Related Experiment Video
Updated: Jul 13, 2026

High Resolution Phonon-assisted Quasi-resonance Fluorescence Spectroscopy
Published on: June 28, 2016
Applications of single-wavelength anomalous dispersion at high and atomic resolution
D E Brodersen1, E de La Fortelle, C Vonrhein
1Macromolecular Crystallography, IMSB, Aarhus University, Gustav Wieds Vej 10c, DK-8000 Aarhus C, Denmark.
Abstract:
Two examples of the application of single-wavelength anomalous dispersion (SAD) in macromolecular structure determination are described, both using the statistical phasing program SHARP. For the holmium-substituted calcium-binding protein psoriasin (22.7 kDa), a set of accurate phases has been obtained to a resolution of 1.05 A without recourse to an atomic model of the molecule. The accuracy of the phases resulted in an electron-density map of a quality comparable to sigma(A)-weighted 2mF(o) - DF(c) maps derived from the final model refined with SHELX97. Comparison of the refined and SAD electron-density maps showed significant discrepancies resulting from the iterative refinement in reciprocal space. Additionally, it is shown that the structure of psoriasin can be determined from native data extending to 2.0 A alone by exploiting the minute anomalous signal from a bound zinc ion.
More Related Videos
Related Concept Videos
X-ray Crystallography
Diffraction
Diffraction is the change in the direction of travel experienced by an electromagnetic wave when it encounters a physical barrier whose dimensions are comparable to those of the wavelength of the light. X-rays are electromagnetic radiation with wavelengths about as long as the distance between neighboring...
X-ray Diffraction of Biological Samples
According to Bragg's law, when X-rays strike the sample positioned on a stage, the rays are scattered by the electron clouds around the sample atoms. The X-ray diffraction or scattering is caused by constructive interference of the X-ray waves that reflect off the internal crystal...
Super-resolution Fluorescence Microscopy
Determination of Crystal Structures

