The Perfection of Protein Crystals Probed by Direct Recording of Bragg Reflection Profiles with a Quasi-Planar X-ray Wave

Profiles of Bragg reflections from earth-grown crystals of lysozyme from hen egg-white and collagenase from Hypoderma lineatum were directly recorded with a quasi-planar X-ray wave. One crystal of each protein was chosen for a detailed investigation. Each sample is shown to consist of only a few (three and two, respectively) highly ordered domains, misoriented with respect to each other by a few arc s. The smallest rocking widths were observed for the large domain of the collagenase sample (FWHM corrected for instrumental broadening: 0.0016° for a strong reflection at 3 Å resolution). With appropriate improvements, this method might become a quantitative tool for characterizing the perfection of crystals from biological macromolecules.