IUCr journals

Papers from Second International Workshop on X-ray Damage to Crystalline Biological Samples

J. Synchrotron Rad. (2002). 9, 327–381

[Electron density maps pf HEWL] Electron density Fo–Fc maps of the Cys76-Cys94 disulphide bond in HEWL crystals. (a) and (b) (top left, right) for the first (left) and sixth (right) datasets from a native HEWL crystal, (c) and (d) (top left, right) for the first (left) and sixth (right) datasets from a crystal grown in the presence of 0.5 M ascorbate.

Macromolecular crystallographers are now actively investigating radiation damage processes in cryo-cooled (around 100 K) crystals. The aim is to understand them well enough to design minimization and/or mitigation strategies so that intense undulator-produced synchrotron beams can be fully utilized.

The November 2002 issue of the Journal of Synchrotron Radiation contains a collection of eight papers on this topic, with an introduction summarising the current status (Garman and Nave). Among the reported experimental results is evidence, provided by reduced specific structural damage and absorption spectra collected with a microspectrophotometer, that the introduction of a radical scavenger (0.5 M ascorbate co-crystallised with HEWL) can prolong the crystal lifetime in the x-ray beam (Murray and Garman). Physical and chemical processes relevant to the damage process are also discussed (O’Neill, Stevens and Garman).