Pink-beam serial crystallography

Area of Science:

• Structural Biology
• Biophysics
• X-ray Science

Background:

• Serial X-ray crystallography enables macromolecular structure determination at X-ray free electron lasers (XFELs) and synchrotron sources.
• Current time resolution for serial synchrotron crystallography is limited to millisecond timescales using monochromatic beams.

Purpose of the Study:

• To investigate the potential of polychromatic (pink) X-ray beams for time-resolved diffraction experiments at synchrotron sources.
• To achieve significantly shorter timescales than previously possible with monochromatic beams.

Main Methods:

• Utilized a pink-beam setup with a highly focused, high-photon-flux X-ray pulse (100 ps exposure) per crystal.
• Optimized the experimental setup for very low scattering background.
• Merged diffraction patterns from numerous small crystals to obtain complete datasets.

Main Results:

• Successfully determined the structures of two different protein samples.
• Required data from only 50 crystals, a significant reduction compared to monochromatic experiments.
• Achieved high-quality diffraction data, demonstrating the method's efficacy.

Conclusions:

• Pink-beam serial synchrotron crystallography enables structure determination at sub-microsecond timescales.
• This technique significantly enhances the study of rapid, irreversible biological reactions.
• High-brightness X-ray facilities can be leveraged for unprecedented time-resolved structural studies.