酪蛋白-葡萄糖-PGG纳米复合物的制备及其延缓线虫衰老能力的研究

本文采用凝胶电泳、红外光谱和荧光光谱研究酪蛋白与葡萄糖美拉德接枝物的相互作用方式，接着用溶剂蒸发法制备酪蛋白-葡萄糖-PGG（1,2,3,4,6-O-五没食子酰葡萄糖）纳米复合物，以期提高PGG的水溶性及延缓秀丽隐杆线虫衰老能力。结果表明，生成的接枝物分子量大于116 ku。糖末端的羰基与蛋白的氨基以化学共价键相连，酪蛋白中引入的糖分子具有D-吡喃葡萄糖环结构。PGG与酪蛋白或酪蛋白-葡萄糖作用力主要为疏水力。PGG与酪蛋白-葡萄糖接枝共聚物在疏水力诱导下协同组装得到酪蛋白-葡萄糖-PGG纳米复合物，纳米粒子包埋率为62.27%，粒径为265 nm。该纳米粒子外观呈淡黄色。当浓度为10 mg/mL时，该纳米粒子在水中溶解度较好。酪蛋白-葡萄糖-PGG纳米复合物组线虫平均寿命比PGG组延长了13.00%，因此酪蛋白-葡萄糖接枝共聚物的包埋能有效增强PGG的延缓线虫衰老能力。
A casein and glucose copolymer was prepared by Maillard reaction and its properties investigated by gel electrophoresis, Fourier transform infrared spectroscopy, and fluorescence spectroscopy. Casein-g-glucose-PGG nanocomplexes were prepared using the solvent evaporation method to improve the water solubility and anti-aging effects of PGG in Caenorhabditis elegans. The results showed that the molecular weight of the conjugate product (casein-g-glucose) was larger than 11 ku. The reducing end of the glucose was covalently linked with the amino group of the protein, and the sugar molecule introduced into the casein had a d-glucopyranose ring structure. The binding force between PGG and casein, or casein-g-glucose, was mainly hydrophobic interaction, which induced the self-assembly of PGG and casein-g-glucose to form casein-g-glucose-PGG nanocomplexes. The encapsulation efficiency of the nanocomplex reached up to 62.27%, the particle size of the nanocomplexes was 265 nm, and the nanocomplexes were light-yellow powders. Nanocomplexes showed good solubility in water at a concentration of 10 mg / mL. Compared with PGG treatment, treatment with the nanocomplexes could significantly extend the mean worm lifespan by 13.00%. In conclusion, the nanocomplex can effectively increase the anti-aging effect of PGG in C. elegans.