Langmuir monolayers to study interactions at model membrane surfaces
Langmuir monolayers to study interactions at model membrane surfaces
复制标题
DOI：
10.1016/s0001-8686(02)00071-4
复制
发表时间：
2003-02-28
影响因子：
15.6
通讯作者：
Möhwald, H
中科院分区：
文献类型：
--
作者：
Brezesinski, G;Möhwald, H
朗缪尔单分子膜在液体-空气界面是定义明确的界面系统，因此，优秀的模型系统，以了解在界面上的相互作用超出了经典的DLVO描述。许多参数可以在很宽的范围内独立变化，并且可以以埃的精度分析结构。在论文的第一部分，两亲分子组成的单分子膜中的丰富的多态性进行了论证。利用同系物系列可以导出一般相图。相互作用的微妙的相互作用导致了丰富的阶段，这反过来又可以用来衡量这些相互作用的细微变化。基于对纯或混合脂质单分子膜中多态性的理解，人们可以研究溶解在亚相中的分子与单分子膜的相互作用。所呈现的样品是由酶催化的化学反应和聚电解质与带相反电荷的单分子膜的偶联。为了关联结构和反应性，可以研究界面处的酶的活性，主要结合X射线衍射和FTIR光谱。结果表明，活性依赖于单层结构。在一种情况下，反应产物导致单层中的结构变化并停止反应，因此，表明通过膜的产物抑制的微妙情况。另一方面，它已成为可能的操纵组织的聚电解质在界面处通过脂质电荷密度和离子强度。在最重要的情况下，DNA与膜表面的相互作用，我们表明，DNA排列在界面上的层状方式，和分子间的距离，通过同步辐射X-射线衍射测量的脂质密度可以改变。(C)2002 Elsevier Science B.V保留所有权利。
Langmuir monolayers at the liquid-air interface are well-defined interfacial systems and, therefore, excellent model systems to learn about interactions at interfaces beyond the classical DLVO description. Many parameters can be independently varied over a broad range and the structure can be analyzed with Angstrom precision. In the first part of the paper, the rich polymorphism in monolayers composed of amphiphilic molecules is demonstrated. Using homologues series generic phase diagrams can be derived. The delicate interplay of interactions causes a richness of phases which in turn can be used to measure fine variations in these interactions. Based on the understanding of the polymorphism in pure or mixed lipid monolayers, one can study the interaction of molecules dissolved in the subphase with monolayers. Samples presented are chemical reactions catalyzed by enzymes and coupling of polyelectrolytes to oppositely charged monolayers. To relate structure and reactivity, the activity of enzymes at the interface can be studied, predominantly combining X-ray diffraction and FTIR-spectroscopy. It is shown that the activity depends on monolayer structure. In one case, the reaction product leads to structural changes in the monolayer and stops the eaction, hence, indicating a subtle case of product inhibition via the membrane. On the other hand it has become possible to manipulate the organization of polyelectrolytes at interfaces via lipid charge density and ionic strength. In the most important case of DNA interacting with a membrane surface we show that DNA arranges at the interface in a lamellar manner, and the intermolecular distances, measured by Synchrotron X-ray diffraction can be varied by the lipid density. (C) 2002 Elsevier Science B.V All rights reserved.