Elucidation on the interaction between ascorbic acid and β-lactoglobulin based on multi-spectroscopic analysis and molecular simulation approach

Abstract

The binding mechanism between Ascorbic acid (AscA) and β-lactoglobulin (β-Lg) was thoroughly examined in this study using a variety of techniques, such as multi-spectroscopic analysis, thermodynamic measurements, molecular docking, and MD simulation at pH 7.4. The results indicated that the protein AscA was able to interact with the protein β-Lg, which led to a decrease in the fluorescence intensity of β-Lg. The interaction between AscA and β-Lg resulted in a decrease in the hydrophobicity of the local environment surrounding the tryptophan and tyrosine residues within the β-Lg protein. Additionally, changes in the secondary structure of the β-Lg protein were observed using Circular dichroism (CD), Fourier-transform infrared spectroscopy (FTIR), and simulation techniques. These structural changes were consistent with the calculated Tm analysis, Root means square deviation (RMSD), Radius of Gyration (RG), and solvent-accessible surface area (SASA) parameters. The analysis of fluorescence spectroscopy suggested that the formation of the β-Lg-(AscA) complex relies heavily on hydrogen and van der Waals interactions. The findings from this study offer new insights into the interaction mechanism between the β-Lg and AscA proteins. The results suggest that β-Lg can be utilized as a delivery vehicle for AscA in functional food applications.