Using macromolecular-crystallography beamline and microfluidic platform for small-angle diffraction studies of lipidic matrices for membrane-protein crystallization.
Using macromolecular-crystallography beamline and microfluidic platform for small-angle diffraction studies of lipidic matrices for membrane-protein crystallization.
复制标题
使用高分子晶体学光束线和微流体平台对膜蛋白结晶的脂质基质进行小角度衍射研究。
DOI：
10.1088/1742-6596/425/1/012013
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Brister,K
中科院分区：
文献类型：
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作者：
Kondrashkina,E;Khvostichenko,DS;Perry,SL;VonOsinski,J;Kenis,PJA;Brister,K
高分子晶体学（MX）光束线通常提供了改变X射线光束能量、将光束聚焦到数十微米大小、使用轴上视频显微镜在微衍射仪上对齐样本以及收集数据的可能性区域检测器位于三维空间。这些功能允许在相同的光束线上运行小角X射线散射和衍射（SAXS）的互补测量，并为标准MX设置添加了样品和检测器之间的真空路径、改进的光束停止和定制样品池。在先进光子源的21-ID-D MX光束线上，我们将真空飞行管连接到区域探测器支架上，并使用支架运动来对准内置在飞行管后端的光束停止器。在8 KeV的能量和1 m的样品到探测器的距离下，我们可以在倒易空间中实现0.01 A− 1的小角度分辨率。测量SAXS与此设置，我们已经研究了作为膜蛋白质结晶基质的介晶相的相图。结晶试验的结果显著地受结晶混合物的组成所决定的介晶中间相的结构的影响。我们使用微流控芯片的中间相配方和原位SAXS数据收集。使用MX光束线和微流控平台，我们已经证明了高通量SAXS研究的可行性，有利于筛选膜蛋白结晶的基质。
Macromolecular-crystallography (MX) beamlines routinely provide a possibility to change X-ray beam energy, focus the beam to a size of tens of microns, align a sample on a microdiffractometer using on-axis video microscope, and collect data with an area-detector positioned in three dimensions. These capabilities allow for running complementary measurements of small-angle X-ray scattering and diffraction (SAXS) at the same beamline with such additions to the standard MX setup as a vacuum path between the sample and the detector, a modified beam stop, and a custom sample cell. On the 21-ID-D MX beamline at the Advanced Photon Source we attach a vacuum flight tube to the area detector support and use the support motion for aligning a beam stop built into the rear end of the flight tube. At 8 KeV energy and 1 m sample-to-detector distance we can achieve a small-angle resolution of 0.01 A− 1 in the reciprocal space. Measuring SAXS with this setup, we have studied phase diagrams of lipidic mesophases used as matrices for membrane-protein crystallization. The outcome of crystallization trials is significantly affected by the structure of the lipidic mesophases, which is determined by the composition of the crystallization mixture. We use a microfluidic chip for the mesophase formulation and in situ SAXS data collection. Using the MX beamline and the microfluidic platform we have demonstrated the viability of the high-throughput SAXS studies facilitating screening of lipidic matrices for membrane-protein crystallization.