GRAZING INCIDENCE SAXS ON SUBSTRATE SUPPORTED LIPID MEMBRANES

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 可以在平坦光滑的表面上制备高度排列的脂膜堆叠，形成近晶C液晶结构，其中水插入由脂类分子形成的双层之间。这种膜堆被广泛用于沿双层法线集中于膜结构的衍射实验。在研究脂质-蛋白质相互作用时，观察蛋白质在膜平面上的横向分布也是非常有用的。在这个项目中，我们探索了利用掠入射小角度散射在底物支撑的膜上观察嵌入在膜上的蛋白质的排列的可能性。样品被对准在一个小硅片上，并安装在一个标准的测角仪头上。它被放在电动舞台上，以便轻松调整入射辐射的角度。使用较小的射束尺寸来限制样品上的足迹，我们确实可以检测到嵌入脂膜的多肽的第一个相关峰。目前正在建造的新样本室将允许我们在未来的实验中改变实验期间的样品温度和水化程度。这将使我们有可能观察和测量不同的脂膜环境对蛋白质分布的影响。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Highly aligned stacks of lipid membranes can be prepared on a flat smooth surface forming a smectic-C liquid crystal structure with water intercalated between the bilayers formed by the lipid molecules. Such membrane stacks have been extensively used for diffraction experiments concentrating on the structure of the membrane along the bilayer normal. In studying lipid-protein interactions it is also highly informative to look at the lateral distribution of the proteins in the membrane plane. In this project we explored the possibilities to use grazing incident small angle scattering on substrate supported membranes to look at the arrangement of proteins embedded in the membrane. The samples were aligned on a small silicon wafer and mounted on a standard goniometer head. This was put on a motorized stage for easy adjustment of the angle of the incident radiation. Using a small beam size to limit the footprint on the sample we could indeed detect the first correlation peak of the peptides embedded in the lipid membranes. The new sample chamber, that is currently being build, will allow us in future experiments to vary sample temperature and hydration during the experiment. This will give us the possibility to observe and measure the effects of the varying lipid membrane environment on the protein distribution.