alpha/beta-Peptide Foldamers Targeting Intracellular Protein-Protein Interactions with Activity in Living Cells Academic Article uri icon


  • Peptides can be developed as effective antagonists of protein-protein interactions, but conventional peptides (i.e., oligomers of l-α-amino acids) suffer from significant limitations in vivo. Short half-lives due to rapid proteolytic degradation and an inability to cross cell membranes often preclude biological applications of peptides. Oligomers that contain both α- and β-amino acid residues ("α/β-peptides") manifest decreased susceptibility to proteolytic degradation, and when properly designed these unnatural oligomers can mimic the protein-recognition properties of analogous "α-peptides". This report documents an extension of the α/β-peptide approach to target intracellular protein-protein interactions. Specifically, we have generated α/β-peptides based on a "stapled" Bim BH3 α-peptide, which contains a hydrocarbon cross-link to enhance α-helix stability. We show that a stapled α/β-peptide can structurally and functionally mimic the parent stapled α-peptide in its ability to enter certain types of cells and block protein-protein interactions associated with apoptotic signaling. However, the α/β-peptide is nearly 100-fold more resistant to proteolysis than is the parent stapled α-peptide. These results show that backbone modification, a strategy that has received relatively little attention in terms of peptide engineering for biomedical applications, can be combined with more commonly deployed peripheral modifications such as side chain cross-linking to produce synergistic benefits.


  • Checco, JW
  • Lee, EF
  • Evangelista, M
  • Sleebs, NJ
  • Rogers, K
  • Pettikiriarachchi, A
  • Kershaw, NJ
  • Eddinger, GA
  • Belair, DG
  • Wilson, JL
  • Eller, CH
  • Raines, RT
  • Murphy, WL
  • Smith, BJ
  • Gellman, SH
  • Fairlie, WD

publication date

  • 2015

has subject area