Vesicle deformation and division induced by flip-flops of lipid molecules
Vesicle deformation and division induced by flip-flops of lipid molecules
复制标题
脂质分子触发器诱导的囊泡变形和分裂
DOI：
10.1039/d1sm00847a
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发表时间：
2021
期刊：
影响因子：
3.4
通讯作者：
Imai Masayuki
中科院分区：
文献类型：
--
作者：
Urakami Naohito;Sakuma Yuka;Chiba Toshikaze;Imai Masayuki
我们使用粗粒度分子动力学模拟研究了脂质翻转引起的小单层囊泡（suv）的变形。在由零自发曲率脂质（ZLs）组成的单组分suv中，ZLs的翻转使气孔细胞形的suv变形为扁形，而梨形的suv变形为长形。这两种平衡形状符合弹性能的局部最小值。在由ZLs和负自发曲率脂质（NLs）组成的二元囊泡中，囊泡的变形途径取决于初始NL在双层中的分布。如果外叶和内叶的初始NL浓度差很小，则ZLs和NLs的“翻转”会使梨形suv迅速变形为平衡长形。另一方面，当NLs定位于内小叶时，ZLs和NLs的翻转使梨形suv变形成限制形状，然后诱导囊泡分裂。由于NLs的触发器速率比ZLs快得多，总自由能先被NLs的触发器放松，然后被ZLs的触发器放松。这种动力学效应是观察到的由人字拖引起的囊泡分裂的原因。
We investigated the deformation of small unilamellar vesicles (SUVs) induced by flip-flops of lipids using coarse-grained molecular dynamics simulations. In the case of single-component SUVs composed of zero spontaneous curvature lipids (ZLs), the flip-flop of ZLs deformed stomatocyte-shaped SUVs into an oblate shape, whereas pear-shaped SUVs were deformed into a prolate shape. These two equilibrium shapes comply with the local minima of elastic energy. In the case of binary vesicles composed of ZLs and negative spontaneous curvature lipids (NLs), the vesicle deformation pathway depended on the initial NL distribution in the bilayer. If the initial difference in the NL concentration between the outer and inner leaflets was small, the flip-flop of ZLs and NLs rapidly deformed pear-shaped SUVs into an equilibrium prolate shape. On the other hand, when NLs were localised in the inner leaflet, the flip-flop of ZLs and NLs deformed pear-shaped SUVs into a limiting shape and then induced vesicle division. Because the flip-flop rate of NLs is much faster than that of ZLs, the total free energy was first relaxed by the flip-flop of NLs and then by that of ZLs. This kinetic effect is responsible for the observed vesicle division induced by flip-flops.