【作者】 吴宛容； 邵彦春； 吕优优；

【Author】 Wu Wanrong;Shao Yanchun;Lv Youyou;College of Food science and Technology,Huazhong Agricultural University;Key Laboratory of Enviroment Correlative Dietology,Ministry of Education,Huazhong Agricultural University;

【机构】 华中农业大学食品科学技术学院； 华中农业大学环境食品学教育部重点实验室；

【摘要】 目的:乳铁蛋白(Lactoferrin,LF)是哺乳动物免疫系统中的重要组分,具有多种重要的生理功能。然而,人源LF(hLF)价格昂贵,牛源LF(bLF)含量低,限制了其广泛的应用。植物源重组hLF的出现为LF的应用提供了新的方向。方法:本研究以bLF为参照,探究四种典型食物多酚(绿茶多酚表没食子儿茶素没食子酸酯(Gallocatechin gallate,EGCG)、奎宁酸(Quinic acid,QA)、咖啡酸(Caffeic acid,CA)和阿魏酸(Ferulic acid,FA))分别与水稻重组人乳铁蛋白(OsrhLF)制备共价复合物,并对其结构和理化特性差异进行了深入研究。结果与讨论:通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)确定了LF-多酚共价物的形成。多种光谱方法(CD、FTIR、荧光)、粒径电位以及SEM微观形态结果表明,多酚共价修饰改变了两种不同来源的LF的二、三级结构,使LF在水溶液中分散更加均匀和稳定,在一定程度上抑制了LF的聚集。此外,共价多酚显著增加了两种LF的表面亲水性,提高了其热稳定性和抗氧化活性,而相对于bLF,OsrhLF在水溶液中更加亲水且多酚改善OsrhLF的热稳定性效果要强于bLF。综上,植物源重组hLF在大量赋存多酚的物料中状态较为稳定,且其共价结合多酚可显著改善蛋白特性,为植物源重组hLF在食品中的应用提供了理论依据。更多还原

【Abstract】 Purpose:Lactoferrin(LF) is an important component of mammalian immune system,which has many important physiological functions.However,the high price of human derived LF(hLF) and the low content of bovine derived LF(bLF)limit its widespread application.The emergence of plant-based recombinant hLF provides a new direction for the application of LF.Method:With bLF as a reference,this study explored the preparation of covalent complexes of four typical food polyphenols(green tea polyphenol Epigallocatechin gallate(EGCG),Quinic acid(QA),Caffeic acid(CA) and Ferulic acid(FA)) with rice recombinant human lactoferrin(OsrhLF),respectively,and conducted in-depth research on their differences in structure and physicochemical properties.Results and Discussion:The formation of LF-polyphenol covalent was determined by Sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE).Multiple spectral methods(CD,FTIR,fluorescence),particle size potential,and SEM microscopic morphology results indicated that the covalent modification of polyphenols altered the secondary and tertiary structures of two different sources of LF,led LF more uniformly and stably dispersed in aqueous solution,and to some extent inhibited LF aggregation.In addition,covalent polyphenols significantly increased the surface hydrophilicity of two types of LFs,improved their thermal stability and antioxidant activity.Compared to bLF,OsrhLF was more hydrophilic in aqueous solution and polyphenols had a stronger effect on improving the thermal stability of OsrhLF than bLF.In summary,plant-based recombinant hLF had a relatively stable state in materials containing a large number of polyphenols,and its covalent binding with polyphenols could significantly improve protein properties,providing a theoretical basis for the application of plant-based recombinant hLF in food.更多还原