Multiscale coupling of mesoscopic- and atomistic-level lipid bilayer simulations
Multiscale coupling of mesoscopic- and atomistic-level lipid bilayer simulations
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DOI：
10.1063/1.1931651
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发表时间：
2005-06-22
影响因子：
4.4
通讯作者：
Voth, GA
中科院分区：
文献类型：
--
作者：
Chang, R;Ayton, GS;Voth, GA
本文提出了一种多尺度方法来连接原子膜系统和介观膜系统。在这种情况下的原子模型是联合原子二肉豆蔻酰磷脂酰胆碱膜系统，虽然该方法是完全通用的。原子分子动力学提供了用于参数化介观弹性膜模型的膨胀模量。所得到的弹性膜模型，包括明确的介观溶剂，显示出适当的静态和动态波动行为。然后可以使用介观膜系统容易地模拟类似于100 nm长度的大膜。从介观系统回到原子尺度系统的临界反馈是通过将介观膜中的小区域的应力（或表面张力）桥接到相应的原子膜系统来实现的。由于膜的长尺度模式，如波动和屈曲，当受到外部扰动时，局部张力的响应不同于框架张力。这些膜模式的效果示出的局部膜区域的应力响应，因此原子膜系统。此外，独立和多尺度耦合系统的某些平衡静态和动态特性，提出了几种不同的膜尺寸。虽然静态属性，如二维对相关函数和顺序参数显示没有显着的差异为不同的系统，脂质的自扩散和脂质偶极子的旋转松弛有很强的依赖于膜的大小（或长波长的膜运动），这是正确的建模本多尺度方法。(c)2005年美国物理学会。
A multiscale method is presented to bridge between the atomistic and mesoscopic membrane systems. The atomistic model in this case is the united atom dimyristoylphosphatidylcholine membrane system, although the method is completely general. Atomistic molecular dynamics provides the expansion modulus which is used to parametrize a mesoscopic elastic membrane model. The resulting elastic membrane model, including explicit mesoscopic solvent, shows appropriate static and dynamic undulation behaviors. Large membranes of similar to 100 nm in length can then be easily simulated using the mesoscopic membrane system. The critical feedback from the mesoscopic system back down to the atomistic-scale system is accomplished by bridging the stress (or surface tension) of a small region in the mesoscopic membrane to the corresponding atomistic membrane system. Because of long length-scale modes of membranes such as undulation and buckling, the local tension responds differently from the frame tension, when subjected to external perturbations. The effect of these membrane modes is shown for the stress response of a local membrane region and therefore the atomistic membrane system. In addition, certain equilibrium static and dynamic properties of stand-alone and multiscale coupled systems are presented for several different membrane sizes. Although static properties such as two-dimensional pair-correlation function and order parameters show no noticeable discrepancy for the different systems, lipid self-diffusion and the rotational relaxation of lipid dipoles have a strong dependence on the membrane size (or long-wavelength membrane motions), which is properly modeled by the present multiscale method. (c) 2005 American Institute of Physics.