Cai Yaqian, Zhao Hanying
Key Laboratory of Functional Polymer Materials, Ministry of Education, College of Chemistry, Nankai University, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300071, China.
ACS Appl Bio Mater. 2019 Jan 22;2(1):470-479. doi: 10.1021/acsabm.8b00672. Epub 2018 Dec 31.
Studies on protein adsorption on nanoparticles have attracted great interest over the past years due to the unique properties of the protein-immobilized nanoparticles. However, the effects of protein adsorption on the stability of nanoparticles and the role of hydrophobic interaction in the adsorption have not been fully understood. Herein, fundamental research on protein-induced dissociation of biomolecular assemblies based on hydrophobic interaction is reported. Bovine serum albumin (BSA) is used as a model protein, and cholesterol-glutathione bioconjugate (Ch-GSH) and cholesterol-terminated polyethylene glycol (Ch-PEG) are chosen as model amphiphilic biomolecules. Ch-GSH or Ch-PEG molecules are able to self-assemble into vesicles. The walls and the coronae of the assemblies are composed of hydrophobic Ch and hydrophilic GSH (or PEG), respectively. Upon addition of BSA into phosphate buffer saline solutions of the assemblies, vesicle structures are dissociated and small-sized aggregates composed of BSA, and amphiphilic biomolecules are formed. The dissociation temperatures of the vesicles can be determined by dynamic light scattering. Transmission electron microscopy and size exclusion chromatography are used to demonstrate the dissociation of the assemblies and the formation of aggregates. The hydrophobic interaction between hydrophobic patches on BSA molecules and Ch groups in the walls of the assemblies is responsible for the dissociation of the vesicles and the formation of the aggregates with smaller sizes.
在过去几年中，由于蛋白质固定化纳米颗粒的独特性质，关于蛋白质在纳米颗粒上的吸附研究引起了极大的关注。然而，蛋白质吸附对纳米颗粒稳定性的影响以及疏水相互作用在吸附中的作用尚未得到充分理解。在此，报道了基于疏水相互作用的蛋白质诱导生物分子组装体解离的基础研究。牛血清白蛋白（BSA）用作模型蛋白质，胆固醇-谷胱甘肽生物共轭物（Ch-GSH）和胆固醇末端聚乙二醇（Ch-PEG）被选为模型两亲生物分子。Ch-GSH或Ch-PEG分子能够自组装成囊泡。组装体的壁和冠分别由疏水性的Ch和亲水性的GSH（或PEG）组成。将BSA添加到组装体的磷酸盐缓冲盐溶液中后，囊泡结构解离，形成由BSA和两亲生物分子组成的小尺寸聚集体。囊泡的解离温度可以通过动态光散射测定。透射电子显微镜和尺寸排阻色谱用于证明组装体的解离和聚集体的形成。BSA分子上的疏水区域与组装体壁中的Ch基团之间的疏水相互作用导致了囊泡的解离和较小尺寸聚集体的形成。
