A Potential MDM2 Inhibitor Formed by Restoring the Native Conformation of the p53 α‐Helical Peptide on Gold Nanoparticles

Abstract

Many efforts have been made to develop inhibitors of MDM2 as potential drugs for cancer therapy. In this work, we use our previous developed conformational engineering technique to stabilize the binding conformation of the p53 transcription activation domain (TAD) peptide on gold nanoparticles (AuNPs), and create an AuNP‐based anti‐MDM2 artificial antibody, denoted as anti‐MDM2 Goldbody, that specifically binds MDM2. Though the free TAD peptide is unstructured, circular dichroism (CD) spectra confirm that its α‐helical conformation in the original p53 protein is restored on the anti‐MDM2 Goldbody, and surface plasmon resonance (SPR) experiments confirm that there is strong specific interaction between the anti‐MDM2 Goldbody and MDM2, demonstrating the anti‐MDM2 Goldbody as a potential inhibitor of MDM2. This work demonstrates that the conformational engineering technique is not limited to the antigen‐antibody systems, but can also be applied more widely in other protein‐protein interfaces to create increasingly more artificial proteins for various biomedical applications.

Conformationally engineering flexible peptides on silver nanoparticles

“…Together with previous Goldbodies ( Liu et al., 2022 ; Luo et al., 2020 ; Yan et al., 2018 ), the current success of Silverbody highlights the general possibility of conformational engineering on NPs. Though molecular conformational engineering is still in its infancy, some principles might be concluded from the successes of Goldbody and Silverbody, as well as from the theoretical consideration.…”

“…If the conformational engineering technique, which was originally developed for Goldbody on AuNPs ( Liu et al., 2022 ; Luo et al., 2020 ; Yan et al., 2018 ), would also effectively work on AgNPs, then AgNP-60P1 would directly bind into the active cleft of HEWL, inhibiting the enzymatic activity of HEWL. Fortunately, AgNP-60P1 did inhibit the activity of HEWL ( Figure 3 A), demonstrating that the conformational engineering technique worked well on AgNPs too.…”

“…As mentioned previously, a distinguishable feature of the current conformational engineering is the two anchoring positions for each peptide on NPs. The first advantage of the two anchors is to greatly reduce the entropy of the non-native state of the peptide by excluding a large number of conformations ( Liu et al., 2022 ). As the free peptide fragment (e.g.…”

“…Even for these molecules, they can only be conformationally engineered into those favorable conformations (energy minima). It has to be pointed out that the goal for conformational engineering is not necessarily the one with the lowest energy, so both conformations #1 and #2 in Figure 6 C are the possible conformations, just like that the same peptide fragment could adopt different native conformations in different proteins or at different conditions ( Liu et al., 2022 ; Luo et al., 2020 ).

Figure 6 Typical energy landscapes of molecules with large conformation space (A) Molecules with an energy landscape too shallow.

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“…Usually, after the proper peptide fragment is selected from natural proteins, it has to be properly modified, such as the mutation of strong binding residues (e.g. Cys, Lysine, and Arginine) to prevent the strong interaction with NPs at unwanted positions, and the incorporation of Cys residues at suitable positions in order to form at least two M-S bonds with NPs ( Liu et al., 2022 ; Luo et al., 2020 ; Yan et al., 2018 ).…”