蛋白质分子在聚电解质刷子中负载机理的研究

It is found in experiments that, when the solution PH value is higher than the isoelectric point value, protein molecules with net negative charges can be adsorbed inside weak-acid type polyelectrolyte brushes in large amount. The driving force for such adsorption phenomenon is currently under debate. This project intends to apply the continuum self-consistent field theory to the numerical study of the uptake of proteins inside polyelectrolyte brushes, with the aim of unraveling the mechanism governing the adsorption of net negatively charged proteins inside negatively charged polyelectrolyte brushes. In this study, the influences of the surface charge patchness of proteins, the entropic effect of counter-ions, the electrostatic interaction, the elastic effect of polymer chains, the solution PH and added salt ions on the uptake of proteins inside polyelectrolyte brushes will be examined, and the governing mechanism is elucidated, thus laying a solid foundation for the experimental design and fabrication of highly efficient polyelectrolyte brushes for the uptake of protein molecules.

实验发现在溶液PH值大于等电点值条件下，带净负电的蛋白质分子依然能够在带负电的弱酸型聚电解质刷子中以很高的量吸附负载，此吸附现象的驱动力目前在理论上有很大的争议。本项目拟运用连续相高分子自冾场理论通过数值求解自冾方程组研究蛋白质分子在聚电解质刷子中吸附负载，确定其吸附负载机制以便澄清目前的学术争论，阐明蛋白质分子表面正/负电荷空间缀块性、反离子的熵效应、静电作用、高分子链弹性、溶液PH值和外加盐离子浓度这几大因素对蛋白质分子在聚电解质刷子中吸附负载的影响机理，为实验设计和制备高效率的负载蛋白质分子的聚电解质刷子奠定较为坚实的理论基础。

我们按照自然科学基金任务书的要求,并将研究内容稍微进行了调整, 运用连续相带电高分子自洽场理论数值计算和朗之万分子动力学方法模拟研究聚电解质刷子的构象行为和其对外界刺激的响应。我们对强酸/强碱型和弱酸/弱碱型高分子刷子对外加电场的响应,以及自由末端单体带电的高分子刷对外加电场的响应进行了系统的研究。定量分析了高分子链弹性、静电作用、反离子熵效应、溶液pH值、外加电场以及高电价态带电末端单体等因素对高分子链构象、单体和反离子分布、电极板附近电荷平衡、刷子高度标度率等的影响并揭示其影响规律，阐明了外界刺激对弱酸/弱碱型刷子中高分子链带电官能团酸-碱电离平衡的作用机理,并对含高电价态末端单体高分子刷子体系中的电荷浓度涨落、强相关联效应进行了较为深入的探讨。本项目比较好的完成了基金项目的任务目标, 为实验设计和制备优良的对外界刺激响应的聚电解质刷子奠定较为坚实的理论基础。本项目研究也是试图解决聚电解质理论这一重大且悬而未决的高分子物理问题的一个很小的尝试。