基于液滴微流控技术的蛋白质结晶

Protein crystallization research based on droplet microfluidics

结晶是培养蛋白质单晶以及蛋白质分离纯化的一种重要手段。传统静态蛋白质结晶操作周期长,晶体粒径分布不均。液滴微流控技术能够实现低雷诺数条件下的高效传质传热,是提高蛋白质结晶速率以及改善晶体尺寸分布的潜在方法。本研究利用液滴微流控系统分别在静止液滴和低剪切速率(流动液滴)条件下进行蛋白质结晶。实验结果表明,微流控液滴内循环可以有效提高成核速率和晶体数量,并且成核速率、平均晶体数量和晶体尺寸均与液滴流速呈单调依赖关系,证明了微流控液滴内温和的剪切力场是改善蛋白质晶粒度分布,减少蛋白质晶体聚集的有效手段。此外,活性实验表明微液滴内循环对溶菌酶的活性并未产生明显影响。

Crystallization is an important tool for the cultivation of protein single crystals as well as protein separation and purification.Conventional static protein crystallization has problems such as long operation cycle and uneven crystal size distribution.Droplet microfluidics is a potential method to increase protein crystallization rate and improve crystal size distribution because of its low reagent consumption and high efficiency of mass and heat transfer under low Reynolds number conditions.This study investigated lysozyme crystallization using a droplet microfluidic system under static droplet and low shear rate(flowing droplet)conditions,respectively.The experimental results showed that the microfluidic droplet internal circulation could effectively improve the nucleation rate and crystal number.Furthermore,nucleation rate,average crystal number and crystal size were monotonically dependent on the oscillation flow rate.In addition,the activity experiments showed that the forced circulation of microdroplets did not have a significant effect on the lysozyme activity.