Inhibition of HIV budding by a genetically selected cyclic peptide targeting the Gag-TSG101 interaction

ACS Chem Biol. 2008 Dec 19;3(12):757-64. doi: 10.1021/cb800193n.

Abstract

The egress of HIV particles from virus-infected cells is accomplished by the recruitment of proteins that normally mediate host cell endocytic functions. This process requires interaction of the HIV Gag protein with the host protein TSG101 (tumor susceptibility gene 101). Here, we report the use of a bacterial reverse two-hybrid system to identify cyclic peptides that interfere with the Gag-TSG101 interaction and the finding that a five amino acid peptide discovered by this approach can disrupt the interaction and consequently inhibit HIV egress. The inhibiting molecule, which was selected from a cyclic peptide library containing approximately 3.2 x 10(6) members, differs in primary sequence from the interacting sites of either TSG101 or Gag. Addition of cyclic peptide tagged with an HIV Tat sequence, which previously has been shown to enhance protein translocation across plasma membranes, to cultured human cells inhibited the production of virus-like particles (VLPs) by these cells (IC(50) of 7 microM), and this inhibition occurred in the absence of adverse affects on normal endocytic functions mediated by TSG101. A mutant Gag protein not dependent on TSG101 for release was unaffected by the cyclic peptide. Our findings, which suggest that interference with the TSG101-Gag interaction by cyclic peptides may be of practical use in the treatment of HIV infections, identify a specific cyclic peptide that reduces VLP release by this mechanism; they also demonstrate that the efficiency of interference with protein-protein interactions by cyclic peptides can be enhanced by tagging the peptides with translocation-promoting sequences. Collectively our results support the notion that small molecule therapeutics that inhibit specific interactions between viral and host proteins may have general applicability in antiviral therapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-HIV Agents / chemical synthesis
  • Anti-HIV Agents / chemistry
  • Anti-HIV Agents / pharmacology*
  • Cells, Cultured
  • DNA-Binding Proteins / antagonists & inhibitors*
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / metabolism
  • Endosomal Sorting Complexes Required for Transport
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • HIV-1 / drug effects*
  • HIV-1 / genetics
  • HIV-1 / growth & development*
  • HIV-1 / metabolism
  • Humans
  • Ligands
  • Molecular Structure
  • Peptide Library
  • Peptides, Cyclic / chemical synthesis
  • Peptides, Cyclic / chemistry
  • Peptides, Cyclic / pharmacology*
  • Protein Binding
  • Structure-Activity Relationship
  • Transcription Factors / antagonists & inhibitors*
  • Transcription Factors / chemistry
  • Transcription Factors / metabolism
  • Two-Hybrid System Techniques
  • gag Gene Products, Human Immunodeficiency Virus / antagonists & inhibitors*
  • gag Gene Products, Human Immunodeficiency Virus / chemistry
  • gag Gene Products, Human Immunodeficiency Virus / metabolism

Substances

  • Anti-HIV Agents
  • DNA-Binding Proteins
  • Endosomal Sorting Complexes Required for Transport
  • Ligands
  • Peptide Library
  • Peptides, Cyclic
  • Transcription Factors
  • Tsg101 protein
  • gag Gene Products, Human Immunodeficiency Virus