High-viscosity injector-based pink-beam serial crystallography of microcrystals at a synchrotron radiation source

IUCrJ. 2019 Apr 5;6(Pt 3):412-425. doi: 10.1107/S205225251900263X. eCollection 2019 May 1.


Since the first successful serial crystallography (SX) experiment at a synchrotron radiation source, the popularity of this approach has continued to grow showing that third-generation synchrotrons can be viable alternatives to scarce X-ray free-electron laser sources. Synchrotron radiation flux may be increased ∼100 times by a moderate increase in the bandwidth ('pink beam' conditions) at some cost to data analysis complexity. Here, we report the first high-viscosity injector-based pink-beam SX experiments. The structures of proteinase K (PK) and A2A adenosine receptor (A2AAR) were determined to resolutions of 1.8 and 4.2 Å using 4 and 24 consecutive 100 ps X-ray pulse exposures, respectively. Strong PK data were processed using existing Laue approaches, while weaker A2AAR data required an alternative data-processing strategy. This demonstration of the feasibility presents new opportunities for time-resolved experiments with microcrystals to study structural changes in real time at pink-beam synchrotron beamlines worldwide.

Keywords: X-ray crystallography; injector-based serial crystallography; membrane proteins; pink-beam serial crystallography; protein structures; structural biology; structure determination; third-generation synchrotrons.