Rapid determination of hydrogen positions and protonation states of diisopropyl fluorophosphatase by joint neutron and X-ray diffraction refinement.

ABSTRACT: Hydrogen atoms constitute about half of all atoms in proteins and play a critical role in enzyme mechanisms and macromolecular and solvent structure. Hydrogen atom positions can readily be determined by neutron diffraction, and as such, neutron diffraction is an invaluable tool for elucidating molecular mechanisms. Joint refinement of neutron and X-ray diffraction data can lead to improved models compared with the use of neutron data alone and has now been incorporated into modern, maximum-likelihood based crystallographic refinement programs like CNS. Joint refinement has been applied to neutron and X-ray diffraction data collected on crystals of diisopropyl fluorophosphatase (DFPase), a calcium-dependent phosphotriesterase capable of detoxifying organophosphorus nerve agents. Neutron omi

SUBMITTER: Blum MM 

PROVIDER: S-EPMC2630072 | biostudies-literature | 2009 Jan

REPOSITORIES: biostudies-literature