Integrated Multi-Spectroscopy and Molecular Dynamics Simulations to Explore the Interaction Mechanism of Phenolic Compounds and Sea Bass Myofibrillar Protein

Polyphenol compounds can modify myofibrillar proteins to improve the quality of fish and surimi. Nevertheless, research into the precise mechanisms of interaction between phenolic substances and sea bass myofibrillar proteins is lacking. This study aimed to explore the interaction mechanism between five phenolic compounds (caffeic acid (CFA), gallic acid (GA), chlorogenic acid (CHA), resveratrol (RES), and catechin (CAT)) with sea bass myofibrillar protein (MP). The results of UV–vis absorption spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, and fluorescence spectroscopy (namely, multi-spectroscopy) showed that all five phenolic compounds could spontaneously form new complexes with MP, with a binding molar ratio of 1:1. The interaction between CFA and MP is predominantly electrostatic, while the interaction between GA and MP is mainly hydrophobic. The rest of phenolic compounds and MP are mediated by hydrogen bonds and van der Waals forces. And molecular dynamics (MD) simulations indicated that CHA-myosin had the minimum root mean square deviation, while CFA-myosin had the smallest Rg value. In addition, the amino acid Lys-179 was the key residue for the interaction between five phenolic compounds and myosin. This study contributes to a better understanding of the interaction between phenolic compounds and sea bass MP, which could develop the processing of aquatic food products.