The restoration of mutant p53 stability is a highly sought-after strategy in targeted cancer therapy. This study presents a structure-based virtual screening and molecular dynamics approach to nominate FDA-approved drugs as candidate stabilizers of mutant p53 for downstream experimental validation. A virtual screening library of FDA-approved compounds was docked against three representative p53 mutants (7DHY, 7DHZ, and 7V97) to evaluate their binding potential. The prioritized candidates demonstrated consistent, multi-conformer binding affinities. Protein–ligand interaction profiling revealed that the candidate DB09280 possesses a highly dense interaction network, particularly against the V272M and R249S variants. Residue-level analysis of the G245S structural mutant showed that DB09280 uniquely engages His19, a crucial residue for zinc coordination, and forms stabilizing contacts with adjacent flexible loop residues, including ASN35 and PRO32. Subsequent 500 ns molecular dynamics simulations were consistent with DB09280 acting as a putative conformational clamp on the timescale sampled. The ligand-bound (holo) system exhibited substantially reduced global structural drift (RMSD) and attenuated local residue fluctuation (RMSF) within the core domain compared to the highly unstable apo state. Principal component analysis further indicated that DB09280 restricts the broad conformational sampling of the mutant into a stable, dominant basin within the sampled trajectory. Together, these computational findings nominate DB09280 as a promising candidate structural stabilizer of mutant p53 worthy of experimental follow-up. We emphasize that the in silico stabilization observed here is not equivalent to functional rescue of p53 transcriptional activity; biochemical, biophysical, and cell-based assays will be required to establish whether DB09280 restores wild-type-like DNA binding or tumor-suppressor function in mutant p53 contexts.
Mena Abdelsayed, Y. Boulaamane· International Journal of Mol...· 0 citations
Parkinson’s disease (PD) is characterised by the pathological aggregation of α-synuclein (α-syn) into Lewy body inclusions, yet no disease-modifying therapy exists. To address this, we developed an integrated computational pipeline combining quantitative structure–activity relationship (QSAR) modelling, structure-based virtual screening, molecular dynamics (MD) simulation, and molecular mechanics Poisson–Boltzmann surface area (MM-PBSA) binding free energy calculations to repurpose FDA-approved drugs as α-syn fibril inhibitors. Two complementary QSAR model families were trained on 501 α-syn binding affinity records from BindingDB: Morgan extended-connectivity fingerprint (ECFP4) classifiers and a frozen ChemBERTa-77M-MLM transformer encoder, each using Random Forest and Logistic Regression. The applicability domain (AD) was assessed using Morgan–Tanimoto similarity (Tc ≥ 0.40) and calibrated ChemBERTa cosine distance (θ ≤ 0.367). A three-stage funnel applying central nervous system (CNS) permeability filters, a consensus QSAR probability threshold (≥0.80), and AD gating reduced 2241 FDA-approved drugs to 205 candidates for AutoDock Vina 1.2.6 docking against two sites on the cryo-electron microscopy (cryo-EM) α-syn fibril structure, PDB 6SSX: the inter-protofilament cleft (Site 1) and the non-amyloid-beta component (NAC) groove (Site 2). The Morgan fingerprint models achieved an area under the receiver operating characteristic curve (AUROC) of up to 0.940 and a balanced accuracy of 0.810; the ChemBERTa models achieved an AUROC of 0.785 and a balanced accuracy of 0.728. Notably, ChemBERTa AD covered 76.8% of the FDA drugs versus only 5.5% for Morgan–Tanimoto, enabling broad-spectrum screening. The top docking candidates were Olaparib (−7.91 kcal/mol), Paliperidone (−7.75 kcal/mol), Niraparib (−7.18 kcal/mol), Dordaviprone (−7.06 kcal/mol), and Parecoxib (−6.89 kcal/mol). The MD simulations over 200 ns across three independent replicates confirmed stable NAC groove binding, and replicate-averaged MM-PBSA calculations yielded ΔG = −20.6 ± 1.9 kcal/mol for Olaparib at Site 2, −17.1 ± 0.9 kcal/mol for Risperidone, and −16.9 ± 0.8 kcal/mol for Paliperidone, reported as the mean ± standard error of the mean (SEM) across replicates. Olaparib additionally formed five hydrogen bonds in the representative pose, while MD trajectories maintained approximately 2–5 hydrogen bonds, together with a halogen bond within the NAC groove, the largest contact count of any screened compound. These findings identify Olaparib as a novel high-affinity repurposing lead, while Paliperidone and Risperidone are reported as chemically informative secondary NAC–groove binders rather than proposed antiparkinsonian therapeutics, given that their dopamine D2-antagonist pharmacology is clinically associated with drug-induced parkinsonism. All of the candidates warrant experimental validation via thioflavin-T fluorescence or nuclear magnetic resonance (NMR) spectroscopy.
Mena Abdelsayed, Y. Boulaamane· International Journal of Mol...· 0 citations
