Bridged beta(3)-peptide inhibitors of p53-hDM2 complexation: correlation between affinity and cell permeability.
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.
Bautista
Arjel D
AD
Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, USA.
Appelbaum
Jacob S
JS
Craig
Cody J
CJ
Michel
Julien
J
Schepartz
Alanna
A
D002463:Cell Membrane Permeability / Q000187:drug effects*; D003198:Computer Simulation; D006367:HeLa Cells; D006801:Humans; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D051736:Proto-Oncogene Proteins c-mdm2 / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D013329:Structure-Activity Relationship; D016159:Tumor Suppressor Protein p53 / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism
D010455:Peptides; D016159:Tumor Suppressor Protein p53; C497206:MDM2 protein, human; D051736:Proto-Oncogene Proteins c-mdm2