On the influence of the incident photon energy on the radiation damage in crystalline biological samples

J Synchrotron Radiat. 2005 May;12(Pt 3):304-9. doi: 10.1107/S0909049505003328. Epub 2005 Apr 14.

Abstract

Two series of complete and highly redundant data sets were collected at wavelengths of 1.00 and 2.00 Angstroms on a cadmium derivative of porcine pancreatic elastase (PPE). Radiation damage to the sample was evaluated qualitatively by inspecting consecutive difference electron density maps during the course of the experiment. The nature of the radiation damage was found to be identical at both wavelengths and was localized primarily at the four disulfide bridges of PPE, the cadmium site and the two methionine residues. For a quantitative examination of the radiation damage, the decrease in the peak height of the cadmium ion in various electron density maps was exploited. Again, no significant difference in radiation damage between the two wavelengths was observed. This can be rationalized by considering the wavelength dependencies of the number of diffracted photons versus the number of absorbed photons and the energy deposited in the crystal by the latter.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Crystallization
  • Crystallography, X-Ray / methods*
  • Pancreatic Elastase / chemistry*
  • Pancreatic Elastase / radiation effects*
  • Photons
  • Protein Conformation / radiation effects
  • Swine

Substances

  • Pancreatic Elastase