IUCr journals

A novel strategy for the crystallization of proteins: X-ray diffraction validation

Acta Cryst. (2007). D63, 310–318 [doi:10.1107/S0907444906053303]

[Mellitic acid]A molecule of mellitic acid serves as the lynchpin of a hydrogen-bonding network between two bovine trypsin molecules in a crystal lattice.
An alternative strategy for the crystallization of macromolecules was recently proposed [McPherson & Cudney (2006). J. Struct. Biol. 156, 387–406] based on the promotion of lattice interactions by conventional, small molecules. This paper presents difference Fourier syntheses of crystals that validate the concept. Proteins, including trypsin, thaumatin, ribonuclease and lysozyme were observed (see figure) interacting in crystals through hydrogen-bonding networks involving such conventional organic molecules as mellitic, trimesic, sulfanilic, oxamic and aminobenzoic acids. The work opens new avenues for biological macromolecule crystallization.

S.B. Larson, J.S. Day, R. Cudney and A. McPherson