Duan Hua, Li Jianfeng, Zhang Hongdong, Qiu Feng, Yang Yuliang
The State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai, 200433, China.
J Biol Phys. 2018 Mar;44(1):1-16. doi: 10.1007/s10867-017-9471-6. Epub 2017 Oct 10.
Endocytotic and exocytotic processes are usually studied using particle-vesicle systems in theory, but most of them are electroneutral. Nevertheless, charged particle-vesicle systems are much closer to real biological systems. Therefore, wrapping behaviors of a negatively charged vesicle wrapping a positively charged particle are systematically investigated by a series of 2D dynamical simulations in this article. The competition between the elastic bending energy and the electrostatic energy dictates the vesicle configuration and charge distribution. It is found that only for intermediate charge concentrations and small particle sizes a vesicle can completely engulf the particle. When the charge density is high, the interaction between vesicle and particle is unexpectedly weakened by both the hardening effect of the charged membrane and the effective-transportation-frozen effect of the charged components. When the particle is strongly charged, multi-layer folding conformations are observed. These studies may provide important insights into mechanism of endocytotic and exocytotic processes in biological systems.
理论上，内吞和外排过程通常使用颗粒 - 囊泡系统进行研究，但其中大多数是电中性的。然而，带电颗粒 - 囊泡系统更接近真实的生物系统。因此，本文通过一系列二维动力学模拟系统地研究了带负电的囊泡包裹带正电颗粒的包裹行为。弹性弯曲能和静电能之间的竞争决定了囊泡的形态和电荷分布。研究发现，只有在中等电荷浓度和小颗粒尺寸的情况下，囊泡才能完全吞噬颗粒。当电荷密度较高时，带电膜的硬化效应和带电成分的有效运输冻结效应都会意外地削弱囊泡与颗粒之间的相互作用。当颗粒带强电荷时，会观察到多层折叠构象。这些研究可能为生物系统中内吞和外排过程的机制提供重要见解。
