title: Optimizing crystal volume for neutron diffraction: D-xylose isomerase.
abstract: Neutron diffraction is uniquely sensitive to hydrogen positions and protonation state. In that context structural information from neutron data is complementary to that provided through X-ray diffraction. However, there are practical obstacles to overcome in fully exploiting the potential of neutron diffraction, i.e. low flux and weak scattering. Several approaches are available to overcome these obstacles and we have investigated the simplest: increasing the diffracting volume of the crystals. Volume is a quantifiable metric that is well suited for experimental design and optimization techniques. By using response surface methods we have optimized the xylose isomerase crystal volume, enabling neutron diffraction while we determined the crystallization parameters with a minimum of experiments. Our results suggest a systematic means of enabling neutron diffraction studies for a larger number of samples that require information on hydrogen position and/or protonation state.
authors.affiliation: Hauptman-Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, NY 14203, USA. esnell@hwi.buffalo.edu
authors.forename: Edward H
authors.initials: EH
authors.lastname: Snell
authors.forename: Mark J
authors.initials: MJ
authors.lastname: van der Woerd
authors.forename: Michael
authors.initials: M
authors.lastname: Damon
authors.forename: Russell A
authors.initials: RA
authors.lastname: Judge
authors.forename: Dean A A
authors.initials: DA
authors.lastname: Myles
authors.forename: Flora
authors.initials: F
authors.lastname: Meilleur
mesh_terms: D019747:Aldose-Ketose Isomerases / Q000737:chemistry* / Q000378:metabolism; D001665:Binding Sites; D002384:Catalysis; D003460:Crystallization; D006859:Hydrogen / Q000737:chemistry; D008956:Models, Chemical; D033363:Neutron Diffraction; D009502:Neutrons; D011485:Protein Binding; D013302:Streptomyces / Q000201:enzymology; D014994:Xylose / Q000378:metabolism
chemical_list: D006859:Hydrogen; D014994:Xylose; D019747:Aldose-Ketose Isomerases; C023298:xylose isomerase