Yang Wei, Liu Fuguo, Xu Chenqi, Sun Cuixia, Yuan Fang, Gao Yanxiang
J Agric Food Chem. 2015 May 27;63(20):5035-45. doi: 10.1021/acs.jafc.5b01881. Epub 2015 May 13.
The aggregation of lactoferrin and (-)-epigallocatechin gallate (EGCG) was inhibited by polyphenols, oligosaccharides, and collagen peptide in this study. Polyphenols, oligosaccharides, or collagen peptide can effectively prevent the formation of lactoferrin-EGCG aggregates, respectively. The addition sequence of lactoferrin, polyphenols (oligosaccharides or collagen peptide) and EGCG can affect the turbidity and particle size of the ternary complexes in the buffer solution; however, it hardly affected the ζ-potential and fluorescence characteristics. With either positive or negative charge, polyphenols and collagen peptide disrupted the formation of lactoferrin-EGCG aggregate mainly through the mechanism of its competition with EGCG molecules which surrounded the lactoferrin molecule surface with weaker binding affinities, forming polyphenols or a collagen peptide-lactoferrin-EGCG ternary complex; for neutral oligosaccharides, the ternary complex was generated mainly through steric effects, accompanied by a change in the lactoferrin secondary structure induced by gallic acid, chlorogenic acid, and xylo-oligosaccharide. Polyphenols, oligosaccharides, or collagen peptide restraining the formation of lactoferrin-EGCG aggregate could be applied in the design of clear products in the food, pharmaceutical, and cosmetic industries.
本研究中，乳铁蛋白与（-）-表没食子儿茶素没食子酸酯（EGCG）的聚集受到多酚、低聚糖和胶原肽的抑制。多酚、低聚糖或胶原肽可分别有效防止乳铁蛋白-EGCG聚集体的形成。乳铁蛋白、多酚（低聚糖或胶原肽）和EGCG的添加顺序会影响缓冲溶液中三元复合物的浊度和粒径；然而，这几乎不影响ζ电位和荧光特性。无论带正电荷还是负电荷，多酚和胶原肽主要通过与EGCG分子竞争的机制破坏乳铁蛋白-EGCG聚集体的形成，EGCG分子以较弱的结合亲和力围绕在乳铁蛋白分子表面，形成多酚或胶原肽-乳铁蛋白-EGCG三元复合物；对于中性低聚糖，三元复合物主要通过空间位阻效应产生，同时伴随着没食子酸、绿原酸和木寡糖诱导的乳铁蛋白二级结构变化。抑制乳铁蛋白-EGCG聚集体形成的多酚、低聚糖或胶原肽可应用于食品、制药和化妆品行业澄清产品的设计中。
