RESUMEN
Arachin (ARA) and resveratrol (RES) are the primary protein and bioactive compound in peanuts and their processed products. However, the mechanism of interaction between these two substances remained unclear. To investigate protein structural changes, conformational variations, and molecular mechanisms in the interaction between them, multispectral analysis and computational chemistry methods were employed. Experimental results confirmed that RES quenched ARA's intrinsic fluorescence through static quenching, indicating their interaction. Thermodynamic analysis revealed the interaction between them was endothermic, spontaneous, and primarily hydrophobic. Molecular dynamics (MD) simulations highlighted strong affinity between RES and ARA, with key amino acids (His425, Val426, Phe405, and Phe464) facilitating their interaction. RES binding increased stability without significant protein conformational changes. The independent gradient model based on Hirshfeld partition (IGMH) validated their interaction, emphasizing van der Waals (VDW) interactions and hydrogen bonds (H-bonds) as crucial for stable binding. This research lays a theoretical foundation for potential applications of ARA-RES complex products in the food industry.
RESUMEN
This study investigated the impact of ultrasound treatment on dioscorin, the primary storage protein found in yam tubers. Three key factors, namely ultrasound power, duration, and frequency, were focused on. The research revealed that ultrasound-induced cavitation effects disrupted non-covalent bonds, resulting in a reduction in α-helix and ß-sheet contents, decreased thermal stability, and a decrease in the apparent hydrodynamic diameter (Dh) of dioscorin. Additionally, previously hidden amino acid groups within the molecule became exposed on its surface, resulting in increased surface hydrophobicity (Ho) and zeta-potential. Under specific ultrasound conditions (200 W, 25 kHz, 30 min), Dh decreased while Ho increased, facilitating the adsorption of dioscorin molecules onto the oil-water interface. Molecular dynamics (MD) simulations showed that at lower frequencies and pressures, the structural flexibility of dioscorin's main chain atoms increased, leading to more significant fluctuations between amino acid residues. This transformation improved dioscorin's emulsifying properties and its oil-water interface affinity.