Molecular mechanism of succinylation-mediated inhibition of heat-induced egg white protein aggregation: Structural characterization and molecular dynamics simulations

Thermal aggregation of food proteins poses a significant challenge in liquid food systems, limiting their practical applications in food processing and formulation. This study investigates the mechanism by which succinylation enhances the thermal stability of egg white proteins (EWP). The results demonstrated succinylation effectively prevented heat-induced aggregation (90 °C, 30 min), maintaining over 80 % light transmittance. Molecular dynamics simulations revealed that succinylation disrupted key salt bridges (eg., K62-E254, E14-K227) and increased polar surface area from 13,836 to 20,338 Å², significantly altering protein-protein and protein-solvent interactions. These molecular changes were further confirmed by increased zeta potential (from −17.5 mV to −36.8 mV), enhanced β-sheet content (27.4 % to 40.0 %), and reduced surface hydrophobicity. As a result, the size of heat-induced aggregates decreased dramatically from 113.19 μm to 196.17 nm. These findings provide novel insights into the molecular basis of succinylation-enhanced protein thermal stability, offering valuable strategies for improving protein functionality in liquid food systems.