Stabilizing Leaflet Asymmetry under Differential Stress in a Highly Coarse-Grained Lipid Membrane Model
Stabilizing Leaflet Asymmetry under Differential Stress in a Highly Coarse-Grained Lipid Membrane Model
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DOI：
10.1021/acs.jctc.0c00862
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发表时间：
2020-11-10
影响因子：
5.5
通讯作者：
Deserno, Markus
中科院分区：
文献类型：
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作者：
Foley, Samuel;Deserno, Markus
我们提出了一个版本的粗粒度库克脂质模型，修改模拟不对称的脂质膜。它的灵感来自于Wang等人[Commun. Comput. 2013，13，1093-1106]，但更稳健地应对差异应力，代价是每个脂质一个额外的珠粒以及伴随的计算开销增加。双层的不对称性最终打破了系统尺寸依赖的临界差应力，这可以从一个简单的分析模型预测。我们重新测量了新模型的许多重要材料参数，发现它与典型的流体脂质膜一致。保持一个稳定的应力不对称性有许多应用，我们给出了两个例子：（i）连接单层应力脂质数不对称，以直接测量单层面积模量和（ii）通过监测平衡双层面积找到其应变相关的高阶校正。
We present a version of the coarse-grained Cooke lipid model, modified to simulate asymmetric lipid membranes. It is inspired by a method employed by Wang et al. [Commun. Comput. Phys. 2013, 13, 1093-1106] for artificially penalizing lipid flip-flop but copes more robustly with differential stress, at the cost of one additional bead per lipid and the concomitant increase in computational overhead. Bilayer asymmetry ultimately breaks down beyond a system size dependent critical differential stress, which can be predicted from a simple analytical model. We remeasure many important material parameters for the new model and find it to be consistent with typical fluid lipid membranes. Maintaining a stable stress asymmetry has many applications, and we give two examples: (i) connecting monolayer stress to lipid number asymmetry in order to directly measure the monolayer area modulus and (ii) finding its strain-dependent higher-order correction by monitoring the equilibrium bilayer area.