Microscope for crystallization trials

我们的实验室有兴趣了解细菌如何利用蛋白质来摄取必需和稀缺的营养铁。例如，致病细菌需要铁才能在受感染的宿主中生存。如果这些细菌无法从环境中获得足够的铁，它们就会挨饿。为了获得铁，细菌制造称为铁载体的分子，这些分子被分泌到环境中以吸收铁。在大肠杆菌中已经鉴定出大约12种蛋白质。大肠杆菌合成和分泌铁载体所必需。我们的研究涉及表征这些蛋白质以及它们如何相互作用。我们认为，它们的作用是协调在一个网络状的安排，以确保铁载体有效地合成和分泌。我们将描述铁载体生物合成和分泌的蛋白质的三维结构。要做到这一点，我们将纯化蛋白质，并试图结晶它们。然后，我们可以使用X射线来确定蛋白质的结构，通过测量X射线如何被晶体衍射。由于蛋白质晶体非常小（一般大小为10-500微米），我们需要使用强大的显微镜来监控我们在实验室中晶体的生长。我们还需要一种装置，将平面反射光通过晶体，因为蛋白质晶体改变颜色时，暴露于偏振光。这将使我们能够评估我们的蛋白质晶体的质量。最后，一个数字照片记录系统将使我们能够监控我们的结晶试验的进展。

Our laboratory is interested in learning how bacteria use proteins to uptake the essential and scarce nutrient iron. Pathogenic bacteria, for example, require iron for survival in infected hosts. If these bacteria cannot obtain enough iron from their environment, they will starve. To obtain iron, bacteria make molecules called siderophores, which are secreted into the environment to scavenge iron. About a dozen proteins have been identified in the bacterium E. coli as being necessary to synthesize and secrete siderophores. Our research involves characterizing these proteins and how they interact with each other. We believe that their action is coordinated in a network-like arrangement to make sure that siderophores are efficiently synthesized and secreted. We will characterize the three-dimensional structures of proteins involved in siderophore biosynthesis and secretion. To do this, we will purify the proteins and attempt to crystallize them. We can then use X-rays to determine the structures of the proteins by measuring how the X-rays are diffracted by the crystal. Since protein crystals are very small (generally 10-500 microns in size), we need to use a powerful microscope to monitor the growth of our crystals in the laboratory. We also need a device that will plane-polarize light through the crystal since protein crystals change colour when exposed to polarized light. This will allow us to assess the qualities of our protein crystals. Finally, a digital photodocumentation system will allow us to monitor the progress of our crystallization trials.