title: Neutron protein crystallography: beyond the folding structure of biological macromolecules.
abstract: Neutron diffraction provides an experimental method of directly locating H atoms in proteins, a technique complementary to ultra-high-resolution X-ray diffraction. Three different types of neutron diffractometers for biological macromolecules have been constructed in Japan, France and the USA, and they have been used to determine the crystal structures of proteins up to resolution limits of 1.5-2.5 A. Results relating to H-atom positions and hydration patterns in proteins have been obtained from these studies. Examples include the geometrical details of hydrogen bonds, the role of H atoms in enzymatic activity, CH3 configuration, H/D exchange in proteins and oligonucleotides, and the dynamical behavior of hydration structures, all of which have been extracted from these structural results and reviewed. Other techniques, such as the growth of large single crystals and a database of hydrogen and hydration in proteins, are described.
authors.affiliation: Institute of Applied Beam Science, Graduate School of Science and Engineering, Ibaraki University, 4-12-1 Naka-Narusawa, Hitachi, Ibaraki 316-8511, Japan. niimura@mx.ibaraki.ac.jp
authors.forename: Nobuo
authors.initials: N
authors.lastname: Niimura
authors.forename: Robert
authors.initials: R
authors.lastname: Bau
mesh_terms: D003460:Crystallization; D004247:DNA / Q000737:chemistry*; D041961:Deuterium Exchange Measurement; D006639:Histidine / Q000737:chemistry; D006860:Hydrogen Bonding; D008958:Models, Molecular; D033363:Neutron Diffraction / Q000379:methods*; D011506:Proteins / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D011506:Proteins; D014867:Water; D006639:Histidine; D004247:DNA