As the most abundant protein existing in fish, myofibrillar protein (MP) is likely to hydrolyze which affects the quality of fish during preservation. Polyphenols, which are some of the most popular antioxidants and antimicrobials, have been widely used in freshwater fish preservation and storage to prevent protein degradation. However, their binding behavior and mechanism is still unclear. In this study, the binding mechanisms of two types of polyphenols (chlorogenic acid (CGA); quercetin (QUE)) and MP extracted from grass carp were investigated through multi-spectroscopic methods. Different spectroscopic methods (fluorescence spectroscopy and synchronous fluorescence spectroscopy) were used to explore the interaction modes between polyphenols and fish-extracted MP. In addition, circular dichroism spectroscopy was used to detect microstructure changes of MP under different preservation approaches. Results showed that nanocomposites were generated when MP interacted with either CGA or QUE. The addition of CGA did not affect the α-helix content of MP, whereas QUE diffused the β-turns of myofibrillar proteins and promoted the formation of α-helices. At the same time, the fluorescence-quenching effect of CGA/QUE on MP was static quenching, and the binding constants, number of binding sites, and corresponding thermodynamic parameters of MP were calculated. It was concluded that the binding of CGA to MP depends on Van der Waals forces and hydrogen bonds, while QUE binds to MPs on the basis of electrostatic interactions. In addition, the fluorescence quenching of MPs with CGA is related to tryptophan and tyrosine residues, while the fluorescence-quenching effect of QUE on MPs is related only to tryptophan residues.

作为鱼类中存在的最丰富的蛋白质，肌原纤维蛋白（MP）可能会水解，从而影响保存过程中鱼类的质量。多酚是一些最流行的抗氧化剂和抗菌剂，已广泛用于淡水鱼的保存和存储中，以防止蛋白质降解。但是，它们的结合行为和机理仍不清楚。本研究通过多光谱方法研究了从草鱼中提取的两种多酚（绿原酸（CGA）；槲皮素（QUE））和MP的结合机理。不同的光谱方法（荧光光谱法和同步荧光光谱法）被用来探索多酚和鱼提取的多巴胺之间的相互作用模式。此外，圆二色光谱用于检测在不同保存方法下MP的微观结构变化。结果表明，当MP与CGA或QUE相互作用时，会生成纳米复合材料。CGA的添加不影响MP的α-螺旋含量，而QUE使肌原纤维蛋白的β-转角扩散并促进α-螺旋的形成。同时，CGA / QUE对MP的荧光猝灭作用为静态猝灭，计算了MP的结合常数，结合位点数和相应的热力学参数。结论是，CGA与MP的结合取决于范德华力和氢键，而QUE基于静电相互作用与MP结合。此外，用CGA对MP进行荧光猝灭与色氨酸和酪氨酸残基有关，