March 14, 2013For decades, biochemists and biophysicists have worked to reveal the relationship between protein structural complexity and function, only to discover more complexity. They relied on freeze-trapping to capture protein intermediates at various steps along a biochemical pathway. Now a research group has developed the necessary infrastructure at the BioCARS beamline at the Argonne Advanced Photon Source to watch proteins function in real time on the picosecond time scale. Their work brings us many steps closer to knowing how proteins function, or malfunction when leading to disease.
Time-Resolved Research (X-ray Science Division)
The TRR groups has full and partial operational responsibility for 7 experimental stations at 5 beamlines. There are 6 undulator end stations (7-ID-B, 7-ID-C, 7-ID–D, 8-ID-E, 8-ID-I and 14-ID-B) and one bending magnet end station (7-BM-B). Time-resolved pump-probe techniques using, most often, high-power lasers as the pump, are performed in stations 7-ID-C and 7-ID-D and 14-ID-B [which the X-ray Science Division (XSD) runs in partnership with BioCARS]. 7-ID-B is white-beam capable and hosts experiments that probe ultrafast fluid dynamics in high-pressure, high velocity sprays. Station 7-BM-B complements the work performed in 7-ID-B by performing spatial mapping of high pressure, high velocity sprays and aerosols via time-resolved radiography and fluorescence measurements. 8-ID-E primarily supports grazing-incidence scattering (GIXS) devoted to measuring the morphology of organic thin films. 8-ID-I, and to a lesser extent 8-ID-E, apply x-ray photon correlation spectroscopy (XPCS) to study the stability of and very low energy excitations in soft (8-ID-I) and hard (8-ID-E) materials. In addition to the x-ray-beamlines, our group maintains and enhances high-power ultrafast laser systems at 7-ID and 14-ID.
Laser SystemsSpecifications below provide general guidelines. Specific capabilities and requirements should be discussed with the beamline staff.
|System||Station||Rep-rate||Pulse Length||Wavelength||Energy per Pulse|
|Ti:Sapph||7-ID-C, 7-ID-D||1 kHz||100 fs||800, 400 nm||200 μJ|
|Ti:Sapph with OPA||7-ID-C||1 kHz||100 fs||200nm - 20 μ||10 μJ|
|Duetto*||7-ID-D||54 kHz - 6.5 MHz||10 ps||1 or 0.5 μm||10 μJ|
|Spectra Ti:Sapph||14-ID-B||< 1 KHz||1 ps||350 nm - 2 μm||200 μJ|
*Portable system primarily operated and maintained by XSD-AMO in Station 7-ID-D. Available for use in other stations via collaboration or permission of XSD-AMO group and with appropriate safety considerations.