Neutron Protein Crystallography: Beyond the Folding Structure


Neutron diffraction provides an experimental method of directly locating hydrogen atoms in proteins, a
technique complementary to ultra-high-resolution X-ray diffraction. A neutron diffractometers for biological
macromolecules has been constructed in Japan, and it has been used to determine the crystal structures of proteins up to
resolution limits of 1.5-2.5 A. Results relating to hydrogen positions and hydration patterns in proteins have been
obtained from these studies. Examples include the geometrical details of hydrogen bonds, the role of hydrogen atoms in
enzymatic activity, CH3 configuration, HID exchange in proteins and oligonucleotides, and the dynamical behavior of
hydration structures, all of which have been extracted from these structural results and reviewed.
Keywords: Neutron, protein, crystallography, hydrogen, hydration, I-PARC, SNS. N. Niimura;Institute of Applied Beam Science, Graduate School of Science and Engineering, Ibaraki University,
4-12-1 Naka-Narusawa, Hitachi, Ibaraki 316-8511, Japan