发表机构
Department of Physics and Astronomy, University College London（伦敦大学学院物理与天文系）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究通过小结构域能量模型，揭示膜曲率偏好由两个无量纲参数决定，并发现结构域大小通过线张力影响其在复杂膜上的定位，提出小结构域聚集后随生长迁移的机制。
AI 中文摘要
膜曲率已被证明会影响脂质或蛋白质结构域的定位，但弯曲刚度、自发曲率、高斯弯曲模量和线张力各自的作用通常难以区分。我们针对形状保持固定（例如通过强粘附于弯曲基底）的膜发展了一种小结构域描述。将局部Helfrich能量与小面积等周展开相结合，得到一个由局部平均曲率和高斯曲率决定的位置相关能量。我们识别出四种普遍的曲率偏好区域，其边界仅依赖于两个无量纲参数。在具有复杂曲率的特定膜形状上，我们表明这种曲率偏好决定了小结构域所经历的能量景观，这些景观通过线张力贡献强烈依赖于结构域的大小。例如，在扁球形膜上，非常小的结构域倾向于在极点处定位，而较大的结构域则偏好于赤道处。我们发现这种转变是连续的还是不连续的强烈依赖于结构域的自发曲率。这种排序提出了一种机制，小结构域可以在一个位置聚集并合并，然后随着它们生长而重新定位。
英文摘要
Membrane curvature has been shown to bias the location of lipid or protein domains, but the roles of bending rigidity, spontaneous curvature, Gaussian bending modulus, and line tension are difficult to separate in general. We develop a small-domain description for a membrane whose shape is held fixed, e.g. by strong adhesion to a curved substrate. Combining a local Helfrich energy with the small-area isoperimetric expansion gives a position-dependent energy determined by the local mean and Gaussian curvatures. We identify four generic regimes of curvature preference whose boundaries depend on only two dimensionless parameters. On specific membrane shapes with complex curvature, we show that this curvature preference determines the energy landscapes experienced by small domains, which are strongly dependent on the size of the domain through the line tension contribution. For example, on an oblate-shaped membrane, very small domains tend to localize at the poles, whereas larger domains prefer to localize at the equator. Whether this transition is continuous or discontinuous is found to strongly depend on the spontaneous curvature of the domain. This ordering suggests a mechanism by which small domains can collect and coalesce at one location before relocating as they grow.
CommentsInvited submission to Biophysical Journal's Special Issue "Foundations of Membrane Biophysics: Dedicated to Wolfgang Helfrich"
