SAXFELS project receives RÅC funding

CSSB Group leader Charlotte Uetrecht (Uni Siegen, HPI and DESY) and collaborators, Erik Marklund from Uppsala University and Carl Caleman from Uppsala University/DESY (CFEL) received funding from the Röntgen-Ångström Cluster (RÅC), a Swedish-German research collaboration, for their Small Angle X-ray Free Electron Laser Scattering (SAXFELS) project. This four-year project, with a combined funding of 1.75 million EUR, will develop a new method for examining macromolecular structures by integrating and developing powerful techniques for gas-phase sample manipulation with X-ray diffraction imaging.

To understand how biological molecules such as viral proteins function, research must examine the structures of these molecules. The new SAXFELS project will combine the strengths of two techniques used for structural determination: Native mass spectrometry (MS) amd small-angle X-ray scattering (SAXS). Native mass spectrometry (MS) takes macromolecular complexes from solution into to the gas phase and separates them according to their mass-to-charge ratios while SAXS is a powerful diffraction imaging technique that provides structural information about biomolecules in solution. “Combining the complementary strengths of SAXS and MS, we are planning to take SAXS to the gas phase at an X-ray free electron laser (XFEL) in this SAXFELS project,” explains Uetrecht.

SAXFELS will adapt the prototype delivery system developed by the Horizon 2020 project MS SPIDOC, which is coordinated by Charlotte Uetrecht. The existing delivery system, which transports subpopulations of a protein solution to the European XFEL SPB beamline, will be altered to accommodate gas phase SAXS at Eu XFEL’s Soft-X-ray Port (SXP), a beamline where users are able to set-up their own experiment stations. The new technique will be tested on various coronavirus proteins including SARS-CoV-2 nsp complexes.

“An oriented gas-phase SAXS for XFEL has not been developed anywhere else in the world and will make the SXP beamline unique,” explains Uetrecht “We will merge state-of-the-art MS techniques with diffractive imaging techniques at XFEL, to make a large technology leap for SAXS.” She also notes that the SAXFELS is a technique that the scientific community will be able to use at other X-ray facilities such as DESY’s PETRA III beamlines or Lund University’s MAX IV.

“Since its inception, CSSB has been collaborating with colleagues from Sweden with the help of RÅC funding,” notes Kay Gruenewald CSSB’s scientific director “SAXFELS is an exciting new project and I am looking forward to see it develop.”