HPC to reduce crystal disorder

In some cases, application of pressure can improve the as-grown X-ray diffraction quality of protein crystals. This is presumably a result of increased pressure favoring a more ordered packing of the molecules in the crystal, i.e.reduced lattice disorder.

The use of HPC to reduce lattice disorder has been described in (Huang et al., 2016, J. Appl. Cryst., 49, 149-157). Examples of general reduction in disorder include:

In the endosomal sorting protein snf7, limiting resolution improved from 2.4 to 1.6 Å.  This was accompanied by a dramatic reduction in unit cell dimensions due to a shape change of the protein molecules which resulted in tighter packing (an unusual effect; generally unit cell changes are more subtle). (Tang et al., eLife 2015 Dec 15, e 12548).

What can HPC: resolution improved from 2.4 to 1.6 Å

In lpg1496, an effector protein from the Gram-negative bacterium Legionella pneumophila, HPC at 350 Mpa resulted in improved resolution (~2.4 to 1.45 Å) and a large decrease in mosaic spread.

What can HPC: improved resolution from ~2.4 to 1.45 Å

In the O-methyltransferase Calo6, the resolution improved from 3.4 to 2.3 Å and the anisotropy of the diffraction was much reduced.

What can HPC: resolution improved from 3.4 to 2.3 Å

In human glutaminase C, HPC was able to resolve non-merohedral twinning, reducing multiple twin domains to a single lattice.

What can HPC: resolve non-merohedral twinning