Transport phenomena in fluid films with curvature elasticity
Transport phenomena in fluid films with curvature elasticity
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具有曲率弹性的流体膜中的输运现象
DOI：
10.1017/jfm.2020.711
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发表时间：
2020
影响因子：
3.7
通讯作者：
Rangamani, Padmini
中科院分区：
文献类型：
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作者：
Mahapatra, Arijit;Saintillan, David;Rangamani, Padmini
细胞膜是含有多种蛋白质的弹性脂双层，包括离子通道、受体和支架蛋白。众所周知，这些蛋白质扩散在膜的平面上，并影响膜的弯曲。实验表明，膜平面内的脂质流动与蛋白质的扩散是紧密耦合的。因此，需要有一个全面的框架，说明这些进程之间的相互作用。在这里，我们提出了一个关于脂类的面内粘性流动、跨膜蛋白的扩散和脂类双层的弹性变形的理论。膜中的蛋白质被模拟为通过诱导自发弯曲来影响膜的弯曲。我们用修正的Helfrich曲率弹性能密度函数来表示膜的自由能，以考虑蛋白质的化学势能。我们推导了该系统的守恒定律和运动方程。最后，我们给出了量纲分析和数值模拟的结果，并演示了耦合输运过程在控制膜弯曲和蛋白质扩散动力学中的作用。
Cellular membranes are elastic lipid bilayers that contain a variety of proteins, including ion channels, receptors and scaffolding proteins. These proteins are known to diffuse in the plane of the membrane and to influence the bending of the membrane. Experiments have shown that lipid flow in the plane of the membrane is closely coupled with the diffusion of proteins. Thus, there is a need for a comprehensive framework that accounts for the interplay between these processes. Here, we present a theory for the coupled in-plane viscous flow of lipids, diffusion of transmembrane proteins and elastic deformation of lipid bilayers. The proteins in the membrane are modelled such that they influence membrane bending by inducing a spontaneous curvature. We formulate the free energy of the membrane with a Helfrich-like curvature elastic energy density function modified to account for the chemical potential energy of proteins. We derive the conservation laws and equations of motion for this system. Finally, we present results from dimensional analysis and numerical simulations and demonstrate the effect of coupled transport processes in governing the dynamics of membrane bending and protein diffusion.