Cancer-linked aggregation of p53 is driven by sequence-encoded frustration, solvation, and hydrophobic gating absent in its paralogs

Tumor suppressor p53 is uniquely prone to misfolding and aggregation, a property tightly linked to oncogenic mutations and absent in its paralogs, p63 and p73. Yet, the biophysical origins underlying divergent aggregation propensity remain incompletely understood. Here, we integrate fluorescence spectroscopy, high-pressure and chemical denaturation NMR, molecular dynamics simulations, and energetic frustration analysis to dissect the structural and dynamic discrepancies among p53 and its paralogs. Our results reveal that p53 harbors distinct surface-exposed solvation patches and cavity-prone regions promoting local conformational plasticity. Residue-level NMR analysis uncovers a broad, asymmetric distribution of signal intensity changes with pressure, correlating with discrete solvation patches and frustration-prone regions. These features coincide with highly frustrated contact networks and altered hydrophobic core gating, collectively facilitating aggregation-prone states. In contrast, p63 and p73 exhibit more uniform solvation, reduced frustration, and tighter core packing, conferring greater structural stability. These mechanistic differences directly link uneven hydration and compressibility to the heightened amyloid aggregation propensity of p53C. These contrasting energetic landscapes illustrate how evolutionary sequence divergence fine-tunes p53 for functional flexibility at the expense of stability, predisposing it to pathological aggregation. Our findings illuminate the structural determinants that distinguish pathological folding in p53 and may guide therapeutic stabilization strategies.