June 4, 2012

Intense X-ray technique opens the door to the future

(Ivanhoe Newswire) -- The structure of biomolecules is of great interest for medicine and biology because their shape often determines their function. The use of new tools called free-electron lasers (FELs) allows scientists to obtain high-resolution structural insight into macromolecules.

"The exceptionally intense X-ray pulses possible with FELs open the door for analyzing completely new classes of biomolecules like proteins from the cell membrane, that are hard or nearly impossible to crystallize," Henry Chapman, co-author and FEL scientist was quoted saying.

This new technology is so electrifying for the medical world. Using the Liniac Coherent Light Source (LCLS) allows an extreme breakdown of cell structures. The structure of a biomolecules is so valuable to scientists when creating medications. For example, when the structure of an enzyme critical to a cell receptor is known, it may be possible to design tailor-made medication. These structures are commonly determined by X-ray crystallography, in which crystallized samples are illuminated by an X-ray beam. The

X-ray light is utilized resulting in the diffraction pattern, which allows the molecular structure to be calculated. However, the crystallization of many biomolecules is difficult and slow, with large failure rates.

The X-ray flashes from X-ray lasers are extremely bright so that only the tiniest crystals are needed for a structure analysis. In fact, the micro crystals used in the study almost immediately vaporize when subjected to the intense X-ray light. A flash from LCLS is so short (only 5 million billionth of a second) that is passes through the sample, carrying with it the information to form the diffraction pattern, all before the crystal has started to explode.

"We were able to show that atomic resolution information can be collected before radiation damage has a chance to take effect. The key is ultra-short pulses. We see no effects of damage before the X-ray pulse has already passed." Anton Barty from the Chapman group added.

This technology opens a whole new world to biological insights and will allow scientists to embark on a new journey into creating medication.

Source: Science, May 2012