Department of Informatics, Faculty of Science, J. E. Purkinje University, Ústí n. Lab., Czech Republic.
Laboratory of Aerosols Chemistry and Physics, Institute of Chemical Process Fundamentals of the CAS, v. v. i., Prague, Czech Republic and Department of Physics, Faculty of Science, J. E. Purkinje University, Ústí n. Lab., Czech Republic.
Soft Matter. 2017 Feb 22;13(8):1634-1645. doi: 10.1039/c6sm02751b.
We use a meso-scale dissipative particle dynamics method to simulate the flow and aggregation of rod-like protein solutions through pores grafted with a solvent-sensitive polymer brush. The coated pores can control protein permeability and aggregation by a stretch-to-collapse conformational transition of the brush polymers in response to changes in the solvent quality. The protein solutions mimic aqueous glycoprotein solutions and proteins are represented as rod-like objects formed by coarse-grain beads. The model further employs two types of beads to represent the existence of cystein-like terminal groups in real glycoproteins and mimic the aggregation of real glycoproteins in aqueous solutions. We vary the solvent quality with respect to the brush chains and study the flow and aggregation of rod-like proteins in the slit and cylindrical pores as the brush polymers undergo the stretch-to-collapse transition. The results show that stretched brush chains close the pore, hamper proteins' flow and promote proteins' aggregation. The collapsed brush chains open the pores for proteins' flow and suppress their aggregation. Therefore, we observe more than a ten-fold reduction in the permeation rate of proteins in both pore geometries. Finally, due to pore confinement, larger proteins' aggregates are formed in the slit pore than in the cylindrical pore, while more pronounced orientation of proteins in the flow direction is seen in the cylindrical pore than in the slit pore.
我们使用介观耗散粒子动力学方法模拟了通过接枝溶剂敏感聚合物刷的孔中棒状蛋白溶液的流动和聚集。涂层孔可以通过刷聚合物在溶剂质量变化时的拉伸-坍塌构象转变来控制蛋白质的渗透性和聚集。蛋白溶液模拟了水性糖蛋白溶液，蛋白被表示为由粗粒珠形成的棒状物体。该模型进一步采用两种类型的珠粒来代表真实糖蛋白中半胱氨酸末端基团的存在，并模拟真实糖蛋白在水溶液中的聚集。我们改变了相对于刷链的溶剂质量，并研究了在刷聚合物经历拉伸-坍塌转变时，棒状蛋白在狭缝和圆柱孔中的流动和聚集。结果表明，拉伸的刷链关闭了孔，阻碍了蛋白质的流动并促进了蛋白质的聚集。而坍塌的刷链则打开了孔，使蛋白质能够流动，并抑制了它们的聚集。因此，我们观察到两种孔几何形状中蛋白质的渗透速率都降低了十倍以上。最后，由于孔的限制，在狭缝孔中形成的较大蛋白质聚集体比在圆柱孔中多，而在圆柱孔中，蛋白质在流动方向上的取向更为明显。
