Halophilic-Like Structural Architecture Dictates the Salt-Dependent Solubility and Rheology of Walnut Globulins

We elucidate the molecular identity and salt-responsive dynamics of walnut storage proteins. Aqueous processing disperses them primarily as protein storage vacuoles (PSVs) and their fragments. Upon complete seed coat removal, they are identified as globulins, exhibiting exceptional solubility (>96%) at 9-17% NaCl. Crucially, they possess a halophilic-like architecture: a highly charged, low-lysine surface isolating scattered hydrophobic sites. This unique topology fundamentally dictates their phase behaviors. In dilute systems, it anchors a resilient hydration shell that prevents aggregation. In concentrated PSV isolates (5-13% NaCl), this architecture triggers liquid-liquid phase separation (LLPS), mirroring the crowded intracellular environments of halophilic microorganisms. The resulting lubricating microdroplets uniquely liquefy the dense PSV paste. Conversely, at extreme salinities (≥17% NaCl), severe macromolecular crowding and dehydration disrupt this barrier, triggering multivalent cross-linking and rheological fracture. Ultimately, this halophilic-like architecture comprehensively governs the hyper-solubility, salt-induced LLPS, and anomalous macroscopic functionality of walnut globulins.