The structure of an MDM2–Nutlin-3a complex solved by the use of a validated MDM2 surface-entropy reduction mutant

Abstract

The p53-binding site of MDM2 holds great promise as a target for therapeutic intervention in MDM2-amplified p53 wild-type forms of cancer. Despite the extensive validation of this strategy, there are relatively few crystallographically determined co-complex structures for small-molecular inhibitors of the MDM2-p53 interaction available in the PDB. Here, a surface-entropy reduction mutant of the N-terminal domain of MDM2 that has been designed to enhance crystallogenesis is presented. This mutant has been validated by comparative ligand-binding studies using differential scanning fluorimetry and fluorescence polarization anisotropy and by cocrystallization with a peptide derived from p53. Using this mutant, the cocrystal structure of MDM2 with the benchmark inhibitor Nutlin-3a has been determined, revealing subtle differences from the previously described co-complex of MDM2 with Nutlin-2.

A redox mechanism underlying nucleolar stress sensing by nucleophosmin

“…The levels of p53 accumulation were also demonstrated by western blotting in NPM1 knockdown and restored cells that were exposed to Act.D and H 2 O 2 . Nutlin-3, an agent that directly disrupts the p53–HDM2 interaction40, was used here as a positive control. Interestingly, Act.D or H 2 O 2 did not produce p53 accumulation in cells bearing C275S NPM1, whereas Nutlin-3 did (Fig.…”

Pathological Unfoldomics of Uncontrolled Chaos: Intrinsically Disordered Proteins and Human Diseases

“…(B) Crystal structure of MDM2 in complex with the inhibitor nutlin 3a (PDB entry 4HG7). 378 The orientation is the same as in panel A. The rigid cis -imidazoline scaffold mimics key hydrophobic interactions made by the p53 helix.…”

Structure of a Stapled Peptide Antagonist Bound to Nutlin-Resistant Mdm2

“…The M06 structure was further compared to the crystal structures of a stapled p53 peptide (SAH-8) bound to Mdm2 (PDB 3V3B) [25] and to Nutlin bound to Mdm2 (PDB 4HGZ) [26] (Figure 4). The M06 stapled peptide forms interactions very similar to those made by the SAH-8 peptide, including the reorientation of the L26 side chain that appears to be associated with increased helicity.…”