Buckling Under Pressure: Curvature-Based Lipid Segregation and Stability Modulation in Cardiolipin-Containing Bilayers
Buckling Under Pressure: Curvature-Based Lipid Segregation and Stability Modulation in Cardiolipin-Containing Bilayers
复制标题
DOI：
10.1021/acs.langmuir.7b01185
复制
发表时间：
2017-07-11
期刊：
影响因子：
3.9
通讯作者：
May, Eric R.
中科院分区：
文献类型：
--
作者：
Boyd, Kevin J.;Alder, Nathan N.;May, Eric R.
线粒体内膜的形态和蛋白质结构影响线粒体的代谢功能。心磷脂(CL)是一种独特的四芳基脂类物质，参与维持线粒体内膜高度弯曲的形状以及呼吸和氧化磷酸化所需蛋白质的空间组织。心磷脂由于其倒置的锥形分子几何结构，已被认为可以自组织成脂类结构域，尽管这种组织的驱动力还不完全清楚。在这项工作中，我们使用粗粒分子动力学模拟来研究含和不含CL的非均相双层膜的力学性质和脂类动力学，作为膜曲率的函数。我们发现，CL的掺入增加了双分子层的变形能力，并且CL在负曲率较高的区域变得非常丰富。我们进一步证明，另一种线粒体倒锥形脂质，磷脂酰乙醇胺(PE)，不会以显著的方式分割或增加膜的变形性。因此，CL似乎具有一些独特的特征，不能简单地从分子几何角度来推断。
Mitochondrial metabolic function is affected by the morphology and protein organization of the mitochondrial inner membrane. Cardiolipin (CL) is a unique tetra-aryl lipid that is involved in the maintenance of the highly curved shape of the mitochondrial inner membrane as well as spatial organization of the proteins necessary for respiration and oxidative phosphorylation. Cardiolipin has been suggested to self-organize into lipid domains due to its inverted conical molecular geome though the driving forces for this organization are not fully understood. In this work, we use coarse-grained molecular dynamics simulations to study the mechanical properties and lipid dynamics in heterogeneous bilayers both with and without CL, as a function of membrane curvature. We find that incorporation of CL increases bilayer deformability and that CL becomes highly enriched in regions of high negative curvature. We further show that another mitochondrial inverted conical lipid, phosphatidylethanolamine (PE), does not partition or increase the deformability of the membrane in a significant manner. Therefore, CL appears to possess some unique characteristics that cannot be inferred simply from molecular geometry considerations.