MX: Macromolecular Crystallography

Macromolecular Crystallography (MX, also referred to as Protein Crystallography or PX) is the most powerful method for determining the atomic three dimensional structures of large biological molecules. It is a vital tool for linking structure with function, for rational drug design, for investigating protein folding and for relating other structural information, such as evolutionary relationships, from biological molecules.

The Diamond MX beam lines allow structure determination by molecular replacement, where the structure of a related molecule is already known, by standard isomorphism replacement with heavy atoms and by Single wavelength Anomalous Dispersion (SAD) or Multiwavelength Anomalous Dispersion (MAD) measurements, in which the wavelength of the X-rays is tuned to be near or at the natural absorption wavelength of selected atoms in the macromolecule. This enables the detection of small differences in the diffraction pattern for reflections that are related as Friedel pairs and these differences allow phase determination to determine the structure through crystallographic methods.