der Physikalischen Gesellschaft zu Berlin
im Sommersemester 2010
In diesem Max-von-Laue-Kolloquium sprach
Prof. Dr. Henry Chapman,
Center for Free-Electron Laser Science, DESY, Hamburg, und Universität Hamburg.
Titel, Termin, Moderation und Ort:
Since the discovery of X-rays by Röntgen in 1895, the brightness of X-ray sources has increased at an exponential rate. Today we have X-ray free-electron lasers that can produce brief pulses that have gigawatts of power of X-rays. The predominant scientific method that is utilized by high-brightness X-ray sources, and drives their development, is X-ray diffraction. As discovered in 1912 by von Laue, the short wavelength of the radiation matches the spacing of atoms, and the regularity of those atoms in crystals gives rise to strong diffraction that can be easily measured. X-ray crystallography has now been used to determine the molecular structures of over 63,000 proteins and protein complexes, primarily using synchrotron sources. However, many types of proteins cannot be easily crystallized. For example, less than 250 membrane protein structures have been solved. The short, intense pulses from X-ray free-electron lasers may enable X-ray diffraction from single, uncrystallized protein molecules, which will overcome this bottleneck. I will describe proof of principle experiments that we have carried out at the FLASH facility in Hamburg, and the Linac Coherent Light Source at the Stanford Linear Accelerator Center (SLAC) in Stanford, California.