title: Seeing the chemistry in biology with neutron crystallography.
abstract: New developments in macromolecular neutron crystallography have led to an increasing number of structures published over the last decade. Hydrogen atoms, normally invisible in most X-ray crystal structures, become visible with neutrons. Using X-rays allows one to see structure, while neutrons allow one to reveal the chemistry inherent in these macromolecular structures. A number of surprising and sometimes controversial results have emerged; because it is difficult to see or predict hydrogen atoms in X-ray structures, when they are seen by neutrons they can be in unexpected locations with important chemical and biological consequences. Here we describe examples of chemistry seen with neutrons for the first time in biological macromolecules over the past few years.
authors.affiliation: Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA. langanpa@ornl.gov
authors.forename: Paul
authors.initials: P
authors.lastname: Langan
authors.forename: Julian C-H
authors.initials: JC
authors.lastname: Chen
mesh_terms: D000596:Amino Acids / Q000737:chemistry; D018360:Crystallography, X-Ray; D043542:DNA, Z-Form / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D009502:Neutrons; D014867:Water / Q000737:chemistry
chemical_list: D000596:Amino Acids; D043542:DNA, Z-Form; D014867:Water; D006859:Hydrogen