IUCrJ (Jul 2015)

A novel inert crystal delivery medium for serial femtosecond crystallography

  • Chelsie E. Conrad,
  • Shibom Basu,
  • Daniel James,
  • Dingjie Wang,
  • Alexander Schaffer,
  • Shatabdi Roy-Chowdhury,
  • Nadia A. Zatsepin,
  • Andrew Aquila,
  • Jesse Coe,
  • Cornelius Gati,
  • Mark S. Hunter,
  • Jason E. Koglin,
  • Christopher Kupitz,
  • Garrett Nelson,
  • Ganesh Subramanian,
  • Thomas A. White,
  • Yun Zhao,
  • James Zook,
  • Sébastien Boutet,
  • Vadim Cherezov,
  • John C. H. Spence,
  • Raimund Fromme,
  • Uwe Weierstall,
  • Petra Fromme

DOI
https://doi.org/10.1107/S2052252515009811
Journal volume & issue
Vol. 2, no. 4
pp. 421 – 430

Abstract

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Serial femtosecond crystallography (SFX) has opened a new era in crystallography by permitting nearly damage-free, room-temperature structure determination of challenging proteins such as membrane proteins. In SFX, femtosecond X-ray free-electron laser pulses produce diffraction snapshots from nanocrystals and microcrystals delivered in a liquid jet, which leads to high protein consumption. A slow-moving stream of agarose has been developed as a new crystal delivery medium for SFX. It has low background scattering, is compatible with both soluble and membrane proteins, and can deliver the protein crystals at a wide range of temperatures down to 4°C. Using this crystal-laden agarose stream, the structure of a multi-subunit complex, phycocyanin, was solved to 2.5 Å resolution using 300 µg of microcrystals embedded into the agarose medium post-crystallization. The agarose delivery method reduces protein consumption by at least 100-fold and has the potential to be used for a diverse population of proteins, including membrane protein complexes.

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