Bitbol Anne-Florence, Fournier Jean-Baptiste
Université Paris Diderot, Paris 7, Sorbonne Paris Cité, Laboratoire Matière et Systèmes Complexes (MSC), UMR 7057 CNRS, Bâtiment Condorcet, Case Courrier 7056, F-75205 Paris Cedex 13, France.
Biochim Biophys Acta. 2013 Apr;1828(4):1241-9. doi: 10.1016/j.bbamem.2012.11.024. Epub 2012 Nov 29.
We study theoretically the spatiotemporal response of a lipid membrane submitted to a local chemical change of its environment, taking into account the time-dependent profile of the reagent concentration due to diffusion in the solution above the membrane. We show that the effect of the evolution of the reagent concentration profile becomes negligible after some time. It then becomes possible to extract interesting properties of the membrane response to the chemical modification. We find that a local density asymmetry between the two monolayers relaxes by spreading diffusively in the whole membrane. This behavior is driven by intermonolayer friction. Moreover, we show how the ratio of the spontaneous curvature change to the equilibrium density change induced by the chemical modification can be extracted from the dynamics of the local membrane deformation. Such information cannot be obtained by analyzing the equilibrium vesicle shapes that exist in different membrane environments in light of the area-difference elasticity model.
我们从理论上研究了脂质膜在其环境发生局部化学变化时的时空响应，同时考虑了由于试剂在膜上方溶液中扩散而导致的试剂浓度随时间的变化情况。我们表明，经过一段时间后，试剂浓度分布的演化效应变得可以忽略不计。然后就有可能提取出膜对化学修饰响应的有趣特性。我们发现，两个单层之间的局部密度不对称会通过在整个膜中扩散传播而弛豫。这种行为是由层间摩擦驱动的。此外，我们展示了如何从局部膜变形的动力学中提取化学修饰引起的自发曲率变化与平衡密度变化的比值。通过根据面积差弹性模型分析存在于不同膜环境中的平衡囊泡形状，无法获得此类信息。
