REAL-TIME MONITORING OF MACROMOLECULAR ASSEMBLIES IN THE STATE OF FORMATION OR TRANSITION BY SMALL AND WIDE ANGLE X-RAY SCATTERING (SWAXS) AT ELLETRA
H. Amenitsch1, S. Bernstorff2, P. Dubcek2, M. Kriechbaum1, R. Menk2, G. Pabst1, M. Rappolt1, R. Schwarzenbacher1, M. Steinhart3 and P. Laggner1
1Institute for Biophysics and X-ray
Structure Research, Austrian Academy of Sciences, Steyrergasse
17, A-8010 Graz, Austria
2Sincrotrone Trieste, SS14, Km
163.5, I-34012 Bassovizza (TS), Italy
3Institute of Macromolecular
Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky
sqr. 2, Prague 6, Czech Republic
The Small and Wide Angle X-ray Scattering (SWAXS) high-flux wiggler beamline at ELETTRA has been designed specifically for time-resolved (resolution: < 1 ms) diffraction studies of non-crystalline and fibrous materials [1]. The beamline is working at 3 fixed energies [2], namely 5.4, 8 and 16 keV, and has a spatial resolution between 1 and 140 nm in the SAXS regime and between 0.12 and 0.94 nm in the WAXS regime. At the photon energy of 8 keV the flux at sample is 2 x 1012 ph/s corresponding to a flux density of 5 x 1011 ph/s (ELETTRA: 2 GeV and 250 mA). Experiments have been conducted on various types of samples systems, using several very different experimental set-ups [3]. Some examples are: - phase transitions in phospholipid systems, induced either by T-jumps of > 10 deg. centigrade / 2 ms using an erbium-glass laser, or by p-jumps of up to 3000 bar / 10 ms using a pressure cell, have been explored with 5 ms time resolution. - the protein denaturation of GroEl with GuHCl in a stopped-flow cell was monitored on a time scale of 1 s - Formation of hexagonal and lamellar phases in MCM-41 during synthesis (TEOS - Synthesis), which could be studied with a sampling rate of 100 ms. Furthermore some representative results highlighting the performance of the SAXS beamline and its sample stage will be presented.