GRAZING INCIDENCE SAXS ON SUBSTRATE SUPPORTED LIPID MEMBRANES

点击翻译按钮获取中文摘要

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.