同步辐射光源下蛋白质晶体辐射损伤研究

Intense, tunable synchrotron x-ray radiation plays an important role in the determination of protein structure. When doing the diffraction experiment using X-ray, especially the X-ray generated by the third generation synchrotron, radiation damage could be introduced into the macromolecular crystal. With the development of the detector technology, the readout speed of the detector becomes very fast, which makes the achievement of shutter-free X-ray diffraction data collection method. However, few experiments have been done to show whether the shutter-free data collection method reduces the radiation damage of the crystals. In this project, shutter-free data collection method will be developed at the macromolecular crystallography beamline of National Facility for Protein Sciences(NFPS) using high readout speed detector Pilatus 6M. And a micro-focused beam platform will be built for small crystal X-ray diffraction data collection and radiation damage study. Using these platforms, the difference of macromolecular crystal radiation damage between traditional data collection method and shutter-free data collection method will be compared, which will verify a hypothesis that the shutter-free data collection could reduce the radiation damage. And radiation damage of protein crystal at different temperature will be studied when collecting data with shutter-free data collection method. In situ data collection at room temperature platform will also be established by using the robot with crystal plate grip ability. This method will be used for screening crystal and data collection at room temperature without picking up the crystals from the crystal plate.This project will not only provide a theoretical reference for radiation damage when collecting data at synchrotron, but also improve the efficiency and data quality of the beamline by developing new data collection platform.

依托同步辐射光源晶体学线站的相关技术已成为当前推动蛋白质结构测定快速发展的最重要技术。然而在使用同步辐射X射线进行晶体衍射数据收集的过程中，X射线常常会通过离子化过程造成晶体的辐射损伤。随着同步辐射线站新技术的发展，出现了新型高效的无快门数据收集方式。目前国际上对于这种数据收集方式下的晶体辐射损伤的程度和机制的研究还很少。本课题旨在依托三代同步辐射光源的生物大分子晶体学线站，通过对无快门数据收集方式和传统数据收集方式下晶体辐射损伤程度及机制进行对比研究，更加深入的了解晶体同步辐射损伤的机理。同时在研究过程中开发微聚焦平台搭建、无快门数据收集方式、使用机械手常温下扫板进行数据筛选和收集等线站相关的先进技术，减少晶体衍射数据收集时的辐射损伤的同时在我国的三代同步辐射晶体学线站上实现新型的数据收集方式。通过这些方法和平台的建设提高线站的使用效率，提高晶体衍射数据的质量。