Lipid-Derived Electrophiles Modify Proteins and Alter Their Interfacial Behavior: The Distinct Mediating Role of the Interface.

Abstract

In interface-dominated systems (IDSs), lipid peroxidation (LPO) and interfacial protein arrangement commonly coexist. Although lipid-derived electrophiles (LDEs), especially α,β-unsaturated aldehydes, extensively modify proteins, the specific role of interfaces in promoting such modification and its effect on protein behavior remains unclear. Here, we synthesized a yne-ACR probe to simulate LDEs and investigated its modification effect on whey protein (WP) in an IDS model comprising n-hexadecane (Hex) and water. Interface hydromechanics results reveal that the interface distinctly mediates protein modification by yne-ACR in the IDS model. Both the yne-ACR concentration and interfacial properties significantly affect protein interfacial behavior. The interface offers a unique environment for protein modification by yne-ACR, differing from homogeneous systems and producing varied aggregation behaviors between interfacial and nonadsorbed proteins. Chemical proteomic profiling identified 209 modified proteins at the interface compared to 156 in nonadsorbed systems, highlighting increased susceptibility of interfacial proteins to yne-ACR modification and subsequent changes in aggregation patterns. All-atom molecular dynamics (MD) simulations indicate that yne-ACR modification disrupts the stability of protein aggregates at interfaces, promoting redistribution between the interface and the bulk phases and modifying interfacial activity. These findings clarify how LDEs modify proteins in IDSs and their subsequent effects on interfacial behavior.