Neutron Protein Crystallography: Beyond the Folding Structure


Neutron diffraction provides an experimental method of directly locating hydrogen atoms in proteins, atechnique complementary to ultra-high-resolution X-ray diffraction. A neutron diffractometers for biologicalmacromolecules has been constructed in Japan, and it has been used to determine the crystal structures of proteins up toresolution limits of 1.5-2.5 A. Results relating to hydrogen positions and hydration patterns in proteins have beenobtained from these studies. Examples include the geometrical details of hydrogen bonds, the role of hydrogen atoms inenzymatic activity, CH3 configuration, HID exchange in proteins and oligonucleotides, and the dynamical behavior ofhydration structures, all of which have been extracted from these structural results and reviewed.Keywords: Neutron, protein, crystallography, hydrogen, hydration, I-PARC, SNSPACS: 83.85.Hf, 87.15.-v