Evolved Proteins Inhibit Entry of Enfuvirtide-Resistant HIV-1

ACS Infect Dis. 2019 Apr 12;5(4):634-640. doi: 10.1021/acsinfecdis.8b00362. Epub 2019 Mar 12.


Drugs that block HIV-1 entry are relatively limited. Enfuvirtide is a 36-residue synthetic peptide that targets gp41 and blocks viral fusion. However, Enfuvirtide-resistant HIV has been reported, and this peptide drug requires daily injection. Previously, we have reported helix-grafted display proteins, consisting of HIV-1 gp41 C-peptide helix grafted onto Pleckstrin Homology domains. Some of these biologics inhibit HIV-1 entry with relatively modest and varied potency (IC50 = 190 nM to >1 μM). Here, we report that gp41 C-peptide helix-grafted Sac7d (Sac7d-Cpep) potently suppresses HIV-1 entry in a live virus assay (IC50 = 1.9-12.4 nM). Yeast display sequence optimization of solvent exposed helix residues led to new biologics with improved expression in E. coli (a common biosimilar expression host), with no appreciable change in entry inhibition. Evolved proteins inhibit the entry of a clinically relevant mutant of HIV-1 that is gp41 C-peptide sensitive and Enfuvirtide resistant. Fusion proteins designed for serum stability also potently suppress HIV-1 entry. Collectively, we report several evolved biologics that are functional against an Enfuvirtide-resistant strain and are designed for serum stability.

Keywords: HIV; biologics; entry inhibitor; protein engineering; protein evolution.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Drug Resistance, Viral*
  • Enfuvirtide / pharmacology*
  • HIV Envelope Protein gp41 / chemistry*
  • HIV Envelope Protein gp41 / metabolism
  • HIV Fusion Inhibitors / pharmacology*
  • HIV Infections / virology
  • HIV-1 / drug effects*
  • HIV-1 / genetics
  • HIV-1 / physiology
  • Humans
  • Peptides / chemistry
  • Peptides / genetics
  • Peptides / pharmacology*
  • Protein Conformation, alpha-Helical
  • Protein Engineering
  • Virus Internalization / drug effects*


  • HIV Envelope Protein gp41
  • HIV Fusion Inhibitors
  • Peptides
  • Enfuvirtide