The Interaction between Xanthan Gum and Bovine Serum Albumin was Studied by Multispectral Method and Molecular Docking Simulation

Abstract

The interaction mechanism between xanthan gum (XG) and bovine serum albumin (BSA) was studied by various spectral and molecular docking techniques. The fluorescence spectrum analysis reveals that XG and BSA are quenched, with XG quenching BSA in a static manner according to the Stern-Volmer equation. The Vant’s Hoff equation indicates negative values for the thermodynamic parameters ΔH, ΔG, and ΔS during the binding process. Therefore, it can be concluded that hydrogen bonding and van der Waals forces dominate the interaction between XG and BSA, resulting in a spontaneous and exothermic quenching process. The results of molecular docking simulation show that hydrogen bond and van der Waals force are the main forces between XG and BSA. Through multispectral analysis, it is observed that XG affects the microenvironment of BSA by increasing its polarity and hydrophilicity while weakening its hydrophobicity. This leads to changes in the secondary structure of BSA molecules. The binding distance between XG and BSA is calculated to demonstrate energy transfer between them, and overlap integral calculations confirm the presence of non-radiative energy transfer from XG to BSA. Analysis of the circular dichroism spectrum reveals that interaction between BSA and XG leads to protein relaxation, a decrease in α-helix structure, and an increase in β-sheet structure, providing further evidence for alterations in the secondary structure of BSA. Through the study of the interaction between XG and BSA, the interaction mechanism of both is analyzed, which provides data support for their future discussion and research.