SHORT- AND LONG-RANGE FORCES BETWEEN MEMBRANE SURFACES

溶剂中表面之间的分离由几个因素控制。 非特异性的短程和长程力，包括排斥力 水合作用和空间位阻力以及吸引性的货车范德华力。 提出了实验来测量和分析这些相互作用 （1）几种类型的磷脂和磷脂之间- 胆固醇双层和（2）含有糖脂的双层， 糖蛋白 水合作用和空间位阻力， 到双层的接近，将被测量为函数 用X射线衍射法测定相邻双层之间的分离 用已知的渗透和蒸气压缩的多层膜的分析 压力 电子密度分布将用于确定 双层结构和流体间距的每个应用值 压力 X射线衍射和量热实验是 设计用于确定水化力对 溶剂分子的尺寸和结构，组成， 和双层的性质。 水化力将是 作为脂质头群类型、头群 双层平面中的相关性（长程有序）， 膜组分如胆固醇，糖脂， 和N-烷基间苯二酚以及界面电位。 数据从这些 实验将被用来测试几个理论模型， 应提供有关物质基础的可靠信息， 水化力 压力间隔中的急剧向上的突破 在小的双分子层间分离的关系将表明开始 空间位阻 这些研究将表明， 各种磷脂、糖脂和糖蛋白修饰 膜间空间相互作用大小和范围 表面。 此外，将使用压力-间距关系 来确定货车范德华力的起源平面。 的 这个平面的精确位置和水合作用的大小 和空间位阻是计算 双分子层间粘附能和定量分析 膜融合

The separation between surfaces in solvent is governed by several non-specific short-and long-range forces, including the repulsive hydration and steric forces and the attractive van der Waals force. Experiments are proposed to measure and analyze these interactions between (1) several types of phospholipid and phospholipid- cholesterol bilayers and (2) bilayers containing glycolipids and glycoproteins. The hydration and steric forces, which provide the major barriers to the close approach of bilayers, will be measured as a function of separation between adjacent bilayers by x-ray diffraction analysis of multilayers compressed by known osmotic and vapor pressures. Electron density profiles will be used to determine the bilayer structure and fluid spacing for each value of applied pressure. X-ray diffraction and calorimetry experiments are designed to determine the dependence of the hydration force on the dimensions of the solvent molecule and the structure, composition, and properties of the bilayer. The hydration force will be measured as a function of lipid head group type, head group correlations (long-range order) in the plane of the bilayer, presence of membrane components such as cholesterol, glycolipids, and n-alkylresorcinol, and interfacial potential. Data from these experiments will be used to test several theoretical models, and should provide solid information on the physical basis of the hydration force. Sharp upward breaks in the pressure-spacing relation at small interbilayer separations will indicate the onset of steric hindrance. These studies will indicate the degree to which various phospholipids, glycolipids, and glycoproteins modify the magnitude and range of steric interactions between membrane surfaces. In addition, the pressure-spacing relations will be used to determine the plane of origin of the van der Waals force. The precise location of this plane and the magnitudes of the hydration and steric forces are essential parameters for calculations of interbilayer adhesion energies and for quantitative analyses of membrane fusion.