Interaction, bioaccessibility and stability of bovine serum albumin-gamma-oryzanol complex: Spectroscopic and computational approaches

Abstract

The study explored the interaction mechanism between bovine serum albumin (BSA) and gamma-oryzanol (GO) by spectroscopic and computational approaches and the potential to enhance bioaccessibility and chemical stability of GO in the complex with BSA. Fluorescence spectroscopy showed that GO was bound to BSA with static quenching at a single binding site, being consistent with molecular docking results. Thermodynamic analysis and molecular dynamics simulation showed that electrostatic forces dominated interactions between BSA and GO. Besides, BSA-GO complex was more stable at pH 7.4 than at pH 2.0, with low root-mean-square deviation (2.57 Å vs 12.37 Å) and low binding energy (-424.23 kJ/mol at 277 K vs -188.55 kJ/mol at 277 K), but complex stability significantly decreased with increasing temperature. The bioaccessibility and stability of GO in the complex were significantly higher than those in water. This study provided theoretical support for developing proteins as delivery system for GO.

Keywords: Binding mechanism; Chemical stability; Fluorescence spectroscopy; Molecular dynamics simulation; Thermodynamic parameters.