Abstract:

The novel protein-polysaccharide nanogels were fabricated through a combination of Maillard reaction and self-assembly method, which is facile, safe and green. First, amphiphilic soy β-conglycinin-dextran conjugates (SDC) were prepared by grafting dextran onto soy β-conglycinin via Maillard dry-heating reaction. Then, a heat treatment above the denaturation temperature of protein was used to form soy β-conglycinin-dextran nanogels (SDN). The morphology observation indicated that SDN were of spherical shape with core-shell structures, and the zeta-potential study further verified that soy β-conglycinin was covered with nonionic dextran. The surface hydrophobicity investigation displayed that the conformation of protein was changed and the hydrophobic groups of soy β-conglycinin were exposed to the surface of protein. Therefore, several hydrophobic compartments were formed in the core. The nanogels were pretty stable against long-term storage and pH change. These valuable properties and the low toxicity of nanogels may provide a promising way to deliver hydrophobic compounds.

Key words: soy β-conglycinin, dextran, Maillard reaction, self-assembly, core-shell structure, nanogels

摘要：

基于蛋白质与多糖的Maillard反应与自组装制备一种新型的绿色的具备核壳结构的纳米凝胶。利用干热反应制备大豆7S球蛋白与葡聚糖的共价接枝物（soy β-conglycinin-dextran conjugates，SDC），通过对SDC热处理使其自组装成大豆7S球蛋白-葡聚糖纳米凝胶（soy β-conglycinin-dextran nanogels，SDN），对其形貌、结构及性质进行分析，并利用多糖的空间位阻效应抑制蛋白质宏观过度聚集的理论指导，探讨尺寸均一SDN的形成机制。形貌学与zeta电位分析表明SDN为具备核壳结构的球状粒子，其外壳由亲水性的葡聚糖构成，内核由凝胶化的蛋白构成；表面疏水性分析表明内核蛋白的三级结构发生转变，疏水基团暴露，从而形成多个疏水空腔；稳定性分析表明SDN具有高度的pH稳定性与储存稳定性，对疏水活性物质的输送载体构建具有重要的借鉴意义。

关键词: 大豆7S球蛋白, 葡聚糖, Maillard反应, 自组装, 核壳结构, 纳米凝胶