SCIENCE AT THE EDGE SEMINAR
QB/GEDD
Friday, October 22 at 11:30am
Room 1400 Biomedical and Physical Sciences Bldg.
Refreshments at 11:15
Petra Fromme
Department of Chemistry and Biochemistry, Arizona State University
Femtosecond Nanocrystallography of Membrane Proteins
Membrane proteins are of extreme importance for all living cells, but less than 300 membrane protein structures have been determined to date. First results of a novel concept for structure determination are presented, where X-ray diffraction “snapshots” are collected from a fully hydrated stream of nanocrystals, using femtosecond pulses from the world's first high energy X-ray free-electron laser, the Linac Coherent Light Source. The membrane protein Photosystem I, which is the most complex membrane that has been crystallized to date, consisting of 36 proteins and 381 cofactors, was used as a model system. Over 3 million diffraction patterns from individual nanocrystals (< 2 µm in size) were collected. By using femtosecond pulses briefer than the time-scale of most damage processes, the method may also overcome the problem of damage in crystallography. Femtosecond crystallography also opens a new avenue for determination of molecular movies of protein dynamics in the future.
This project is a large international collaboration, involving DESY, ASU Physics and Chemistry and Biochemistry as well as the CAMP group from three Max Plank Institutes, PIs include H. Chapman, J. Spence, P. Fromme, B. Doak, U. Weierstall, K Schmidt, , I. Schlichting, J. Ulrich, A. Barty, L. Struder, D. Rolles, the LCLS staff and the ASG team.
