The first demonstration of 2 kHz time-resolved serial crystallography data acquisition at a fourth-generation synchrotron, using the JUNGFRAU 4M pixel detector.

Significance The extremely short and bright X-ray pulses produced by X-ray free-electron lasers unlock new opportunities in crystallography-based structural biology research. Efficient methods to deliver crystalline material are necessary due to damage or destruction of the crystal by the X-ray pulse. Crystals for the first experiments were 5 µm or smaller in size, delivered by a liquid injector. We describe a highly automated goniometer-based approach, compatible with crystals of larger and varied sizes, and accessible at cryogenic or ambient temperatures. These methods, coupled with improvements in data-processing algorithms, have resulted in high-resolution structures, unadulterated by the effects of radiation exposure, from only 100 to 1,000 diffraction images.

Structure-property investigation of crystalline amino acids is an important challenge since interactions between individual molecular fragments or even structural domains in the structure can simulate interactions in more complicated biological systems such as proteins and peptides.Besides, crystalline amino acids are applied as drugs, as piezoelectric and nonlinear optical materials.Therefore understanding a crystal structure response to variation in temperature and pressure is significant in such applications.Cysteine is a remarkable amino acid because its side-chain residue contains a sulfhydryl group involved in formation of additional labile hydrogen bonds (S-H…S or S-H…O).The presence of these very weak bonds in the structure allows cysteine to take a peculiar place between hydrophobic (no contribution of side-chains to H-bonds) and hydrophilic amino acids (with that contribution).In the present contribution we discuss an evolution of chiral and racemic cysteine crystal structures on cooling and on increasing pressure followed by X-ray crystallography and Raman spectroscopy.We also compare their behavior with that of cysteine crystalline salts and derivatives.The study was supported by the Projects of RAS (21.44, 5.6.4),SB RAS (Projects 13 & 109), grants from RFBR (09-03-00451, 10-03-00252), a BRHE grant from the CRDF (RUX0-008-NO-06) and FASI (RF) Contracts No GK P2529 & 16.740.11.0166.

Complete automation of the macromolecular crystallography experiment has been achieved at SSRL through the combination of robust mechanized experimental hardware and a flexible control system with an intuitive user interface. These highly reliable systems have enabled crystallography experiments to be carried out from the researchers' home institutions and other remote locations while retaining complete control over even the most challenging systems. A breakthrough component of the system, the Stanford Auto-Mounter (SAM), has enabled the efficient mounting of cryocooled samples without human intervention. Taking advantage of this automation, researchers have successfully screened more than 200 000 samples to select the crystals with the best diffraction quality for data collection as well as to determine optimal crystallization and cryocooling conditions. These systems, which have been deployed on all SSRL macromolecular crystallography beamlines and several beamlines worldwide, are used by more than 80 research groups in remote locations, establishing a new paradigm for macromolecular crystallography experimentation.

Since June 2005, the macromolecular crystallography users of the Stanford Synchrotron Radiation Laboratory (SSRL) have had the option to conduct diffraction experiments from their home institutions and other remote locations by means of advanced software tools that enable network-based control of highly automated beam lines. Remote experimenters have access to the same tools as local users, and have the capability to mount, center, and screen crystalline samples, and to collect, analyze, and backup diffraction data. Automated sample mounting is accomplished with the Stanford Auto-Mounting System (SAM) [1–3 Cohen, A. E., McPhillips, S. E., Song, J., Miller, M. D. and for the SSRL SMB and JCSG Groups. 2005. Automation of High-Throughput Protein Crystal Screening at SSRL. Synch. Rad. News, 18: 28–35. Van den Bedem, H., Miller, M. D., Wolf, G. and for the SSRL SMB and JCSG Groups. 2003. Towards Automated Data Collection at the Stanford Synchrotron Radiation Laboratory. Synch. Rad. News, 16: 15 Cohen, A. E., Ellis, P. J., Miller, M. D., Deacon, A. M. and Phizackerley, R. P. 2002. An Automated System to Mount Cryo-Cooled Protein Crystals on a Synchrotron Beamline, Using Compact Sample Cassettes and a Small-Scale Robot. J. Appl. Cryst., 35: 720–726. ], beamline and experimental control is carried out using Blu-Ice/DCS [4 McPhillips, T. M., McPhillips, S. E., Chiu, H. -J., Cohen, A. E., Deacon, A. M., Ellis, P. J., Garman, E., González, A., Sauter, N. K., Phizackerley, R. P., Soltis, S. M and Kuhn, P. 2002. Blu-Ice and the Distributed Control System: Software for Data Acquisition and Instrument Control at Macromolecular Crystallography Beamlines. J. Synchrotron Rad., 9: 401–406. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]], and additional remote monitoring of the experiment and data backup is supported with several web-based applications [5 Eriksson, T., Chiu, H.-J., Sharp, K., McPhillips, T., McPhillips, S., Sauter, N., Soltis, M. and Kuhn, P. 2002. Collaboratory for Macromolecular Crystallography at SSRL. Acta Cryst., A58(Supplement): C73 [Google Scholar]]. The highly graphical applications and computational resources at SSRL are accessed through a client/server application that uses minimal resources on the client side and has a typical response close to that obtained at the beamline.

ChemMatCARS, a synchrotron-based national facility for Chemistry and Materials Science located at the Advanced Photon Source, is developing strong programs in time-resolved, chargedensity, and micro (~10 µm) crystallography.This presentation will focus on the time-resolved and charge-density capabilities at the sector.In small-molecule time-resolved studies, monochromatic x-rays are used to probe optically pumped molecular excited states.Experiments are performed using a rotating chopper wheel to gate the x-ray source and trigger the laser.Results show significant changes in molecular structure after laser excitation [1].Recently, several experimental runs were devoted to assessing whether or not the beamline/instrument quality was sufficient for precision charge-density measurements [2].For these high-resolution studies, a relatively short wavelength is used ( =0.42 Å) typically yielding an instrument resolution of 1.34 Å -1 .These experiments produced R internal values as low as R int ~0.02.