Taulier N, Nicot C, Waks M, Hodges R S, Ober R, Urbach W
Laboratoire d'Imagerie Paramétrique, UMR 7623 CNRS, Université Pierre et Marie Curie, 15 rue de l'Ecole de Médecine, 75270 Paris cédex 06, France.
Biophys J. 2000 Feb;78(2):857-65. doi: 10.1016/S0006-3495(00)76643-4.
We have used a lamellar phase made of a nonionic surfactant, dodecane and water, as a model membrane to investigate its interactions with macromolecular inclusions bringing together two membranes, i.e., acting as macromolecular snaps. In systems devoid of inclusions, the interlamellar distance depends on the total volume fraction of membranes Phi. We show that, in presence of a transmembrane protein, or of several de novo designed peptides of different length and composition, the lamellar phase undergoes a binding transition. Under such conditions, the interlamellar distance is no longer proportional to Phi(-1), but rather to the surface concentration of snaps within the membrane. It also appears that, in the presence of the hydrophobic segment of peptide snaps, the length of the inclusions must be at least equal to the hydrophobic length of the membrane to be active. Experimental results have been precisely fitted to a model of thermally stabilized membranes, decorated with snaps. However, in the presence of inclusions, the parameter describing the interactions between membranes, has to take into account the length of the inclusion to preserve good predictive capabilities.
我们使用了一种由非离子表面活性剂、十二烷和水组成的层状相作为模型膜，来研究其与将两个膜聚集在一起的大分子内含物的相互作用，即作为大分子卡扣。在没有内含物的系统中，层间距离取决于膜的总体积分数Φ。我们表明，在存在跨膜蛋白或几种不同长度和组成的从头设计肽的情况下，层状相会发生结合转变。在这种条件下，层间距离不再与Φ(-1)成正比，而是与膜内卡扣的表面浓度成正比。还发现，在存在肽卡扣的疏水片段的情况下，内含物的长度必须至少等于膜的疏水长度才能发挥作用。实验结果已精确拟合到一个用卡扣装饰的热稳定膜模型。然而，在存在内含物的情况下，描述膜之间相互作用的参数必须考虑内含物的长度，以保持良好的预测能力。
