Low power protein and powder crystallography using polycapillary optics.

摘要

This work describes the design and performance of low power protein and powder crystallography systems using polycapillary optics. For both systems, the low power ultra-bright micro-focus X-ray sources and polycapillary optics were characterized; optic alignment systems were designed to optimize coupling the optics and the sources; collimators with double apertures were used to block high-energy X-ray penetration and define the optic output beam sizes, divergences and intensities.; The protein crystallography systems with low power ultra-bright micro-focus sources combined with polycapillary collimating and slightly focusing optics were used to collect data sets of chicken egg white lysozyme by oscillation method. These data sets showed high quality by analysis with a conventional software package, DENZO. Diffraction still patterns have also been obtained by a low power source-strongly focusing optic combination. These patterns were analyzed by a newly developed program for processing diffraction patterns obtained with strongly convergent X-ray beams. Several powder sample data sets were collected with a powder crystallography system with polycapillary collimating and focusing optics combined with an low power ultra-bright micro-focus source. The data qualities were compared with data sets from the same samples taken with an Enraf-Nonius FR590 sealed-tube source system. The investigation shows that the application of polycapillary optics in powder diffraction also has a promising future.