von Tscharner V, McConnell H M
Biophys J. 1981 Nov;36(2):421-7. doi: 10.1016/S0006-3495(81)84741-8.
A method for transferring a lipid monolayer from an air-water interface to an alkylated glass slide is described. Specific antibodies bind tightly to lipid haptens contained in these monolayers on the glass slides. We conclude that the polar head groups of the lipids face the aqueous phase. A monolayer containing a fluorescent lipid was used to show that the monolayer is homogeneous as observed with an epifluorescence microscope. A periodic pattern photobleaching technique was used to measure the lateral diffusion of this fluorescent lipid probe in monolayers composed of dipalmitoyl phosphatidylcholine and dimyristoyl phosphatidylcholine. Different regions of the pressure-area isotherms of the monolayers at the air-water interface can be correlated with the diffusion of the fluorescent probe molecules on the monolayer-coated glass slide. Monolayers derived from the so-called "solid-condensed" state of a monolayer at the air-water interface showed a very low probe diffusion coefficient in this monolayer when placed on a glass slide, D </= 10(-10) cm(2)/s. Monolayers derived from the "liquid condensed/liquid expanded" (LC/LE) region of the monolayer isotherms at the air-water interface showed rapid diffusion (D > 10(-8) cm(2)/s) when these same monolayers were observed on an alkylated glass slide. The monolayers attached to the glass slide appear to be homogeneous when derived from monolayers in the LC/LE region of monolayers at the air-water interface. There is no major variation of the diffusion coefficient of a fluorescent lipid probe when this diffusion is measured on a lipid monolayer on a glass slide, for monolayers derived from various regions of the LC/LE monolayers at the air-water interface. This is consistent with the view that the LC/LE region is most likely a single fluid phase. Monolayers supported on a planar glass substrate are of much potential interest for biophysical and biochemical studies of the interactions between model membranes and cellular membranes, and for physical chemical studies relating the properties of lipid monolayers to the properties of lipid bilayers.
本文描述了一种将脂质单分子层从气-水界面转移至烷基化载玻片的方法。特异性抗体紧密结合于载玻片上这些单分子层中所含的脂质半抗原。我们得出结论，脂质的极性头部基团面向水相。使用含有荧光脂质的单分子层来表明，如通过落射荧光显微镜观察到的那样，该单分子层是均匀的。采用周期性图案光漂白技术来测量这种荧光脂质探针在由二棕榈酰磷脂酰胆碱和二肉豆蔻酰磷脂酰胆碱组成的单分子层中的横向扩散。气-水界面上单分子层的压力-面积等温线的不同区域可与荧光探针分子在单分子层包覆的载玻片上的扩散相关联。当置于载玻片上时，源自气-水界面上单分子层所谓“固态凝聚”态的单分子层在此单分子层中显示出非常低的探针扩散系数，D≤10⁻¹⁰ cm²/s。当在烷基化载玻片上观察这些相同的单分子层时，源自气-水界面上单分子层等温线“液态凝聚/液态扩张”（LC/LE）区域的单分子层显示出快速扩散（D＞10⁻⁸ cm²/s）。当源自气-水界面上单分子层LC/LE区域的单分子层附着于载玻片时，其似乎是均匀的。对于在载玻片上的脂质单分子层测量荧光脂质探针的扩散系数时，对于源自气-水界面上LC/LE单分子层不同区域的单分子层而言，扩散系数没有重大变化。这与LC/LE区域很可能是单一流体相的观点一致。支撑在平面玻璃基板上的单分子层对于模型膜与细胞膜之间相互作用的生物物理和生物化学研究，以及对于将脂质单分子层性质与脂质双层性质相关联的物理化学研究具有很大的潜在意义。
