RICHLAND, Wash. -- In biology, a protein's shape is key to understanding how it causes disease or toxicity. Researchers who use X-rays to takes snapshots of proteins need a billion copies of the same protein stacked and packed into a neat crystal. Now, scientists using exceptionally bright and fast X-rays can take a picture that rivals conventional methods with a sheet of proteins just one protein molecule thick.
Using a type of laser known as XFEL, the technique opens the door to learning the structural details of almost 25 percent of known proteins, many of which have been overlooked due to their inability to stack properly. The team of researchers led by the Department of Energy's Pacific Northwest and Lawrence Livermore National Laboratories report their results with this unique form of X-ray diffraction in the March issue of the International Union of Crystallography Journal.
"In this paper, we're proving it's possible to use an XFEL to study individual monolayers of protein," said PNNL microscopist James Evans. "Just being able to see any diffraction is brand new."
Evans co-led the team of two dozen scientists with LLNL physicist Matthias Frank. The bright, fast X-rays were produced at the Linac Coherent Light Source at SLAC National Accelerator Laboratory in Menlo Park, Calif., the newest of DOE's major X-ray light source facilities at the U.S. National Laboratories. LCLS, currently the world's most powerful X-ray laser, is an X-ray free-electron laser. It produces beams millions of times brighter than earlier X-ray light sources.
Coming in at around 8 angstrom resolution (which can make out items a thousand times smaller than the width of a hair), the proteins appears slightly blurry but match the expected view based on previous research. Evans said this level of clarity would allow researchers, in some cases, to see how proteins change their shape as they interact with other proteins or molecules in their env
|Contact: Mary Beckman|
DOE/Pacific Northwest National Laboratory