IMAGINE: neutrons reveal enzyme chemistry

• Published in: Acta crystallographica. Section D, Biological crystallography. Biological crystallography., 2018-08, Vol.74 (8), p.778-786
• Main Authors: Schröder, Gabriela C., O'Dell, William B., Myles, Dean A. A., Kovalevsky, Andrey, Meilleur, Flora
• Format: Article
• Language: English
• Subjects: Atomic structure; Crystal structure; Crystallography; Crystals; Deuterium; deuterons; Diffraction; enzyme mechanisms; Enzymes; Enzymes - chemistry; Hydrogen; IMAGINE; Macromolecules; neutron crystallography; Neutron diffraction; Neutron Diffraction - instrumentation; Neutron Diffraction - methods; Neutron flux; Neutrons; Optics; Organic chemistry; Proteins; protons; Research facilities; Structural analysis; Wavelength
• ISSN: 2059-7983; 0907-4449; 2059-7983; 1399-0047
• DOI: 10.1107/S2059798318001626

Neutron diffraction is exquisitely sensitive to the positions of H atoms in protein crystal structures. IMAGINE is a high‐intensity, quasi‐Laue neutron crystallography beamline developed at the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory. This state‐of‐the‐art facility for neutron diffraction has enabled detailed structural analysis of macromolecules. IMAGINE is especially suited to resolve individual H atoms in protein structures, enabling neutron protein structures to be determined at or near atomic resolutions from crystals with volumes of less than 1 mm3 and unit‐cell edges of less than 150 Å. Beamline features include elliptical focusing mirrors that deliver neutrons into a 2.0 × 3.2 mm focal spot at the sample position, and variable short‐ and long‐wavelength cutoff optics that provide automated exchange between multiple wavelength configurations. This review gives an overview of the IMAGINE beamline at the HFIR, presents examples of the scientific questions being addressed at this beamline, and highlights important findings in enzyme chemistry that have been made using the neutron diffraction capabilities offered by IMAGINE. The capabilities of the IMAGINE neutron protein diffractometer at the Oak Ridge National Laboratory High Flux Isotope Reactor and highlights of the first five years of the scientific program are reviewed.