More uses of HPC

In addition to improving diffraction quality, HPC causes other changes in crystals, which can help us to understand their interior structure.

Pressure can affect properties such as color through subtle effects on molecules. For example the protein citrine is yellow at ambient pressure but changes at high pressure. HPC revealed corresponding changes in the molecular structure with pressure (Barstow et al. 2009, Biophy. J., 97, 1719-1727).

Corresponding changes in the molecular structure with pressure

Pressure can also act to stabilize bound ligands, for example ATP-γS in the KtrAB K+ transporter (Albright et al. 2006, Cell 126, 1147-1159).

Albright, Pressure to stabilize bound ligands


HPC using various gases at relatively low pressure can trap gaseous reactants in crystals.

Pressurizing with an inert gas such as Kr or Xe, and then switching to He, all at ~200 Mpa, can introduce Kr or Xe in a few well-ordered sites, for phasing using the anomalous diffraction of the noble gas atoms (Kim et al. 2006, Acta Cryst. D62, 687-694).

Pressure affects not only the macromolecules in a crystal, but also the water that is always present. Experiments using HPC have increased our knowledge of this very common but fascinatingly complex material (Kim et al. 2009, PNAS 106, 4596-4600).