By measuring a series of diffraction pattern from a virus injected into an XFEL beam, researchers at Stanford’s Linac Coherent Light Source (LCLS) have determined the first three-dimensional structure of a virus, using a mimivirus.
X-ray crystallography has solved the vast majority of the structures of proteins and other biomolecules. The success of the method relies on growing large crystals of the molecules, which isn’t possible for all molecules.
“Free-electron lasers provide femtosecond X-ray pulses with a peak brilliance ten billion times higher than any previously available X-ray source,” the researchers note in a paper inPhysical Review Letters. “Such a large jump in one physical quantity is very rare, and can have far reaching implications for several areas of science. It has been suggested that such pulses could outrun key damage processes and allow structure determination without the need for crystallization.”
The current resolution of the technique (about 100 nanometers) would be sufficient to image important pathogenic viruses like HIV, influenza and herpes, and further improvements may soon allow researchers to tackle the study of single proteins, the scientists say.
Mimivirus is one of the largest known viruses. The viral capsid is about 450 nanometers in diameter and is covered by a layer of thin fibres. A 3D structure of the viral capsid exists, but the 3D structure of the inside was previously unknown.
Via Dr. Stefan Gruenwald