Triple-axis X-ray diffraction analyses of lysozyme crystals.

High-resolution triple-axis X-ray diffraction techniques have been used to monitor the defect structure in hen egg-white lysozyme crystals. Analyses from the (440), (12;0) and (160) reflections showed significant differences in the intensity distribution around the respective reciprocal-lattice points. This work suggests that X-ray diffraction analytical methods developed primarily for relatively perfect inorganic crystals can be successfully applied to structurally defective macromolecular crystals. The analysis of defects at high angular resolution is complicated, however, by the observation that protein crystals lie at the convergence of the kinematic (ideally imperfect) and dynamic (ideally perfect) treatments of diffraction.