Design of a novel peptide inhibitor of HIV fusion that disrupts the internal trimeric coiled-coil of gp41

J Biol Chem. 2002 Apr 19;277(16):14238-45. doi: 10.1074/jbc.M201453200. Epub 2002 Feb 21.


The pre-hairpin intermediate of gp41 from the human immunodeficiency virus (HIV) is the target for two classes of fusion inhibitors that bind to the C-terminal region or the trimeric coiled-coil of N-terminal helices, thereby preventing formation of the fusogenic trimer of hairpins. Using rational design, two 36-residue peptides, N36(Mut(e,g)) and N36(Mut(a,d)), were derived from the parent N36 peptide comprising the N-terminal helix of the gp41 ectodomain (residues 546-581 of HIV-1 envelope), characterized by analytical ultracentrifugation and CD, and assessed for their ability to inhibit HIV fusion using a quantitative vaccinia virus-based fusion assay. N36(Mut(e,g)) contains nine amino acid substitutions designed to disrupt interactions with the C-terminal region of gp41 while preserving contacts governing the formation of the trimeric coiled-coil. N36(Mut(a,d)) contains nine substitutions designed to block formation of the trimeric coiled-coil but retains residues that interact with the C-terminal region of gp41. N36(Mut(a,d)) is monomeric, is largely random coil, does not interact with the C34 peptide derived from the C-terminal region of gp41 (residues 628-661), and does not inhibit fusion. The trimeric coiled-coil structure is therefore a prerequisite for interaction with the C-terminal region of gp41. N36(Mut(e,g)) forms a monodisperse, helical trimer in solution, does not interact with C34, and yet inhibits fusion about 50-fold more effectively than the parent N36 peptide (IC(50) approximately 308 nm versus approximately 16 microm). These results indicate that N36(Mut(e,g)) acts by disrupting the homotrimeric coiled-coil of N-terminal helices in the pre-hairpin intermediate to form heterotrimers. Thus N36(Mut(e,g)) represents a novel third class of gp41-targeted HIV fusion inhibitor. A quantitative model describing the interaction of N36(Mut(e,g)) with the pre-hairpin intermediate is presented.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Anti-HIV Agents / pharmacology*
  • Circular Dichroism
  • Dose-Response Relationship, Drug
  • Drug Design*
  • HIV / metabolism*
  • HIV Envelope Protein gp41 / chemistry*
  • Models, Biological
  • Molecular Sequence Data
  • Peptides / chemistry
  • Protein Conformation / drug effects
  • Protein Structure, Tertiary
  • Ultracentrifugation


  • Anti-HIV Agents
  • HIV Envelope Protein gp41
  • Peptides