Comparison in structure, physicochemical and emulsifying properties of alpha lactoglobulin and beta lactalbumin exposed to prior γ-oryzanol by the multi-spectroscopic and silico methods

In this work, effects of gamma-oryzanol (GO) on structure, physicochemical and emulsifying properties of alpha-lactalbumin (alpha-La) and (3-lactoglobulin ((3-Lg) were compared by using multi-spectroscopic analysis and computer simulation. Specifically, the intrinsic fluorescence of both whey proteins was quenched by GO, with GO being a stronger quenching for (3-Lg than for alpha-La. The addition of GO caused the backbone of alpha-La to become denser, whereas for (3-Lg, its spatial structure shifted from ordered to disordered after the addition of GO. Additionally, the surface hydrophobicity, emulsifying properties, and DPPH free radical scavenging capacity of (3-Lg were higher than alpha-La after the addition of GO. Molecular docking indicated that the primary driving force in the whey protein-GO system was hydrophobic force. The hydrophobic pocket at the cleft between two structural domains in (3-Lg and alpha-La was the binding area for GO, and GO had greater binding affinity for (3-Lg than alpha-La. Furthermore, molecular dynamics simulations demonstrated that (3-Lg-GO system was more stabilized than alpha-LaGO system. This research contributed to a deeper understanding of the mechanisms by which alpha-La and (3-Lg interact with GO, offering the potential to develop whey protein-GO complexes as novel emulsifiers.