cooper
authors.forename: David
authors.initials: D
authors.lastname: Cowburn
authors.forename: Eric O
authors.initials: EO
authors.lastname: Freed
authors.forename: Asim K
authors.initials: AK
authors.lastname: Debnath
mesh_terms: D000595:Amino Acid Sequence; D019380:Anti-HIV Agents / Q000737:chemistry / Q000494:pharmacology*; D002460:Cell Line; D003001:Cloning, Molecular; D015195:Drug Design; D005822:Genetic Vectors; D015497:HIV-1 / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D006801:Humans; D006838:Hydrocarbons / Q000737:chemistry; D008279:Magnetic Resonance Imaging; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D010456:Peptides, Cyclic / Q000138:chemical synthesis / Q000494:pharmacology*; D055503:Protein Multimerization; D017433:Protein Structure, Secondary; D014162:Transfection; D014771:Virion / Q000378:metabolism; D019065:Virus Assembly / Q000187:drug effects*; D054301:gag Gene Products, Human Immunodeficiency Virus / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D019380:Anti-HIV Agents; D006838:Hydrocarbons; D010456:Peptides, Cyclic; D054301:gag Gene Products, Human Immunodeficiency Virus