Quantitative assessment of radiation damage in a thin protein crystal.

Radiation damage is a limiting factor for high resolution structural determination of protein crystals. We have used the median and quartile values of Ne exposures and the structural disordering factor (delta B) to describe the crystalline disordering due to radiation damage in thin crystals of crotoxin complex embedded in glucose at room and low temperatures and in ice embedded crystals. By approximating the radiation damage to follow first order kinetics, we applied a correction to the diffraction intensities from patterns with high accumulated exposures. We used the structural similarity factor (R) to show that, for some data, the effectiveness of the correction can be as good as those in protein X-ray crystallography.