title: Preliminary time-of-flight neutron diffraction study on diisopropyl fluorophosphatase (DFPase) from Loligo vulgaris.
abstract: The enzyme diisopropyl fluorophosphatase (DFPase) from Loligo vulgaris is capable of decontaminating a wide variety of toxic organophosphorus nerve agents. DFPase is structurally related to a number of enzymes, such as the medically important paraoxonase (PON). In order to investigate the reaction mechanism of this phosphotriesterase and to elucidate the protonation state of the active-site residues, large-sized crystals of DFPase have been prepared for neutron diffraction studies. Available H atoms have been exchanged through vapour diffusion against D2O-containing mother liquor in the capillary. A neutron data set has been collected to 2.2 A resolution on a relatively small (0.43 mm3) crystal at the spallation source in Los Alamos. The sample size and asymmetric unit requirements for the feasibility of neutron diffraction studies are summarized.
authors.affiliation: Institute of Biophysical Chemistry, J. W. Goethe University Frankfurt, Max-von-Laue-Strasse 9, D-60438 Frankfurt, Germany.
authors.forename: Marc-Michael
authors.initials: MM
authors.lastname: Blum
authors.forename: Alexander
authors.initials: A
authors.lastname: Koglin
authors.forename: Heinz
authors.initials: H
authors.lastname: Rüterjans
authors.forename: Benno
authors.initials: B
authors.lastname: Schoenborn
authors.forename: Paul
authors.initials: P
authors.lastname: Langan
authors.forename: Julian C-H
authors.initials: JC
authors.lastname: Chen
mesh_terms: D000818:Animals; D005240:Feasibility Studies; D049834:Loligo / Q000737:chemistry / Q000201:enzymology*; D033363:Neutron Diffraction / Q000379:methods*; D044345:Phosphoric Triester Hydrolases / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D044345:Phosphoric Triester Hydrolases; C020061:diisopropyl-fluorophosphatase