ISSN:
1600-5767
Source:
Crystallography Journals Online : IUCR Backfile Archive 1948-2001
Topics:
Geosciences
,
Physics
Notes:
A simple method for the preparation of isomorphous xenon derivatives is presented. A device has been designed that allows diffraction studies on protein crystals under xenon gas pressures up to 50 × 105 Pa. Crystal mounting and X-ray data collection do not significantly differ from standard techniques. Tests carried out on crystals of the protein porcine pancreatic elastase reveal a single xenon binding site with high occupancy at a pressure of 8 × 105 Pa. Xenon binding to several other crystallized proteins has also been investigated and results indicate that the method is generally applicable. Time-resolved studies show that, at 297 K, xenon binding is essentially completed within a few minutes. At pressures above 106 Pa, successful data collection is hampered by X-ray absorption and by the formation of xenon hydrate. Absorption can be reduced by using short-wavelength radiation and by mounting crystals in small capillaries. To circumvent xenon hydrate formation, higher working temperatures and the use of cryoprotective mother liquors are advocated.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1107/S0021889894005923
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