Microsecond time-resolved X-ray scattering by utilizing MHz repetition rate at second-generation XFELs

Area of Science:

• Biophysics
• Structural Biology
• Biochemistry

Background:

• Understanding rapid structural changes in biomolecules is vital for numerous scientific fields.
• Existing methods often lack the speed or sensitivity to capture fleeting molecular dynamics.

Purpose of the Study:

• To introduce a novel time-resolved X-ray scattering technique for detecting microsecond structural perturbations in biomolecules.
• To demonstrate the application of this method in observing protein unfolding dynamics.

Main Methods:

• Utilizing MHz repetition rates at X-ray free-electron lasers (XFELs).
• Acquiring time-series data of protein scattering with ultra-low noise levels (0.001%).
• Applying the technique to study the Jɑ helix unfolding of a light-oxygen-voltage photosensory domain.

Main Results:

• Successfully generated microsecond time-series of protein scattering data.
• Achieved exceptionally low noise levels, enabling sensitive detection of structural changes.
• Provided direct observation of the Jɑ helix unfolding process.

Conclusions:

• The developed MHz XFEL time-resolved scattering approach is effective for observing microsecond biomolecular dynamics.
• This strategy is easy to implement and broadly applicable for studying various biochemical processes.
• Offers a powerful new tool for direct observation of structural dynamics in biological systems.