A critical assessment of the synthesis and biological activity of p53/human double minute 2‐stapled peptide inhibitors

• DOI: 10.1111/bph.13834
• Publication Date: 2017-04-24T03:16:52Z
• Authors: Rike Wallbrecher; Patrick Chène; Stephan Ruetz; Therese Stachyra; Thomas Vorherr; Roland Brock
• Keywords: 0301 basic medicine; 03 medical and health sciences; HEK293 Cells; Radboudumc 19: Nanomedicine RIMLS: Radboud Institute for Molecular Life Sciences; Cell Line, Tumor; Humans; Proto-Oncogene Proteins c-mdm2; Tumor Suppressor Protein p53; Biochemistry - Radboud University Medical Center; Peptides

Background and Purpose Helix stapling enhances the activity of peptides that interact with a target protein in helical conformation. These staples are also supposed to change pharmacokinetics molecules promote cytoplasmic targeting. We assessed extent which pharmacokinetic characteristics function staple for peptide inhibiting interaction p53 human double minute 2 (Hdm2) differ from those standard cationic cell‐penetrating nona‐arginine. Experimental Approach Stapled linear counterparts were synthesized free fluorescently labelled forms. Activity was determined biochemical time‐resolved Förster resonance energy transfer experiments cellular high‐content assays. Cellular uptake intracellular trafficking visualized by confocal microscopy. Key Results Peptides showed sub‐nanomolar potency. For short‐time incubation, efficiencies stapled similar both taken up less efficiently than Only SJSA‐1 cells expressing Hdm2 protein, an enhanced nuclear accumulation after long‐term incubation. This observed counterparts, albeit lesser degree. HeLa cells, lack expression, no such observed. Conclusion Implications Cytosolic not intrinsic property peptide, but resulted capture endo‐lysosomal release. Considering rather poor peptides, further development should focus on increasing efficiency these peptides.