Crystallization Technique for Strain-free Protein Crystals Using Cross-linked Seed Crystals

In this study, we show using X-ray diffraction (XRD) rocking-curve measurements that local strain in tetragonal hen egg white (HEW) lysozyme crystals can be removed to a large degree by utilizing seed crystals cross-linked with glutaraldehyde. We also find that misorientation between subgrains and subgrain size decrease when employing cross-linked seed crystals, which suggests that subgrain formation in tetragonal HEW lysozyme crystals can be controlled using this technique. The ideal mosaic structure of proteins that enables the collection of accurate integrated intensities of the diffracted waves is also discussed using tetragonal HEW lysozyme crystals as a model protein.