脂质膜中的畴生长与出芽不稳定性
Domain growth in lipid membranes and the budding instability
- Institut Charles Sadron, CNRS UPR22 & Université de Strasbourg（斯特拉斯堡大学）
- University of Lyon, ENS-Lyon, CNRS UMR 5182, Chemistry Laboratory（里昂大学）
- Center for Physics and Chemistry of Living Systems, Tel Aviv University（特拉维夫大学）
- School of Chemistry & Center for Physics and Chemistry of Living Systems, Tel Aviv University（特拉维夫大学）
- Zhejiang Key Laboratory of Soft Matter Biomedical Materials, Wenzhou Institute, University of Chinese Academy of Sciences（中国科学院大学温州研究所）
机构由 AI 辅助整理，请以论文原文为准。
中文总结 AI 辅助
本文研究相分离脂质膜中圆形畴的生长动力学，发现畴尺寸随时间先按t^{1/3}后按t^{1/2}增长，并结合线张力与准静态准则预测出芽不稳定性时间，揭示畴尺寸和线张力演化对出芽的关键作用。
中文摘要 AI 辅助
我们研究了相分离脂质膜中圆形畴的生长及其与出芽不稳定性的关系。我们在径向对称性下用守恒的、含时的金兹堡-朗道模型描述面内动力学。数值解显示畴尺寸$D$作为时间$t$的函数存在交叉行为：早期$D\sim t^{1/3}$，后期$D\sim t^{1/2}$，随后因有限系统尺寸而饱和。从演化的浓度剖面评估的含时线张力$\sigma(t)$在接近平面界面值之前迅速上升。这种行为区分了早期线张力主导的机制和后期畴尺寸主导的机制。为估计出芽不稳定性，我们将$D(t)$和$\sigma(t)$与部分出芽畴失去稳定性的准静态准则相结合。出芽不稳定性时间随膜自发曲率增加而减少，并在临界点附近增加。因此，畴尺寸和线张力的演化对于确定出芽不稳定性所需的时间至关重要。
英文摘要
We investigate the growth of a circular domain in a phase-separating lipid membrane and its relation to the budding instability. We describe the in-plane dynamics with a conserved, time-dependent Ginzburg-Landau model under radial symmetry. Numerical solutions show a crossover of the domain size $D$ as a function of time $t$ from $D\sim t^{1/3}$ at early times to $D\sim t^{1/2}$ at later times, followed by saturation due to finite system size. The time-dependent line tension $σ(t)$, evaluated from the evolving concentration profile, rises rapidly before approaching the planar-interface value. This behavior distinguishes an early line-tension-dominated regime from a later domain-size-dominated regime. To estimate the budding instability, we combine $D(t)$ and $σ(t)$ with a quasistatic criterion for the loss of stability of a partially budded domain. The budding-instability time decreases with increasing membrane spontaneous curvature and increases near the critical point. Thus, the evolution of both domain size and line tension is essential for determining the time required for the budding instability.
