作者：Yuanyuan Han, Jie Cui, Jing Jin, Wei Jiang
关键字：蛋白质吸附, 聚合物刷, 氢键, Monte Carlo模拟, 接枝密度, 溶菌酶
论文来源：期刊
具体来源：Journal of Materials Chemistry B, 2017, 5(43), 8479-8486
发表时间：2017年

摘要：采用Monte Carlo模拟研究了蛋白质与聚合物刷之间存在氢键作用时的蛋白质吸附行为。模拟中观察到有趣的现象：蛋白质吸附量随接枝密度变化出现最小值，即存在具有最小蛋白质吸附量的临界接枝密度。临界接枝密度的存在揭示了蛋白质吸附的两种不同驱动力：当接枝密度高于临界值时，蛋白质吸附驱动力主要是蛋白质与聚合物刷之间的氢键；当接枝密度低于临界值时，驱动力是蛋白质与疏水基底之间的吸引。值得注意的是，在临界接枝密度下，提高聚合物刷的亲水性反而导致蛋白质吸附量增加，即使聚合物刷亲水性提高会抑制蛋白质与聚合物刷之间氢键的形成，这主要源于聚合物链从塌缩到伸展的构象转变。研究表明，蛋白质吸附与接枝密度的关系与此前的实验工作高度一致；模拟结果还提供了蛋白质吸附位置和接枝链构象的详细信息，有助于更好地理解氢键诱导的聚合物刷蛋白质吸附行为。

Abstract：Using Monte Carlo simulation, we investigate the protein adsorption behaviors on polymer brushes in the presence of hydrogen bonding between proteins and polymer brushes. It is interesting to observe in simulation that as a function of grafting density, the protein adsorbed amount passes through a minimum, that is, a critical grafting density with minimum protein adsorbed amount exists. The existence of a critical grafting density uncovers two different driving forces of protein adsorption. The driving force of protein adsorption is mainly the hydrogen bonding between proteins and polymer brushes when the grafting density is above the critical value, whereas the driving force is the attractions between proteins and the hydrophobic substrate when the grafting density is below the critical value. It is extraordinary that at the critical grafting density, the increasing hydrophilicity of polymer brush will lead to an increase of protein adsorption, even when the formation of hydrogen bonding between proteins and polymer brushes is suppressed by the increasing hydrophilicity of polymer brushes. This mainly results from the conformational transition of the polymer chains from collapse to stretch when the hydrophilicity is increased. The relationship between protein adsorption and grafting density reported in this study is quite consistent with our previous experimental work, and the simulation results also provide detailed information about protein adsorption location and grafting chain conformation.

论文链接：https://doi.org/10.1039/c7tb02465g