PHASE-DIAGRAMS AND SHAPE TRANSFORMATIONS OF TOROIDAL VESICLES
PHASE-DIAGRAMS AND SHAPE TRANSFORMATIONS OF TOROIDAL VESICLES
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DOI：
10.1051/jp2:1993225
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发表时间：
1993-11-01
期刊：
影响因子：
--
通讯作者：
LIPOWSKY, R
中科院分区：
文献类型：
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作者：
JULICHER, F;SEIFERT, U;LIPOWSKY, R
在膜曲率模型的背景下，研究了具有环面拓扑结构的囊泡的形状。对于两种简化的曲率模型，即自发曲率（SC）模型和双层耦合（BC）模型，通过求解轴对称形状的形状方程，得到了能量图、静止形状片和相图的结构。系统地研究了三种不同的轴对称形状：1)盘状环面；Ii)镰状环面细胞和iii)环状口细胞。对对称破缺共形变换下的轴对称形状的稳定性分析表明，环面囊泡相图的大部分区域是非轴对称的，非轴对称形状是用共形变换近似确定的。为了将理论与实验进行比较，对SC模型和BC模型进行了推广，讨论了更为现实的脂质双分子层曲率模型——面积差弹性模型（ade -模型）。最近观察到的环状囊泡的形状可以在ade模型的相图中找到。我们预测温度变化对观察到的形状的影响。新的形状类型，环形口细胞，还没有被观察到。
Shapes of vesicles with toroidal topology are studied in the context of curvature models for the membrane. For two simplified curvature models, the spontaneous-curvature (SC) model and the bilayer-couple (BC) model, the structure of energy diagrams, sheets of stationary shapes and phase diagrams are obtained by solving shape equations for axisymmetric shapes. Three different sheets of axisymmetric shapes are investigated systematically: i) discoid tori; ii) sickle-shaped tori and iii) toroidal stomatocytes. A stability analysis of axisymmetric shapes with respect to symmetry breaking conformal transformations reveals that large regions of the phase diagrams of toroidal vesicles are non-axisymmetric, Non-axisymmetric shapes are determined approximately using conformal transformations. To compare the theory with experiments, a generalization of the SC and BC model, the area-difference-elasticity-model (ADE-model), which is a more realistic curvature model for lipid bilayers, is discussed. Shapes of toroidal vesicles which have been observed recently can be located in the phase diagram of the ADE-model. We predict the effect of temperature changes on the observed shapes. The new class of shapes, the toroidal stomatocytes, have not yet been observed.