Exploring the Binding Mode between Potassium Bromate and Bovine Serum Albumin: Multi-Spectroscopic and Molecular Modeling Analysis

Abstract Potassium bromate (PB) has been widely used as the least expensive dough improver and oxidizing agent in the baking industry. Due to its beneficial effects, it plays a significant role in the bread-making industry. However, due to its potential toxicity to human health, additional scrutiny is necessary. We examined the binding mode of potassium bromate and BSA using multi-spectroscopic and molecular modeling techniques to understand better the additive's physiological properties at the molecular level. Stern-Volmer demonstrated that the PB additive could be quenched by BSA intensity using a hybrid quenching procedure, validated by UV-vis absorption results. As the temperature increased, the binding constant values decreased from 2.93×106 to 9.34×103 (M-1), indicating that the PB-BSA complex's stability decreased as the temperature was raised. Additionally, thermodynamic variables and molecular docking suggested that PB binds spontaneously to BSA. Furthermore, van der Waals forces and hydrogen bonding contribute significantly to the PB-BSA complex's stability. Similarly, molecular modeling analysis indicated that the binding energy of bromate and chain A-BSA was -5.26 kJ mol-1, confirming its specificity for this protein.