基于单电荷液滴微流控技术的生物大分子结晶行为的研究

The high-resolution determination of the tertiary structures of protein molecules not only provides us better understanding of their biological functions and molecular interactions, but also plays important roles in the fields of life science, drug screening, decease diagnostics and therapy. To date, obtaining high quality crystal structures of protein remains one of the bottle-necks. To obtain the crystallization conditions, large scale screening is typically required, and thus the consumption of proteins and time increase dramatically. In the proposal, we aim to set up a singly charged droplet microfluidic system, and to investigate its application in the fabrication of singly charged droplets containing protein, precipitants, and other additives, for the investigation of the crystallization behavior of protein molecules. By tuning the sign and amount of charges on the surface of droplets, the absorption of the protein molecules on the surface can be regulated for the screening crystallization conditions of proteins. Finally, we investigate the volume effects on the protein crystallizing process and the electric field induced accumulation, nucleation, and crystallization behavior of protein molecules within the charged droplets. This research should find many potential applications in the fields of crystallization and phase transition of proteins, other biological macromolecules and synthetic polymers.

蛋白质分子三级结构的精确解析不仅可以帮助人们更好地理解其功能和分子间相互作用，对相关生命科学、医药筛选、疾病诊断和治疗等领域还具有重要的意义。目前，蛋白质的三级结构的解析主要依赖高质量晶体的X射线衍射实验。由于因素复杂且无法预测，结晶条件的筛选实验需要耗费大量的蛋白质样品和时间成本。本项目拟通过设计和搭建可产生单电荷液滴的微流控技术平台，研究制备一系列包含蛋白质、沉淀剂和其他添加剂的表面带单电荷的混合液滴，进行蛋白质分子结晶的研究。研究通过改变液滴表面的电荷种类以及电量大小，对蛋白质分子在液滴表面的吸附进行调控和结晶条件的筛选。最后，研究蛋白质结晶液滴在结晶过程中的体积效应问题，并探索电场诱导的蛋白质分子在单电荷液滴里面的富集、成核以及结晶行为。该研究的预期成果有望为蛋白质、其他生物材料、合成聚合物等大分子在溶液中的结晶或者其他相转变行为的研究提供技术平台和奠定一定的理论基础。