Structural Biology Research Center, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Oho 1-1, Tsukuba, Ibaraki 305-0801, Japan.
Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Oho 1-1, Tsukuba, Ibaraki 305-0801, Japan.
Acta Crystallogr F Struct Biol Commun. 2021 Jan 1;77(Pt 1):29-36. doi: 10.1107/S2053230X20015514.
In 2003, a fully automated protein crystallization and monitoring system (PXS) was developed to support the structural genomics projects that were initiated in the early 2000s. In PXS, crystallization plates were automatically set up using the vapor-diffusion method, transferred to incubators and automatically observed according to a pre-set schedule. The captured images of each crystallization drop could be monitored through the internet using a web browser. While the screening throughput of PXS was very high, the demands of users have gradually changed over the ensuing years. To study difficult proteins, it has become important to screen crystallization conditions using small amounts of proteins. Moreover, membrane proteins have become one of the main targets for X-ray crystallography. Therefore, to meet the evolving demands of users, PXS was upgraded to PXS2. In PXS2, the minimum volume of the dispenser is reduced to 0.1 µl to minimize the amount of sample, and the resolution of the captured images is increased to five million pixels in order to observe small crystallization drops in detail. In addition to the 20°C incubators, a 4°C incubator was installed in PXS2 because crystallization results may vary with temperature. To support membrane-protein crystallization, PXS2 includes a procedure for the bicelle method. In addition, the system supports a lipidic cubic phase (LCP) method that uses a film sandwich plate and that was specifically designed for PXS2. These improvements expand the applicability of PXS2, reducing the bottleneck of X-ray protein crystallography.
2003 年，开发了一种全自动蛋白质结晶和监测系统（PXS），以支持 21 世纪初启动的结构基因组学项目。在 PXS 中，使用气相扩散法自动设置结晶板，根据预设的时间表转移到培养箱并自动观察。每个结晶液滴的捕获图像可以通过网络浏览器通过互联网进行监测。虽然 PXS 的筛选通量非常高，但用户的需求在接下来的几年中逐渐发生了变化。为了研究困难的蛋白质，使用少量蛋白质筛选结晶条件变得非常重要。此外，膜蛋白已成为 X 射线晶体学的主要目标之一。因此，为了满足用户不断发展的需求，PXS 已升级到 PXS2。在 PXS2 中，将分配器的最小体积减小到 0.1μl，以最小化样品量，并且捕获图像的分辨率增加到五百万像素，以便详细观察小的结晶液滴。除了 20°C 培养箱，PXS2 还安装了 4°C 培养箱，因为结晶结果可能随温度而变化。为了支持膜蛋白结晶，PXS2 包括一种用于双分子层方法的程序。此外，该系统支持使用薄膜三明治板的脂质立方相（LCP）方法，这是专门为 PXS2 设计的。这些改进扩展了 PXS2 的适用性，减少了 X 射线蛋白质晶体学的瓶颈。
