The Effect of Trilobatin on Bovine Serum Albumin: Interaction Mechanism and Molecular Docking

Understanding the transport and distribution of small molecules in vivo is aided by studying their interactions with proteins. As a natural sweetener, trilobatin possesses several biological activities. However, uncertainty surrounds the trilobatin and Bovine Serum Albumin (BSA) interaction mechanism. In this study, the binding types, number of binding sites and binding constants of trilobatin interaction with BSA were studied by fluorescence spectrometry. The effect of trilobatin on the spatial conformation of BSA was investigated using FT-IR, fluorescence and UV-V is absorption spectra. Moreover, the molecular docking method was employed to research the exact binding model of trilobatin and BSA. Findings from this investigation demonstrated that static quenching was the method by which trilobatin suppressed the fluorescence of BSA. The binding constants Ka of trilobatin and BSA at 298, 304 and 310 K were 2.23×10⁴, 3.06×10⁴ and 6.39×10⁴ moL/L, respectively and only a single site of BSA was bound to trilobatin. According to the discoveries of molecular simulation and thermodynamic analysis, the predominant forces between trilobatin and BSA were hydrogen bond and hydrophobic force (ΔH° >0 and ΔS° >0). Trilobatin and BSA had an endothermic, entropy-driven reaction during their binding contact (ΔG° >0). Additionally, non-radiative energy transfer took place among trilobatin and BSA because their binding distance was smaller than 7 nm. Moreover, trilobatin altered the microenvironment and conformation of BSA and formed the non-fluorescent ground state complex. Important data supporting trilobatin’s availability and distribution were supplied by this investigation.