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The new European X-ray Free-Electron Laser is the first X-ray free-electron laser capable of delivering X-ray pulses with a megahertz inter-pulse spacing, more than four orders of magnitude higher than previously possible. However, to date, it has been unclear whether it would indeed be possible to measure high-quality diffraction data at megahertz pulse repetition rates. Here, we show that high-quality structures can indeed be obtained using currently available operating conditions at the European XFEL. We present two complete data sets, one from the well-known model system lysozyme and the other from a so far unknown complex of a β-lactamase from K. pneumoniae involved in antibiotic resistance. This result opens up megahertz serial femtosecond crystallography (SFX) as a tool for reliable structure determination, substrate screening and the efficient measurement of the evolution and dynamics of molecular structures using megahertz repetition rate pulses available at this new class of X-ray laser source., The new European X-Ray Free-Electron Laser (EuXFEL) is the first XFEL that generates X-ray pulses with a megahertz inter-pulse spacing. Here the authors demonstrate that high-quality and damage-free protein structures can be obtained with the currently available 1.1 MHz repetition rate pulses using lysozyme as a test case and furthermore present a β-lactamase structure.

Scientific reports 7, 44628 (2017). doi:10.1038/srep44628, Serial femtosecond crystallography requires reliable and efficient delivery of fresh crystals across the beam of an X-ray free-electron laser over the course of an experiment. We introduce a double-flow focusing nozzle to meet this challenge, with significantly reduced sample consumption, while improving jet stability over previous generations of nozzles. We demonstrate its use to determine the first room-temperature structure of RNA polymerase II at high resolution, revealing new structural details. Moreover, the double flow-focusing nozzles were successfully tested with three other protein samples and the first room temperature structure of an extradiol ring-cleaving dioxygenase was solved by utilizing the improved operation and characteristics of these devices., Published by Springer Nature, London

RTG1976 Symposium 'Structural Biology', Freiburg, Albert-Ludwigs-Universität Freiburg, Germany, 15 Oct 2015 - 16 Oct 2015 ; (2015).

Serial Femtosecond X-ray nanocrystallography (SFX) is a recently developed technique for protein structure determination that is based on collection of X-ray diffraction from nano- and microcrystals using a free electron laser (FEL). SFX is especially valuable for challenging proteins as membrane proteins, because the time-consuming process of growing larger crystals can be avoided. In general structural analysis with the use of free electron X-ray laser is a powerful method to overcome the radiation damage problem and to perform time-resolved structure analysis. Recent results of studies on the membrane protein complex Photosystem II using time resolved SFX will form the basis for future time-resolved studies of biomolecules. Furthermore an introduction of the concept of attosecond serial crystallography, which is currently under development, and its potential advantages over SFX will be given. Its capability for new insights in the water oxidation process in Photosystem II and its value for structural and functionals analysis of biological processes in general will be discussed.

Nuclear instruments & methods in physics research / A 829, 24-29(2016). doi:10.1016/j.nima.2016.02.080, X-ray crystallography is one of the main methods to determine atomic-resolution 3D images of the whole spectrum of molecules ranging from small inorganic clusters to large protein complexes consisting of hundred-thousands of atoms that constitute the macromolecular machinery of life. Life is not static, and unravelling the structure and dynamics of the most important reactions in chemistry and biology is essential to uncover their mechanism. Many of these reactions, including photosynthesis which drives our biosphere, are light induced and occur on ultrafast timescales. These have been studied with high time resolution primarily by optical spectroscopy, enabled by ultrafast laser technology, but they reduce the vast complexity of the process to a few reaction coordinates. In the AXSIS project at CFEL in Hamburg, funded by the European Research Council, we develop the new method of attosecond serial X-ray crystallography and spectroscopy, to give a full description of ultrafast processes atomically resolved in real space and on the electronic energy landscape, from co-measurement of X-ray and optical spectra, and X-ray diffraction. This technique will revolutionize our understanding of structure and function at the atomic and molecular level and thereby unravel fundamental processes in chemistry and biology like energy conversion processes. For that purpose, we develop a compact, fully coherent, THz-driven attosecond X-ray source based on coherent inverse Compton scattering off a free-electron crystal, to outrun radiation damage effects due to the necessary high X-ray irradiance required to acquire diffraction signals. This highly synergistic project starts from a completely clean slate rather than conforming to the specifications of a large free-electron laser (FEL) user facility, to optimize the entire instrumentation towards fundamental measurements of the mechanism of light absorption and excitation energy transfer. A multidisciplinary team formed by laser-, accelerator,- X-ray scientists and as well as spectroscopists and biochemists optimizes X-ray pulse parameters, in tandem with sample delivery, crystal size, and advanced X-ray detectors. Ultimately, the new capability, attosecond serial X-ray crystallography and spectroscopy, will be applied to one of the most important problems in structural biology, which is to elucidate the dynamics of light reactions, electron transfer and protein structure in photosynthesis., Published by North-Holland Publ. Co., Amsterdam