On the Importance of Hydrodynamic Interactions in Lipid Membrane Formation
On the Importance of Hydrodynamic Interactions in Lipid Membrane Formation
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DOI：
10.1016/j.bpj.2012.11.3829
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发表时间：
2013-01-08
影响因子：
3.4
通讯作者：
Skolnick, Jeffrey
中科院分区：
文献类型：
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作者：
Ando, Tadashi;Skolnick, Jeffrey
流体动力相互作用(HI)引起分子间的集体运动，这在无规卷曲聚合物和胶体的动力学中是重要的。然而，它们在许多分子系统的生物自组装中的作用还没有被研究。在这里，我们使用布朗动力学模拟，评估HI在脂膜自组装动力学中的重要性。周期模拟盒中的1000个粗粒脂质分子在分子间HI的存在和不存在的情况下被允许组装成稳定的双层。流体动力相互作用使单体-单体缔合率降低50%。相反，在分子间HI存在的情况下，脂簇的缔合速度要快得多。事实上，有分子间HI时，膜的自组装速度比没有分子间HI时快3-10倍。我们引入了一个解析模型来描述粒子团簇的扩散相遇速率对尺寸的依赖关系，该模型可以定性地解释我们对膜自组装过程早期阶段的模拟结果。这些结果清楚地表明，HI对自组装动力学有很大的影响，没有HI的模拟将大大低估这种过程的动力学参数。
Hydrodynamic interactions (HI) give rise to collective motions between molecules, which are known to be important in the dynamics of random coil polymers and colloids. However, their role in the biological self-assembly of many molecule systems has not been investigated. Here, using Brownian dynamics simulations, we evaluate the importance of HI on the kinetics of self-assembly of lipid membranes. One-thousand coarse-grained lipid molecules in periodic simulation boxes were allowed to assemble into stable bilayers in the presence and absence of intermolecular HI. Hydrodynamic interactions reduce the monomer-monomer association rate by 50%. In contrast, the rate of association of lipid clusters is much faster in the presence of intermolecular HI. In fact, with intermolecular HI, the membrane self-assembly rate is 3-10 times faster than that without intermolecular HI. We introduce an analytical model to describe the size dependence of the diffusive encounter rate of particle clusters, which can qualitatively explain our simulation results for the early stage of the membrane self-assembly process. These results clearly suggest that HI greatly affects the kinetics of self-assembly and that simulations without HI will significantly underestimate the kinetic parameters of such processes.