Abstract：
The denaturation of proteins (particularly myosin) due to freezing can lead to the deterioration of Penaeus vannamei. The purpose of this study was to verify the antifreeze protective effects of polyphenols screened by a molecular docking technique, and to explore their interactions with myosin after freezing treatment. It was found that the screened polyphenols could significantly increase the freezing rate and unfreezable water content of shrimp paste. The results of fluorescence spectra indicated that the hesperetin to myosin quenching process included both dynamic and static quenching, and it was primarily bound to myosin through hydrophobic interactions; The quenching of myosin by both dihydroquercetin and mangiferin was static quenching, and they were bound to myosin mainly by hydrogen bonds and van der Waals forces; All three of these polyphenols had only one binding site on myosin. Surface hydrophobicity indicated that all four polyphenols were engaged in non-covalent binding (hydrophobic interactions) with myosin. Infrared spectra demonstrated that the addition of these four polyphenols significantly increased the α-helix content of myosin. They also reduced the myosin particle size, zeta potential, and protein degeneration degree. Scanning electron microscopy revealed that the four polyphenols reduced the degree of aggregation, while more uniformly distributing the myosin particles. These observations provide a basis for the screening of polyphenols and further research into the protective mechanism of polyphenols on frozen myosin.
摘要：
由于冷冻而导致的蛋白质（特别是肌球蛋白）变性可导致南美白对虾的恶化。本研究的目的是验证通过分子对接技术筛选的多酚的防冻保护作用。并探讨冷冻治疗后它们与肌球蛋白的相互作用。发现筛选的多酚可以显着提高虾酱的冷冻速率和不可冷冻水含量。荧光光谱结果表明橙皮素对肌球蛋白的猝灭过程包括动态猝灭和静态猝灭,它主要通过疏水相互作用与肌球蛋白结合；二氢槲皮素和芒果苷对肌球蛋白的猝灭是静态猝灭，它们主要通过氢键和范德华力与肌球蛋白结合；所有这三种多酚在肌球蛋白上只有一个结合位点。表面疏水性表明所有四种多酚都参与与肌球蛋白的非共价结合(疏水相互作用)。红外光谱表明，这四种多酚的添加显着增加了肌球蛋白的α-螺旋含量。他们还减少了肌球蛋白的颗粒大小，zeta电位,和蛋白质变性程度。扫描电子显微镜显示，四种多酚降低了聚集度，而肌球蛋白颗粒分布更均匀。这些观察结果为多酚的筛选和进一步研究多酚对冷冻肌球蛋白的保护机制提供了依据。
