Pan Xiaoyun, Mu Minfang, Hu Bin, Yao Ping, Jiang Ming
Department of Macromolecular Science and the Key Laboratory of Molecular Engineering of Polymer, Fudan University, Shanghai, China.
Biopolymers. 2006 Jan;81(1):29-38. doi: 10.1002/bip.20372.
Casein is almost insoluble at around pH 4.6, which is its isoelectric point (pI). Grafting copolymer, casein-g-dextran, was prepared through the Amadori rearrangement of the Maillard reaction. The copolymer has a reversible pH sensitive property: micellization at the pI of casein forming a casein core and dextran shell structure and dissociation when pH differs from the pI. The micelles produced at pH 4.6 have a spherical shape and their size is dependent on the Maillard reaction: reaction time, molar ratio of casein to dextran, and molecular weight of dextran used. Typically, the hydrodynamic diameter of the micelles is about 100 nm and the critical micelle concentration is about 10 mg/L. The micelles are very stable in aqueous solution and can be stored as lyophiled powder. The micelles are able to encapsulate hydrophobic compounds such as pyrene.
酪蛋白在其等电点（pI）约为pH 4.6时几乎不溶。通过美拉德反应的阿马多里重排制备了接枝共聚物酪蛋白-g-葡聚糖。该共聚物具有可逆的pH敏感特性：在酪蛋白的pI处发生胶束化，形成酪蛋白核心和葡聚糖外壳结构，当pH值与pI不同时会解离。在pH 4.6时产生的胶束呈球形，其尺寸取决于美拉德反应：反应时间、酪蛋白与葡聚糖的摩尔比以及所用葡聚糖的分子量。通常，胶束的流体动力学直径约为100 nm，临界胶束浓度约为10 mg/L。这些胶束在水溶液中非常稳定，可以冻干粉末形式储存。这些胶束能够包封芘等疏水性化合物。
