title: Rationally designed interfacial peptides are efficient in vitro inhibitors of HIV-1 capsid assembly with antiviral activity.
abstract: Virus capsid assembly constitutes an attractive target for the development of antiviral therapies; a few experimental inhibitors of this process for HIV-1 and other viruses have been identified by screening compounds or by selection from chemical libraries. As a different, novel approach we have undertaken the rational design of peptides that could act as competitive assembly inhibitors by mimicking capsid structural elements involved in intersubunit interfaces. Several discrete interfaces involved in formation of the mature HIV-1 capsid through polymerization of the capsid protein CA were targeted. We had previously designed a peptide, CAC1, that represents CA helix 9 (a major part of the dimerization interface) and binds the CA C-terminal domain in solution. Here we have mapped the binding site of CAC1, and shown that it substantially overlaps with the CA dimerization interface. We have also rationally modified CAC1 to increase its solubility and CA-binding affinity, and designed four additional peptides that represent CA helical segments involved in other CA interfaces. We found that peptides CAC1, its derivative CAC1M, and H8 (representing CA helix 8) were able to efficiently inhibit the in vitro assembly of the mature HIV-1 capsid. Cocktails of several peptides, including CAC1 or CAC1M plus H8 or CAI (a previously discovered inhibitor of CA polymerization), or CAC1M+H8+CAI, also abolished capsid assembly, even when every peptide was used at lower, sub-inhibitory doses. To provide a preliminary proof that these designed capsid assembly inhibitors could eventually serve as lead compounds for development of anti-HIV-1 agents, they were transported into cultured cells using a cell-penetrating peptide, and tested for antiviral activity. Peptide cocktails that drastically inhibited capsid assembly in vitro were also able to efficiently inhibit HIV-1 infection ex vivo. This study validates a novel, entirely rational approach for the design of capsid assembly interfacial inhibitors that show antiviral activity.
authors.affiliation: Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Madrid, Spain.
authors.forename: Rebeca
authors.initials: R
authors.lastname: Bocanegra
authors.forename: María
authors.initials: M
authors.lastname: Nevot
authors.forename: Rosa
authors.initials: R
authors.lastname: Doménech
authors.forename: Inmaculada
authors.initials: I
authors.lastname: López
authors.forename: Olga
authors.initials: O
authors.lastname: Abián
authors.forename: Alicia
authors.initials: A
authors.lastname: Rodríguez-Huete
authors.forename: Claudio N
authors.initials: CN
authors.lastname: Cavasotto
authors.forename: Adrián
authors.initials: A
authors.lastname: Velázquez-Campoy
authors.forename: Javier
authors.initials: J
authors.lastname: Gómez
authors.forename: Miguel Ángel
authors.initials: MÁ
authors.lastname: Martínez
authors.forename: José Luis
authors.initials: JL
authors.lastname: Neira
authors.forename: Mauricio G
authors.initials: MG
authors.lastname: Mateu
mesh_terms: D000595:Amino Acid Sequence; D019380:Anti-HIV Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D001665:Binding Sites; D002213:Capsid / Q000187:drug effects* / Q000378:metabolism*; D036022:Capsid Proteins / Q000737:chemistry / Q000378:metabolism; D002460:Cell Line; D015195:Drug Design; D015497:HIV-1 / Q000187:drug effects* / Q000378:metabolism* / Q000472:pathogenicity; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D055503:Protein Multimerization / Q000187:drug effects; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012995:Solubility
chemical_list: D019380:Anti-HIV Agents; D036022:Capsid Proteins; D010446:Peptide Fragments