11th International Workshop on X-ray Radiation Damage to Biological Samples - RD11

Session

Session 3 - Damage at New Sources - XFEL and 4th generation synchrotrons

15 Oct 2020, 13:00

WBGB/019 (Paul Scherrer Institut)

34. UV-induced cleavage and geminate recombination of the disulfide bond motif followed via ultrafast X-ray absorption spectroscopy

Nils Huse (U. Hamburg)

15/10/2020, 13:00

Invited

We investigated photocleavage of the disulfide bond motif in model compounds such as cysteine dimer (L-cystine) by time-resolved X-ray absorption spectroscopy [1,2]. We follow changes in X-ray absorption at the sulfur K-edge (2.5 keV) that appear to be unique to thyil (R-S∙) radicals, thereby tracking the fate of the disulfide bond. Ultrafast spectroscopy has revealed homolytic S-S bond...

15. Structural dynamics in proteins induced by and probed with X-ray free-electron laser pulses

Alexander Gorel (Max-Planck-Insitute for Medical Research Heidelberg)

15/10/2020, 13:30

Invited

X-ray free-electron lasers (XFELs) enable crystallographic structure determination beyond the limitations imposed upon synchrotron measurements by radiation damage. The need for very short XFEL pulses can be relieved through gating of Bragg diffraction by loss of crystalline order as damage progresses but not if ionization events are spatially non-uniform due to underlying elemental...

37. Specific radiation damage is a lesser concern at room temperature

Dr Antoine Royant (ESRF)

15/10/2020, 14:00

Invited

There are two types of radiation damage in protein X-ray crystallography [1]. The first one, global damage, has been known since the beginning of X-ray crystallography. Global damage accounts for the decrease in the diffraction properties of a crystal during data collection due to the interaction of X-rays with the atoms of the crystal, which, in particular, generates free electrons and...

44. Radiation damage in serial synchrotron crystallography at cryo- and room temperature

Nicolas Coquelle (University Grenoble Alpes)

15/10/2020, 14:50

X-ray crystallography is the most-prolific technique in structural biology but suffers from radiation damage, which limits the accuracy of the macromolecular structures. The introduction of cryo-cooling techniques greatly reduced the global radiation damage rate and was standardized on all X-ray crystallography beamlines at synchrotrons over the past decades. With the recent advent of serial...

25. Is radiation damage the limiting factor in high-resolution single particle imaging with X-ray free-electron lasers?

Carl Caleman (Uppsala University)

15/10/2020, 15:20

Invited

The prospect of single particle imaging with atomic resolution is one of the scientific drivers for the development of X-ray free-electron lasers. The assumption since the beginning has been that damage to the sample caused by intense X-ray pulses is one of the limiting factors for achieving subnanometer X-ray imaging of single particles and that X-ray pulses need to be as short as possible....

14. Avoiding multiphoton artefacts in time-resolved pump probe experiments

Marie Luise Gruenbein (Max-Planck-Institute for Medical Research)

15/10/2020, 16:10

Invited

Light is important for organisms from all domains of life, serving as an energy resource or carrier of information initiating intra- or intercellular signaling. Photosensitive proteins, endowed with a light-absorbing chromophore, enable this. Obtaining direct structural information to understand the underlying molecular mechanisms is not only important for the fundamental understanding of...

33. X-ray Emission Spectroscopy at X-ray Free Electron Lasers: Limits to Observation of Unperturbed Electronic Structures.

Dr Yulia Pushkar

15/10/2020, 16:40

Invited

Modern free electron lasers provide intense X-ray pulses with ~1012 photons within ~10-100 femtoseconds. Such pulses enable new experimental techniques and provide unique opportunities for investigation of electronic and nuclear dynamics on their intrinsic time-scales. Interaction of ultra-bright, ultra-short X-ray pulses with matter can induce a multitude of nonlinear excitation processes...

36. Correcting Non-isomorphism

Dr James M. Holton (University of California, San Francisco)

15/10/2020, 17:10

Invited

The problem of non-isomorphism has plagued macromolecular crystallography since the beginning [1, 2, 3], and it is essentially unavoidable in radiation damage studies. The unit cell changes with dose and that means the molecules in the cell must be adjusting somehow to the new cell. This will change the structure factors, but what if the molecular distortions could be corrected? Rigid-body...