DOE Pulse
  • Number 333  |
  • March 21, 2011

An X-ray laser captures the structures of life

An X-ray laser captures the structures of life

An X-ray laser captures the
structures of life

Two studies published recently in Nature demonstrate how the unique capabilities of the world’s first hard X-ray free-electron laser—the Linac Coherent Light Source, located at DOE’s SLAC National Accelerator Laboratory—could revolutionize the study of life.

In one study, an international research team used the LCLS to demonstrate a shortcut for determining the 3-D structures of proteins.
The laser’s brilliant pulses of X-ray light pulled structural data from tiny
protein nanocrystals, avoiding the need to use large protein crystals
that can be difficult or impossible to prepare. This process could lop
years off the structural analysis of some proteins and allow scientists
to decipher tens of thousands of others that are out of reach
today, including many involved in infectious disease.

In a separate paper, the same team reported making the first single-shot images of intact viruses, paving the way for snapshots and movies of molecules, viruses and live microbes in action.

Since the publication of these papers, members of the research team have returned to SLAC to continue their studies of proteins involved in photosynthesis, parasitic disease and other important life processes. Using the Coherent X-ray Imaging instrument (CXI)—the fourth instrument to become operational since the LCLS opened for research in 2009—the researchers shined highly energetic “hard” X-rays at the photosynthetic protein complex Photosystem I and an enzyme that breaks down proteins, extracted from the parasite that causes African sleeping sickness. 

Though the results of these more recent studies won't be known until extensive analysis of the data has been completed, the researchers were extremely excited to see fine, crisply detailed protein structures at near atomic-scale resolution.  

"It's going very well," said SLAC researcher Marvin Seibert, grinning. "The fireworks are back. It's always fun."