Serial macromolecular crystallography at ALBA Synchrotron Light Source.

Area of Science:

• Structural Biology
• Biophysics
• Crystallography

Background:

• Serial synchrotron crystallography (SSX) is increasingly adopted at synchrotron sources.
• Over 40 SSX experiments have been reported, demonstrating its growing utility.
• Advancements in sample delivery are crucial for maximizing SSX capabilities.

Purpose of the Study:

• To report the first SSX experiments utilizing viscous jets at the ALBA beamline BL13-XALOC.
• To demonstrate the feasibility of determining high-resolution protein structures from microcrystals using this technique.
• To assess the suitability of BL13-XALOC as an alternative to X-ray free-electron lasers.

Main Methods:

• Microcrystals (15-30 µm) of five soluble proteins were suspended in lipidic cubic phase (LCP).
• A high-viscosity injector delivered samples to the X-ray beam at ALBA beamline BL13-XALOC.
• Complete diffraction data sets were collected and processed for structure determination.

Main Results:

• High-resolution structures were determined for all five tested proteins (lysozyme, proteinase K, phycocyanin, insulin, α-spectrin-SH3 domain).
• Excellent diffraction data quality was achieved, with no significant radiation damage observed.
• Atomic resolution structures were obtained from microcrystals as small as 15 µm.

Conclusions:

• The ALBA beamline BL13-XALOC is capable of atomic resolution structure determination using viscous jets at room temperature.
• This SSX approach provides a practical alternative to X-ray free-electron lasers for macromolecular structure determination.
• Viscous jet delivery in LCP is effective for serial crystallography with microcrystals.