Cellular Uptake and Ultrastructural Localization Underlie the Pro-apoptotic Activity of a Hydrocarbon-stapled BIM BH3 Peptide

ACS Chem Biol. 2015 Sep 18;10(9):2149-57. doi: 10.1021/acschembio.5b00214. Epub 2015 Jul 21.

Abstract

Hydrocarbon stapling has been applied to restore and stabilize the α-helical structure of bioactive peptides for biochemical, structural, cellular, and in vivo studies. The peptide sequence, in addition to the composition and location of the installed staple, can dramatically influence the properties of stapled peptides. As a result, constructs that appear similar can have distinct functions and utilities. Here, we perform a side-by-side comparison of stapled peptides modeled after the pro-apoptotic BIM BH3 helix to highlight these principles. We confirm that replacing a salt-bridge with an i, i + 4 hydrocarbon staple does not impair target binding affinity and instead can yield a biologically and pharmacologically enhanced α-helical peptide ligand. Importantly, we demonstrate by electron microscopy that the pro-apoptotic activity of a stapled BIM BH3 helix correlates with its capacity to achieve cellular uptake without membrane disruption and accumulate at the organellar site of mechanistic activity.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Apoptosis / drug effects*
  • Apoptosis Regulatory Proteins / chemistry*
  • Apoptosis Regulatory Proteins / pharmacokinetics
  • Apoptosis Regulatory Proteins / pharmacology*
  • Bcl-2-Like Protein 11
  • Cell Line
  • Hydrocarbons / chemistry*
  • Hydrocarbons / pharmacokinetics
  • Hydrocarbons / pharmacology*
  • Membrane Proteins / chemistry*
  • Membrane Proteins / pharmacokinetics
  • Membrane Proteins / pharmacology*
  • Mice
  • Molecular Sequence Data
  • Peptides / chemistry*
  • Peptides / pharmacokinetics
  • Peptides / pharmacology*
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • Proto-Oncogene Proteins / chemistry*
  • Proto-Oncogene Proteins / pharmacokinetics
  • Proto-Oncogene Proteins / pharmacology*

Substances

  • Apoptosis Regulatory Proteins
  • Bcl-2-Like Protein 11
  • Bcl2l11 protein, mouse
  • Hydrocarbons
  • Membrane Proteins
  • Peptides
  • Proto-Oncogene Proteins