Bridged beta(3)-peptide inhibitors of p53-hDM2 complexation: correlation between affinity and cell permeability

J Am Chem Soc. 2010 Mar 10;132(9):2904-6. doi: 10.1021/ja910715u.

Abstract

Beta-peptides possess several features that are desirable in peptidomimetics; they are easily synthesized, fold into stable secondary structures in physiologic buffers, and resist proteolysis. They can also bind to a diverse array of proteins to inhibit their interactions with alpha-helical ligands. beta-peptides are usually not cell-permeable, however, and this feature limits their utility as research tools and potential therapeutics. Appending an Arg(8) sequence to a beta-peptide improves uptake but adds considerable mass. We previously reported that embedding a small cationic patch within a PPII, alpha-, or beta-peptide helix improves uptake without the addition of significant mass. In another mass-neutral strategy, Verdine, Walensky, and others have reported that insertion of a hydrocarbon bridge between the i and i + 4 positions of an alpha-helix also increases cell uptake. Here we describe a series of beta-peptides containing diether and hydrocarbon bridges and compare them on the basis of cell uptake and localization, affinities for hDM2, and 14-helix structure. Our results highlight the relative merits of the cationic-patch and hydrophobic-bridge strategies for improving beta-peptide uptake and identify a surprising correlation between uptake efficiency and hDM2 affinity.

Publication types

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

MeSH terms

  • Cell Membrane Permeability / drug effects*
  • Computer Simulation
  • HeLa Cells
  • Humans
  • Peptides / chemical synthesis
  • Peptides / chemistry
  • Peptides / pharmacology*
  • Proto-Oncogene Proteins c-mdm2 / antagonists & inhibitors*
  • Proto-Oncogene Proteins c-mdm2 / chemistry
  • Proto-Oncogene Proteins c-mdm2 / metabolism
  • Structure-Activity Relationship
  • Tumor Suppressor Protein p53 / antagonists & inhibitors*
  • Tumor Suppressor Protein p53 / chemistry
  • Tumor Suppressor Protein p53 / metabolism

Substances

  • Peptides
  • Tumor Suppressor Protein p53
  • MDM2 protein, human
  • Proto-Oncogene Proteins c-mdm2