Rational design of proteolytically stable, cell-permeable peptide-based selective Mcl-1 inhibitors

J Am Chem Soc. 2012 Sep 12;134(36):14734-7. doi: 10.1021/ja306864v. Epub 2012 Sep 4.


Direct chemical modifications provide a simple and effective means to "translate" bioactive helical peptides into potential therapeutics targeting intracellular protein-protein interactions. We previously showed that distance-matching bisaryl cross-linkers can reinforce peptide helices containing two cysteines at the i and i+7 positions and confer cell permeability to the cross-linked peptides. Here we report the first crystal structure of a biphenyl-cross-linked Noxa peptide in complex with its target Mcl-1 at 2.0 Å resolution. Guided by this structure, we remodeled the surface of this cross-linked peptide through side-chain substitution and N-methylation and obtained a pair of cross-linked peptides with substantially increased helicity, cell permeability, proteolytic stability, and cell-killing activity in Mcl-1-overexpressing U937 cells.

Publication types

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

MeSH terms

  • Cell Membrane Permeability / drug effects*
  • Humans
  • Models, Molecular
  • Molecular Structure
  • Myeloid Cell Leukemia Sequence 1 Protein
  • Peptides / chemistry
  • Peptides / pharmacology*
  • Proto-Oncogene Proteins c-bcl-2 / antagonists & inhibitors*
  • Proto-Oncogene Proteins c-bcl-2 / biosynthesis
  • Proto-Oncogene Proteins c-bcl-2 / metabolism
  • U937 Cells


  • Myeloid Cell Leukemia Sequence 1 Protein
  • Peptides
  • Proto-Oncogene Proteins c-bcl-2