Research For Serial Crystallography Experiment Technology Using Synchrotron Source

The X-ray diffraction using synchrotron radiation is the most important method presently to determine the three-dimensional structure of protein,and can obtain high-quality diffraction data of protein crystals efficiently.However,high-intensity synchrotron radiation on the protein crystal will produce radiation damage,resulting in structural information weakened and changed.The cryocrystallography technology can reduce the degree of damage on protein crystals caused by the high intensity of the X-ray beam,but the radiation damage problem is more prominent for microcrystals.In addition,cryocrystallography technology may also lead to some loss of fine structure information.It is the current problem for conventional synchrotron crystallography.Recently,serial crystallography has been widely used as a new method to analyze the structure of protein microcrystals,which has the advantages of room temperature acquisition,low radiation damage and time-resolved,and the development of serial crystallography is due to the emergence of free electron laser,the development of detector technology,the innovation of sample delivery method and the breakthrough of the data processing.The serial femtosecond crystallography based on free electron laser has succeeded in obtaining the damage-free diffraction data of protein microcrystal at room temperature and analyzed its high-resolution structure,which has led to the begin of serial synchrotron crystallography.To make full use of abundant experimental resources and characteristics of synchrotron radiation and solve the bottleneck of synchronous crystallography on microcrystallography,the researchers began to introduce the advantages of serial femtosecond crystallography to carry out related research,using different sample delivery methods.It is proved that the feasibility of serial synchrotron crystallography,and can solve the radiation dose limit of microcrystals at room temperature.Also,this way has the potential to conduct structural dynamics research on microsecond time scale.Therefore,this paper is domestic first reported on the theory and experimental research about serial synchrotron crystallography,to take advantage of the BL17U1 biological macromolecule beamline of Shanghai Synchrotron Radiation Facility,mainly adopts electrospinning sample loading technology to transport microcrystals,by controlling voltage and flow rate to obtain a stable micro-jet,combined with coaxial electrospinning and vacuum technology,the appropriate sister liquid to reduce the the sample freezing and condensation in vacuum,to extend the experimental time and avoid the sample charged,and it solves the practical application on synchrotron radiation.At the same time,the diffraction data of the lysozyme microcrystals are collected,and a large number of primitive diffraction patterns are preliminarily pretreated to screen the effective hit images,and the potential of serial synchrotron crystallography on the microsecond time scale is disscussed;however,limited by the hardware performance such as detector performance and light intensity density,they can not match the faster velocity of electrospinning at present,which leads to lower acquisition efficiency and data signal,not suitable for further structural analysis,but the experiment have proved its feasibility in synchrotron radiation,and provides valuable reference for future upgraded synchronous radiation beam station technology.