QUANTITATIVE-ANALYSIS OF SYNCHROTRON LAUE DIFFRACTION PATTERNS IN MACROMOLECULAR CRYSTALLOGRAPHY

The reduction of X-ray diffraction data obtained by the Laue method to accurate integrated intensities is more complicated and much less fam iliar than the reduction of monochromatic data. Problems of data accur acy and completeness have hindered the wide use of the Laue technique in macromolecular crystallography. Its unique advantage, data-collecti on speed, has been exploited only in situations such as fast time-reso lved crystallography, to which monochromatic techniques are not as wel l suited. This paper reviews the major problems in data reduction in t he Laue technique and provides a unified solution to the problems in i ntegration of both streaky and spatially overlapping spots and data sc aling. This solution has been incorporated into a new Laue diffraction data-reduction software package, LaueView. Laue data sets from crysta ls of lysozyme and alpha-haemolysin have been processed to test this s olution, and demonstrate that Laue data sets can be reduced to yield s tructure amplitudes of at the very least the same quality as the best monochromatic data sets in terms of both accuracy and completeness.