Markvoort A J, van Santen R A, Hilbers P A J
Department of Biomedical Engineering, TU Eindhoven, Postbus 513, 5600 MB Eindhoven, The Netherlands.
J Phys Chem B. 2006 Nov 16;110(45):22780-5. doi: 10.1021/jp064888a.
Lipid bilayer membranes are known to form various structures such as large sheets or vesicles. When the two leaflets of the bilayer have an equal composition, the membrane preferentially forms a flat sheet or a spherical vesicle. However, a difference in the composition of the two leaflets may result in a curved bilayer or in a wide variety of vesicle shapes. Vesicles with different shapes have already been shown in experiments and diverse vesicle shapes have been predicted theoretically from energy minimization of continuous curves. Here we present a molecular dynamics study of the effect of small changes in the phospholipid headgroups on the spontaneous curvature of the bilayer and on the resulting vesicle shape transformations. Small asymmetries in the bilayers already result in high spontaneous curvature and large vesicle deformations. Vesicle shapes that are formed include ellipsoids, discoids, pear-shaped vesicles, cup-shaped vesicles, as well as budded vesicles. Comparison of these vesicles with theoretically derived vesicle shapes shows both resemblances and differences.
已知脂质双分子层膜会形成各种结构，如大的片层或囊泡。当双分子层的两个小叶具有相同的组成时，膜优先形成扁平片层或球形囊泡。然而，两个小叶组成的差异可能导致弯曲的双分子层或各种各样的囊泡形状。不同形状的囊泡已在实验中得到展示，并且从连续曲线的能量最小化理论上预测了多种囊泡形状。在此，我们展示了一项分子动力学研究，该研究探讨了磷脂头部基团的微小变化对双分子层自发曲率以及由此产生的囊泡形状转变的影响。双分子层中的微小不对称性已经导致了高自发曲率和大的囊泡变形。形成的囊泡形状包括椭球体、盘状体、梨形囊泡、杯形囊泡以及出芽囊泡。将这些囊泡与理论推导的囊泡形状进行比较，既显示出相似之处，也有不同之处。
