Time-resolved small-angle X-ray scattering system development for the biological macromolecules at SACLA: A pilot...

Area of Science:

• Biophysics
• Structural Biology
• X-ray Science

Background:

• Time-resolved small-angle X-ray scattering (SAXS) is crucial for studying protein dynamics in solution.
• Existing XFEL facilities offer high brilliance but require specialized setups for solution scattering.

Purpose of the Study:

• To establish a novel time-resolved SAXS system optimized for protein solution samples at an X-ray free-electron laser (XFEL).
• To demonstrate the system's capability in capturing structural dynamics of proteins under various conditions.

Main Methods:

• Integration of a helium path into the DAPHNIS system (designed for Serial Femtosecond Crystallography) to create a SAXS diffractometer.
• Utilizing a sample solution flow device for continuous sample delivery.
• Performing SAXS experiments on ovalbumin without triggers and on cytochrome c during acid denaturation.

Main Results:

• Successful establishment and validation of the time-resolved SAXS system at the SACLA XFEL facility.
• Acquisition of SAXS profiles for ovalbumin, demonstrating the system's baseline performance.
• Observation of denaturation-induced structural changes in cytochrome c.

Conclusions:

• The developed time-resolved SAXS system is effective for studying protein structural dynamics in solution using XFELs.
• The system enables investigations into protein folding, unfolding, and other conformational changes in response to triggers.
• This advancement opens new avenues for high-resolution structural biology research at XFELs.