Schiltz, M.Kvick, A.Svensson, O. S.Shepard, W.delaFortelle, E.Prange, T.Kahn, R.Bricogne, G.Fourme, R.2006-03-292006-03-292006-03-29199710.1107/S0909049597008571https://infoscience.epfl.ch/handle/20.500.14299/229013A protein crystallography experiment at the xenon K-edge (lambda = 0.358 Angstrom) has been successfully carried out at the materials science beamline (BL2/ID11) of the ESRF. The samples used in this methodological study were crystals of porcine pancreatic elastase, a 26 kDa protein of known structure. The diffraction data are of excellent quality. The combination of isomorphous replacement and anomalous dispersion of a single xenon heavy-atom derivative allowed accurate phase determination and the computation of a high-quality electron density map of the protein molecule. This is the first fully documented report on a complete protein crystallography experiment, from data collection up to phase determination and calculation of an electron density map, carried out with data obtained at ultra-short wavelengths. Experimental considerations as well as possible advantages and drawbacks of protein crystallography at very short and ultra-short wavelengths are discussed.text::journal::journal article::research article