Design of peptide-based inhibitors for human immunodeficiency virus type 1 strains resistant to T-20

J Biol Chem. 2009 Feb 20;284(8):4914-20. doi: 10.1074/jbc.M807169200. Epub 2008 Dec 10.


Enfuvirtide (T-20) is a fusion inhibitor that suppresses replication of human immunodeficiency virus (HIV) variants with multi-drug resistance to reverse transcriptase and protease inhibitors. It is a peptide derived from the C-terminal heptad repeat (C-HR) of HIV-1 gp41, and it prevents interactions between the C-HR and the N-terminal HR (N-HR) of gp41, thus interfering with conformational changes that are required for viral fusion. However, prolonged therapies with T-20 result in the emergence of T-20-resistant strains that contain primary mutations such as N43D in the N-HR of gp41 (where T-20 and C-HR bind) that help the virus escape at a fitness cost. Such variants often go on to acquire a secondary mutation, S138A, in the C-HR of gp41 region that corresponds to the sequence of T-20. We demonstrate here that the role of S138A is to compensate for the impaired fusion kinetics of HIV-1s carrying primary mutations that abrogate binding of T-20. To preempt this escape strategy, we designed a modified T-20 variant containing the S138A substitution and showed that it is a potent inhibitor of both T-20-sensitive and T-20-resistant viruses. Circular dichroism analysis revealed that the S138A provided increased stability of the 6-helix bundle. We validated our approach on another fusion inhibitor, C34. In this case, we designed a variant of C34 with the secondary escape mutation N126K and showed that it can effectively inhibit replication of C34-resistant HIV-1. These results prove that it is possible to design improved peptide-based fusion inhibitors that are efficient against a major mechanism of drug resistance.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Substitution
  • Drug Design
  • Drug Resistance, Multiple / drug effects*
  • Drug Resistance, Multiple / genetics
  • Drug Resistance, Viral / drug effects*
  • Drug Resistance, Viral / genetics
  • Enfuvirtide
  • HIV Envelope Protein gp41 / antagonists & inhibitors
  • HIV Envelope Protein gp41 / genetics
  • HIV Envelope Protein gp41 / metabolism
  • HIV Envelope Protein gp41 / pharmacology*
  • HIV Fusion Inhibitors / pharmacology*
  • HIV Infections / drug therapy*
  • HIV Infections / genetics
  • HIV Infections / metabolism
  • HIV-1 / physiology*
  • HeLa Cells
  • Humans
  • Mutation, Missense
  • Peptide Fragments / genetics
  • Peptide Fragments / pharmacology*
  • Virus Replication / drug effects*
  • Virus Replication / genetics


  • HIV Envelope Protein gp41
  • HIV Fusion Inhibitors
  • Peptide Fragments
  • gp41 protein, Human immunodeficiency virus 1
  • Enfuvirtide