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Updated: Aug 12, 2026
Purification of Ubiquitinated p53 Proteins from Mammalian Cells
Published on: March 21, 2022
Crystallographic analysis of an 8-mer p53 peptide analogue complexed with MDM2
Kaori Sakurai1, Carsten Schubert, Daniel Kahne
1Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, USA.
Abstract:
The most potent inhibitor of the p53-MDM2 interaction reported to date is an 8-mer p53 peptide analogue (Novartis peptide), which contains 6-chlorotryptophane (Cl-Trp) and phosphonomethylphenylalanine (Pmp) as key residues for the enhanced activity. We report here a crystal structure of the co-complex between MDM2 and the Novartis peptide solved at 1.8 A resolution. The structural basis for the role of the two aromatic residues are delineated by comparing the present structure with crystal structures of the MDM2 co-complex bound to other inhibitors including the wt-p53 peptide itself.
Insights
The Novartis peptide, a potent p53-MDM2 inhibitor, reveals its structural basis. Key residues 6-chlorotryptophane and phosphonomethylphenylalanine are crucial for its enhanced activity.
Area of Science:
- Biochemistry
- Structural Biology
- Drug Discovery
Background:
- The p53-MDM2 interaction is a critical target for cancer therapy.
- The Novartis peptide is a highly potent inhibitor of this interaction, featuring unique residues.
- Understanding the structural basis of inhibition is key to developing new therapeutics.
Purpose of the Study:
- To elucidate the crystal structure of the MDM2-Novartis peptide complex.
- To delineate the structural role of 6-chlorotryptophane (Cl-Trp) and phosphonomethylphenylalanine (Pmp) in inhibitor activity.
- To compare this structure with other p53-MDM2 inhibitor complexes.
Main Methods:
- X-ray crystallography
- Co-complex structure determination at 1.8 Å resolution
- Comparative structural analysis
Main Results:
- The crystal structure of the MDM2-Novartis peptide co-complex was determined at 1.8 Å resolution.
- The structural contributions of Cl-Trp and Pmp residues to binding affinity were identified.
- Key differences in binding compared to wild-type p53 peptide and other inhibitors were observed.
Conclusions:
- The structure provides a detailed understanding of how the Novartis peptide inhibits the p53-MDM2 interaction.
- The findings highlight the importance of specific modified residues for potent inhibition.
- This structural insight can guide the design of novel p53-MDM2 inhibitors for cancer treatment.
