Tocanne J F, Cézanne L, Lopez A, Piknova B, Schram V, Tournier J F, Welby M
Laboratoire de Pharmacologie et Toxicologie Fondamentales du CNRS, Dpt III, Toulouse, France.
Chem Phys Lipids. 1994 Sep 6;73(1-2):139-58. doi: 10.1016/0009-3084(94)90179-1.
In the fluid mosaic model of membranes, lipids are organized in the form of a bilayer supporting peripheral and integral proteins. This model considers the lipid bilayer as a two-dimensional fluid in which lipids and proteins are free to diffuse. As a direct consequence, both types of molecules would be expected to be randomly distributed within the membrane. In fact, evidences are accumulating to indicate the occurrence of both a transverse and lateral regionalization of membranes which can be described in terms of micro- and macrodomains, including the two leaflets of the lipid bilayer. The nature of the interactions responsible for the formation of domains, the way they develop and the time- and space-scale over which they exist represent today as many challenging problems in membranology. In this report, we will first consider some of the basic observations which point to the role of proteins in the transverse and lateral regionalization of membranes. Then, we will discuss some of the possible mechanisms which, in particular in terms of lipid/protein interactions, can explain lateral heterogenities in membranes and which have the merit of providing a thermodynamic support to the existence of lipid domains in membranes.
在细胞膜的流动镶嵌模型中，脂质以双层形式排列，支撑着外周蛋白和整合蛋白。该模型将脂质双层视为二维流体，脂质和蛋白质可在其中自由扩散。直接的结果是，这两类分子预计会在膜内随机分布。事实上，越来越多的证据表明，膜存在横向和纵向区域化现象，这可以用微区和宏区来描述，包括脂质双层的两个小叶。导致形成这些区域的相互作用的本质、它们的发展方式以及它们存在的时间和空间尺度，如今都是膜生物学中诸多具有挑战性的问题。在本报告中，我们将首先考虑一些基本观察结果，这些结果表明蛋白质在膜的横向和纵向区域化中发挥的作用。然后，我们将讨论一些可能的机制，特别是从脂质/蛋白质相互作用的角度，这些机制可以解释膜中的横向异质性，并且有助于从热力学角度支持膜中脂质区域的存在。
